US762841A - Lifting-jack. - Google Patents

Description

No. 762,841. PATENTED JUNE 14, 1904. J. R. PEARSALL;

LIFTING JACK.

APPLIOATION nun rnn. 11, 904.

NO MODEL.

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Patented June 14, 19041 PATENT OFFICE.

J AMES R. PEARSALL, OF SYRACUSE, NEW YORK.

Ll-FTlNG-UACK- SPECIFICATION forming part of Letters Patent N0. 762,841, dated June 14, 1904. Application filed February 11 1904. Serial No. 193,096. (No model.)

To all whom it may concern:

Be it known that 1, JAMES R. PEARSALL, of Syracuse, in the county of Onondaga, in the State of New York, have invented new and useful Improvements in Lifting-Jacks, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description;

This invention relates to improvements in lifting-jacks of the class commonly known as wagon-jacks. i

My object is to produce a simple, strong, and durable lifting-jack in which most of the parts are formed from iron or steel carried in stock, whereby I am enabled to produce a lifting-jack at a minimum cost.

Another object is to provide the lifting-bar with a holding-pawl having opposed nibs or biting edges for holding the pawl in its adjusted position without notching or form-ing teeth upon the lifting-bar.

Another object is to provide yielding means whereby the nibs are held in contact with the opposite edges of the lifting-bar, so that the holding-pawl will remain in any of its adjusted positions and at the same time may be readily moved by hand along. the lifting-bar.

Other objects will be disclosed in the foll'ow-. ing description.

In the drawings, Figure 1 is a side elevation of a lifting-jack embodying the Various features of my invention. Figs. 2, 3, and 4 are sectional views taken, respectively, on

lines 2 2and 3 3, Fig. 1, and 44, Fig. 3. Fig. 5 is a View similar to Fig. 4, showing a modified means for retaining the holding-pawl in its adjusted position; and Fig. 6 is asectionalview on line 6 6, Fig. 1.

Similar reference characters indicate corresponding parts in all the views.

In carrying out the objects stated I provide a circular flat base 1 of metal having a central upright standard 2, which is provided with a central vertical guide-opening 3 extending therethrough fromtopto bottom and through the bottom ofthe base 1, the base and stand ard being usually made of cast-iron and are therefore formed integral with each other. A lifting-bar 4, of stock metal, such as steel,

, is movable vertically, and its lower end is supported and guided in the opening 3 in the standard 2, said bar being extended a considerable distance above the standard, and its op- I posite faces and edges are substantially smooth l and bar 4. The opposite arms of the clip 5 'are disposed at opposite sides of the bar 4,

and their free ends extend laterally beyond the adjacent upright edges of the lifting-bar land standard 2 and receive a pivotal bolt 7.

; A lever 8 is pivoted to thebolt 7 in the open side of the clip 5 and normally extends later- 1 ally and upwardly from said clip along the lifting-bar 4.

A link 9 is pivotally connected at 10 to suitable ears 11 on the base 1 at one side of the standard 2, and its upper end is pivotally connected at 12 to the lever 8 outside of but in close proximity to the pivot 7, and when the lever is in its normal upright position this pivotal connection 12 is located in substantia-l-ly the same horizontal plane as the pivot 7 and is capable of movement through an arc of substantially ninety degrees to a point just inside of a vertical line drawn through the axis of the pivot 7, and when in this position the upper end of the link 9 abuts against the adjacent face of the standard 2, this being the lifting position, and it is evident that when the lever. is rocked to this position the lifting-bar is locked in its adjusted positionfrom downward movement by reason of the fact that the fulcrum 12 and pivot 7 are in substantially the same vertical plane.

A holding-pawl 13 is mounted upon and movable lengthwise of the lifting-bar 4 and consists of a metal U-shaped clip 14 and a flat metal plate 15, inserted in the open side of the U-shaped clip 4 and secured thereto by suitable fastening means, as rivets or bolts 16. The clip 14 preferably consists of a strip of steel, which is fitted around three sides of the lifting-bar 4, with its open end extending beyond the adjacent edge of the bar 4:, and

receives the part 15. The portion of the clip which unites its opposite arms is disposed'at an acute angle with said arms for forming a biting edge or nib 17 to engage one edge of the lifting-bar 4, said nib being at the upper edge of the clip, while the lower portion of.

' the base of the clip stands out some distance .L posed at an angle other than a right angle with its upper and lower edges and are substantially parallel with each other for forming nibs or biting edges 22, the object in having these end faces at an angle with the edges being to permit the stock to out without waste and to make the part 15 reversible, so that if one nib wears blunt the part 15 may be detached from the clip and reversed to use the other nib, and it will be noted that both ends are provided with a pair of apertures 23 for receiving the clamping-bolts 16. The spring 19 is in frictional contact with the adjacent edge of the lifting-bar and tends to tilt the outer end of the holding-pawl down w ardly,so

as to bring both of the nibs 17 and 22 into.

contact with the adjacent edges of the lifting-bar, whereby said pawl is held in its adjusted position.

In Fig. 5 I have shown a modified form of spring 25 for holding the pawl in its adjusted position, said spring being mounted upon a pin 26 and having one end engaged with the adjacent face of the lifting-rod and its other end bearing upon the upper face of the bar 15, and also operates to tilt the outer end of a the pawl downwardly to bring the nibs 17 andl22 into engagement with the edges of the lifting-bar.

It now appears that the clips 5 and 14 project in opposite directions from the liftingbar and that the fulcrum 12 of the lever 8 moves from a normal point in substantially the same horizontal plane as the pivot 7 to a point slightly inside of a line drawn through the pivots 7 and 10 when the bar is elevated to its limit, whereby said bar and lever are automatically locked and held in operative position until the operator returns the lever sufficient tobreak the toggle-lock.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is

1. In a lifting-jack, the combination with a base and hollow standard rising therefrom, of

a lifting-bar guided in the standard, a link pivoted to the base and projecting upwardly therefrom, a lever fulcrumed on the upper end of the link and pivotally connected to the bar, a holding-pawl slidable on the lifting-bar and provided with opposed nibs engaging the opposite edges of the lifting-bar and yielding means interposed between the holding-pawl and lifting-bar for forcing said nibs into engagement with the bar.

2. In a lifting-jack, the combination with a supportingbase and standard rising therefrom, of a lifting-bar guided in the standard, a lever operatively connected to raise and lower the bar and a holding-pawl on the bar comprising a U-shape clip fitted around three sides of the bar, the upper edge of the uniting end of the clip forming a nib to engage the adjacent side of the bar,'and a metal plate inserted between the arms of the clip at the opposite side of the bar and having its opposite ends disposed at an angle other than a right angle with the upper and lower faces of the plate for forming nibs and permitting the plate to be reversed, and means to clamp said plate to the clip.

3. In a lifting-jack, the combination with a supporting-base and standard rising therefrom, of a lifting-bar guided in the standard, a lever operatively connected to raise and lower the bar and a holding-pawl on the bar comprising a U-shape clip fitted around three sides of the bar, the upper edge of the uniting end of the clip forming a nib to engage the adjacent side of the-bar, and ametal plate inserted between the arms of the clip at the opposite side of the bar and having its opposite ends disposed at an angle other than a right angle with the upper and lower faces of the plate for forming nibs and permitting the plate to be reversed, and means to clamp said plate to the clip and friction means engaged with the clip and with the bar to retain the pawl in its adjusted position.

4. In a lifting-jack, the combination with the base having an upright standard having a vertical opening therethrough, a lifting-bar guided in the opening, a link pivotally con-- nected to the base and rising therefrom above the standard, a U-shape clip secured to the bar above the standard, a lever fulcrumed on the upper end of the link and pivotally connected to said clip whereby the bar may be raised and lowered an d a holding-pawl ad justable vertically on the bar above said clip, said holding-pawl comprising a U-shape clip and a plate secured to the latter clipand having its opposite ends beveled to form a nib on each end to engage one edge of the bar, the closed end of the clip being inclined at an angle with the adjacent edge of the bar and also provided with a nib for engaging said adjacent edge of the bar.

5. In a lifting-jack the combination with a base and standard having a vertical opening, a lifting-bar guided in the opening and having its opposite edges smooth and parallel, a U-shape clip slidable on the lifting-bar and having its closed end disposed at an angle with the bar to form a biting-nib at the top engaging one end of the bar, a plate secured in the open side of the clip and having its inner end beveled to form a biting-nib at the bottom engaging the opposite edge of the bar, a link pivoted to the base, and a lever fulcrurned on the link and connected to the lifting-bar to raise and lower the same.

In Witness whereof I have hereunto set my hand this 8th day of February, 1904.

JAMES R. PEARSALL.

Witnesses? H. E. CHASE, AMIE MALCOMB.

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