US2537075A

US2537075A - Compensating apparatus for elevator hoisting roping

Info

Publication number: US2537075A
Application number: US53647A
Authority: US
Inventors: Margles Samuel Gustave
Original assignee: Otis Elevator Co
Current assignee: Otis Elevator Co
Priority date: 1948-10-09
Filing date: 1948-10-09
Publication date: 1951-01-09
Anticipated expiration: 1968-01-09

Description

Jan, 9, 1951 s. e. MARGLES 2,537,075

COMPENSATING APPARATUS FOR ELEVATOR HOISTING .ROPING Filed Oct. 9, 1948 2 Sheets-Sheet l M 6 INVENTOR ATTORNEY a, e. MARGLES Jan. 9, 1951 COMPENSATING APPARATUS FOR'ELEVATOR HOISTING ROPING Filed Oct. 9, 1948 2 Sheets-Sheet 2 .4! Al I 40 SM GMW INVENTOQ I AT TOR NET Patented Jan. 9, 1951 um STATES; PATENT OFFICE.

GOMPENSA'IING APPARATUS F03, ELEVATOR HQISTING ROPING Sannnet- Gustave Margles, Brooklyn; N Ya, as

signer to Otis Elevator Company, New York, N. Y.',. av corporation of New Jersey Application October 9, 1948, sen-rains. 53547 (CL R F -22) il' Gl-aims;

The invention relates to compensating apparatus for elevator hoisting roping,

In elevatorinstallations of'the traction type, the elevator car and'counterweight'are suspended by hoisting ropes which pass over a hoisting" sheave at the top ofthe hoistway, It is usual'i'n such installations to compensate for the unbalanced'weight of the hoisting, roping as the car andcounterweight' move up and down in the elevat'or hoistway; In most of" these installations this compensation'is effected by roping which is suspendedifrom the car and" counterweight, this roping passing around a sheave,, termed' 8;, compensating sheave, ,at' the-bottom .ofthe hoistway. In certain installations chainjcompensationhas been utilized: In installations where, compensa-.- tion is provided, it'is desirable to make the connections to the car and" counterweight at such points as to minimize thrusts on the guide shoes.v

Existing conditions may make it necessary in an elevator installation to have ashallow pit below'the lower terminalfloorh Thus where compensating sheaves are employed,1 it1is desirable thatthey be' arranged" to utilize a minimum of vertical space.

There are-certainadvantages invchain compen-. sation; One ofthe more importantlofjthesead' vantages resides in the low costl However, chain compensation has not heretofore been provided in any except slow spjeedinstallations because of the noise of the chain in operation,

One'feature ofthe" invention i'sito'provide chain compensationwhich is quiet in operation.

Another feature of the invention i's tO provide chain compensation of this character which is suitable for: installations having shallow pits.

Still anotherfeature of the invention is to provide' a compensating arrangement in which the compensation is efiectedsoas to minimize any thrust on the guideshoes for the car and'counterweight.

Other features and advantages will become apparent from thefollowingdescription and appended claims;

In carrying out the inventi'on according to the arrangement which will be -described; the compensation isefiected by a pair of chains, each secured at one end to'the' elevatorcar and extend ing downwardl'yinto the 'hoistway pit and thence upwardly to the counterweight towhichitsother end is connected; Atithe bottom each chain passes around apair' of small sheaves mounted in horizontally spaced relationship" in' a frame" arranged to' permitx vertical movement. The sheavesareiprovidedwithzaifacing of soundidead Y quired' for the" compensating'" apparatus.

china resilient non meta'llic material grooved to" accommodate the chain; therebyminimizing any noise of chain operation: Also the small sheaves minimize the amount of vertical pit" room re- The chains are connected to the car" and counterweight with respect to the centers of gravity thereofso-as to' minimizeany' thrusts on thegui'd'e Also the connections are made so as toshoes: enable one buffer to be usecl'for" thecarandone' for the counterweight, witheachbufieracting in the line" of" the center of gravity of" the body" for which it is provided; This is' effected by connecting' thechains toeachbodyone on each side of" the buffer for thatbody and symmetrical with re spect to the center of gravity ofthe'body: Variations' may be madein' certain instances in case of the car to' balance the travelling cable's.

In the drawings Figure 1 is a schematic trimetric' representation of an elevator installation embodying the invention;

Figure 2 is a plan view of the compensating sheaves'and frame for one of the compensating" chains;

Figure 3"is a View of thesame" in elevation; il-

lustrating also the-connection of the chain to the car and counterweight Figure 4' is a viewi'n section taken along; the line i -4 of Figure 3;"and' Figure 5 is a view'with parts in section ofjone of the compensating'sheaves.

Referring tohigure 1; the elevator car it) and ing these members to 'astop should'they'continue into the elevator pit during' downward movement: The car buffer is mounted on the'fioor' iiiof the pit whereas the counterweight bulfer" is carriedbythe counterweightitsel-ffi Compensation for the unbalanced weight (ii-"theropes is provided by

twospaced chains

28 and 21;

Each compensating chain extends downwardly" from the'elevator car around a pair of sheaves- 22 and 230i atensioning devicez i-in theel'evator pit and thence. upwardly to the counterweight;

Thetensioning devices-are ofthe same construction. The construction of one of'thesetension ingdevices and the manner of connectingacom pensating-ichain' to the car and-counterweight is 3 illustrated in Figures 2, 3, 4 and 5 to which attention may now be had.

The chain is illustrated as of a straight link construction. At the car the chain is connected through an S hook 25 and hitch 26 to a plate 27. This plate is'secured to the plank channels 28 mounted beneath the car platform 39 and together with upright channel 3! forming part of the car framework. The other end of the chain is secured to the counterweight through a hitch 32 and anchor bracket 33 bolted to the counterweight frame.

The tensioning device 24 comprises a frame 3d having a pair of side plates 35. These side plates are secured in spaced relationship by means of cross plates 36 secured to L-shaped angles 31 in turn secured to the side plates. These side plates support the shafts 38 for the compensating

sheaves

22 and 23. These shafts extend in spaced relationship crosswise of the side plates and are secured to the frame by nuts 41] on the threaded ends of the shafts. The spacing of these shafts is determined by the character of the installation. Arranged on each shaft is a pair of ball bearings 4| on which the comepnsating sheave is mounted. Each sheave has a grooved rim 42 provided with a facing 43 of sound deadening resilient non-metallic material such as rubber. Neoprene has been found satisfactory because of its oil resistant properties, espec-ally in View of the fact that it is considered desirable to oil the chains. The neoprene is vulcanized to the rim and formed with a groove M to accommodate the chain. Bolts 45 at each end of the frame are provided to retain the chain in the grooves of the compensating sheaves.

Guides 511 and iii are provided on the outside of each of side plates 35 at the top and bottom thereof. These guides cooperate with

vertical guide rails

52 and 53 to guide the frame and therefore the compensating

sheaves

22 and 23 for vertical movement. These guide rails are secured by means of L-shaped brackets 55 to a channel member 56 extending crosswise of the pit. At their upper ends, the guide rails are braced through

angle members

57 and 58 fastened tostructuer not shown at the sides of the pit. The tensioning frame and sheaves have sufficient weight in themselves to maintain the chain taut.

A switch 6:] is mounted on the guide rail 52 by means of a bracket 6|. This switch is provided with an operating arm 62 adapted to be struck by the arms 63 of spaced angles 64 mounted on the tensioning frame. With this arrangement should the tensioning frame move downwardly beyond a certain point or upwardly beyond a certain point the switch is operated. This switch is arranged to cause the stopping of the hoisting motor should this operation take place. Thus any danger of the tensioning device resting on channel 55 or being struck by the car or counterweight is minimized.

The compensating chains 20 and 2| are connected to the car and counterweight so as to be symmetrical with respect to the centers of gravities of the bodies. This obviates side thrusts on the guide shoes which is especially important when rubber tired roller guides are employed. One arrangement is illustrated in Figure 1. In this arrangement, connection is made to the counterweight so that thevertical portions of the chains suspended from the counterweight are in a plane parallel to the front of the counterweight and through the center of gravity of the counterweight, with the chains equally spaced on each side of the center of gravity. Also the chains are connected to the car so that the vertical portions suspended from the car are in a plane parallel to the plane of the chains suspended from the counterweight and through the center of gravity of the car, with the chains equally spaced on each side of the center of gravity. The connection of the chains to the car may be made off the physical center of the car where the car door and door operating mechanism throws the actual center of gravity to the door side of the physical center. Also, it may be desirable to connect the chains somewhat off the center of gravity to provide a moment to balance a moment due to the connection of the travelling cables to the car.

It is important that the buffer for the counterweight apply its force at the center of gravity of the counerweight. This is accomplished by spacing the points of connection of the chains to the counterweight equidistant from the center of gravity of the counterweight which enables the counterweight buifer to be mounted in line with the center of gravity of the counterweight. It is also important that the buffer for the car apply its force at the center of gravity of the car. This is similarly accomplished by spacing the points of connection of the chains to the car equidistant from the center of gravity of the car which enables the car buffer to be mounted in line with the center of gravity of the car.

With the above construction chain compensation is provided which is quiet in operation. Also tensioning apparatus is provided which is suitable for shallow pits. In addition the compensation is effected so as to obviate side thrusts on the guides. Also the compensating frames for the chains enables weights to be added where it is desirable to increase the traction on the hoisting sheave.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An elevator installation wherein the elevator car and its counterweight are suspended by hoisting roping and wherein apparatus is provided for compensating for the unbalanced weight.

of the hoisting roping, characterized by the fact that said compensating apparatus comprises a chain connected at one end to the car and at the other end to the counterweight and a tensioning device for the chain at the bottom of the elevator hoistway, said tensioning device including a sheave having a facing of sound deadening resilient non-metallic material around which the chain passes.

2. An elevator system comprising, an elevator car, a counterweight, a hoisting sheave, hoisting roping connected to said car and counterweight and extending over said hoisting sheave, a compensating chain for said hoisting roping connected at one end to the car and at the other end to the counterweight, and a tensioning device for said compensating chain including a sheave with a rubber tire around which the chain passes.

3. An elevator installation wherein the elevator car and its counterweight are suspended by hoisting roping and wherein apparatus is provided for compensating fo the unbalanced weight of the car, a counterweight, a hoisting sheave, hoisting roping connected to said car and counterweight and extending over said hoisting sheave, a compensating chain for said hoisting roping connected at one end to the car and at the other end to the counterweight, and a tensioning device for said compensating chain including a pair of spaced rubber tired sheaves around which the chain passes and a frame for mounting said rubber tired sheaves.

5. An elevator installation wherein the elevator car and its counterweight are suspended by hoisting roping and wherein apparatus is provided for compensating for the unbalanced weight of the hoisting roping, characterized by the fact that said compensating apparatus comprises a pair of spaced chains, each suspended at one end from the car and at the other end from the counterweight, and a tensioningdevice for each chain at the bottom of the elevator hoistway, each tensioning device including a pair of horizontally spaced sheaves around which the chain passes, each having a rubber tire grooved to accommodate the chain.

6. An elevator system comprising, an elevator car, a counterweight, a hoisting sheave, hoisting roping connected to said car and counterweight and extending over said hoisting sheave, a air of spaced compensating chains for said hoisting roping, each connected at one end to the car in a given relationship to the center of gravity of the car and at the other end to the counterweight in a given relationship to the center of gravity of the counterweight, and a tensioning device for each compensating chain, each tensioning device including a pair of grooved rubber tired compensating sheaves around which the chain passes and a frame for mounting said compensating sheaves in horizontal spaced alignment.

'7. An elevator installation wherein the elevator car and its counterweight are suspended by hoisting roping and wherein apparatus is provided for compensating for the unbalanced weight of the hoistingroping, characterized by the fact that said compensating apparatus comprises a pair of chains extending from the car to the counterweight, said chains being connected to the car in spaced relationship and symmetrical with respect to its center of gravity and being connected to the counterweight in spaced relationship and symmetrical with respect to its center of gravity and a tensioning device for each chain at the bottom of the elevator hoistway, each tensioning device including a pair of grooved neoprene tired compensating sheaves around which the chain passes and a frame for mounting said compensating sheaves in horizontal alignment and spaced so that the chain hangs vertically from the car and counterweight.

8. An elevator system comprising, an elevator car, a counterweight, a hoisting sheave, hoisting roping connected to said car and counterweight and extending over said hoisting sheave, a pair of compensating chains for said hoisting roping extending from the car to the counterweight, means for connecting said chains to the counterweight in a plane parallel to the front of the counterweight and through its center of gravity, with the chains equally spaced from the center of gravity of the counterweight, means for connecting said chains to the car in a plane parallel to the plane of connection of the chains to the counterweight, with the chains equally spaced from the center of gravity of the car, a tensioning device for each chain at the bottom of the elevator hoistway, each tensioning device including a pair of grooved rubber tired compensating sheaves around which the chain passes and a frame for mounting said sheaves in horizontal alignment and spaced so that the chain hangs vertically from the car and counterweight, and means for guiding each tensioning device for vertical movement.

9. An elevator installation wherein the elevator car and its counterweight are suspended by hoisting roping, wherein a buffer is provided for the car positioned to act in the line of the center of gravity of the car and a buffer is provided for the counterweight positioned to act in the line of the center of gravity of the counterweight, and wherein apparatus is provided for compensating for the unbalanced weight of the hoisting roping, characterized by the fact that said compensating apparatus comprises a pair of chains extending from the car to the counterweight, said chains being connected to the car so as to be equally spaced one on each side of said car buffer and being connected to the counterweight so as to be equally spaced one on each side of said counterweight buffer, a tensioning device for each chain at the bottom of the elevator hoistway, each tensioning device including a pair of grooved neoprene tired compensating sheaves around which the chain passes and a frame for mounting said compensating sheaves in horizontal alignment and spaced so that the chain hangs vertically from the car and counterweight, and means for each frame for guiding it for vertical movement.

SAMUEL GUSTAVE MARGLES.

REFERENCES CITED The following references are of record in the file of this-patent:

UNITED STATES PATENTS Number Name Date 1,789,008 Lindquist Jan. 13, 1931 1,944,772 White Jan. 23, 1934 2,295,381 Bouton Sept. 8, 1942