US821840A - Lifting-jack. - Google Patents

Description

PATENTED MAY 29, 1906. STORY & W. A. HALL LIFTING JACK.

APPLICATION FILED JAN. 2. 1906.

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UNITED STATES PATENT oFFIoE.

LlFTlNG-JACK.

Specification of Letters Patent.

Patented May 29, 1906.

Application filed January 2, 1906. Serial No. 294,172-

To all whom it may concern.-

.Be it known that we, WILLARD A. STORY and WILLIAM A. HALL, citizens of the United States of America, and residents of Chillicothe, in the county of Ross and State of Ohio, have jointly invented certain new and useful Improvements in Lifting Jacks, of which the following is a specification.

This invention relates to certain improvements in lifting-jacks, and more particularly in that class of screw-jacks which are capable of employment for lifting great weights and the object of the invention is to provide a device of this character of a simple and inexplensive nature and of a compact, strong, and curable structure which shall be capable of convenient use and wherein great lifting power is combined with a minimum liability of breakage.

The invention consists in certain novel featuresof the construction and combinations and arrangements of'the several parts of the improved liftingjack whereby certain important advantagesare attained and the device is rendered simpler, cheaper, and other wise better adapted and more convenient for use, all as will be hereinafter fully set forth.

The novel features of the invention will be carefully defined in the claims.

In the accompanying drawings, which serve to illustrate the invention, Figure 1 is a side elevation, partly in section, showing a lifting-jack constructed according to our in vention and in use beneatha load. Fig. 2 is an axial section taken vertically through the improved jack, the parts of thejack being,

however, adjusted to a position different Fig. 3 is a plan view showing the step or base plate of the jack detached. Fig. 1 is a plan view of the barrel or body portion and lifting-screw of the improved jack; and Fig. 5 is a side elevation similar to Fig. 1, but illustrating a modified construction of the improved jack which will be hereinafter referred to.

Referring first to Figs. 1 to 4, 1 represents the barrel or body portion of the improved lifting-jack, herein shown as formed from metal in elongated shape, with an octagonal cross-section, whereby flattened perpendicular faces 2 2 at angles toeach other are produced upon its sides, so as to adapt said barrel or body portion to be engaged by the forks or jaws of a. wrench or leverof a well-known kind, by means of which said barrel or body portion may be rotated by the operator in using the im roved jack.

The barre or body portion 1 is formed with an axial bore or hollow extended part way through it and opening at the upper endof said barrel or body portion, but being solid and closed at the lower end thereof. At said upper end of the barrel or body portion the said bore isformed with an internal screwthread, as shown at 3, and with said screwthreaded upper dpart of the bore is engaged the screw-threa ed shank or body 4 of the lifting-screw, the upper end of which hasa head or jaw 5, provided with a roughened surface, as shown in Fig. 4, for engagement beneath a load to be lifted, as indicated at a: in Fig. 1. i

The lower end of the lifting-screw is de-' I signed to pass down withinthe bore of the barrel or body portionl as the same is turned, and said bore is made of a length to receive the entire extent of the screw-threaded shank 3 of said lifting-screw, and in order to reduce friction between the parts to a minimum the lower end of the hollow in said barrel or body portion 1 is counterbored to a larger diameter, as shown at 6, so that there shall be no friction of the threaded shank of the screw upon the walls of the barrel or body portion at that point.

The closed lower end of the barrel or body portion is made tapered or conical, as seen at 7, and terminates in a solid rounded point 8, alined with the axis of said barrel and ofthe feed-screw engaged therewith, and said solid rounded point or extremity 8 of the barrel or body portion is designed for engagement in a step-like recess or depression 9, produced centrallyin the upper surface of a step or baseplate 10 and laterally enlarged, so that while the said pointed lower end 8 of the barrel is prevented from slipping laterally when rested in said depression or recess 9- the sides of the recess or depression are still out of contact with the surfaces of the tapered end of the barrel, whereby friction between the parts when the barrel or body portion is rotated is reduced as much as possible. y

The step or base-plate 10 is made with a while the head of the lifting-screw is engagedbeneath or against the load to be lifted ori moved, as indicated at as in Fig. 1. The bar rel'or body" portion 1 may then be turnedby means of the forked wrench or leverin a well+ known way, causing the threaded shank 4 of the feed-screw to pass out from the screwthreaded bore of said barrel orbody portion, so that the load is lifted or moved, as will be readily understood.

By our improved construction it will be seen that there is comparatively little liability of breakage of the parts ofthe jack, since the major portion of the stress in operation is imposed upon the barrel or bodyportion 1.

instead of on the lifting-screw, as is the case in jacks of ordinary construction. It will also be understood that great lifting poweris. attainable by the use of our improved jack,

since very little friction attends its 0' .eration and practically the entire strength 0 the operator is expended in power alone, which by the intermediation of-the screw is greatly augmented.- The improved jack is, further,

not limited'to use in a vertical position, but may be adjusted to a horizontal :OlylTlOllIlGd position without detracting from itsadvan tages and convenience. 1

Where desirable the step or base-plate 10 may be dispensed With, and when the jack is employed for lifting light loads, orfor trackwork, where it may be rested upon cross-ties or other sufficiently-solidsupport,- said plate may be dispensed with; but where there is any dis osition for the solid pointed lower end oft e body portion orbarrel to sinkinto;

its support, as in the case of lifting great loads orfworking uponsoft ground, said-:stepor base-plate is necessary for ,use. From the above description of. our improvements-it will be apparent that thelifting-jack con:

structed according to our invention is ofan extremely simple and inexpensive nature, and is capable of very. convenient use Without liability of breakage or undue loss of power throughfriction,and it will also-be ob-;

vious from the above description that the device is susceptible of considerable modifica: tion without material departure from the principles and spiritlof the invention, and for this reason we do not desire-tobe understood as limiting ourselves to the form; and arrangement.v Of-the severa parts recise as herein set forth in carrying out our invention in practice. For example, in certain cases the construction shown in Fig. 5 may be used with good results. In this form of the jack the body portion 1 has its bore extended entirely through it, its upper end having, for example, a right-hand screw-thread to receive and engage the corresponding screw-threadupon the stem of the main lifting-scr'ew 4, the head 5 of which supports the Weight as. The lower end of said bore in the barrel or bodyportion-l is provided with an opposite or left-hand screw-thread to receive the corresponding screw-thread. upon the stem 1 1 of an auxiliary or lower lifting-screw,

which has an integral base 12 torest upona supporting-surface.- When the barrel: is turned by means of a wrench or forked lever, the reverse screw-threads 'ofthe. barrel and main and auxiliary lifting-screws cause a rapid elevation or lowering of the load, so that much more rapid work may be :accom-.

plished than can be attained. by thejack' shown in the preceding views. This form of jack is, however, best:suited forluse: wheretheloads tobe shift-ed'are comparatively light, since increasedpower is requiredforthe increased speed attained by the employ-- ment of the reverse screw-threads.

Having. thus described our invention,what

weclairn, and desire to; secure-by Letters Patent,1s

1. A lifting-jack comprising a body'por tion of polygonal cross section-yand adapted to turn and provided with a screw-threaded" bore,- means, atone end of the body portion to engage, a support'and alifting-screw engaged in the threaded bore ofthe body portion and provided with a head to-engagea loadto beshift-ed.

\ 2. 'A lifting-jack comprising'a rotatory body portion provided with an axial bore,.the

latter being open at its upperlend only and provided with screw-threads part way down the body portion and'closed at the lower;0pposite. end of'said body portion, saidlower closed end of the-,bodyp'ortion, being tapered to a central bearing-tip or solid conical point alined with the axis of the body portion and a non-rotatory lifting-screw threaded for en gagement with the threaded portion of-the bore of the body portion and having a headto engage a load to beshifted;

3.- A lifting-jack-comp'ri sing a body portion adapted to turn and provided with an axial-bore open .at its upper endonly and provided with screw-threads .part' way down the. body portion from: said-upperend: :and closed at the lower, oppositeend of said body portion said lower closed end of the: body, portionbeingrtapered to asolid centraltip or. conical point alined with the axis ofthe body 4 Q portion, a base-plate engageable with a sup- Signed at Chillicothe, Ohio, this 29th day port and having a central recess or niche to of December, 1905.

receive the closed tapered tip or conical WILLARD STORY point of the body portion and a non-rotatory 5 lifting-screw threaded for engagement With WILLIAM HALL the threaded bore of the body portion and Witnesses: provided with a head to engage a load to be WALTER W. BOULGER, shifted. JAMES I. BOULGER.

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