US2434296A

US2434296A - Combination high- and low-pressure hydraulic pump

Info

Publication number: US2434296A
Application number: US578757A
Authority: US
Inventors: Carl T Swanson
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-02-19
Filing date: 1945-02-19
Publication date: 1948-01-13
Anticipated expiration: 1965-01-13

Description

Jam. as, 1948. Q SWANSON 2,434,296

COMBINATION HIGH AND LOW PRESSURE HYDRAULIC PUMP Filed Feb. 19, 1945 I CARL T. SWANSON Patented Jan. 13, 1948 COMBINATION HIGH- AND LOW-PRESSURE V HYDRAULIC PUMP c n '1'. Swanson, Quonset Point, 1;. 1.

Application February 19, 1945, Serial No. 578,757

3 Claims. (Cl. rot-s7) (Granted under the m or March 3, 1883, as

amended April 30, 1928: 370 0. G. 757) This invention relates to a hydraulic pump and hasfor an object to provide a hydraulic pump which may be used iorlsupplylng eitherlow or high pressure as maybe needed and which will automatically supply high pressure instead of low pressure when the high pressure is needed to overcome the resistance.'

. A further object of this: invention is to provide a hydraulic pump which will supply low pressure until the resistance thereto becomes as great as the low pressure, whereupon the pump will automatically supply high pressure.

Still a further object of this invention is to provide a pump that may be manually operated for supplying fluid pressure, which pressure will shift automatically from low pressure to high pressure as the. resistance increases tosuch an amount that it may be only overcome by high pressure.

With the foregoing and other objects in view. the invention consists in the construction, combination and arrangement of parts hereinafter set forth, claimed and illustrated in the drawing in which, the figure is a partly sectional, partly detailed, elevational view of the hydraulic high and low pressure pump of this invention.

The hydraulic pump of this invention includes a main cylinder ii having inlet and outlet valves i 2 and i3 connecting the main cylinder chamber It by way of a passage I6 from an inlet fluid line I3 to an outlet pressure line ll. Threaded on the cylinder H is a cylinder cap i3 on which is mounted a flange plate 20 acting as a base for 8. lug 2i to which is pivoted a link 22, which link 22 in turn is pivoted at 23 to a pump arm 24 terminating in a pump handle 25.

Also pivoted to the pump arm 24 as at 26 is a second link 21 which is internally threaded for receiving the upper end of a piston rod 28. The piston rod extends through a bronze bushing 30 in the 'flange plate 20 and cylinder cap l8 into the main cylinder H. Movable within the chammain piston 3|, the upper end of chamber 34 being closed by a nut 35 threaded into the end of chamber 34. The connecting rod 28 is provided with a circumferential ridge 38 within the chamber 34.

tends through a'cylindrical chamber 38 formed;

in the main cylinder 3i and the piston rod end 31 is provided with a packing ring cooperating with the walls of the cylindrical chamber 38. The nut 36 is provided with a small vent 4| permitting the nut 35 to be assembled in position. A larger vent 42 is provided through the flanged plate 20 and cap i3 to the topof main cylinder l i thereby permitting the main piston 3i to move in the main chamber i4 .without'compressing any air .thereabove.

In operation, when the pump rod 24 is moved up and down manually by means of the pump handle 25, the double pivoted link 22 permits a straight vertical motion to be imparted to the connecting rod 28 and the main cylinder 3|. Due to the coil spring 33, the connecting rod 28 transmits its motion to the main piston 3i pumping the fluid from the inlet line it and through inlet valve i 2 to the outlet valve i 3 and outlet pressure line H until the resistance in the line I! becomes too great to continuemoving the main cylinder 3i up and down within its" chamber M in the main cylinder II and the operator then merely raises the handle 25 somewhat higher, thereupon com-. pressing spring 33 and moving the end 31 of connecting rod 28 toward the top of cylindrical chamber 38, the vertical movement being limited by the piston rod ridge 38 abutting the completely compressed spring. He then reverses his motion to a down stroke, the coil spring 33 assisting in this down stroke. The ring packing causes the end 3'! of connecting rod 28 to act as a piston within the cylindrical chamber 38 and due to the small cross-section of the cylindrical chamber 38 and piston rod end 31, considerably higher pressure will be created by this motion than it is pos- The lower end31 or the connecting rod 23 exsible-to create by the motion of the main piston 3i. it being noted that the cross-sectional area of the cylindrical chamber 38 is approximately one-fourth that of the cross-section area of themain cylinder chamber i4. 1 Obviously spring 33 could be omitted, and the back pressure alone could be relied on to'hold piston 3| at the top of the cylinder while high pressure is being supplied. As a result thereof the operator first creates a low pressure in the main chamber i4. until the back pressure from pressure line H becomes too great, whereupon. by merely raising the pump handle somewhat higher the pump is automatically converted into a high pressure pump as he operates the piston-like end 31 of connecting rod 28' in the smaller cylindrical chamber 38, thus continuing the pumping at a much higher pressure against the resistance in the pressure line i'l.

' memos der having fluid inlet and pressure outlet ports adjacent one end thereof, a pumping piston reciprocable within said main pump cylinder, a counterbored chamber extending through said piston with the small bore end toward said ports, a connecting rod reciprocably extending through said counterbored piston, one end of said connecting rod forming a, pumping piston within the small bore of said counterbored chamber, means on said connecting rod within the large bore of said counterbored chamber yieldably securing said connecting rod to said piston, said yieldable securing means comprising a coil spring embracing said connecting rod, an abutment on said connecting rod within the large bore of said piston limiting the movement of said rod through the small bore of said piston, one end of said spring being based on said abutment, an apertured closure member for the other end said small piston rod chamber when said yielding means is compressed, whereby said pump may deliver low pressure when said main cylinder piston is reciprocated and may deliver high pressure when said main piston abuts one end 0! its cylinder while said connecting rod is reciprocated within said small chamber in said piston rod against said yieldable connecting means.

3. A combination low pressure high pressure hydraulic pump comprising a main pump cylinder having fluid inlet and pressure outlet ports, a main pump'piston movable within said main cylinder, a pump arm, a link pivctally connecting said pump arm relative to said main cylinder, a connecting rod connected to said pump arm, a small cylindrical chamber in said main piston, an end of said piston rod extending into said small piston rod chamber, yieldabl means securing said connecting rod to said piston, said yieldable securing means comprising a coil spring embracing said connecting rod within a large cylindrical chamber therein, an abutment on said connecting rod within th large cylindrical chamber of said piston limiting the movement of said of said large bore, the other end of said spring being based on said closure member, the other end of said connecting rod extending through said apertured closure member in the end of the large bore in said piston and the end of said main .a connecting rod connected to said pump arm, a

small cylindrical chamber in said main piston, an end of said piston rod extending into said small piston rod chamber, yieldable means securing said connecting rod to said piston, said yieldable securing means comprising a coil spring embracing said connecting rod within a large cylindrical chamber therein, an abutment on said connecting rod within the large cylindrical chamber of said piston limiting the movement of said rod through the small cylindrical chamber of said piston, one end of said spring being based on said abutment, an apertured closure member for the other end of said large cylindrical chamber, the other end of said spring being based on said closure member, said yieldable means permitting said piston rod end to reciprocate within rod through the small cylindrical chamber of said piston, one end of said spring being based on said abutment, an apertured closure member for the other end of said large cylindrical chamber, the other end of said spring being based on said closure member. said yieldable means permitting said piston rod nd to reciprocate within said small piston rod chamber when said yielding means is compressed, whereby said pump may deliver low pressure when said main cylinder piston is re'ciprocated and may deliver high pressure when said main piston abuts one end of its cylinder while said connectingrod is reciprocated within saidlsmall chamber in said piston rod against said yieldable connecting means, said main piston having a packing preventing leakage between said piston and the wall of said main cylinder, said piston-like end of said connect-l. ing rod within said small piston chamber being provided with a packing to prevent leakage therethrough.

CARL T. SWANSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 28,090, Lindsay May 1, 1860 209,086 Stucky Oct. 15, 1878 1,047,007 Drugan Dec. 10, 1912 1,680,536 Gensmer Aug. 14, 1928 1,794,356 Baker Mar. 3, 1931 2,083,854 McGee June 15, 1937 FOREIGN PATENTS Number Country Date 3,503 Great Britain 1885