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Патент USA US2558943

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July 3, 1951
E. J. DILLMAN ETAL
' 2,558,938
HEAT PUMP AND CONTROL MEANS
Filed Dec. 30, 1948’
4 Sheets-Sheet 1
~23.03.%
_
'
~
vINVENTORS
mm“
July 3, 1951
E. J. DILLMAN ETAL
- 2,558,938
HEAT PUMP AND CONTROL MEANS
Filed Dec. 30, 1948
4 Sheets-Sheet 3
FIG. 4 '
INVEV TORS
m ATTORNEY
Patented July 3, 1951
2,558,938
UNITED STATES PATENT QFFlCE
2,558,938
HEAT PUMP AND CONTROL MEANS
Earnest J. Dillman and Thomas E. Noakes, De
troit, Micln,v assignors to Detroit Lubricator
Company, Detroit, Mich., a corporation of
Michigan
1
Application December 30, 1948, Serial No. 68,246
21 Claims. (Cl. 62-3)
This invention relates to new and useful im
provements in refrigeration systems and control
means therefor and more particularly to reversi
ble refrigeration systems vcommonly known as
2
frigeration system and several detail views of the
component parts thereof, in which drawings:
Figure l is a diagrammatic view of a reversible
refrigeration system embodying this invention
heat pumps.
One of the objects of this invention is to pro
and showing the parts thereof in position for a
vide a new and improved reversible refrigeration
Fig. 2 is a diagrammatic view of the system of
Fig. 1, but shows the parts of the system in posi
system.
heating cycle,
Another object is to provide a reversible re
tion for a cooling cycle,
frigeration system composed of simple and in 10 Fig. 3 is a longitudinal sectional view of one of
expensive parts which are easily assembled for
the “three-way” flow directing valves used in this
operation.
system and in the actuated position of Fig. 2,
Another object is to provide a reversible re
Fig. 4 is a longitudinal sectional view of the
frigeration system which includes a pair of pilot
other of the “three-way” flow directing valves and
operated “three-way” valves for directing flow of 16 shown in the actuated position of Fig. 2,
refrigerant and having a means to prevent un
loading the refrigerant compressor by premature
operation of the flow directing valves.
Another object is to provide a reversible re
frigeration system which has a pair of pilot op
erated “three-Way” ?ow directing valves which
Fig. 5 is a longitudinal sectional view of the
solenoid operated pilot valve for this system and
shown in the valve actuated position of Fig. 2,
Fig. 6 is a sectional view of the pilot valve
20 shown in Fig. 5 taken on the section line 6-6,
Fig. 7 is a sectional view similar to that shown
are operated by a momentary pressure differential
in Fig. 5 but showing the valve member in the
across a valve actuating diaphragm and which
position showngdiagrammatically in Fig. 1,
are held in an actuated position by a pressure
Fig. 8 is a longitudinal sectional view of the
differential across the closed valve members of .25 pressure differential switch used in this system
said valves.
and is shown in a closed position and,
Another object is to provide a reversible re
Fig. 9 is a horizontal section taken on the sec
frigeration system having a pressure operated
tion line 9—9 of Fig. 8.
flow directing valve and a novel solenoid operated
Referring to the drawings by characters of ref
pilot valve.
30 erence there is shown in Fig. 1 a refrigeration
Another object is to provide a reversible re
system of the reversible type commonly known as
frigeration system having a ?ow directing valve
a heat pump which comprises essentially a com
means which is electrically operated and having
pressor I, ?rst and second heat exchangers 2 and
a pressure differential switch controlling said
3 and a refrigerant receiver 4. The heat ex
valve means which is operable to prevent unload
35 changers 2 and 3 are operable to be used either
ing of the compressor by operation of said valve
as a refrigerant condenser or a refrigerant evap
means at the start of operation of the refrigera
orator, according to the direction of operation of
tion system before a suitable pressure differential
the refrigeration cycle. The system in the position
is established across the system.
of operation shown in Fig. 1 is arranged for a
Another object is to provide, as a subcombina
40 heating cycle and the heat exchanger 2 is located
tion to a reversible refrigeration system, a novel
within‘ the space which is to be heated and is
solenoid operated pilot valve.
operating as a condenser while the heat exchanger
Other objects will become apparent from time
3 is located outside of the space to be heated and
to time throughout the speci?cation and claims
is operating as a refrigerant evaporator. There
as hereinafter related.
45 are a pair of “three-way” valves 5 and 6 which
This invention comprises the new and improved
are operable to determine to which of the heat
construction of the component parts of this sys
exchangers 2 or 3 the refrigerant shall flow for
tem and the cooperative connection of said parts
condensation or for evaporation and hence to
to each other to provide an improved reversible
determine the direction of operation of the re
refrigeration system which will be described more 50 frigeration cycle.
fully hereinafter and the novelty of which will be
The term “three-way” as hereinafter used de
particularly pointed out and distinctly claimed.
notes a valve of the type which has three open
In the accompanying drawings to be taken as
ings thereinto and which has a valve member or
part of this speci?cation there is clearly and fully
members which control the flow to or from one
illustrated one preferred embodiment of this re
or the other of two of the openings. For exam
3
2,658,988
ple, the valve may have a single inlet and a pair
of outlets, the valve member or members deter
mining through which of the outlets flow is to
4
ment with its valve seat 48. The end wall mem—
ber 52 has one or more apertures 56 therein open
ing into a, recess 51 which is closed by a valve
operating diaphragm 58. The diaphragm 58 is
be permitted or the valve may have the reverse
operatively connected as at 59 to the valve stem
operation, that is, there may be- two inlets and
49 for actuating the valve members 53 and 54.
a single outlet and the valve member determin
There is a cover member 60 which is secured on
ing from which of the two inlets ?ow is to be
the end of the casing 36 adjacent the diaphragm
permitted to the single outlet. If reference be
58 and which encloses therewith a space BI which
had to Figs. 3 and 4 there is shown in greater
detail the “three-way” valves 5 and 6 respectively. 10 is operable to receive a valve actuating pressure
through an aperture 62 in said cover member.
The valve 5, as shown in Fig. 3, comprises a
Referring back to Fig. l we ?nd that the inlet
valve casing 'I having an inlet 8 and a pair of
8 to the “three-way” valve 5 is connected by a
outlets 9 and I8. Within the casing ‘I there are
conduit 63 to the outlet or compression side of
two plugs or wall members II and I2 which are
the compressor I. The outlet I6 of the valve
screw-threadedly positioned therein and which
5 is. connected by a conduit 64 to one end 65
divide the casing ‘I into three chambers I3, l4
of the heat exchanger 2. The valve outlet 9 is
and I5. The wall members II and I2 each have
connected by a conduit 66 to one end 67 of the
valve ports I6 and I7 therein and have valve
heat exchanger 3. The inlets 31 and 38 to the
seats I8 and I9 facing inwardly of the middle
valve chamber I4. There is a valve member 28 20 “three-way” valve 5 are connected by conduits
68 and 69 respectively to the other ends ‘Ill and
which is positioned in the middle valve chamber
‘II respectively of the heat exchangers 3 and 2.
I4 and which is movable between the valve seats
The outlet 39 of the “three-way” valve 6 is con
I8 and I9. The valve member 20 cooperates with
nected by a conduit ‘I2 to the inlet or suction side
said valve seats by engagement of resilient valve
face members 2I and 22 respectively therewith. 25 of the compressor I. The conduit 12 has a liquid
trap 13 therein and also has a portion 14 which
The valve member 20 is carried by a valve stem
is arranged for heat exchange with the outlet
23 which extends through the ports I6 and I?
84 ‘from the refrigerant receiver 5. The end
into the chambers I3 and I5 respectively and
portions 16 and H of the heat exchangers 3 and
which is guided at one end in a recess 24 in the
end wall 25 of the casing ‘I and at the other end 30 2 respectively are connected by conduits ‘I5 and
‘IE to the arms of a “cross” Tl which is connected _
through an aperture in the wall member 25. The
to the inlet ‘I8 of the receiver 4. The conduits
outer surface of the wall member 26 has a recess
‘I5 and 76 each have check valves ‘I9 and 36
21 therein which is closed by a ?exible diaphragm
therein which open on a pressure differential and
28 of rubber or other organic elastomeric ma
?ow toward the receiver inlet ‘I8. The ends 65
terial. There are provided one or more aper
and 6? of the heat exchangers 2 and 3 are con
tures 29 in the end wall 26 for ‘application of
nected by conduits 8i and 82 to the legs of a
refrigerant pressure from the chamber I3 to the
T connection 83 which is connected to the out
diaphragm 28. The diaphragm 28 is connected
let 84 from the receiver "4. The conduits 8i
as at 38 to the valve stem 23 for actuating the
valve member 20. There is a cover member 3| 40 and 82 each have positioned therein and adjacent
the heat exchangers 2 and 3 refrigeration ex
which closes the end of the casing ‘I adjacent the
pansion valves 85 and 86 respectively. The ex
diaphragm 28 and which encloses therewith a
pansion valves 85 and 86 are of the thermostatic
space 32 which is operable to receive a valve ac
type and include a pressure responsive means
tuating pressure through a connection such as a
conduit secured in an aperture 33 in the cover 45 for establishing a de?nite maximum operating
pressure for these valves. Such a means for
member 3I. There is a ?anged disc member 34
limiting the pressure of operation of thermo
which is carried by the end of the valve stem 23 in
static expansion valves is inherent in expansion
the valve chamber I5 and which is operable to
valves of the “gas-charged” type and they may
receive one end of a helical spring 35 the other
end of which is positioned against the end wall 25 50 also be provided by an auxiliary pressure re
sponsive diaphragm in an expansion valve of
of the valve casing and which is operable to urge
the “liquid-charged” type which has a lost mo
the valve member surface 2I toward engagement
tion arrangement to permit closing of the valve
with the valve seat I8.
independently of the temperature of the ther
The other “three-way” valve 6 comprises a
valve casing 36 having inlets 31 and 38 and an 55 mostatic bulb element. The former or “gas
charged” valve is clearly and fully illustrated in
outlet 39. There are within the casing 36 a pair
Patent No. 1,971,695 to Ploeger and one form
of plug members or internal dividing walls 40 and
of the latter type or “liquid-charged” valve hav
4| which divide the casing 36 into three cham
ing a maximum pressure limiting feature is
bers 42, 43, and 44. The wall members 40 and
4| have valve ports 45 and 46 therethrough and 60 illustrated in Patent No. 2,192,117 to D. D. Wile.
The valves 85 and 86 have thermostatic bulb
outwardly facing valve seats 41 and 48 respec
elements 87 and 88 which are responsive to tem
, tively. There is a valve stem 49 which extends
perature of refrigerant in the conduits 59 and
through the ports 45 and 46 and which is guided
68 respectively to throttle the operation of these
at one end in a recess 50 in the end wall 5| of
the casingv '36 and which is guided at the other 65 valves for maintaining a constant superheat
end in an aperture in an end wall member 52.
Three are a. pair of valve members 53 and 54
setting, subject, however, to the aforementioned
pressure limiting feature. There is a solenoid
operated pilot valve 89 which has inlets con
which are positioned in the chambers 42 and 44
nected by conduits 9B and 5| respectively to the
respectively and which are spaced so that when
the valve member 53 is closed against the valve 70 high pressure side of the system ‘at the refrig
erant receiver 4 and to the low pressure side
' seat 41, the valve member 54 is in an open po
of the system at the suction line conduit ‘I2, the
sition relative to its valve seat 48. There is a
valve 89 also having an outlet which is operable
spring 55 which is positioned between the valve
to be connected by conduit 92 to the apertures
member 54 and the wall 5I of the casing and
which urges the valve member 54 toward engage 75 33 and 82 on the “three-way” valves 5 and 6 for
.auaoad
‘
5
~
supplying pressure to the diaphragm chambers
32 and 6|.
The pilot valve 89 is shown in detail inFlgs.
5, 6, and 7, reference being made thereto for a
more detailed description as follows: The valve
69 comprises a hollow casing 93 which has alined
upper and lower apertures 94 and 95 in the
upper and lower walls thereof adjacent the end
wall 96. 1 There is an end opening 91 opposite
8
H9. Upon energization of the solenoid coil I23
the plunger I20 is moved upward quickly so that
the lower plunger shoulder I28 strikes the lever
end portion II8 with an impact blow and moves
it and the spring II5 to an overcenter position
whereirom the force of the spring II5 continues
movement of the lever III to an up position.
When the plunger I20 is in its up position and
the solenoid coil I23 is energized the end por
the end wall 96 in which there is screw-thread 10 tion II8 of the lever III comes to rest inter
edly positioned a plug or wall member 88' having
mediate the plunger shoulders I21 and I29 so
an outlet aperture 99 therethrough. There are
that the solenoid coil I23 is not required to
inlet ?tting members I00 and IN which are
supply the force required for holding the valve
screw-threadedly held in the apertures 94 and
member I04 in its down position. In this up
95 respectively and which have tubular projec 15 ward position of the lever III the spring II5
tions I02 and I03 which extend into the end of
exerts an upward force on the lever substan
the casing 93 and provide a guide means for a
tially equal to the weight of the plunger I20 for
valve member I04. The inlet ?tting members
holding the valve member end portion I06 closed
I00 and IIII are each hollow and provide inlet
against the valve seat I08. Upon deenergization
passages I00" and I0Ia respectively. The valve 20 of the solenoid coil I23 the solenoid plunger I20
member I04 has valve ends I05 and I06 which
is released and strikes the lever end portion H9
cooperate with valve seat members I01 and I08
with an impact force which together with the
respectively in the inlet ?ttings I00 and IN.
weight of the plunger I20 is operable to over
The valve member I04 is of a length such that
come the force of the spring “5 to move the
when the valve end I06 is closed against the 25 lever III and the valve member I04 to‘the posi
valve seat I08 the valve end I05 is open rela
tion from which it started as is indicated in Fig. 7.
tive to its valve seat I01.
There is a bracket
member I09 positioned within the casing 93 ad
jacent the valve member I04 and which carries
Returning to Fig. 1 it is seen that the solenoid
coil I23 of the valve 89 is connected to an open
switch I29 which upon closing is operable to
a fulcrum or pivot pin “0 for a valve operat 30 energize the aforementioned solenoid coil. The
ing lever ‘III. The valve lever III carries at
switch I29 is connected in series with the closed
one end a pin II2 which ?ts a slot H3 in the
contacts of a, pressure differential switch I30
valve member I04 and which is operable upon
which is connected by a conduit I3I to the inlet
movement of the lever III to move the valve
side of. the refrigerant receiver 4 and by a con
member I04. The bracket I09 has a project 35 duit I32 to the suction or return line 12 to the
ing pin portion II4 which supports a supporting
compressor I. The pressure differential switch
member for an overtravel spring II5 which has
I30 is responsive to a differential pressure be
its other end supported by a similar projecting
tween the high pressure side and the low pres
member I I6 carried by an upturned projection
sure side of the system and is operable to pre
'II1 on the lever III. The free end portion II8 40 vent energization of the solenoid coil I23 upon
of the lever III extends toward the end wall
closing the switch I29 unless there is a predeter
98 and has a slot II9 therein for receiving the
mined differential of pressure established across
the system.
~
end of a solenoid plunger I20. Adjacent the
end wall 98 of the casing 93 and in the upper
The pressure differential switch I30 is shown in
wall thereof there is an aperture I2I which has
detail in Figs. 8 and 9,>reference being had there
screw-threadedly secured therein a plug mem
to for a more complete description which fol
ber I22 which supports and has sealed thereon
lows: The pressure differential switch I30 com
a solenoid coil I 23 for operating this valve. ‘ prises a switch casing I33 having an upper wall
The solenoid coil I23 encloses the plunger I20
I34 and a lower wall I35. There is a low pres
which is shown in Fig. 5 in an energized or up 50 sure inlet ?tting I36 having an inlet passage I31
position. The plunger I20 carries thereon a
therethrough and which is carried by the upper
Wall I34 of the casing I33. There is a high pres
sure inlet ?tting I38 which has an inlet passage
I39 and which is carried by the lower wall I35
“kick-01f” force for moving the plunger down 55 of the casing I33. There is a pressure responsive
ward upon de-energization of the coil I23. The
bellows I40 which is positioned within the end
lower end of the plunger I20 has an annular
of the low pressure ?tting I36 and which is se
groove therein providing a reduced portion I 26
cured and sealed to the walls thereof and which
which has upper and lower shoulders I21 and
has one end secured and sealed to the end por
I28 respectively. When the solenoid coil I23 is 60 tion “I of a thrust rod I42. There is a similar
de-energized and the plunger I20 is resting on
bellows I43 which is secured to the walls of the
the end portion II9 of the lever III, the lever
high pressure ?tting I38 and which has a thrust
III has assumed a downwardly extending posi
head I44 secured thereto and which abuts the
tion as shown in Fig. '7 and holds the valve mem
other end I45 of the thrust rod I42. Within the
ber I04 in an up position closing the outlet 65 casing I33 there is pivotally supported a lever
passage IBM. In this position the overtravel
member I 46 which carries on its free operating
spring H5 is substantially on center relative to
end a U-shaped contact carrying arm I41. The
the fulcrum I I0 for the lever I II and the plunger
lever I46 is fulcrumed to the walls of the casing
I20 is being supported by the lever end portion
I33 by pivot pins or screws I48 and I49. The
H8, the valve member I04 thus being held closed 70 lever I 46 has a bifurcated end portion the legs
sleeve member I24 which is operable'to engage
the inner wall surface of the plug I22 and com
press a spring I25 to provide a starting or
by the weight of the plunger I20. When in
the down position of the lever the upper shoul
of which receive the pivot pins I48 and I49 and
between which legs is pivotally supported a rock
der I21 on the plunger I20 rests on the lever
able member I50. The member I50 has an ap
end portion II8, the plunger reduced portion
erture through its central portion and through
I26 having free movement through the lever slot 75 which extends the end portion I45 of the thrust
2,558,988
.
8
member I42, the member I42 being'secured to
and the outlet In to the conduit 64 which leads
the abutment member I58 for movement there
with by its pivot pin I5I. There are a pair of
contacts I52 and I53 which cooperate with a pair
of ?xed contacts I54 (only one of which is visible
in Fig. 8). Only a general description of the
construction of this switch is given herein as this
switch structure does not in itself form a part
to one end 55 of the heat exchanger or con
herein is shown and described more fully in the
patent application of E. J. Dillman, Serial No.
There can be no flow through the branch conduit
59 to and through the “three-way” valve 6 since
756,265, now Patent No. 2,548,817, granted April
17, 1951. The thrust rod I42 is urged downward
the valve member 54 therein is in a closed posi
tion, there being only a static high pressure in
this conduit. The high pressure refrigerant, now
liquified, passes through the conduit 16 and the
denser 2. When the compressed refrigerant
reaches the heat exchanger 2 at the end 85 it is
forced to go through this heat exchanger rather
than through the conduit 8| since the expansion
valve 85 is closed by the high pressure of refrig
erant in the conduit M. The compressed and
heated refrigerant- gives up its heat in passing
of the present invention since any suitable pres- .
sure di?erential switch would serve the needs of 10 through the condenser 2 and is discharged there
from intoa conduit 16 as a. refrigerant liquid.
‘ the system. This switch substantially as shown
by a spring I55 within the low pressure inlet ?t
ting I36. In operation this switch responds to
the differential of pressure supplied to the inlet
passages I31 and I39. Pressure from the low
I ‘
.
‘
3
.
‘ check valve 80 to the receiver 4.
From the re
ceiver 4 the liquiiied refrigerant passes out
side of the refrigeration system is supplied to 20 through the outlet 84 and conduit 82 to the ex
pansion valve 86 at the inlet end 61 of the heat
the inlet passage I31 and pressure from the high
exchanger or evaporator 3. Upon passing
side of the system is supplied to the inlet passage
through the expansion valve 86 the refrigerant
I39. During periods when the system is shut
?ows into the evaporator 3 and is evaporated and
down the pressure is equalized throughout the
receives heat from the outside air or other me
system and since the pressure in the passages
dium with which evaporator is in contact. It
I31 and I39 acting upon the bellows I48 and I43
should be noted that from the inlet ‘end 51 of
respectively is equal the force of the spring I55
the evaporator 3 the conduit 66 which runs to
will move the thrust member I42 downward to
one end of the “three-way” valve 5 transmits
rotate the lever I45 and open the contacts I52
and I53 from engagement with the ?xed con- . only a static low pressure since the valve 29 is
closed against its valve seat I8. From the outlet
tacts I54. However, when the system is started
1i! of the evaporator 3 ?ow through the conduit
a pressure differential is established so that
15 _is prevented even though the check valve 18
there is a low pressure in the passage I31 and
is arranged to open upon'?ow toward the receiver
a high pressure in the passage I39. This di?er
4 since the refrigerant in the conduit 15 is at a
ential of pressure acts upon the bellows I43 and
low pressure and the refrigerant on the other side
I40 respectively and upon reaching a predeter
of the check valve 19 is at a high pressure. The
mined differential will cause the bellows head
refrigerant ?owing from the outlet end we of
I44 to move upward and move the thrust rod
the evaporator 3 passes through the conduit 68
I42 to rotate the lever I46 ‘and close the con
tacts I52 and I53 against the ?xed contacts I54. 40 to the inlet 31 of the "three-way” valve 6. Re
frigerant entering the “three-way” valve 5
In operation this system functions generally as
through the inlet 31 passes through the open»
follows: Referring to Fig. l we ?nd the various
valve port 46 and out through thev outlet 39 to
component parts of this system in position for
the suction line or return conduit 12 leading
a heating cycle, that is, the heat exchanger 2
back to the inlet side of the compressor I. There
which is positioned inside the room or other
is a portion 14 of the suction line conduit 12
space which is to be heated or cooled is arranged ,
which is in heat exchange relation with the out
for operation as a refrigerant condenser and the
let 84 of the receiver 4 and is operable to cool
outside heat exchanger 3 is arranged for opera
the liquid refrigerant passing from the receiver
tion as a refrigerant evaporator. For most ef
4 and thereby increase the e?iciency of the heat
?cient operation the electrical connections from
transfer to the refrigerant upon evaporation.
the compressor I would normally be connected
The expansion valve 86 which controls ?ow of
in a circuit having a thermostatic control so
refrigerant into the evaporator 3 is thermostati
that the system would be started and stopped
cally modulated by its thermostatic power ele
according to the heat requirements of the space
ment which has a bulb element 88 responsive to
being heated or cooled, this feature, however,
the temperature of refrigerant at the outlet from
forming no part of this invention. Similarly the
the evaporator 3, and is operable to maintain a
switch I29 which is operable to energize the
constant and predetermined superheat for re
solenoid valve 89 for changing the operation of
frigerant passing through the evaporator, this
the system from heating to cooling and vice versa
would probably be a thermostatic switch so that 60 construction and operation being well known in
the art. It should be noted that the expansion
upon a su?icient rise of temperature the system
would automatically switch over to cooling oper-'
valve 86 opens because there is a differen
tial of pressure between that in the inlet 61‘
ation. When operating as a heating cycle the
to the evaporator 3 and the pressure in the
compressor I is compressing a refrigerant gas of
any suitable type and discharging the compressed 65 bulb element 88 and that the expansion valve
85 remains closed and is operable to pre
gas through the conduit 63 to the inlet 8 of the
vent ?ow through the conduit 8I because there
“three-way” valve 5. At this point of operation
is a high refrigerant pressure in the line 65. The
low pressure refrigerant gas is being supplied to
high pressure in the line 65 is operable to hold
the pressure receiving spaces 32 and GI back of
the valve actuating diaphragms 28 and 58 so that 70 the valve 85 closed independently of the tem
perature of the bulb element 81 because of the
these valves are held in the positions indicated
pressure limiting feature previously mentioned.
by the force of the springs 35 and 55 and the
The pilot valve 89‘ is a solenoid operated valve
‘ pressure differential across the valve members.
The compressed refrigerant gas is discharged
and has its outlet connected by conduit 92 for
from the valve 5 through the open valve port I1 75 supplying pressure to the diaphragm chambers
2,668,988
of the “three-way” valves 5 and 6 and has a pair
of inlets, one connected to the high pressure side
of the system and the other connected to the
low pressure side of the system. At this point of
operation the valve member end I05 is closed
against its valve seat IO‘I closing the high pres
sure inlet so that only low pressure is supplied to
the valve diaphragm chambers.
The pressure
10
rator). Flow through the conduit 82 from the
receiver 4 is prevented by the closed expansion
valve 86. Refrigerant from the conduit 8| passes
through the expansion valve 85 and into the
evaporator 2 wherein it is evaporated and ab
sorbs heat from the room or other space which
is being cooled and passes out through the com
duit 69 to the "three-way” valve 6. The ?ow
differential switch I38 is responsive to a differen
of refrigerant through the expansion valve 85
tial pressure between the high pressure side of l0 is modulated to maintain a constant superheat
the system and the low pressure side and when
as was valve 86 on the heating cycle. At the inlet
such a differential is established maintains its
to the evaporator 2 flow through the conduit 64
switch contacts closed and permits operation of
is prevented since the valve member 20 in the
the solenoid coil I23 which is in series with it.
“three-way” valve 5 is closed against the valve
When it is desired to change the operation of 15 seat I9 preventing ?ow through that line. At
this system to a cooling cycle, the switch I29 is
the outlet ‘II of the evaporator 2 ?ow through
closed either thermostatically or manually or by
the conduit 16 is prevented even though the check
any suitable means as may be desired and the.
valve 80 opens on flow toward the receiver 4 be
valve 89 is then energized and the solenoid
cause the pressure in the conduit 18 is low pres
plunger I20 moved to an up position and the 20 sure and the pressure on the other side of the
valve member I04 to a down position so that
check valve 80 is high pressure. From the ,_,con
the low pressure inlet to the valve is closed and
duit 69 the refrigerant vapor passes through the
the high pressure inlet is open. High pressure
open valve port 45 and through the outlet 39
refrigerant passes through the pilot valve 89yand
of the “three-way” valve 6 and is returned to the
the conduit 92 to the diaphragm chambers of the 25 compressor I through the suction line conduit
“three-way” valves 5 and 6 and produces a high
12. From the foregoing it is seen that there is
pressure therein. As is seen by reference to
herein provided a simple refrigeration system
Fig. 1, when the system is operated on a heating
which has an inside and an outside heat ex
cycle there is low pressure adjacent each of the
changer either of which may operate as a con
valve operating diaphragms and so when high. 30 denser or an evaporator and which has flow con
pressure is supplied to the diaphragm chambers
trolling valves which are operable to direct re
there is established a momentary pressure dif
frigerant ?ow for condensation to one or the
ferential across the diaphragms 28 and 58 which
other of the heat exchangers so that the system
is operable to move the respective valve members
may be reversed for heating or cooling as desired.
of the valves 5 and 6 to the positions indicated in 36 It should be noted that although the expansion
Fig. 2. When the valve members of the valves 5
valves 85 and 86 are preferably thermostatic
and 6 are moved to the positions indicated in
valves it would be possible to use pressure actu
Fig. 2 the system is arranged for cooling opera
ated or “automatic” valves for conditions where
tion and high pressure is being supplied to the
the outside air temperaturedoes not fall below
chambers adjacent the diaphragms 28 and 58 so 40 the evaporator temperature on the heating cycle.
that there is an equalization of the pressure
It should be also noted that by the arrangement
thereacross. However, there is a differential of
used in this system the "three-way” valves 5 and
pressure established across the closed valve mem
6 are actuated only by a momentary pressure dif
bers of these valves and this pressure differential
ferential across the diaphragms 28 and 58 and
is sufficient to maintain these valve members in 45 the valve members are held in their actuated po
their actuated position against the force of the
sitions by the differential of pressures thereacross
springs 35 and 55. When operating on a cooling
(although in the position of Fig. 1 the springs 35
cycle the compressed refrigerant gas is dis
and 55 are assisting the pressure differential in
charged from the compressor I through the con
holding the valve members closed). In each of
duit 63 to the inlet 8 of the “three-way” valve 5 50 the positions of the valves 5 and 6 as indicated
and then through the open valve port I6 and out
in Figs. 1 and 2 after the valve member has been
let 9 to the conduit 66 which leads to the inlet
moved to the position shown the pressure ad
end 61 of the heat exchanger 3 (which is now
mitted to the valve chambers adjacent the dia
operating as a refrigerant condenser). The re
phragms is the same as in the diaphragm actu
frigerant at the inlet to the condenser is pre 55 ating chambers. By this arrangement the forces
vented from bypassing the condenser through
exerted on the valve operating diaphragms are
the conduit 82 by the expansion valve 86 which
reduced and their operating lives materially
has a high pressure within it and is inoperative
extended.
.
to permit ?ow therethrough as was the expansion
The pressure differential switch I30 which is
valve 85 on the heating cycle. The hot refriger 60 provided to control the operation of the solenoid
ant passes through the condenser 3 and gives up
pilot valve 89 is operable as a safety means to
its heat to the outside air and is discharged
prevent unloading of the refrigerant compressor
through the condenser outlet 10 into the conduit
by premature actuation of the “three-way” ?ow
‘I5 which leads to the receiver 4. Flow from
controlling valves 5 and. 6. To explain this fea
the outlet ‘I0 of the condenser 3 through the 65 ture of the system reference is made again to Fig.
conduit 68 is prevented since the valve member
1. In Fig. 1 the system is shown for operation of
53 of the "three—way” valve 6 is in a closed po
the heating cycle and is then in an operating posi
sition and only a static pressure exists in this
tion. Let us assume for a moment that the sys
line. The refrigerant which ?ows through the
tem has been shut down and the pressures of the
conduit ‘I5 from the condenser 3 is operable to 70 refrigerant gas equalized throughout the entire
open the check valve ‘I9 and permit flow to the
system. At this point the pressures on the valve
receiver 4. From the receiver 4 refrigerant ?ows
actuating diaphragms of the “three-way” valves
through conduit ill and the expansion valve 85
5 and 6 will be equalized as would the pressures
to the inlet end 65 of the heat exchanger 2
across the valve members themselves and the
(which is now operating as a refrigerant evapo 75 valve members would be held in the positions
351'
2,558,988
11
.
12
said valve means, and safety means operable to
render said actuating means ine?'ective, said last
shown by the springs 35 and 55 respectively. The
pilot valve 89 would be in the position indicated.
named means including means operable upon,
occurrence of a predetermined pressure differen
tial across the system to render said actuating
means effective.
2. In a reversible refrigeration system, a com
Assume now that the pressure differential switch
I30 has been eliminated from the system and -
that the system has just been started in opera
tion. As the compressor l begins its operation
it begins to increase the pressure on the high
pressor, a ?rst heat exchanger, 2. second heat ex
side of the system by discharging compressed
changer, one of said heat exchangers being oper
crease the pressure on the low side of the system 10 able as a refrigerant condenser and the other as
a refrigerant evaporator according to the direc
by drawing in refrigerant gas from the suction
refrigerant through the conduit 63 and to de
line conduit 12. At this point the "three-way”
valves 5 and 6 are set for discharge of refrigerant
to the heat exchanger 2 for condensation and to
the heat exchanger 3 for evaporation. Now, be 15
fore the compressor I has had time to build up
to the normal operating pressure differential be
tween the highland low sides of the system sup
pose that the pilot valve 89 is energized and
switches from supplying low pressure to supply
ing high pressure to the diaphragm chambers of
the “three-way" valves 5 and 6.
At this point in operation the high pressure sup
plied through the pilot valve 89 is not yet up to
its maximum operating value and the low pres
sure on the other. side of the diaphragms is not
yet reduced to its proper value with the result
that a lower pressure di?erential is established
across the valve operating diaphragms 28 and 58.
This lower valve actuating pressure differential
will cause the valves 5 and 6 to be actuated very
slowly with the result that the flow from the
“three-way” valve 5 will be divided between the
tion of operation of the refrigeration cycle, valve
means operable to direct the ?ow of refrigerant
to one or the other of said heat exchangers for
refrigeration condensation, actuating means for
said valve means, and means operable to render
said actuating means ineffective, said last-named
means including pressure responsive means re
sponsive to the establishment of a predetermined
pressure differential across the system to render
said actuating means effective.
3. In a reversible refrigeration syste
, a com
pressor, a ?rst heat exchanger, a second heat
exchanger, one of said heat exchangers being
operable as a refrigerant condenser and the other
as a refrigerant evaporator according to the direc
tion of operation of the refrigeration cycle, valve
means operable to direct the flow of refrigerant
to one or the other of said heat exchangers for
refrigerant condensation, means cooperable with
and ‘operable to actuate said valve means to
- change the ?ow of refrigerant for condensation
from one of said heat exchangers to the other,
and means responsive to the differential of pres
outlet conduits 64 andtli to the heat exchangers
2 and 3 respectively. Similarly, the slow actua 85 sure between the high and low pressure sides of
the system and controlling the operation of said
valve means, said last-named means dominating
of the valve ports therein to be opened and thus
the operation of said valve actuating means.
‘to permit ?ow from both heat exchangers 2 and
4. In a reversible refrigeration system, a com
3 through conduits 69 and 68 respectively for
return through the suction line conduit 12 to 40.pressor, a ?rst heat exchanger, a second heat
exchanger, one of said heat exchangers being
the compressor I.- It is thus seen that by this
operable as a refrigerant condenser and the
premature actuation of the “three-way" valves
tion of the "three-way” valve 6 will cause both
5 and 6 the refrigerant passes through the re
ceiver 4 and is permitted to short circuit directly
other as a refrigerant evaporator according to
the direction of operation of the refrigeration
45 cycle, valve means operable to direct the flow of
refrigerant to one or the other of said heat ex
changers for refrigerant condensation, electri
cally operable means for actuating said valve
back to the compressor l and will unload the
compressor with. the result that the system would
be inoperative until shut down and restarted.
The pressure differential switch I30 is responsive
means to change the ?ow of refrigerant for
to the differential of pressure between the high
and low pressure sides of the system and is oper 50 condensation from one of said heat exchangers
to the other, and a pressure actuated switch
able to close at a, pressure di?erential which is
responsive to the differential of pressure be
sufficiently high to cause the “three-way” valves
tween the high and low pressure sides of the
5 and 6 to have their normal quick operation.
system and controlling the energization of said
By the use of this pressure differential switch in
the system the pilot valve 89 cannot be operated 55 valve actuating means.
5. In a reversible refrigeration system, a com
until the suitable pressure differential is estab
pressor, a ?rst heat exchanger, a second heat
lished between the high and the low sides of the
exchanger, one of said heat exchangers being
' system. The result of this arrangement is that
operable as a refrigerant condenser and the
even if the switch I29 is closed calling for a
other as a refrigerant evaporator according to
cooling cycle and the system is started after a
the direction of operation of the refrigeration
shut down period the system will begin its opera
cycle, valve means operable to direct the flow‘ of
tion on a heating cycle until the required pressure
refrigerant to one or the other of said heat ex
differential is established at which point the sys
changers for refrigerant condensation, means
tem will then change to cooling operation.
for actuating said valve means to change the
Having thus described the invention what is
?ow of refrigerant for condensation from one
claimed and desired to be secured by Letters
of said heat exchangers to the other, and means
Patent of the United States is:
controlling the operation of said valve actuat
1. In a reversible refrigeration system, a com
ing means and operable to prevent operation of
pressor, a ?rst heat exchanger, a second heat ex
the same at the start of the refrigeration cycle
70
changer, one of said heat exchangers being oper
until a pressure differential is established be
able as a refrigerant condenser and the other as
tween the high and low pressure sides of the
a refrigerant evaporator according to the direc
tion of operation of the refrigeration cycle, valve
system.
6. In a reversible refrigeration system, a com
means determining which of said heat exchangers
functions as a condenser, actuating means for 75 pressor, a ?rst heat exchanger, a second heat
9,558,988
13
exchanger, one of said heat exchangers being
operable as a refrigerant condenser and the
other as a refrigerant evaporator according to
the direction of operation of the refrigeration
cycle, valve means having a normal initial posi
tion directing refrigerant ?ow to said ?rst heat
exchanger for condensation and being operable
upon actuation to change the direction of refrig
erant ?ow to said second heat exchanger for
condensation, means for actuating said valve
means, and means to prevent operation of said
actuating means at the start of the refrigera
tion cycle until a pressure di?erential is estab
lished between the high and low pressure sides
of the system.
15
7. In a reversible refrigeration system, a com
pressor, a ?rst heat exchanger, a second heat
exchanger, one of said heat exchangers being
operable as a refrigerant condenser and the
14
10. In a reversible refrigeration system, a com
pressor, a ?rst heat exchanger, a second heat ex
changer, one of said heat exchangers being op
erable as a refrigerant condenser and the other
as a refrigerant evaporator according to the di
rection of operation of the refrigeration cycle, a. '
pair of “three-way” ?ow directing valves, one of
said valves having an inlet connected to the out
let from said compressor and having a pair of
outlets connected one to each of said heat ex
changers, the other of said valves having a pair
of inlets connected one to each of said heat ex
changers and an outlet connected to the inlet to
said compressor, said valves having valve mem
bers having a normal initial position directing
refrigerant ?ow to said ?rst heat exchanger for
condensation and being operable upon actuation
to change the direction of refrigerant flow to said
second heat exchanger for condensation, pressure
other as a refrigerant evaporator according to 20 responsive diaphragms for actuating said valves,
the direction of operation of the refrigeration
a “three-way” valve controlling the supply of
cycle, valve means having a normal initial posi
pressure from the high or the low pressure sides
tion directing refrigerant ?ow to said ?rst heat
of the system to said diaphragms for actuating
exchanger for condensation and being operable
said valves, and means responsive to a pressure
upon actuation to change the direction of refrig 25 differential between the high and the low pressure
erant flow to said second heat exchanger for
sides of the system and controlling the operation
condensation, electrically operable means for
of said “three-way” pressure controlling valve.
actuating said valve means, and a pressure op
erated switch operable to prevent energization
11. In a reversible refrigeration system, a com
pressor, a ?rst heat exchanger, a second heat
of said actuating means at the start of the re 30 exchanger, one of said heat exchangers being
frigeration cycle until a pressure differential is
operable as a refrigerant condenser and the other
established between the high and low pressure
as a refrigerant evaporator according to the di
sides of the system.
\
rection of operation of the refrigeration cycle, a
8. In a reversible refrigeration system, a com
pair of “three-way” ?ow directing valves, one of
35
pressor, a ?rst heat exchanger, a second heat
said valves having an inlet connected to the outlet
exchanger, one of said heat exchangers being
from said compressor and having a pair of outlets
operable as a refrigerant condenser and the
connected one to each of said heat exchangers,
other as a refrigerant evaporator according to
the other of said valves having a, pair of inlets
the direction of operation of the refrigeration
connected one to each of said heat exchangers
cycle, pressure operated valve means having a 40 and an outlet connected to the inlet to said com
normal initial position directing refrigerant flow
pressor, said valves having valve members hav
to said ?rst heat exchanger for condensation
ing a normal initial position directing refrigerant
and being operable upon actuation to change the
?ow to said ?rst heat exchanger for condensation
direction of refrigerant ?oxv to said second heat
and being operable upon actuation to change the
exchanger for condensation, an electrically op 45 direction of refrigerant flow to said second heat
erated pilot valve controlling the supply of pres
exchanger for condensation, pressure responsive
sure for actuating said valve means, and means
diaphragms on said valves and operable upon ap
to prevent operation of said pilot valve at the
plication of pressure from the high pressure side
start of the refrigeration cycle until a pressure
of the system to move said valve members to ef
differential is established between the high and 50 fect said change in direction of refrigerant ?ow,
low pressure sides of the system.
an electric solenoid operated "three-way” valve
9. In a reversible refrigeration system, a com
having inlets connected to the high and the low
pressor, a ?rst heat exchanger, a second heat
exchanger, one of said heat exchangers being
pressure sides of the system and an outlet con
nected for supply of pressure to said diaphragms,
operable as a refrigerant condenser and the
other as a refrigerant evaporator according to
said solenoid valve having a normal initial posi
the direction of operation of the refrigeration
cycle, a pair of “three-way” ?ow directing valves,
pressure side of the system to said diaphragms,
and being operable upon energization to close off
said low pressure connection and to establish a
tion for establishing connection from the low
one of said valves having an inlet connected to
the outlet from said compressor and having a 60 high pressure connection, and a pressure respon
pair of outlets connected one to each of said heat
sive switch connected for response to the differ
exchangers, the other of said valves having a
ential between the high and the low pressure sides
pair of inlets connected one to each of said heat
of the system and having initially open switch
exchangers and an outlet connected to the in
contacts preventing energization of said solenoid
let to said compressor, said valves having valve Go valve at the start of a refrigeration cycle until a members having a normal initial position di
predetermined pressure differential is established
recting refrigerant ?ow to said ?rst heat ex
across the system.
changer for condensation and being operable
12. In a reversible refrigeration system, a com
upon actuation to change the direction of re
pressor, a first heat exchanger, a second heat ex
frigerant flow to said second heat exchanger for
condensation, means for actuating said valves,
and means responsive to a pressure differential
between the high and the low pressure sides
of the system and controlling said valve actuat
ing means. 1
changer, one of said heat exchangers being op
erable as a refrigerant condenser and the other
as a refrigerant evaporator according to the di
rection of operation of the refrigeration cycle, a
pair of “three-way” ?ow directing valves; one of
75 said valves having a casing having two internal
9,858,988
18
‘ walls dividing the same into three chambers, an
inlet opening into the middle chamber of said
valve and connected to the outlet from said com
sure is supplied to the valve inlet adjacent a
closed valve member and refrigerant low side
pressor, said internal walls having valve ports
therein with valve seats facing inwardly of said
pressure is supplied to the valve outlet adjacent
middle chamber, a valve member movable be
tween said valve seats and operable to close one
or the other of said ports so as to direct refrig
erant ?ow through the open port, outlets from the
outer valve chambers connected one to each of
said heat exchangers; the other of said valves
having a casing having two internal walls divid
ing the same into three chambers, said last-named
16
valve connections being such that in both initial
and actuated positions refrigerant high side pres
1,0
a closed valve member thereby establishing a
pressure differential across each closed valve
member for holding the same in valve closed
position, means for actuating said valve, and
means responsive to a pressure di?erential be
tween the high and the low pressure sides of the
system and controlling said valve actuating
means.
-
-
14. In a reversible refrigeration system, a com
internal walls having valve ports therein with
valve seats facing outward into the valve outer 15 pressor, a ?rst heat exchanger, a secondheat ex
changer, one of said heat exchangers being oper
chambers, a pair of valve members one cooperable
able as a refrigerant condenser and the other as
with each of said outward facing valve seats and
a refrigerant evaporator according to the direc
so spaced and interconnected for movement that
tion of operation of the refrigeration cycle, a pair
when one valve member is closing its port the
other port is open, inlets to the valve outer cham 20 of “three-way” flow directing valves; one of said
valves having a casing having two internal walls
bers connected one to each of said heat ex
dividing the same into three chambers, an inlet
opening into the middle chamber of said valve
and connected to the outlet from said compressor,
valve members of said valves having an initial
position directing ?ow of refrigerant to said first 25 said internal walls having valve ports therein with
valve seats facing inwardly of said middle cham
heat exchanger for condensation and being actu
ber, a valve member movable between said valve
able substantially simultaneously to move to an
seats and operable to close one or the other of
actuated position for changing the direction of re
said ports so as to direct refrigerant ?ow through
frigerant flow to said second heat exchanger for
condensation, and said valve connections being 30 the open‘ port, outlets from the outer valve cham
bers connected one to each of said heat exchang
such that in both initial and actuated positions re
ers; the other of said valves having a casing hav
frigerant high side pressure is supplied to the valve
ing two internal walls dividing the same into
' inlet adjacent a closed valve member and refrig
three chambers, said last-named internal walls
erant low side pressure is supplied to the valve
having valve ports therein with valve seats facing‘
outlet adjacent a closed valve member thereby
outward into the valve outer chambers, a pair of
establishing a pressure differential across each
valve members one cooperable with each of said
closed valve member for holding the same in valve
outward facing valve seats and so spaced and in
closed position.
v
changers, an outlet from the valve middle cham
‘ ber connected to the inlet of said compressor; the
, 13. In a reversible refrigeration system, a com
pressor, a ?rst heat exchanger, a second heat ex
changer, one of said heat exchangers being oper
able as a refrigerant condenser and the other as
a refrigerant evaporator according to the direc
tion of operation of the refrigeration cycle, a pair
of “three-way" ?ow directing valves; one of said
valves having a casing having two internal walls
dividing the same into three chambers, an inlet
opening into the middle chamber of said valve
and connected to the outlet from said compressor,
said internal walls having valve ports therein with
valve seats facing inwardly of said middle cham
ber, a valve member movable between said valve
terconnected for movement that when one valve
40 member is closing its port the other port is open,
inlets to the valve outer chambers connected one
to each of said heat exchangers, an outlet from
the valve middle chamber connected to the inlet
of said compressor; the valve members of said
valves having an initial position directing ?ow of
refrigerant to said ?rst heat exchanger for con
densation and being actuable substantially simul
taneously to move to an actuated position for‘
changing the direction of refrigerant ?ow to said
second heat exchanger for condensation, said
valve connections being such that in both initial
and actuated positions refrigerant high side pres
sure is supplied to the valve inlet adjacent a
seats and operable to close one or the other of
closed valve member and refrigerant low side
said ports so as to direct refrigerant ?ow through
the open port, outlets from the outer valve cham 55 pressure is supplied to the valve outlet adjacent
a closed valve member thereby establishing a
bers connected one to each of said heat exchang
pressure differential across each closed valve
ers; the other of said valves having a casing hav
member for holding the same in valve closed
ing two internal walls dividing the same into
three chambers, said last-named internal walls
having valve ports therein with valve seats facing
' outward into the valve outer chambers, a pair of
position, pressure responsive diaphragms on said
valves and operable upon application of pressure
from the high pressure side of the system to move
said valve members to effect said change in di
valve members one cooperable with each of said
rection of refrigerant ?ow, an electric solenoid »
outward facing valve seats and so spaced and in
operated “three-way" valve having inlets connect
terconnected for movement that when one valve
member is closing its port the other port is open, 65 ed to the high and the low pressure sides of the
system and an outlet connected for supply of pres
inlets to the valve outer chambers connected one
sure to said diaphragms, said solenoid valve hav
, to each of said heat exchangers, an outlet from
ing a normal initial position for establishing con
the valve middle chamber connected to the inlet
nection from the low pressure side of the system
of said compressor; the valve members of said
valves having an initial position directing ?ow of 70 to said diaphragms and being operable upon cner
gization to close off said low pressure connection
refrigerant to said ?rst heat exchanger for con
densation and being actuable substantially simul
and to establish a high pressure connection, and
a pressure responsive switch connected for re
taneously to move to an actuated position for
sponse to the di?'erential between the high and
changing the direction of refrigerant flow to said
second heat exchanger for condensation, said
the low pressure sides of the system and having
. 2,668,938
17
‘
initially open switch contacts preventing energi
zation of said solenoid valve at the start of a re
frlgeration cycle until a predetermined pressure
differential is established across the system.
15. The combination with a reversible refriger
ation system having a compressor, two heat ex
changers either of which may function as a con
denser or an evaporator, and two pressure oper
ated “three-way” valves for determining to which
heat exchanger refrigerant may ?ow for con
densation; of an electric solenoid operated pilot
valve comprising a valve casing enclosing a
18
operable to close oif flow through one inlet and
to permit flow through the other inlet, a lever
fulcrumed in said casing and engaging said valve
member for moving the same, the free end of
said lever having a normal initial position slant
ing downward and holding said valve member
closing said upper inlet port, an outlet port
through the end wall of said casing adjacent the
free end of said lever, said casing having an
aperture in its upper wall adjacent the free end
of said lever, a solenoid coil having a plunger
and secured at one end in said last-named aper
chamber, alined inlet ports in the top and bot
tom walls of said casing each having a valve seat,
a valve member movable vertically between said
valve seats and having valve end portions co
ture, said solenoid plunger having an end por
tion engageable with said lever, said plunger end
portion having a groove providing upper and
lower spaced shoulders, said plunger upper shoul
operable one with each of said valve seats and
operable to close off flow through one inlet and
to permit ?ow through the other inlet, a lever
der resting on the free end of said lever when
in a down position so that said valve member
is held closed by the weight of the plunger, a
fulcrumed in said casing and engaging said valve 20 bracket member in said casing adjacent the pivot
member for moving the same, the free end of
point of said lever, an overtravel spring com
said lever having a normal initial position slant
pressively positioned between said bracket and,
ing downward and holding said valve member
said lever and substantially on center when said
closing said upper inlet port, an outlet port
lever is in a down position, said plunger being
through the end Wall of said casing adjacent the 25 operable upon energization of said solenoid coil
free end of said lever, said casing having an
to move upward and to cause said lower shoulder
aperture in its upper wall adjacent the free end
to strike said lever end with an impact to move
of said lever, a solenoid‘ coil having a plunger
said spring overcenter for actuating said lever,
and secured at one end in said last-named aper
said spring being operable upon movement over
ture, said solenoid plunger having an end por 30 center to move said lever to an up position and
tion engageable with said lever, said plunger
said valve member to a down position, said spring
end portion having a groove providing upper and
holding said lever up with a force substantially
lower spaced shoulders, said plunger upper
equal to the weight of said plunger, said lever
shoulder resting on the free end of said lever
and said plunger coming to rest in up positions
when in a down position so that said valve mem~ 35 such that the free end of said lever is inter
her is held closed by the Weight of the plunger,
mediate said shoulders, said plunger being oper
a bracket member in said casing adjacent the
able upon deenergization of said coil to strike said
pivot point of said lever, an overtravel spring
lever with an impact which together with the
compressively positioned between said bracket
plunger’s weight is su?icient to overcome the
and said lever and substantially on center when 40 force of said spring and return the lever to a
said lever is in a down position, said plunger
down position, said inlet ports being connected
being operable upon energization of said solenoid
to the high and the low pressure sides of the
coil to move upward and to cause said lower
I system, said outlet port being connected to said
shoulder to strike said lever end with an im
“three-way” valves for supplying an actuating
pact to move said spring overcenter for actuat
pressure thereto, and a pressure repsonsive
ing said lever, said spring being operable upon
switch responsive to the establishment of a pres
movement overcenter to move said lever to an
sure differential across the system and control
up position and said valve member to a down
ling the energization of said solenoid coil.
position, said spring holding said lever up with
a force substantially equal to the weight of said r
plunger, said lever and said plunger coming to
rest in up positions such that the free end of
said lever is intermediate said shoulders, said
plunger being operable upon deenergization of
17. An electric solenoid operated pilot valve
comprising a valve casing enclosing a chamber,
alined inlet ports in the top and bottom walls of
said casing each having a valve seat, a valve
member movable vertically between said valve
seats and having valve end portions cooperable
said coil to strike said lever end with an impact
one with each of said valve seats and operable‘to
close oil ?ow through one inlet and to permit flow
cient to overcome the force of said spring and
through the other inlet, a lever fulcrumed in
return the lever to a down position, said inlet
said casing and engaging said valve member for
ports being connected to the high and the low
moving the same, the free end of said lever having
pressure sides of the system, and said outlet port 60 a normal initial position slanting downward and
being connected to said “three-way” valves for
holding said valve member closing said upper
supplying an actuating pressure thereto.
inlet port, an outlet port through the end wall of
16. The combination with a reversible re
said casing adjacent the free end of said lever,
frigeration system having a compressor, two heat
said casing having an aperture in its upper wall
exchangers either of which may function as a
adjacent the free end of said lever, a solenoid coil
condenser or an evaporator, and two pressure
having a plunger and secured at one end in said
which together with the plunger’s weight is suffi
operated “three-way” valves for determining to
last-named aperture, said solenoid plunger hav
which heat exchanger refrigerant may ?ow for
ing an end portion engageable with said
condensation; of an electric solenoid operated
lever, said plunger end portion having a groove
pilot valve comprising a valve casing enclosing 70 providing upper and lower spaced shoulders,
a chamber, alined inlet ports in the top and bot
said plunger upper shoulder resting on the
tom walls of said casing each having a valve
free end of said lever when in a down posi
seat, a valve member movable vertically between
tion so that said valve member is held closed by
said valve seats and having valve end portions
the weight of the plunger, a bracket member in
cooperable one with each of said valve seats and 75 said casing adjacent the pivot point of said lever.
2,658,988 }
19
direction of operation of the refrigeration cycle,
an overtravel spring compressively positioned be
tween said bracket and said lever and substan
tially on center when said lever is in a down posi
?rst and second “three-way" ?ow directing valves
controlling the direction of operation of the
tion, said plunger being operable upon energi
refrigeration cycle; said ?rst valve having a cas
ing having one central inlet and two end outlets,
zation of said solenoid coil to move upward and to
cause said lower shoulder to strike said lever end
said casing having two internal walls separating
with an impact to move said spring overcenter _
said inlet and said outlets and dividing the cas-i
for actuating said lever, said spring being oper
ing into three chambers, said walls having valve
a down position, said spring holding said lever up
with a force substantially equal to the weight of
said plunger, said lever and said plunger coming
to rest in up positions such that the free end of
said lever is intermediate said shoulders, and 15
member movable between said valve seats to
control the direction of out?ow from said valve
and carried by a valve stem which ‘projects
through one of said ports into one of the end
valvechambers, a pressure responsive diaphragm
closing one end of said one chamber and opera
tively connected to said stem for moving said
ports therethrough with valve seats facing in
able upon movement overcenter to move said
lever to an up position and said valve member to 10 wardly of the middle valve chamber, a valve
said plunger being operable upon deenergization
of said coil to strike said lever end with an impact '
which together with the plunger’s weight is suf-'
?cient to overcome the force of said spring and
' valve member, a cover member closing said one
tion of operation of the refrigeration cycle, ?rst
and second “three-way” ?ow directing valves
valve chamber to one end of said second heat
exchanger, a conduit connecting the outlet from
end of said one valve chamber and enclosing with
return the lever to a down position.
20 said diaphragm a space for receiving a valve
actuating pressure, a spring operatively engaging
18. In a reversible refrigeration system, a com
said valve member and urging the same to close
pressor, a ?rst heat exchanger, a second heat ex
said one valve port, a conduit connecting the
changer, one of said heat exchangers being oper
outlet from said compressor to said valve inlet,
able as a refrigerant-condenser and the other as
a refrigerant evaporator according to the direc 25 a conduit connecting the outlet from said one
the other of said valve chambers to one end of
controlling the direction of operation of the re
said ?rst heat exchanger; said second valve hav
frigeration cycle, said ?rst valve having one inlet
and two outlets, said second valvehaving two in 30 ing a casing having two internal walls dividing
it into three chambers, two inlets one to each
‘ lets and one outlet, a refrigerant receiver having
of the end chambers and an outlet from the
an inlet and an outlet, pressure responsive means
middle of said chambers, said internal walls hav
controlling the operation of said “three-way"
ing valve ports therethrough with outwardly fac
'valves, a “three-way” electric solenoid pilot valve
having two inlets and one outlet, a pressure re 35 ing valve seats, a pair of valve members one in
each end chamber interconnected for movement
sponsive switch controlling said solenoid valve
and spaced so that when one is closed the other
and having high and low pressure inlets, a con
is open, a valve stem supporting said valve mem
duit connecting the outlet of said compressor to
bers and extending through both of said ports
the inlet of said ?rst-“three-way” valve, 9, con
duit connecting one of the outlets of said ?rst 40 and into one of said end chambers, a pressure
responsive diaphragm closing one end of said
valve to one end of said ?rst heat exchanger, a
one chamber and operatively connected to said
conduit connecting the other outlet of said ?rst
stem for moving said valve members, a cover
valve to one end of said second heat exchanger, :1.
member closing said one end of said one cham
‘ conduit connecting the other end of said ?rst
heat exchanger to one of the inlets to said second 45 ber and enclosing with said diaphragm a space
for receiving a valve actuating pressure, a spring
valve, a conduit connecting the other end of said
operatively engaging one of said valve members
second heat exchanger to the other inlet to said
and urging the valve member in the other end
second valve, a return conduit connecting the
chamber toward closed position, a conduit con
outlet of said second valve, to the inlet to said
necting the inlet to said one chamber ‘to the
compressor, two conduits connecting said one
other end of said second heat exchanger, a con
ends of said ?rst and second heat exchangers re
‘duit connecting the inlet to said other end cham
spectively to the outlet from said receiver, each of
ber to the other end of said ?rst heat exchanger,
said last-named conduits having positioned ,
a conduit connecting the outlet from said middle
therein adjacent its respective heat exchanger
an expansion valve of the type which requires a 55 chamber to the inlet to said compressor; a re
frigerant receiver having an inlet and an outlet,
reduction of pressure at its outlet to a predeter
two conduits connecting the other ends of said
mined low value to open, two conduits connecting
heat exchangers to the ‘inlet of said receiver,
said other ends of said ?rst and second heat ex
changers respectively to the inlet to said receiver,
- check valves one in each of said last-named
each of said last-named conduits having a check 60 conduits and opening in the direction of ?ow
toward said receiver, two conduits connecting
valve therein which opens upon ?ow toward said
said one ends of said heat exchangers to the
receiver, conduits connecting the inlet side of
said receiver and the compressor return conduit , outlet from said receiver, expansion valves one
in each of said last-named conduits and con
respectively to the inlets of said pilot valve, a con
duit connecting the outlet of said pilot valve to
said pressure responsive means, and conduits
connecting the inlet side of said receiver and said
compressor return conduit to the high and the
low pressure inlets respectively of said pressure
responsive switch.
'
19. In a reversible refrigeration system, a com
pressor, a ?rst heat exchanger, a second heat
exchanger, one of said heat exchangers being
operable as a refrigerant condenser and the other
as a refrigerant evaporator according to the
trolling refrigerant ?ow therethrough, said ex
pansion valves being of the thermostatic type
and having pressure responsive means determin
ing a predetermined maximum operating pres‘
sure, a‘ “three-way” solenoid pivot valve con
70 trolling the application of pressure to said valve
actuating diaphragms and having two inlets andv
one outlet, a conduit connecting said pilot valve
outlet to the space enclosed adjacent said valve
,actuating diaphragms, conduits connecting said
75 pilot valve inlets to the inlet of said receiver,
9,558,988
and to the suction side of said compressor, a
pressure differential switch controlling energiza:
tion of said pilot valve and having high and low'
pressure inlets, and conduits connecting said high
pressure inlet to the inlet of said receiver and
said low pressure inlet to the suction side of
said compressor.
-
said valves having an inlet connected to the outlet
from said compressor and having a pair of outlets
connected one to each of said heat exchangers.
the other of said valves having a pair of inlets
connected one to each of said heat exchangers
and an outlet connected to the inlet to said com
pressor, said valves having valve members hav
ing a normal initial position directing refrigerant
pressor, a ?rst heat exchanger, a second heat
?ow to said first heat exchanger for condensation
exchanger, one of said heat exchangers being 10 and
being operable upon actuation to change
operable as arefrigerant condenser and the other
the direction of refrigerant ?ow to said second
as a refrigerant evaporator according to the
heat exchanger for condensation, pressure re
direction of operation of the refrigeration cycle,
sponsive diaphragms on said valves and operable
a pair of “three-way" ?ow directing valves, one
upon application of pressure from the high pres
of said valves having an inlet connected to the 15 sure side of the system to move said valve mem
outlet from said compressor and having a pair
bers to effect said change in direction of refriger
20. In a‘reversible refrigeration system, a com
of outlets connected one to each of said heat
ant ?ow, an electric solenoid operated “three- exchangers, the other of said valves having a
way” valve having ‘inlets connected to the high
pair of inlets connected one to each of said heat
and the low pressure sides of the system and
exchangers and an outlet connected to the inlet 20
an outlet connected for supply of pressure to
to said compressor, said valves having valve
members having a normal initial position direct
ing refrigerant ?ow to said ?rst heat exchanger
for condensation and being operable upon actua
tion to change the direction of refrigerant flow 25
to said second heat exchanger for condensation,
pressure responsive diaphragms for actuating
said valves, and a “three-way” valve controlling
the supply of pressure from the high or the low,
pressure sides of the system to said diaphragms 30
for actuating said valves.
said diaphragms, said solenoid valve having a
normal initial position for ‘establishing connec
tion from the low pressure side of the system
to said diaphragms, and being operable upon
energization to close 01! said low pressure connec
tion and to establish a high pressure connection.
EARNEST J. DILLMLAN.
THOMAS E. NOAKES.
.
21. In a reversible refrigeration system, a com
pressor, a ?rst heat exchanger, a second heat
exchanger, one of said heat exchangers being
operable as a refrigerant condenser and the other 35
as a refrigerant evaporator according to the
direction of operation of the refrigeration cycle,
a pair of “three-way" ?ow directing valves. one of ~
REFERENCES CITED
The following references are of record in the
file of this patent:
UNITED STATES PATEN'i‘S
Number
Name
2,135,285
2,148,415
Date
Gibson ____________ __ Nov. 1, 1938
'
Labberton ________ __ Feb. 21, 1939
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