US2585351A

US2585351A - Hydraulic jack

Info

Publication number: US2585351A
Application number: US769150A
Authority: US
Inventors: Fred M Siedenburg
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-08-18
Filing date: 1947-08-18
Publication date: 1952-02-12
Anticipated expiration: 1969-02-12

Description

Feb- 12, 1952 F. M. SIEDENBURG HYDRAULIC JACK 2 SHEETSSHEET 1 Filed Aug. 18, 1947 INVENTOR.

Patented Feb. 12, 1952 UNITED STATES PATENT OFFICE This invention relates to an improved bydraulic jack and one of its objects is to provide a jack with a reservoir of oil or pressure fluid hav-- ing a flexible and collapsing wall and provided with valve controlled communication with the pressure'fluid charging chamber of the hydraulic pump or pressure generator, so that only the pressure liquid will flow to the pressure gen erator and all air will be permanently excluded-.- Another object of the invention is to provide the hydraulic jack with a manually operated is ton, a rocker for operating the piston, and a lever having adjustable connection with the rocker, so that the piston may be operated; with the lever in various angular relations to the rocker.

A further object of theinvention is to provide an improved valve system for controlling the pressure and the return flow of the pressure fluid, so that a closed hydraulic circulation may be maintained;

,For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a side elevation of the improved hydraulic jack, constructed in accordance with the present invention.

Fig. 2 is a similar view, showing the opposite side.

Fig. 3 is a. view looking from the right side of Fig. 1.

'Fig. 4 is a view looking down on Fig. 1.

Fig. 5 is a view looking up on Fig. l.

' Fig. 6 is an enlarged vertical sectional view, taken-on line't-B of'Fig. 4, looking in the direction of the arrows.

Fig. 7 is an enlarged fragmentary vertical sectional view, taken on line 'l-l of Fig. 4, looking in the direction of the arrows.

Fig. 8 is a horizontal sectional view, taken on line 8-8 of Fig. 6, looking in the direction of the arrows.

The hydraulic jack, according to the present invention, includes an outer protective casing l having an end wall II at one end and an i which is connected by matching screw threads IE to a block II, also enclosed by the casing Ill.

In the cylinder l a pressure ram i8 is slidably mounted. The innerend of this ram, which is cylindrical, 'is equipped with a sealing or packing ring l9, which is secured thereto by means of a central screw 20, against a washer 2|. The other end of the ram l8 extends slidably through the cylinder [5, and is sealed by means of a gland ring 22 and a packing disc or washer 23. The outer end of the ram I8 is formed with screw threads 24, so that it may be coupled to any ex ternal device.

"I he block l! is formed with a pressure fluid charging passage 25, which establishes communication between a pump cylinder 26 and the pressure chamber 2'! of the ram cylinder E5. The

end wall 12 at the other end thereof. This caspassage 25 is controlled by a ball check valve In the pump cylinder 26 a piston 25 operates, this piston being connected to a piston rod 30 by means of a screw 3i. The outer end of the piston rod 30 is provided with a lateral side openingslot 32, which receives a pin 33 of a rocker plate fimwhich is pivoted at 35 to a bolt 35, which is coupled by the screw threads 3! to the block ll, through the outer casing ill. The piston rod 30 where it extends from the pump cylinder 26 is sealed by a gland nut 59.

The rocker plate 34 is rocked by means of a lever 38, which is pivoted by a pin 39 to the rocker plate between the bolt 36 and the piston rod 30. The lever 38 has a bifurcated inner end 45 which straddles the rocker plate for this pur-- pose.

Enclosed by the outer casing 10 there is a flexible reservoir tube 4|; of oil resistant rubber or similar pliant and resilient material. One end oi this flexible reservoir tube is tightly fitted in a groove '42 formed in an end block 43, and the opposite-end is tightly fitted on an end plug 44. The end block 43 is provided with an axial passage 45, and the upper end of this passage is closedby a screw threaded filler plug 45, which can be operated through the end wall H of the casing H), which has an opening ii for this purpose.

The end block 43 is also provided with a lateral The pump cylinder 28 communicates with a passage 54, which extends through the block I! to its exterior, so that drainage and cleaning operations may be completed, and also communicates with the passage 41, and a ball check valve 55 is arranged in the pump chamber 26 to control the passage 54, and a plug 56 is threaded into the outer end of the passage 54 to keep the same normally sealed.

When the ram l8 reaches a safe limit of travel, it is desirable that it be held within the cylinder 15, and for this purpose the pressure liquid from the cylinder is caused to shunt through a by-pass 51, which extends through the cylinder and through the end plug 44 to establish communication between the interior of the flexible reservoir tube 4! and the pressure chamber 2'! of the cylinder 15.

It is evident that when the rocker plate 34 is rocked by means of the lever 38, the piston rod will be reciprocated to generate pressure in the pump cylinder 26, and pressure fluid will be forced into the pressure chamber 21 of the cylinder 15, to force the ram IS a distance controlled by the amount of pressure fluid admitted to the chamber 27 of the cylinder 15 at each pressure stroke of the lever 38.

When the piston rod 39 is moved outwardly pressure fluid will be drawn into the pump cylinder 26, and when the piston rod 30 is forced inwardly the pressure fluid will be prevented from leaving this cylinder by the action of the ball check valve 55, and will be forced into the main pressure chamber 21. The outer end of the lever is equipped with a handle 38 so that it can be operated to better advantage.

Due to the fact that a closed hydraulic circuit is established for the circulation of the pressure fluid, from the flexible and collapsible reservoir 41 to the pressure chamber 21, and from this pressure chamber back to the flexible reservoir tube, no air is permitted to enter the system. If the supply of pressure fluid in the flexible and resilient reservoir tube 4| drops too much, then the wall of this tube or reservoir will yield inwardly, thereby preventing any reduction of the internal pressure of the tube or reservoir, and also preventing back pressure on the pressure fluid.

The rocker plate 34 is provided with open edge recesses 34, on its outer convex surface which are engaged by the pin 40, which extends through the bifurcated inner end 40 of the lever, and which provides means for adjusting the angular position of the lever on the rocker plate.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims,

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

1. A hydraulic jack having a hollow cylinder closed at its top end by a block and provided with a slidable ram extendable from the bottom cf the cylinder, a flexible reservoir connected with the interior of the cylinder through valved passages formed in the block, a pump cylinder formed in the block between the valved passages and in communication with said passages, a piston slidably disposed in said pump cylinder, a piston rod connected to said piston within said pump cylinder and having one end extended from the side of the block, a bolt extended from the side of the block above the extended end of said piston rod and vertically aligned therewith, a pair of spaced semi-circular rocker plates extended along the opposite sides of said bolt and the extended end of said piston rod and pivotally attached to each with their rounded sides extended away from the side of the block, a lever extending from said rocker plates, said lever being pivotally connected to said plates at a point concentric with the rounded sides of said plates, and means releasably retaining said lever in an inoperative position along the side of the hollow cylinder or in an operative position extended laterally of the block.

2. A hydraulic jack having a hollow cylinder closed at its top end by a block and provided with a slidable ram extendable from the bottom of the cylinder upon flow of fluid under pressure through valved passages formed in the block, a pump cylinder formed in the block between the valved passages and in communication with said passages, a piston slidably disposed in said pump cylinder, a piston rod connected to said p;ston within said pump cylinder and having one end extended from the side of the block, a bolt extended from the side of the block above the extended end of said piston rod and vertically aligned therewith, a pair of spaced semi-circular rocker plates extended along the opposite sides of said bolt and the extended end of said piston rod and pivotally attached to each with their rounded sides extended away from the side of the block, a lever extending from said rocker plates, said lever having a bifurcated end straddling said rocker plates, a pin engaged through said bifurcated end and said plates concentric with the rounded sides of said rocker plates, and means releasably retaining said lever in an inoperative position along the side of the hollow cylinder or in an operative position extended laterally from the block.

FRED M. SIEDENBURG.

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

UNITED STATES PATENTS Number Name Date 1,745,024 Malone Jan. 28, 1930 1,811,556 Nilson June 23, 1931 1,855,508 Berck Apr. 26, 1932 1,990,004 Shannon Feb. 5, 1935 2,010,679 Rosenberry et al. Aug. 6, 1935 2,072,088 Dysart Mar. 2, 1937 2,170,029 Liddell et al. Aug. 22, 1939 2,351,145 Pearson June 13, 1944 2,352,390 Kirkland June 2'7, 1944