US1344117A

US1344117A - A corpora

Info

Publication number: US1344117A
Authority: US
Publication date: 1920-06-22
Anticipated expiration: 1937-06-22

Description

C. W. RIPSCH, l. C. DAWLEY AND C. D. DERBY.

LIFTING lACK.

APPucATloN r|Lcn1uNE9.19|9.

1,344, 1 17. Patented J ue 22, 1920.

4 SHEETS--SHEET l.

` ATTORNEY c. w. R|PscH,1. c. DAWLEY AND c. D. DERBY.

LIFTING JACK.

APPLICATION FILED JUNE'EI, 1919.

Patented June 22, 1920.

4 SHEETS-SHEET 2.

IN VEN TOR. CHW/FAES i0/- /P/PsC/f owzfs Z7- PATE/V Y ./wc.: c Dv ATTORNEY C. W. RIPSCH, J. C. DAWLEY AND C. D. DERBY.

LIFTING JACK.

APPLICATION FILED I IINE 9, 1919.

1 ,344, 1 1 7. l Patented June 22, 1920.

4 SHEETS-SHEET 3.

Fey. 3

C. W. RIPSCH, l. C. DAWLEY AND C. D. DERBY.

UFTING JACK, APPLICATION F'ILED )UNE 9, 1919.

Patented June 22, 1920. 4 SHEETS-SHEET 4.

i I n o n m S BY Jws:

' l ATTO 'Nm/ UNITED STATES PATENT OFFICE.

oHAnLns w. mysan, JAMES O. DAWLEY, ANI)k CHARLES D. DERBY, or DAYTON, OHIO,` AssIeNoRs To THE JOYOHCMDLAND COMPANY, or DAYTON,v OHIO, Av CORPORA-` TION or OHIO.

Appiication'iea :rime a, 1919. serial No. 302,861.' y

To all whom t may concern:

Be it known that .we IHARLES WrRirscH 7 3 JAMES (.5. DAwLEY,and CHARLES D. DERBY,

The object of the invention is to provide` a device of this'lrind having improved con trolling means whereby the load, as fit descends by gravity, will at'alltimes be under the full control of the Operator.

A further object of the invention is to provide a device of this'kind in which "the downward movement of the load will be retarded by the thrust, or frictional contact, of the controlling devices` which will absorb so large a part of the power exerted thereon by the load that, little power will remain to be overcome by the braking device.

A furtherv obj ect of the invention is to provide a device of this kind Iwhich rwill be simple in its construction and Operation, will comprise but a small number of parts, and will be of a very strong, durable character.

Other objectsl ofthe invention will appear' as the mechanism is described in detail.

In the accompanying drawings Figure l is a sido elevation of a lifting jack embodying our invention; Fig. 2 is a vertical section, with the lower partk of the ]ack in elevation; Fig. 3 is a plan view of the Vjack partly in section,.the section beingtaken on the line 3-3 of Fig. 2; Fig. l is a side eleva` tion of the, upper part of the jack with the end plate removed to show thebraking devices in elevation; Fig. 5 is a sectional view taken on the line 5-5 of Fig. 2; and Fig. 6 is a sectional view taken on the line of Fig. 4:.

In these drawings we have illustrated one embodiment of our invention and have shown the same as applied to a lifting jack of the screw Operated type. It will be understood, however, that the jack hereshown has been chosenfor the purpose of illustration only, and that the invention may be em! bodied in jacks of various kinds.

Specification of Letters Patent. i Pgptnted June f LLIETING-JAOK.`

Y The jack here illustrated comprises ab'ase .1, secured to which is an upwardly extending hollow standard 2 having mounted in the upper end thereof a nut 3, which, in the y present construction, is formed separate from the standard and is held against rotation relatively to the standard by means ,of lugs f1 extending through recesses in the upvper end of the standard. `Mounted in the nut 3 and extending lengthwise ofthe standard is a screw 5 which constitutes the lifting element of the jack. Mounted on the upper end of this screw is a .work engaging device or cap 6 upon which the load is supported.l

Secured to the cap 6 is a downwardly extending housing or sleeve 7 which incloses the standard 2 and engages the same to guide the work supporting cap 6 and maintain the same in proper alinement with the v screw. The lugs 4 of the nut 3 extend outwardly beyond the standard 2 into the path of the `lower portion of the sleeve 7, which fits the standard snugly, and actas stops to limit the upwardmovement of the sleeve. Mounted onV the screw 5 above the upper end of thestandard 2 is a beveled gear 8 which is here shown as rigidly secured to a reducedy upper end` portion or pintle 9 of the screw. second beveledgear 10 mounted'on the inner end of an operating shaft 1l' which is journaled in a suitable Vbearing 12 formed in aA plate 13 which closes an openingfin the side wall of the housing 7. Secured to the plate 13 and extending laterally therefrom is a casing 14; having a transverse partition 15 in which is formed a'secondbearing 16 for the operating'shaft 11. TheV Outer end of the casing 14; is closed by a removable cover or end plate 17. The end of the operating shaft 11 extends beyond theend plate 17 and has secured thereto a ratchet wheel 18 which lis acted upon by a pawl 19 carried by a lever 2O pivotally mounted on the end of the shaft V1l, to rotate the shaft, and through the mef dium of the beveled gears 10 and 8 to rotate the lifting screw 5. An anti-friction thrust bearing 21 is interposed between the beveled gear 8 and the loadv supporting cap 6 to per- The beveled gear 8 meshes with a e mit the screw to rotate freely relatively to the load. i y

The pitch of the thread of the screw 5 is such that when unrestrained the screw willV be rotated by the weight of the load and perm-it the latter to move downwardby gravity. It is necessary, however, that means beV provided for lcontrolling this downward movement of the load and, to accomplish this, we have .provided controlling mechanism which will be automatically connected with the lifting element when the latter moves downwardly and will retard its downwardy movement.' This retardingA or power' absorbing action will result from the end thrust orfrictional contactof the controlling'elements and, further, thecontrolling elements are of such a .character that the power will be very largely .absorbed by them and little remain to be absorbed or `overcome by the braking devices. As here illustrated7 the controlling devices comprise a worm wheel 22 loosely mounted on the operating shaft 1l and 'adapted'. to-be connected thereto by a one way clutch, thatV a non-circular portion of the shaft, as shown at'25. The teeth ofthe'two clutch members are so ai'rangedthat the worm Vwheel will 'be connected with the shaft only when the latter is rotated in a reverse direction, that is, when the lifting element moves down rvardly.` Then the operatingshaft is actuated-to impart lifting movement Yto the lifting element, the teeth of the movable clutchmember will ride over the teeth of that clutch member which is secured to the wornr wheel without imparting movement thereto. Any suitable means may be proyvided for holding the movable clutch memberyieldingly in engagement with the fixed clutch member and, in the present instance, weV have employed a plurality of springs 2G, one only of which is here shown, mounted in recesses inthe partitionland provided with balls 27 which bear against the flange lilre outer portion of the clutch member 24.-

The worm wheel Q2 meshes with a worm 2S which is rigidly mounted on a shaft 29 carried by the side walls of the casing 14 and provided with an anti-friction thrust bca-ring 30. The teeth of the worm wheel 22 and the spiral of the worm 28 are set at such angles that the worm wheel will rotate the worm when downward movement is imparted t'o the lifting element or screw 5. This angle, however, is only slightly beyond the` angle at which the worm would lock the worm wheel against rotation and, consequently, the worm will exert a very decided retarding action upon the'movement vof the worm wheel and will absorb a great deal of the power applied to'thatwhe'el by the load on the'lifting element. lMounted for rotation about the axis of the worm 2S and conknected therewith is a second worm wheel 31 which, in the present instance, is mounted on the shaft 29 which carries the worm wheel 28 and has its hub provided Vwith recesses 32 to receive tongues on the hub of the worm, and thus connect the worm wheel rigidly with the worm. 3l meshes with ay second worm 33l which is secured to a shaft 34 extendingat right anglesto the worm shaft 29 and` journaled in the plate 13 and partition llof the casing la, This shaft also is provided with an anti-friction thrust Vbearing Thev teeth of the worm 3l and the `spiral of the worm 33 are set at 'suchangles that; the wormwill be rotated by the worm wheel but willie);` ert a retarding actionon the movement of the worm wheel and will absorb a large part of the power applied thereto. Connected with the worm are-suitable braking devices which, as here shown, comprise a friction drum 36 rigidly secured tothe vshaft 34, between the partition l5 and the end plate 17.. Cooperating with the friction drum 36 are twobrake slices 37 which are carried byv intersecting arms 38 pivotally mounted on a stud 39r carried by the partition l5. The arms V38 project some distance beyond their axes 39 and are acted uponr by a spring l0 which-tends to move them toward each other and to thus cause the brake slices 37 to frictionally enga-ge the drum 36. This braking Iaction is-suiiicient to overcome any power which rmay be applied to the brake drum through the worms and worm wheel,

and will serve to lock the controlling mech;

anism against movement and thus hold the lifting element against downward movement. To permit the downwardmovement of the lifting element the controlling mechanism is released by moving the arms 3S away from each other. against the tension of the spring 1-O, and thus relieving the frictional contact between the brakeishoes and the brake drum.. This maybe accomplished in various ways but, as here shown, I have interposed between theV arms 38 a cam member 4l which, the present instance, comprises the flattened end of a stud 42 which is rotatably m `iunted in thewall of the casing 14 and has secured to its outer end lan actuating lever 43 by means of which it may be rotated and caused to spread the arms 38. The interior of the casing lftiforms a lubricant receptacle so that a part of the controlling mechanism may 'run in an oil bath and thusprovide ample lubrication for all of theY controlling mechanism. The casing also forms va dust proofl housing for the mechanism. l

The rworm wheel' llO -that wheuthe load whichhas been elevated 4is to be lowered this is accomplished automatically by merelyV manipulating the braking devices to release the controlling mechanism. When the controlling mechanism has been thus released,`the rotation of the screw 5, which is brought about by the downward movement of the load', will impart rotatory movement to the shaft ,l1 in a reverse direction, thus causing this shaftv to pick up,

and impart rotatory movement to theworm wheel 22. Because of the angles at lwhich the teethrof the worm wheel and the spiral ofthe worm 28 are set, the worm wheelwill impart rotatory movement to the worm, but, because of the angle at which the spiral is set, the worm will imparta very decided retarding action tothe rotation of the worm wheel, and will absorb much of the power thus applied thereto'. This absorption of power is diie to the thrust on the worm and the frictional contact between the Vworm wheel and the worm. l The braking devices serve to control the rotation of the worm and thus regulate the speed at which the load is lowered. 1n the present'instance a second worin" wheel and worm are interposed between the first worm and the braking devices. rllie retarding and power absorbing action of the controlling` mechanism does notinlany way depend upon theV inertia ofthe mechanism, and in this way distinguishes from and is a marked improvement upon th at type of controlling device in which an extended train of multiplying gearing is employed to transmit the power from the load to the braking devices. Vlith such .a train of gearing-,the retarding action is reduced as the train of gearing gains momentum, and the cfiiciency of the device is thus likewise reduced. Vith thepresent devicelthe parts of the controlling mechanism acquire the worms has a constant and effective retarding z ction upon the rotation of the op.-` erating shaft. It will also be noted that the construction is of "such a character that it requires the use ofa very small number of parts, and that these parts are such that they may be made of `a very 'strong durable cha actciz i i While we haveshown and described one embodiment of our invention, we wish it to be understood that we do not desire to be limited (othe details of construction thereof, as various modifications may occur to a person skilled in the art. y

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent is:

l; In a lifting jaclnia liftingmember, a shaft operatively connected with said lifting member, a worm wheel mounted on said shaft `and adapted to be rotated thereby when said shaft is rotated by thedownward.

movement of said lifting member, a worm meshing with saidv worm wheel-and havino its spiral so arranged that said. worm will be rotated byfsaid worm wheel', a second worm .wheel connectedwithsaidworm for rotation therewith, a worm meshing with and adapted to vbe rotated by the last men- -tioned worm wheel, and a braking device connected with the last mentioned worm.

2.,'In a lifting jack,y a lifting member, a shaft operatively connected with said lifting member, a worm wheel mounted on said shaft and adapted to be rotated thereby` when said shaft is rotated by the downward movement of said lifting meniber,a worm meshing with said worm` wheel and having itsspiral so arranged that said worm will be rotatedby said worm wheel, a shaft for said worm, a

worm lwheel mounted on .said shaft and rigidly connected with said worin, a second .worm meshing with and adapted to be ro# tated by the lastmentioned worm wheel, a braking devicecomprising a member rigidly connected with the last mentioned worm,

friction devices coperating with said braking member, and manually operated means to control said friction devices.

3. In a lifting `yack, a lifting member, a'

worm wheel, means to connect said wormV wheel with said lifting member when the latter moves downwardly, a worm meshing with and :rotatable by said worm wheel, a second worm wheel connected with said worm for rotation therewith., a second worm operatively connected with and rotatable by said'second worm wheel, and a braking device connected with said second worm. f

4l. In a` lifting jack, a lifting member, a worm wheel, means to connect said worm wheel with "said lifting member when the latter moves downwardly, a worm meshing with said worm wheel and having its spiral set at an angle just Ybeyond the locking position, a worin wheel connected `with 'said worm, for rotation about the axis thereof, a second worm meshing withand rotatable by said lastl mentioned worm wheel, and brak# ing `devices connected with the last mentioned worm. u

5. ln a lifting jack, a lifting member, an

'operating shaft connectedpwith said lifting said shaft and rigidly connected with said worm, a shaft extending parallel with saidy operating shaft, a second worm mounted on said shaft and meshing with and rotatable by said second worm wheel, a brake member secured tothe last mentioned shaft, friction devices cooperating with said-brake member, and manually controlledmeans for manipulating said friction members. f

6. In a lifting jack, a lifting member, a worm wheel, means to connect said worm wheel with said lifting member when the latter moves downwardly, a worm meshing'with and rotatable by said wormwheel, braking devices to control the rotation of said worm and comprising a friction drum, a pair of intersecting arms mounted adj acent to said friction drum, brake shoes carried by the respective arms,.and arranged to engage said friction drum, a spring actingon said arms to move said brake shoes into rengagement with said friction drum, a cam to move said armsone from the other against thel tension of said spring, and a lever connected with said cam.

7. In a lifting jack a lifting member, a pair of intermeshing members to retard the downward movement of said lifting member, means to connect one of said retarding members with said lifting member when the latter moves downwardly, a braking device connected with the other.V retarding member, said retarding members having their intermeshing parts arranged spirally of their respective circumferences and also having said intermeshing parts so arranged that the last mentioned retarding member will berotated by the first mentioned retarding member and a second pair of retarding devices interposed between the first mentioned retarding device and said braking device and having intermeshing parts arranged spirally of their respective circumferences and serving both to absorb power and to accelerate the speed ofA the mechanism at the braking device, and to thereby facilitate the control of said mechanism by said braking device.

8. In a lifting jack, a lifting member, a pair of intermeshing members to retard the downward movement of said lifting member, means to. connect one of said retarding members with said lifting member when the latter moves downwardly, and a braking device connected with the other 'retarding member, said retarding members having their intermeshing parts arranged spirally of their respective circumferences', and also having said intermeshing parts so arranged that the last mentioned retarding member will be rotated bythe first mentioned retarding member, and means interposed between said last mentioned retarding member and said braking device to further absorb the power transmitted to said retarding members by said lifting member.

9. In a lifting jack, a lifting member, a worm wheel, means to connect said worm wheel with said lifting member whenv the latter moves downwardly, a worm meshing with and rotated. by said worm wheel, a braking device, and means interposed between said worm'and said braking 'device to further absorb the power transmitted to said worm by said worm wheel.

10. In a' lifting jack, a'lifting member, a pair' of intermeshing members to retard the downward movement of said lifting member, means to connect one of said retarding members with said lifting member when the latter moves downwardly, a Abraking device connected withthe other retarding member, said retarding members having their intermeshing parts arranged spirally of their respective circumferences andy also having said intermeshing parts so arranged that the last mentioned retarding member will be rotated by the first mentioned retarding member, anda second pair of retarding ldevices interposed between the first mentioned Vretarding device and said braking device and having intermes'hing parts arranged spirally of their respective circumferences, and serving both to absorb power and to accelerate the speed of the mechanism at the braking device and to thereby facilitate the control ofsaid mechanism by .said braking device, a casing inclosing both pairs of retarding devices and ad'aptedto contain a lubricant, said braking device being arranged exteriorly of said casing.

1l. In a lifting jack, a lifting member, a worm wheel, a clutch to connect said worm wheel with said lifting member when the latter moves downwardly, a worm meshing with and rotated by said worm wheel, a braking device, means interposed between said worm and said braking device to absorb the power transmitted from said worm to said worm wheel, and a housing adapted to contain -a lubricant in `which one or more of said parts is wholly, or partially, immersed.

12. In a lifting jack, a lifting member, a shaft operatively'connected with said lifting member, a worm wheel mounted on said shaft and adapted to be rotated thereby when said shaft is rotated by the downward movement of said lifting member, a

member, a shaft Ahaving geared connection movement thereof, and meansl for control- With Said actuating member, an operating 1in@ fsaid retardingdevice.

device connected with said Shaft to impart Ion. testimonywhereof, We aiix our signa- 10 lifting movement toV said actuating member, tures hereto. v e f a device arranged adjacent to said operating 'l CHARLES W. RIPSCH. device and connected with said rotatable Y JAMES C. DAWLEY. actuating member to retard the downward v CHAS. D. DERBY.