US905528A - Lifting-jack. - Google Patents

Description

J. S. HEARN.

LIFTING JACK,

APPLICATION FILED um. 12, 1908.

905,528. Patented Dec. 1,1908.

' A TTOHNEYS l 1: nomus PETERS c0, wAsnmcnm, n. z.

- able metal, having a base 10 on which tional view, substantially on the line 2-:2 in

JOHN SWLLINGER HEARN, OF JETT, KENTUCKY:

LIFTING-J'ACK.

Specification of Letters Patent.

Patented Dec. 1, 1908.

Application filed March 12, 1908. Serial No. 420,712.

12 all whom it may concern:

Be it known that I, JOHN S. l-Inann, a citizen of the United States, anda resident of Jett, in the county of Franklin and State of Kentucky, have invented a new and Improved Lifting-Jack, of which the following is a full, clear, and exact description.

This invention relates to a class of lifting jacks of the lever and lifting bar type, and has for its object to provide novel details of construction for adevice of the character :ini dicated, which are simple, durable, compact in arrangement; and adapt the device for manual. operation in different positions, enable the raising and lowering of a heavy load and afford a very powerful jack at a moderate cost.

The invention consists in the novel construction and combination of parts, as is hereinafter described and defined in the appended claims.

Reference is to be had to the accompanying drawings forming a part of this specifi cation, in which similar characters of refer-- ence indicate corresponding parts in all the views.

Figure 1 is a sectional side elevation of the jack, taken substantially on the line 1-l in Fig. 2; Fig. 2 is a vertical transverse sec- Fig. 1; Fig. 3 is a horizontal transverse secti onal view, substantially on the line 3-3 in Fig. 1; and Fig. at is a fragmentary side view of one side wall of the jack body, showing novel details of construction seen in direction of the arrow in Fig. 2.

The main frame for the incasement and upport of working details of the jack, comprises a box-like structure formed of suit-- erected a hollow column from which oppositely and laterally project similar hollow box forn'iations 10 that, together, afford an elongated chamber A. Upon the upper wall of the box formations 10 and integral therewith, an upward extensionlO of the column 10 is formed, that hollow, the cavity A. therein forming an upward continuation of. the chamber A, as is clearly shown in Fig. 1. One side wall of the chamber A is apertured to permit the introduction and proper location of working details within the casing of the jack, and this opening is normally closed by a cover plate 10 as shown in Figs. 52. and 3. I

In the column 10. a longitudinal channel each grooved side of said bar.

,tion and of a. suitable length, is loosely fitted in the alined channels a, a, and terminates at its upper end in a head block 11. shallow depression is formed in each of two opposite sides of the lifting bar, leaving. two

similar low flanges c, 0, remain standing on The opposite grooves, between the pairs of flanges 0 that are parallel with each other on their level bottoms, have similar ratchet toothed racks formed in said bottoms, these teeth 0 all hooking downward, as indicated in Fig. 1.

On the level bottom wall of the chamber A, two short racks d, d, are located, these toothed racks being formed or secured upon a base plate d that serves to space them apart and hold them stationary at opposite sides of the lifting bar 11. Two similar sectors 12 mesh their teeth 6 with the teeth of the racks d and. upon these sectors are upwardly extended arms 12 having an equal length. The sectors 12 are spaced apart and held upright, but free to rock, by a reciprocating frame consisting of two similar side plates 13, which are spaced apart parallel with each other by two pivots f, that carry the sectors 12. the latter working loosely on said pivots which are at their ends secured in the side plates 13; and to reduce friction between the arms 12 of the sectors and the inner surfaces of the side plates 13, washers f that are mounted upon the pivots f, may intervene between said parts, as indicated by dotted lines in Fig. l. A shifting frame is employed, consisting of two similar fiat bars 141 that are lapped at their ends upon the upper portions of the sectorarms 1? and pivoted thereto, as shown at g in Fig. 1.

An angle lever 15 is pivoted in the chamber A of the casing at. one open end thereof; the transverse pivot bolt 11., whereon the lever rocks, being secured at its ends in the side alls of the casing that define the width of the chamber A, and from the angle lever a lever proper 1,5, is outwardly extended, of a suitable length. Upon the short upwardly pro jected arm 15, that is a. member of the angle lever 15 one end of a short link bar 16 is pivoted as at g, the opposite end of the latter being pivoted upon the same pivot bolt 9 which loosely secures the adjacent ends of the frame bars 14L upon a correponding arm 12 of one of the sectors 12.

Between the side plates 13 of the reciproeating frame and near their upper edges, the lower ends of two similar pusher bars 17 are pivoted, as shown in Figs. 1 and 3, these bars of suitable length having each alaterally-bent toe or dog 2' that is adapted for entering spaces between the ratchet teeth 0 011 the racks at opposite sides of the lifting bar 11.

The disposal of the rack teeth 0, composing the pair of racks on the lifting bar, is such that they are positioned oppositely in pairs, and as the pusher bars 17 and the dogs z thereon have equal length, it will be seen that if the lever body 15 is disposed horizontally, the pusher bars will be positioned at an equal distance from the toothed racks on the sides of the lifting bar, and the dogs 2' on said pusher bars will occupy directly opposite depressions between oppositely paired teeth 0.

As shown in Fig. 1, each pusher bar 17 is engaged near the upper end thereof by the upper end of a depending plate spring 18 that is secured thereto, the lower ends of said springs having slidable contact with a side wall of the cavity A in the upper portion of the casing. On one side wallcof the cavity A and near the upper wall of the chamber A, is pivotally supported a rock arm 19. The rock arm is constructed preferably as shown in Figs. 1 and 2 and consists of a metal plate offset transversely, as at is, near its vertical center.

The pivot m for the rock arm is secured by one end of the pivot upon the central upper portion of said rock arm, and thence projects laterally therefrom, passing out through a perforation in the casing side wall and projects eXteriorly thereof sufficiently for the reception of a cam head m that is secured thereon. Upon the pivot bolt m, is mounted a coiled spring m that presses against the rock arm and inner surface of the casing side wall. Y

The cam head m is formed with two projecting members and a sloped surface between said projections, the latter being adapted to pass into corresponding openings m shown in Fig. 4, when the cam head and attached rock arm are rocked on the pivot mand dispose the upper portion of the rock arm in loose contact with the nearest side of the lifting bar 11.

It will also be seen that upon partially r0 tating the cam head m, the body or slope thereon will ride upon the side wall of the casing and draw upon the pivot bolt m so as to correspondingly pull the rock arm toward the side wall of the casing against stress of the spring m In further description of the rock arm 19,

it should be explained that its lower portion is formed with two limbs 19 of an equal width, their inner side edges being spaced apart and rendered parallel with each other, as shown at n. are separated sufficiently to adapt their in ner edges 11 to receive the impingement of a transt'erse presser pin a on the shifting frame alternately when the lever 15 is rocked and the shifting frame is reeiprocated its full distance of travel.

At each side of the pivot bolt m, the upper edge of the rock arm 19 is cut on an inelinc n outward and downward an equal degree, as shown by full and dotted lines in Fig. 1, and upon each pusher bar, at an equal distance from the ends of the dogs thereon, an abutment pin 0 is secured, and projects outwardly in the path of the sloped edges on the upper part of the rock arm when the latter is spring pressed into an engagement with the lifting bar 11. Directly above the pivot: bolt m and cam head m thereon, a flat carrier plate 79 is supported within the cavity A upon the side wall of said cavity by a short shaft 79, that is adapted for longitudinal adjustment in a perforation of said side wall, as is shown in Fig. 2. Upon the shaft p, a coiled spring 27 is mounted, having contact at its ends respectively upon the carrier plate p and side wall of the cavity A and on the outer end of said shaft a cam block 1 is pivoted, having a short arm 1 thereon which projects upwardly. The cam swell being disposed at one side of the arm 7", is removed from contact with the easement wall when said arm is rocked downward from the position shown in Fig. 2, into a horizontal one.

Upon the inner side of the carrier plate 7), two tripping pins 8 are projected therefrom, which are so spaced apart that when the cam block 1* is rocked so as to remove the cam swell thereon from contact with the side of the easement and thus permit the pressure of the spring 79 to project the carrier plate toward the lifting bar 11, the pair of tripping pins will pass into the spaces between the flanges 0 on the lifting bar 11 and the adj acent sides of the pusher bars 17 Furthermore, when the arm 1" is turned upwardly, as shown in Fig. 2, the plate 79 and pins 8 thereon will be retracted from the pusher bars 17 and be held in this condition by contact. of the swell on the cam block 1" with the outer surface of the easement side Wall, so that the tripping pins will have clearance from the lifting bar and the pusher bars 17'.

In operating'the jack for lifting a load that is placed upon the head block 11 of the lifting bar 11, the rock arm 19 is retracted from contact with the abutment pins 0 by adjustment of the cam head m, as is shown in Fig. 2. Upon rocking the lever 15 downward from a horizontal position, as shown The depending limbs 19,

cause a. corresponding inclination of the arms.

12 of the sectors, and a longitudinal traverse of the reciprocating frame that is pivoted on' said arms.

It will be noted that the endwise movement of the bars 11, caused by an inclination of the sector arms 12, will correspondingly lower the pusher bar 17 at the left of Fig. 1 and raise the other pusher bar an equal degree. This change in position of the pusher bars 17 will. adapt their upper ends or dogs 2' to respectively drop between the teeth 0 on the racks, being pressed by the springs 18 into such an engagement; and the dogc' at the left hand rack, is lowered son1ewhat, it will engage between the rack teeth of on said rack, one or two teeth (preferably one tooth) lower than the. righthand dog has engagement.- between, this relative engagement of the dogs being clearly shown in Fi 1. The lever 15 that was depressed, whi e the dogs were given the positions just described, is

now raised its limit of upward rocking movement, which 'will push the arms 12 of the sectors 12 in an opposite direction, which will lower the right hand dog 2' and correspondingly raise the left hand one.

Obviously, the limited elevation of the left hand dog 71 will correspondingly raise the lifting bar 11 and the load thereon, and at the same time the right hand dog will drop between the teeth, one or two numbersbelow those engaged by the left hand dog.

It will be understood from the foregoing description that by a rocking movement of the lever 15, up and down, the change in the a relative position of the pusher bars 17 and dogs 2' thereon will be alternately effected, and the loaded lifting bar becorrespondingly elevated; and it will be noted that at any point of elevation given to the lifting bar, the twin pusher bars and their dogs 2' will co-act for supporting the elevated bar and load.

At any time it is necessary to lower the lifting bar 11 with a load on it, this may be readily accomplished by first changing the adjustment of the rock arm 19, so as to dispose its upper portion close to the lifting bar. To this end, the cam block m that is normally in the relative position shown in Fig. l, should receive a partial rotation toward and over the openings m so as to permit the block and shaft m to be pressed inward by the spring m and thus force the rock arm 19 toward the lifting bar 11. The inward adjustment of the rock arm 1.9, locates the sloped upper edges n thereon close to the abutment pins 0, 0, so that a rocking movement of the arm 19 will cause an alter nate elevation of and impingement of said edges upon the lower sides of said abutment pins.

Assuming that the ack and lifting bar 11 are disposed vertically and that the lifting bar and a load thereon are to be lowered more or less, and that the lever 15 has been rocked somewhat below a horizontal posi tion, as shown in Fig. 1, it will be seen that the impingement of the'presser pin it upon the edge a on the left hand limb of the rock arm, will have disposed the sloped top edge 11. at the right of the pivot m below and near the abutmentpin 0 on the right hand pusher bar 17. The dog 2' on the pusher bar mentioned, is engaged between two of the rack teeth 0 and co-acts with the dog on the other pusher bar for support of the lift ing bar 11.. proper distance, which will cause the presser pin a to move toward the opposite edge a on the rock arm 19 and contact therewith. A continuation of the upward rocking movement given to the lever 15, will. cause the right hand sloped edge n of the rock'arm to press the adjacent abutment pin 0 upward and outward, thus forcing the right hand dog 71 out of engagement with the right hand rack teeth 0.

It will be noted that the dog at the left side in Fig. 1 is still interlocked between two teeth 0 on the left hand rack, but as the abutment pin 0 on the left hand pusher bar 17 had been positioned at the side edge of the rock arm slightly below the left hand top edge 11?, it will be seen that the elevation of the lever 15 will press the sloping top edge of the rock arm below the abutment pin it is opposite to, and rock the right hand pin 0 upward sons to permit the force of the adjacent spring 18 to press the right hand dog i toward the rack it is opposite and engage between two teeth 0. The next downward stroke of the lever 15 will rela tively change the rocked adjustment of the rock arm 19, so as to dispose it as shown in Fig. 1, release the left hand dog and permit the lifting bar to descend the distance between the two teeth 0 and a continuation of the operation will lower the lifting bar and its load any distance desired.

In case it is desired to release the lifting bar 11 and permit it to freely slide downward for closing the jack when not in use, the device controlled by the cam head r, shown in Figs. 2 and 4, is employed; to this end, the cam head 7 is rocked so as to project the-arm p thereon outward, which will permit the spring 79 to force the carrier plate 7) and pins 8 thereon toward the lifting bar 11, the pins passing between said lifting bar and the pusher bars 17.

The pins 8 are sloped on the sides nearest to. the pusher bars 17 and by their wedging action, press the latter outward. thus releas- The lever 15 is now elevated a ing the dogs 2' from the rack teeth 0, which will permit the lifting bar to descend, which movement may be arrested by turning the arm of the cam block 7" upward and withdrawing the pins by a retraction of the car rier plate p.

The jack may be used iflying on its side, or if inclined at any angle, and being light, can be readily handled to place it in position for service.

As the peculiar construction and arrangement of parts affords a compound lever having toggle action, it will be evident that the easy movement of the operating lever, will produce sufficient power to lift or move very heavy weight engaged by the lifting bar of the ack.

Having thus described my invention, 1 claim as new and desire to secure by Letters latent:

l. A jack, embodying a body having a chamber therein, a lifting bar slidable in the body, two racks oppositely disposed on the lifting bar, a reciprocal frame, two pusher bars pivoted at their lower ends on the reciprocal frame, a lever pivoted near one end in the chamber, dogs on the upper ends of the pusher bars adapted for engagement with the racks, and means connecting the lever with the reciprocal frame for its sliding movement and the actuation of the pusher bars.

2. A lifting jack, embodying a hollow body, a lifting bar slidable vertically in the body, a toothed rack on each of two opposite sides of said lifting bar, two toothed racks horizontal in the body, sectors having arms and teeth that engage the racks, a reciprocating frame having two side plates that embrace the arms of the sectors and are pivoted thereon, an angle lever having an extension for rocking movement and pivoted in the body at an open end thereof, two pusher bars pivoted at the lower ends thereof between the side plates and projecting upward at the respective racks, each pusher bar having a dog on the upper end that engages with teeth of an adjacent rack, a spring on each pusher bar that presses a respective dog toward an opposed rack, and means connecting the upper ends of the arms on the sectors with an end of the angle lever.

3. A jack, embodying a body having a chamber therein, a lifting bar longitudinally slidable in the body and projecting therefrom at one end, two ratchet toothed racks embedded respectively in the opposite sides of the lifting bar, a pair of toothed racks horizontally. securedon the bottom of the chamber, one on each side of the lifting bar. a toothed sector meshed with each horizontal rack, a reciprocal frame having two side plates between which the lifting bar works.

arms 011 the sectors being disposed between the side plates and pivoted thereon, two pusher bars pivoted by their lower ends, one each side of the lifting bar, each pusher bar extending upward and having a dog on the upper end that engages with the teeth on a respective ratchet toothed rack, a shifting frame comprising two bars that embrace the upper ends of the sector arms, a link ex tended from one end of the shifting frame, an angle lever pivoted at its angle upon the body at one end of the chamber therein, an arm on the angle lever being pivoted at its end on the remaining end of the link, and an elongated lever extending from the angle lever.

l. A jack, embodying a body having a chamber therein, a lifting bar slidable vertically in the chamber and in a channel that extends above and below said chamber, a reciprocal frame, toothed racks on the bottom of the chamber, toothed sectors having arms that are pivoted between the sides of the reciprocal frame, a shifting frame having side members pivoted at their ends upon the upper ends of the sector arms, pusher bars pivoted at the lower ends thereof upon the reciprocal frame and extended upward, a dog on the upper end of each pusher bar, a spring pressing each dog, a toothed rack on each of two opposite sides of the lifting bar with which the dogs respectively mesh, an abutment pin on each pusher bar, a presser pin carried by the shlfting frame, a rock arm having spaced limbs that alternately engage with the presser pin, and spring pressed means for controlling the ad: justment of the rock arm toward the abutment pins.

5. A jack, embodying a body having a chamber therein, and also having a vertical channel that crosses the chamber, a lifting bar slidable in the channel and chamber, a toothed rack on each of two opposite sides of the lifting bar, a horizontally reciprocating frame, pivoted and spring pressed dogs carried by the frame and engaging the racks to hold the lifting bar elevated, means for reciprocating the frame to alternately lower and raise the dogs so as to elevate the lifting bar by a step by step movement, and spring pressed members adapted to project into the spaces between the dogs and lifting bar for simultaneously pressing the dogs away from the racks and permitting the lifting bar to slide downward.

6. A jack, comprising a support, a lifting bar mounted to slide in the support and provided with teeth on opposite sides, a horizontally reciprocating member, pivoted and spring pressed dogs carried by the member and engaging the teeth of the lifting bar, means for reciprocating said. member, arock arm for engaging the dogs to disengage them from the lifting bar, and means for operating the rock arm by the reciprocation of the said member.

7. A jack, comprising a support, a lifting bar mounted to slide in the support and having teeth 011 opposite sides, a reciprocating frame, pivoted and spring pressed dogs carried by the frame and engaging the teeth of the lifting bar, a shifting frame, means for reciprocating the frame carrying the dogs from the shifting frame, and means for operating the shifting frame.

8. A jack, comprising a support, a lifting bar mounted to slide in the support and having teeth on opposite sides, a reciprocating frame, pivoted and spring pressed dogs carried by the frame and engaging the teeth of the lifting bar, toothed sectors pivotally mounted in the frame, stationary racks with which the sectors engage, and means for rocking the sectors.

9. A jack, comprising a support, a lifting bar mounted to slide in the support and having teeth on opposite sides, a reciprocating frame, pivoted and spring pressed dogs carried by the frame and engaging the teeth of the lifting bar, a shifting frame, means for reciprocating the frame carrying the dogs from the shifting frame, means for operating the shifting frame, and means open ated by the shifting frame for alternately disengaging the dogs from the teeth of the lifting bar to permit the lifting bar With its load to be lowered.

10. In a ack, a sliding lifting bar having teeth on opposite sides, pivoted and spring pressed dogs engaging the teeth of the lifting bar, means for operating the dogs to cause them to elevate the lifting bar, a mannally controlled pivoted member having means for engaging the dogs to alternately disengage them from the teeth of the lifting bar, and means for operating the said member from the dog operating means.

11. In a jack, a sliding lifting bar having teeth on opposite sides, a reciprocating member, pivoted and spring pressed dogs carried by the reciprocating member and engaging the teeth of the lifting bar, said dogs being provided With projections, means for reciprocating said member, a manually controlled pivoted member having inclined surfaces for engaging the projections of the dogs, and means for rocking the said member from the reciprocating means to bring its inclined surfaces alternately in engagement With the projections of the dogs.

12. In a jack, a sliding lifting bar having teeth on opposite sides, a reciprocating frame, pivoted and spring pressed dogs carried by the frame and engaging the teeth of the lifting bar, the dogs having lateral projections, a shifting frame having a projection, means for reciprocating the dog carrying frame from the shifting frame, means for operating the shifting frame, and a manually controlled pivoted and spring pressed member having a forked lower end straddling the projection of the shifting frame and provided with inclined surfaces for engaging the projections of the dogs.

13. In a jack, a sliding lifting bar having teeth on opposite sides, pivoted and spring pressed dogs for engaging the teeth of the lifting bar, said dogs having lateral projections, means for operating the dogs to raise the lifting bar, a pivoted and spring pressed arm having opposing inclined surfaces for engaging the projections of the dogs, means on the pivot of said arm for looking it against the action of its spring to hold it out of the path of the projections of the dogs, and means for rocking the arm from the dog operating means.

14. In a jack, a sliding lifting bar having teeth 011 opposite sides, pivoted and spring pressed dogs engaging the teeth of the lifting bar, means for operating the dogs to raise the lifting bar, a sliding and spring pressed member having tripping pins projecting therefrom, said pins being adapted to project into the spaces between the dogs and the lifting bar, and means for operating said member.

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

JOHN .SWLLINGER HEARN.

Witnesses:

L. J. WALLACE, I. H. HEARN.

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