US 3882968 A
An elevator system including an elevator car, counterweight, hoisting ropes interconnecting the elevator car and counterweight, and a drive for moving the car and counterweight in guided paths. A compensation system is provided which includes at least one metallic strip disposed between the elevator car and counterweight.
Description (OCR text may contain errors)
United States Patent 1191 Suozzo 1 May 13, 1975  ELEVATOR SYSTEM 1,944,772 1/1934 White 187/22 2.537,075 1/1951 Margles 187/22  Inventor? Hackensack 3,653,467 4/1972 Showalter 187/22  Assignee: Westinghouse Electric Corporation,
Pittsburgh, Pa. Primary Examiner-Evon C. Blunk Assislant Examiner-James L. Rowland  Filed June 1973 Attorney, Agent, or Firm-D. R. Lackey  Appl. No.: 366,234
 ABSTRACT  U.S. C1 187/22; 187/94 l d 51 Int. Cl. B66b 11/08 f Ystem "9 mg  Field of Search l87/2022, wegm ropes P h 816mm 187/26 38 94 and counterweight, and a drive for moving the car and counterweight in guided paths. A compensation sys- [561 iii? 11 15 25122:11:11:32,353?$32112? UNITED STATES PATENTS g 975,790 11/1910 Pearson 187/20 1,132,769 3/1915 Gale 187/22 5 Claims, 3 Drawing Figures r T" 64 I ELEVATOR SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention:
The invention relates in general to elevator systems, and more specifically to compensation systems for elevators.
2. Description of the Prior Art:
Elevator systems of the traction type conventionally employ compensation for the weight of the hoist ropes where the travel exceeds about 100 feet. This minimizes the unbalance between the car and counterweight as the car changes its position in the hoistway, providing more uniform torque requirements and assisting landing accuracy. Chains are conventionally used for compensation for elevators which operate at a travel rate of less than about 500 feet per minute, while stranded cables are used above a rate of 500 feet per minute. This changeover point between chains and roping for compensation is dictated primarily by acoustic noise, as chain compensation becomes objectionably noisy above about a 500 feet per minute travel rate.
While compensation in the form of a plurality of stranded cables is generally satisfactory, a problem may arise on windy days in high speed elevator systems which operate above about 1100 or 1200 feet per minute. When the wind is blowing outside a tall building, the difference in pressure between the bottom and top thereof can be quite substantial, resulting in wind velocities in the hatchway of an elevator system installed therein which may cause the compensating cables to sway. When this occurs, there is a possibility that the cables may become tangled and damaged.
SUMMARY OF THE INVENTION Briefly the present invention is a new and improved elevator system of the electric traction type, which utilizes a new and improved compensation system. Instead of using cables in the compensation system, as taught by the prior art, metallic strip is used to interconnect the bottoms of the elevator and counterweight. A single metallic strip formed of a suitable material, such as steel, may be selected to provide the total compensation required for a specific installation. Alternatively, a metallic strip of a suiutable standard size may be used, such as metallic strip having a width dimension of 4.5 inches and a thickness of 1/32 inch. A steel strip of these dimensions weighs about 0.57 pound per foot,
.which is approximately the same as the /8 inch diameter cable conventionally used for compensation. The desired compensation and weight per foot for each application is then achieved by selecting the required number of metallic strips and superposing or stacking them together.
A compensation system using metallic strip is not subject to tangling and damage due to wind in the hatchway as the strips will already be in preparranged contact with one another. Further, the metallic strip is lower in initial cost than the cables conventionally used, the metallic strip is easier to install in the field than the conventional cables, the metallic strip improves the riding quality as it eliminates vibration due to compensating cables, and the metallic strip has a longer useful operating life than the compensating cables of the prior art.
While a conventional compensator employing a heavy cast iron sheave may be used to guide and tension the metallic strip compensation, the metallic strip compensation permits a new and improved compensator to be used. Instead of a heavy cast iron sheave, a plurality of small rollers may be used to guide the metallic strip, with the frame on which the rollers are mounted being pivotally biased by means such as a spring to provide the desired tension in the strip. This arrangement substantially reduces the mass to be accelerated by the elevator drive machine, i.e., drive motor and direct current voltage source, and thus reduces drive requirements. The placement of the rollers on their support frame may be made adjustable to suit the distance from the car to the counterweight for each application, providing vertical compensation on the car and counterweight without a transverse component. This adjustment feature is not available with cast iron sheaves which are manufactured to only a few predetermined different diameters.
BRIEF DESCRIPTION OF THE DRAWINGS The invention may be better understood, and further advantages and uses thereof more readily apparent, when considered in view of the following detailed description of exemplary embodiments, taken with the accompanying drawings, in which:
FIG. 1 is a perspective view of an elevator system constructed according to the teachings of the invention; and
FIGS. 2 and 3 are side and end elevations, respectively, of an elevator system constructed according to another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and FIG. 1 in particular, there is shown an electric elevator system 10 of the traction type constructed according to the teachings of the invention. Elevator system 10 includes an elevator car 12 mounted for guided movement in a hoistway 14 of a building 15 having a plurality of floors to be served by the elevator car. An elevator drive motor 16, which may be disposed in a penthouse on the building 15, drives a traction sheave 18 via a drive shaft 20, and, if required, a deflection sheave 22 may be used in combination with the traction sheave 18 to obtain the required spacing between the elevator car 12 and a counterweight 24.
A plurality of hoisting ropes or cables 26 interconnect the elevator car 12 with the counterweight 24. The hoisting ropes 26 extend from the car 12 about the traction and idler sheaves l8 and 22, respectively, using the half wrap shown, or a full wrap, and then to the counterweight 24. The hoisting ropes 26 may be connected to the overhead channels of the elevator car and counterweight, if the roping is l to 1 as illustrated, or the hoisting roping may be reeved about a sheave carried by the car and/or counterweight, if either is roped 2 to l, in which event the hoisting roping would be dead ended above the travel paths of the elevator car and/or counterweight. As illustrated, the elevator car 12 includes a cab 28 mounted in a sling 30, with the cables 26 being connected to the top channel 32 of the sling 30.
'Conventionally, a plurality of compensating cables, such as /8 inch diameter wire ropes, would be connected to the bottom channel 34 of the car sling 30, they would run about a weighted compensator in the pit and then be fastened to the bottom channel of the counterweight 24. FIG. 1 illustrates a new and improved compensation system constructed according to the teachings of the invention which possesses many advantages over the prior art compensating roping arrangement, with a simpler, less costly, longer life structure.
More specifically, the compensation system shown in FIG. 1 includes a metallic strip 40 as the compensating means, instead of wire rope. Metallic strip is defined as a sheet of metal, such as steel, having a length dimension L much longer than its width dimension W, and with the width dimension W being many times its thickness dimension T. The strip 40 is connected to the car 12, such as to the bottom channel 34 of the sling 30, it runs about a weighted compensator 42 disposed in the pit, and is then connected to the bottom channel of the counterweight 24.
The thickness dimension I of the metallic strip 40 is selected on the basis of providing the necessary flexibility to run about the weighted compensator 42, and
- strength to withstand the tension applied to the strip 40 by the compensator. The width dimension W is se lected to provide a predetermined weight per foot of length, and may be selected to provide the total compensation required for the car, thus, requiring one strip; or, the weight per foot of a single strip may be selected to be less than the total compensation required, with a plurality of strips then being necessary to achieve the compensation required. For example, each strip may be selected to have the same weight per foot as the conventional /8 inch diameter wire rope used in prior art compensation systems, which for 1/32 inch thick steel strip would be about 4.5 to 5 inches. If the strip is selected to have the same weight per foot as the prior art compensation cable, the number of strips required for compensating a specific application would then be the same as the number of ropes which would have ordinarily been used for this application. However, it will be appreciated that the weight per foot of the strip 40 may be more or less than a inch diameter wire rope, requiring fewer or more metallic strips, respectively, than the number of ropes in a prior art compensation system for a similar application. Also, as hereinbefore stated, the metallic strip dimensions may be selected such that only a single strip need be used, if desired.
If a plurality of strips are used to achieve the required compensation, instead of the metallic strips being separated, as are the ropes in a conventional rope compensating system, they are superposed with the major surface of one metallic strip superposed directly over and contacting the major surface of the next adjacent strip. The plurality of superposed metallic strips thus function as a unit and there is no possibility of tangling due to wind in the hoistway on windy days. The steel strip required to provide a predetermined weight per foot is less costly than wire rope for the same weight per foot for compensation. Metallic strip may be selected which has a longer operating life than wire rope, as already proven by the long life achieved by the steel strip or tape used in the drive for the electromechanical floor selector used in elevator systems. The metallic strip is also easier to connect to the elevator car and counterweight, than a plurality of cables, reducing field labor costs, and it doesnt transmit the vibrations to the car 4 which a plurality of compensating cables do, improving the ride quality.
The compensator 42 shown in FIG. 1 is illustrated in combination withthe conventional weighted compensator which uses a heavy cast iron sheave 44 mounted for rotation in a frame 46. The frame 46 is allowed limited up and down guided movement to accommodate elastic and permanent stretch of the hoisting ropes. compensator 42 may be of the lock-down type, which permits limited upward movement of the frame 46 and when the limit is reached the frame 46 is locked to fixed guide rails 48 and 50, which rails also function to guide the vertical movement of the frame 46. The locking of the frame to the guide rails insures similar deceleration rates for the elevator car and counterweight when one of them is stopped rapidly, such as due to a safety or buffer stop. The locking means may be conventional, or the locking arrangement disclosed in copending application Ser. No. 347,285, filed Apr. 2, 1973, which is assigned to the same assignee as the present application, may be used.
Instead of using the conventional weighted compensator arrangement 42 shown in FIG. 1, the metallic strip compensating system disclosed herein permits a new and improved compensator to be used in combination therewith. The heavy cast iron compensator sheave 44 of the prior art must be accelerated and decelerated by the drive 16. The rating of the drive 16, and the rating of its source of direct current voltage must be selected accordingly. The cast iron sheave, by necessity, is constructed with only a few different diameters. Thus, it is not always possible to provide compensation on the car and/or counterweight without a lateral component, which thus increases the wear on the guide rollers and rails.
More specifically, FIGS. 2 and 3 are side and end elevational views, respectively, of an elevator system 60 which includes an elevator car 62 and counterweight 64, similar to the car and counterweight shown in FIG. 1, with metallic strip 66 interconnecting the bottoms of the car and counterweight via a new and improved compensator 70. The metallic strip 66 may be a single strip, or, as shown in the magnified insert 72, it may include a plurality of superposed strips, as desired.
The metallic strip compensation permits the compensator 70 to be constructed using a plurality of rollers 74 disposed to contact and guide the metallic strip 66 about a predetermined loop configuration in the pit of the hoistway. The mass of these relatively small diameter rollers is insignificant compared with the mass of the cast iron compensator sheave 44 shown in FIG. 1, enabling the rating of the drive 16 and its voltage source to be reduced accordingly. Further, the mounting locations of the rollers 74 may be easily adjusted for each elevator installation to provide vertical compensation for both the car and counterweight without a lateral force component. Rollers 74 may be provided with a tire of resilient material, such as polyurethane, which operates noiselessly against the inner major surface of metallic strip 66 without appreciable wear on either the strip or the tire.
The plurality of small diameter rollers 74 are mounted on a frame 76 which provides the desired tension in the strip 66, while accommodating permanent and elastic stretch in the hoisting cables, and limiting the upward movement of the frame to tie the car and counterweight together during a rapid stop of either.
Frame 76 includes a beam structure pivotally mounted at one end, such as provided by two spaced angle members 78 and 80, each of which includes first and second connected portions such as the first and second portions 82 and 84 of member 78 and the first and second portions 86 and 88 of member 80. The first portions 82 and 86 each have an opening disposed therein, which openings are aligned when the members 78 and 80 are disposed in spaced parallel relation with their first portions facing one another and their second portions extending perpendicularly away from one another. A bearing assembly 90 is mounted in the aligned openings, and a shaft member 92 is disposed through the bearing 90. Each end of shaft 92 may be fixed to a mounting plate member, such as mounting member 94,
and the mounting plate members are secured to the counterweight guide rails, such as the counterweight guide rail 96.
The rollers 74 are mounted on spaced plate members fixed to the facing surfaces of the first portions of members 78 and 80. Two spaced plate members may be used, or, as illustrated in FIGS. 2 and 3, two pairs 100 and 102 of spaced plate members may be used, with the dimension 104 between the adjacent pairs 100 and 102 being adjusted for each elevator during installation to achieve a dimension 103 between the ends of the loop which provides vertical compensation for both the car and counterweight without a lateral force component. Thus, the rollers and associated mounting plates may be manufactured in sub-assemblies and the spacing 104 set to the proper dimension by any suitable adjusting means, such as slotted openings in portions 82 and 86 of the angles and nut and bolt combination, indicated generally at 105, which are carried by the mounting plates, the bolts of which extend through the slotted openings. Thus, the loop dimension 103 may be readily adjusted.
Pair 102 of spaced plate members includes spaced mounting plates 106 and 108, and pair 102 includes spaced mounting plates, such as mounting plate 110 and a similar mounting plate spaced therefrom, which is not visible in FIGS. 2 and 3. The two pairs of spaced mounting plates are identical, except one pair is reversed or flipped over compared with the other pair. The shafts upon which the rollers 74 are mounted, such as shaft 112, are preferably fixed to the spaced mounting plates, and the rollers journaled in bearings for rotation on the shafts; or, the rollers may be fixed to their associated shafts and the shafts journaled in bearings for rotation in the spaced mounting plates.
In addition to rollers 74 which direct the metallic strip 66 about a loop configuration in the pit, guide roller assemblies 116 and 118 are disposed to contact the edges of the strips 66 to guide the strip as it enters and leaves the compensator 70. For example, guide roller assembly 116 may include an angular mounting bracket or member 120 which is fixed to the upper surfaces of the spaced mounting plates members 106 and 108. The angular member 120 supports an arm 122 which is pivotally mounted thereon. The outer ends of arm 122 include guide rollers 124 and 126 each having a suitable groove on its periphery for receiving an edge of the metallic strip 66. The rotatable arm 122 is biased in a clockwise direction as viewed in FIG. 3, to force the guide rollers 124 and 126 against the edges of strip 66. The guide rollers 124 and 126 are journaled for rotation to rotate with the strip 66 as it moves about the compensator The guide roller assembly 118 is of similar construction.
The tension and lock-down feature for compensator 70 is provided by upstanding cylindrical-posts 130 and 132, spiral compression spring members 1 34 and 136, an upper spring seat 138, and nuts 140 and 142. The cylindrical posts l30 and 132 are fixed to the floor of the pit and they extend *vertically upward through openings disposed inangles 78 and 80, respectively. These openings are large enough to permit the member 78 and to pivot as a unit about shaft 92 through a predetermined angle. Springs 134 and 136 are telescoped over the upstanding ends'of posts and 132, respectively, with the top surfaces of the second portions 84 and 88 of members 78 and 80, respectively, functioning as lower spring seats. The upper spring seat 138 has openings therein for receiving the posts 130 and 132, and it is placed in position thereon to contact the upper ends of the springs 134 and 136. The nuts 140 and 142 are then disposed on suitably threaded ends of the posts to force the spring seat 138 downwardly to compress the springs 134 and 136. This biases the compensator 70 about shaft 92 in a clockwise direction, as viewed in FIG. 2, providing the desired tension in the strip 66. The springs 134 and 136 enable the compensator 70 to move up and down with changes in the length of the hoisting ropes, but it limits upward travel of the compensator 70 to the point where the springs 134 and 136 pipe, which then locks the car and counterweight together to achieve a similar deceleration rate.
In summary, there has been disclosed a new and improved elevator system which precludes tangling of the compensator ropes used in the prior art by eliminating the compensating ropes and using compensation in the form of one or more metallic strips. In addition, the new compensating system is less costly, easier to install, produces less vibration in the car, and has a longer operating life than compensating systems of the prior art.
The metallic strip compensation also enables a new and improved compensator to be used for tensioning and guiding the metallic strip, as well as locking down the compensator during a rapid stop of either the car or counterweight. The metallic strip compensation permits a series of small spaced rollers to be used for guiding the metallic strip about a loop in the pit, reducing the mass which must be accelerated and decelerated, compared with the prior art cast iron compensator sheave, and making it possible to easily achieve the desired spacing of the ends of the loop in the pit to accommodate the car and counterweight spacing for each elevator installation. Thus, vertical compensation may easily be provided for both the car and counterweight without a side or lateral component of force.
I claim as my invention:
1. An elevator system comprising:
an elevator car;
motive means mounted above said car and counterweight,
hoisting roping disposed in frictional contact with said motive means and interconnecting said car and counterweight; said car and counterweight being moved vertically responsive to said motive means, with said hoisting roping adding weight to said car and counterweight responsive to their relative positions;
compensating means, said compensating means including at least one metallic strip extending from said car to said counterweight in a loop disposed below said car and counterweight, said at least one metallic strip being dimensioned to provide a predetermined weight per unit length selected to substantially reduce the weight unbalance between said car and counterweight caused by said hoisting roping as the relative positions of said car and counterweight change,
tensioning means disposed below-the elevator car and counterweight for tensioning and guiding the at least one metallic loop, said tensioning means including support means,
a plurality of first rollers, means mounting said first rollers in spaced relation on said support means, with the at least one metallic strip disposed to contact said first rollers,
bias means for biasing said support means to tension the at least one metallic strip,
and a plurality of second rollers disposed to contact the edges of the at least one metallic strip and guide the at least one metallic strip as it enters and leaves the first rollers.
2. The elevator system of claim 1 wherein the compensating means includes a plurality of superposed metallic strips.
3.. The elevator system of claim 1 wherein the support means is pivotally mounted for rotation in a vertical plane, and the bias means biases the support means in a downward direction.
4. The elevator system of claim 1 wherein the tensioning means includes a plurality of rollers mounted on support means such that the rollers contact and guide the metallic strip in a loop configuration.
5. An elevator system comprising: an elevator car; a counterweight; motive means for said car and counterweight including hoisting roping interconnecting said car and counterweight;
compensating means, said compensating means including at least one metallic strip extending from said car to said counterweight in a loop disposed below said car and counterweight, and
tensioning means disposed below the elevator car and counterweight for tensioning and guiding the at least one metallic loop, said tensioning means including support means, means pivotally mounting said support means for rotation in a vertical plane, a plurality of first rollers, means mounting said first rollers in spaced relation on said support means, with the at least one metallic strip disposed to contact said first rollers, and bias means for biasing said support means in a downward direction to tension the at least one metallic strip, said bias means including a spring member disposed to allow a predetermined pivotal movement of the support means, and to provide a stop beyond which the support means cannot pivot upwardly, to tie the elevator car and counterweight together to achieve similar rates of deceleration during a rapid stop of either the elevator car or counterweight.