вход по аккаунту


Патент USA US2501432

код для вставки
March 21, 1950
Filed Dec. ‘18, 1944
4 Sheets-Sheet 1
James H B 00th
March 21, 1950
Filed Dec. 18, 1944
4 Sheets-Sheet 2
Jame; H1300 Zfh
Mangh 2N1‘), }950
Filed Dec. 18, 1944
4 Sheets-Sheet-4
Patented Mar. 21, 1950
James H. Booth, Detroit, Mich., assignor to
Thompson Products, Inc., Cleveland, Ohio, a
corporation of Ohio
Application December 18, 1944, Serial No. 568,605
2 Claims. (Cl. 170-16031)
vide a propeller pitch-changing device embodying
This invention relates to an inexpensive device
for adjusting members, such as blades, and spe
ci?cally relates to an easily installed propeller
a cam member actuated into and out of operat
ing position by the pilot of the plane and, when
in operating position, causing a pump rotatable
pitch adjusting device.
The invention provides a small compact as
sembly, rotatable with a propeller hub, for
changing the pitch of propeller blades that are
rotatably mounted in the hub. The assembly in
cludes ?uid pressure-operated means acting on
the blades to rotate them in their mountings. l0
Fluid pressure for actuating these means is
created by a pump. The pump is actuated by a
non-rotatable cam, and this cam is manually
with the propeller to produce hydraulic pressures
for overcoming aero-dynamic forces on the pro
peller blades to change the pitch of the blades.
Another object of this invention is to pro
vide a propeller pitch-changing device having a
pump actuated by a cam and a ?uid ?ow control
valve actuated by another cam to operate
plungers for moving propeller blades about their
radial axes.
Other and further objects of the invention will
ating position.
15 be apparent to those skilled in the art from the
following detailed description of the annexed
According to this invention, the blades of a
sheets of drawings which, by way of preferred
propeller are mounted for rotation in a propeller
actuated by the pilot into and out of pump-oper
example, illustrates one embodiment of the in
hub in such a manner that the aerodynamic force
on the blades in operation tends to move them
On the drawings:
into high pitch. The device of this invention is 20
Figure l is a plan view of a propeller mount
contained in the hub of the propeller and, when
the cam is moved into position for actuating the ‘ ing according to this invention embodying a pro
peller pitch changing device according to this
pump of the device which rotates with the pro
peller hub, the hydraulic pressure generated by
the pump will move the blades into low pitch 25
against this aero-dynamic force.
In order to cause the aero-dynamic forces on
Figure 2 is a front ‘end elevational view of the ‘
mounting shown in Figure 1 with parts of the
propeller blades omitted.
Figure 3 is a cross-sectional view taken along
the operating blades to urge the blades into high
the line III-III of Figure 1.
pitch, the blades are tilted back from their radial
Figure 4 is a cross-sectional view taken along
rotating axes to move their centers of gravity
the line IV--IV of Figure 1.
toward their centers of ‘radial rotation to lessen
Figure 5 is a cross-sectional view taken along
or negative the centrifugal torsion eiiect tend
the line V—-V of Figure 2.
ing to rotate the blade into low pitch and the
Figure 6 is a cross-sectional view taken along
blades are designed to have their centers of pres
sure to the front of the centers of radial rotation. 35 the line VI-VI of Figure 5.
Figure '7 is a cross-sectional view taken along
While aero-dynamic force alone can be relied
the line VII-VII of Figure 4.
upon to urge the blades into high pitch, it should
Figure 8 is a plan view taken along the line
be understood that this force can be augmented
VIII—~VIII of Figure 7.
by springs, weights, or the like.
Figure 9 is a cross-sectional view taken along
A feature of this invention resides in the pro~ 40
the line IX—-IX of Figure 8.
vision of a compact hydraulic pressure-operated
Figure 10 is a cross-sectional view taken along
propeller pitch-changing device that can be‘
the line X—X of Figure 8.
readily installed on standard airplane engine
Figure 11 is a cross-sectional view taken along
Another feature of the invention resides in the 45 the line XI—XI of Figure 8.
Figure 12 is a fragmentary cross—sectional view
provision of a self-contained unit in a propeller
taken along the line XII—XII of Figure 13.
hub for changing the pitch‘of blades rotatably
Figure 13 is a plan view of the ring block taken
mounted in the hub.
along the line XIII-XIII of Figure 5.
Another object of this invention is to provide
a hydraulically-operated propeller pitch changer 50 Figure 14 is a plan view of the cover plate for
the ring block taken along the line XIV-XIV of
utilizing only minute quantities of oil or other
hydraulic ?uid.
Figure 5.
Figure 15 is a developed diagrammatic view il
lustrating the operation of the ?uid pressure ac
a device which adjusts the positions of rotating
blades in accordance with the manually adjusted 55 tuated parts of the device of this invention.
As shown on the drawings:
position of a non-rotatable member.
As best shown in Figures 1 and 5, the device
A still further object of the invention is to pro
of this invention includes a mounting plate II]
vide a propeller pitch-adjusting device wherein
for operatively attaching certain parts of the de
a stationary cam actuates a pump for producing
vice to an airplane engine I I. The engine H has
pressure to change the pitch of propeller blades.
upper and lower boss portions Ha. Brackets l2,
A still further object of the invention is to pro
v A further object of the invention is to provide
I 82 carried by the mounting plate ‘It straddle each ‘
mounted about longitudinal or radialaxes such
as‘A‘illustrated in Figure‘ "1, for‘changin‘g the pitch
boss portion ‘lid and ‘a ‘connecting pin or lug l3
secures the brackets to ‘the bosses. The'ni'ou‘nt;
ing plate I!) has a cylindrical collar portion illld
'of the blades; As explained above,v each blade is
7 so tilted with respect to its axis of radial rotation
projecting forwardly from the front end of the
engine ll and this collar portion vIlla slidably re
A to negative centrifugal torsion effect tending
‘to, rotate‘ the blade into low pitch and has the
ceives a control member Mhaving a cylindrical
center P of pressure on the blade forwardly from
side wall in engagement with the ~collar portion
this axis Also that aerodynamic forces on the
Illa and equipped with several ‘sloping slots H5 at
blade tend to rotate it into high pitch.
spaced intervals therearound as best shown in 10
The retainers "26 ‘for the blades B have tail por
Figures 3 and 7. These slotsv 15 receive theheads
MODSZBUBXtél’ldiYlgilltO the casing 2i. These tail
16a of bolts 16 which are passed through thick
‘portions 261) carry laterally projecting pins 30 and
ened portions of the collar Illa and secured to ‘the
'3! in ri'ght'angular relation. The pins 3i project
collar by means of nuts I‘! as best shown in
into ‘slots Zld ofthe rear Wall 25b of the hub
Figure .3.
15 casih‘g'N, as nest'snow'n in Fi'gur‘es'zl and '5. ‘Set
The collar lll'a-h'as ‘an elongated slot ‘lob there"
in and an arm 'l-‘B secured on the control member
screws 32 are threaded into the Wall 2 to to ‘pro
je‘ct ‘into opposite sides ‘of the‘slots "21d and rorim
l4 extends through the "slot lilb ‘to receive a clevis
abutments for the pins 31 ‘thereby limiting the
l9 on the end ‘of a control rod, an operating
va'n‘io'u'nt‘of rotation of the blades 13 ‘about the ‘axes
Bowden wire or the like ‘20. The control rod ‘2t 20 of radial rotation A. ‘These‘setfscre‘ws 32 can be
passes through an aperture in the mounting
"adjusted so that'the'amo'uiit or radial ‘rotation of
plate lilo, as'shown in Figure‘S, and is directed to
the blade "can be ‘controlled to any “desired 'de
the'cock'pit or the airplane where it cah'be ‘easily
reached ‘for manual actuation by the‘ pilot. Move
‘gre'e. Likewise? the ‘screws can ‘be. adiusteuso
‘merit of 'the control rod!!! will swing the arm
18 to rotate‘ the control member ill in the collar
portion l?d. However, since the heads ltd pro
tions‘for the blades can ‘Ibeobta‘in'e'd‘since the
that the desired high ‘pitch and low pitch p'o'si
setting "of screws 3‘21‘on ‘one side ‘of ‘the ‘pins 3|
will determine the high vpitch positions for‘the
blades '33 while the setting of‘i‘scre'ws
on the
other side of the pins 3i will determi'iie‘the low
j'ect into the ungousisiots ihof the control ‘mem~
ber 14, any ro'tati'onfoi the "control member will
slide it axially relative 'lto'jth'e collar the.
‘Thelcontrol member
pitch positions 'forthe‘blade's. 'lruesirédsprings
an'e‘nd face with 'a ‘
(notshow'h)v can be vus'ed‘to act "on the pins}?!
‘for'urging ‘the ‘blades vto rotate into high pitch
cam track Hid tliereo'n'ali'd "a ‘flat surface Mb
surrounding the cam track Ma.
positions, thereby assisting'thefareodyriarnic force
As shown in Figures 1, 5 aridj'ka propeller hub
casing 2i ha'sfa‘ rear end portion freely’e'mbrac
are ‘the sonar portion ‘ii-toot the ijnounting ‘ii>la"te
ill. This ‘casing 21 has y'dialhetri'cally opposed
'Which'lnaintairls vthe‘blades
(Figure 4) connect the 'shaft'and hub portion ‘tic ‘
A nut 22 is threaded
the front é‘nd‘ offline
shaft'S‘to ‘thrust'a'gainstthetno of the "portion
back wall'2lb of ‘the'hu‘b 121-.
Ho and hold it on the shaft. “Thisnut is locked
'_ v_
tom'or ‘the'ring block by me’ans‘io'f"boltsblichas
As best shown in Figure 12, the rin‘g‘7bl'ock' 35
carries an‘o’il't'ankor casing '41 vvi‘nYan“aperture
thereof, and “this‘l'ca's’in‘g "4i lpro’jec'ts 'beyond"3the
The blades 13 have their inner ends‘ secured'i‘n
tapered "skirt portions “2576a or retaiiier ‘members’ 26
bottom cover '39 into‘th'e sp'ace‘be'tween the bot
tom cover and the end‘ wall 21b "of the'hub’2l. ' ‘A
which are rotatably mounted ‘on ball bearings"?!
plunger "42 vis 'sl'id'ably ‘mounted in the casing, 4|
in the'soeket no or the hub'c'as'i'ng. Nutses
and this ‘plunger ?fzjhas a head H'Za‘at'oiie'end
thereof ‘slidably engagihgthe ‘walls ‘ofi'the ‘casing,
'ithreadedbn the socket'sv‘il a thrust against the
outer‘race rings of the ballbearings 2'1‘ to retain
these outer raceriiresiin ‘the socket. The ball
together with a ‘reducedTdiameter‘“hollow vshank
portion ‘42b projecting ‘towardth-e other‘je'nd of
the casing in ‘spacedfrela'tion‘inward from‘ the
'df ‘the bearings ‘retain the :i'n’lfle'r race rings ‘in
casii'rg wall. "The head f42'agh‘as vents E3 ‘ ere‘
positionof al’l'd‘va
the retaine'r'h-l'e'inberl?
'lo'ckihg' ring 29 thrusts
an inner-race ring of‘ one of ‘the bearing assem
'lo'lie's so that they retainer cannot move ‘axially
relative to the-‘socket tidy However, the retainer
‘can rotatexfreelylwithIthefinner race rings 'ofpthe
ball bearings ‘2i. The blade‘s'B"are'thus‘rotatably
v the ‘block. a bo'ttom‘c'over'39 is held on the‘b'ot
A_ streamlined nose casing 524 is ‘secured onfthe
front end or the hub'ca‘sin‘g ‘12Tby means of ‘screws
25‘or the like for covei‘ihg'th'e ‘open front of ‘the
A top cover platev '31 held ‘on "the ring'block
by means 'of‘cap screws such as v38threaded into or
shoulder 35b ‘is provided at the bottom or ‘the
aperture ‘35a .to thrust against vthe end'of the
hub portion ‘2 In‘. A'second aperture-tee extends
inwardly from the other end'of thefring‘block 35
to receive the nut '22 freely therein ‘and this aper
ture v35c has a Shoulder 35d? at the bottom ‘there
of bottoming a flange‘ 22a’of the nut. ‘The ring
block 35 is thus securedfto’thehlib 21c. Inad
ditioh, however, ‘bolts such ‘as 1'36 ‘are passed
through therrin‘g ‘block and threaded into ‘the
' for corotat'ion.
or to receive ‘the end’o'f "the ‘hub'portion'2lc. A
end ofengin'e ii. The ‘ehgl-n'e shaft s‘ is‘ prer
erably tapered to receive th'e'hub portionT'?ic ‘in
Wedgin'g r'e‘latioh'shibl‘ah‘d keyiheahs 'su’chfas K
of the vshaft.
As bestinshown
the hub‘ba'Sing'Z'I
in ,Figure‘5,'aand
blockv 3'5
aperture 35a extending‘ r‘o'ijn one end face ‘there
chored in the nut and "hollow'skirt-like end ‘S’
high pitch posi
locking ‘the same inadjusteu ‘position. I
The hub casing 2!, as best shown in Figure 5.,
has a back wall 12'! b‘ 's'p‘ae‘edin' front of the'i'n’ount
ingplate H] and extending‘ radially inward'tjo a
centralihoss Or hub ‘portion zicjwhic‘h is ‘mounted
on the engine shaft S; proi
from ‘the front
la’g'a'ihst rotation by means ofj‘pins' ‘such as
Nuts '33 can be provided on the set sc‘rews‘i32 for
laterally projecting cylindrical socket or sleeve
‘portions f2la which receive ‘the inner ends of‘pro
peller'blades B.
through connecting ‘th‘e‘sp'aceiin' the‘ tank‘b'etw'éeh
the'liead and end 'wall'of the'ntahkwith thev space
in trie'ta’nls‘ surrounding the shank 2:211. v_-A"fsea'1
44 is "carried by the sharia-42oandjslidabiy en'
gages 'the‘wa'llwof the tam; in‘fs'e‘alin'g ‘relation
75 therewith. ' 'A "Coil "Spring ‘45”is‘ Contained"ih"the
shank 42b to urge the plunger 42 toward the
the block 60 symmetrically around the central
closed end of the tank. A plug 46 is threaded into
dumbbell valve 62 as illustrated in Figures 8 to
11. As shown in Figures 9, 14 and 15, the cover
‘aisle cover plate 31 for bottoming the coil spring
Oil or other hydraulic ?uid in the tank 4| is
plate 31 has a groove therein providing a passage
way 66 to the valve seat 10 of the ?rst valve as
sembly. A ball 1| is pressed by a spring 12 to
thus always maintained under spring pressure, so
seat against the seat 16. Fluid under pressure of
that air can never be delivered to the system in
the event of leakage of oil. For example, as oil
the pump is suf?cient to unseat the ball 1| so
might leak out of the system, or contract due to
that the ?uid can flow through the passageway 13
temperature changes, the spring 45 will urge the 10 into anothmer groove 14 in the cover 31‘. This
plunger member 42 down toward the closed bot
groove 14 has communication with the seat 15 of
tom of the tank for decreasing the size of the
the second valve assembly, with the pump cham
ber of pump assembly 41, and with the third
tank, since the seal 44 will render ineffective any
portion of the tank interior lying between it and
valve assembly.
the open end of the tank. The oil is vented from 15 As shown, oil can be drawn from tank 4| on
the closed end portion of the tank through the
the suction stroke of the piston 48 to ?ow through
holes 43 into the space surrounding the shank
check valve 10 into passage 13 and groove 14.
portion 42b of the plunger from whch the oil
Pressured oil can be by-passed from plunger 48
is fed into the system.
through check valve 16 into passages 18 and 19
When it is desired to ?ll the system with oil or
back to the tank, as hereinafter described. In
Figure 15 the passageway 19 is shown diagram
other operating ?uid, the plug 46 and spring 45
are removed, a rod is threaded into the threaded
matically as being in the ring block 35 whereas,
well portion of the plunger, and the plunger is
as shown in Figures 10 and 14, this passageway
retracted toward the cover plate 31. Both plugs
19 is actually a groove in the cover 31 communi
shown in Figure 15 are removed from the cover
plate 31 and oil or other fluid is poured into one
plug aperture while the other plug aperture acts
as an air vent. The retracted plunger allows the
cating with groove passageway 69. The con
nected grooves 19 and 59 by-pass the oil from
passage 18 back to the tank, while the groove 69
also supplies oil to the pump through check
valve 16.
tank 4| to be ?lled with oil. As shown in Figure
7, a pump assembly 41 is provided in another 30 Fluid can also ?ow from the groove 14 into a
aperture of the ring block 35. This pump assem
passage so to the valve seat 8| of the third valve
bly includes a piston 48 slidably operating in the
assembly where it can force the ball 82 off of
bore of a block 49 contained in the aperture and
the seat against the pressure of the spring 83
connected to a carrier 59 for a roller 5| adapted
and then flow into a passageway or groove in
to ride on the cam track Ma. The carrier 50 is
the cover. The groove 84 communicates with a
slidably mounted in a sleeve 52 carried by the block
passageway 85 in the ring block, which passage
35 and projecting therefrom into the space be
way communicates with a groove 86 around the
sleeve 56 of the plunger assembly to a passage
tween the block and the back wall 2|b of the hub.
way 81 in the ring block connected through a
A coil spring 53 acts on the carrier 50 to urge it
outward from the sleeve 52 and seat its ?ange 50a 440 passageway 88 to the chamber of the dumbbell
on a shoulder 52a provided in the sleeve. The
cam track Mo on which the roller 5| rides recip
rocates the piston 48 to pump ?uid supplied
thereto from the tank 4| as will be more fully
hereinafter described.
As shown in Figures 12 and 13, the ring block .
35 has diametrically opposed apertures there
through each containing a plunger assembly-55.
Each plunger assembly 55, as shown in Figure 12,
includes a sleeve 56 seated in theaperture and
slidably receiving therein a plunger member 51
carrying a seal 58 in sliding sealing engagement
with the sleeve. The plunger member has a but
ton end portion 51a projecting through an aper
ture in the bottom plate 39 of the block into the
space between the block and the back wall 2 lb of i
the hub. As shown in Figure 5, this button end
51a of the plunger acts on the pin 30 to rotate the
blade B thereby changing the pitch of the blade.
As shown in Figures 7 to 11, a valve assembly
66 is provided in another aperture of the block
ring 35. This assembly 66 includes a block 6|
disposed in the aperture of the ring block 35 and
slidably receiving a dumbbell type valve 62. The
valve 62 has a stem projecting through the bot-\
tom plate 39 of the ring block and attached to a
carrier 63 for a roller 64 adapted to ride on the
track portion MD of the control member l4. A
sleeve 65 slidably receives the carrier 63 and is ’
The valve 62 can connect the passageway
88 with a passageway 96 communicating through
a groove 9| in the cover plate with the ends of
both plungers 55 to move the plungers against
the pins 30 for rotating the blades into low pitch.
Alternately, the valve 62 can block the passage
way 88 and join the groove 9| and passageway
90 with a passageway 92. This passageway 92 in
the ring block 35 communicates with a groove 93
around the sleeve 56 of the second plunger as
sembly 55 and the groove 93, in turn, communi
cates with a passageway 94 back to the oil tank‘.
Operation of the device
The propeller pitch-changing device of this
invention includes a hub assembly rotatably
carrying propeller blades to turn about radial
axes from high pitch to low pitch positions, the
limits of which are determined by the positions
and settings of the set screws 32.
In normal
operation, the aerodynamic and other forces on
the propeller blades maintain the blades in high
pitch position because the blades are arranged
to have their centers of pressure forwardly of
their axes of radial rotation.
When it is desired to rotate the blades about
. their axes of radial rotation into low pitch posi
tion, the pilot merely pulls the Bowden wire or
control rod at. This rotates the control member
M in the mounting plate I0, and rotation of the
control member throws it axially forward be
cause the bolt heads |6a seat in tapered slots I5.
carried by the ring block 35. A spring 66 is pro
vided in the carrier 63 and acts thereagainst to
urge the carrier outwardly from the ring block
The control member has an inclined cam track
to abut a ?ange 63a thereof against a shoulder
or ramp | 4a on its front face together with a
65a of the sleeve.
Three check valve assemblies are provided in 75 ?at surface around this cam track. When the
eont‘fo‘l member is moved ‘forwardly "the dam
"one ‘set of pins on said bladeémounting devices‘,
track 14c ‘engages ‘the ‘rolleriei of thepuinp as‘
saintly ~4"! whilef'the surface Mb ‘around the cam
track engages ‘the roller ‘64 “of the valve ‘as
sembly 60.
‘hydraulicallyioperate'd "plungers‘in said hub a'r
rangedto engage ‘the‘s‘ame‘sides of the'other set
of pins on said mounting devices for moving said
devices to change the pitch of the blades carried
‘therebya pump ‘carried by said hub "for ‘supply
ing hydraulic ?uid'under-pres‘s'ure ‘to said'plung
hers, a tank carried by said hub "for ‘supplying
hydraulic fluid to'said ‘pump, a ‘control ‘valve ‘car
ried ‘by said hub for selectively connecting said
‘plungers ‘with said pump ‘and s‘aid'tank, and‘a
M g The ‘cam track M'a reciprocates the plunger
‘#8 'ofthepump and causes-the ‘pump to pump ‘oil
‘from the tank 4|, Thus, on the ‘suction shake
jg: the pump, 'oil‘is drawn in p‘ast‘the check v'a1v'e
"H and, “on the pressnre stroke or the pump, ‘the
thus drawn-‘m oil is ‘discharged against the/check
Valve ‘82. If the pressure is'tdo ‘great, theoil
shift'able cam mounted adjacent said hub having
‘a cam-‘track for actuating said‘pump a'ndia‘s'ur
The oil under pressure ?ows from the check
‘face for ‘moving ‘said valve whereby‘rotatio'n of
valve ii?intothe dumbbell‘valvemperatihg cham 1115 T-the hub anden‘gag'ementof the pump ‘and valve
berand the engagement ‘of the roller ‘64 of ‘the
with‘ the ‘control device will ‘create h-ydraulic'pres
will now past ‘the check valve ‘56 back to the tank.
sii'r‘e vactuating vthe iplun'gers ‘for ‘changing the
1~pitch oi the v"propeller blades.
valve with the surface Mb of the control men»
ber ‘moves the valve ‘to a position ‘so that the
3'oil will flow ‘to‘the ends of the plunger-s '55 throw
"i‘ng these plungers oiitwa'rdly again'st‘the "pins v‘3'0
rand thus rotating the blades B to low pitch posi
tions as determined ‘by the setting "of the "set
‘ 2_. In an engine including "a shaft, a'pro'pelle'r
_pitch-‘-'adjusting device comprising a’h‘ollow ‘hub
having radially extending ‘sockets, a ring block
lmem‘ber carried by said 'hub #in the hollow in
LISC‘I‘E‘WS ‘32.
lterior thereof and arranged tosurround ‘theen
The pump will continue to operateas long ‘as
l’g'ine shaft, said block member having a plurality
‘the "control member is ‘in its forward position and 25 ‘of recesses therein, ‘pl'un'gers slidably mounted in
‘the roller of the pump is in engagement ‘with the
some 'of said recesses, a control valve mounted
‘in another ‘recess, =a‘pump~mounted instill an
cam track; ‘Howeven-‘exce‘ssive pressures are not
developed by the pump since the 'oil ‘or other
other "recess, passageways-in said block opera
tively connecting ‘said 'plun'ger’s, said ‘pump and
hydraulic ?uid will ‘recirculate back to thetank
through the check valve '15. Only smalla‘mounts 30 ‘said ‘control valve for ?uid iintercommunication,
bf hydraulic '?uidarelne'cessary. ‘For example,
about 2/3 of a cubic inchb'f ?uid is‘s'u?icie'nt.
When it ‘is desired to permit the ‘blades to
' resume their ; high pitch ‘position, ‘the i-Bow‘deh
'“sai‘d'c'ontrol valve and said pump'havi'ng actuat
{i'ngmea'ns projecting from 'saidblock, propeller
1 blade mounting‘ devicesi'rotatably ‘carried in said
7 vsockets and ex'tendin‘giin'to the hollow interior
‘wire or'control rod “2D is 'again‘act‘uatedby the "35 10f the hi-ib ‘arranged t‘oi‘b'e acted "on by said
pilot to rotate the control member [4 in ‘the
f‘plu'nger ‘portions, and [a‘shiftable ‘cam member
‘arranged to ‘be carrie'dlb‘yan aircraft engine ad
reverse directionwhe'reupon the screw heads [6a
jacent said’ hubland shifted intoen'gage-r'nent‘with
and slots 15 retract the'control mei'nberto space
~-said projecting" portions of thepump'and control
the cam track l'lia'away from the roller 5|. The
spring 66 of the valve assemb1y~imoves th'e'dufnb 40 (“valve to ‘open the valve and reciprocate the pump
*for supplying l?uid under pressure to said plung
bell'valve'to place the passages 9| a‘ndi'llil in com“ers ‘to force the plunger‘s ‘outwardly from the
‘munication with the passages-'92 <and’194 back‘to
v‘ring block against ‘ the inwardly projecting ‘por
‘the tank. ‘The, aerodynamic and other forces on
ritio'ns ofthe ‘blade mounting devices?for rotating
the blades ‘are'thus suf?'cie'nt to rotate the blades
a‘ncithe pins 30 will force th'eTpIungers-‘EE back
said blade mounting devices. ‘
into the ring blockit?. The oil in back ‘of these
'pIunger's ‘can flow freely ‘through’ the ‘valve back
‘to the tank. _
From the above descriptions it‘v'vill be'clear-that
"the ‘device of'this invention is “simplelfool-prooi,
and inexpensive. It can \be'readily-installedJon
‘an'airplane without the aid 'ofspecialmounting
?xtures since the mounting plate is readily
adapted for connection with the conventional air
The following references are of record in the
to v‘?le
‘of this patent:
' Number
ICaldwe‘ll _________ __ "Mar. 9,193":
plane ‘engine while the hub 'w'ill replace'the ‘con;
vZipay ______ __>____V_'May 30, 1939
‘ventional propeller hub.
Re. 22,034
‘Hoover _; _________ __ 'Febf24, 1942
_ It ‘will, of ‘course, be ‘un'derstoo'd‘that various
details of construction vmay be varied ‘through
Ira wide range without departing from the‘prin
vciples of this invention and it is,'therefo're,-'not
"the purpose to limit the patent'grahted hereon
iother'wise vthan‘ne‘cessitated by the‘s'cop‘e ofth'e
:appended claims.
I' claim as my invention:
1. A propeller pitch-adjustin'gdevice compris
ing a propeller'hu'b haying a'hollow central’ por
tion ‘and radially v"exte‘ndir'igsockets communicat
ing with said central portion, ‘blade-mounting 'de
MacClatc'hie _____'__ 'May'v?, 1931
'Ba'llew ____ _'__.___Y___‘ July' 24,1934
; 2,0o2;112
"Patriarche _______ _- ‘May ‘28, 1935
Hoover _________ __ Dec/10,1935
‘ fcaiawe‘n _________ -QFeb. ‘25,1936
‘Welman _»____> ____ -QMar. 30, 1937
Dicks “If ________ __ Jan. 21, 1941
‘ 12,307,102
Blanchardet' a1. _'____ ‘Jan/5,1943
‘Hoover _~-i
-i ._. W__ Apr. 18,1944
_v__-___ Au‘gfl, 1944
‘ 2,404,290
Hoover __________ __*Ju1y'16,' 1946
vices rotatably carried in said“ sockets ‘and ‘hav
ing portions ‘projecting into said hollowportion
of the hub, pins extending laterally in angular
70 Number
1 119,164
"relation from vsaid ‘projecting "portions -?of the
“blade-mounting devices, set screws threaded in
v"said ‘hub arrangedto ‘engage opposite sides ‘of
' 635,992
' Country
¢lAuStra1ia,__.~_______.i__ NOV.~ 23,1944
France ___
Germany _
7-- 'Feb.>25,‘1926
d. Aug. 30, 1934
France ________ __-_‘May 28, 1935
Без категории
Размер файла
1 064 Кб
Пожаловаться на содержимое документа