close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2139411

код для вставки
Patented Dec. 6, 1938
2,139,411
UNITED STATES PATENT OFFICE
2,139,411
PRESSURE REGULATOR
Irving C. Jennings, South Norwalk, Conn.
Application May 29, 1935, Serial No. 24,139
3 Claims.
The object of thisl invention is to improve the
operationl of the electric switch, which is used in
connection with the diaphragm of a vacuum or
pressure regulator. Inv such an apparatus, the
5 actuating fluid operates on the surface of a
spring or weight pressed diaphragm which is
connected to the switch, and the parts are ar
ranged so that when certain pressures or vacu
ums are reached, the switch will be thrown to
cut the operating means, usually an electrically
driven pump, out of and into operation.
An electrical switch'must open with a snap
action to prevent arcing and for this purpose
the switch is usually provided with a mechani
15 cally acting snap or tip over mechanism. In
using such a vacuum pressure regulator, I havel
experienced a great deal of di?liculty in getting
a closely adjusted operation.
"
For instance, in using an ordinary.` vacuum
20 pressure regulator to maintain a Vacuu‘rn of be
tween twenty-one and twenty-two inches, which
is a desirable point for vacuum steam heating, I
have found that the pump should be stopped and
started at about one-half inch above and one
25 half inch below an average of twenty-one and
one-half inches, or within a range of one inch>
of mercury. ' With the old arrangement, the finest
range of adjustment possible was three inches
of mercury and, therefore, it was necessary to
30 have the pump start in operation at twenty-one
inches and to cut out, to pull a vacuum up
to twenty-four inches, which with hot returns
often caused the pump to run all the time.
I discovered that this diiiiculty can be over
35 come by removing~the mechanical snap action
switch from an ordinary vacuum pressure regu
lator and-by substituting therefor a single tilt
ing mercury switch operated from the diaphragm
and> adjusted so that the drag of the mercury
40 against the electrode or electrodes, as well as
the friction of the mercury in its containing ture,
will cause a delayed action, which will effect a
small but actual diiïerence in pressure between
the on and oiî positions of the switch and which
4 Ul will cause the switch to open with a snap action.
With this arrangement I can easily control the
on and on” positions of the switch within the
range of an inch of mercury.
One embodiment of the invention is illustrated
in the accompanying sheet of drawings, in
which:
Fig. l is a sectional plan view of the improved
apparatus.
.
Fig. 2 is a central sectional elevation, and
(Cl. 200-83) _
Figs. 3 and 4 are partial sectional elevation
to illustrate the peculiar action.
'
Referring to the drawing and in detail,' I0
designates a bottom plate, and II a cover plate,
a diaphragm I2 being secured between IU and 5
II, andv these parts being held together by
screws I3.
The actuating fluid is permitted to operate
on the upper side of the diaphragm I2 through
a coupling III) on the upper or cover plate Ii, 10
to which coupling a pipe can be connected.
Where the switch is to be used asa pressure
regulator, the actuating iluid is admitted to act
on the lower side of the diaphragm through a
coupling IDG, illustrated in dotted lines in Fig. 16
2, attached to the plate I0, the large- vent open
ing in which is then closed.
Upper and lower plates I5 and I4 are placed
on the sides of the diaphragm I2 and held there
to by a screw I6 threadedinto a nut I1.
A
supplemental diaphragm I8 is placed on top of
the cover plate vII and held in position thereon
by a packing ring I9, a plate 22, and screws 2i,
threaded into the plate 22.
A supplemental contact 23 having a pin 24
bears on the supplemental diaphragm I8 and
through the same on the large nut I1.
An inverted U--shaped bracket 25 is held on
the base 22 by screws 26. An operating spring
21 is housed in the bracket 25, the lower end of 30
the spring being contained in a thrust block or
cup 28 in which the pin 24 is fitted. A screw 29
extends down inside of the spring 21, the screw
head being fitted in the top of the bracket 25
and having an integral collar 30 bearing against
said bracket. The spring 2'I bears on a nut 32
threaded on the screw 29 so that by turning the
screw the pressure of the spring can be adjusted.
A tilting plate 33 is pivoted by screws 34 to
the sides of the bracket 25. The thrust block 28 40
is provided with arms 35 which are connected
lby screws 36 to tilting plate 33. One side of the
tilting plate 33 is extended, as at 31, and is pro
vided with' a screw 38 having a check nut 39, the
screw being set in position to engage the head of
a pin 40 sli-ding in a bracket 3I on plate 22, a
spring 4I being arranged on the pin 40.
lWhen the screw 38 is backed "away so that it
can never come in contact with the plate 40
throughout the travel of the extension arm 31, 50
the switch will open and close with aminimum
diiïerence in pressure.
By adjusting the screw 38 so that it comes in
contact with the plate 40 through a portion of
the travel of the extension arm 31, the switch 55.
2
2,139,411
may be adjusted to open and close with a greater
diiferential in pressure.
The tilting plate 33 is provided with an arm 42
carrying a clamp 43 held thereto by screw 44.
A mercury switch 45 is secured in said clamp
43. This mercury switch consists of a tube from
which the air is exhausted and a globule of mer-`
cury M. One`or more electrodes 48 and 41 is
or are sealed into the tube of the mercury switch
45 and suitable lead in wires 48 and 49 are con
nected thereto.
The parts` as thus far described can be adjusted
to get a very delicate operation with the switch.
Assuming> that the device is used as a vacuum
15 pressure regulator, under the ñgures previously
described, when the switch is closed- the same
will be in the position shown in Fig. 2. As the
vacuum on top of the diaphragm I2 is increased,
the atmospheric air pressure on the under side
20 of said diaphragm will tilt the left hand> end of
the mercury switch 45 to its critical position,v as
shown in Fig. 3. In this position the globule
of mercury M will tend to run or flow to the right,
but will be held from so doing by the relud ance
25 of the mercury to move past the electrode or elec
trodes.
As the vacuum now slightly increases, the
tendency of the mercury to flow by gravity‘to the
right will overcome this resistance to iiow, and
30 the mercury switch will move to its open posi
tion, as shown> in Fig. 4.
Thus there will be a snap action of the parts
between the position shown in Figs. 3 and 4.
which is measured by the said retarding effect
35 of the mercury. This factor of resistance to dow
can be made much less than the extra pressure
necessary to obtain the throw of the switch to
overcome
any
mechanical
snap
mechanism.
Therefore, the mechanism described provides a
40 snap switch which can be very delicately ad
justed.
I am aware that itis common to tilt a mer
cury switch by a fluid acting on a diaphragm,
corrugated bellows or piston, but so i'ar as I am
„ aware, the resistance to flow of a globule of mer
cury has never been employed as the sole means
of providing for the necessary snap action.
,The details and arrangements herein described
may be greatly varied by a skilled mechanic
without departing from the scope of my inven
50 tion as expressed in the appended claims.
Having thus fully described my invention, what
I claim and desire to secure by Letters Patent
is:
,1. A pressure regulator comprising a dia
phragm on the surface of which an actuating
fluid operates, adjusting means for determining
the pressure at which said diaphragm operates,
and a tilting mercury switch mounted for move
ment under the influence of said diaphragm,
means to cushion movement'of said switch, said
mercury switch having an electrode positioned 10
at a substantial angle to and in the path of flow
of the mercury and positioned to offer an ob
struction to such flow of mercury whereby ad
hes'on of the mercury to the electrode will in it
self cause a delayed action of the switch followed
by an actuation of the switch with a snap action.
2. A pressure regulator comprising a dia
phragm on the surface of which an actuating
ñuid operates, adjusting means for determining
the pressure at which said diaphragm operates, 20
a tilting plate connected to said diaphragm for
direct actuation thereby, adjustable means to
cushion downward movement of said tilting plate,
and a tilting mercury switch mounted on said
plate for movement therewith, said mercury 25
switch having an electrode positioned at a sub- '
stantial angle to and in the path of flow of the
mercury and positioned to oiîer an obstruction
to such flow of mercury whereby adherence of
the mercury to the electrode will in itself cause 30
a delayed action of the switch followed by an
actuation ofI the switch with a snap action.
3. A pressure regulator comprising a dia
phragm on the surface of which an actuating
ñuid operates, adjusting means for determining 35
the pressure at which said diaphragm operates,
a tilting plate fulcrumed upon said diaphragm
for direct actuation thereby, adjustable means
located at one side of the fulcrum to cushion
downward movement of said tilting plate, and a 40
tilting mercury switch mounted on said plate at
the opposite side of said fulcrum for movement
with the plate, said mercury switch having an
electrode positioned at a substantial angle to and
in the path of iiow of the mercury and positioned 45
to offer an obstruction to such flow of mercury
whereby adherence of the mercury to the elec
trode will in itself cause a delayed action of the
switch followed by an actuation of the switch
with a snap action.
.
IRVING C. JENNINGS
50
Документ
Категория
Без категории
Просмотров
0
Размер файла
318 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа