US3159382A - Automobile jack - Google Patents

Description

1964 A. .1. BELANGER 3,159,382

AUTOMOBILE JACK Filed May 1963 3 Sheets-Sheet l I INVENTOR. APP/VI? J. EfZA/I/GEE 'AfTd/P/Jfff 1964 A. J. BELANGER 3,

AUTOMOBILE JACK Filed May 31, 1963 3 Sheets-Sheet 2 I NVEN TOR. ARTHUR J. BEAM/65E W 1964 A. J. BELANGER 3,

AUTOMOBILE JACK Filed May 31, 1963 5 Sheets-Sheet 3 fie. M,

INVENTOR AFTHM? 1/. Bi'M/VGEE United States Patent 3,159,382 AUTOMQBEE .iAQK Arthur .l. Belanger, 321 .6 fianford St, fvluskegon, Mich. Filed May 31, 1963, Ser. No. 286,106 9 Claims. {65. Ha -16195) This invention relates to a hoist mechanism, especially a vehicle hoist or jack, and more particularly to a chainlift hoist.

This application is a continuation-in-part application of my copending application entided Automobile lack, filed June 26, 1962, Serial No. 205,278 now abandoned.

Various types of chain hoists have been devised heretofore. Since the chain is a flexible and highly adaptable tension element, it is advantageous to use. As far as is known, however, none has ever gained wide acceptance for use as a vehicle jack. Heretofore, it has been difiicult, if not impossible to achieve a simple, manual drive means for the chain to enable a large mechanical advantage to be obtained without a complex winching action. Further, as far as is known, no really satisfactory method of controllably reversing movement of the chain has been possible on a small scale for lowering the vehicle on the jack or hoist.

It is therefore an object of this invention to provide a compact, chain hoist mechanism enabling simple, manual operation while also achieving a large mechanical advantage.

It is another object of this invention to provide a chain hoist enabling smooth operation as a vehicle jack, thereby providing the jack with the flexible characteristic of a chain without the operating difficulties and reverse move" ment difficulties experienced heretofore.

It is another object of this invention to provide a rollerchain hoist having an easily controlled reverse action in eccentric element. Further, the eccentric is controlled in the amount of binding force which it applies to the roller chain due to a control element operable between the eccentric and its mounting bracket.

It is still another object of this invention to provide a chain hoist having an easily cor roiled reverse action in a link by link manner by the use of magnetic actuating means mounted on the handle of the jack.

These and many other objects of this invention will be apparent upon studying the following specification in conjunction with the drawings in which:

FIG. 1 is a side elevational view of one form of the novel jack or hoist during hoisting operation, and showing the eccentric and handle being shifted in an upward movement just before moving downwardly to lift the hoist mechanism;

FIG. 2 is a fragmentary, side elevational view of the apparatus in FIG. 1 after the eccentric and handle is in the upper-most position and the handle is being lowered to raise the chain hoist mechanism;

FIG. 3 is a front elevational view of the apparatus taken in the direction of Ill as indicated by the arrow in FIG. 2;

FIG. 4 is a fragmentary, side elevational view of the hoist apparatus during the lowering operation, showing the link by link release of the chain;

FIG. 5 is a top sectional view taken on plane VV of the apparatus as illustrated in FIG. 4;

FIG. 6 is a fragmentary, elevational view of the end of the hoisting chain showing a slightly modified operation thereof;

FIG. 7 is a fragmentary, perspective view of the end of the chain hoist showing a still different modified operation;

FIG. 8 is a fragmentary, perspective view of a modified form of the jack;

cation of the handle and ececntric.

Patented ec. l, 1964 "ice FIG. 9 is an exploded perspective view of the modified jack;

FIG. 10 is a fragmentary side elevational view of the modified jack;

FIG. 11 is a fragmentary side elevational view of the modified apparatus with the chain being disengaged from chain catch hook; and

PEG. 12 is an enlarged fragmentary view of the chain link cam and a chain link.

Basically, the inventive hoist mechanism comprises a support, a sprocket means rotatably mounted on the support, a hoisting roller chain around the sprocket, and a handle-operated eccentric mounted adjacent the sprocket and chain, and adapted to be shifted into engagement with the chain between adjacent rollers to shift the chain around the sprocket a limited amount. The eccentric is pivotally mounted on a bracket, which is in turn pivotally mounted to the upper end of the vertical support or stand. The eccentric includes a lobe movable into engagement between adjacent rollers on the sprocket. Further shifting of the handle shifts the chain and sprocket a predetermined amount. Catch means on the stand holds the chain in its shifted position with each recipro- The engagement force of the eccentric on the chain roller is limited by a roller element between the eccentric and its mounting bracket, causing a binding action after. the engagement between the eccentric and roller chain occurs. Before this binding occurs, the handle and eccentric move with respect to the bracket. After the binding the handle and bracket move as a unit.

The hoist apparatus also includes a unique lowering or reverse action release mechanism including a lifting pin means. This lifting pin is actuated by the actuation means on the handle during upward movement of the handle. The pin shifts the individual rollers around the chain catching hook to enable a link by link lowering. The actuating means on the handle is preferably a magnet which shifts the releasing pin means a predetermined amount to release one link of the chain, and then break loose from the releasing pin means to allow the next roller of the chain to catch on the hook.

Referring now to the drawings, in the form of the invention illustrated in FIG. 1, the novel hoist apparatus ill includes a support means 12, a hoisting chain means '14, and an eccentric mechanism 16.

The support or stand 12 preferably includes a cylindrical sleeve 18 which interfits telescopically with a cylindrical element 29 projecting upwardly from base 22. The upper end of the cylindrical stand is machined away to provide a slot and a pair of spaced ears 26 and 28 illustrated in FIG. 3. Between these ears extends a central pin3ll upon which sprocket 32 is fixedly mounted. The teeth of this sprocket project between the adjacent rollers 49 of roller chain 14. The rollers are interconnected by side links in a conventional manner.

On the front end of the roller chain 14 is provided a hook 432 for hoisting purposes. This hook may interfit with an inverted U shaped bracket 46 welded or otherwise suitably affixed to the lifting support 48. The lifting support is integral with a cylindrical guide sleeve Sil which surrounds the stand 18 and moves vertically up and down on it. Upon the upper surface of this support 48, an automobile bumper 54 may be placed for hoisting purposes. To alleviate frictional contact be tween cylindrical sleeve 5 3 and stand 18, a pair of diagonally located rollers 56 and 58 are provided.

The opposite end of the chain may pass through a suitable opening 60 (FIG, 3) into the cylindrical stand 18 for proper storage of any chain slack as the chain is moved back and forth around the sprocket 32.

Movement of the chain and sprocket is effected with l in FIG. 1.

the eccentric mechanism 16. This eccentric includes a lobe 7i beneath the pivotal pin 72 where the eccentric is pivotally mounted on the vertically extending bracket 74. This bracket includes two downwardly extending legs 76 and 78 pivotally mounted on pin 3b,.and includes rollers 46, or out of engagementterewith to allow movement of the handle over the rollers as illustrated The pressure of the lobe '76 on the rollers of the chain is limited by the binding action which occurs between the roller element or ball as inserted between the portion of eccentric 16 opposite lobe 7t), and the top surface 8t) of bracket '74. Bracket 74 pivots independently of the sprocket 32. Roller member 96 is retm'ned in the housing by downwardly depending front and rear flanges 199 and 1&2 on bracket 74. tang 106 of theeccentric.

Thehoisting chain 14 is held in any position by hook H98 which is integral with stand 13, and projects slightly downwardly as illustratedin FlGS. 1 and 2. Even with the Weight of an automobile (see bumper 54) on support 43, the chain will not allow the sprocket 32 to rotate counterclockwiseuntil the chain rollers are released [from this catch hook 1'38. 7

During the hoisting operation of the apparatus, handle 84 is rotated downwardly. It first moves with respect to bracket '74 to cause an engagement between lobe 7d and a pair of adjacent rollers 40 as illustrated in FlG. 2. The binding force of this engagement is limited by the ball 96 which binds between the upper surface of the eccentric and the top surface 8t) of bracket 7 4 illustrated in FIG. 2 when the handle is rotated further. Additional downward rotation of the handle 84 in the direction of the arrow illustrated in FIG. 2 then causes the bracket 7 4 to also rotate about its pivotal shaft 30 to thereby rotate bracket '74. After it rotates a srnall arnount the eccentric abuts flange 162 and causes the entire bracket to pivot upwardly and counterclockwise as well as the handle and eccentric. Thereby, the handle can be pivoted and the bracket can be pivoted counterclockwise into its original position illustrated in FIG. 2 to enable another downward movement of the eccentric apparatus. The uppermost position of the handle and bracket can be determined by a stop 81 on the bracket (FIG. 1) which abuts the car 78 of the stand 18. The handle is repeatedly reciprocated until the object is hoisted the desired amount by travel of support 48 up stand 18.

Reverse movement of the apparatus to lower the hoist is accomplished as the result of two specific actions. First, the individual rollers 49 of the chain must be released one at a time from beneath the retaining catch means or book 1%. Also, movement of the chain in reverse direction must be manually controlled by eccentric 16 and handle $4 to prevent a jumping action under the weight of the vehicle. I

The first action, i.e. the release of the individual rollers rorn around hook 168, is achieved through a special lifting or hoisting pin 134 (FIG. 5) which is adapted to It rests in a recess adjacent extend between the rollers 49 to enable lifting of each roller one 'at a time around the book. This pin 114 includes a portion extending through opening 116 in cylinder 118 (portion 12b) to serve as a guide, a retracting means, and an extension limit means, A tension spring 122 is secured between the inner end of this portion 12b and a screw 124 extending across the cylinder 113 to retract the pin. A washer 132 retained on portion 12%? by a pin or cotter key 134 limits the extension of the pin. Pin 1114 also includes a loop-shaped projection 139 which enable activation of the pin hoist by actuation means 133 on handle 84;. The releasing pin 114 and its extension 132% are extendible to the position illustrated in FIG. 4 against the bias of spring 122 until washer 3132 abuts the inner surface of the cylinder 113.

The actuation means 133 is' preferably a magnet mounted to a handle by a suitable bracket 140 and bolts 142. During the normal hoisting operation, a keeper 15b is placed across the poles the magnet 138 as illustrated in PEG. 1. Thus, the magnet normally does not actuate the pin releasing means during the upward move ment of the handle 84. When it is desired to lower the hoisting mechanism, i.e., cause the chain and sprocket to move in a counterclockwise direction 'as illustrated in FIG. 4-, the keeper i5 9 isremovcd from magnet 3138. Then, as handle 84 is lowered, the magnet comes in contact with extension 13% of the pin release. As the handle is raised again (as illustrated in FIG. 4), the magnet pulls the pin release upwardly and outwardly until washer 132 contacts the inner wall of the cylinder 18. As the pin lidis raised upwardly and outwardly, it lifts a roller lit of the chain aroundhook ass to allow that roller to be released for counterclockwise movement of the chain. As soon as the magnet has reached the position illustrated in FIG. 4, and the washer 132 abuts the cylinder '18, rfurther movement of the handle causes release of the magnet from the extension 13% thereby causing the spring 122 to retract the releasing pinil l. This initial releasing action occurs. with the ball as at the front of bracket 743 as illustrated in PEG. 4. At the time the magnet releases portion 13%, however, the ball as rolls against ear or tang (see arrow FIG. 4) Ittld. Lobe 7th is engaged'between two adjacent rollers 4th to allow the operator to manually control the rate at which the chain and the sprocket move counterclockwise to lower the vehicle. 011 the next downward stroke of the handle, the operator prevents the binding action between the eccentric 16, ball '96 and upper surface 8%) of the bracket 7 to thus prevent the lobe 70 of the cam from engaging between the rollers. This done by keeping the handle in its most counterclockwise position with respect to the bracket '74 while rotating the handle and bracket clockwise. Gn the downward movement of the handle, therefore, no hoistlog occurs. Magnet 13% then comes in contact with extension 13% again to repeat the lowering step, a link at a time. 1

Gperation of the apparatus as explained with respect to the particular structure above is thus obvious from this prior description. Briefly, when an automobile illustrated by bumper 5 i is'to be hoisted, itis placed above support 48. Keeper 15b is placed on magnet E38. Handle as is reciprocated vertically, i.e. in alternate clockwise and counterclockwise directions to rotate sprocket 32 clockwise. During the hoisting operation, the handle is first deliberately rotated clockwi e with respect to the bracket 74 to engage the lobe 78 with the rollers 4t) and binds the ball 96 between the eccentric and the bracket. This engagement is released in the upward reverse direction. Alternatively, when lowering the hoist, i.e. causing the sprocket and chain to move counterclockwise, the lobe 7 7b is purposely prevented from engagingthe rollers 40 on the downward movement, i.e. the handle and eccentric i are retained in their counterclockwise position with respect to the bracket 745 011 the downward movement, and on the upward movement, lobe 7th is purposely engaged $3 with the rollers. Since the weight of the vehicle tending to move the chain in a counterclockwise direction will tend to force the handle upwardly and the operators hand will be pushing downwardly on the handle, the handle eccentric will be in the clockwise most position with respect to the bracket to control the downward movement of the chant.

Instead of the apparatus being used in the form illustrated in FIG. 1 with the support 48 directly onto the hook 42, the hook 42 may be used directly on a bumper 54 as illustrated in FIG. 6. Alternatively, the U-shaped inverted bar 46 may be provided with a roller 18% fitting between the side links of the chain 14 as illustrated in FIG. 7. In this form of the invention, not only will the bumper 54 rest on the support 48, but also the chain will pass around the roller 130 and hook 42 will engage the top of bumper 54 to hold it in a secure manner. Thus, raising of the chain illustrated in P16. 7 will cause movement of the chain along roller 18% to give a smooth controlled hoisting or lowering of the vehicle. Obviously, various other forms of securing the chain hoist to the particular article to be hoisted or lowered may be utilized.

Modified A ppamius Referring to FIGS. 8 through 12, a modified and preferred form of the apparatus using a mechanical cam to release the chain, instead of the magnetic releasing means, is illustrated. The novel modified jack 2% includes a suitable base, an upright support 2&9, a pivotal handle bracket 2%, and a camming handle 2% similar to those in the previously illustrated form.

The upright 262 includes a pair of oppositely positioned vertical slots 2&8, in which the chain sprocket Zltl fits to be rotatably mounted on transverse pin 212. The pin is rotatably supported on upright post 2% in a pair of opposite openings 214, 90 removed from slots 2498. The roller chain 22% includes suitable bumper hook means (not shown in FIG. 8 but similar to the previous type shown) attached to end 22th of the chain. The other end of the chain is slack, and may be positioned within the hollowed post 2&2 through a suitable orifice 224. The roller chain passes over the top of sprocket 218 as previously.

Bracket 2% has a pair of spaced openings 23th and 23b in the lower ends of its legs to be pivotally mounted upon pin 2&2. extending through the top of the post. The bracket also includes a pair of openings 234 near its upper end to receive cylindrical pin 2%, also inserted through opening 238 in the eccentric head 245 on the end of handle 2%. The opening 233 is mounted oif the center line of eccentric 249, to cause the lower eccentric surface 24% to move into engagement between a pair of links of the roller, chain, or out of engagement therewith when the handle is pivoted upon pin 236.

The head normally fits between the legs of the generally inverted U-shaped support bracket 2&4. Thus, the handle may be pivoted with respect to the bracket, and the bracket may be pivoted with respect to the post, as necessary. Pivoting of the handle moves the eccentric into and out of engagement with the roller chain, while pivoting of the bracket enables a bite to be obtained on the chain when the handle is depressed for engagement of the eccentric with the roller chain. The top of the eccentric 246 includes a recess 25% within which a ball 252 fits in order to lock the handle with respect to the bracket 2% as described with respect to the previous modification.

Protruding from the surface of cylindrical pin 212 is an engagement tooth 26% which fits within slot 262 out into the periphery of the post opening 214. The slot is provided with an arcuate width somewhat greater. than the width of element 269, to allow a slight amount of play between the cylindrical pin and the slot. Also, the opening 23% on one side of bracket 204 includes a wide arcuate slot 2232 cut into its periphery to receive a control stop 270. The control stop lever 27% has a cylindrical shank 272 which fits within a special opening 274 in connecting pin 212 to allow rotation of the control stop on a 90 angle using its handle 276. The arcuate width of slot 232 is substantially greater than the width of stop 27% to allow bracket movement with respect to the special stop 27%, for taking repeated bites on the jack using handle 2%.

it will be observed that surface 23% of stop 276 is displaced from the rotational anchoring shank 272 a greater distance than surface 232 which is removed 90 from surface 28%. Consequently, by rotating stop 270 using handle 276, either surface Ziih or surface 282 may be alternatively placed to abut the end surface 2% of slot 232 in bracket 2%, thereby limiting the arcuate bracket movement to two different values. The operation will be more specifically described hereinafter.

Positioned beneath slot 2% is a chain hook catch 2% as previously, to anchor the chain and prevent it from moving when a load is applied thereto.

Mounted to post 202 by pivotal elements 3% is a special U-shaped cam 3&2 having its legs straddling the post for pivotal connection thereto, and having a special toe with a curved concave frontal surface especially adapted to interfit with one of the chain rollers 3% as shown in FIG. 12. When rotational camming element 3232 is pivoted to its down position on orientation (as illustrated in FIG. 9), it is out of engagement with the roller chain. When, however, the pivotal cam is rotated upwardly to a position toward horizontal (i.e. clockwise in the form of the invention illustrated in FIG. 9), the concave surface on toe 394 engages one of the rollers (as illustrated in FIG. 12) to push the roller chain outwardly away from the post 262 and around hook catch 298 as the chain lifts the cam, to allow the chain to move in a reverse direction for lowering a load on the end 220' of the chain. The cam 25% includes an car 310 projecting therefrom for engagement with a stop bar 312 protruding from the post 262. Engagement of this car 31% with the stop bar 31.2 limits the upward movement of the cam element 392 and thus of toe 304 to a position below the horizontal plane. At this position the roiler chain is moved past the catch 298 sufiiciently to allow one roller link to move past the catch. At this time, the mechanism allows the next adjacent roller link to become engaged with the catch, as the weight of the load upon the chain automatically pulls the chain out of engagement with the concave toe 3%, allowing the camming element 362 to drop down to its downwardly biased position by its Weight.

When a load is to be raised on the end 22! of the roller chain by the jack assembly, as illustrated for example by the arrow in FIG. 8, the handle 2% is first rotated clockwise (FIG. 8) with respect to bracket 204 to disengage the eccentric surface 246' from the roller chain. The handle is then raised further to rotate bracket Ztld with respect to post 2% and around pin 214 to enable a bite to be obtained on the chain. The handle is then lowered in the bracket to cause the eccentric surface 240' to engage between two of the rollers of roller chain 220. Depression of the handle from the position illustrated in solid in FIG. 8 to the handle axis shown by the phantom line 2% in FIG. 8 forces the roller chain around sprocket 210 with rotation of the sprocket on pin 212. This causes an adjacent roller link to move around the slightly downwardly curved ear catch 2% and catch thereunder. This hoists the item the length of one chain link.

When something is to be thus hoisted, control stop lever 27% is pivoted on its shank 212 so that handle 276 protrudes outwardly away from the jack assembly at approximately as shown in FIG. 8. At this position, the stop surface 2% (FIG. 9) is in a position to abut surface 2% of slot 232 of bracket 2% (FIG. 9).

It will be seen that tooth 260 positively engaging slot 262 in post N2 prevents surface 290 in slot 232 of the V viewed in FIG. ll).

. bracket from rotating stop 279 and pin 212 when force is applied therebetween, as it would if this positive engagement of tooth 26%) with its respective slot 262 were not present. 7

The phantom line illustrated in FIG. 8 at 2% is the lowermost position of handlezlld when hoisting something, since contact of surface 23% with surface 2% limits the downward handle movement. At this position, the lower edge of bracket 2% is not low enough to form'an operative abutting engagement with car 318 on cam 3&2. Thus, to take another bite on the jack and hoist the mechanism one further link, the handle is lifted again to move eccentric surface 246' out of engagement with the roller chain and then rotate bracket 264 on pin 2E2 with respect to post 202. The handle islowered again. This process is repeated until the article is at the desired height. I

To lower the article on the jack in a closely controlled manner, first control stop 27% is rotated 90 so that book 276 lies alongside bracket 204 (as illustrated in FlGS. 9, 10 and 11). In this position, the contacting surface of the stop is 282 to abut surface 290 of slot 232 atthe lowermost position of the handle. It will be noted that since surface 282 is substantially closer to the pivotal axis of the shank of stop 2'70, bracket 2% maybe rotated counterclockwise further than it could when hoisting something. This puts the haudleand bracket in a lower position. Y

To lower'an article, therefore, the handle is first placed in the position illustrated in FIGURE 10 to put bracket Ell-'2 in the position illustrated in FIGURE it), usually almost vertical. The'handle is then lowered to rotate the bracket and cause its lowered edge to contact ear 3E8 of special, rotational, U-shaped chain shifting earn 302 (FIG. 11).

face 304 on the toe of the cam is in operative engagement with one of the rollers 306 on the chain'as shown in FIG. 12. Lifting of the handle to move the eccentric 246 out of engagement with the chain, thereby allows the force on the chain to move the chain and cam slightly upwardly. The upward movement of this portion of the 1 chain (see'arrow in PIG..11) causes the roller to carry out of'engagemcnt with its holding catch 29% until one of the roller links passes by the hook. Further, rotation of thechain and cam 36:2 causes engagement of car 31% with stop 312 so that the weight of the load on the chain forces the chain to disengage from the slightly concave surface to toe 334. This enabiesthe cam 392 to drop down against the post, and allow the chain to move inwardly again so that'the next roller link engages behind the catch After the chain has moved past the hook one link, this process is repeated again and again by merely lowering the handle again to rotate the cam 382 outwardly into engagement with the next adjacent link, etc.

It has been found that the novel jack works completely dependably and effectively for hoisting automobiles, and buildings, as examples. It has remarkable leverage to enable its use safely and efiectively wherever desired.

Various additional modifications of the apparatus, withv in the inventive principles taught may be apparent to those in the art upon studying the foregoing forms. These At this position the concave surof said sprocket and including hoisting means on one end; a bracket extending'above said sprocket and adapted to oscillate on said support; an eccentric rotatably mounted on said bracket adjacent said sprocket and chain; said eccentric having a lobe movable into engagement between adjacent rollers of said chain on said sprocket; handle "leans protruding from said eccentric enabling movement of said lobe into engagement Withsaid chain with further rotation of said eccentric causing shifting of said chain around said sprocket; chain catch means on said support to hold said chain in its shifted position; a rolling clement between said bracket and a portion of said eccentric opposite said lobe; said rolling element being movable to a first position to bind between said bracket and eccentric when said eccentric is shifted into engagement with said chain to thereby cause said eccentric, handle, and bracket to shift together, and movable to a second position to be free from binding when said eccentric and chain are out of engagement, to allow said handle and eccentric to shift with respect to said bracket.

2. A hoist mechanism comprising: a support; a sprocket rotatably mounted on said support; a hoisting roller chain around said sprocket; an eccentric mounted adjacent said sprocket and chain and adapted to be shifted into engagement with 'said chain between adjacent rollers thereof to shift-said chain around said sprocket; a handle on said eccentric; catch means on said support adapted to secure said chain when shifted; and release means mounted on said support, and operably associated with said handle and 'shiftable therewith to release a section of said chain from said catch means with each oscillation of said handle I to allow reverse movement of said chain on said sprocket.

3. The mechanism in claim 2 wherein said catch means is a hook, and said release means is a biased pin adapted to move under rollers of said chain when shifted, to shift them ofi said hook.

4. The apparatus in claim 3 wherein said pin is shiftably actuated by actuating means on said handle.

5. The apparatus in claim 4 wherein said actuating means is a magnet on said handle in operative relation to I said pin to actuate said pin and release rollers of said chain one by one around said hook.

6 A hoist mechanism comprising: a support; sprocket means on said support; a roller chain around said sprocket means; manual chain shifting means including a handle; chain catch means on said support in operative engaging relation to said chain; means on said support, shiftable to release said chain from said catch means; and a magnet on said handle positioned to shift and actuate said release means.

7. A hoist mechanism comprising: a support; 'a sprocket rotatably mounted on said support; a hoisting roller chain around said sprocket; an eccentric mounted adjacent said sprocket and chain, positioned adjacent said chain, and movable toward and away therefrom to be shifted into engagement with said chain between adjacent rollers therei of to shift said chain around said sprocket; a handle on said eccentric to shift it; catch means on said support adjacent said chain to engage and secure said chain when the chain is shifted by said eccentric and handle; and release means adjacent said catch means, operable with movement of'said eccentric and operably engageable with said chain to shift and release a section of said chain from said catch means with each oscillation of said handle and eccentric to allow reverse movement of said chain on said sprocket; said release means comprising a cam element pivotally mounted to said support and engaging sai roller chain only temporarily to shift it out around said catch means and being configurated to be releaseable therefrom after shifting said chain out around said catch means, to return to its initial position.

8. A vehicle jack comprising: a vertical support; a

sprocket rotatably. mounted adjacent the top of said support; a roller hoisting chain adapted to pass over the top of said sprocket; a bracket extending above said sprocket and adapted to oscillate on said support; an eccentric rotatably mounted on said bracket adjacent said sprocket and chain; said eccentric having a lobe movable into engagement between adjacent rollers of said chain on said sprocket; handle means protruding from said eccentric enabling movement into engagement with said chain, and rotation of said eccentric causing shifting of said chain around said sprocket; and chain catch means on said support to hold said chain in its shifted position; a chain release cam element pivotally mounted to said support and having a chain engaging surface; said cam element being engageable by said bracket to rotate the cam element into operative engagement with said chain to release the chain temporarily from said catch means.

9. The jack in claim 8 wherein a variable control stop is positioned between said bracket and support and mov- 1% able between first and second positions therebetween to cause binding therebetween and hoisting action in said first position of said stop, and to release the binding condition therebetween and cause lowering action in said second position.

FOREIGN PATENTS 17,616 11/90 Great Britain.

WILLIAM FELDMAN, Primary Examiner.

MILTON MEHR, Examiner.

Claims (1)

1. 2. A HOIST MECHANISM COMPRISING: A SUPPORT; A SPROCKET ROTATABLY MOUNTED ON SAID SUPPORT; A HOISTING ROLLER CHAIN AROUND SAID SPROCKET; AN ECCENTRIC MOUNTED ADJACENT SAID SPROCKET AND CHAIN AND ADAPTED TO BE SHIFTED INTO ENGAGEMENT WITH SAID CHAIN BETWEEN ADJACENT ROLLERS THEREOF TO SHIFT SAID CHAIN AROUND SAID SPROCKET; A HANDLE ON SAID ECCENTRIC; CATCH MEANS ON SAID SUPPORT ADAPTED TO SECURE SAID CHAIN WHEN SHIFTED; AND RELEASE MEANS MOUNTED ON SAID SUPPORT, AND OPERABLY ASSOCIATED WITH SAID HANDLE AND SHIFTABLE THEREWITH TO RELEASE A SECTION OF SAID CHAIN FROM SAID CATCH MEANS WITH EACH OSCILLATION OF SAID HANDLE TO ALLOW REVERSE MOVEMENT OF CHAIN ON SAID SPROCKET.

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