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Патент USA US2127324

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Aug‘. 16, ‘1938.,
'
EQCANNON
>
2,127,324
'
PREFILL VALVE FOR HYDRAULIC PRESSES
Filed Oct. 10, 1936 V
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Aug. 16, 1938'. ~
‘
E. CANNON ~
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2,127,324,
PREFILL VALVE FOR HYDRAULIC PRESSES
Filed Oct. 10, 1936
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INVENTOR
. C'wrwwn/g.
BY
‘
‘
ATTORNEYS ,
‘
'
Patented Aug. 16, 1938
2,127,324
UNITED STATES '
,
r-a'riatrrv o-Fncs
2,121,324
ranrm. vanvn roa HYDRAULIC masses
Cannon, Rockville Centre, N. ‘2., assignor
to E. W. Bliss Company, Brooklyn, N. Y.,.a cor
poration of Delaware
Application 0mm: 10, 1030, sens-inn. 105,005
'
19 Claims. " (Cl, 121-38)
This invention'relates to improvements in pre-' valve which will not have the objectionable char
?ll valves for permitting the rapid ?lling of the , acteristics of the spring-closing type of valve as
'ram work chamber of a hydraulic press with oil, aforesaid and may be arranged to directly co-act
or other ?uid prior to setting up high pressure with the means for effecting quick advance of the
5 therein, and is described and illustrated herein. rain and to directly connect withva tank to per
as applied to such valves wherein means are .mit rapid ?lling of the ram work chamber as the
provided for quickly advancing. the press ram into ram advances.
'
'
engagement with the work.
.
.
A further object of the invention is the pro- ‘
»
Heretofore the quick advance of the main ram
10
in some hydraulic presses has been accom
plished by the use of one or more auxiliary rams,
vision‘ of a compact arrangement of pre?ll valve,
. a tank, and a rod or conduit for conducting ?uid 10
into a quick-advance chamber in the ram, all'
operated under relatively low pressure. During' co-axially disposed relativelyto the ram 01 a
the advance of the main ram in such presses, press, such arrangementvrequiring a minimum
and as a result of suction created thereby, ?uid of piping and yielding a maximum of eiiiciency.
A further object of the invention is the pro 15
" from a nearby reservoir is drawn through the
pre?ll valve into the ram work chamber of the . vision of means within the valve structure for by.
press, whereupon the pre?ll valve is closed to passing pressure from a point at one side of the
permit the setting up of pressure in said chamber valve to the ram work chamber at the other side
thereof, after the valve has been closed, thus ad
su?icient to perform the desired work. . For com
CO pactness and direct connection, both the preflll
ditionally minimizing the piping that is neces 20
valve and a ?uid tank have in many presses been
sary for operating a press.
mounted on the top of the press, co-axially with
the ram chamber, the quick advance of the ram
being accomplished by means independent of said
The foregoing and other objects are accom
plished by my invention as described and de?ned
in the following specification and claims and as
ram. In other presses a rod or conduit extends
axially within the ram to conduct ?uid into a
which:---
.
quick-advance chamber therein. and the preilll
Figure 1 is a vertical cross-section of a valve
valve is mounted toward one side of the axis of
the ram and is connected to the tank and the
according to my invention.
Fig. 2 is a vertical crossrsection of a modi?ed
30 ram chamber by suitable pipe connections.
My
present invention embodies a combination of
these. two arrangements, resulting in a more
compact and highly e?lcient structure which may
be economically constructed and maintained.
12 Li
illustrated in the accompanying drawings, in
My invention is disclosed and described herein
as applied to a spring-opening type of valve which
has certain advantages over a spring-closing
type of valve. The latter type, if arranged to
depend upon the suction in the ram work cham
ber to cause it to open and permit- the flow of
liquid into said chamber as the ram advances,
opens only to a very limited degree and, there
fore, does not permit a free and rapid flow of
liquid into the said chamber. Such spring-clos
43 ing type valves, of course, may be and have been
provided with auxiliary hydraulic chambers to
form of valve.
I
30
I
Fig. 3 is a horizontal section, looking upward,
on the line 3-3 of Fig. 2.
Fig. 4, is a vertical cross-section of a still
further modi?cation of my invention.
Fig.5 is a horizontal section, looking upward, 35
on the line 5-5 of Fig. 4.
.
.
Fig. 6 is a vertical cross-section of another
modification of my invention.
In the embodiment of my invention illustrated
in Fig. 1, I employ a substantially cylindrical cas 40
ing ll having coaxial bores l2 ‘and I3 toward the
upper and lower ends, respectively, of said cas
ing. A removable head I4 is secured upon the
upper end of the casing ii by bolts I! (only
one of the latter appearing in the drawings),
A co-axial passage it, of lesser diameter than
the bore l2, extends between the latter and the ,
bore ii to permit the passage of ?uid therebe
cause them to open by hydraulic pressure, in
which case additional pipes and auxiliary valves
are necessary to control the movement of the > tween. .The wall of- this passage is formed by an
pre?ll valve. It is obviously desirable, both from
the standpoint of eihciency of operation and com
pactness of design,‘ to minimize the piping em
annular valve seat i'l, ?tted tightly within the 50
‘casing Ii, and having a vertical seating surface .
i8 and an oblique seating‘ surface is.
.
ployed in such presses.
A slidable valve element 20 is accurately ?tted
within the bore l2 and is adapted to reciprocate
therewithin between an open position,—-as indi 55
_
An important object of my invention is the
provision of a spring-opening type of pre?ll
2
aromas
cated in the drawings. wherein the upward
movement or said element is limited by the head
il,-and a closed position, wherein the downward movement oi the valve element is limited
by the valve seat ll; said valve element having
a vertical seating suriace 2| and an oblique seat
impose su?lcient pressure upon the ram to enable
it to perform the desired work. A source of ?uid
pressure could, of course, be independently con
nected to said- chamber, necessitating a separate
pipe connection for that purpose. According to
my invention, however, the use of such separate
connections may be avoided, and to this end I
tively, cooperate with the seating surfaces ll and employ a by-pass arrangement whereby the port
II of the valve seat l'|_.=
20, which admits ?uid into the valve-closing
A compression spring 22 is disposed about a chamber 28, also serves for establishing suitable 10
10
reduced lower portion of the valve element 20, ?uid pressure in the ram work chamber 20.
and seats against the valve seat I‘! and a shoulder
A bore 2! is provided extending within the wall
24 on the valve element 2| to hold the latter in of the casing II from a point opposite the valve
an open position. A tank 2| is suitably mounted closing chamber 2| to a point near the ram work
ll upon the casing II and substantially surrounds chamber ll, an opening “I connecting said bore 15
the valve structure. One or more openings 2' with said valve-closing chamber and a passage
are provided in the casing ll leading into a 4| connecting said bore with the ram work cham
surge chamber 21 in the lower part of the bore ber. A check valve 42 is arranged to be held
l2 for permitting a tree ?ow, or surge of ?uid be- ' closed across the opening III by a compression
tween the tank 2| and said chamber at sub
spring 48 co-acting with a screw plug 44 which
ing surface 22, which seating surfaces. respec
stantially atmospheric pressure.
_
The bore l2 serves as a valve chamber com
also serves as a guide for said check valve. The
compression of the spring 43 is such that the
prising the surge chamber 21 and a valve-clos
check valve 42 may not open until the pressure
ing chamber 2| of inversely variable volumes,
within the valve-closing chamber 2| exceeds the
which vary with the reciprocation of the valve
element 20 therewithin. A port 20 opens into
the valve-closing chamber 2' to permit the ad
mission of ?uid tnereinto under pressure to move
the valve element to its closed position.
The bore It serves as a ram chamber compris
ing a ram work chamber 2| and a ram return
chamber ll‘ of inversely variable volumes, with
in which chambers a reciprocating ram ii is
accurately ?tted. This ram is somewhat elong
ated and substantially cylindrical in shape. An
upper portion of the ram is of enlarged diameter
and works within the said chambers between a
raised position, as indicated in full lines in the
drawing, and a lowered or advanced position, as
indicated in broken lines. The remainder of the
ram is of reduced diameter andextends down
wardly beyond the casing ii to engage the ma
terial being worked upon by the press, a ring 32
being ?xed within the lower end oi said casing
and about the ram to prevent leakage of ?uid
from the ram return chamber ll‘.
‘ The interior of the ram II is hollowed to form
a'cylindrical quick-advance chamber ll there
within. An elongated rod 24 is ?xed to the head
it by a nut II and extends downwardly centrally
through the valve-closing chamber 22, the surge
chamber 21, the passage II, and the ram work
chamber 30. The said rod extends through a bore
It in the valve element 2| and a bore 21 in the
upper portion of the ram Ii, and terminates
within the quick-advance chamber 22. The rod
34 has an axial passage 3. extending throughout
its length and opening into the quick-advance
chamber 22 to permit the admission of ?uid
thereinto under su?icient pressure to quickly ad
vance the ram 3i into engagement with the ma
terial being worked.
A port 30" is provided to permit the exhaustion
of ?uid from the ram return chamber 20' on the
advance stroke of the ramand to admit ?uid into
and chamber to return the ram to a raised posi
on.
Itwill beseen that after the ramhas been
lowered or advanced into engagement with the
70 material being worked, by the admission of ?uid
into the quick-advance chamber It, and the valve
element 2| has been moved to a closed position,
the ram work chamber It will contain ?uid at
substantially atmospheric pressure, and the ?uid
pressure in said chamber must be increased to
pressure required to move the valve element 20 26
to a closed position.
The cycle of operation commences with the
various parts in the positions shown in full lines
in the drawings and with ?uid under substan
tially atmospheric pressure in the tank 25 and in 30
all the various chambers and passages referred
to, except in the ram return chamber III‘ where
in su?lcient pressure is present to hold the ram
ii in a raised position.
Fluid is admitted under moderate pressure into 35
the quick-advance cylinder 33 through the pas
,sage II in the rod 24, the ram return cylinder
3.‘, meanwhile, being permitted to exhaust
through the port 30''. This causes the ram Ii to
descend into engagement with the material be
ing worked. The descent of the ram causes ?uid
from the tank 25 to be drawn or sucked through
the openings 20 into the surge chamber 21 and
thence through the passage It into the ram work
chamber 30,
Fluid is then admitted under relatively high
pressure through the port 29 into the valve-clos
ing chamber 28, causing the valve element 2| to
descend to a closed position. The continued in
troduction of pressure through the port 22 sets
up pressure in the valve-closing chamber 28 su?i
cient to open the check valve 42 and establish
communication between the valve-closing cham
ber 2| and the ram work chamber 30 through the
opening III, the bore 39, and the passage 4|, and 65
thus introduces a suitable working pressure into
the ram work chamber 30. The pressure in
troduced into the said ram work chamber through
the port 29 may be raised to the extent necessary
to permit the ram to fully perform its desired
work. At this stage of the cycle the ram 3| is in
substantially, the position indicated in broken
lines in the drawings.
It will be seen that after the check valve 42
opens, a substantially uniform ?uid pressure is 65
present in both the valve-closing chamber 28 and v
the ram work chamber 20. As the upper surface
of the valve element 20, which is subjected to
downward pressure, is of ‘greater area than the
lower surface thereof, which is subjected to up 70
ward pressure, it is obvious that there is a pre
dominant downward force exerted upon the valve
element 20 which operates to hold said element
in a closed position while working pressure is
maintained in the ram work chamber, it being 75
.
.
of the valve in this respect being governed in a
measure by the viscosity of the ?uid to be used.
In any event, such'grooves must not be large
enough in the aggregate to pass ?uid with suf
ficient rapidity to prevent the accumulation of
be sufiicient'to overcome in addition the expansive
force of the spring 23.
3
areas“
I apparent that the excess downward force must
I
L
/
_ The return stroke of the ram is accomplislzleld
vby simultaneously releasing the p
n
e
valve-closing chamber 28 and the quic .-advance
pressure in the chamber 20 upon the initial in
chamber It and introducing ?uid under pres
troduction of ?uid into said chamber through the
sure into the ram return chamber 30a, thereby
permitting the exhaustion of the chambers 2|
would' ‘ prevented from closing.
inlet 28, as under such conditions the valve
10 and 33, allowing the spring 23 to raise the valve
element 20, and forcing the ram 3i upwardly to
'
The y-passing means illustrated in Fig. 4 10
comprise amannular passage 49 formed by the
enlargement of the lower portion of the bore 38
in the valve element 20 and extending from the
bottom to a point near the'top of said valve ele
ment. Fluid connection is provided between the
passage 49 and the valve-closing chamber 28 by
'aneeccentrically-disposed axial passage 50 in the
valve element 20 extending from the top there
»of to a point therein opposite the upper end
of the annular passage 48, and by an opening II
connecting the latter with the passage 49. A‘
its uppermost position and permitting the ?uid
in the ram .work chamber 30 to surge upwardly
and outwardly through the passage IS, the surge
15 chamber 21, and the openings 26 into the tank
25, thereby completing the cycle.
It is highly desirable to provide means whereby,
on the return stroke of the ram II, as aforesaid,
the pressure within the .ram work cylinder 30
20 may be gradually relieved and reduced to sub
stantially atmospheric pressure, as otherwise the
check‘ valve 52 is guided within a bore 53 at the
instantaneous release of such pressure upon the
unseating of the valve element '20, combined with
the action of the spring 23, gives rise to severe
shock and to detrimental structural stresses in
the press. Means to thislend are disclosed and
claimed in my co-pending application, Serial No.
111,790, filed Nov. 20, 1936. As disclosed herein,
these means comprise a plurality of vertical
grooves 45 of various lengths in the lower part
lower end of the said axial passage and urged
by a compression spring 54 within the bore 63
toward a closing position across the lower end
of a tubular threaded seat 56 which is screwed
into the upper end of the axial passage 50.
The by-passing means illustrated in Figs. 1
and 4 operate similarly, but diifer principally in
that in the former the by-pass check valve and
passages are in the valve casing, while in the
latter they are in the slide valve. Although the
of the valve element 20. These grooves are dis
posed about and interrupt the vertical seating
accompanying drawings show only one by-pass.
check valve in each embodiment, it is obvious
surface II of the said valve element and extend
to the lower edge of said surface. As the valve
35 element 20 rises on the return stroke of the press,
the longer grooves 45 and then the shorter
that two or more such valves may be utilized,
if
desired.‘ ~
‘1
'
Fig. 6 illustrates by-passing means which are
very similar to and function similarly to the by
passing means shown in Fig. 1, the principal dif
ferences being that the by-pass ?uid connection
grooves 45, in succession. extend beyond the
upper edge of the vertical seating surface ll of
the valve‘seat l'|,-thus establishing a relatively
40 gradual ?uid connection between the tank 25
and the ram work chamber 30 and permitting a
between the valve-closing chamber 28 and the
ram work chamber 30 comprises pipe connec
in the latter, thereby eliminating any objection
tions I9‘ disposed outside of the valve structure,
able shock and structural stresses. This opera- , instead of the bore 39, opening 40, and passage
4| shown in Fig. 1 in the valve casing, and that
45 tion, although taking‘ place progressively to re
lease the pressure, takes place as a practical a check valve 56 of modi?ed form is employed
' relatively gradual reduction of the pressure with-_
' proposition in a fraction of a second.
I‘
for the same purpose as the check valve disclosed
The embodiments of Figs. 2 and 4, differ from in Fig.- 1.
Suitable pumping and valving means (not
that of Fig. l-in having a valve casing 48 and a
separate ram casing '41. They diifer also from 1 shown) are provided in the several modifications
50
the embodiment of Fig. 1 in the means for by
to-time and otherwise control the admission of
passing ?uid pressure from the valve-closing fluid into the several chambers and the exhaus
chamber 28 to the ram work cylinder 30 to estab
lish a relatively high working pressure in the
55
60
latter.
,
‘The by-passing means illustrated in Fig. 2
comprise grooves or slots 48 in the axial bore in
the valve element 20 txtending throughout the
entire length of said bore. While these grooves
tion thereof to achieve the desired cycle of opera
tion and the necessary ?uid pressures.
'
Myinvention has been described herein and
illustrated in the accompanying drawings, sole
ly for illustrative purposes, as employed in a
vertical press with a descending ram, but it may
obviously be employed in a‘ horizontal press or in
are su?iciently large to by-pass ?uid under pres- ‘ a vertical press with an ascending ram or in
sure, they, nevertheless, are, su?iciently small to
frictionally retard the passage of ?uid there
through and to permit the accumulation of pres
sure in the valve-closing chamber 28 to cause
the valve element 20 to move downwardly to a
closed position as a result of the introduction of
.?'uid into said chamber’ through the port 29.
Once the valve element 20 reaches its closed posi-'
tion, the greater total force upon the upper sur
face thereof, as compared to the total force upon
the lower surface thereof, operates'to hold the
said valve element in a closed position against
‘the compression of the spring 23.
It is obvious that larger or greater numbers of
75 by-pass grooves 48 may be provided, the design
presses disposed at any angle. Its employment
in such various presses and in various modi?ca
tions may obviously be resorted to without de~
parting from the spirit of the invention.
What I'claim is:
1. The combination with a hydraulic press hav
ing. a ram chamber, a ram adapted to recipro
cate within said ‘chamber, and a ?xed rod ex
tending within a bore in the ram, of a prefill
valve comprising a casing within which the said 70
?xed rod extends, a surge chamber in said casing
communicating withthe ramchamber, an open.
ing in said casing arranged to permit the flow
of ?uid into said surge chamber, a valve element
slidably mounted upon said ?xed rod within ‘said 75
4
2,127,324
casing, and means for reciprocating said valve
element within said surge chamber to control
the ?ow oi ?uid between the latter and the ram
chamber, the fixed rod being ?xedly connected
to said casing.
'
-
2. The combination according to claim 1
wherein the said ram, ?xed rod, and valve ele
ment all have a common axis 01' symmetry.
3. The combination according to claim 1
further characterized in having a tank for hold
ing ?uid, said pre?ll valve being disposed sub
stantially within said tank in a position to be
immersed in ?uid therein whereby to ‘permit the
ready ?ow thereof between said valve and said
15
tank.
'
toward the ram chamber, su?icient back pres
sure is created in the valve-closing chamber to
move the said valve element to its closed position.
8. The combination according to claim 7, fur
ther characterized in that the said passage is in
the said valve element and a?ords ?uid connec
tion between the two said chambers when the
said element is in closed position.
9. The combination, in a hydraulic press, 0!
a ram chamber, a surge chamber normally in 10
. open communication therewith, a casing, a valve
closing chamber, a reciprocating ram movable
within the ram chamber, a reciprocating valve
element movable within the valve-closing cham
ber and the surge chamber and having an inner 15
end adapted to substantially close the surge
chamber and ram chamber against communica
4. The combination according to claim 1
further characterized in having an interior hy
draulic chamber in the ram and the said ?xed ' tion when said valve element is in a closed posi
rod having an axial passage opening into said. tion and having an outer end adapted to receive
interior hydraulic chamber and being adapted hydraulic pressure to urge the valve element to
to conduct ?uid thereinto to advance the ram.
a closed position, and means for transmitting
5. The combination with a hydraulic press hav
?uid pressure between the valve-closing chamber
ing a ram chamber, a ram adapted to reciprocate
and the ram chamber, and being provided which
within said chamber, and a ?xed rod extending is ?xed to said casing and extends through the
within a bore in the ram, of a pre?ll valve com
said said valve element and into said reciprocat
prising a casing, an annular valve chamber,
ing ram.
within which the said ?xed rod extends, having
10. The combination according to claim 9, the
an opening in the wall thereof to permit the said means for transmitting ?uid ‘pressure com
passage of ?uid thereinto, an annular communi
prising an interior longitudinal groove in the
cating passage between said valve chamber and valve element adjacent to the ?xed rod and form
the ram chamber, an annular valve element with
ing, with the latter, a passage for transmitting
in said valve chamber extending around and ?uid pressure between the valve-closing chamber
adapted to slide upon said rod, and means for and the ram chamber.
sliding the valve element between an, open posi
11. The combination according to claim 9, the
35 tion and a closed position wherein a portion of said means for transmitting ?uid pressure com
said element extends across and closes said pas
prising an annular passage extending around the
sage, the ?xed rod being ?xedly connected to ?xed rod at one end of the valve element and a
said casing.
duct extending from said passage to the other end
6. The combination in a hydraulic press of of the valve element. .
a ram chamber. a valve-closing chamber, a surge
12. The combination, in a hydraulic press, of
chamber, and a communicating passage between
a ram chamber, a surge chamber normally in open
the latter and the‘ ram chamber, all having a
common axis of. symmetry, a reciprocating ram
communication therewith, a casing, a valve-clos- '
adapted to hydraulically work within the ram
chamber, a reciprocating slide valve element
adapted to hydraulically work within the valve
closing chamber and the surge chamber and
having a seating portion adapted to seat across
and close said passage when in a closed position,
a ?xed rod extending centrally through the said
valve element and communicating passage and
into the reciprocating ram, an opening in the wall
of said surge chamber to permit the admission
oi’ ?uid thereinto, and spring means for urging
55
the said valve element toward an open position
wherein ?uid may ?ow freely through said pas
vsage, the valve-closing chamber being adapted to
receive ?uid thereinto under pressure to urge the
valve element toward a closed position against
the force of said spring means, the said press
having a casing to which the ?xed rod is ?xedly
connected.
.
'7. The combination, in a hydraulic press, of
a ram chamber, a reciprocating valve element
adapted when in a_closed position to substan
tially close the said ram chamber whereby to
permit establishment of working pressure there
in, a valve-closing chamber adapted to hydrauli
cally move said valve element to its closed posi
70 tion, and means for passing ?uid from the latter
chamber to the ram chamber to establish work
ing pressure therein, said means comprising a
continuously open passage connecting the two
said chambers, the said passage being of such
76 restricted area that, as ?uid passes therethrough
ing chamber, a reciprocating ram movable with
in the ram chamber, a reciprocating valve ele
ment movable within the valve-closing chamber
and the surge chamber and having an inner end
20
25
30
35
40
45
adapted to substantially close the surge chamber
and ram chamber against communication when
said valve element is in a closed position and hav
ing an outer end, adapted to receive hydraulic 60
pressure to urge the valve element to a ,closed
position, and means for transmitting ?uid pres
sure between the valve-closing chamber and the
ram chamber, the said casing substantially sur
rounding all said chambers, and the said means 55
comprising a passage in said casing adapted to
transmit ?uid pressure between the valve-closing
chamber and the ram chamber.
13. The combination according to claim 12,
further characterized in having a valve adapted 60
to permit transmission of ‘pressure between the
valve-closing chamber and the ram chamber only
when the pressure in the valve-closing chamber
is greater than required to move the valve ele
ment to a closed position.
65
14. The combination, in a hydraulic press, of a
ram chamber, a surge chamber normally in open
communication therewith, a casing, a valve-clos
ing chamber, a reciprocating ram movable within
the ram chamber, a reciprocating valve element 70
movable within the valve-closing chamber and
the surge chamber and having an inner end
adapted to substantially close the surge chamber
and ram chamber against communication when
said valve element is in a closed position and hav 75
5”,
2,127,324
for transmitting ?uid pressure comprising an in
pressure to urge the valve element to a closed’ terior longitudinal passage in the valve element
ing an outer end adapted to receive hydraulic
adjacent to and partly de?ned by the fixed rod,
said passage being of such restricted area that,‘
position, and means for transmitting ?uid pres
sure between the valve-closing chamber and the
ram chamber, the said means comprising pipe
passages connecting the valve-closing chamber
as ?uid from the valve-closing chamber passes
therethrough, sumcient back pressure is created
in the valve-closing chamber to close the valve
(and the ram chamber.
15. The combination according to claim 14,
element against the action of said spring means. 7
18. The combination according to claim 'I, fur
ther including spring means coacting with the re 10
ciprocating valve element whereby to urge the
latter toward an open position, the back pressure
further characterized in having a valve adapted
to permit transmission of pressure, between the
valve-closing chamber and the ram chamber only
when the pressure in the valve-closing chamber
is greater than required to move the valve ele
created‘in the valve-closing chamber being sui?
cient to move the said valve element to its closed
position against the action of said spring means. 15
19. The combination according to claim '7; fur;
ther including spring-means coacting withthe re
ciprocating valve element whereby to urge the
- ment to a closed position.
15
16.‘ The combination according to claim 9, the
said means-for transmitting ?uid pressure com
prising an interior longitudinal passage in the
valve elementv adjacent to and partly de?ned by
latter toward an open position, the back pressure
the fixed rod, the said passage being of such re
stricted area that, as ?uid from the valve-closing
chamber passes therethrough, su?lcient back
pressure is created in the valve-closing chamber
to close the valve and permit the establishment
of working pressure in the ram chamber.
created in the valve-closing chamber being suffi 20
cient to move the said valve element to its closed
position against the action of said spring means,
the said passage being in the said valve element
and a?ording ?uid connection between the two
said chambers when the said element is in closed
1'7. The combination according toclaim 9, fur
ther including spring means coacting with the
reciprocating valve element whereby to urge the
latter toward an open position, the said means
.
position.
‘
EARL CANNON.’
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