US599536A - Vania - Google Patents

Description

(No Model.) 2 sheets-sheet 1.

J. A. STARRETT 8v E. F. WELSH.

LIFTING JACK.

No. 599,536. l. Patented Feb. 22,1898.

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A 0017.31? MS/v.

. v v "i hmmm (No Model.) 2 Sheets-Sheet 2.

J. A. STARRETT 8v E. F. WELSH.

LIFTING JACK.

No. 599,536. Patented Feb. 22,1898.

ihvrrnn Frarnt JACOB A. STARRETT AND EDWIN F. WELSH, OF VILMERDING, PENNSYL- VANIA, ASSIGNORS OF ONE-TWENTIETII TO IVILLIAM F. IVOOD, OF

SAME PLAGE.

LIFTINGNJCIK.

SPECIFICATION forming part of Letters Patent No. 599,536, dated February 22, 1898.

Application tiled October 5, 1897.

T0 @ZZ whom t may concern.-

Be it known that we, JACOB A. STARRETT and EDWIN FVELSH, citizens of the United States, residing at Wilmerding, in the county of Allegheny, State of Pennsylvania, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to lifting-jacks, and is particularly adapted for all classes of work in which devices of this character are employed, as well as for use in connection with oil-well machinery for the purpose of manipulating the tools used in such work.

It has for its object to provide a novel means for communicating power from the operatinglever to the lifting-bar and for retaining said bar in its elevated position when the operating-lever is moved to obtain an additional elevation of the bar.

It has for a further object to provide animproved form of tripping device for the purpose of releasing the retaining mechanism when it 'is desired to lower the liftingebar.

Other objects and advantages of the invention will hereinafter appear in the following description, and the novel features thereof will be particularly pointed out in the appended claims.

In the accompanying drawings, Figure l is a vertical section through the invention.` Fig. 2 is a vertical section on the line 2 2 of Fig. l, looking in the direction of the arrow. Fig. 3 is a detail perspective of the tripping device. Fig. 4E is a similar view of the cam-lever. Fig. 5 is a detail of the clutch-block, and Fig. 6 is a plan of the lifting mechanism assembled.

Like letters of reference indicate like parts throughout the several figures of the drawings. v

The letter A designates a standard provided with a suitable base A and at its upper portion, with parallel segmental extensions A2. The upper portion of the standard is provided j with an enlarged recess A3 for the reception of the lifting, retaining, and tripping mechanism and with inwardly-turned walls ce at its upper portion to guide the lifting-bar B, which slides therein. The lower portion of said bar is provided with a foot I3', which is Serial No. 654,156. (No model.)

adapted to engage the article to be lifted, as is usual with this class of devices, and its upper end is provided with ahead B2for a similar purpose. The bar is smooth throughout its length and iits between the walls of the standard, so as to slide therein without friction.

For the purpose of lifting the bar an operating-lever O is provided, which is forked at its inner end, as at O', and pivoted to the segmental extensions A2 by any suitable meansfor instance, a bolt or pintle O2. Journaled upon the inner end. of this lever are oppositelydocated links D by means ofthe crossbar D2, carried by the forked ends of the lever O. The links are spaced apart and held in their relative positions by means of a sleeve D2. Embracing the 'lifting-bar is a strap E, formed in two parts E and secured together by means of a bolt e. The projecting ends of the portions E of the strap are provided with apertures to receive the pintles F of a cam-lever F, the outer end of said lever being pivotally connected withl the lower ends of the strap D by means of a j ournalingpin F2. The cam-lever F is provided with a face or seat portion f, which extends ai an angle to the pivots F', so that when the camlever is rotated it will bear against a clutch-block G, which is located between the lever and the lifting-bar to hold the lever in position. This block is provided with a roughened or serrated face G and at its rear with a recess G2, within which the end of the lever operates and against the wall of which it bears. By this structure it will be seen that when the end of the operating-lever is depressed motion willA be communicated through the links D to the cam-lever F, so that the same will be thrown into contact with the clutch-block and thus clutch the lifting-bar and lift the same in the upward movement of the .inner end of the operating-lever.

The means for retaining the lifting-bar in its elevated position consists of a strap E2, clutchblock G2, and cam-lever F3 similar to those just described, with the exception that the outer end of the cam-lever is not pivoted to any movable part, but rests upon a stop I-I. Extending downward from the upper portion a of the standard upon opposite sides of the roo lifting-bar are pins H, about which are located coil-springs H2, which bear upon the upper surface of the strap E2, and thus normally force the same downward so as to engage the outer end of the cam-lever with the stop H, and thus move the lever so as to bring the clutch-block into contact with the liftingbar. These springs and pins just described may be omitted and any other desirable form of spring used in their stead. It is obvious that the upward movement of the lifting-bar will carry this retaining device slightly upward with it and then pass freely through the same, while the downward `movement of the bar will bring the cam-lever into contact with the stop H and thus clutch and hold the bar against further downward movement.

When it is desired to release the retainin gdevice `from the bar in order to permit the same to be lowered, a tripping-lever is used, such as is shown in detail in Fig. 3, which consists of a horizontal portion I, j ournaled in the standard and provided at one end with an operating-handle I. Upon opposite sides of the lifting-bar the tripping device is provided with an arm I2, having upwardly-extending pins I3, between which and the lower side of the strap E2 are located springs I4, which are of greater tension or strength than the spring H2, heretofore described. The bar I is pr-ovided with a lug I5, which is adapted to seat itself in a recess I, formed in the standard, when the lug and recess come into alinement with each other. This lug is normally held intov contact with the side of the standard by means of a spring I7, located between the head I8 on the tripping device and one wall of the standard. From this description it will be seen that when the tripping device stands in the position shown in Fig. 1 the springs I4 are out of action, as their tension is less than the springs H2. If the handle of the tripping device be turned at this time, so as to bring the lug I5 into the recess I, the springs I4 would be compressed, and being of greater tension than the springs II2 when the weight of the lifting-bar is released will compress the springs H2, and thus release the clutch-block G, which retains the lifting-bar. This action of the parts will occur when the operating-lever is depressed so as to remove the weight from the retaining device and support it upon the clutch-block connected with the lifting-lever. When the weight is so supported, the tripping device will release the retaining-clutch, and the lifting-bar maybe lowered by gradual movement of the operatinglever, which at this time is clutched to the bar, or, if preferred, by throwing the outer end of the lever upward the bar will be dropped at once to its lowest position. The operation of the several parts has been fully described, and their relations to one-another in the operation of the lifting-jack as a whole will be clearly understood from the foregoing description.

It is obvious that changes may be made in the specific details of construction of the several parts of the invention without departing from the spirit of the same as defined bythe appended claims. For instance, the base or lower portion of the lifting-jack may be dispensed with below the line :n 5c in Fig. l of the drawings and the lifting, retaining, and tripping mechanisms mounted in any suitable manner to adapt them to different classes of work.

Having described our invention and set forth its merits, what we claim as new, and desire to secure by Letters Patent, is-

1. In a lifting-jack, the combination with a lifting-bar and its support, an operatinglever, a clutch-block adapted to engage said bar, a cam-lever operatin g against said clutchblock, and connections between said cam-lever and operating-lever, of a retaining-strap, a cam-lever pivotally mounted therein and bearing at its power end against a stationary member of the support, a clutch-block located between said cam-lever and lifting-bar, and a spring extending from said strap to said support to normally force the strap downward; substantially as specified.

2. In a lifting-jack, the combination with a lifting-bar and its support, of a retainingstrap, a cam-lever pivotally mounted in said strap and bearing at the power end against a stationary member of the support, a clutchblock located between said cam-lever and lifting-bar, and spring means to normally force said strap downward, substantially as specied.

3. In a lifting-jack, the combination with a lifting-bar and its support, of a retainingstrap, a cam-lever pivotally mounted in said strap and bearing at one side against a stationary member of the support, a clutch-block located between said cam-lever and liftingbar, and a spring located between the upper end of said strap and the support for the bar, substantially as specified.

4. In a lifting-jack, the combination with a lifting-bar and its support, of a retainingstrap, a cam-lever pivotally mounted in said strap and bearing at one end against a stationary member of the support, a clutch-block located between said cam-lever and liftingbar, a spring located beneath said strap, and means for increasing and releasing the tension of said spring, substantially as specified.

5. In a lifting-jack, the combination with a lifting-bar and its support, of a retainingstrap, a cam-lever pivotally mounted in said strap and bearing at one end against a stationary member of the support, a clutch-block located between said cam-lever and liftingbar, a spring located beneath said strap, and a pivoted arm upon which said spring is supported, substantially as specified.

6. In a lifting-jack, the combination with a lifting-bar and its support, of a retainingstrap, a cam-lever pivotally mounted in said strap and bearing at one end against a stationary member of the support, a clutch-block IIO located between said cam-lever and liftingbar, a spring located beneath said strap, a pivoted arm upon which said spring is supported, and means for retaining said arm in position to hold said spring under tension,

substantially as specified.

'7. In a lifting-jack, the combination with a lifting-bar and its support, of a retainingstrap, a cam-lever pivotally mounted in said strap and bearing at one end against a stationary member of the support, acluteh-block located between said cam-lever and liftingbar, a spring located between the upper end of said strap and the support for the bar, a spring beneath said strap, and means for placing and holding said spring under tension, substantially as specified.

8. A lifting-jack comprising a lifting-bar, an operating-lever, a cam-lever pivotally connected therewith and adapted to elevate said bar, a retaining device adapted to operate in the downward movement of said bar to retain the same in its elevated position, a tripping a cam-lever adapted to clutch said bar and pivotally connected to the operating-lever, a retaining-strap, a cam-lever pivoted 'therein to clutch said bar, a stationary support beneath the free end of said lever, and a spring bearing` upon the upper surface of said retaining-strap to normally force the same downward, substantially as specified.

l0.. A lifting-jack comprising a lifting-bar, a support therefor having oppositely-located extensions, an operating-bar pivoted between said extensions, a strap surrounding said bar, a cam-lever adapted to clutch lsaid bar and pivotally connected to the operating-lever, a retaining-strap, a cam-lever pivoted therein to clutch said bar, a stationary support beneath the free end of said lever, a pivotallymounted tripping device adapted to operate beneath said retaining device to elevate the same and release the clutch upon the bar, and springs interposed between said support and retaining device and between said retaining and tripping devices, substantially as specilied.

In testimony whereof We affix our signatures in presence of two witnesses.

JACOB A. STARRETT. EDVIN F. VELSH.

Vitnesse-s:

J os. WINGERsoN, GEO. N. BAUERsMrrH.

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