US1933777A - Lifting jack - Google Patents

Description

NOV. 7, 1933. wI A. TRAUT I 1,933,777

LIFTING JACK Filed Sept. 19, 1930 2 Sheets-Sheet 1 NGV. 7, 1933. W A TRAUT 1,933,777

LIFTING JACK Filed Sept. 19, 1930` 2 Sheets-Sheet 2 Patented Nov. 7, 1933 1,933,7*2'1 LrFTING JACK William A. Traut, 'Racine `Wis., assigner vto Walker Manufacturing Company, Racine,

Wis., a corporation of Wisconsin ApplicationVV September 19, 1930 Serial No. 483,042

10 Claims. (Cl. 25d-102) This invention relates to certain new and useful improvements in lifting jacks, and more particularly to a screw jack of the multiple extension type, designed to be capable of extension to more than twice the height oi the jack when in lowered or collapsed position.

The Vjack comprises three substantially cylin dricai members adapted to telescope within one another when in collapsed position. Means is provided for rotating the intermediate member, whereas the upper and lower members are linked together by extensible means so that both will be held from rotation when thev lower or supporting member is` resting upon the ground. Inter-engaging screw members housed within the cylindrical members cause the intermediate mernb r to be moved vertically within the lower member, the uppermember to be lmoved vertically within the intermediate member, whenever the intermediate member is rotated.

The general object of this-invention is to provide improved jack of the type brieily described hef -bove and disclosed more in detail in the specifications which follow.

Another object is to provide'a telescopic jack of the screw type in which all or the screw members are completely housed within the telescopic lifting members.

Another object is to provide an improved jack of this type Jrrr-which the members may be completely elevatec'for lowered even though no load is carried by the jack.

Another object is to provide impreved'means or fr ctionally resisting rotation of the intermediate or driving member.

Another object is to provide a jack of this type which is simple and economical to manufacture easily assembled.

Other objects and advantages of this invention will be more apparent from the `following detailed description of one approved form of jack built according to the principles of this invention. f

In the accompanying drawings:

Fig. 1 is a central vertical section through the jack in elevated or extended position.

Fig. 2 isa side elevation, partially in vertical ection, or the jack in lowered or collapsed position.

YFig. 3 is a horizontal section taken substan-l tially on the line 3 3 of Fig. 1.

Fig. 4 is a herisontal section taken substantially on the line 4 4 of Fig. l. f

end or head 17 of screw 12, this head 17 being Fig 6 is a perspective View oi the upper portion or" the upper `lifting memberywith the1ift-- ing cap removed. y

Fig. is a perspective View of the upper sliding key member. Y3 v Fig. 8 is a perspective view of the split or sectional ring cr collar used inthe top of the standard.`

The jack comprises a lower member Ain the form of a supporting base or standard, an up- 65 per lifting member B and an intermediate-lifting member C, the three membersA, B 'and C being stbstantially in the form of hollow, cylinders adapted to telescope within Vone another and forming a substantially closed'housing in any 70 g position of the jack. i

The lower or base member A comprises a main Y cast -g formed with anupwardly extending substantially cylindrical shell l enclosing a vertical cylindrical chamber 2 which extends through the 75.

upper Vend oi .the jacl: but isclosed at the bottom 3.' This closed bottom 3 extends. outwardly in the form of'a base plate4 which is reinforced by the vertical webs 5. Athickened annular portion or Vcollar 8 at the upper endof member A 80 is centrally recessed to receive a split spring locking ring 7, and at diametricallyy opposite points is provided with cylindrical openings. 8 to receive the cylindrical friction .plugs or disks 9. An internall annular shoulder or collar is 85 4formed by a split or sectional ring consisting of '15, the lower end oi this opening beingclosed by a suitable plug or closure plate 16. -The main bore 15 does not extend through the upper provided vwith a noncircular Opening to receive the vertically slidable post member 18. As'here' shown, post 18 is of hexagonal cross section and is sli'dable through a similarly shaped opening in head 17 so that the post 18 will at all times be held from rotation vby the stationary screw 12. A'crosspin 19v in the lower end 0i post 18 is adapted to engage thev lower face of head 17' andv limit vthe .upward movement oi the Vpost 18.

The intermediate member C 'comprises a hol- 110 Yat the lower end of member C is adapted to slidably engage Within chamber 2 in the lower member A. This collar 23 also engages the lower surface of split collar 10 to limit the upward movement of intermediate member C.

A hollow exteriorly threaded screw sleeve 24- is positioned coaxially within member C and is non-rotatably fixed thereto by being keyed at its lower end within the inwardly extending flange portion 22 as indicated at 25. The lower portion of sleeve 24 is internally threaded'to form a nut 26 which meshes with the lower fixed screw 12. The upper portion of sleeve 24, above the nut 26, is interiorly cylindrical as indicated at 27 so as tofreely telescope over the fixed screw12 when the jack is lowered.

The upper lifting member B is in the form of a hollow shell which is exteriorly cylindrical at 28 so as to telescope slidably and rotatably within the chamber or cavity 21 in the intermediate member C. The lower portion of member B is internally threaded to form a nut 29 meshing with the exterior threads on sleeve 24. The cavity or chamber 30 within the upper portion of member B is of any suitable non-circular cross section so as to non-rotatably but slidably engage with a key member 31 which is secured as by means of pin 31 to the upper end of post 18. In the form here shown, the key 31 is in the form of a hexagonal plate or washer, and vertically extending grooves 32 are formed in the otherwise cylindrical interior 30 of member B to engage with the corners of the hexagonal key 31. Any other suitable form of keying means may be provided so that the post 18 is permitted vertical sliding movement with relation to member B but relative rotation of these members is prevented. A load-supporting cap 50 is secured within the upper end of member B by any suitable means such as pin 51.

Any suitable means may be provided for rotating the intermediate member C in either direction. As here shown, an outwardly extending collar 33 at the upper end of member C is formed with an annular series of ratchet teeth 34. A pawl housing is formed of similar upper and lower plates 35 and 36 each comprising an annular portion 37 which fits in an annular groove 38, formed one at the top and one at the bottom of fiange 33. vAt one side the members 35 and 36 are extended to form a handle-receiving socket 39, the members 35 and 36 being secured together at each side of socket 39 as by means of rivets 40. A double armed pawl 41 is centrally pivoted on pin 42 riveted between the housing members 35 and 36, pawl 4l being formed with similar teeth 43 and 44 at its opposite ends adapted to engage alternatively with the ratchet teeth 34 on member C. A cam or finger 45 projecting rearwardly from the central portion of pawl 41 engages with a suitable leaf spring 46 mounted within the pawl housing. The pawl 41 is provided with similar oppositely extending fingers 47 and 48 by means of which either tooth 43 or 44 may be alternatively thrown into engagement with the ratchet teeth 34. The spring 46 acting against the cam 45 will hold this tooth 43 or 44 yieldably in engagement with the ratchet and permit it to ride freely overl the teeth 34 in one direction. A handle 49 may be detachably engaged within the socket 39. With the parts positioned as shown in Fig. 3, if handle 49 is oscillated about the central vertical axis of the jack, it will be apparent that the ratchet wheel 34 and intermediate member C will be intermittently rotated in a counter-clockwise direction. By properly manipulating one of the iingers 47 or 48, the other tooth 44 of pawl 41 could be thrown into engagement with teeth 34, whereupon a similar oscillating movement of handle 49 would impart an intermittent clockwise rotation to the intermediate member C.

In operation, assuming that the jack is in the collapsed position shown in Fig. 2, and that the reversing pawl 41 is properly positioned, oscillation of handle 49 will cause the intermediate member C to be intermittently rotated in such a direction that the nut 26 xed in the lower end of this member C will travel upwardly on the fixed screw 12 in standard or .base member A, thereby moving the intermediate member C vertically out of the standard. At the same time, the external threads of sleeve 24 (which rotates with the member C) will travel downwardly through nut 29 in upper member B thus causing this upper lifting member B to be moved upwardly out of theV intermediate member C.

The member B, and consequently the nut 29 fixed in the lower endthereor", will at all times be prevented from rotation by means of its nonrotatable but extensible connection with the base member A through key 31, post 18, and iixed screw 12.r This operation will continue until the jack reaches the extreme elevated position shown in Fig'. 1. Upward movement of intermediate member C is limited by the engagement of collar 23 at the lower end of member C with the split collar 10 fixed within the upper member of base member A. Upward movement of upper lifting member B is limited by the engagement of key 31 with the upper surface of nut-29 and the engagement of pin 19 at the lower end of post 18 with the head 17 in fixed screw 12. It will thus be apparent that the v telescoping cylindrical members A, B and C can -nct be entirely withdrawn froml one another after the jack is assembled, unless it is desired to disconnect the parts for repair' purposes.

The friction disks or plugs 9 not only serve to hold thesplit collar 10 in place and thus limit the upward movement of intermediate member C, but thesegplugs also irictionally engage the outer cylindrical surface 20 of member C at all times due to the pressure of spring ring 7. The frictional resistance thus offered is sufficient to hold the member C against rotation during the idle stroke of handle 49 while the pawl 41 is running over the ratchet teeth 34, and also serves to snugly hold the intermediate member C in position within the standardA at all times. The jack may be assembled by iirst mounting the fixed screw l2 within the base member A, and similarly mounting the xed screw sleeve 24 `within the intermediate member C. The intermediate member C is then inserted through the upper end of base member A'by screwing nut 26 downwardly upon the iixed screw 12. When the intermediate member C has been thus inserted a suiiicient distance within standard A, the sections of split collar 10 may be inserted within the upper end of standard A around the cylindrical surface of intermediate member C, andr the friction plugs or disks 9 inserted and locked in position by means of spring ring 7.

The member C is then screwed completely down Within the standard A, andthe member B (without Cap 50) is screwed down within member C about the sleeve 24. The assembled key 3l and post 18 are then inserted through the upper end of the collapsed jack members. The post will extend through the base plate 4 and the stop pin 19 is inserted in the lower end oi pest i8 and the post pushed bacia into the assembled jack and closure plate 16 secured in place. The cap 50 can now be secured in the upper end oi memberB, and the screw members are eompietee 1y enclosed.

It will now be seen that the jaolf: is in the form of a completely closed telescopio housing all times. All or the ser w members are oompletely housed within the telescopio eylind members, as is also the means for preve ting rotation of the upper lifting member B. 'lhere are no external sorew threads on any of the housing members A, B or C. rihis assembly may be partially filled with grease so as tobe selilubricating.

An old and well-known form of ratohet driv ing means has been disclosed for rotatig the termediate member C. While this means is entirely suitable for this. purpose, it will be under:- stood that any other suitable form oi drivin means could be substituted for imparting tn necessary rotation to the member C.

As long as the base member A is resting upon the ground or other suitable srppoimA so that it is prevented from rotation, the upper member B will also be prevented from rotationby the extensible means hereinabove described, so that the jack can be completely elevated or lowered without the presenoe or" any load upon the lift ing head 5G. This permits the jack to be easily adjusted beneath a load of any height (within the limits oi the jaoks lift), and permits the jack to be suihoiently lowered to permit its easy removal, even after the load has been disen gaged.

I claim:

1. A liftinCr jack Comprising upper, lower` intermediate hollow members, the lower mem ber being in the form of a supporting base and the upper member adapted to support said upper member telesooping slidably within the intermediate member and the intermediate member telesooping slidably within baM hollow members and connecting the upper member with the base member for preventing rotation of the upper member, means mounted on and moving vertically with t1 e interni diate members for rotating the intermediate iN nber, an internally threaded nut within the l er portion of the upper member, an internally and externally threaded screw sleeve fixed within the intermediate member and meshing within the nut, and an externally threaded screw fixer within the base member and meshing within screw sleeve.

2. A lifting jack comprising lower ane intermediate hollow members, the lower mem@ entendi a load.v

member, an internally and externally threaded sorew'sleeve fixed within theintermediate member and meshing within the nut, a hollow externally threaded screw fixed within the base member and meshing wi in the screw and an inner -post memberslidably but nonrotatably keyed at its respective .end portions within the hollow screw' and the upper hollow member.

3. A liiting` jack comprising uppenlower and intermediate hollow members, ythe lower kmember in the form oi' a. supporting` base and the upper member adapted to support a load, said intermediate member telescoping slidably and rotatably within the base member, andthe upper bei eleseopinor slidably and rotatwithin the intermediate member, meansior rotating the intermediate member, means housed within the hollow members for causing the vintermediate member to be moved vertioally'with relation to the base member and the upper Amember to be moved vertically with relation to the intermediate when the intermediate member sleeve,

is rotated, and means carried by the base mem member telesooping slidably and rotatably within the intermediate member,v means for rotat-V e hollow members' for Causing the e member to be moved vertically with ation to the base member the upper member to be moved vert ally with relation to the intermediate member when the intermediate member is rotated, a split oollar fitted within upper end of the base memb vabove the Collar on the intermediate member, there being mating openings in the basemeinber and split collar, friction plugs movably fitted in these openings, and a spring ring engaged about the plugs forcing-them yieldably into engagem ment with the external cylindrical surface oi the intermediate member. f

5. A llifting jack comprising a supporting d having a vertical oylindrieal'ohamber member teleseoping within saidv standard, said having a cylindrical enter.: r surface with an outstanding annular flange at its lower end adapted to extend within the chamber in the standard, means for rotating the iting member, means connued within the standard and lifting member for elevating or lowering the lifting member when the liiting member is rotated relative to the` standard, and means Carried by the standard for frictionally engaging the exterior surface of the lifting member above the annular flange.

6. A standard having a verticalv cylindrical chamber extending through the -top thereof, a lifting member teiesooping within said standard, said `Tting member having a oylindrical exterior Asurface with an outstanding annular flange at through the top thereof, a iiiting lli) lifting jack comprising a supporting the lifting member, means confined within the Standard and lifting member for elevating or lowering the lifting member when the lifting member1 is rotated relative to the standard, a split collar adapted to fit about the cylindrical surface of the lifting member above the annular flange thereon and within the upper end portion oi the standard, friction plugs movably positioned in mating openings in the upper portion of the standard and the split collar, and a spring ring secured about the plugs and holding them in yielding rictional engagement with the lifting member.

7. A lifting jack comprising upper, lower and intermediate hollow members, the upper member having a cylindrical external surface, a load supporting cap at the upper end of kthe upper member, an internally threaded nut xed within the lower end of the upper member, the internal cavity of the upper member above the nut being of non-circular cross-section, the intermediate member having a cylindrical exter nal surface with an outwardly projecting annular collar at its lower end, means carried by the upper end portion of the intermediate member for rotating the same, a hollow externally threaded screw-sleeve positioned centrally Within the intermediate member and fixed thereto at its lower end, said screw-sleeve meshing within the nut in the upper member, there being an internally threaded nut in the lower end of the screw-sleeve, the lower hollow member being in the form or" a supporting base having a cylindrical interior in which the collar at the lower end of the intermediate member is rotatable and vertically slidable, means carried by the upper end of the base member for frictionally engaging the cylindrical external surface of the intermediate member above the collar thereon, a hollow externally threaded screw iixed at its lower end in the base member and meshing within the nut in the intermediate member, a non-circular post member slidably iitted within an opening of similar cross-section in the upper end of the hollow screw, and a key member fixed to the upper end of the post and slidably but nonrotatably engaging within the non-circular cavity in the upper hollow member.

8. A lifting jack comprising upper, lower and intermediate externally cylindrical hollow members, the lower member being in the form of a supporting base and the upper member adapted to support a load, said upper member telescoping slidably within the intermediate member and the intermediate member telescoping slidably within the base member, means mounted on and movable vertically with the intermediate member for rotating the intermediate member,

a screw sleeve secured within and movable with the intermediate member and internally engaging the upper member, and extensible means housed within the hollow members and secured at its lower end to the base member and movably l engaging the upper member and screw sleeve internally for holding the upper member against rotation and causing the intermediate member to be moved vertically with relation to the base member and the upper member to be moved vertically with relation to the intermediate member when the intermediate member is rotated.

9. A lifting jack comprising upper, lower and intermediate externally cylindrical hollow members, the lower member being in the form of a supporting base and the upper member adapted to support a load,A said upper member telescoping slidably within the intermediate member and the intermediate member telescoping slidably within the base member, means mounted on and movable vertically with the intermediate member for rotating the intermediate member, a screw sleeve secured within and movable, with the intermediate member and internally engaging the upper member, and extensible means housed within the hollow members and'secured at its lower end to the base member and having sliding engagement with` the upper member and threaded engagement with the screw sleeve for holding the `upper member against rotation and causing the intermediate member to be moved vertically with relation to the base member and the upper member to be moved vertically with relation to the intermediate member when the intermediate member is rotated.

l0. A liting jack comprising upper, lower and intermediate externally cylindrical hollow members, the lower member being in the form ofv a supporting base and the upper member adapted to support a load, said upper member telescoping slidably within the intermediate member and the intermediate member telescoping slidably within the base member, means mounted on and movable vertically with. the intermediate mem- -ber for rotating the intermediate member, and

extensible means housed within the hollow members and comprising a plurality or^ members movably engaged with one another, one of the members being secured to the base member and one to the intermediate member, and the means being movably engaged with the upper member so that the upper member is held against rotation and the intermediate member is caused to move vertically with relationto the base member and the upper member to move Vertically with relation to the intermediate member when the intermediate member is rotated.

WILLIAM A. TRAUT.

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