US2489056A

US2489056A - Lifting jack

Info

Publication number: US2489056A
Application number: US656086A
Authority: US
Inventors: Skiler C Stewart
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-03-21
Filing date: 1946-03-21
Publication date: 1949-11-22
Anticipated expiration: 1966-11-22

Description

Nov, 22, 1949 s. c. STEWART 2,489,056

LIFTING JACK Filed March 21, 1946 2 Sheets-Shget 2 2 BY wayraw d.

ATTURN EYB Patented Nov. 22, 1949 UNITED STATE T-ENT- OFFICE 2 Claims. The invention relates to a lifting jack andmore especially to. a wheeled truck jack.

The primary. object of Ithe invention is the provision of a jack of this character, wherein through a toggle acting lift mechanism upon a wheeled carriage, a motor or other vehicle can be raisecl and lowered with ease and dispatch, the height of'liftingcan be-varied and the lift having a maximum range without any possibility of the jack turning over or becoming unbalanced by its load under maximum lift range.

Another object of the invention is the provision of a jack of this character, wherein the construction thereof is novel and the assembly of the parts unique, to assure the maximum of adjustment to give extreme lifting heights thereto in the raising or hoisting of work.

A further object of the invention is the provision of a jack of this character, wherein it is effective as a hoisting or lift crane, and is perfectly balanced at Variable heights or lift, it also being movable from one point to another as it is of the mobile type.

A still further object of the invention is the provision of a jack of this character, which is simple in construction, thoroughly reliable and eflicient in operation, strong, durable, readily and easily operated, possessed of few parts, compact in assembly, conveniently handled with dispatch, and inexpensive to manufacture.

With these and other objects in view the invention consists in the features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawings, which disclose the preferred embodiment of the invention and pointed out in the claims hereunto appended.

In the accompanying drawings:

Figure l is a side view of the jack constructed in accordance with the invention.

Figure 2 is a rear end view of the same.

Figure 3 is a view similar to Figure 1 showing the jack in an adjusted position.

Figure 4 is a top plan view with the jack in position as shown in Figure 1.

Figure 5 is a view similar to Figure 3 showing the jack in an adjusted position.

Figure 6 is a plan view with the jack in the position shown in Figure 5.

Figure 7 is a fragmentary sectional view taken on the line 11 of Figure 6.

Figure 8 is a sectional view taken on the line 8-8 of Figure 5 looking in the direction of the arrows.

Figure 9 is a sectional view taken on the line the arrows.

2 9- 9 of' Figure 7 looking in the direction of the arrows.

Figure 10 is a sectional viewtaken on the line i m of Figure 3 looking. in the-directionof Similar reference characters indicate cor, responding parts. throughout the several views in the drawing.

Referring. to the drawings in detail, the jack constructed in accordance with the invention, comprises a wheeled carriage involving an elongated or rectangular shaped horizontal sill or chassis frame It, having a front extension section ll, its wheels together with the wheels of the frame it being provided with traction and swiveled caster steering wheels I2 and I3 respectively.

The frame It] at the end next to the wheels l3 has rising therefrom a perpendicular handle bar frame l4 having the cross handle rung l5 at an elevation.

At the longitudinal center of the frame l0 and at the end having the handle bar frame I4 is a hydraulic lifter, its upright cylinder it is stationarily mounted on the frame I 0, while its movable lifting plunger ll telescopes within this cylinder and is raised and lowered hydraulically under the control of an actuator hand lever l8. The plunger I! at its upper end carries a crosshead l9 encasing at its outer ends pulleys 20 over which are trained hoisting chains 2|, there being a pair of these, and the same have coupling connections 22 with the frame It] and also coupling connections 23 to a pair of vertically swingable and horizontally slidable beams 24, which are in spaced parallel relation to each other. The beams 24 are joined near opposite ends by cross struts 25, one being a runner on a horizontal guide lodge or track 26 built to the side sills of the frame it at their inner faces.

Arranged between the beams 24 and swingingly connected thereto by a pivot 21 is a jacking rail 28, the pivot being intermediate with relation to the length of such beams and the rail, and the latter connected by a hinge 29 at its inner end to the frame it! next to the end of the latter adjacent to the steering casters thereof.

The outer end of this rail is equipped with a swivel rest fitting 30 while telescopically engaged in such rail is slidable extension rail section 3|, which has an outer hook end 32 thereto, and by this extension rail section the rail can be lengthened or shortened, as may be required for vertical height lifting quality.

The rail 28 is provided at its outer end with an 3 underslung latch device 33 which can engage the frame ill to hold them together when in a horizontal plane with one another, when the rail has been completely lowered on the marriage The height of swing of the lift rail 28 can be altered by extending the rail section 3i, as best seen in Figure 5 of the drawings, while to prevent the tipping over of the carriage the frame extension section i I can be projected from the frame l0, so that the load will be properly balanced, this being also best seen in said Figure 5. The lifter is operated to raise and lower the jacking rail 28 and its extension rail section 3|, which is latched by the latch device 33 in an extended position. To shorten the throw of the jacking rail beams 24 are automatically adjusted by the lifter, including the cylinder l6 and plunger l1 respectively.

What is claimed is:

1. A structure of the kind described, comprising a wheeled carriage including a pair of horizontally extending hollow side members of rectangular cross section, vertically swingable and horizontally shiftable hoisting beams on the carriage, a jacking rail pivoted to the carriage and to the beams and regulated by movement of the latter, and an adjustable extension for the car riage including a pair of I-beams each slidably mounted in one of said hollow members,

2. A structure of the kind described, comprising a wheeled carriage including a, pair of horizontally extending hollow side members of rectangular cross section, vertically swingable and horizontally shiftable hoisting beams on the carriage, a jacking rail pivoted to the carriage and to the beams and regulated by movement of the latter, an adjustable extension for the carriage including a pair of I-beams each slidably mounted in one of said hollow members, and an extensible section for the jacking rail and a latch for holding the same in adjusted positions.

SKILER C. STEWART.

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

UNITED STATES PATENTS Number Name Date 188,846 Bengger Mar. 27, 1877 1,410,103 Lightner et a1 Mar. 21, 1922 1,553,074 Engel Sept. 8, 1925 FOREIGN PATENTS Number Country Date 342,488 Great Britain Feb. 5, 1931