US874061A

US874061A - Lifting-jack.

Info

Publication number: US874061A
Application number: US36428607A
Authority: US
Inventors: George F Freed
Original assignee: DUFF Manufacturing CO
Current assignee: DUFF Manufacturing CO
Priority date: 1907-03-25
Filing date: 1907-03-25
Publication date: 1907-12-17
Anticipated expiration: 1924-12-17

Description

WITNESSES PATENTED DEC. 17, 1907.

G. P. PREED.

LIPT'ING JACK.

APPLIGATION FILED MAR, 25, 1907.

INVENTOR k QMMW W, Q s (Um 7 .To all whom it may camera:

UNITED STATES GEORGE F. FREED, or ALLEGHENY, PENNSYLVANIA, ASSIGNOR'TO THE FAOTURING COMPANY, or (ALLEGHENY, PENNSYLVANIA, A

PENNSYLVANIA.

Be it known-that IfGEORGE F. FREED, of 1 Allegheny, Allegheny county, Pennsylvania, have invented a new and useful Lift ing-Jack, of which the following is a full,

v clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a side elevation with the face plateremoved showing my improved form of jack; Fig. 2 is a detail viewof the tripping plate; and Figs; 3 and 4 are detail views of parts hereinafter referred to.

My invention relates to the class of lifting jacks which give a step by step movement in either direction; and particularly to the well known Barrett type of jack.

The object of the invention is to avoid the side thumb nut which has heretofore been employed, and provide an improved reversing device having operating means which extend and may be actuatedfrom the front of the jack.

' It is also designed to rovide a reversing lever which will .be with1n the side limits of the frame.

In the drawings in which I show my invention as applied to the well known Barrett type of jack, 2 re resents the frame and 3 the lifting bar whic moves longitudinally therein. The frame is preferably provided with a flange 4 and socket 5 receiving the inner end of the operating lever 6. This lever is pivoted on a pin 7 extendin through the sides of the socket, and to sair lever at a point in front of the fulcrum is ivoted a awl 8 engaging the ratchet teet on the ar 3. The pawl or detent 9 is pivotally mounted on a pin lflpassing through the sides of the socket, this detent being outside of the pawl 8 and engaging the bar teeth about it. The pawls 8 and 9 are normally held in engagement with the ratchet teeth the lower ends thereof inwardly or to the left, as shown in Fig.1 but as the outward movements of the upper ends are prevented Specification of Letters Patent.

A plication filed mmh 25.1907. Serial No. 864.285.

placed coil springs, one end ofmma;

Patented Dec. 1"7',.1 oo7. 'f

the levers are forced inwardly or to the left, thereby moving the awls into engagement with the ratchet-teeth on the bar 2.

In the lifting-jack constructed as herein; before described, the liftingbar is raised during the downstrokev of the operatinglever 6, and held in such raised position by the pawl ordetent 9 durin the upstroke of said lever, the pawl 8 and detent 9 being bar by the spring-levers 11 and 12.

In order to lower the bar or permit the" movement under the action of the load,.jthe above-describedoperation of the pawls must be held away from the bar 2 during the upstroke of the operating-lever and caused to engage one of the teeth of the bar at the end of such stroke, While the pawl 8 must he held stroke of the lever, and at. theendfof L downstroke must engage one of the teeth of, the bar 2 and retain such engagement until .the end of the upstroke, when it is forced out of en a ement with the ratchet-teeth again; It will e'understood that the outer end io f the lever 6 is referred to in the above state; ments as to the directions of the strokfe i: This reversal of the normal operation of the pawl and detent is effected by the tripping face with a pro ection 17'having a suitably' shaped cam surface for engagement with the lower end ofthe lever 11, and with a bearing-point or stop 18 for engagement with the auxiliary or releasing lever 19, piv- ,oted on the lower end of the lever 12, as eshown in Fig. 1. 1

The tripping plate 16 is pivoted to the abutment of the frame at 16, and its lower forward end is formed with a nose 20 which is supported by a star wheel 21. This wheel has a series of teeth or projections, the apex of each of which is preferably formed with a slight indentation 22 to retain the-nose of the tripping plate, and between these two adjacent teeth is a depression 23 in which the nose of the tripping plate is also adapted to rest. The star wheel 21 is loosely mounted ona stud 24, and has secured thereto a ratchet P1ate Big 2), provided on its inner and a projection 15 on the fever 11 hearing against the lever 12, the lower portions of held against the ratchet-teeth of the liftingbe reversed, i. 0., the pawl or detent 9 must away from the ratchet-teeth during thedown 9h.

Wheel 25, the teeth of which are arranged to be engaged by pawl 26 which is pivoted to alever arm 27'loosely fulcrunied on the stud 24. A spring 28 is coiled to the stud 24 with one of its ends connected to the lever arm and its other end to a fixed pin or stud 29. Attached to the lever arm is a cord, chain, or link 30 which extends thro h a guiding eye or lug 31 of the frame, in a i'rection parallel to the operating lever.

When lifting the bar step by step, the parts are in the position shown in Fig. 1, with the nose of the tripping plate resting in the depression between two of the teeth of the star wheel. When it is desired to reverse the operation for the purpose of lowering the bar ste by step, the chain, link, or cord, 31 is pu led, thereby causing the operation of the pawl and ratchet to move the star'wheel a suificient distance'to cause the nose of the tripping plate toride on to the top of the next adjacent tooth; This forces the tripping late upwardly and toward the right, there y bringing the projection 17, and the bearing-point on the stop 18 into operative relation with the lever 11 and the auxiliary or releasing lever 19, thereby efiecting a reversal of the pawls. Another pull on the chain or cord 31 will permit the tripping plate to drop into one of the depressions of the star wheel which returns the parts to their former position for lifting the bar.

The lifting and lowering movements of the bar will be obvious, being the same as in the ordinary Barrett jack. The feature of my invention consists in the novel form and arrangement of the tripping plate in connection'with the reversing mechanism therefor,

which may be operated from the front of the jack.

" The advantages of my invention result from the provision of reversing mechanism which may be actuated from the front, there'- by obviating the necessity for reaching through a wheel when the jack is used in connection with automobiles or other vehicles; The construction also en its the jack ens ing to be placed along the side wall or other obstruction which would prevent access to the ordinary reversing button at the side of the Barrett jack.

Various changes may be made in the form and arrangement of the tripping plate, and of the reversing mechanism therefor, without departing from my invention, since What I claim is:

1. In a step by step raising and lowering jack, a tripping plate, a rotatable member adapted to hold said platein either one of two positions, and means for actuating said member to rotate it in one direction only; substantially as described.

2. In a'step by step raising and lowering jack, a tripping plate, atoothed reversing wheel therefor, and means for rotating the Wheel; substantially as described.

3. In a step by step raising and lowering jack," a tripping plate, a toothed reversing wheel therefor, lever and pawl and ratchet mechanism for operating s'aid wheel, and meansfor operating the lever; substantially as describec. i

4-. In a jack of the Barrett type having step by step raising and lowering mechanism, a pivoted trilpping plate, a star wheel arranged to ho d the tripping plate in either one of two positions, and means for actu-- ating said wheel from the front of the jack; 7

substantiallyas described.

5. In a step bystep raising and lowering jack, a trip ing plate, a rotatable member adapted to old said plate in either one of two positions, said member having a plurality of plate actuating I projections, and means for actuating said member to rotate it in one direction only; substantially as described.

In testimony whereof, I have hereunto set my hand.

GEORGE F. FREED.

, Witnesses: I

J. 0. Jamison, A. E. Ass.