US1681283A

US1681283A - Lifting jack

Info

Publication number: US1681283A
Application number: US48230A
Authority: US
Inventors: James C Dawley
Original assignee: Joyce Cridland Co
Current assignee: Joyce Cridland Co
Priority date: 1925-08-05
Filing date: 1925-08-05
Publication date: 1928-08-21
Anticipated expiration: 1945-08-21

Description

Aug; 21, 1928-.

J. C. DAWLEY LIFTING JACK 2 Sweets-shew Filed Aug. 5, 1925 A. TTORNE Y Aug. 21, 1928. i 1,681,283

J. C. DAWLEY LI'FTING JAcK.

Filed Aug. 5, 1925 2 sheets-sheet ,2

1N VENroR Jcwas cyan/ey B Y I ATTORNEY Patented Aug. 2l, 1928.

UNITED s-TArEs PATENT omer.

JAMES c. DAWLEY, or DAYTON, oHIo. ASSIGNQR To THnJoYcEcmnLANn COMPANY,

4or nAY'roN, onro, A coR-Pomi'iroivk or oH-Io.

LIFTING JACK.

nppiicaeon med August 5, 1,925. serial No. 48,230.

This invention relates to lifting jacks and more particularly to what is known as a self-lowering jack, in which the load moves downwardly under its own weight and its downward movement controlled by a fric tion brake.

The main object of, the invention is to rovide im roved means forcontrollingthe ibwering oi) the load, and to this end a further object is to provide means for locking the friction devices in operative position so as to positively hold the load against down-` ward movement.

A further object of the invention is to provide an improved one-way clutch for con# necting the lifting element with the brake.

A further object of the invention is to provide improved meansfor mounting the arms which actuate the friction members.

Other objects of the invention will appear as the device is described in detail.

In the accompanying drawings Fig. is a front elevation, partly in section, of a liftl ing jack embodying my invention; Fig.` 2 is a section taken on the line 2-2 vof, Fig. 1; Fig. 3 is a side elevation of the clutch, partly in section; Fig. 4 is a vertical section taken through the clutch of Fig. 8; Fig. 5 is an elevation of the supplemental housing with the cover plate. removed to show the actuating device and Vlock for thefriction members in elevation; and Fig. 6 is sectional view showing the actuatingA device and lock of Fig. `5 in plan. i

In these drawings I have illustrated one embodiment of the invention and have shown the sameV as applied to a lifting jack of a type shown in Patent No. 1,344,117, granted June Q2,

but vit will be understood that this particular type of ack has been chosen for the purpose of illustration only, that the controlling mechanism may be applied to jacks of vari- A ous kinds and may take various forms without departing from the spirit of the invention. p i

The jack as lieie shown comprises a base 1 having a hollow standard 2 extending upwardly therefrom and provided at ,its up-` per end with a nut 3 in which isthreaded av screw 4 constituting the lifting elementof the ack. Rig-idly secured to the screw above the nut is a beveled gear 5 on which is sup ported the load engaging cap 6, a ball bean beveled gear 5.

1920 to Ripsch, Dawley and Derby,

ing 7 being preferably.interposed between the capand the gear. Rigidly secured to and depending from the load engaging cap 6 is a housing S which embraces the standard y able bearings formed in the inner wall 12 of the supplemental housing and in 4the partition 11 is a shaft 13 which extends into the main housing and has mounted on its' inner end a beveled gear 14 which meshes with the The outer end of the shaft extends beyond the outer wallof the supplemei'ital housing and has rigidly secured thereto a ratchet wheel 16 with which coope'rates' a -pawl 17 carried by a` lever socket ,18 pivotally mounted on the end of the shaft. The manipulation of this lever will rotate the shaft 13 in the direction to impart lifting movement to the lifting element.

The downward movement of the lifting element is normally prevented by suitable cont-rolling devicesl of such a` character'that they will not interfere with the elevation of the liftingeleinentzbut will normally nreveiit the downward movement thereof. Y his cont-rolliiig device coii'iprisesineans, however, for releasing the load to permit it to move downwardly under its own weight, the lift- Rigidly secured to one side of thek into two compartments. Journaled in suiting screw being of such a pitch that-,it will run downward yund-er the weight of the nor.-

Amal load. In the present embodiment of the invention the controlling mechanism comprises a worm gear19 rotatably mounted on the shaft 13 and meshing with a worm 20 secured to a shaftQ()a which extends traiisversely to the shaft The worm 2O is connectedat its rear end with a brake shaft 21 to which is rigidly secured a` brake meinber or drum 22. The connection between the worm and the brake shaft may be of any suitable character and as here shown a,. worm gear 120 is connected with the worm 2() A and meshes with a worm 121 on the brakeshaft The worm gear 19 being loosely mounted on the shaft 13 will notdinterfere With the rotation of that shaft during the elevation lll shaft when the latter is rotated in a reverse direction by the downward movement of the lifting element.. In the present construction. this clutch comprises a ratchet wheel 23 rigidly secured to the shaft 13 adjacent to the worm gear 19, this gear being here :ihown as provided with a. recess in its outer face so that the periphery thereof partially overhangs the ratchet wheel. kRigidly secured to the worm gear, partially within the recess therein, is a` pawl carrier or frame which, as here shown, comprises an inner annular f ame member or plate 24 which is rigidly secured to the web of the worm gear by means of a series of studs 25 and 2G, cach 'ot' which is provided with a. collar 27 seated in a recessin the outer face ofthe annular plate 2l and has its inner end projecting through the web of the worm gear and upset or riveted to rigidly secure the same thereto. Each of the studs 25 and 2G project beyond the Vouter faceof the annalar plate 24 and these studs form supports, respectively, for pawls'and springs. The inner member 24 of the pawl carrier has rigidly secured thereto and preferably formed integral therewith a series of abut ments 28 which extend across the ratchet wheel and to the outer ends of which the outer member 29 ofthe pawl carrier is secured, this outer member also being in the form of an annularl plate and being here shown as secured to the abutments by screws $30. The several ahutments 28 are spaced short distances in the rear of the respective studs 26 and each abutment is provided in that edge adjacent to the corresponding stud with a curved recess 31,' the surface of which conforms substantially with the are of a circle described about the axis of the stud. Mounted on each stud 26 is a pawl 32 havingl its ends shaped to lit within :he recess 31 of the adjacent abutment. The pawl is loosely mounted on the stud, the opening therethrough being of greater diameter than the diameter of the stud, so that the thrust on the pawl will be against the abutment and not` against the ustud. The studs 25 are arranged in the rear of the respective abutmentsQS and between the same and the free endg of the succeeding pawls. Coiled about each of these studs 2,"3 is a spring having an end portion l projecting from one side thereof and engaging the rear edge of the'adjacent abutment 28. The other end portion'l of the spring projects 'rearwardly and engages the free end of the succeeding pawl to press the,

same against the ratchet wheel. Each spring is coiled loosely about its stud 2o so that when placed under tension the coils may contract, thus permitting the veasv compression of the spring and avoiding the loealizing of the strains. Such a. construction permits the use of a strong spring but provides the same with a large degree of resiliency and a corresponding ease of operation. Further, the arrangement enables the force to be applied to the pawl near the free end thereof where it will be most etiectively utilized. Y

It will be apparent, therefore, that when the lifting element moves downward the clutch will connect the worin gear with the shaft 13 and cause this worm gear to rotate. The pitch of the teeth on the worm gear and worm 20 is such that the worin gear will drive the worm and movement will he transmitted from the worm shaft 2l to the brake member or drum 22. Cooperating with this brake member is a friction device which may be caused to engage the brake member to prevent or retard its rotation. Preferably this friction device is' provided with parts which are movable toward and from one another to control the action of the friction device on the brake member. These movable parts may be arranged in any suit` able relation to the friction device and, as here shown, are so arranged that their movemont one toward the other will canse the friction device to operatively engage the brake member. The movable parts are acted upon by a yieldable device which tends normally to so move the parts as to cause the friction device to grip the brake member but which may be manually retracted to relieve the gripping action of the friction device to the desired extent. Associated with this yieldable device are means for positively holding the friction device in grippng engagement with the brake member and to thus lock the brake member against movement.

The controlling devices for the friction device may take various formsl and may he arranged in various positions with relation one to the other. In that form of inechanism here illustrated the friction device consists of a single annular member or split ring 5l, the split side of which is arranged at the forward side. of the brake drum and is provided with forwardly extending lugs the outer edges of which are preferably tapered. The friction member is provided at its rear side with a recess to receive a fixed stud or pin 5G which centers the same with relation to the brake member. Slidably mounted within the housing 10 is a slide block 57 which is here shown as mount-4 ed in a guideway 58 rigidly secured to the partition 11 and which has in its rear end a tapered recess 59 to receive the forward ends of the tapered parts or lugs 55 of the friction device. A spring acts on this slide block to vpress the same rearwardly and cause the friction device to normally grip the brake member. Preferably the slide block is provided with a forwardly extending stem or shank 6() about which is coiled lll) lso

a spring 61 which is coniinedgbetween the side wall of the housing and the slide block and tends to nieve that block rearwardly. The stem 60 has a reduced portion which extends through an opening in the side wall of the housing and this reduced portion is here shown as a separate rod 62 which is screw threaded into the stem G0 and providedon itsgouter end with a' knob G3 by means of which the stem and slide block Vmay be drawn outwardly against the action tive engagement with the brake drum.

While I have shown and describedl certain embodiments of'my invention I wish it to be understood that Ido not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art. r

Having now fully described my invention, whatV I claim as new and desire to secure by Letters Patent, is: i 1. In a lifting jack, the combination with a lifting element, means for actuating the same to lift the load, a rotatable brake member, means foi' causing `said brake'member to be rotated by the downward movement of said lifting element7 and a friction device cooperating with said brake member to control tlie downward movement of said lifting element, of controlling mechanism comprising separately.operable means to normallyA control the action of said friction device and to positively retain said friction device 1n contact with said brake member.

In a lifting jack, the combination with e a lifting element, means for actuatingthe same to lift the load, a rotatable brakemciubei', means for causing said brake member to be rotat'd by the downward movement ofr said lif, ng element.` `and a friction device cooperating with saidV brake member to control the downward movement of saidlifting` element, of controlling mechanism comprising manually operated means to normally control the action of said friction device,.and a screw threaded member to lockvsaidv fric tion device in contact with said brake member. i

3. In a lifting jack, the combination with a lifting element, `means foractuatingthe same to lift the load,` a rotatable brake member, means for causing said -brake member to be rotatedV by` the downward movementY of said lifting element, and a friction device cooperating with said brake -member and comprising parts movable toward and from cach other to control the contact between said friction device and said brake member, of a'. single vlocking member movable into engage'ment` with both of said parts to lock said friction device in contact with said brake member.

4. In a lifting jack, the combination with a lifting elenfieiit, means for actuating the same to lift the load, a rotatable brake meinber.l means foricaiising said brake member to'be rotated by the downward movement of said lifting element, and a friction device cooperating with said brake member and Ycomprising parts movable' toward and from each other to control the contact between said friction device and said brake member, of a single locking member movableinto wedging` engagement with said parts to lock said friction device in contact with said brake member.

Y In a lifting ack, the combination with a lifting element, `means for actuating the same to lift the load, a rotatable brake. member, means for causing said brake-member to be rotated by the downward movement of said liftingeleinent, and a friction device cooperating with said brake'member and comprising parts movable toward and from each other to control the Contact between said friction device and saidbrake member, of controlling mechanism comprisingl means to normally controlthe action of said friction device, and a screwY acting on said parts to lock said friction device in contact with said bra-ke member.

6. In a lifting jack,-th'e combination with a lifting element7 means for actuating the saine to lift the load,a rotatable brake member, means for causing said brake inembeito be rotated by the downward movement of said lifting element, and a friction device cooperating with said brake member and comprising parts movable toward and from each other to control 'the contact between said friction devicean'd said brake meinber,

said parts having contact surfaces converging one toward the other, of a locking inembc'r to engage said converging surfaces. anzi lli) means for actuating saidlocking` member I i and holding the saine positively in chagement with said surfaces. Y

l7. vIn a lifting jack, the combi nation with alifting element,r means for actuating the same to lift the load, a ro atable brake ineinber7 means for causing said b ke member tcbeV rotated by the downward movement of said lifting' element, and a friction device cooperating with `said brake member to control the downward movement of said .lifting element. of a mechanism to control the action of said friction device on said brake member comprising ay spring to hold the fricn4 tion device normally 4in contact with -said brake member, manually operated meansto release said brake member, and means other than said spring to retain said friction device in contact with said brake member.

S. In a lifting,lr jack, the combination with a lifting element. means for actuating the same, tovlift the load` a rotatable brake member.` means for causing said brake member to be rotated by the downward movement of said lifting element, a friction device cooperatingT with said brake member to control the downward movement of said lift-ing ele` ment, a spring acting on said friction device to hold the same normally in contact with said brake member, and manually operated means for releasing said friction device from the action of said spring. of a locking' devic to positively retain said friction device in contact with .said brake member.

9. in a lifting jack, the combination with a lifting element, means for actuating the same to lift the load, a rotatable brake member, means for causing said brake member| to be rotated by the downward movement of said lifting element, and a friction device cooperating with said brake member and comprising parts movable toward and from each other to control the contact between said friction device and said brake member, of a spring acting on said friction device to hold the same normally in contact with said brake member a. manually operated device to release said friction device from the action of said spring, and a screw operated device to engage said parts and retain said friction device. in contact with said brake member.

10. In a lifting jack, the combination with a lifting clement, means for actuating the same to lift the load, a. rotatable brake member, means` for causing said brake member to be rotated by the downward movement of said lifting element, a friction device comprising contaft membersr to engage said brake. member. and pivoted arms connected with said contact. members to move the same into and out of engagement with said bral-:e member. of a spring actingr on said arms to hold said contact members normally in en- `sagement willi said brake member. means to release said arms from the action of said spring.r a device to engage said arms and positively retain said contact members in engagement with said brake member.

1 l. ,in a lifting' ack, the combination with ay liftingT element.y means for actuating the same to lift the load. a rotatable brake member, means for causing said brake member to be rotated by the downward movement of said lifting` element, and a friction device cooperating with said brake member and comprising parts movable toward and from each other to control the contact between said friction device and said brake member,

a slide block having a recess provided withA converging walls toengage said parts, and a spring acting?r on said slide block to move the same toward said friction device.

12. In a lifting jack, the combination with a lifting element, means for actuating the same to lift the load, a rotatable brake member, means for causingr said brake member to be rotated by the downward movement of said lifting element, and a friction device cooperating with said brake member and comprising parts movable toward and from each other to control the contact between said friction device and said brake member, of a slide block havingr a recess provided with converging walls to engage said parts, a spring1r acting on said slide block to move the same toward said friction device, and a screw acting on said slide block to hold the same positively in engagement with said parts of said friction device.

13, In a lifting jack, the combination with a liftingr element, means for actuating the rame to lift the load, a rotatable brake member. means for causing said brake member to be rotated by the downward movement of said lifting' element', and a. friction device having parts movable toward and from each other to control said brake member, of a slide block having a tapered recess in one end thereof to receive said parts of said fri c tion device, a stem for said slide block, a spring;r acting on said slide block to move the same into engagement with said parts of said friction device. means for rctracting said slide block against the action of said spring, and a screw threaded plunger movable into a position toengag/.fe said stem and hold said slide block in engagement with said parts of said friction device.

14. In a mechanism of the character dcscribed, the combination with a rotatable brake member, and a friction device to cooperate with said brake member, of a spring actingon Said friction device to hold the same normally in engagement with said brake member. and a screw actuated member to positively retain said friction device in engagement with said brake member.

15. in a mechanism of the character described, the combination with a rotatable brake member.y and a. friction device to cooperate with said brake member, of controlline' mechanism comprising manually controlled means to normally control thevaction of said friction device, and means operable independently of said manually controlled means to positively retain said friction device 1n engagement with said brake member.

16. In a mechanism of the character described. tbe combination with a rotatable brake member, and a friction device cooperating with said brake member and comprisingparts movable toward and from each other to control the contact between said friction device and said brake member, of

lll)

controlling mechanism acting on ysaid parts of said friction device and comprising means to normally control the action of said friction device and other means to lockfsaid friction device. in contact with said brake member. t

17. In a mechanism of the character described, the combination with a rotatable brake member, and a friction device cooperating with said brake member and comprising parts movable toward and from each other to control the contact between said friction device and said brake member, of controlling mechanism comprising a device movable into wedging engagement with said parts, means to lck said device in engagement with said parts, andmeans operable independently of the last mentioned means to normally control the action of said friction device.

18. In a mechanism of the character described, the combination with a rotatable brake member and a friction device cooperating with said brake member and compris-` ing parts movable toward and from each other to control the contact between said friction device and said vbrake member, said parts having contact surfaces converging one toward the other, of a locking member to engage said converging surfaces, and means for actuating said locking member and for holding the same in positive engagement with said surfaces.`

19. In a mechanism of the character described, the combination with a `rotatable brake member and a friction device cooperating with said brake member and comprising parts movable toward and from each other to control the contact between said friction device and said brake member, of a spring actuated device to hold said friction device normally in contact with said brake member, a manually operated device to move said spring actuated device against the action of its spring to release said brake member, and screw operated means to retain saidfriction device in contact with said brake member. Y

20. In a mechanism of the character described, the combination with a rotatable brake member and a friction device cooperating withsaid brake member and comprising parts movable toward and from each other to control the contact between said friction device and said brake member, of a controlling device acting on said movable parts of said friction device to cause the latter to engage said brake member, a spring acting on said controlling device to cause said friction device to be held normally in engagement with said brake member, and other means acting on said controlling device to positively lock said friction device in engagement with said brake member.

21. In a mechanism of the character described, the combination with a rotatable brake member and a friction device cooperating with said brake member and comprising parts movable toward and from each other to control the contact between said friction device and said brake member. of a slidable member having aA recess to receive said l'parts of said friction device and engage thesame with a wedging action, and a spring actingon said slidable member tocause the same to move said parts one toward the other.

22. In a mechanism of the character described, the combination with a rotatable brake member and a friction device cooperating with said brake member and comprising parts movable toward and from `each other to control the contact between said friction device and said brake member, of a slidable member having a recess to receive said parts of said friction device and engage the same with a wedging action, a spring acting on said slidable member to cause the same to move said parts one toward the other, and a screw actuated device acting on said slidable member to cause the same to positively hold said parts against` movement relatively one to the other.

23. In a mechanism of the character described, the combination with a rotatable brake member and a friction device cooperating with said brake member and comprising parts movable toward and from each other to control the contactfbetween said friction device and'said brake member, of a slide block having a tapered recess in one end thereof `to receive said parts `of said friction device, a stem for said slide block, a spring acting on said slide block to move the same into engagement with said parts of said friction device, means for retracting said slide block against the action of said spring, and a screw threaded plunger movable into a position to engage` said stem and hold said slide block Vin engagement with said parts of said friction device.

In testimony whereof, I afiix my signature hereto. a

JAMES C. DAVLEY.