US1385489A - Lifting-jack - Google Patents

Description

A. NEAL.

LIFTING JACK. APPLICATION FILED mm: 14, 1920.

2 SHEETS-SHEET I.

ATTORA Patented July 26, 1921.

A. NEAL.

LIFTING JACK.

APPLICATION FILED JUNE 14, I920.

Patented July 26, 1921.

2 SHEETS-SHEET 2.

TORNEX PATENT OFFICE...

ALBERT NEAL, or KOKOMO, nnIANA.

LIF'IING JACK.

T 0 all whom it may concern:

Be it known that I, ALBERT NEAL, a citi zen of thefUnited States, residing at Kokomo, in the county of Howard and State of Indiana, have invented certainv new and useful Improvements in Lifting-Jacks, of which the following is a specification.

This invention relates to that class of lifting jacks shown in my pending applications Nos. 256,496 and 286,021; and the principal object of the present invention is to provide a lifting jack which is not restricted to the accomplishment of the limited objects sought in my prior applications, but is directed to a more ingenious organization of parts whereby all the objects which are attained in my previous applications can be attained in the present structure.

I accomplish the above objects, and such others as may appear. from a perusal of the following description and claims, bymeans of the construction illustrated inthe accompanying drc wings, forming a part hereof, in which Figure 1 illustrates a side elevation of my improved lifting jack, showing the parts in their initial position for elevating the lifting-bar. Fig. 2 illustrates the position of the parts. atthe end of their initial movement in elevating the liftingebar. Fig. 3 illustrates the initial position of the parts in lowering the lifting-bar. Fig. 4: illustrates the position of the partsZ'at-the end of their initial movement in lowering the lifting-bar. Fig. 5 illustrates the position the parts assume in dropping. the lifting-barat one operation. Fig. 6 is an edge view, on the line 6-6. in Fig. 4. Fig. .7 is a vertical sectional view, on the line 7-7 in" Fig. ,5.

Fig. 8 is a cross section, on the line 8-8 in Figs. a-and 6. Fig. 9. is .aview partly in section and partly in 'elevat-iom on the horizontal plane .99 in Fig.6. Y

'Referring to the drawings, 15 represents the standard or frame having a base 16,- and said framexis also-provided with'a rlongitudinal channel .17 which is adapted toreceive and form a guide for a movable lifting bar 18, thelatterxbeing provided inone edge with teeth 19. "Channel-17 is formed by the raised end walls 20 and 21.0f framev 1-5, and wall 21 is of less height. than wall 20 so as to provide. working clearance to.- p-ermlt the engagement of .the. pawls with the actuator Application filed June 14,

, Specification of Iletters Patent; Patented July 26', 1921.

1920. Serial No. 388,764.

able guide-bar 23 (see Fig. 8) one flange of which rests against the exposed face of lifting-bar 18 and the remaining flange 25 riding against the external face of housing 15. Guide-bar 23 is induced to travel in unison with lifting-bar 18 through the medium of an integral transverse rib 26, on bar 18, engaging an overhanging lip 27 forming apart of guide-bar 23, as clearly shown in Fig. 3. To equalize the strain on both sides of'lifting-bar '18 the latter is provided on its edge opposite the edge carrying the transverse rib 26 with a similar rib 28 which contacts the under edge of a loop 29 formed integrally with the guide-bar 23 and which passes. across the exposed face of lifting .bar 18. By means of the channel formation'of the guide-bar 23, which permits it to extend across the exposed face of lifting-bar 18 and a part of the external face of frame 15, a part of frame 15 is within the embrace of the channel guidebar 23, whereby the guide-bar 23 overlaps 7 frame 15 and lifting-bar 18 and not only serves to maintain the parts. in alinement when the lifting-bar 18 is extended, but prevents lateral displacement of the lifting-bar from'the frame 15 without the use of ribs and grooves, as appear in my earlier applications, 'andwhich are notonly difiicult to cast but increase the cost of manufacture.

Lifting-bar 18 may be extended or retractediaccording to the desire of the operator, by means of a load supporting pawl 30 and abar actuating pawl 31 which'are alternately oscillated in opposite directions through the location of their points of attachments relatively to pivot 32 of the actu- I nut 33 so that displacement of lever 33 is prevented. W'ith the pawls occupying the positions indicated in Fig. 1 it will. be seen that pawl 30 is engaged with lifting-bar 18 and is supporting the load, whereas the'free end of pawl 31 is disengaged from saidteeth.

When the actuator lever 33 is elevated to ward the position indicated in Fig. 2 the.

and carry lifting-bar 18 with it. During the above movement of pawl 31 and bar 18 theload is removed from pawl 30' and the latter moves downwardly and reengages one of the teeth. from lower down in bar 18 by the time bar 33 reaches the limit of its upward travel, when pawls 30 and 31 will be occupying the positions indicated in Fig. 2. The upwardmovement of lever. 33-is arrested by theengagement of the edge 34 of the aperture in the oval shaped ring 35, which is a part of lever 33, coming into contact with a fixed post 36which is mounted. on the ad- }:Jicent' face of enlargement 22 of frame- 15.

uring. the upward movement of bar 33 the weight of cam 40 is sustained by pawl 31 and serves to hold and preventdisengagement of the free end of pawl 31 from bar 18. Cam 40 varies the movements of the pawls, depending upon the position the cam occupies on its pivot, and is one of the predominating elements in the present device, as the following description discloses. Thus, in examining" Fig. 1, it will be observed that the weighted portion 41 of cam. 40 is on the side of its pivot 43 to cause the cam to rest heavily upon a pin 44 carried by pawl 30' and thereby prevent, at this time,the accidental displacement of said pawl. from teeth '19. When, however, lever 33' isbein elevated into the position indicated in i'g. 2, the weight of cam 40 is removed from pawl 30 and is shifted to pin 45 of pawl 31, so'that pawl 30 is free to disengage itself from teeth 19 and move downwardly along lifting-bar 18 as the upward movement of lever 33continues.

The heretofore described movements'of the parts impart a movement for a progressive extension of'lifting-bar 18, and while cam 40 occupies-the position indicated in Figs. 1 and2l'ifting-bar 18 cannot be retracted as cam 40 must be moved on its pivot to assume the position indicated in Fig. '4 to-permit the progressive lowering of lifting-bar 18. The reason for this is that when the position of cam 40 is shifted on it's pivot its irregularly shaped surfaces-will assume new angles and thereby change the action of pawls 30-and 31. The movement of cam 40 on its pivot from the position indicated in Fig. 1 to thatindicated in Fig. 3 is determined by means of the fixed post 36 coming into contact with the inner edge 42 of the irregularly shaped a erture in cam 40, as clearly indicated in Hg. 4.

When it is desired to progressively lower lifting-bar 18, the first portion of the upward movement of lever 33, in View of point of connection between pawl 31 and lever 33 relatively topivot 32 of said lever 33, would normally move the free end of pawl 31 into engagement with the notch inba'r 18 lying immediately advance of said pawl (Fig. 1) but the action ofcam 40 at this timepre ventsthefree end of said pawl from entering that particular notch, for the reason that pawl 31 should engage lifting-bar 18 higher through the contact of edge 42 of the irregularly shaped aperture in cam 40 with pin 45 of pawl 31, a corresponding movement isimparted to the free end of pawl 31, or from the position'indicated by full lines to the position indicated by dotted lines in Fig. 4. As the upward movement oflever 33 continues the convex-shaped extension I 50 of cam 40 is brought into contact with the undersideof pin 44 on the now downwardly moving pawl 30, which. arrests further oscillatory movement of cam 40' on itsfpivot. The weight of cam now being shiftedfrom pawl 31 to pawl 30, through the breaking of the contact between edge. 42" and pin 45- pawl 31 is released and. is free to move upwardly and enters a notch higher upv in bar 18 by the time lever 33 reaches the limits of its upward. travel. The release of: pawl 31 however has been delayedlong enough and. the pawlhas'moved upwardly far enou h above its: former position to enable its free end toenter a notch higher up in bar 18 than A p it would have engaged if itsfmovement previously had not been restrained by cam 40. H

During the latter part of the upward move ment. of level-'33 producing the above. results.

teeth 19., leaving thepawls in the positions indicated in Fig. 2, wheni lever 33- reaches the limits of its upward'travel; Pawl. 3O isnow held by the hook formed by the recess 51 in extension50 engaging pin 44. In this posi- 1 tion with the'first downward movement of lever 33 the free end of pawl 30 is: moved away from bar 18 until its outer face'contacts the adjacent face of the now downwardly moving pawl 31 whereby the weight of cam 40 is removed: from pawl- 30 and ef-.

fects the disengagement of pin44 from recess 51 and directs the free end of pawl 30 back into engagement with teeth 19 under the continued downward movement of lever 33, and when lever 33 reaches the limits of its downward travel the pawls will occupy the positions indicated in Fig. 4:. This last described movement is repeated each time lever 33 is lowered, with cam occupying the position indicated in Fig. 4.

The description so far relates to the movements of progressively elevating and lowering lifting-bar l8, and the manner in which the bar when elevated may be dropped at a single operation, and which is desirable in many cases, will now be described.

When the present jack is employed for raising an automobile to enable a tire to be changed there is no necessity for a progressive lowering movement of the load, for the reason that an inflated pneumatic tire acts as a cushion in absorbing shocks and thereby reduces the liability of injury to the mo tor car. When lifting-bar 18 is in an extended position andit is desired to drop the bar at one operation, the operator moves cam l0 approximately midway of its range of oscillatory travel (see the comparative position of-cam 40 in Fig. 5 relatively to the positions shown in Figs. 1 and 4) whereby the restraint of cam 40 is entirely removed from pawl 31 which allows the latter to be disengaged from teeth 19 through the lowering movement of lever 33, and when said lever moves a suilicient distance the inner edge 42 of the aperture in the oval shaped ring 35 will engage and actuate pin M to disengage pawl 30 from teeth 19, thus leaving the lifting-bar l8 unsupported and tree to drop. 3

Having thus fully described my said invention, what I desire to secure by Letters Patent, is-

1. In a lifting jack, a channeled standard, a toothed lifting-bar moving in the channel of said standard, and a movable guide-bar having independent movement of the standard and adapted to extend across the edge and one side of the standard and the exposed side of the lifting-bar for maintaining the alinement of the associated parts.

2. In a lifting jack, a channeled standard, a toothed lifting-bar moving in the channel of said standard, a movable guide-bar having independent movement of the standard and adapted to embrace the lifting-bar and standard for maintaining the alinement of the associated parts, means for preventing independent movement between the guide-bar and the lifting-bar, and means for actuating the two bars longitudinally of the standard.

3. In a lifting jack, a channeled standard, a toothed lifting-bar moving in the channel in said standard, a guide-bar adapted to embrace the lifting-bar and standard for maintaining the al'inement of the associated parts, a bar sustaining pawl and a bar actuator pawl, a lever for mounting and for alternately actuating said pawls for the progressive extension of the bar, and a cam carried by the lever and having independent movement of the lever for effecting the complete disengagement of both pawls from the lifting-bar.

In witness whereof I have hereunto set my hand and seal at Indianapolis, Indiana, this 9th day of June, A. D. one thousand nine hundred and twenty.

ALBERT NEAL. [L. s.]

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