US571864A

US571864A - Gearing for elevators

Info

Publication number: US571864A
Authority: US
Publication date: 1896-11-24
Anticipated expiration: 1913-11-24

Description

(No 4Model.) 2 Sheets-Sheet l. E. B. PARKHURST.

GEARING FOR ELEVATORS.

N0. 571,864` Patented NOVn 24, 1896.

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E. B. PARKHURST. GBARING POR BLBVATURS.

Patented Nov. 24, 1896;

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EDlVARl) B. PARKiflUR-ST, OF NVOBURN, l\IASSAClUSET"S.

(BEARING FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 571,864, dated November 24, 1896. Application filed November 18, 1895. Serial No. 569,274. @in modela To all whom it' may concern:

Be it known that I, EDWARD B. ilannr-iunsr, citizen of the United States, residing at lVobnrn, in the county of Middlesex and State of lllassachusetts,have invented certain new and useful Improvements in Gearing for Elevators, of which the following is a speciiication, reference being had therein to the accompanying drawings.

The invention relates more particularly to elevators of the general class in which the car or platform is operated by means of gears mounted on the said car or platform engaging with fixed or stationary racks and operated hy rotating Wo1nis,\vlx.ich also are carried hy the car or platform.

The object of the invent-ion is to simplify the gearing intermediate the Worms and the racks and to reduce the number of parts to the greatest possible extent.

The invention will first 'he described withv reference to the accompanying drawings, af-

ter which its distinguishing features will he more particularly pointed out and distinctly defined in the claims at the close of this specification.

In the accompanying drawings, Figure l, Sheet 1, is a view mainly in side elevation, but with some of the parts in vertical section, of an elevator having my invention applied thereto. Fig. 2, Sheet 2, a view in elevation, partly in section, of certain details thereof. Fig. 3 is a vieny of the worm and gear which are represented inv Fig. 2, viewing them from the left in the latter figure.

Fig. a is a view in elevation of portions ofv one of the racks and its support,

The preferred application of my invention is in connection with an electric elevator, and I have shown it thus applied in Fig. 1 of the drawings.

At lin the drawings is a car or platform of an elevator. l have herein shown a car or platform like that in common use for freightelevat-ors, although it is to he understood that the invention is applicable to elevator-cars of other descriptions as Well.

:2 f3 are fixed or stationary uprights between which the car or platform 1 moves. As will be obvious, a Well may be employed instead. of these nprights, or the uprights may loe einployed in a Well, and so far as this part of the construction is concerned there need be no departure from what is in common usc. On the uprights 2 2 are secured racks 3 3.

l is a framerat the under side of the car or platform and connected therewith. This frame serves for the support of the operating mechanism for the car or platform.

5 5 are gears the teeth of which engage with the teeth of the racks 3 3, said gears being mounted on the car or platform and heing rotated by devices mounted on and can ried by the said car or platform, asl nowwill proceed to describe.

At 6 6 are Worms engaging with the gears 5 5 for the purpose of turning the same, and 7 is a shaft on which the said Worms G G are Iixed. Preferably the shaft 7 has fixed thereon the armature S of an electromagnet D, "whereby it is rotated in the desired direction on the passage of an electric current through the Wi ring of the said magnet.

Each gear 5 5 meshes directly with the adjacent rack E3 and also with the adjacent Worm U, and thus serves both as a spnrpinion and as a worm-gear. illeretofore it has been found necessary to employ more than one gear intermediate cach Worm and the adjacent rack, inasmuch as a single gear of ordinary construction is not fitted to serve both as a Worm gear to coact with the Worm and as a spur gear orpinion to eoact with the rack. It is found necessary in practice, in the case of a wormgcar, to form the surfaces of the teeth thereof on an incline relative to `the axis on which the Worm-gear rotates corresponding with the inclination of the thread of the Worm. Spur gears and pinions have the intermeshing surfaces of the teeth thereof formed parallel with the axes on which the said gears rotate. In accordance with my present invention I form one side 51 of every tooth of each gear 5 inclined to correspond with the thread of the Worm 6, and I form the opposite surface 52 of over f tooth of such gear 5 parallel with the axis of the gear 5, to thereby nt it to Work against the teeth of the rack 3. These features are most clearly shown in Fi gs. 2 and 3. In other Words, I forni every tooth of each gear 5 with one surface thereof in-V clined relatively to the axis of rotation of the said gear to correspond With the inclination of the thread of the adjacent Worm G, and I ICO form the other surface of every tooth of said gear parallel with the aXis of rotation of the gear. As will be understood, the teeth 3l of each rack 3 have horizontal Working' surfaces 32, with which the surfaces 52 of the teeth of the corresponding Worm-gear 5 engage. The tapering form possessed by the teeth of each gear 5 enables me to forni the teeth 3l of each rack 3 tapering also, which I do for the purpose of strengthening the said teeth 3l by the introduction of more metal into the saine in the broader portions thereof. I secure further strength by connecting the ends of the teeth on each rack by means of Webs 33, extendinglongitudinally of the rack at each side thereof.

I claim as my invcntionl. The combination with vertical racks, as 3, 3, of an elevator' car or platform, gears mounted on said car or platform and provided with teeth each having' one surface thereof inclined relatively to the axis of the gear, as in the ease of a Worrn-gear, and the other surface thereof parallel with said axis to engage with the teeth of the adjacent rack, Worms in engagement With the inclined surfaces of the teeth of the said gears, and means to rotate the said Worms, substantially as described.

2. The gear herein described having each tooth thereof provided With one surface which is inclined relatively to the axis of the gear, as in the case of a Worin-gear, and the other surface thereof parallel with the said axis, as in the ease of a spurfgear, substantially as set forth.

In testimony whereof I affix my signature in presence of tWo Witnesses.

EDWARD B. PARKIIURST.

lVitnesses:

WM. A. MAcLnoD, CHAs. F. RANDALL.