June 24, 1952
Fi].ed Aug. 17, 1948
ID. J. GAFFNEY
PNEUATICALLY 0PERATED DIAPHRAGM MOTOR
2,601,511
3 Sheets-Sheet i
INVENTOR.
June 24, 1952
Filed Aug. 17, 1948
D. J. GAFFNEY
PNEUMATICALLY 0PERATED DIAPHRAGM MOTOR
2,601,511
3 Sheets-Sheet 2
INVEN TOR.
June 24, 1952
Filed Aug. 17, 1948
D. ,i.I. GAFFNEY
PNEUMATICALLY 0PERATED DIAPHRAG MOTOR
2,601,511
3 Sheets-Sheet 3
Patented June 24, 1952
ï 2,601,511
UNITED
STATES PATENT
OFFICE
1
This invention relates to a diaphragm operated
motor and particu]arly to such a motor for trans-
mitting straight line motion to open and close a
valve, governor, or the like.
In the conventiona] spring loaded diaphragm
motor, equipped with a valve device sometimes
referred to in this art as a positioner, the force
availab]e for downward thrust on the valve or
governor stem is the pounds per square inch
(hereinafter referred to as p. s. i.) output from
the positioner, whi.ch is norma]ly 20 p. s. i., rimes
the area of the diaphragm, minus the compres-
sion rate of the spring rimes the number of
inches it is compressed. In commercial practice,
about 75% of the pressure from the positioner
is absorbed by the spring at the end of the stroke,
and on]y 25% is availab]e for stem thrust. The
on]y force avai]ab]e for upward thrust at the
beginning of the downward stroke is the initial
compression of the spring, which never amounts
to more than 5 p. s. i. equiva]ent diaphragm
pressure in commercial practice.
The aval]able power in spring ]oaded dia«
phragm motors has proven inadequate to hand]e
large single seated contro]]ers, butterfly va]ves
and even large semi-ba]anced contro] valves with
extensive pressure drops. Consequent]y, there is
a definite need for a diaphragm motor with
more power.
One attempted solution to the prob]em has
been a sing]e diaphragm motor which is air
]oaded on top of the diaphragm by a valve de-
vice, and loaded on the bottom with a constant
air supp]y set by a sma]] regu]ator. The reçu]a-
tor is set af a pressure equa] to one-ha]f the
maximum output of the valve device and thus
has a differentia] pressure avai]ab]e which is
equa] to one-ha]f the supp]y pressure to the
valve device. If the valve device supp]y pres-
sure is 20 p. s. i., the regu]ated pressure on the
bottom of the diaphragm is set at 10 p. s.i. If
the valve device pressure goes to zero, 10 p. s. i.
is availab]e for upward force, and if 'the valve
device output goes to 20 p. s. i., there is 10 p. s. i.
available for downward force.
It has been round, however, that such a motor
is hot suiïïcient]y powerfu] for ail purposes.
Furthermore, a single diaphragm bas a certain
amount of s]ack fiopping back and forth with
equa] pressures on both of its sides. This allows
diaphragm head movement resu]ting in disp]ace-
ment equiva]ent fo the volume in the diaphragm
s]ack without compressing the air in one side of
the casing. If is desirab]e, however, fo have the
diaphragm movement resisted af ail rimes by
the compressibflity of the air.
Itis an objeçç 0f the nFention to provide a
2,601,511
PNEUMATICALLY OPERATED DIAPHRAGI
IOT.OR
Donald J. Gaffney, IarshMltown, Iowa, assignor
to Fisher Governor Company, Marshalltown,
Iowa, t corporation of Iowa
Application August 17, 1948, Serial No. 44,780
7 Claires. (CI. 121--48)
2
powerful pneumatically operated diaphragm
motor.
If is also an object of the invention to pro-
vide such a diaphragm motor in which diaphragm
5 movement is resisted at ail rimes and in which
there is no s]ack.
It is a further object of the invention to pro-
vide a powerfu] pneumatic double diphragm
motor.
l0 If is another object of the invention to pro-
vide a double diaphragm motor in combination
with a pneumatic reversing valve means or re]ay;
also to provide such a combination for use with
a valve device which admits or exhausts pres-
15 sure fluid from one side of the motor and also
operates the reversing valve.
Another object of the invention is to provide
a system wherein the direction of motion of
the pneumatic motor may be reversed by a sire-
20 ple change in piping connections.
With these and other objects in view, the in-
vention consists in the construction, arrange-
ment and combination of the various parts of
my device whereby the objects contemp]ated are
25 attained, as hereinafter more fu]ly set forth,
pointed out in the claires and i]lustrated in the
accompanying drawings, wherein:
Figure 1 is an e]evationa] view with parts
thereof in section, of one embodiment of the in-
30 vention;
Figure 2 is a section view of a portion of the
valve device shown in Figure 1;
Figure 3 is an e]evational view, Partia]ly in
section, of a second embodiment of the invention
35 wtih the pneumatic valve means and valve
vice shown in an inverted position from that
shown in Figure 1; and
Figure 4 is an en]arged sectional view of the
reversing re]aF.
40 Referring specifica]]y to the drawings, par-
ticularly Figures 1 and 2 for a detai]ed descrip-
tion of the flrst embodiment of the invention, a
valve body is indicated genera]ly at | and may
be any conventional control valve, butterfly valve,
45 turbine governor control, or the like, we]l known
in the art. A mechanism for operating the valve
or governor includes a double diaphragm assem-
b]y general]y indicated at , operating a recip-
rocating stem 3, a conventiona] valve devïce
50 and a reversing valve means 6 being connected
to each other and to the double diaphragm
semb]y by suitable piping to be described. The
reversing valve means per se is disclosed and
claimed in the copending application of Ceci] M.
55 Johnson, Serial No. 44,662, filed August 27, 1948,
ïor Pneumatic Reversing Relays.
The double diaphragm assembly 22 comprises an
9»601»511
upper cup-shaped casing member 2], a lower cup-
shaped casing member 28 and an intermediate
annular or ring shaped member 28. An upper
diaphragm 8|, formed of rubber or synthetic
rubber-like material, is clamped between the cas-
ing members 2 and 28, and a lower rubber or
synthetic rubber diaphragm 82 is clamped be-
tween the casing members 28 and 29. Bolts (no.t
shown) are provided for retaining the casing
members together.
The valve stem 28 is provided with an enlarged
portion 88, vhich is disposed within the double.
diaphragm member 22. The enlarg¢d-.portion 85:
of stem 28 engages with a plate 84 disposed on
the underside of the diaphragm 5:|'. A. plate
engages with the upper surface of the diaphragm
8| and is clamped to the plate 84 with the-diar
phragm 8| therebetween by a nut
A plate 8] is disposed beneath the enlarged
portion 88 in contact with the upper surface o.f. 2O
the diaphragm 82. A plate 38. clamps the:. dia-
phragm 2 between itself and. the..plate .5. by
means of a nut 89 secured fo. stem 28. Möve
ment of either diaphragm is, therefore, trans*.
mitted to the other without stck. Afmospheric
pressure is present betwee the. diaphagms 81
and 82.
The stem 23 extends through the lower casing
member 28 and into the casing 2.|, a packing
gland 49 being provided in the lower casing pr-- 30
tion 28 for the stem
The diaphragms 1 and 2 divid the double
diaphragm 22- into an upper chamber 4 |, a lower
chamber 42 and an intermediate chamber 43. A
conduit or pipe 44 communicates, with the upper 5
chamber 4|, and a conduit4S communicates with
the lower chamber 2, for s purpose hereinafter-
described.
A valve plate 4G supports, levers- 4; 48 and
9. The lever ] is pivotally connected to valve 40
stem 28 at 59. The levers ] and 48 are con-
nected together and are pivotally supported on
the plate at 52. The lever 9 is pivotalty con-
nected to the plate. 4 at 5| and is provided-with
a longitudinal slot 52a. The lever 8 is also piv- 45
otally connected to a block 55 which slides in slot
2a, so that vertical movement of the stem
ïotates lever 9 about its pivot 5|. A threaded
member B is pivotally connected to the lever
at 5 and has a threaded abutment member 55 50
thereon which engages with a spring ], and is
adjustable to vary the compression.thereof.
A combination bellows and valve member, gen-
erally indicated at 59, is illustrated, in detail in
Figure 2 and comprises a main bo.dy portion
having an open ended casing. 55 secured to one
side thereof adjacent spring ], and a closeoEcup --
shaped member 6 | secured to the otherside, there-
of. A betlows' 2 is secured to the sde of the
main body portion 8 facing the spring ], and a. 60
bellows 3 is secured to the other side of the main
body portion 9 and is contained within the cas-
ing 6. Rods G4 and extend through openings
88 in the body portion
secured to bellows 3, and plate 5] secured to 65
bellows 52. Spring 5] also engages the outside
of plate 8] and tends to collapse bellows 52.
The plate 5] is provided with a central open-
ing 8 therein, which provides a seat for a valve
member 59, which is a part:of a valve assembly [, 70
which in turn has a second valve member ?.2 on
if inner extremity. A spring 79. engages t!e
inner valve member ]2 and- the plate 5] tends to
maintain the valve member
formed in body member
4
and ] are s/so provided in body member 58 in
communication with a conduit ]. The valve
member ]2 operates to open and close passages
and ]5, which communicate with conduit ]G, in
a manner hereinafter described A conduit ]],
which commcates with a standard instrent
or controller (hot shown), also communicates
with a passage ] in body , which passage
opens into a chamber $ formed between casing
member 6 andbellows . Chamber ]9 is, obvi-
eusly, hermetically sealed.
Anohe conduit , which communicates with
cöduit. 4 and. lower chamber 42 of the double
dipagm mCmher , ao communicates with
a passage $ in body , which in turn com-
mucates with pssages in body $ through
which ods d extend. Conduit is,
thereïore, in communication with the terior of
thebeHo.ws... nd,$.
T.he revesn_ valva me.ans comprises cen-
trl body pot=tion Sg, t.o hich is seced n up-
per body portion 85 and a lower body po.rtion .8.
A chamber_ 8-is foed in £he central body por-
tion 84 of rev.erin valve means 26, and a co-
d $$ .communicates with the chamber.
tough a bore $$ at. o end thereof and with
co.ndui. 4.and $ I at. the ohr end therf.
A aphgm .91 formedof rubber or synthetic
r.ubber is clamped-betzeen the upper per.tion
and the central portion $ of the reversing valve
moins, and the diaphragm 92 is clamped between
the.lewer portion $ and the central portion 4 of
the.çeversing vale mea. Bol.ts may be utilized
for re£aing the-parts together. The effective
area-of the lower diaphragm 92 is approxately
twiee tha.t of the upper diaphragm 9 l. A stem
is secured to the upper and lower diaphragms
and 9, in anF. stable manner, the stem $$ beg
previded with a central psage 9 extending
therethrough. A valve assembly @-has an upper
alve member and a lower valve member
The lower va¢lve member 9 normally closes the
uper end of pssageg. The upper body portion
$5 of çelay 2 is provided with a boss 9, which
internally screw thçeaded to receive a plug 95. A
spring 99 engages with the plug $ and with the
upper valve member 9 to normally bias the-valve
member 9-into engagement with its seat
surro.unding a passage I- in body portion , as
best shown in.Figure 4.. e sprng 9 also biases
thevalve:member 9 into engagement with its seat
I.2" on top of stem 9, as shown in Figure 4.
A passage I. is provided in the upper body por-
tion . of reversing valve me 2 and commtmi-
cates t one: end with pipe 4, which in turn is
h commucation with upper chamber l of the
double diaphrm member 22. e other end of
passage $ communicates with a chamber 19,
which is forme.d aboe diphragm 91. A second
passage I is provided in the upper portion
reversing vale means 2, which commicates
at cne end with a conduit I$, and at its other
end with a chamber I I above valve member
The eonduit I also communicates with conduit
G and with a conduit , which latter condui
conects with a regulated air supply.
The lowez body portion $$ is provided with an
internally threaded boss I 9, into which is screwed
a hol!ow plug I I, having a vent 112 in the side
ther_eoL A spring I I$ ngages the closed end of
the pug I I I and engages with a plate 114, which
is secured to diaphragm 2, thus tendg to bias
stem 93 upwardly in engagement with valve
member .
8
Operation o! Fgures
Referring first to the reversing valve means
assuming a 20 p. s. i. air supply through conduit
188, then with no pressure at conduit 8|, ad-
justing screw or plug | | | fs screwed down fo ad-
just the spring il3 until the diaphragm or de-
livery pressure in .conduit ÆÆ fs 20 p. s. i. The
effective area of diaphragm 92 fs twice that of
diaphragm 9, as stated hereinbefore. If the
area of diaphïagm 8| is equal fo y, the area of 10
diaphragm 82 is equal to 2y. If the instrument
or control pressure at 8! is increased 1 p. s. i.,
there will be an increase in force on diaphragm
92 equal to 2y and an increase in force on dia-
phragm 9! equal fo y. This leaves a net un- 15
balanced downward force on the diaphragm
sembly equal to y and, consequently, the assemb]y
will move, opening the bleed valve 98. This will
allow air to escape from the chamber 184 until
the pressure on the top of diaphragm 9! is re- 20
duced 1 p. s. i. The diaphragm assembly will
again be in static balance, and the bleed valve
88 closed. Thus, it becomes apparent that with
every pound increase at 8 |, one pound decrease
will result at 44.
If there is a 1 p. s. i. decrease at 8|, this will
result in a 1 p. s. i. increase at 44, because the
diaphïagm assembly of the reversing valve means
28 wfll move upwardly, opening inlet valve 95
and permitting increase in pressure in chamber
|84 and in conduit 44 until the pressures are
again balanced, whereupon the inlet valve
closed.
leferring now fo the complete air circuit, start-
ing with the air from the instrument or con-
troller which enters through conduit 77, increas-
ing air pressure will cause the bellows assembly
82, 83 tobe moved fo the left as viewed in Figure
2, which opens the air supply valve 72 allowing
air supply pressure entering through conduits |07
and 78 fo flow into the chamber formed by the
two bellows 82, 83 and through conduit 8! into
lower diaphragm chamber 42 of the motor 22.
The same increase in pressure is also registered
in chamber 87 of reversing valve means 28 which,
as explained above, causes an unbalance in the
relay diaphragm assembly and causes it fo more
downwardly al]owing air to escape from chamber
|84 through passage 94 and bleed ourlet
This lowers the pressure in the chamber 4! of the
motor 22 an amount equivalent fo the fise in pres-
sure in the chamber 42 of motor 22. There is
now an unbalanced force on the main diaphragm
assembly 3 , 32 which causes the valve stem
fo more upwardly. This supplies compression fo
the spring 57 through the levers 47, 48 and 49,
which balances the increase in pressure on bel-
lows assembly 82, 83, causing supp]y valve
again close. This places the system again in
balance. If, due to hysteresis in the diaphragm
assemb]y 3, 32, sticking in the stuffing box 48
or unbalanced pressure forces on the valve or
governoï being operated, the valve stem 23 does
not more immediately, air will continue to bleed
through the inlet valve 72, consequently increas-
ing air pressure in the chamber 42 and decreasing
pressure in the chamber 4! untfl the valve stem
23 moves or untfl the pressure in chamber 42 has
increased to the equivalent of the air supply, that
is, 20 p. s. i., and the air pressure in chamber 4! î0
has reached zero. This makes avaflable for mov-
ing the valve stem 23 a force equivalent to the
product of the diaphragm area 32, rimes the sup-
ply pressure. For example, ff the diaphragm area
is 100 square inches and the air supply is 20 p. s. i.,
there is a 2000 pound force available to move
the valve stem 23.
Upon a decrease of pressure from the instru-
ment or controller through conduit 77, the bel-
lows assembly 82, 83 will more to the right as
viewed in Figure 2. Since the inner valve 72 is
seated at 73, it cannot more further fo the right.
Consequently, the left hand bellows head
breaks away from bleed valve 89, opening the bleed
port 88 and allowing air to bleed from the cham-
ber formed by the bellows 82, 83. This decreases
the pressure in chamber 87 of reversing valve
means '28 and in chamber 42 of the motor 22.
The decrease in pressure in chamber 87 causes
an increase in pressure in chamber 4! of motor
22, as explained above. The unbalance on the
diaphragm assembly '31, 32 wfll now cause the
valve stem 23 to more downwardly,. vhich,
through levers 47, 48 and 49, will decrease the
loading on spring 57 until the spring load again
balances the pressure load from the instrument
or controller in the chamber furmed by bellows
83 and cup member 8 I, thus closing bleed valve
89 and plaing the system again in balance.
25
Descripio o/Fgure 3
Referring now fo Figure 3 for a descripiion of
the second embodiment of the invention, it is first
30 noted that the valve device 24 and the reversing
valve means 28 are identical wiih that described
with respect fo Figures 1 and 2, except that they
are inverted. urehermore, the bellows assembly
shown in Figure 2 is ideniical in Figure 3 as fs
35 the valve or governor fo be operated. Where the
parts are She saine, She same numbers bave been
given in Figure 3 as in Figures 1 and 2. One of
the advantages of the inveniion fs ihai by merely
inverting the valve device 24 and reversing valve
40 means 28 and making ihe proper piping con-
nections, ihe direction of operation of valve stem
23, upon increase and decrease in instrument or
control pressure, may be reversed. In the em-
bodiment shown in Figure 3, the principle of
45 operation of the motor, which is given number
! 22, is the same as discussed with respect fo Fig-
ures 1 and 2.
The motor |22 comprises an upper cup-
shaped casing member |27, a lower cup-shaped
50. casing member |28 and an intermediate annular
casing member 129, having a wall |45 exCending
across the annular member |29 with an opening
|38 centrally thereof. A diaphragm |3! of tub-
ber or the like is clamped between the casing
65 members |27, 129, and a similar diaphragm |32
is clamped between the casing members |28 and
129.
A reciprocating sleeve 133 surrounds a stem
within the casing 122, and is adapted to slide in
C0 opening 138 in the partition |45. The sleeve is
secured at ifs upper end to a plate |34, which,
with a plate |35 and nut |38, clamps the dia-
phragm 13! to the stem 123 and sleeve 133. The
sleeve 133 is secured at its lower end to a plate
|37, which, with a plate |38 and nut 139, secures
the sleeve 133 and stems 23 and 123 to the lower
diaphragm ! 32. A stuffing box ! 48 is pïovïded in
the lower casing member |28 for the valve stem
There is thus formed in the motor ! 22 an upper
air chamber 14! and a lower air chamber
A conduit |.4 opens into the chamber 14! and
communicates with conduit 45 and 8|. Also
formed within the casing |22 is a chamber |48
75 between diaphragm |3| and partition |45, and a
»601511
chamber 147 .between diaphragm 132 and par-
tition ! 4.
A suitable plug 8 fs provided in the top cas-
ing member 27, and a needle valve . fs pro-
vided in casing member 29, which fs also pro-
vided with passages ! ! and ! 2 communicating
with chambers 48 and , respectively, when
valve 9-fs open. The two chambers 46 and
are fiiled .with a -liquid having a relatively
freezing point, and the needle valve 9 restricts
the passage between the chambers 4 and
The diaphragm spacer or sleeve $3 fs a closely
machined fit in the partition . In order for
the diaphragm assembly , 12 fo move, liquid
must be displaced between chambers 46 and
7 throughthepassages and 2. This gives
the diaphragm ssembly high degree of sta-
bility, which may be controlled by the needle
valve 9.
Operaion o Figure 3
The operation of the device fs exactly the saine
as hat described with respect fo Figures 1 and 2,
except that upon an increase in instrument or
control pressure in conduit 7, the valve stem 23
moves downwardly, whfle a decrease in instru-
ment or control pressure causes the valve stem
23 to move upwardly.
From the foregoing, if will be apparent that I
have provided a double diaphragm motor valve
which fs extremely powerful, and that the motor
valve, in combination with a pneumatic revers-
ing valve means, provides improved operation
and affords a reversal of movement in a very
simple manner.
Some changes may be ruade in the construc-
tion and arrangement of the parts of my device
without departing from the real spirit and pur-
pose of my invention, and if fs my intention fo
cover by my claires any modified forms of struc-
ture or use of mechanical equivalents which my
be reasonably included within their scope without
sacrificing any of the advantages thereof.
I claim as my invention:
1. In a pneumatic system, the combination
of a pneumatic motor for imparting reciprocating
movement to a member, a valve device adapted
to effect admission of fluid pressure to said
motor and exhaust fiuid pressure therefrom, a
reversing valve means for said motor controlled
by said valve device, said motor including a
casing, two spaced diaphragms scanning the
casing to form therewith a first chamber, a
second chamber and an intermediate space be-
tween the diaphragms, means for securing said
diaphragms together and fo the member to be
reciprocated, a supply of fiuid under constant
pressure, fluid connections between said con-
stant pressure supply and said valve device and
reversing valve means, a supply of fiuid under
variable pressure connected fo said valve device,
fiuid connections fo said first and second cham-
bers, one of said last connections communicating
with the reversing valve means and the other
with said valve device, and movable valve mem-
bers and passage, in said reversing valve means
and said valve device so arranged that an
crease in said vriable pressure fluid supply
effects an increase of pressure in one of said
chambers and a decrease in pressure in the other
of said chambers, and vice versa when said var-
fable pressure fiuid- supply, decreases.
2. A pneumatic motor for imparting recipro-
cating movement to a member, said motor com-
prising a closed casing, said casing including an
8
upper member, a lower member and an inter-
mediate member, said intermediate member pro-
viding a partition, a first diaphragm extending
across said casing above said partition and being
5 clamped af ifs periphery between the upper and
intermediate casing members, a second dia-
phragm extending across said casing below said
partition and being clamped at its periphery be-
tween the lower and intermediate casing mem-
10 bers, said diaphragms with the partition and
casing forming four chambers, namely, an upper
chamber above the first diaphragm, a lower
chamber below çhe second diaphragm, a chamber
between the first diaphragm and the partition,
15 and a chamber between the second diaphragm
and the partition, saoEd chambers between the
diaphragms and the partition being fflled with
liquid, a cormecting passage between the cham-
bers filled with liquid, and means for connecting
20 sald diaphragms together and to the member
to be reciprocated, said cormecting means in-
cluding a s]eeve surrounding said member tobe
reciprocated and extending through an opening
disposed centrally of said partition, said sleeve
2 being in contact with said member to be re«
ciprocated adjacent the portion thereof which
extends through said partition and also closely
fitting the opening in said partition whereby any
passage of fiuid between the two chambers
9 through said opening fs substhntially prevented.
3. A pneu:rnatic motor for imparting recipro-
cating movement to a member, said motor com-
prising a closed casing, said casing including
an upper member, a lower member and an inter-
5 mediate member, said intermediate member pro-
viding a partition, a first diaphragm extending
across said casing a.bove said partition and being
c!amped at its periphery between the upper and
intermediate casing members, a second dia-
49 phragm extending across said casing below said
partition and being clamped at its periphery
between the lower and intermediate casing mem-
bers, said diaphragms with the partition and
casing forming four chambers, namely, an upper
45 chmber above the first diaphragm, a lower
chamber below the second diaphragm, a cham-
ber between the first diaphragm and the parti-
tion, nd a chamber between the second dia-
phragm and the partition, said chambers be-
50 tween the diaphragms and the partition being
fflled with liquid, and means for connecting said
diaphragms together and fo the member fo be
reciprocated, a connecting passage between said
third and fourth chambers extending through
55 said partition and a restricting valve for con-
trolling the fiow of fluid between said chambers
through said passage.
4. A pneumatic motor for imparting recipro-
cating movement fo a member, said motor com-
0 prising a closed casing, said casing including an
upper member, a lower member and an inter-
mediate member, said intermediate member pro-
viding a partition, a first diaphragm extending
across said casing above said partition and being
65 clamped ai its periphery between the upper and
intermediate casing members, a second dia-
phragm extending across said casing below said
partition and being clamped at its periphery
tweenthe lower and intermediate casingmembers,
70 said diaphragms with the partition and casing
forming four chambers, namely, an upper cham-
ber above the first diaphragm, a lower chamber
below the second diaphragm, a charnber between
the first diaphragm and the patition, and a
75 chamber between the second diaphragm and the
9
9601511
10
partition, said chambers between the diaphragms
and the partition being filled with liquid, means
for connectJng said diaphragms together and fo
the member fo be reciprocated, said connecting
means including a sleeve surrounding said mem-
ber tobe reciprocated and extending through an
opening disposed centrally of said partition, said
sleeve being in contact with said member fo be
reciprocated adjacent the portion thereof which
extends through said partition and also closely
fitting the opening in said partition whereby any
passage of fiuid between the two chambers
through said opening is substantially prevented,
a connecting passage between said third and
fourth chambers extending through said parti-
tion, and a restricting valve for controlling the
fiow of fluid between said chambers through
said passage.
5. In a pneumatic system, the combination of a
pneumatic motor for imparting reciprocating
movement fo a member, a valve device adapted
to effect admission of fluid pressure to said
motor and exhaust fiuid pressure therefrom, a
reversing valve means for said motor controlled
by said valve device, said motor including a cas-
ing, two spaced diaphragms spanning the casing
to form therewith a first chamber, a second
chamber and an intermediate space between the
diaphragms, means for securing said diaphragms
together and to the member tobe reciprocated,
a supply of fluid under constant pressure, fiuid
connections between said constant pressure sup-
ply and said valve device and reversing valve
means, a supply of fiuid under variable pres-
sure connected fo said valve device, fiuid con-
nections fo said first and second chambers, one
of said last connections communicating with the
reversing valve means and the other with said
valve device, and movable valve members and
passages in said reversing valve means and said
valve device so arranged that an increase in said
variable pressure fiuid supp]y effects an increase
of pressure in one of said chambers and a de-
crease in pressure in the other of said chambers,
and vice versa when said variable pressure fiuid
supply decreases, said diaphragms having sub-
stantially equal effective areas.
6. In a pneumatic system, the combination of
a pneumatic motor for imparting reciprocating
movement fo a member, a valve device adapted
to effect admission of fluid pressure to said motor
and exhaust fiuid pressure therefrom, a revers-
ing valve means for said rnotor controlled by
said valve device, said motor including a casing,
two spaced diaphragms spanning the casing to
form therewith a first chamber, a second cham-
ber and an intermediate space between the di-
aphragms, a partition extending across the cas-
ing in the space between the diaphragms, means
for controllably connecting the spaces formed
between the diaphragms and the partition,
means for securing said diaphragms together and
fo the member fo be reciprocated, a supply of
fiuid under constant pressure, fiuid connections
between said constant pressure supply and said
valve device and reversing valve means, a supply
of fluid under variable pressure connected fo
said device, fiuid connections fo said first and
second chambers, one of said last connections
communicating with the reversing valve means
5 and the other with said valve device, and mova-
ble valve members and passages in said revers-
ing valve means and said valve device so
ranged that an increase in said variable pres-
sure fiuid supply effects an increase of pressure
10 in one of said chambers and a decrease in pres-
sure in the other ofsaid chambers, and vice versa
when saoEd variable pressure fiuid supply de-
creases.
7. In a pneumatic system, the combination of
15 a pneumatic motor for imparting reciprocated
movement fo a member, a valve device adapted
fo effect admission of fiuid pressure to said motor
and exhaust of fiuid pressure therefrom, and a
reversing valve means controlled by said valve
20 devlce, for said motor, said motor including a
casing, two spaced diaphragms spanning the cas-
ing to form therewith first and second chambers,
a partition extending across the casing between
said diaphragms, means extending through the
25 partition for securing said diaphragms together
and for imparting movement thereof to the ruera-
ber fo be reciprocated, a supply of fiuid under
constant pressure, said constant pressure supply
being connected to said valve device and to said
30 reversing valve means, a supply of fiuid under
variable pressure connected to said valve device,
fluid connections to said first and second cham-
bers, one of said last connections communicating
with the reversing valve means and the other
35 with said valve device, said reversing valve means
being effective fo increase the pressure in one of
said chambers when the pressure in the other de-
creases and fo decrease the pressure in said one
chamber when the pressure in the other in-
40 creases, the space between both of said dia-
phragms and said partition being filled with
liquid, a passage between said liquid filled cham-
bers affording passage of liquid therebetween and
a restricting valve in said passage fo control the
45 fiow of liquid therethrough.
DONALD j. GAIFNEY.
FNCF.,S CITD
The following references are of record in the
50 file of this patent:
UNITED STATES PATENTS
55
6O
65
Number
1,937,244
2,092,019
2,372.,345
2,376,671
2382,941
2,400,048
Number
14,235
3,058
644,689
Naine Date
Pelton ........... Nov. 28, 1933
Randel ............. Sept. 7, 1937
Temple ........... Mar. 27, 1945
Dodson ........... May 22, 1945
Moore ............. Aug. 14, 1945
Jones .............. May 7, 1946
IOIEIGN PATENTS
Country Date
Germany ............... of 1881
Great Britain ........... of 1884
Germany ......... June 14, 1937
