US1785069A - Adjustable jack - Google Patents

Description

Dec. '16, 1930. l c. ca BoUDl-:TTE 1,785,069

ADJUSTABLE JACK Filed April 16. 192B 7@ A@ ff www.

Patented Dec. 16, 1930 CORNELIUS G.

BoUDE'r'rE, or cLAmIMoN'r, NEW HAMPSHIRE, AssIc'Noa rr'o SULLIVAN MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS ADJUSTABLE JACK j Y Application led April 16, 1928. j' Serial No. 270,456.

This invention relates to adjustable jacks and more particularly to an adjustable roof jack especially adapted to use in mines.

An object of this invention is to provide an improved adjustable jack. Another object is to provide an improved adjustable jack which may be set up and taken down quickly and with facility. Another object is to provide an'improved adjustable jack having improved adjusting means of simple yet rugged construction and adapted to be .manufactured at relatively small expense.

These and other objects of this invention will, however, hereinafter more fully appear as the description proceeds.

In the accompanying drawing. there is shown for purposes of illustration one form which the invention may assume in practice.

In thisdrawingf- Fig. 1 is a side elevational view of the improved adjustable jack, parts being omitted to facilitate illustration.

Fi 2 is a longitudinally extending sectiona view taken substantially on line 2-2 of Fig. 1.

Fig. 3 is a perspective view of one of the pawl adjusting levers. j

Fig. 4 is a perspective view of one of the pawls. a 1

Fi 5 is an elevational view illustrating the jack set up inoperative position in a mine. f c

Inv this illustrative construction there 1s shown a jack 1 comprising a main tubular body portion 2 carrying at its upper end a member 3 having pivotally connected thereto at 4 an ad'ustable abutmentr or support engaging mem er 5 having serrations on its upper surface adapted to engage suitable blocking or the mine roof. As sho'wn, iixed as by rivets or other suitable attaching means adjacent the lower end of the tubular jack body. 2 is alianged collaror coupling 6, the flange of which rotatably supports a casing or housing 7. This housing has a central opening 8 within` which the lower end of the jack bodyprojects as shown in Fig. 2. Pivotally mounted on pins 9 carried'by the housing 7 are pawls or dogs lOengagelable with helically formed teeth 11 on an axially movable adjusting screw 12 extendingvthrough the central opening in the housing and telescopically arranged within the tubular jack body 2. This screw is provided at its outer or: lower end with an abutment engaging member or foot piece 13-having spaced points `14 for maintaining the adjusting screw 12 against rotative movement during adjustment of the jack. This foot piece is engageable with suitable blocking or the mine loor. i

As illustrated, arranged within the housing 7 are coil springs 15 acting on the pawls 10 `for yieldably maintaining the latter in engagementl with the teethV of the adjusting screw. Suitable adjustable lugs or followers 16 are threaded intothe ousing and are adjustable to Vvary the tension of the coil springs. In accordance with this invention the pins 9 also have pivotally mounted thereon levers 17 projecting laterally Ythrough these lugs each have oppositely located abutment surfaces 21 and 22. The pawls 10 have similar abutment surfaces 23 and 24 formed by cutting away a portion of their bearing supports. It W1ll thus be seen that when the levers 17 are in the positionindicated in full lines in Fig. 2 the abutment surfaces 21 on the levers areA in engagementwith the abutment surfacesl 24 on Athe pawls 10, while when the levers are in the dotted line positon in that ligure the surfaces 22 and 23 on the levers and pawls respectively are in engagement. It will furtherv be seen that when the levers 17 are in the yfull line position shown in Fig.

.2 and are pressed inwardly toward one an- ,the operator first places the jack in the position shown in Fig. 5 and then presses inwardly on the levers 17 releasing the pawls 10 from engagement with the teeth on. the adjacklbody and the justing screw 12 thereby permitting the latter to slide downwardly until the foot piece 13 engages the blocking or the mine floor, the levers thereafter being released and the pawls automatically maintaining the jack in position. The operator then swings the levers 17 downwardly into the dotted line position shown in Fig. 2 and as shown in full lines in Fig. 5 and then bodily rotates the housing 7 relative to the tubular jack body thereby causing the pawls to act as a nut forcing the adjusting screw axially apart and as a result the jack is rigidly held in position, the pawls preventing separation between the adjusting screw and the jack body when the jack is so positioned. When it is desired to take down ithe jack the operator merely rotates the housing 7 thereby loosening the jack parts and thereafter releasing the pawls from the adjusting screw permitting the latter to be slid inwardly within the jack body, the pawls maintaining the adjusting screw in its retracted position.

As a result of this invention it will be noted that an improved adjustable jack is provided which may be adjusted expeditiously and with facility. It willfurther be noted that t-he adj ustin means for the jack is composed of a relative y few parts which are of simple yet rugged construction especially adapted to withstand the severe conditions of service and which may be manufactured at a minimum of expense; These and other uses and advantages of this invention will be clearly apparent to those skilled in this art.

While I have in this application specifically described one form which my invention may assume in practice, it will be understood that this form is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

WVhat I claim as new and desire to secure by Letters Patent is:

1. An adjustable jack comprising a body member carrying an abutment engaging member, a plurality of pawls carried by said body member, a helical screw arranged to telescope within said body member, spring means normally tending to hold said pawls in engagement with the threads on said helical screw, said pawls having means adapted to cooperate with said threads for effecting relative longitudinal movement of said body member and screw upon rotation of said pawls around said screw, and handle means adjustable relative to said pawls and movable into one position to effect release of said pawls from said threads to permit free collapsing of said jack, said handle means also being adjustable to another position wherein they project laterally to serve as leverage attainlng means for rotating said pawls around said screw.

rnection therewith handle members having a lost motion connection with said pawls adapted when swung toward said body member to engage said pawls and to move them out of engagement with said threads to permit free collapsing of said jack, said lost motion connection permitting said handle members to be swung to a position substantially at right angles to said screw to serve as means whereby the pawls may be rotated about said screw to effect adjustment of said jack.

3. An adjustable jack comprising a tubular body carrying an abutment engaging member, a helical screw telescoping therewith, a housing rotatably connected to said body member and surrounding said screw, a pair of pawls pivotally carried in said housing, a pair of springs acting on said pawls normally tending to hold them in engagement with the threads on said helical screw whereb rotation of said housin and pawls aroundy said screw will effect adjustment of said jack, and a pair of handle members pivotall mounted on the same aXis as said pawls and having a lost motion conwhereb they may be moved to one position to e ect release of the pawls from said threads and to another position at right angles to said screw to serve as means for rotating the housing and pawls.

4. An adjustable jack comprising atubular body member carrying abutment engaging means, a helical screw arranged to telescope within said body member, adjustable elements adapted to engage with the threads on said screw for effecting relative longitudinal adjustment between said body member and screw upon rotation of said elements around said screw, and handle means for adjusting said thread engaging elements and movable into one position to effect release of said thread engaging elements and into another position to provide lever means for rotating said thread engaging elements around said screw, said handle means in said last mentioned position permitting enga cment of said thread engaging elements with the threads of said screw.

5. An adjustable jack comprising a hollow body member carrying an abutment engaging means, a support rotatably mounted on said body member, a helicalscrew arranged to telescope within said body member, elements adjustably mounted on said rotatable support and movable into and out of engagement with the threads on said screw, and handle means adjustably mounted on said support and adjustable into a position for moving said thread engaging elements out of engagement with said threadslt'o permit free collapsing of. the -ack, said handle means also being adjusta le into a `position `to move said thread engagin elements into engagement with said threa s, said handle means being operative to effect rotation of said support relative to said body member to move said thread engaging elements about said screw toV effect relative longitudinal adjustment of the body member andscrew.

6.` An adjustable jack comprising a hollow body member carrying an abutment engaging means', a su port rotatably mounted on said body memI er, a helical screw arranged to telescope within said body member., pawls carried by said rotatable supportv and engageable with the threads of said helical screw, said pawls being adapted to cooperate with said threadsfor leffecting relative longitudinal movement of said body member and screw u on rotation of said support relative to sai body member, said support being rotatable to effect movement of said pawls around said screw, and handle means for releasing said pawls from engagement with said threads to permit free collapsing of said jack and for rotating said support relative to saidv body member to effect rotation ofsaid pawls around said screw. j

7 An adjustable jack comprising a hollow body member, a su port rotatably mounted on said body mem -r,`"a helical screw arranged to telescope within said body member, pawls pivotally mounted on said rotatab e support and adapted to cooperatewith the threads of said helical screw, andI meansy for rotating said support relative to said body member to effect movement of said pawls around said screw for adjusting said screw longitudinally relative to said body member including handle members pivotally connected to said support about axes coincident with the pawl axes and swingable relative to said pawls, said handle members also being operative to effect release of said pawls thev threads of said screw to permit free colla sing of said jack.

8. An adjustable roof jack comprising a tubular body -member, an adjusting screw telescopically received in said body member, said body member and screw having abutment engaging members normally preventing rotation of` said body member and screw when the jack is in operative position, and means for elfectin relative axial adjustment of said body mem er and screw to move said abutment engaging members apart to position the jack, and including a rotatable membei` carried by said body member, an element carried by and adjustable relative to said rof tatable member and forming a nut engageable with the threads of said screw, and means for adjusting said nut forming .elementmto and out of itsthread 'engaging position while said screw remains stationary with refspect thereto, and for rotating said rotatable member relative to said body member when.

said-nut forming element is in its thread entubular bo y member, an adusting screw,l

telescopically received in sai body member, said body member and screw having abutment engaging members normally preventing rotation of vsaid body member and screw when the jack is in operative osition,

ment of said body mem er and screw to move said abutment engaging members apart to position the jack, and including a rotatable member carried by said body member, an element carried by and adjustable relative Vto and means for electin relative axia adj ustsaid rotatable member and forming a nut env gageable with the threads of said screw, and means for yadjusting said nut forming element into and out of its thread engaging position while said screw remains stationary with respect thereto, and for rotating said rotatable m'ember relative to said body member when said nut forming element is in its thread engaging position to et'ect relative axial adjustment of said body member and` screw, said screw and body member when said nut forming element is released from the threads of said screw having free telescopic' movement to rmit collapsing lof the jack, and said nut orming element engaging the threads 'of said screw to form a` lock to hold said screw in its collapsed position.

In testimony whereof I aiiix my signature.

CORNELIUS G. BOUDETTE.

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