US1759670A - Lifting jack - Google Patents

Description

May 20, 1930.

L. C. STUKENBORG LIFTING JACK Filed July 8, 1927 INVENTOR Zauzls C Sill/(61111049 ATTORNEY Patented May 20, 1930 UNITED STATES.

PATENT OFFICE LOUIS .C. s'ruxmono, OF MEMPHIS, TENNESSEE, ASSIGNOR TO OILDBAULIO LET COMPANY, OF MEMPHIS, TENNESSEE, A CORPORATION OF DELAWARE L'm'rme JACK Application filed July 8,

My invention relates to lifting jacks and more particularly to a hydraulic or fluid pressure Jack.

An object of the invention is to provide a lifting jack which requires but a minimum of pressure to lift and support a maximum load.

Further the invention provides a hydraulic jack wherein fluid is normally contained in an elevating piston which is conducted therefrom and discharged under pressure beneath the piston to elevate the latter, the fluid being conducted back into the hollow piston by the pressure thereof against the fluid head as the piston descends to normal position.

The invention also contemplates a lifting head designed to lift and support wheeled vehicles.

Still another object resides in the provi- .sion of a hydraulic or fluid pressure jack having means for automatically stopping the ascent of the piston when the latter reaches a predetermined point, thus obviating the danger of the piston moving from its cyllnder.

With the preceding and other objects and advantages in mind, my invention consists in the combination, construction and arrangement of parts and objects to be hereinafter specifically referred to, claimed and illustrated in the accompanying drawing, wherein,

Figure 1 is a fragmentary top plan view of a hydraulic jack constructed in accordance with my invention, and

Figure 2 is a vertical sectional vlew of the same.

Referring to the invention a vertical cylinder 5 is provided having a removable bottom cap 6 and equipped with a stufling box? at 1ts upper ends. Reciprocable in the cylinder 5 is a hollow piston 8 having a lower closed wall 9 and which is slidable through the smiling box, and aacking gland 10 secured to the up er end 0 the stufling box.

X lifting head is provided for ralslng and supporting motor vehicles and campuses a central rectangular body 11 having a central opening 12 in its under face into which the upper end of the hollow piston projects so that e body 11 rests directly upon the upper end of the piston.- To receive and support vehicle 1927. Serial No. 204,327.

wheels, channeled shaped tracks orguides 13 upon which an automobile is driven, is provided at opposite sides of the body 11.

In order to support and rigidly brace the track or guides 13 a pair of substantially longitudinal bowed I beams is provided. These I beams have intermediate parallel portions 15 embracing the opposite ends of the body 11 and secured thereto by fastenings 16. AS illustrated in Figure 2 the extremities of the I beams 14 extend laterally beneath the channelled shaped tracks or guides and are electrowelded or otherwise secured thereto adjacent their ends.

Extending vertically through the hollow piston is a fluid conducting pipe 17 having its lower end threaded in an opening 18 in the closed end 9 of the piston to discharge fluid into the cylinder 5. A fluid return pipe 19 also extends vertically through the hollow piston and has a lateral branch 20 at its upper end extending transversely across a vertical opening 21 in the body 11 and communicating with the inlet of a rotary pump 22 driven by an electric motor 24, the pump motor being supported upon a shelf 25 extending from one of the I beams 14 to the adjacent track 13, and a control switch 26 in circuit with the motor is attached to this track. The supply pipe 17 also has a lateral branch pipe 27 at its upper end extending across the opening 23 and communicates with a check valve 28, the latter in turn having communication with the pump outlet.

To control the passage of fluid to either the P y P p 1 valve 28, and leading therefrom is an outlet pipe 30 which, when the valve is in closed position, directs the fluid into the hollow piston. a

An actuating arm 31 is provided with a cylinder or hollow piston 8, athree way valve, 29 is interposed in the branch 27 to the supbetween the latter and the check three way valve, and connected therewith is a longitudinally movablehorizontal actuating lever 32 having one end supported in a bracket or guide 33-upon the under face of one of the tracks 13 ad acent the switch 26.

at a predetermined height a vertical branch In order to stop the ascent of the piston of the piston as it into the piston by way pipe 34 having communication with the pipe With the piston in its extreme lower position as illustrated in Figure 2, the pump being in operation, the valve 29 is opened by manipulation of the handle 4. Vacuum in the pipe 19 reduced by the pump 22 lifts the liquid from the hollow piston directing it under compression into the cylinder 5 by way of the discharge pipe 17 causing ascent the cylinder gradually fills. By reason of the inlet in the branch pipe 34 being above the inner end of the pipe 19, the pump will cease to function as above stated when the liquid in the hollow cylinder re cedes to a predetermined point, the piston being supported in elevated position to retain its head in elevated position by the column of liquid in the cylinder. .To cause the piston to descend the valve 29 is actuated to sever communication between the pump and supply pipe 17 and establish communication between the bleed pipe and discharge pipe.

The bleed pipe belng open pressure is re-.

lieved from the piston allowing it to gravitate forcing the liquid from the cylinder through the discharge pi e and emptying oi the bleed pipe. What is claimed is 1. In a vehicle lifting device of the class described, a stationary cylinder, a piston slidable in' the cylinder, a body rigidly mounted on the upper end of the piston,

means mounted on sald body .and constructed for accommodating and supportinga vehicle,

a motor driven pump on said vehicle supporting means, and valved piping connected with the pump and associated with the piston, said valved piping including a. discharge pipe connected through a valve with the pump, a return pipe extending from the valve, the valve being movable to position for affording communication between the discharge pipe and the pump or another position affording communication between the discharge pipe and the return-pipe and a supply pipe connected with the pump.

2. In a vehicle lifting device of the class described, a stationary cylinder closed at its bottom, and providedat its top with a stufling box, a hollow piston slidable in said cylinder, said piston being closed at its bottom, and open at its top, a body having a socket in its under sidereceiving and closing the upper end of said piston, vehicle supporting means carried by the body, a motor driven pump carried by said vehicle supporting means, and piping connected. with the pump and extending into saidpiston, said piping including a valve to aflord communication between the cylinder and pump'or the piston and pump.

3. In a structure of the class described, a cylinder, a stuffing box at the upper end of the cylinder, cylinder and through said stuffing box, a head supported on the upper end of the piston, a fluid circulating pump on said head, a valved conducting pipe leading from the pump on one side and down through the hollow piston, and communicating at its bottom with said'cylinder for delivering fluid into the cylinder to elevate the piston, a return pipe connected with the other side of the pump and extending down into the piston, and terminating in spaced relation to the bottom of said piston, and a branch pipe communicating with thepiston and the valved conducting pipe, the lower end of said branch pipe terminating above the lower end of said conducting pipe for causing the pump to cease functioning when the liquid in the piston reaches a predetermined point.

4. In a jack structure, a cylinder, a hollowpiston therein forming a reservoir, a pump, a discharge pipe between the cylinder and one side of the pump, a valve in said plpe, a return pipe connected with the valve and adapted to discharge into the piston and a supply pipe between a low point in the piston and the other side of said pump.

' LOUIS G. STUKENBORG.

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