US2261438A - Bumper jack - Google Patents

Description

Patented Nov. 4, 1941 BUMPER JACK John Harwood, Jr.,

The Simmons land, Ohio,

Ashland, Ohio. assigner to Manufacturing Company, Asha corporation of Ohio u Application March 12, 1938, Serial No. 195,439

2 Claims.

This invention relates to an 'improvement in jacks and aims to provide a very rugged jack having a limited number of durable parts arranged in a very compact form.

While the jack herein disclosed is adapted for many uses, it is particularly adapted for the use popularly known as a. .bumper jack. Modern automobiles are so constructed and .arranged that it is difficult to place a. jack directly under the axle or.associated parts as was formerly done. The gage beneath a bumper bar or a projecting portion of the car frame at the front or rear of an automobile so as to lift one end or one comer of the frame as required to work on a wheel or axle.

An object of the present invention is to provide a jack of this type which is of the scifi-contained hydraulic type easily placed and manipulated by a person in standing position thus obviating awkward positions, soiled clothes and the usual discomforts of jack operation.

Another object of the present invention is to provide a powerful jack in a very compact form having a small number of parts easily manufactured and assembled so that the jack is simple, eicient, cheap to manufacture and takes very little storage space.

Other novel features of my improved jack and the details of structure by which I am enabled to provide all of the above described advantages are fully set forth in the accompanying specification and drawing and the essential features will be summarized in the claims.

In the drawing, Fig. l is an elevational view of my improved jack with certain alternative positions of the. parts being shownin dot-dash lines; Fig. 2 is an enlarged longitudinal sectional view through the jack of Fig. l; while Figs. 3 and 4 are transverse sectional views taken along similarly numbered lines of Fig. 2.

At the lower portion of the jack I provide lifting means including coacting cylinder and piston members, one of which is adapted to rest upon the ground or other supporting surface while the other member is arranged to move upwardly carrying a lifting hook or other attaching device and also supporting on its upper end a reservoir for the hydraulic fluid, suitable valve mechanism, pumping mechanism, etc. In the form shown the piston member I a. pin II which is supported in a base or shoe I2. The coacting cylinder member is indicated at I3 and is sealed and guided at its lower end by a cap I4 which is in threaded engagement with the lower end of the cylinder and has a central openis oscillatably mounted on type of jack here disclosed is adapted to ening through which the piston passes. Packing material I5 provides a sealing means at this point. The piston I 0 carries at its upper end a piston head I8 of leather or composition material providing a substantially duid-tight seal between the piston and the inner walls of the cylinder. Adjustably mounted on the cylinder I3 is the lifting hook I1 or other means for attaching the jack to the member to be moved. The lifting hook in the form shown has a split shank I8 embracing the cylinder I3 and clamped to the cylinder by a clamping screw I 9 which may be manipulated by the handle 23. Various positions of the lifting hook are shown in dot-dash lines in Fig. 1.

Rigidly mounted on the upper end of cylinder I3 is a kvalve block 2 I housing valves adapted to control the ow of fluid to and from the cylinder and piston lifting means III-I3. In threaded engagement with the upper end of the valve block is a reservoir cylinder 22. The upper end of this structure is sealed by the threaded cap 23. Located centrally of the reservoir is the hydraulic power cylinder 24 which is suitably supported on the valve block as by the threaded connection shown. The hydraulic plunger 25 is reciprocable within cylinder 24 and carries a suitably sealed piston head 25a. 'I'he upper end of the plunger 25 passes through 23 and is sealed in its passage therethrough by the packing gland 26. To the upper end of the plunger 25 is secured a suitable operating member. In the present form this comprises a cap or knob 21 having a downwardly extending sleeve 28 connected therewith, this sleeve being reciprocable along the outer face of cylinder 22 and cap 23. For guiding this reciprocating movement of sleeve 28 and for limiting that movement in the upward direction an annular ring 29 has threaded engagement with the inner surface of sleeve 28 at its lower end and slidingly engages the outer Surface of reservoir cylinder 22.

The hydraulic pump 24-25 acts as a force pump to deliver fluid from reservoir 3|! into the chamber 3l above the head of piston I0, To this end the valve block 2l at its upper end as shown in Fig. 3 is cut away at one side so as to provide an inlet passage 32 which is normally closed by the ball valve 33 sp pressed to closed position by the spring 34. This passageway communicates with the centrally located passageway 35 communicating between cylinder 24 and the chamber 3|. This latter is the outlet passage for fluid pumped by plunger 25 to the chamber 3| and is normally closed by the ball valve 36 which is a suitable opening in the cap pressed toward closed position by spring 31 which in turn is held in position by the hollow screw 38.

Within the valve block 2I I also for bypassing the pump valves so as to the return of iluid l 30 so that the jack will be lowered without other effort or manipulation on the part o! the operator. To this end a small bypass is provided at 39 which communicates at its upper end with reservoir 30 and at italower end with port 40 which communicates with passageway 35 below valve 36. This port is valve 50 which is sealed in the. valve body by a suitable packing gland wing nut 52.

' 'I'he operation of my jack is as follows: The shoe I2 is placed on the ground or oor beneath, for instance, the bumper bar of an automobile and the lifting hook I1 is raised into engagement with the bumper bar by adjusting its position as indicated in Fig. 1 and locking' the lifting hook by the clamp screw'i9. The plunger knob 21 permit is then grasped and plunger 25 is reciprocatedv 30 into chamto force liquid stored in reservoir ber 3|. It will be notedthat the parts are sufficiently long and attenuated so that when jack operation starts the knob 21 is substantially waisthigh to the operator to accomplish the beforementioned object of providing a device easily manipulated by a person in standing position. On each up stroke of plunger25 suction is created in cylinder fluid from reservoir sageway 35. On the down valve 33 closes and valve 36 opens, discharging the fluid under pressure into chamber 3l and lifting cylinder I3 relative to piston III and the lbase I2, thus gradually the` lifting hook I1 is provide means from chamber 3l to reservoir f controlled by the needle- 24, ball valve 33 opens and admits 30 to cylinder 24 and passtroke oi the plunger,

Sition. l

5I and controlled by the f communicating between said pump and said chamber,

raised' to the desired height. To lower the load,

port I0, whienhas been closed during the lifting operation, isopened by backing off the needley valve 50 which may be nicely controlled so as 4to permit fluid to returnat the desired rate from chamber Il through passageway I5, port 4I and bypass 33 to reservoir 30. l.y e load onlhook I1 and cylinder vI3 will thus" escend as rapidly as permittedvby the escape of iluid through the port 40 and the load will return to its lowermost por What I claim is:

1. A jack o! the class described comprising a piston of small diameter having a piston rod connected with a base, a long attenuated cylindrical tube coacting with said piston to form an expansible chamber between them, a liiting member carried by said tube on its outer wall, along tubular reservoir above said cylindrical tube, and

coaxial therewith, said reservoir being closed at the topby a wall, a valve block rigidly connected between said tube and said reservoir, a pump cylinder of smaller diameter than said reservoir l and supported by said block axially of said reservoir, a pump plunger coacting with said cylinder and extending through the top wall o! said reservoir, there being passageways in said block reservoir and said an inlet .valve permitting ilow into said pump from said reservoir; an outlet valve permitting flow out oi said pump into said chamber, there being means for returning fluid from said chamber to said reservoir to lower the jack, and the length of said tubular reservoir and of said cylindrical tube being such `that the operating end of said plunger at the top of said reservoir is at least substantially waist-high to an operator.

2. A jack as in claim 1, wherein the end of said pump plunger above said reservoiris provided with an operating knob substantially oi the diameter of said reservoir, a sleeveextends downwardly therefrom in sliding engagement with the outside of said reservoir, andthe diameter of said knob and sleeve is suillciently small to be easily grasped in the hand o! the operator.

JOHN rrenvvoon.` JR.

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