US2535759A - Hydraulic bumper jack - Google Patents

Description

Dec. 26, 1950 J, C, SQHWANTNER 2,535,759

HYDRAULIC BUMPER JACK I u ver/tor DCC- 25, 1950 J. c. scHwANTNER HYDRAULIC BUMPER JACK '2 Sheets-Sheet 2 Filed Sept. 25, 1945 Inventor fo-$6796 Car? Schl/e222" 71er Patented Dec. 26, 1950 HYDRAULIC BUMPER J ACK Joseph Carl Schwantner, Chicago, Ill., assigner of one-half to Helen Schwantner, Chicago, Ill.

Application September 25, 1945, Serial No. 618,525

1 Claim.

This invention relates to a `bumper jack and more particularly to a lifting jack for elevating a motor vehicle to facilitate the changing of tires and similar operations.

The primary object of the invention is to enable a vehicle of the automotive type to be elevated so that one or more of its `Wheels may be moved clear of the ground so that various operations may be performed thereon.

Another object of the invention is to facilitate the elevation of the vehicle with ease through the use of hydraulic pressure, and to prevent the building up of too great a pressure when the jack has attained its greatest height.

Among its features, the invention embodies a vertical column carrying, at its upper end, a piston and at its lower end a liquid reservoir, a cylinder slidable on the piston, and means to force liquid from the reservoir through the piston and into the cylinder to elevate the latter.

Other features include an adjustable hook carried by the cylinder for engagement With a portion of the frame, such as the bumper of the vehicle to be elevated, a manually controlled valve for establishing communication between the interior of the cylinder and reservoir to permit the lowering of the jack and the load imposed thereupon under controlled conditions, and an automatic release valve operated by the cylinder to return the iluid to the reservoir when the Y cylinder has attained its greatestheight on the piston. i

In the drawings- Figure 1 is a view of a bumper jack embodying the features of this invention, certain portions thereof being shown in section to more clearly illustrate the details of construction,

Figure 2 is a horizontal sectional View taken substantially on line 2-2 of Figure 1,

Figure 3 is a fragmentary side View of the upper end of the cylinder showing the adjustable hook,

Figure 4 is a horizontal sectional View taken substantially on the line 4-4 of Figure 1,

Figure 5 is a, horizontal sectional view taken substantially on the line 5--5 of Figure 1,

Figure 6 is a sectional View taken substantially on the line 6 5 of Figure 5, and

Figure 7 is a fragmentary enlarged sectional view through the piston and cylinder.

Referring to the drawings in detail, my improved jack, designated generally lll, cornprises a tubular column il provided, at its upper end, With a head I2 carrying a suitable packing l 3 to form a piston. The head l2 is formed with a concentric bore I .4 into which the upper end of a vertically extending, concentric pipe l5 is anchored in any suitable manner. Welded or otherwise secured to the lower end oi the tubular column ll is a reservoir l5, and the lower end of the pipe l5 extends to the bottom of the reservoir, as vvill be readily understood upon reference to Figure l. Welded or otherwise secured to the column ll intermediate its ends is a spider l'l to Which stabilizing legs lil are pivotally attached, as at i9. As illustrated in Figures l and 6, the lower end of the pipe l5 is closed and formed adjacent the lower end thereof is a transverse bore 25 which terminates axially of the pipe in a verticalbore, the upper end of which is formed with altaperedvalve seat 2| which opens into the bore in the pipe' l5 and is adapted to receive a ball check valve 22 which serves to prevent iluid entering the pipe through the bore 2l! from iiowing in a reverse direction. Formed in the pipe l5 above the ball valve 22 is a radial tapered passage 22 which forms the seat for a needle valve '23 operable through a suitable packing gland 25 in the side Wall of the reservoir l5 by means of a hand Wheel 25. It will thus-be seen that liquid entering the column through the transverse bore 2@ may be returned to the reservoir I5 by manipulation of the needle valve 23, Formed on the inner face of the Wall of the reservoir I5 is a pump case 26 provided with a vertical bore 2l in which, a piston 28 is mounted for reciprocation. The lower end of the bore 2 communicates through a transverse `bore V2li with a suitable pipe 35, the opposite end of which opens into the bore 2li so that as the piston 28 is reciprocated Within the bore 27, the fluid from the reservoir taken into the bore 21 through a suitable check valve 5I will be ejected through the pipe Sie and into the pipe I5 through the ball valve 22. Pivoted at 33 to the column ll above the upper end of the reservoir l5 is a lever 35 to Which the upper end of the piston rod 35 carried by the piston 28 is pivoted, as at 35. This lever is provided with a socket 3l into Which a handle 53 is adapted to be fitted to facilitate the operation of the pump mechanism just described.

Mounted for vertical sliding movement on the head l2 is a cylinder 39, the upper end of which is closed, as at 45, to form a chamber il within the cylinder into which the fiuid flowing through the pipe I5 is introduced for causing the cylinder to move` vertically on the head l2. Threaded or otherwise secured to the lower end of the cylinder 39 is a guide ring 42 which cooperates with the column II in preserving the cylinder in proper alignment on the column I I.

Formed in the head I2 parallel with but offset from the bore I4 is a bore 43 formed at its upper end with a valve seat 44 and having communicating therewith a passage 45, the opposite end i which opens into the interior of the column II around the pipe I5. The lower end of the bore 43 is closed by anfapertured plug 46 in which the stem of a valve 41 is slidably mounted in such a manner that the lower end thereof projects below the general level of the underside of the head I2, and in the path of the ring 42 so that when the cylinder 39 is moved to its highest point of elevation, the stem or the valve 4l will be engaged by the ring 42 so as to unseat the Valve and establish communin cation between the chamber 4I and the reservoir I6.

Mounted for vertical adjustment on the cylinder 39 is a clamping ring 48 to which a suitable suspension hook 49 is attached. This hook may be formed directly upon the ring 43 if so desired, but I nd it preferable lto arrange for its self-alignment by providing the ring 4S at diametrically spaced points with pivot pins or trunnions 50 to which an intermediate ring 5i is pivotally attached. The ringflcarries, at diametrically opposed points and arranged on axes perpendicular to the axes of the trunnions o 50, radial pivot pins or trunnions 52 upon Whichan outer ring 53 carrying the hookLlQ is pivotally attached. It will thus be seen that the Yhook 49 may be mounted for universal motionon the ring 48 so as to automaticallyadjust itself to proper position beneath a bumper when the jack is in use.

In operation, it will be understood that 4the jack is positioned in approximately proper relation beneath the bumper of a vehicle with the legs I8 extended, as illustrated in Figure 1, so as to lend stability to the structure. The legs I8 are of such length that theyserve to sustain the weight of the jack as well as to lend stability to the column II and Vhaving positionedfthe jack. beneath the bumper-of the vehicle to be lifted, the valve 23 is closed and the lever 31 is manipulated to cause the piston 28 to reciprocate with-` in the cylinder 27. Reciprocation of the piston causes the liquid to flow through the valve 3i and into the cylinder 27 and thence out through the pipe 30 and into the pipe I5 through the ball check valve 22. The fluid rising in the pipe I enters the chamber 4I through the head I2 and thus exerts a lifting pressure on the cylinder 39. This causes the hook 49 engaging* the bumper to rise and consequently lift the weight of the vehicle. In order to prevent too great a pressure being developed Within the chamber-4I when the cylinder has risen to its upper limits,

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4 the valve 4'! vis brought into play by engagement of the ring 42 with the stem of said valve, thus opening the latter and establishing communication between the chamber 4I and the reservoir I5 through the space within the column II surrounding the pipe I5. When it is desired to lower the jack and the load carried thereby, the hand wheel 25 is rotated to open the valve 23 so vas to establish communication between the interior of the pipe I5 and the reservoir I6 and permit rthe iluid to return from the interior of ythe cylinder to the reservoir under controlled conditions.

While in the foregoing there has been shown and described the preferred embodiment of this invention, it is to be understood that minor changes in the details of construction and combination and arrangement of parts may be resorted to Without departing from the spirit and scope of the invention as claimed.

What I claim is:

In a hydraulic jack, a liquid reservoir, a tubular column extending vertically from the reservoir, the lower end of the tubular column opening into the reservoir, a piston carried by and closing the upper end of the tubular column, a cylinder mounted on the piston to slide verticali'` means extending axially through the piston to feed liquid under pressure upwardly into the cylinder above the piston, said piston having a passage therein opening through its top and into the'interior of the column, a check Valve in the passage to arrest the ow of liquid through the passage from the cylinder to the column, a Valve stern on the check valve and extending through the-bottom of the piston and guide means on the cylinder and encircling the column to guide the cylinder as it moves on the piston 'and to engage the valve stem and open the check valve when the cylinder reaches a predetermined height on the piston.

JOSEPH CARL SCHWANTNER.

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

UNITED STATES PATENTS Great Britain Mar. 30, 1933

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