US1334488A - Lifting-jack - Google Patents

Description

F. L. GORMLEY.

LIFTING JACK.

APPLICATION FILED MAR. 24' I919.-

Patented Mar. 23, 1920.

2 SHEETS-SHEET I.

Inventor: FrankL.Gorm1,e

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LIFTING JACK. APPLICATION FILED MAR. 24, m9. 'Jlfi3%%88@ Patented Mar. 23, 1920.

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Irwenlor: Frank L. Gormley,

UNITED STATES PATENT OFFICE.

FRANK L. GORMLEY, OF CBEOOKLINE, MASSACHUSETTS, ASSIGNQR TO A. 0. NORTON, INC., 01 BOSTON, MASSACHUSETTS, A. CORPORATION OF MAINE.

LIFTING-JACK.

Specification of Letters Patent.

Patented Mar. 23, 1920.

Application filed March 24, 1919. Serial No. 284,842.

To all whom it may concern:

Be it known that I, FRANK L. GoRMnnr, a citizen of the United States of America, and a resident of Brookline, in the county of Norfolk and Commonwealth-of Massachusetts, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification.

This invention relates to lifting jacks and particularly to devices of this character de signed for heavy work, the object of the present invention being the provision of means whereby the lowering of the movable member under great loads may be either automatically or manually controlled.

The invention is an improvement upon Letters Patent #1287366 granted to me Dec. 17, 1918.

The present invention consists in provid ing the jack with a revolulole shaft having secured thereon a brake disk adapted to coact with a manually operated brake member, said shaft also being surrounded by an automatic braking device operable under centrifugal action to impinge uponthe cylindrical wall ofa non-revoluble chamber within which said automatic governor operates.

The invention further consists of certain novel features of construction and arrangement of parts which will be more fully understood by reference to the description of the drawings and t the claims to behereinafter given.

F or the purpose of illustrating the invention, one preferred form thereof is illustrated in the drawings, this form having been found to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which the invention consists can be variously arranged and organized and that the invention is not limited to the precise arrangement and organization of these instrumentalities as herein shown and described, except as required by the scope of the appended claims.

Of the drawings:

Figure 1 represents a horizontal section of a lifting jack embodying the features of the present invention, the cutting plane being on line 1, 1 on Fig. 2.

Fig. 2 represents a vertical section of the same on line 2, 2 on Fig. 1.

Fig. 3 represents a vertical section on line 3, 3 on Fig. 2, drawn to an enlarged scale.

like parts throughout the several figures of j the drawings.

In the drawings, represents a suitable base supporting a stationary standard 11, over the outer periphery .of which is fitted a movablesleeve 12, to the upper end of which is threaded a cap 13.

In the upper end of the standard 11 is mounted a nut 14 to which is threaded a lifting screw 15 having splined to itsupper reduced end a bevel gear 16 with which meshes a bevel gear 17 formed upon or secured to a revoluble shaft or spindle 18, the outer end of which is provided with a suitable operating mechanism 19 of any wellknown construction.

Between the upper face of the bevel gear 16 and the inner face of the cap 13 are two annular plates 20, 21, between which are interposed a plurality of anti-friction members 22.

The movable member 12 is provided on one sidewith a flanged projection 24 having a removable plate 25 secured thereto by bolts 26.

The plate 25 is provided with a bearing 27 for the spindle 18, and keyed to said spindle 18 between the inner end of said bearing 27 and .the rear face of the bevel gear 17, is a worm gear 28 rotatable in either direction With the bevel gear 17.

The worm gear 28 meshes with a worm 29 formed upon or secured to a shaft 30 revolubly mounted in cars 31, 32 projecting inwardly from the plate 25.

On one end of the shaft 30 and adjacent to the car 32, are two collars 33, 3 1 between which are interposed a plurality of antifriction members 35, said collars 33, 34: being retained together by a ring 36 secured to the collar 33 and having an annular flange 37 extending over the outer face of the collar 34:. The collars 33, 3a with the anti-friction members form a thrust bearing for the shaft 30 on which the said thrust bearing is retained by a nut 38 threaded to the reduced end 39 of said shaft.

Loosely mounted 011 the opposite end of the shaft 30 is a spur gear 4:0 having a tapered annular flange 41 with which coaicts V a disk 42 keyed to the'shaft 80 and having a coneashapedperiphery adapted to contact with the tapered flange 41 of the gear 40.

The disk 42 is retained upon the reduced end 43 of the shaft 30 by means of the nut 44 threaded to said reduced end. When the movable member 12 is being raised, the worm gear will be rotated in the direction .of the arrow at on'Figj 8 of the drawings and the disk 42 will be separated from the flange 41 and no rotation will beimparted to the spur gear 40.

.lVhema load is on the cap 13 tending to lower the member 12, the tendency would be to rotate the worm gear 28 in a direction opposite tothat indicated by the arrow at and the worm shaft 30 would be moved endwiSe, toward the right of Fig. 3, until the cone-shaped,periphery of the disk 42 has been brought into firm contact with the ta peredflange 41 on the gear40.

It; isv obvious that under these conditions any iro tary'movement imparted to the shaft keyed a brake disk 49.

The brake disk 49 is provided on one face with ears 50 to which are pivoted the links 51,-said linksfhaving pivoted to their opposite ends at 52, other .links 58, the opposite ends of which are pivoted to a collar 54 slidable uponthe rcduced'end 55 of the shaft 46.

" 1 This reduced end 55 of the shaft 46 is mounted in a bearing 56 formed in a lug 57 formed uponthe'cover plate 25.

The collar 54 is preferably keyed to the reduced end 55 of shaft 46 as indicated in the drawings. V V V The cover plate 25 is also provided with an inward projection 58"l1avi'ng a cylindrilcal chamber 5.9 therein: g

;To each pivot member 52 is pivoted a friction pad 60 adapted to coact with the wall of the chamber 59 when the shaft 46 rotates at a predetermined speed thereby preventing the load from being lowered too rapidly.

V 7 light helicalv spring 61 between the brake disk 49 and collar 54 normally retains the collar in contact with the lug 57 with the friction pads 60 free from contactwith the wall of the chamber 59. e

Any excessivespeed ofthe shaft 46 will tend'by-centrifugal action to move the friction pads 60 outwardly intocontact with the wall of said chamber 59 and by the frictional contact'of these pads 60 with said wall, the H g speed of the shaft 46 will be retarded in an obvious manner.

The cover plate 25 is provided with outwardly extending ears 62 to which is pivoted a brake member 63, one arm of which is curved to contact with the periphery of the brake disk 49 while the other arm 64 serves as a means for manually separating said brake member 63 from the disk 49 when it is desired to lower the load.

The brakemember 63 is normally held in contact with the periphery of the disk 49 by means of the spring 65 positioned in a socket 66 formed in the outwardly extending boss 67 of the cover plate 25.

The spring 65 acts upon a shoulder 68 formed on the outer end of the brake member 63 as indicated in Fig. of the drawings.

As long as the brake member 63 is in contact with the disk 49, the worm 29 will be prevented from rotating and as a consequence, there can be no downward movement of the member 12.

The rapidity of the lowering of the member 12 will be automatically controlled by the governor friction pads 60.

The pitch of the threads of the worm 29 is such that said worm may be rotated by the rotation of the worm gear 28.

In the operation of the jack, the worm gear 28 is revolved in the direction of the arrow a when raising the load and at the initial movement of said gear 28, it will through the slight end movement imparted to the worm 29, disengage the members 41, 42 so that there will be no brake devices or friction to retard the rotation of said gear.

lVhen, under the load, the gear 28 begins to rotate in the opposite direction, the worm 29 will be moved in the opposite direction, the worm 29 will be moved ondwise until the members 41, 42 are engaged and then rotary movement will be imparted from the shaft to the short shaft 46 through the gears 40, 45. At this time the brake member 63 will be disengaged from the brake disk 49, said disengagement having been effected by the pressure of the hand of the operator upon the arm 64. a

When, on account of an excessive load upon the cap 13, the member 12 moves downwardlytoo rapidly, the greater speed of the shaft 46 will cause the friction pads 60 to impinge upon the wall of the chamber 59 and thereby automatically arrest the too rapid downward movement of the member 12.

When it is desired to arrest all further downward movement of the member 12, pressure is removed from the arm 64 and the spring 65 will force the brake member 63 into frictional contact with the periphery of the disk 49 and further rotation of shaft 46 will be prevented.

This makes a very simple mechanism for controlling the lowering of the jack and it is believed that its operation and the many advantages of the invention will be readily understood without further description.

Having thus described my invention I claim: a

1. In a lifting jack, the combination of a revoluble operating shaft; a worm gear keyed to said operating shaft; a worm meshing with and adapted to be rotated by said worm gear and having end movement; a gear loosely mounted on the worm shaft; a member secured to said shaft adapted to be moved with said shaft into driving engagement with said gear during the lowering operation; a revoluble shaft parallel to said worm shaft; a pinion thereon meshing with said gear; a fixed cylindrical wall surrounding said parallel shaft; toggle arms revoluble with said parallel shaft; and friction pads secured to said toggle arms and adapted by centrifugal action to be forced into engagement with said cylindrical Wall.

2. In a lifting jack, the combination of revoluble operating shaft a worm gear keyed to said operating shaft; a worm meshing with and adapted to be rotated by said worm gear and having end movement; a gear loosely mounted on the WOl'HlaShaft; a member secured to said shaft adapted to be moved with said shaft into driving engagement with said gear during the lowering operation; a revoluble shaft parallel to said worm shaft; a pinion thereon meshing With said gear; a fixed cylindrical Wall surrounding said parallel shaft; toggle arms revoluble with said parallel shaft; a collar slidable on said shaft to which one end of said toggle arms are pivoted; and friction pads secured to said toggle arms and adapted by centrifugal action to be forced into engagement with said cylindrical wall.

3. In a lifting j ack, the combination of a revoluble operating shaft; a worm gear keyed to said operating shaft; a worm meshing with and adapted to be rotated by said worm gear and having end movement; a gear loosely mounted on the worm shaft; a member secured to said shaft adapted to be moved with said shaft into driving engagement with said gear during the lowering operation; a revoluble shaft parallel to said worm shaft; a pinion thereon meshing with said gear; a fixed cylindrical wall surrounding said parallel shaft; toggle arms revoluble with said parallel shaft; a collar slidable on said shaft to which one end of said toggle arms are pivoted; a light spring surrounding said parallel shaft and tending to straigthen said toggle arms; and friction pads secured to said toggle arms and adapted b centrifugal action to be forced into engagement with said cylindrical wall.

Signed 'by me at 4: Post Oflice Square, Boston, Mass, this 21st day of March, 1919.

FRANKL. GORMLEY. lVitnesses:

WALTER E. LOMBARD, NATHAN G. LOMBARD.

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