US 3822966 A
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ill   3,822,966 cClocklin  J y 1974 4] HYDRAULIC PUMP Primary ExaminerCarlton R. Croyle  Inventor. hsdairlirirulrel B. McC1ocklr n, Owatonna, Assistant Examiner Richard Sher Attorney, Agent, or Firm-Hofgren, Wegner, Allen,  Assignee: Owatonna Tool Company, Stellman & McCord Owatonna, Minn.
 .Filed: Oct. 26, 1972  Appl. No.: 294,818  ABSTRACT I A hydraulic hand pump having integral reservoir $5. C1 417/311, 254/93 H, 417/568 associated with a y having a handle assembly for nt. Cl F041) 49/08, B66f 5/04  Field of Search 417/568 307 operating the piston member of the pump. The pump 54/63 has relief valve structure mounted in the body and a communicating with the reservoir with use of a part of the same flow path for supplying fluid to the pump pis-  References Clted ton and with a passage mounting both an intake valve UNITED STATES PATENTS and an outlet check valve. An outlet sure port and a 2,412,414 12/1946 Mueller 254/93 H release valve associated therewith has a return passage 2,447,650 8/1948 Haumerson 417/307 X l di to reservoir 3,081,007 3/1963 Lightburn 417/568 FOREIGN PATENTS OR APPLICATIONS 3 Claims 2 Drawing Figures 173,452 7/1958 Sweden 417/307 T a fi M 7 53' d" W I 42 40 m 1/ Y L. 7 44 i 12 16' ff 100 j I i J F? L 340 :5 :I 1 60 I 7 2 5 71 F 6'! s a; a
HYDRAULIC PUMP BACKGROUND OF THE INVENTION operating jacks and other hydraulic devices wherein a portable source of hydraulic power is required. As a hand tool, the cost of a hydraulic hand pump is important as well as maintenance and repair.
SUMMARY A primary objective of the invention disclosed herein is to provide a hydraulic hand pump which is constructed for ease of manufacture, with minimal number of parts and which may be easily disassembled for repair or replacement of parts with simple reassembly.
In the invention disclosed herein, the pump has a body provided with suitable passages and which mounts an intake valve, an outlet check valve, and a release valve and with a relation of flow passages whereby both the relief valve and intake valve can use a flow path which, in part, is common and leads to a reservoir which is self-contained with the pump. Additionally, a passage which supplies hydraulic fluid to a bore in which the pump piston is mounted and which communicates with the reservoir extends to an end of the body and has a multi-step diameter to provide valve seats for both the intake valve and an outlet check valve. The latter valves are positioned within the body passage and held in position by a closing member fitted into the passage and with springs positioned between the parts to yieldably hold the intake valve and the outlet check valve in closed position.
The pump. body has a pressure port with an outlet I passage leading thereto for receiving fluid pumped by the piston of the pump and with the outlet passage extending beyond the pressure port and terminating in a seat which opens to a release valve chamber and a release valve mounted therein. A retum passage extends along a generally straight line between the release valve chamber to an end of the body communicating with the reservoir whereby the return passage and other passages may be accessible for machining from either a face of the pump body which extends into the reservoir or from an opposite face of the pump body.
The hydraulic pump has a relief valve with a settable spring and an adjustable perforate member for setting the spring force and with said adjustable perforate member also functioning as a positioning element for a filter to provide filtering of the hydraulic fluid which flows to the bore mounting the pump piston and past the intake valve.
In view of .the foregoing, an object of the invention is to provide a new and improved hydraulic pump and, more particularly, a hydraulic hand pump having parts and flow passages arranged to minimize the number of parts required and the cost of manufacture.
Another object of the invention is to provide a hydraulic hand pump embodying the features and advantages as set forth in this Summary.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical section of the hydraulic hand pump, taken generally along the line 1-1 in FIG. 2; and
FIG. 2 is an end elevational view of the hydraulic hand pump with parts thereof shown in section and taken generally along the line 2-2 in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT The hydraulic hand pump has a body, indicated generally at 10, with an outwardly extending part 11 which connects to a reservoir tube assembly, indicated generally at 12, and which includes a tubular member 15 having an end 16 swaged onto an end plug 17 with a sealing O-ring l8 interposed therebetween. The opposite end of the tubular member 15 threadably attaches to the exterior of the outwardly extending body part 11, as indicated at 19, and with a sealing O-ring 20 interposed therebetween. The pump body has a bore mounting a movable pump, piston 26 with the piston 26 movable in a retainer 27 threaded into an enlarged end of the bore. A seal member 28 surrounds the pump piston 26.
The pump piston 26 is reciprocated in the bore by a handle assembly, indicated generally at 30, including a handle 31 extended into an arm 32 pivotally mounted by means of a pair of spaced legs 33 and 34 to a body section 35 by a pivot pin 36. The handle assembly 30 connects to the pump piston 26 by a pin extending between the spaced legs 33 and 34 and engageable within a slot formed by spaced members 41 and 42 formed at the exposed end of the pump piston.
The outwardly extending part 11 of the pump body has a relief valve chamber with a first passage 51 extending between the relief valve chamber 50 and the bore 25 for the pump piston 26. The passage 51 has two sections of different diameter to provide a step intermediate its ends on which a relief valve ball 52 may seat, with the ball being urged against the seat by a spring 53 acting on a ball retainer 54 which engages against the ball 52. The opposite end of the spring 53 seats against an adjustable perforate member threaded into the relief valve chamber and with this member being provided with a series of flow passages 61 whereby fluid may flow therethrough. Rotation of the adjustable member 60 permits the setting of the pressure at which the relief valve will open. The adjustable member 60 also provides a locater for a filter screen 65 which is positioned against the adjustable member and which is held in position by a friction-type snap ring 66. When a pressure created by the pump exceeds the setting of the relief valve, the relief valve ball 52 moves off its seat whereby fluid can flow through the passage 51 and the relief valve chamber 50 into the reservoir.
A second passage extends from the relief valve chamber 50 to an exposed end 71 of the pump body and has a multi-step diameter in order to provide a valve seat 72 and a valve seat 73. The end of the passage 70 is closed by a closure plug 75 threaded into an end of the passage. The passage 70 movably mounts an intake valve member 76 formed of hexagonal stock whereby it is movably guided in the passage 70 while permitting flow therepast. The intake valve member 76 has a conical end coacting with the. valve seat 72 whereby on the upstroke of the pump piston 26 fluid can be drawn from the reservoir, past the intake valve member into the bore 25. On the pump stroke of the pump piston 26 the intake valve 76 closes. Fluid under pressure flows along the passage 70, past the valve seat 73, and to an outlet passage 80 leading to a pressure port 81.
An outlet check valve includes a ball 82 coacting with the valve seat 73, with the ball moving off its seat during flow of fluid to the pressure port 81 but being seated to prevent reverse flow.
From the foregoing, it will be seen that the first passage 51 providing for relief valve operation and the second passage 70 both communicate with the reservoir through the relief valve chamber 50 and that both the intake valve 76 and the outlet check valve 82 are positionable within the passage 70 through the opening closed by the closure plug 75.
A spring 85 is seated in an opening in the inner end of the closure plug 75 and engages the outlet check ball 82 to urge the latter towards its seat 73 and a spring 86 is fitted within a recess in the intake valve member 76 and engages against the outlet check ball 82 whereby the intake valve member 76 is yieldably urged against its seat.
As seen particularly in FIG. 2, the outlet passage 80, which connects passage 70 with the pressure port 81 extends beyond the pressure port 81 into a release valve chamber 90, with the end of the outlet passage 80 forming a valve seat 91 for a release valve member 92 having a conical end coacting with the seat. A guide 95 threadably seats in the release valve chamber, with a sealing O-ring 96 positioned to prevent leakage and with a knob 97 having a stem 98 threaded into the guide 95 engaging the release valve member 92 to hold the release valve member 91 on its seat. Backing off of the threaded stem 98 releases the release valve member 92 from its seat whereby fluid can flow from the pressure port 81, past the valve seat 91 to a return passage 100 extending along a generally straight line from the release valve chamber 90 to the end of the body which opens into the reservoir.
With the construction disclosed herein it is possible to machine a plurality of openings and passages with a minimum number of set ups of the body 10, with too]- ing entering from the end faces of the body 10. The first passage 51 and second passage 70 are arranged to 4 share a common passage to the reservoir, namely the relief valve chamber 50.
As will be noted in FIG. 2, the relationship of the components enables the single outlet passage 80, which extends in line with the axis of the release valve chamber 90 to coact with the passage 70, the pressure port 81 and the release valve chamber.
The multi-step diameter passage houses a number of valve components built-up, one upon the other, for providing the necessary interaction with easy assembly and disassembly of these components. Access to these components is provided by removal of the closure plug 75.
1. A hydraulic pump comprising, a pump body with an outwardly extending part, a reservoir tube assembly fitted onto said part, means defining a bore in said body and a movable piston therein for pumping hydraulic fluid in response to reciprocation of the piston, a pair of passages communicating with said bore and with a chamber in said body part open to the reservoir, said pair of passages being generally parallel and opening to an end of said chamber, an intake valve in one of said passages, a relief valve in the other passage, said relief valve including a spring and an adjustable seating member for said spring in said chamber, openings in said seating member permitting flow therethrough between the reservoir and said pair of passages, a filter screen spanning said seating member, means for holding the filter screen in position adjacent said seating member, a pump pressure port, and an outlet check valve.
2. A hydraulic pump as defined in claim 1 wherein said one passage extends through said body with a pair of steps providing valve seats, said outlet check valve having a ball engaging one of said seats, said intake valve being formed of hexagonal stock with a recess therein, a first spring in said recess of the intake valve and engaging the ball to urge the intake valve to closed position and a second spring urging the ball against its seat.
3. A hydraulic pump as defined in claim 1, a release valve chamber in the body, a straight-line outlet passage connecting said pressure port, said one passage terminating in a seat for said release valve chamber, a release valve in the release valve chamber in communication with said pressure port, and a return passage in said body extending along a straight line from said release valve chamber through said outwardly extending body part to communicate with the reservoir.