US1874357A - Jack - Google Patents

Description

Aug. 30, 1932. w RUNYAN I JACK Filed Jan. 14. 1929 [IVVENTOR A TTORNE Y I made and assembled.

Patented Aug. 30, 1932 UNITED STATES GOMIANY, OF DAYTON, OHIO, A CORPORATION OF OHIO JACK Application filed January 14, 1929. Serial No. 332,322.,

' lifting jack having a threaded lifting member which is yieldingly held against rotational movements while it is moving upwardly or downwardly but in which the restraining efi'ect upon'the lifting member is automatically decreased at a limiting position of the latter;

Another object of the invention'is the provision of a double screw lifting jack which is simple in construction and easily and cheaply Other objects and advantages of the invention will be apparent from the following description and from the accompanying'drawing, in which y I V Fig. 1 is a central vertical section of a double screw invention; I v

Fig. 2 is a vertical section through the jack standard on the line 2'-2 of Fig. 1;

Fig. 3 is a vertical section through the jack standard on the line 3--3 of Fig. 1;

Figs. 4. 5, 6 and 7 are sectional views of the jack at various points corresponding to the' line 4t4, 5-5, 6 6 and 77, respectively, of. Fig. 2; Fig. 4 showing the position of the restraining spring when the lifting screw has reached its upper limit of travel, Figs. 5 and 6 showing the lifting screw going upand down while positioned for resisting rotational movements, and Fig. 7 showing the screw'all the way down and free to turn. 1

As illustrating a preferred embodiment the invention is shown as incorporated in a double screw jack such as is used for balloon tires which require extra lift, but of course the. invention may be incorporated 'in other adaptations thereof As shown, the jack comprises a hollow standard 10, provided with a base 11. This standard is preferably a metal casting of integral construction, the lower body porti on 12 of which is connected to the top portion 13 in an integral manner by the connesting yoke portion 14.

Loosely mounted within the standard is a jack embodying the present hollow sleeve-like outer lifting member 15. This lifting member is externally threaded, and its outside diameter is such that it may PATENT OFFICE I 1 WILLIAM B. Bun an, or DAYTON, OHIO, AssI GNoR TO THE DAYTON MALLEABLE IRON freelypass through the circularbore 16 in y the upper portion of the jack and through the hollow passage 17 in the lower portion.

In threaded engagement with the external 7 screw threads on this lifting member is a collar or nut 18, this nut being held against endwise movement by the upper portion 13 of thestandard. The lower side of'this nut engages a suitable antifriction bearing or other thrust member 19 which rests on top of the lowerportion of the standard. Rotational movements of the nut 18 may be effected by an actuating member 20 rotatably mounted in the yoke 14., the inner end of this actuating member having suitable gear teeth 21 or the like engaging corresponding teeth 22 on the nut. The actuating mem ber 20 is preferably socketed at 23 so that an actuating rod may be readily inserted in the socket for remote operation. The outer lifting member 15 is internally threaded at 25 so that it telescopically receives the threaded inner lifting screw 26. This inner screw, like the outer screw 15, is of about the same height as the total over-all height of the standard so that when the'various parts are extended the lift of the jack exceeds the height of the standard. On'the top of the inner lifting screw 26 is fixed a suitable saddle 27 which is adapted to receive a load such as the'axle of an automobile.

It is desirable that meansbe provided whereby extension of the lifting members may had, when there i's no load on the jack. To this end means tending to cause relative rotation between the outer screw and the nut, is incorporated in the structure.

Near the lower end of the lifting member 15,

the latter is circumferentially grooved at 29 to receive av spring member 30. This spring member preferably comprises a turn or two of spring steel and takes the form ofa helical ring having an internal diameter approximating the outside diameter of the groove 29. Any suitable number of turns or fractional parts of turns of the wire may be employed to give the desired degree ofrestraining effect of this yielding member on the lifting member 15 to thus normally adequately restrain the'lifting member against rotational movements, although this restraining is preferably so limited in degree that it may be overcome in case of binding of any of the other parts. As shown the helix comprises a turn and a half so that the ends stick out in opposite directions. The standard is interiorly provided along opposite sides thereof with grooves 31 and 32 shown extending from top to bottom of the body portion 12 of the standard. These grooves each receives one of the spring ends 33-or 34 toeprevent rotation of the spring and guide it for vertical movement. The width of the grooves is such throughout the main part of their lengths, that when one spring end engages a side of its groove the other spring end is about midway between its groove sides.

The spring 30 isso wound or wrapped about the outside of the outer lifting member 15 that when the latter is rotated it tends to cause the spring to rotate with it. However, when the end 34 for example of this spring engages the abutment surface 35 of grooves 32 (see Fig. 5), the helix member 30 then tends to wrap itself more tightly about the lifting member 15 in gripping engagement therewith, and this will restrain rotational movements of the screw 15 in a. counterclockwise'direction. The result is that when the lifting member 15 is turned for example as shown in Fig; 5 in a counter-clockwise direction, and moving upwardly in the standard, the end 34 of the spring moves up along the abutment surface 35 and normally holds the lifting member from rotating about its own axis. When the lifting member is moved down into the standard, rotating clockwise as shown in Fig. 6, the end 33 of the spring helix 30 presses against the abutment side 36 of the groove 31, and the spring is thus rendered operative, but in a reverse direction, and tends to wrap itself more tightly about the lifting member thus similarly'exerting a holding effect upon the latter. The effect of this restraining spring is to cause an axial or rectilinear movement of the outer lifting member 15 without rotation, so that both lifting members move together axially out of the standardwhen the nut 18 is rotating. When the load is being lowered and the nut 18 is rotated in the reverse direction, the two lifting screws are revegsely moved downwardly into the standar The upper end of the groove 32 is shaped as shown in Fig. 3, being offset at one side as indicated at 37 so that after the end 34 of the spring rides up the abutment surface 35 to the offset portion 37 of the groove, it may then move over some little distance sufficient to enable the end 33 of the spring to engage the abutment surface 38 of the groove 31.

In other words when the spring reaches its upper limit of movement the abutment surface of the groove which has been causing the spring to grab or grip the lifting screw 15 is no longer engaged by the spring end and consequently the surface of the groove which was effective while the spring was rising, no longer operates on the spring to render it operative as a restraining means. The surface 38 of groove 31 is now pressed by the opposite end of the spring and such action does not tend to cause the spring to grip the screw but on the contrary tends to cause the spring to be relieved of its pressure against the screw so that the screw is permitted to turn without substantial restraint. A stop pin 40 in the threads on the outside of the screw 15 engages the bottom of the nut 18when the screw 15 is elevated, so as to positively prevent any further upward movement of the screw. Continued movement of the nut at this time therefore turns the screw so that the inner screw 26, which is prevented from rotating about its own axis by reason of its engagement with the load, thus screws up out of the lifting screw 15 to cause the further elevation of the load.

When the nut 18 rotates so as to cause a lowering of the load, the lifting member 15 tends to rotate clockwise as viewed in Fig. 4, and therefore the spring end 33 is carried around to engage stop surface 36 of groove 31 resulting in the imposition of restraint on screw 18 normally preventing it from rotating about its own axis.

After the full retraction of the member 15 into the standard, should the load still be taken by the jack, the inner lifting screw 26 must be retracted and therefore the arrangement is such that the restraint against rotational movements of the outer lifting member 15 is materially lessened so that the latter may readily rotate with the nut, and screw the inner lifting member 26 down until the load is released. The lower end of the groove 31 is therefore offset like the upper end of groove 32 as indicated at 42. It will now be clear that when the end 33 of the spring comes opposite the offset portion 42 it is carried around a slight amount by the rotating screw 15 so that the opposite end 34 of the spring is moved into engagement with the abutment surface 43 of the groove 32, this action immediately-relieving the spring from its tendency to grip the screw 15 so that the lattermay be rotated without material restraint upon further rotational movement of the nut 18. A stop pin 44 near the upper end of screw 15 definitely limits the downward movement of the screw when the end 33 of thespring is adjacent the bottom of the groove in which it is mounted. Should the collar or nut 18 be turned so as to tend to raise the jack screws, when the lifting member 15 is at its lowermost position, the end made and assembled.

Patented Aug. 30, 1932 UNITED. STATES WILLIAM B. RUNYAN, or DAYTON, OHIO, ASSIGNOR To run DAYTON MALLEAMBLE IRON PATENT OFFI'CIE COMPANY, OF DAYTON, OHIO, A CORPORATION OF OHIO JACK Application ,filed January 14, 1929. Serial 1T0. 332,322..

1 This invention relates to lifting jacks, and particularly to jacks of the multiple lifting type. V.

7 One object of the invention is to provide a I lifting jack having a threaded lifting member which is yieldingly held against rotational movements while it is moving upwardly or downwardly but in which the restraining effect upon the lifting member is automatically decreased at a limiting position latter.

Another object of the invention'is the provision of a double screw lifting jack which is simple in construction and easily and'cheaply Other objects and advantages of the invention will be apparent from the following description and from the accompanying drawing, in which- I Fig. 1 is a central vertical section of a double screw jack embodying the present invention i Fig. 2 is a vertical section through the jack standard on the line 22 of Fig. 1;

Fig. 3 is a vertical section through the jack standard on the line 3-3 of Fig. 1;

Figs. 4. 5, 6 and 7 are, sectional views of the jack at various points corresponding to the line H. 55. 6-6 and 7.7, respectively, of Fig. 2; Fig. 4.- showing the position of the restraining spring when the lifting screw has reached its upper limit of travel, Figs. 5 and 6 showing the lifting screw going up and down while positioned for resisting rotational movements, and Fig. 7 showing the screwall the way down and free to turn.

As illustrating a preferred embodiment the invention is shown as incorporated in a double. screw jack such as'is used for balloon tires; which require extra lift, but'of course the. invention may be incorporated in other adaptations thereof. o As shown, the jack comprises a hollow standard 10, provided with a base 11. This standard is preferably a metal casting of integral construction, the lower body porti on 12 of which is connected to the top portion 13 in an integral manner bythe connecting yoke portion 14.

Loosely mounted within the standard is a of the hollowsleev'e like outer lifting member 15. Thislifting member-"is externally threaded, and its outside diameter is such that it may freely pass through the circularbore 16 in the upper portion of the jack and through the hollow passage 17 in the lower portion.

In threaded engagement with the external 7 screw threads on thislifting member is a collar or nut 18, this nut being held against endwise movement'by the upper portion 13 of thestandard. The lower side of this nut engages a suitable antifriction bearing or other thrust member 19 which rests on top of the lowerportion of the standard. RO- V tational movements of the nut 18 may be effected by an actuating member 20 rotatably mounted in'the yoke 14:,the inner end of this actuating member having suitable gear teeth 21 or the like engaging correspond ing teeth 22 on the nut. The actuating member 20 is preferably socketed at 23 so that an actuating rod may be readily inserted in the socket for remote operation. The outer lifting member 15 is internally threaded at 25 so that it telescopically receives the threaded inner lifting screw 26. This inner screw, like theouter screw 15, is of about the same height as the total over-all height of the standard so that when thevarious parts are extended the lift of the jack exsaddle 27 which is adapted to receive a load such as the'axle of an automobile.

It is desirable that means 7 be provided whereby extension of the lifting members may be had, when there'is no load on the jack. To this end means tending to cause relative rotation between the outer screw and the nut, is incorporated in the structure. Near the lower end of the lifting member 15, the latter is circumferentially grooved at 29 to receive a spring member 30. This spring member preferably comprises a turn or two of spring steel and takes the form of a helical ring having an internal diameter approximating the outside diameter of the groove 29. Any suitable number of. turns or fractional parts of turns of the wire maybe employed to give the desired degree of restraining effect of this yielding member on the lifting member 15 to thus normally adequately restrain the lifting member against rotational movements, although this restraining is preferably so limited in degree that it may be overcome in case of binding of any of the other parts. As shown the helix comprises a turn and a half so that the ends stick out in opposite directions. The standard is interiorly provided along opposite sides thereof with grooves 31 and 32 shown extending from top to bottom of the body portion 12 of the standard. These grooves each receives one of the spring ends 33-or 34 tosprevent rotation of the spring and guide it for vertical movement. The ,width of the grooves is such throughout the main part of their lengths, that when one spring end engages a side ofits groove the other spring end is about midway between its groove sides.

The spring 30 is so wound or wrapped about the outside of the outer lifting member 15 that when the latter is rotated it tends to cause the spring to rotate with it. However, when the end 34 for example of this spring engages the abutment surface 35 of grooves 32 (see Fig. 5), the helix member 30 then tends to wrap itself more tightly about the lifting member 15 in gripping engagement therewith, and this will restrain rotational movements of the screw 15 in a counterclockwise direction. The result is that when the lifting member 15 is turned for example as shown in Fig. 5 in a counter-clockwise direction, and moving upwardly in the standard, the end 34 of the spring moves up along the abutment surface 35 and normally holds the lifting member from rotating about its own axis. When the lifting memher is moved down into the standard. rotating clockwise as shown in Fig. 6, the end 33 of the spring helix 30 presses against the abutment side 36 of the groove 31, and the spring is thus rendered operative, but in a reverse direction, and tends to wrap itself more tightly about the lifting member thus similarly exerting a holding effect upon the latter. The effect of this restraining spring is to cause an axial or rectilinear movement of-the outer lifting member 15 without rotation, so that both lifting members move together axially out of the standard when the nut 18 is rotating. When the load is being lowered and the nut 18 is rotated in the reverse direction, the two lifting screws are revegsely moved downwardly into the standar The upper end of the groove 32 is shaped as shown in Fig. 3, being offset at one side as indicated at 37 so that after the end 34 of the spring rides up the abutment surface 35 to the offset portion 37 of the groove, it may then move over some little distance suflicient to enable the end 33 of the spring to engage the abutment surface 38'of the groove 31.

In other words when the spring reaches its upper limit of movement the abutment surface of the groove which has been causing the spring to grab or grip the lifting screw 15 is no longer engaged by the spring end and consequently the surface of the groove which was effective while the spring was rising, no longer operates on the spring to render it operative as a restraining means. The surface 38 of groove 31 is now pressed by the opposite end of the spring and such action does not tend to cause the spring to grip the screw but on the contrary tends to cause the spring to be relieved of its pressure against the screw so that the screw is permitted to turn without substantial restraint. A stop pin 40 in the threads on the outside of the screw 15 engages the bottom of the nut l8'when the screw 15 is elevated, so as to positively prevent any further upward movement of the screw. Continued movement of the nut at this time therefore turns the screw so that the inner screw 26, which is prevented from rotating about its own axis by reason of its engagement with the load, thus screws up out of the lifting screw 15 to cause the further elevation of the load.

When the nut 18 rotates so as to cause a lowering of the load, the lifting member 15 tends to rotate clockwise as viewed in Fig. 4, and therefore the spring end 33 is carried around to engage stop surface 36 of groove 31 resulting in the imposition of restraint on screw 18 normally preventing it from rotating about its own axis.

After the full retraction of the member 15 into the standard, should the load still be taken by the jack, the inner lifting screw 26 must be retracted and therefore the arrangement is such that the restraint against rotational movements of the outer lifting member 15 is materially lessened so that the latter may readily rotate with the nut, and screw the inner lifting member 26 down until the load is released. The lower end of the groove 31 is therefore offset like the upper end of groove 32 as indicated at 42. It will now be.

clear that when the end 33 of the spring comes opposite the offset portion 42 it is carried around a slight amount by the rotating screw 15 so that the opposite end 34 of the spring is move'dinto engagement with the abutment surface 43 of the groove 32, this action immediately relieving the spring from its tendency to grip the screw 15 so that the latter'may be rotated without material restraint upon further rotational movement of the nut 18. A stop pin 44 near the upper end of screw 15 definitely limits the downward movement of the screw when the end 33 of the spring is adjacent the bottom of the groove in which it'is mounted. Should the collar or nut 18 be turned so as to tend to raise the ack screws, when the lifting member 15 is at its lowermost position, the end 33 of the spring 30 immediately is moved rotationally by the lifting screw sufliciently far to cause the opposite end 3430f the spring to press against the abutmentsurface 35 of groove 32, causing the immediate yielding restraint of the liftingscrew 15 against any further rotational movements.

By reason of the construction just de scribed, the load may be effectively raised, first by causing both liftingmembers to move axially with relation to the standard and without rotating on theirown axes. comparatively large outer liftingrnember therefore takes the heavy Weight of the load a during normal operation. When, however, excessively high lifts are required the smaller inner lifting member 26 becomes effective,

the outer lifting member 15 being at the upper limit of its movementin the standard under such conditions and rotating in the standard without substantial restraint; Relief of the restraining efli'ectwhich normally prevents rotation of the outer lifting member when the latter is at its upper or lower limiting position permits the jack to be more easily manipulated and lessens the physical labor involved. The restraint upon the outer lifting member 15, however, is at all times such that it may be overcome by physical force to permit rotation of the outer lifting member in the standard should other parts of the jack bind or for any reason be prevented from operating properly.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be 7 members comprising an interiorly threaded rotatable collar engaging the threads of the outer screw member, means yieldingly carried by the outer screw member for frictional rotation thereon and comprising a.

member slidably guided in the standard for restraining rotation. of and causing axial movements of the outer screw member upon rotation of said collar, said standard having means for automatically varying said restraining effect for rendering said yielding,

member ineffective at a definite positioning of the outer screw member.

2. A lifting jack comprising a standard, an exteriorly threaded outer screw member mounted in the standard, an inner screw memberthreaded 1n the outer screw member, means for elevating said screw The hollow prising. a spring ring on the lower end: of

said outer screw member having an. end portion adapted for cooperation with the stand-' ard to cause saidring to grip around the said screwv member for. yieldingly resisting rotational movements of the said screw member. I 3. A lifting jack comprising 'a hollow standard, an exteriorly threaded outer screw member mounted in the.standard,an inner screw memberthreaded in the outer screw member, means for elevatingv said screw members comprising an interiorly threaded rotatable collar engaging 'thethread's of the outer screw member, means yieldingly carriedby the outer screw members and com-. prising a spring member carried on the outside of said. outer screw member andhaving outwardly projecting. ends, said standard having means for restraining said spring vmember against rotation within the standard and'being formed at the upper and lower limiting positions ofthe outer screw mem= ber to effect the releaseof said spring from said outer screw member. a 1

-members comprising an interiorly threaded rotatable collar engaging the threads of the "outer screw member, means yieldingly carried by the outer screw'member andcomprising a spring helix provided on'the outer screw member and adapted to grip said outer screw member to resist rotational move: ments in either direction, and abutment means adapted to engage'an end of said spring helix to prevent said spring from gripping theouter screw member.

5. A. lifting jack comprising a frame, a liftingscrew in saidframe, a collar in threaded engagement with said lifting screw, means forrotating said collar, and a spring member extending around said lifting screw, said standard having an abutment adapted to be'engaged by an end ofsaid spring member to cause the spring member to wrap itself around thelifting screw in gripping engagement therewith.

6. A'lifting jack comprising a frame, a lifting screw'in said frame, an inner lifting member in threaded engagement with said lifting screw, means for rotating said lifting screw, .a spring member engaging said lifting screw and saidframe to yieldingly resist rotational movements of said lifting screw, and means providing for automatic decrease of the-restraining effect of said spring at a limiting positionof the outer screw member. 7; In a double screw lifting jack, outer

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