US60442A - Otis tufts - Google Patents

Description

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Be it *known that I, Oris Tur-rs, of Boston, in the county of Suffolk, and State of-Massachusctts, have invented an Improvement in Elevators; and 1 do hereby declare that the following, taken in connection with the drawings which accompany and form part of this specification, isis descriptionpf my invention suilicient to enable'those skilled in the art to practise it.

This invention relates to improvements upon my invention patented May 28th, 1861, in such elevators as make use of a car guided between ways and suspended from its upper end by two or moreropes or chains, which have the ends of each separately attachedt the top oi' the car and tothe winding drum; And my herein described invention consists in s. peculiar srrangementcf pivoted links herein described, operating automatically to equalize the strain upon a series of ropes or chains, attached eacl'v by one end, separately thereunto, primarily' and secondnrily thereby to the top of a guided and suspended elevator car, and each by the otherv end to a winding drum. i

i The object of my invention is the same as that of the strain-equalizing device described in my aforesaid patent, but the construction of the within described device being different, and toda considerable extent better and cheaper for some purpose; it ishgreinelaimed as an improvement,"

Figure 1 of the drawings shows in front view an elevator embodying my invention. Figure 2 is a vertical central section taken in the plane of the line z z, iig. 1.

Figure 3 is an elevation of my improvedautomatic adjuster of the strain on the tensile supports, the scale' being larger than that shown in g. 1; and

Figure 4 is n.l detail introduced merely to show how the-automatic strain adjusterV may be located. at the l drum, instead of at the top of the csr, though I would remark that such a changeis not accompanied with any beneficial results.

The 1st and 2d figs. of the drawing show plainly the general arrangement of an elevator, in which the car is guided by ways, and is suspended from its upper end by a series of ropes or chains-which pass over a guiding pulley to a winding drum, all of which forming no part of my present invention, will not bc .more particularly referred to herein.

Pivoted to a suitable casting, r1, which is securely fixed at the top of the car, is a series of double or oppositeliuks, exceeding in the number of pairs thereof the` number of suspending ropes' or chains, b lz b by one.

i Of these links the extremes, `c c, of the series are longer than the intermediates, d d d, which have but two pivot centres, e and f, while the extremes have three pivot centres, e, f, and g.- Each of the centres ffff f, are

' connected with each of thc adjoining centrcsf, by pairs of links, h h h, said links also taking hold of crossconuecting bars, 'i i z', on which the links h pivot, each of said bars serving for a point of attachment of one end ofAone of the ropes b. The tops of the links c c are united by a pair of connecting links, j, pivoted at y g, and acting as a strut or brace to keep the extreme centres f from approaching each other under the strain upon the ropes or chains b b b b. The arrangement of all of these links `in pairs enables mc to connect the ropes b b b l?, centrally between them to the bars z'z'i, and the pair of links j, are so united by studs lc, that they act together as one link with the ropes passing between its twopsrts.

The opera-tion of this apparatus is as follows: lf all the rcpes'are of an exact'length from the points where, as tangents, they touch the periphery of the winding arm, to the points of their` attachment to the bars t' z', and if there is the same strain on each rope or-chain, then the angles formed by the links h will all be equal to each other, and the links c d d d c will be vertical. Suppose, now,.one of the ropes to shrink or to shorten from any cause, it is evident that it will either sustain the whole wcight'of the car and itscontents, leaving the other ropes slack, or else that the links h will so move as to bring an equal stress on all of the ropes'. Thclatter will he the case, as it is clear that the links It', embracing that piece which receives thc shortened rope, will forni-a more acuto angle by rising, which act causes the other links lto descend and form more obtusc'anglcs, while the links d will swerve from their vertical position toward the shortened rope, and the strain on all the ropes will he thus automatically adjusted to su eqnal strain on each. If one of the ropes stretches, then the links which are connected to those pieces to which the other ropes are attached, rise, While the links attached to the piece which receives the lengthened ropefttll, the links d inclining from the lcngthened rope, and the strain,

the position of its parts,

s automaticallyl adjusted on all the ropes provided, as also in the previous instance, that the change in the condition of the ropes is not too great for thc range of action of the adjusting mechanism, When one ormore of the ropes break, then the car falls till the links L, attached to the piece or pieces 2', receiving the broken rope or ropes, assume a horizontal position, the other links L forming smaller angles than before such breakage, and

the stress will then be automatically transferred equally to the ropes remaining whole. The object of pivoting the links c at the bottom, as the links d are pivotcd, is to allow the whole system oi links to sway from right to left, or vice versa, according as thc tendency of the draught of the ropes inclnes the syste-m to move with reference to the centre of gravity of the suspended car. Except for the advantages derived from the swinging movement of the entire systemy of links, the cxtreme links 7L might be pivotcd to immovable supports, andl yet the system so modified would operate as described in respect to automatically equalizingth'c strain onthe ropes or chains. As the range of motion of the parts of the described apparatus is but comparatively small, and as it s necessary for its operation that the length of the ropes should be such as to causo the links to assume about a medium position between thoseV extremes of' movement which, under the contemplated contingencies inproctical operation, they may be caused to make, so that under changes of the conditions of theropcs or chains any of their points of attachment, z'z'z'z', may be free to move up or down, it is extremely desirable to combine with an automatic adjuster of the strain 'upon the tensile supports, some convenient means `ior so adjusting, by manipulation, the length of such supports, as that thereby the automatic adjuster may itself be adjusted as to to bring them to a mean of the extremes of their limit of motion. This I accomplish asfollows: Each rope or chain b forming one of the tensile supports of-the guided and suspended car, is attached to the winding drum m, as follows: Tubular screws, Z, are made, through which the ropes or chains can pass, and to which they are secured by enlargements thereof, which cannot pass through the bore of' the screws, which by turning, A,can be adjusted in the drum relative to its periphery, thus lengthening or shortening the effective winding length of thc tensile supports, so that the centres of the pieces z' z' z' z' may all be brought to the same line, from which they depart on account ofvarious reasons, in the actual use of the elevator, causing the said centres to assume positions not in the saine line or plane, as illustrated by red lines in Eg. 3.

I claim, forthc purpose of automatically' adjusting the strain upon the ropes or chains 6 b, the mechanism herein described, when arranged to operate substantially as specified. V v OTIS TUFTS. lVitnesses:

J. B. Ciaosnr, W. B. GLEAsoN.

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