US569585A - Lifting-jack - Google Patents

Description

(No Model.)

` C. 'I'. MOORMAN.

Patented oct. 1a, 1896,

UNITED STATES i CHARLES T. MOORMAN,

PATENT OEEICE.

OF PACKWOOD, IOVA.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 569,585,7dated October 13, 1896. Application led August 28, 1895. Serial N0- 560,77 8. (No model.)

To @ZZ whom t may concern:

Be it known that I, CHARLES T. MOORMAN, a citizen of the United States,residin g at Packwood, in the county of Jefferson and State oi' Iowa, have invented certain new and useful Improvements in Lifting-Jacks; andI do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improvement in lifting-jacks; and it consists in the construction and arrangement of parts hereinafter described, and deiinitely pointed out in the claims.

The aim and purpose of the invention are the provision of improved means for actuating the jack and adjusting; the lifting-arms to engage the axle before the lifting or elevating is eiected. These objects are attained by the construction illustrated in the accompanying drawings, wherein like letters of reference designate corresponding parts in the several. views, and in which- Figure l is an elevation of the jack. Fig. 2 is a vertical section. Fig. 3 is a similar view, showing the parts in a different position. Fig. 4c is a rear elevation of the levers shown in connection with the front section of the frame. Figs. 5 and 6 are detail views of the levers referred to as the link, T- head, and pawlg and Fig. 7 is a fragmentary view of the lifting-bar E, the rack f, and spring G.

In the drawings, A designates the frame, having the base B and enlarged section C. The frame has a central vertical channel D, in which the lifting-bar E is loosely mounted. This bar carries on its lower end the oppositely-extending lifting-arms F, projecting through suitable elongated slots d, formed in the frame. At its upper end the bar is formed with a rack f, having inclined teeth, the inclination being on their upper edges only. Below the rack the bar is out away, as at f.

F' designates a hand-knob secured to the bar at its upper end and extending through an elongated opening a' in the frame.

The side wall of the channel D is cut away, as at d', and anat spring Gr is secured to the wall and extends over the cut-away portion thereof. Its upper end is formed with a lip g, which moves in a groove g and normally rests against the iiange g2.

The actuating mechanism comprises a handle or lever H, which carries at its inner end a T-head II', formed with curved elongated slots h h in its opposite ends. Adjacent to the inner walls of the slots are the lateral pins h2 h3, and centrally of the head on the opposite 'side is a lateral pin h4, which projects into the vertical slot a2, formed in the enlarged section of the frame.

I designates the fulcrum -linlr, which is formed with the oppositely-cnrved slots 't' t" in its lower end and the intermediate conicalshaped slot t2. In the front section of the frame are secured turn-pins t3 'i4 t5, passing through the slots, the former and latter being substantially in a horizontal line, while the central one is on a plane slightly above the others. By this means a limited rocking movement is allowed the link, and the pivotal center or fulcrum is successively changed from one pinto the other, so that the upper end of the link will move in substantially a straight line instead of in a true arc. The upper end of the link I has a curved slot I therein, and from its rear face extends a pin i, which engages in the slot h of the handle, and the pin h2 engages in slot I.

K designates the pawl member, which has a curved slot k in its lower end and a lateral pin 7c slightly above the slot. The pin enters the slot h of the lever, while the pin 71,3 of the lever enters the slot 7a. The upper end of the pawl has a pin k2, which constitutes the tooth and works in the cut-out portion of the lifting-bar and when the parts are actuated engages the rack-teeth.

In operation the lifting-bar is drawn up through the medium of the hand-knob, and as the lifting-arms engage the axle the tooth of the pawl member engages the rack and retains the bar in its elevated position. The handle is then forced down, which raises the T-head from a horizontal to a perpendicular position, elevating the pawl, which in turn elevates the lifting-bar. The downward movement of the handle is continued until the T-head is slightly inclined in an opposite direction, or beyond the pivotal center, and

IOO

vthe parts lockedfrom downward movement. As the handle Ais lowered the fnlcrum-link moves so as to shift its fnlcrum from the pin to pin directly below the central pin h, which allows a vertical movement only, and by the various curved slots and the interchanging pins the pivotal action or movement of each member is shifted from one center to another, thereby diminishing the extent of movement while maintaining substantially the leverage and vertical movement of the parts. Then the axle is to be lowered, it is only necessary to throw the parts off from the dead-center or lock and by its own weight the same will fall, the pressure on the handle preventing too sudden movement.

To permit thelifting-bar to descend or pass the pawl, the handle is raised to its limit, as shown by dotted lines in Fig. 4, and by the limited pivotal movement of the pawl caused by the pins and slots 7L the pawl is forced against the spring, out of engagement with the teeth of the rack.

By the special arrangement of the various levers it will be seen that a short movement of the handle will eiect a relative extended movement of the pawl member, and by the curved. slots and pins, arranged as described and shown, the movements of the partsv are in substance or practically vertical as the fulcr ums are changing during the movement, that is, shifted laterally.- The leverage is by this means not diminished to any extent, but the effect of a long leverage is obtained through the instrumentality of the short levers, (link, T, and pawl.) The effect, primarily, is a relative greater upward movement of the lifting-bar with a short movement of the handle.

Having thus described the invention, what is claimed asnew, and desired to be secured by Letters Patent, is-

1. In a lifting-jack, the combination with a frame, of a lifting-bar slidingly secured in the frame, a handle having a T-head rigid therewith, a fulcrum-link pivotally connected to the head, and a paWl connection between the bar and the T-head, substantially as described.

2. In a lifting-jack the combination with a frame, of a lifting-bar slidingly supported therein, a handle having oppositely-extending projections at its inner end, a fulcrumlink, shifting connections between the link and frame and between the link and a handle projection, a pawl having a shifting pivotal connection with the other handle projection, a rack on the lifting-bar, and a spring for normally forcing the pawl into engagement with the rack, substantially as described.

3. In a lifting-jack, the combination with a frame, of a vertically-movable lifting-bar, a lever mechanism for raising the bar com,- prising a fulcrum-link having a shifting connection with the frame, a hand-lever having a shifting connection with the upper end of the link, and a vertically-movable pin passingthrough the frame, a pawl having a shifting connection with the handle-lever, and a spring for normally forcing the pawl into connection with the lifting-bar, and a projection on the lifting-bar for raising the saine independent of the lever mechanism, substantially as described.

In testimony whereof I aiiix my signature in presence of two witnesses.

CHARLES T. MOORMAN.

lVitnesses SILvANUs. KOERNER, J. S. LOUGHARY.

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