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Патент USA US3077847

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Feb. 19, 1963 -
R. s. DICKINSON ETAL
3,077,837
HYDRAULIC PUMPS
Filed March 16, 1960
3 Sheets-Sheet 1
RJWALD
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INVENTORS
MERV’IV BALTkA/n
BY
WJIBM,WAL
_
ATTORNEYS
Feb. 19, 1963
'
R. s. DICKINSON ETAL
3,077,337
HYDRAULIC PUMPS
Filed March 16, 1960
3 Sheets-Sheet 2
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INVENTORJ
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Feb. 19, 1963
R. s. DICKINSON ETAL
3,077,837 ’
HYDRAULIC PUMPS
Filed March 16, 1960
5 Sheets-Sheet 3
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3,977,837
Patented Feb. 19, 1963
2
1
FIG. 3 is a detail in section taken on the line III--III
3,577,337
HYDRAULIC PUMLPS
Ronald Sidney Dickinson and Mervyn Bartram, York,
England, assigncrs to Armstrong Patents Co. Limited,
Beverley, England, a British company
Filed h’iar. l6, 196d, Ser. No. 15,429
2 Claims. ((Zl. 133-41)
This invention concerns hydraulic pumps, and relates
of FIG. 2,
‘
FIG. 4 is a vertical sectional elevation of another em
bodiment of the invention, taken on the line IV-IV of
FIG. 5,
FIG. 5 is a transverse vertical sectional elevation taken
on the line V-—V of FIG. 4, and
FIG. 6 is a sectional detail taken on the line Vl--VI
of FIG. 5.
Throughout the various ?gures of the drawings, like
more particularly to hydraulic pumps for incorporation 10
reference numerals are employed wherever possible to de
in spring suspension systems, for example for road ve
note like parts.
hicles, wherein one region of a- suspension spring is car
In the hydraulic pump shown in FIGS. 1 to 3, a pump
ried by a hydraulic ram to which a hydraulic medium
body 10 is formed with an integral reservoir 12 for a
may be supplied under pressure or from which hydraulic
medium may be exhausted for the purpose of modifying 15 ‘hydraulic medium, and a semi-rotary spindle 14, adapted
for reciprocation from externally of the body 10 by con
the spring attitude relative to and on variation of a load
supported by said spring.
nection of a lever arm 16, for example to a vehicle sus
pension spring (not shown), passes through the reservoir
According to the present invention, a hydraulic pump
12 and is journalled in the body 10.
comprises a pump body formed with a reservoir for
The pump body 10‘ is provided with a pair of bores
hydraulic medium and with at least one bore communi 20
18, 20, and within the bore 13 is threadedly engaged a
cating with said reservoir, a semi-rotary spindle journalled
cylindrical liner 22 having displaceably received therein,
in said body and adapted for reciprocation from exter
a pump plunger 24 which at its upper end extends from
nally of said body, a cam carried on said spindle, a
the liner 22 towards the spindle 14. The spindle 14 has
plunger displaceably received in said bore and resiliently
a cam 26 ?xedly secured thereon, and the shape and
urged towards said cam for reciprocation thereby, an inlet
angular setting of the cam 26 on said spindleare such
valve for hydraulic medium at the reservoir end of said
that, over a wide range of angular position of the spindle,
bore, an outlet valve for said medium at the opposite end
the cam bears on the plunger 24 so that angular recipro
of said bore, said plunger being formed with passage
cation of the spindle results in reciprocation of the
means to permit the ?ow of hydraulic medium there
through, and a delivery conduit extending from said oppo 30 plunger within the liner 22, the plunger being resiliently
site end of said bore to an outlet connection provided on
the pump body.
The outlet connection may thus be placed in communi
cation with a hydraulic operating member such as a hy
draulic ram in order, during operation of the pump, to
supply hydraulic medium under pressure to said operating
member. Preferably the pump is further provided with
urged towards cam 26 by means of a spring 23.
The
plunger 24 is formed with passage means 30 by which
it communicates with the reservoir 12, and at its inner
end, within the liner 22, is provided with a shoulder to
receive a valve seat 32 against which a- ball valve member
34 is urged by means of a spring 36. Beyond the valve
seat 32, the passage means 30 is enlarged to form a cham
ber 38, and thus, on upward, i.e. induction, strokes of
the plunger 24, hydraulic medium is drawn from the
reservoir 12, past the ball valve member 34, and into the
connection and the reservoir, said relief valve being
chamber 38. At the end of the liner 22 remote from
adapted for opening on the attainment of a predetermined
that at which the plunger 24 is introduced, there is
angular position of said spindle within said body. For
threadedly engaged a member '40 which is bored to com
example, the passage containing the relief valve may be
municate with chamber 38 and counterbored to present
a further bore in the pump body, and the relief valve
may have a valve member adapted for unseating by 45 a shoulder receiving a valve seat 42 whereon resiliently
abuts a delivery ball valve member 44. The ball valve
means of a plunger in said bore and having a portion
member 44 is housed within an end cap 46 closing the
extending from said bore towards a further cam ?xed
member 40‘ except for apertures 48 through which hy
on the spindle, the cam being so arranged as to bear on
draulic medium is delivered, on downward strokes of the
the plunger when said predetermined angular position is
50 plunger 24, from the chamber 38 to the bore 18 of pump
reached.
body 10. From the bore 13, the hydraulic medium de
For the purpose of guarding against hydraulic locks
livered thereto passes through a conduit 50 formed in
between the pump and a hydraulic operating member to
body 10 to an outlet connection 52 provided thereon and
which it is connected, the pump may be provided with
adapted for connection to a hydraulic operating member
an overload valve arranged to communicate with the
outlet connection and with the reservoir, and set to open 65 such as a- ram.
A typical application of the pump described above
when a given hydraulic pressure is exceeded.
a hydraulic pressure relief valve arranged in a passage
formed in the pump body to extend between the outlet
In a modi?cation of the invention, instead of or in
is to a vehicle spring suspension system wherein one re
gion of the suspension spring is carried by a hydraulic
addition to forming the pump body with an integral reser
ram supplied with hydraulic medium under pressure by
voir, said body is provided with an inlet connection
adapted for communication with an independent reser 60 the pump. In such a suspension system, when the load
carried by the vehicle is increased and the chassis con
voir, and both said relief valve and said overload valve
sequently sinks relative to the spring, the supply of hy
(when provided) are arranged to communicate with said
draulic medium to the ram, and consequent extension of
inlet connnection and thence with said independent reser
said ram, enables the chassis to be restored to its original
you.
65 height to compensate for the increased load. In order to
The invention will be described further, by Way of ex
allow the reverse action to occur when the vehicle load
ample, with reference to the accompanying drawings, in
ing is decreased, the pump shown in FIGS. 1 to 3 incorpo
which:
rates a relief valve enabling hydraulic medium to ex
FIG. 1 is a transverse, vertical sectional elevation
haust from the ram back to the reservoir 12. For this
through one hydraulic pump embodying the invention, 70 pumpose, the bore 20 of the pump body 10) is provided
FIG. 2 is a sectional elevation taken, on the line 11-11
wtih a liner 54 which is bored at one end to present-a
of FIG. 1,
i
'
shoulder receiving a valve seat 56. A'ball valve member
8,077,837
ll.
58 is resiliently urged against the seat 56 by means of
valve are identical with that of FIG. ‘1, and therefore a
a spring 60 contained within an end cap 62 threadedly
engaged within the liner 54. The upper end of the liner
54 is bored to slidingly house a plunger 64 which, at its
end within the liner 54, is of reduced dimensions such
as to pass through the valve seat 56 and contact the ball
valve member 58. The opposite end of plunger 64 ex
detailed description need not be here repeated.
Both the embodiments of the invention described above
are shown as having the pump body 10 provided with lugs
11 for securing to a vehicle chassis or comparable mem
ber, the lever arm 16 then being connected to some con
venient part of the spring suspension system. The relative
connections of said body and lever arm to the chassis or
tends out of the liner 54 towards the spindle 14, and the
comparable member may, however, be reversed if desired.
latter is provided with a pro?le cam 66 against which
A number of modi?cations are possible within the
the plunger 64 is urged by means of a spring 63. A sur 10
scope of the invention. For example, the pressure relief
face 67 is provided on the cam 66 for the purpose of de
valve 56, 58 and 64 of FIGS. 1 to 3 may be be replaced
pressing the plunger and unseating the ball valve member
by the relief valve 82, 86 and 99 of FIGS. 4 to 6. Again,
58, and the range of angular positions of the spindle 14
over which this will occur Will depend upon the initial
although both embodiments of the invention are shown
To guard against hydraulic locks occurring when the
draulically power'assisted steering and hydraulically 0p~
It will be appreciated that, in the embodiment of FIGS.
said spindle being adapted for angular reciprocation from
externally of said body member, said body member being
as having a single lever arm 16 adapted for connection
setting of the cam on the spindle. Thus the spindle 14,
to a vehicle or other suspension system, the spindle 14
via the lever arm 16 and its connection to, e.g. a vehicle
may be arranged to extend from both sides of the body
suspension spring, is adapted to sense a predetermined
10 in order to receive a wishbone suspension member in~
condition of the suspension spring at which the relief
stead of lever arm 16, i.e. the pump may be incorporated
valve is to be opened or closed. When the relief valve
opens, hydraulic medium passes from the outlet connec~ 20 directly in said suspension system. Other practical appli
cations of the pumps than to vehicle suspension systems
tion 52, to the bore 20, past the valve member 58, through
are also possible, e.g. said pumps may be employed to
passage means 70 formed in the plunger 64, and back
supply hydraulic medium under pressure to vehicle hy
into the reservoir 12.
hydraulic ram or other operating member to which the 25 erated clutch mechanisms, and in any other structure
where a supply of hydraulic medium under pressure is
pump is connected is fully extended, the pump further
required
and means is available appropriately to recipro
includes a passage 72 formed in the body 10 between the
cate the spindle 14.
conduit 50 and the reservoir 12, and an overload valve
We claim:
arranged in said passage and having a valve member
1. A hydraulic pump comprising an at least partly
74 urged resiliently against a seat 75 by means of a spring 30
hollow body member, the hollow interior of said body
78. The spring is retained in position by means of a
member constituting a reservoir for a hydraulic medium,
threaded nut 80, and hence the nut 80 may be adjusted
a spindle journalled in and rockable relative to said body
to set the spring and hence valve member 74 to open at
member and extending into the hollow interior thereof,
a desired maximum pressure.
1 to 3, there may be more than one cam and plunger
assembly 22—48 provided, by suitably shaping the body
10 to have more than one bore 18, and by providing a
corresponding number of earns 26 on the spindle 14.
In contrast to the pump described above, wherein the
bores 18, 20 and their respective plunger and relief valve
assemblies are arranged beneath and in line with the
spindle 14, the pump shown in FIGS. 4 to 6 has a pair of
formed with a pair of bores in parallel, side-by-side rela
tion and each constituting a hydraulic cylinder, a recipro
cable plunger received in each hydraulic cylinder and
projecting from said cylinder into said hollow interior,
a ?rst cam carried by said spindle and extending sym
metrically on either side thereof, spring means in each
of said hydraulic cylinders for urging the plunger therein
against said cam, whereby said cam is enabled to re~
plunger assemblies arranged transversely of the spindle
to provide a symmetrical, double-acting pumping arrange 45 ciprocate said plungers responsive to turning movement
of said spindle, each of said plungers being axially bored
ment. In this particular construction, the pump body
and counterbored, a valve seat in each plunger at the
10 is therefore provided with a pair of bores 19 each cor
junction of the bore and counterbore therein, an inlet
responding to the bore 18 of FIG. 2, and each containing
valve member resiliently urged against said valve seat
a pump plunger assembly identical to the elements 22,
24 and 28 to 48 of FIG. 2. Upon the spindle 14 is mount 50 for passing hydraulic medium from said reservoir through
said plunger and into the hydraulic cylinder containing
ed a symmetrically shaped cam 27, and the springs 28
said plunger when said plunger moves in one direction
urge the plungers 24 against the cam 27, so that on angu
in said cylinder, hydraulic medium outlet means in said
lar reciprocation of the spindle 14, as described with
body member, means including a pump delivery valve
reference to FIGS. 1 to 3, the plunngers 24 are recipro
cated in liners 22 to pump hydraulic medium from the 55 at the end of each hydraulic cylinder remote from the
reservoir and connecting said remote ends of said cylin
reservoir 12 to the bores 19. A delivery conduit 51 is
ders to said outlet means for passing hydraulic medium
provided from each bore 19 to an outlet connection 52.
from said cylinders to said outlet means when the
To provide for the exhaust of hydraulic medium back
plungers move in the opposite direction in said cylinders,
to the reservoir 12, this embodiment of the invention has
a relief valve member 82 urged by means of a spring 84 60 said body member being formed with ?rst and second
passages extending between said outlet means and said
against a seat 86 formed in a passage 88 extending
reservoir, a plunger-operated hydraulic relief valve in
through the body 10 from the outlet connection 52 to
one of said passages and having the operating plunger
the reservoir. On the side of the valve seat remote from
thereof projecting into said hollow interior, a second cam
the outlet connection 52 (in the direction of exhausting
on said spindle and arranged to bear on said relief valve
hydraulic medium), the valve member 82 is continued as
a plunger 90 which bears against a face cam 92 ?xedly
mounted on the spindle 14 adjacent the cam 27. Thus,
by suitably setting the cam 92 on the spindle 14, the relief
operating plunger for opening said relief valve whenever
the spindle attains a predetermined angular position rela
tive to said body member, and a pressure responsive over
load valve in the other of said passages for permitting
of angular positions of the spindle.
70 the ?ow of hydraulic medium from said outlet means
to said reservoir whenever the pressure of hydraulic
Overload conditions between the pump and a hydraulic
medium at said outlet means exceeds a predetermined
operating member which it supplies are avoided by the
value.
provision of an adjustable overload valve arranged in a
2. A hydraulic pump comprising an at least partly
passage 94 between the outlet connection 52 and the reser
voir 12. The construction and operation of such overload 75 hollow body member, the hollow interior of said body
valve may be caused to open over a predetermined range
3,077,887
6
member constituting a reservoir for hydraulic medium, a
the outlet means and with the corresponding end of the
rockable spindle journalled in said body member and
extending into the hollow interior thereof, said body
member being formed with a pair of cylinders arranged
pump cylinder, a second cam on said spindle and ar
in parallel, side-by-side relation and each opening at one
of its ends directly into said hollow interior adjacent and
in alignment with said spindle, a cam carried on said
spindle within said hollow interior to register with one
of said cylinder ends, a pump plunger displaceably re
ranged to bear on the operating plunger of said relief
valve for opening said relief valve whenever the spindle
attains a predetermined angular position relative to said
body member, a second passage extending between said
reservoir and said ?rst mentioned passage and joining
said ?rst mentioned passage at a position intermediate
said ?rst and second cylinders and a- pressure responsive
ceived in the cylinder having its end registering with said 10 overload valve in said second passage, for permitting hy
draulic medium to ?ow from said outlet means to said
cam, spring means in said cylinder urging one end of said
reservoir whenever the pressure of hydraulic medium at
pump plunger against said cam for reciprocating said
said outlet means exceeds a predetermined value.
plunger responsive to turning movements of said spindle,
said plunger being axially bored and counterbored, a
valve seat in said plunger at the junction of the bore and 15
the counterbore therein, a pump inlet valve member resil
iently urged against said valve seat for passing hydraulic
medium from said reservoir through said plunger and
into said pump cylinder when said pump plunger moves
in one direction in said cylinder, hydraulic medium outlet 20
means in said body member, means including a pump de
livery valve connecting the other end of said pump cylin
der to said outlet means for passing hydraulic medium
from said pump cylinder to said outlet means when the
plunger moves in the opposite direction in said cylinder, 25
a plunger operated relief valve in the second cylinder
and having the operating plunger thereof projecting into
said hollow interior, passage means connecting the end of
said second cylinder remote from said hollow interior with
References Cited in the ?le of this patent
UNITED STATES PATENTS
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1,982,770l
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2,672,014
2,687,311»
2,784,978
2,825,579
2,935,313
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2,970,832
Ach ________________ -._ July 29,
Miller ______________ .._. Mar. 19,
Tollison ______________ 1- Dec. 4,
Rothrock ____________ __ June 23,
Belinkin ____________ .._ Aug. 14,
Yarger ______________ -._ Mar. 16,
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