US87143A - Improvement in hoisting-apparatus - Google Patents

Description

.PETERS. FHDTO-LITHBGRAPHER, WASHINGTON. D. C.

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DEXTER H. CHAMEEELAIN, or WEST RoXBURY, MASSACHUSETTS.

Letters Patent No. 87,1143, dated February 23, 1869.

IMPROVEMENT IN HorsT'INe-APPARATUS. 'H

AThe Schedule referred to in these LettersPatent and making part of the same.v

To all whom it may concern Be it known that I, DEXTER H. GHAMBERLAIN, of West Roxbury, in the county of Norfolk, and State of Massachusetts, have invented certain Improvements in Elevators, or Hoisting-Apparatus, of whic hthe following isa full, clear, and exact' description, reference being had to the accompanying drawings, making part of this specication, in which- Figure l is a perspective view of my improved elevator as applied to a building.

Figure 2 is a vertical longitudinal section through the same.

Figure 3 isa horizontal section on the line x x of fig. 2.

Figure 4 is a perspective view, representing the 0011-. struction o f my sectional screw-shaft.

Elevators, or hoisting-apparatus, provided with a revolvin g screw-shaft, are objectionable for various -rear sons, some of which will be here enumerated.

Owing to the great length of the screw-shaft, it is found necessary to make it in sections, and steady it by a series of open bearings formed within braces projecting from the sides of the walls,and placed at suitable intervals between the extreme upper and lower fixed bearings, by which construction it is impossible to employ a shaft with a continuous screw-thread for driving the screw-nut attached to the carriage of the elevator, and it is therefore onlyja small number, or a limited portion of the threads, which simultaneously engage with or mesh into each other, which fact, together with that of the resistance or weight being removed so far from the power, subjects the screw-shaft to a very considerable torsion, which is unfavorable to the regular and uniform transmission of the power, to overcome which diiiiculty the shaft must be made of large diameter, which is not only unwieldy, but very expensive. v

When a shaft so constructed is revolving rapidly, the amount of vibration produced is so great as to shake and endanger the safety of the building in which it is placed. l

It therefore becomes necessary to give the threads l ofthe screw-shaft a steep pitch,7 and revolve it slowly, but ou account of the expenseand diiiculty of making an accurate'steep pitch, and the rapidity with which it wears away, by its threads becoming thin and beat out, it is also ,exceedingly objectionable.

'lhe torsion above referred to also deranges the position of the threads of the screwfshaft relatively with those of the screw-nut on the carriage, so that they will not readily engage therein, and are frequently upset and rendered worthless. I

To obviate the above-mentioned difiicultles is the object of my invention, which consists in a non-revolving screw-shaft, loosely suspended or supported in movable bearings, in contradistinction to a screw-shaft re-L volving in iixed bearings, the shaft being; provided with a vertical longitudinal groove, for the reception of a spline in the cross-head or in the platform of the carriage, for preventing the revolution ofthe Shaft, While a nut, directly or indirectly in contact with the crosshead or platform, is revolved by worm-gear, or otherwise, to raise and lower the carriage and its load, as

required, the shaft being always free to adjust itself to its proper position for insuring the smoothand uninterrupted action of the nut thereon.

My invention also consists in a continuous screwshaft formed in sections, fitting into and securely united together, the union or connection being formed between the homogeneous ends of the respective sections, by which means I am enabled to avoid the use of sleeves and intervention of bushes incident to the construction of other sectional screw-shafts for elevators.

My invention also consists in certain other improvements, of minor importance, to be referred to hereafter.

To enable others skilled in the art to understand and use my invention, I will proceed to describe the manner in which I have carried it out.

In the said drawings- .A is the base, or foundation m the basement of the building, lto which the elevator is to be applied.

Vithin this foundation are secured the lower ends of two vertical posts or beams, B B, which extend up the sides of the well7 or area to beo'ccupied by the elevator, and are united' at their tops by a horizontal beam, C. l

, D D are guides, or ways, upon'which the cross-head E and platform F of the elevator-carriage slide. V

The platform and cross-headare securely connected together by means of two vertical posts or stanchions, l0 10.

i3 is a circular tube, projecting up from the centre of the platform, through which, and the centre of the vcross-head, are formed circular openings, for the passage of an upright screw-shaft, H, which is composed of a series of hollow sections, a, the lower end, b, of

` one section being tenoned or turned down, so as to accurately and snugly iit into thetop, c, ofthe circular recess in the other section. (See figs. 2 and 4.)

I is a wire rope, which passes through the centre of each of these sections, and thence loosely through an aperture in the horizontal beam O, the top of the wire rope being provided with a screw-plug, d, over which turns a screw-nut, e.

The lower end of the wire rope, I, terminates in a circular projection orfoot-piece, f, upon which rests a hollow cylindrical section, g, of the same diameter as the section of the screw-shaft above it, by which construction-'it will be seen that the entire hollow screwshaft is hung upon the wire rope, which-.is loosely suspended from the beam 0,-while the bottom of the screw-shaft is free to move slightly in a lateral direction, for a purpose presently to vbe explained.V

The several sectional screws are each provided with a longitudinal groove,h, which, when the sections are tted together, form a long vertical groove, extending the Whole length of the screw-portion of the shaft.

Within this groove lits a spline, c', secured to the cross-head, and projecting into the circular aperture made therein for the reception of the .screw-shaft, the object of the spline being to prevent it from revolving, and thus avoid the vibration and torsion incident to screw-shafts which are-made to revolve.

Thecarriage ofthe elevator' is caused to ascend and descend upon the non-revolving screw-shaft by means of the revolution of a circular screw-nut, K, which surrounds and turns thereon, this feature being in contradistinction to a revolving screwshaft engaging into a screw-nut attached to the carriage.

To the top of the screw-nut K is secured a wormwheel, L, directly upon which the cross-head rests.

This worm-wheel L, (and consequently the nut with it,) is driven by a worm-screw, M, on a horizontal shaft, N, which has its bearings in lugs or braces, k, projecting from the opposite ends of the ciosslliead, this shaft N passing through a cylindrical sleeve, O, and terminating at its outer4 end in a serrated or'notched whorl, l. Y

T he sleeve 0 is provided, at its outer end, ywith an arm, P, at right .angles thereto, from the extremities of which proceed studs, m m, which serve as stationary axes upon which the sheaves a a are made to revolve, by means of power transmittedthrough a belt, Q, which is ledover a drum, It, on the dri\f'ing-shatt around the sheaves m fm and whorl I, and thence up over a drum, S, the sleeve O being prevented from revolving by means of a pin, o, passing through a flat projection, p, into one ofthe braces 7.', from which construction it will be seen that the worm-shaft N, with the sheaves m m, rises and falls in common with the elevator.

As the screw-nut turns up o1' down, (carrying with it the-carriage,) the non-revolvin g screw-shaft H, being4 suspended loosely by the wire rope I, is free to oe arljusted by the movable nut K into'a vertical position,

,without being cramped thereby, the threads of the shaft and nut being made of the required fineness and pitch to enable the nut to be driven smoothly, and at a uniformly high rate' of speed, without causing any vibration, and almost an imperceptible, if any, torsion, the torsion, should any be produced, being in the wake of the nut.

i Instead of a wire rope passing loosely through the sectional screw-shaft, a rod, or rope of other material may be employed for suspending the shaft, and the rod or rope may be soldered, or otherwise secured to the sectional shaft, if desired.

The rod or rope' may also be dispensed with, and the shaft be suspended by a link, or other connection, at its to'p, or it may be supported in a movable bearing at or near its bottom; and furthermore, a nonfrevolving sectional screw-shaft may pass through each side of the elevator, instead of through its centre, and the screw-nut K may be placed under the platform, and

where the elevator is only required to ascend a short distance, the screw-shalt may be made in one piece,4 instead of in sections, if preferred. without departing from the spirit of my invention.

Vhat I claim as my invention, and desire to secure by Letters Patent, as an improvement in elevators or hoisting-apparatus, is

The non-revolving screw-shaft, suspended substantially as and for the purpose set forth.

I also claim a continuous sectionalscrew-shaft, as and for the purpose set forth. f

I also claim two or more sections of a continuous screw-shaft, united together' by homogeneous tenons at vtheir ends, substantially as and for the purpose de scribed. i

I also claim the arrangement of the revolving screwnut K, and a non-revolving screw-shaft, H, provided with a groove, h, the steadying-spline t', either in the cross-heads E or platform F, for the purpose specified.

DEXTER H. GHAMBERLAIN. IVitnesses:

N. W. S'rnAnNs, L. E. BATOHELLER.

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