US1213376A - Lifting-jack. - Google Patents

Description

H. H. HUFFMAN.

LIFTING JACK.

APPLHIATION HLED SEPT. 20. 1916.

Patented J an. 23, 1917,

HenryHHuffman A n HENRY II. HUFFMAN, OF COLUMBUS, ()HIO.

LIFTING-JACK.

Specification of Letters Patent.

Patented Jan. 23, 1917.

Application filed September 20, 1916. Serial Ito. 121,177.

To all "whom it may concern Be it known that I, Henry H. ITUFFMAN, acitizon of the United States, residing at Columbus, in the county of Franklin and State of Ohio, have invented a certain new and useful Improvement in Lifting-Jacks,

of which the following is a specification.

The principal object of this invention is to provide a lifting jack of simple and economical construction in which the lifting bar can be lowered either slowly or quickly according to requirements in use.

The invention is embodied in the example herein shown and particularly set forth, the features of novelty being finally claimed.

In the accompanying drawing, Figure 1 is a view in side elevation with a portion of the base broken away to show the position of the operating bar in the ordinary lifting operation. Fig. 2 is similar View showing one position of the parts when the lifting bar is being lowered step by step. Fig. 3 is a similar but fractional view showing the position of the parts when the lifting bar has been lowered a tooth in the lowering op eration. Fig. i is a similar but fractional view showing the position of the parts when the lifting bar has been quickly lowered.

The jack includes a base or stand 5 having pivoted to its front portion a pawl 6 to engage the teeth of the-lifting bar 7. As usual, the lifting bar 7 slides vertically in a suitable socket in the base, said bar being provided with a toothed edge 8 and head 9 that, if desired, may be swiveled to the upper end of the ban The lifting bar also has projecting from its edge a supplemental load rest 10.

For its proper operation the structure includes an operating bar 11 having at one end two teeth 12, 12 extending substantially parallel to each other and in the instance shown in a direction parallel to the length of the operating bar and at the other end a single tooth 13 standing at an angle to the said length. Near each end of the operating bar is a pair of trunnions like that shown at 14 to rest in bearings or fulcrums 15 in wings 16 at the upper portion of the forward edge of the base. These wings have parallel openings 17 leading to the bearings so that the trunnions at either end of the operating bar can be inserted and moved therein according to the end of the operating bar to be used in working the lifting bar.

The pawl 6 has a weighted arm 18 extending rearward tending to hold the end of the pawl inward toward the toothed or racked edge of the lifting bar. Said pawl also has a forwardly extending finger 19 adapted to be depressed bf the operating bar or by a projection 20 thereon according to which end is used to operate the lifting bar. The inner portion ofthe finger 19 has a depression, as at 19. The projection 20 of the operating bar has a hole in which is loosely fitted a pin 91. Said pin can be suitably headed where necessary to prevent it from dropping out of the hole.

The lifting bar 7 can be raised with either end of the operating bar. lVhen that end of the operating bar having two teeth is used to raise the lifting bar the other end of the lifting bar should be raised and the upper tooth inserted under the proper tooth as shown in full lines Fig. 1 with the projection 20 on the operating bar uppermost. lVhen the lifting bar is to be slowly lowered the operating bar should be inserted in a nearly horizontal position with the projection 20 lowermost so as to embrace the proper tooth. Then by depressing the operating bar until the pin 21 enters the depression 19 the pawl is actuated to fetch it into position, as shown in F 2, to permit a tooth or teeth of the lifting bar to pass the end of the pawl, as shown in Fig. 3. In this operation the pin 21 retains the pawl in removed position sufliciently long to'permit the lowering of the lifting bar one or more teeth with a step by step mo ement. To secure a quick lowering of the lifting bar that end of the operating lever bearing the single tooth is employed. This end is inserted in any posi tion where it can take a tooth and then the other end depressed until the pawl and said tooth are removed from engagement with the lifting bar whereupon the lifting bar will completely fall under its load, as shown in Fig. 4;.

Vhat I claim is:

1. A lifting jack comprising, in combina tion, a base. a lifting bar having a toothed edge, a pawl and means for causing the same to be automatically engaged with said toothed edge. an operating bar constructed to engage said toothed edge to raise and lower the lifting bar and to directly actuate the pawl to remove the same from engagement with said lifting bar, and an automatically sliding device on the operating bar for engaging said pawl and holding the pawl disengaged from the lifting bar when the operating bar is moved to lower the lifting bar.

A lifting jack comprising, in combination, a base, a lifting bar having a toothed ed e, a pawl and means for causing the same to be automatically engaged with said toothed edge, said pawl also having a finger with a depression therein, an operating bar eonstrlmted to engage said toothed edge to raise and lower the lifting bar and to directly actuate the pawl to remove the same from engagement with said lifting bar, and

a sliding pin on the operating bar to drop into said depression. to hold said pawl disengaged from the lifting bar when the operating bar is moved to lower the lifting bar.

A lifting jack comprisin in combination, a base, a lifting bar having a toothed edge, a pawl pivoted in the base to engage said toothed edge, means for causing the same to be automatically engaged therewith, and an operating bar having trunnions to fulcrum in the base above the fulcrum of the pawl and having at the same end a single rigid tooth. to engage a tooth of the lifting bar, the other portion of said bar forming a handle and. constructed to engage the pawl, when depressed, to release the same from engagement with the lifting bar, said tooth standing, when the bar is in operative position, at an upward inclination to the axis of the operating bar, whereby the said tooth may be disengaged from the lifting bar and the said handle subsequently depressed to Contact with the pawl to release the same from the lifting bar thereby permitting the lifting bar to fall.

HENRY H. HUFFMAN.

Gonies of this patent may be obtained for five cents each by addressing the Commissioner of Eatents, Washington, D. G.

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