US395928A - Lifting-jack - Google Patents

Description

NITE STATES ATENT Fries.

' AXEL A. STROM, OF AUSTIN, ILLINOIS.

LIFTING=JACK.

SPECIFICATION forming part of Letters Patent No. 395,928, dated January 8, 1889.

Application filed July 21, 1888- Serial No. 280,633- (No model.)

To (all whom it may concern.-

Be it known that I, AXEL A. STROM, a citizen of the United States, residing at Austin, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Lifting-Jacks, of which the following is a specification.

My invention relates to the class of liftingjacks provided with friction-clutch devices, one for performing the function of gripping the lifting-bar by actuating a lever conneeted with the clutch to raise the bar and the other that of supporting the lifting-bar in the position to which it has been raised. by the lifting-clutch. The principle of operation of the friction-clutch in the class of liftingjac (s to which my improvement relates is that of gripping the lifting-bar by binding it on opposite sides between two surfaces. A common device for producing the desired binding effect, and upon which particularly my present invention is designed to afford an improvement, is a frictionclutch surrounding the lifting-bar and actuated to produce the binding efect by tipping it slightly from a horizontal position, whereby the opposite sides of the clutch adjacent to the bar are forced against the latter, respectively, toward their upper and lower edges and in contrary directions. To accomplish this result, the clutch is provided with a projection extending from one of its sides and from the upper portion thereof away from the lifting-bar, at which the power (exerted from a lever to the lifting-clutch and from a suitable stop for the retaining-clutch) is applied to tip the clutch. This projection may not be of undue length, but, on the contrary, must be quite short, in order that the power for actuating the clutch may be exerted as closely as possible to the lifting-bar, thereby to permit the transverse dimensions of the lifting-jack to be reduced to the minimum, and which is of the first importance, to avoid the possibility of exerting too great a leverage on the clutch, which would tend to cause bending of the bar in producing against it the binding effect. Furthermore, the leverage being exerted at the side of the clutch from which the projection referred to extends, the binding power is produced, as it were, by pressing against the ad jacent side of the lifting-bar the upper portion of the inner surface of the clutch, and thereby also pressing the opposite lower portion of the inner surface against the opposite side of the bar. Thus the force of the gripping effect is not so great and positive with the exertion of a given power as if the binding were produced by pulling the grippingsurfaces of the clutch against therespectively adjacent surfaces of the lifting-bar.

The principal objects of my improvement are to provide means whereby the most effectual binding of the clutch against the liftingbar may be produced with the least exertion of power and to afford a construction of friction-clutch by means of which the greatest possible leverage capable of being exerted as close as possible to the lifting-bar may be attained with the shortest possible grippingsurface or grip, the latter, preferably, to afford the least or no space between the lower edge of the bin ding-surface on one side of the clutch and the upper edge of that on the opp osite side thereof,in order to avoid having any length or any material length of lifting-bar between the adjacent extremities of the bindin '-surfaces, which would, in proportion to the length of bar between such surfaces, render liable bending of the bar with the strain exerted.

My invention consists in the construction of the friction-clutch device in a lifting-jack, comprising, broadly, a bar extending across the lifting-bar, cross-bars extending from opposite ends of the said bar across opposite sides of the lifting-bar, and a handle rigidly connected or integral with and extending from one of the cross-bars at one side of the lifting-bar toward the opposite side thereof; and it further consists in the more specific construction and in combinations of parts.

In the drawings, Figure 1 shows in side elevation a lifting-jack having a portion of the handle of the operating-lever forlifting broken away, and provided with my improved clutch device applied both as a lifting-clutch and as a retaining-clutch Fig.2 shows in sectional elevation the same as is presented to View in Fig. 1. Fig. 3 shows in section the lifting and retaining clutches in their respective positions on a lifting-bar, the latter being indieated by dotted lines; and Fig. 1 shows a plan view 1113' the eluteh.

A is the lifting-jack, whieh as to all its parts, except the elnteh portion, may involve any 111 5 the known e11nstruetio11s to whieh my i111- proved 1 11111 11 device is applieable, that shown bei 11g 1 he one illustrated and deseribed in l1etters latent of the l'nited States No. 188,151 granted to me on the 21 st dayot' August, 1888,

to and involving the standard portion l1,li1ting bar (,hit'ureated lever D, 1ul1-1'u1ned at oppo site sides of its bitureated portion in reeesses r in the upper ends of the expanded part of the standard, links q, pivotally connected at their upper ends with the short arm of the lever and serving to eonneet the lever with the litting-elnteh device, and a guide-collar, :r, for the bar C, the eollar .1 being merely a web eonneeting the two sides of the expanded 2o portion of the standard and having a central opening for the lifting-bar, like the guide-e01- lar in various well-known forms of liftingjaeks, wherein it performs the same function 111' a guide surrounding the lifting-bar toward 25 the upper end of the standard.

ll 1n'y improved lifting-clutch, and E the retaining-eluteh, each of which involves substantially the same eonstrnetion, though, as 1 wish it clearly to be understood, either may 0 be employed for its purpose in a lifting-jack with any other suitable clutch-tl1at is, I may use my improved lifting-clutch with any other suitable retaining clutch, and vice versa; hence I do not herein limit myself to the em- ;55 ploynient of my improved. :t'orm e1? e1 11 1011 to both purposes in the same jaek.

The preferred construetion of the lilting- 1-1nt1'h 111 involves, as shown, two bars, on opposite sides 01. the 1il'1'ing-l 1ar, each of the 0 U shape shown, whereby a space, 0, is provided between the two integral or rigidly-eonneeted parts 11 and 111, and with one part, 11, longer than the other companion part, 111,21nd provided at its 1, .\'tre1nity with a lip forming 5 a handle, 7. The parts 112 ot' the two bars are joined at their adjaeent extremities by a eross-bar, 7.1, while the parts /1 are conneeted to one side of the e 'ts-bar 71' at the bases 01 the U-shaped bars by a cross-bar, 71.. The

space vertically between the eross-bars 711 and 72 is sufficiently wide to admit the lifting-bar, and it is preferred, though not essential, that the adjacent upper and lower edges of the cross-bars shall be on the same plane, 21s

shown, which plane, with the eluteh in its normal position on the bar 0, is a horizontal plane. The links 11 are pivotally connected at their lower ends with the lip forming the handle portion Z by being hooked into the latter.

By lowering the long arm of the lever .1) the eluteh E is tipped ifronl the handle portion 7, thereby 1.11.1l1ing the cross-bar 71 against one side of the lifting-bar and the cross-bar 71; against -the opposite side thereol', thus binth ing the bar 0 between the (moss-bars: and cans ing it to be lifted by the power applied at the operatinglever D. If the lower and upper edges, respeetively, of the two cross-bars 71' and 71 be on the same horizontal plane, as shown, there is no danger of the lifting-bar being bent by the binding strain exerted by th1'1tiltingo1 the el uteh, which is an advantage over having the said edges of" the cross-bars 7. and 71 on dillerent'horizontal planes, as they may be, sinee the liability to bend the bar inereases with distance bet-ween the horizontal planes eoineiding with the lower and upper edges oi. the respeetive eross-bars. 11y having the parts 11 extend from the rear crossbar or hearing, 71, and eonneeted with the lever 1) on the side 1113' the lilting-bar having the bearing 71', as shown, or near the same, a 1nueh longer leverage is obtained than if the handle portion at which to connect the clutch with the operating-1ever were merely in the t'orn11'1t2t projeet'ion t'ron1 thebeari 11g 71', whereby the gripping or binding ellj'eet would be produeed by the pushing l'oree luu'einbetore referred to.

\Vhile the eonstruetiml and form of. the el uteh E are preterabl y as described, the 1o1-n1 may be changed without thereby departing 1:1'0111 my invention, the important feature 01 which is to obtain the long leverage by extending the handle portion of the clutch from the hearing or cross bar on one side of the lifting-112111110 or toward the opposite side of thelifting-bar. Thusan entire side, 1'11 11 7, may be omitted, leaving the elntch formed of only one sidem 11 7 and end portions, 7.' and 71, or the bearing-bar 71 maybe loosely supported or jonrnaled in its position on the clutch i11- stead o1? being integral therewith, as shown, when it may have the term of 1he roller, or the part: or parts 11. may extend short of the side of the lilting-bar at whieh the e1ossbar 71' is located instead of extending beyond the same, as illustrated. These ehanges are so obvious that it is not eonsiderml neeessary to illustrate them.

The retaining-e1u1eh E etnnprises 21 e011 stru1j1tion (as shown oras stated to be ehangeable) very similar to the elutch E, inasmuch as it involves parts on and 11. like the parts 111 211111 11 and separated by a spaee, 0, and cross or bearing bars 71 and 71' like the bars 71 and 7t. The handle portion 7 on the parts a may be longer than the handle portion or lips I, to extend over and be lulerumed at the outer edge of the base 111' the expanded portion of the standard, and thus afford means for releasing the gripping etl'eeto't' the retaining-eluteh on the lifting-bar. The clutch E, as will be seen, is adjusted upon the liftingbar in a manner to cause the handle portion Z to extend in a direction eo'ntrary to that in which the lips Z extend.

The tendeneyot' the eluteh E is to tip from the supported handle portion Z toward the opposite side, both by its own weight and by that of the lifting-bar and load on the latter, whereby it binds the bar, as in the ease of the clutch E. By pressing downward upon. the handle the clutch E is forced to a horizontal.

position, thereby releasing its holding effect upon the bar.

What I claim as new, and desire to secure by Letters Patent, isv 1. In a lifting-jack, the combination, with the standard and lifting-bar, of a frictionclutch having a bar extendin across the lifting-bar, cross-bars extending from opposite ends of said bar across opposite sides of the lifting-bar, and a handle rigidly connected or integral with and extending from one of said cross-bars at one side of the lifting-bar toward the opposite side of the latter, substantially as described.

2. In a lifting-jack, the combination, with the standard, lifting-bar, and operating-lever, of a friction-clutch, E, having a U-shaped bar, 1), composed of rigidly-connected or integral bars m and a, a cross-bar, 7;, extending from the bar on across one side of the liftingbar, and a cross-bar, 71 extending across the opposite side of the lifting-bar, and a handle portion, Z, on the bar 72, connected by a suitable link-conn ection with the operating-lever I), substantially as described.

3. In a lit'ting-jack, the combination, with the standard, lifting-bar, and operating-lever, of a lifting-clutch, E, comprising two U shaped bars, 1), embracing the lifting-bar and each composed of the rigidly-connected or integral bars m and 'n, a cross-bar, Z5, connecting corresponding ends of the bars m at one side of the lifting-bar, a cross-bar, h, extending between the bars 1) across the opposite side of the lifting-bar, and a handle portion, Z, forming extensions of the bars a, connected by a suitable link-connection with the operatinglever D, and a suitable retaining-clutch, substantially as described.

4. In a lifting-jack, the combination, with the standard, lifting-bar, and operating-lever, of a lif tin g-clutch, E, comprising two U -shaped bars, 2], embracing the lifting-bar and each composed of the rigidly-connected or integral bars at and n, a cross-bar, 7;, connecting corresponding ends of the bars on at one side of the lifting-bar, a cross-bar, 71, extending between the bars 1) across the opposite side of the lifting-bar, and handles Z, forming extensions of the bars 11, extending beyond the side of the lifting-bar at which the cross-bar It is provided, and connected by a suitable linkconnection with the short end of the operating-lever D, and a suitable releasing-clutch, substantially as described.

5. In a lifting-jack, the combination, with the standard, lifting-bar, and operating-lever, of a suitable lifting-clutch and a retainingclutch, E, having a U-shaped bar, 19', C0111- posed of rigidly-connected or integral bars at and n, a cross-bar, 7t, extending from the bar m across one side of the lifting-bar, and a cross-bar, h, extending across the opposite side of the lifting-bar, and a handle portion, Z, on the bar a, at which the clutch is supported on the standard, substantially as described.

6. In a lifting-jack, the combination, with the standard, lifting-bar, and operating-lever, of a suitable lifting-clutch and a retainingclutch comprising two U-shaped bars, 1:) embracing the lifting-bar and each composed of the rigidly-connected or integral bars m and a, a crossbar, Z connecting corresponding ends of the bars m at one side of the liftingbar, a crossbar, h, extending between the bars 1) across the opposite side of the liftingbar, and a handle portion, Z, forming extensions of the bars a, and at which the retaining-clutch is supported on the standard, substantially as described.

'7. In a lifting-jack, the combination, with. the standard, lifting-bar, and operating-lever, of a suitable lifting-clutch and a retainingclutch, E, comprising two U-shaped bars, 1), embracing the lifting-bar and each composed of the rigidly-connected or integral bars m and n, a cross-bar, k, connecting corresponding ends of the bars at at one side of the lifting-bar, a cross-bar, 71, extending between the bars 19 across the opposite side of the lifting-bar, and handles Z, forming extensions of the bars 01', extending beyond the side of the 1it'tingbar at which the cross-bar k is provided, and affording a lever for releasing the IGbitll'lillg-Cllll'fiil at which it is supported on the standard, substantially as described.

AXEL A. STROM.

In presence of J. W. DYRENFORTH, M. J. BOWERS.

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