US249235A - Lifting-jack - Google Patents

Description

(No Model.) 2 She'ets-Sheefi 1.

H. R. FERRIS.

LIPTING JACK. A No. 249,235. Patented Nov'.8,1 881,

N, PETERS, Phqto-Limgnphar, Wnhingion. u. c.

2 t e on h ab m flu e h S 2 I Rm m e N fl RF M H (No Model.)

No. 249,235. Patented NOV. 8, 1881.

% INVENTOR I r -ogfi ATTORNEYS" UNITED STATES PATENT OFFICE.

HIRAMB. FERRIS, or CLEVELAND, onto.

.LlFTlNG-JACK.

SPECIFICATION formingpart of Letters Patent No. 249,235, dated November 8, 1881 To all whom it may concern:

Be it known that I, HIRAM R. FERRIS, of Cleveland, in the county of Guyahoga and.

State of Ohio, have invented certain new and useful Improvements in Lifting-Jacks; and I do hereby declare the following to be a full,

clear, and exact description of the invention,

My invention relates to lifting-jacks; and

it consists in the peculiar construction of the same, as will be hereinafter fully set forth and claimed.

In the drawings, Figure l is a side elevation of my jack. Fig. 2 is a vertical cross-section of the head and grasping device of the same. Fig.3 is a view of the head with part removed,

showing the grasping device within said head,

and in a closed position. Fig; 4 is also a view of the head with part removed, showing the grasping device in an open position, and the device for locking said grasping device in said open position. Figs. 5 and 6 are sectional views, showing different constructions of the jaws of the grasping device.

A is a post or standard, which is made hot low for the reception of the lifting-shaft.

B is alifting-shaft, which is constructed to have a vertical movement, and is provided at its top with a suitable bearing-surface, B, and at its lower end with a hooker lug, B which extends out from the side of the standard, and isparticularly adapted to be used to raise rails and such like low weights. The liftingshaft.

B has formed upon. it a ratchet screw-thread, which is preferably mutilated, as shown in Fig. 1, by having two slots cut through it, said slots being opposite each other, thus forming two ratchets, O 0, (shown more clearly in Fig. 2,) one on each side of the shaft B.

D is a head, which surrounds the shaft B. This head D contains the grasping device for raising the shaft B, said grasping device being co iiposed of two jaws, E and E, which act as pawls and engage with the screw-thread or ratchets O C. I preferably construct the jaws E and E as shown in Figs. 2, 3, and 4, viz: I provide the upper and lower ends of the interior of the head D with inclines a, 12,0, and d,

Application filed September 21, 188i. (No model.)

on which rest the inclines at the-upper and lower ends of the jaws E and E, and thus it will be seen that'the gravity of the jaws E and E willact to draw them toward the shaft B and cause them to engagewith the thread or ratchets G O, and that the more the head D is forced upward the tighter will the jaws E and E hug the shaft B. This is also true of the construction shown in Figs. 5 and 6, which will be easily understood from the said drawings without any further description.

F is" a nut, which is adapted to turn on the shaft B, and is placed between the head D and standard A. The ofiice of this nut is to hold the shaft B-at any desired point by bearing against. the top of the standard A. To the head D are attached toggle arms or links G and G, said toggle-arms beingalso connected to the short arm of the lever H. The lever H is pivoted at f to the standard A.

I is a locking device, which is placed between thejaws E and E, and, being operated by the lever J, acts to lock the jaws E E open and allow the shaft 13 to pass freely between them.

(See Fig. 4.) Fig.3 shows the position of the locking device I when it is not desired to lock thejaws E and E open. i The operation of my device is as follows: The shaft B is held up by means of the nutF,which rests on the top of the standard A. .The long arm of the lever H is lifted, which acts through the links G and G to lower the head D. As the head D islowering, the teeth on the jaws E and E slide over the ratchet screw-threadO and G on the shaft B, which causes the said jaws E and E to open, as shown in Fig. 4, and allows the head D to lower, the shaft B being held in position by means of nut F. When the head D has been lowered sufficiently theleverH is brought down, which acts to force thehead D up. Now, as the head D is forced upward, the jaws by their gravity close in toward the shaft B and engage-with the ratchet-teeth O and G, and the shaft B is raised as far as the short arm of the lever H will raise it. As the shaft B is raised it carries with it the nut F, and this nut F is now run downward until it rests on the top of the standard A, where it again acts to support the shaft B, while the head D is again lowered, as above described. This operationis repeated until the weight is raised thc-desired distance. To lower a weight the operation is reversed.

When no weight is on thejack, and it is desired to lower the shaft B, the look I is brought into service, asshown in Fig. 4, and locks the jaws open, when, the shaft B being held upby one hand, thenut F may berun up by the other, and thus the shaft B may be quickly lowered.

What I claim is 1'. In a lifting-jack, the combination, with a lifting-shaft provided with ratchet-teeth on opposite sides thereof, of graspingdevices ,located on each side of the lifting-shaft, and adapted to automatically engage the teeth thereon, an actuating-lever, and devices connecting the lever and grasping .devires,substantially as set forth.

2. In a lifting-jack, the. combination of. a shaft, B, having a screw-threadand a supportingvnut, F, with a head, D, said head having a grasping device adapted to engage with the said screw-thread, andbein g operated by means of a lever, B, substantially as shown and described.

3. In a lifting-jack, the head 1), said head having the inclinesa, b, c, and d, and the jaws E and E, said jaws being also provided with inclines adapted to rest on the inclines a, b, c, and d, substantially as and for the purpose shown and described.

4. In a lifting-jack, the combination, with a lifting-shaft provided with teeth on its opposite sides, of two grasping devices locatedon each side of the lifting-shaft, the locking dcvice I, and lever J, substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

. HIRAM R. FERRIS.

Witnesses:

JNo. ORoWELL, Jr., W. E. DONNELLY.

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