KR100920879B1 - Compensation in an elevator system having multiple cars within a single hoistway - Google Patents

Abstract

The elevator system 20 includes a plurality of elevator cars 22, 32 in the hoistway 28. The first correction member 40 is connected with the first counterweight 24. The second correction member 50 is connected with the second elevator car 32 of the elevator cars. Each compensating member has one end moving with the connected elevator system element and opposing ends 44 and 54 fixed in a fixed position in the hoistway. In one example, the correction member has a linear density that is approximately four times the linear density of the corresponding load bearing member.

Elevator, compensating member, rope, chain, load bearing member, counterweight

Description

Compensation in an elevator system with multiple cars in a single hoistway {COMPENSATION IN AN ELEVATOR SYSTEM HAVING MULTIPLE CARS WITHIN A SINGLE HOISTWAY}

The present invention relates generally to elevator systems. In particular, the present invention relates to calibration in an elevator system having one or more cars in a hoistway.

Elevator systems are well known. Various structures are used depending on the needs of a particular situation. In many skyscrapers, corrections are used to correct for load imbalances that occur, for example, when the elevator car is at its highest possible position. Conventional correction devices include ropes or chains and corresponding counterweights suspended below the elevator. Opposite ends of the rope or chain are secured to the car and counterweight respectively.

Known calibration devices have proven useful for many elevator systems, but there are difficulties when introducing one or more elevator cars into the hoistway. When one elevator car is positioned above another in a hoistway, conventional compensators for higher elevator cars hinder the movement or operation of the lower cars. One proposal is disclosed in US Pat. No. 5,584,364. The drawback of such a device is the inclusion of a special vibration damper to accommodate the correction rope. Another calibration device is required.

The present invention addresses that need by providing a correction to an elevator system having a plurality of cars in a hoistway.

An exemplary elevator system includes a first elevator car that is supported for vertical movement in the hoistway. The first counterweight is engaged with the first elevator car by the first load bearing member. The second elevator car is positioned below the first elevator car and is supported for vertical movement in the same hoistway. The second counterweight is engaged with the second elevator car by the second load bearing member. The second counterweight is positioned above the first counterweight. The first correction member is connected with the first counterweight. The second correction member is connected with the second elevator car.

In one example, the first compensating member has a first end that moves with the first counterweight and a second end that is fixed at a fixed position in the hoistway. The second correction member has a first end that moves with the second elevator car and a second end that is fixed at a fixed position in the hoistway.

In one example with a 1: 1 roping ratio, the compensating member is selected to have a mass per unit length that is approximately four times greater than the mass per unit length of the load bearing member. In another example with a 2: 1 roping ratio, the mass per unit length of the correction member is approximately eight times the mass per unit length of the load bearing member.

In one example, the total mass of the correction member is approximately twice the total mass of the corresponding load bearing member.

By using the correction member in the disclosed manner, it is possible to provide correction in an elevator system having a plurality of cars in a single hoistway.

Various features and advantages of the invention will generally be apparent to those skilled in the art from the following detailed description of the preferred embodiments. The drawings with the detailed description can be briefly described as follows.

1 schematically shows a selected portion of an elevator system comprising a correction member arranged according to an embodiment of the invention.

1 schematically shows selected portions of an elevator system 20. The first elevator car 22 is coupled to the first counterweight 24 by the load bearing member 26. It is known that a plurality of ropes or belts arranged next to each other support the car and counterweight. The term "load support member" is used herein to refer to, for example, one or more ropes or belts. The machine (not shown) causes the selected movement of elevator car 22 and counterweight 24 in hoistway 28 in a known manner.

The system shown includes a second elevator car 32 connected with a second counterweight 34 by a second load bearing member 36. The second elevator car 32 is positioned below the first elevator car 22. The first counterweight 24 is positioned below the second counterweight 34. In one example, the elevator cars share a common guide rail, and the counterweights share a common guide rail.

Since the elevator car is positioned on the floor, a conventional calibration device will not work for both elevator cars and counterweights. The example device shown has a first correction member 40 connected with a first counterweight 24. In one example, one end 42 of the correction member 40 is fixed to an appropriate portion of the first counterweight 24 such that the end 42 moves with the first counterweight 24. The opposite end 44 of the correction member 40 is fixed at a fixed position in the hoistway 28.

In one example, the correction member 40 comprises a chain. In another example, the correction member 40 includes a rope. Known materials for manufacturing the correction member may be used for the first correction member 40.

The second correction member 50 is connected with the second elevator car 32. As schematically shown, the first end 52 is secured to an appropriate portion of the second elevator car 32 for movement with the car. The opposite end 54 of the second correction member 50 is fixed at the fixed position in the hoistway 28. As the second elevator car 32 moves downwards, for example, the mass of the correction member 50 is transferred to the second counterweight 34 as occurs in a conventional correction device, instead of building (i.e., , The wall of the hoistway is delivered. The second correction member 50 may be made of the same material selected for the first correction member 40, for example.

Fixing one end of each correction member in the hoistway 28 in a fixed position ensures that the elevator system elements (ie the car and counterweight) are at the highest position 62 or the lowest position 60 in the hoistway 28. It is possible to correct the load state when it is present. Rather than suspending the correction member between the car and the corresponding counterweight, fixing one end of each correction member in the hoistway 28 in a fixed position, otherwise the second correction member 40, for example, causes the first elevator car. Interference that may occur if suspended between 22 and the first counterweight 24 is prevented.

The depicted structure of the correction member has some similarities to the way conventional electrically conductive moving cables were installed in elevator systems. A significant difference between the correction member shown and such a mobile cable is that the correction member is much heavier than the mobile cable. The moving cable does not have enough mass to provide correction to the load bearing member. In one example, the mass of the correction member 50 is approximately twice the collective total mass of the corresponding load bearing member 36. On the other hand, the moving cable has a total mass smaller than the total mass of the load bearing member.

In one example where the load bearing member has a 1: 1 roping ratio, a 100% correction corresponding to balancing the force between the car and the counterweight regardless of the height of the element results in a mass or linear density per unit length of the corresponding load bearing member. Selecting mass or linear density per unit length of the calibration member to be approximately four times. Rather than individual ones, collective linear densities of a plurality of ropes or belts that serve as corresponding load bearing members are considered. Referring to the example and considering the second correction member 50, the second elevator car 32 and the second counterweight 34 as an example, the total tension on the counterweight side of the machine (not shown) is as follows. Can be expressed.

Tcwt = Wcwt + H * Dsusp (1)

Where Tcwt is the tension on the counterweight side of the machine (in kilograms), Wcwt is the weight of the counterweight (in kilograms), H is the height of the car (in meters) from the lowest landing, and Dsusp is the load bearing member ( 36), in kilograms per meter.

On the car side of the machine, the tension is equal to the weight of the car 32 plus the weight of the correction member 50 and the weight of the load bearing member 36, which can be expressed as follows.

Tcar = Wcar + (R-H) * Dsusp + H / 2 * Dcomp (2)

Where Tcar is the tension on the car side of the machine (in kilograms), Wcar is the weight of the car (in kilograms), R is the vertical rise (in meters) of the elevator, and Dcomp is the compensating member 50 The density of in kilograms per meter.

The tension difference between the car side and the counterweight side can be expressed as follows.

Tcwt-Tcar = Wcwt + H * Dsusp- (Wcar + (R-H) * Dsusp + H / 2 * Dcomp) (3)

It can be expressed as follows.

Tcwt-Tcar = Wcwt-Wcar-R * Dsusp + H * (Dsusp + Dsusp-1 / 2Dcomp) (4)

The tension difference will be independent of the position of the car 32 in the hoistway 28 when the (Dsusp + Dsusp-1 / 2Dcomp) term in equation (4) is equal to zero (ie, 100% correction). Accordingly, 1 / 2Dcomp = 2Dsusp and Dcomp = 4 * Dsusp.

In this example, 100% correction is obtained by selecting the linear density of the correction member 50 to be approximately four times the linear density of the load bearing member 36. Different percentages are possible by choosing different linear densities. In many cases a 90% calibration is desirable. Those skilled in the art having the benefit of this description will be able to select appropriate values to meet their specific needs.

Of course, the same analysis is applied to the first elevator car 22 and the first counterweight 24 to determine the desired linear density of the first correction member 40.

In another example involving a 2: 1 roping ratio, the correction member linear density is approximately eight times the collective linear density of the corresponding load bearing member.

In another embodiment, the correction members 40, 50 have a length that is approximately one half of the length of the corresponding load bearing member. Using the 100% correction analysis described above, an illustrative example includes a correction member having a mass that is twice the mass of the corresponding load bearing member.

The disclosed calibration technique makes it possible to provide calibration to high-rise applications of elevator systems having one or more elevator cars in the hoistway.

The above description is illustrative rather than limiting in nature. Modifications and variations of the disclosed embodiments that are not necessarily departing from the spirit of the invention may be apparent to those skilled in the art. The scope of legal protection given to this invention can only be determined by reviewing the following claims.

Claims (16)

A first elevator car supported for vertical movement in the hoistway, With the first counterweight, A first load bearing member coupling the first elevator car and the first counterweight; A second elevator car positioned below the first elevator car and supported for vertical movement in the hoistway; A second counterweight positioned over the first counterweight, A second load bearing member coupling the second elevator car and the second counterweight; A correction member for correcting the load state having a first end connected with one of the first counterweight or the second elevator car and having a first end moving with the connected counterweight or elevator car and fixed at a fixed position in the hoistway; Including elevator system. The elevator system of claim 1, wherein the correction member is connected with the first counterweight. 3. An elevator system according to claim 2 comprising a second correction member having a first end moving with the second elevator car and a second end fixed in a fixed position in the hoistway. 2. The device of claim 1, further comprising: a second end connected with the other of the second elevator car or the first counterweight, the first end moving with the connected elevator car or counterweight and a second end fixed in a fixed position in the hoistway. Elevator system comprising a correction member. The elevator system of claim 4, wherein the counterweight is positioned at the selected side of the elevator car and the second end of the second correction member is positioned at the other side of the second elevator car. The elevator system of claim 1, wherein the first load bearing member has a mass per unit length and the correction member has a mass per unit length that is one of four or eight times the mass per unit length of the first load bearing member. The elevator system of claim 6, wherein the correction member has a total mass that is twice the total mass of the first load bearing member. The elevator system of claim 1, wherein the second load bearing member has a mass per unit length and the correction member has a mass per unit length that is one of four or eight times the mass per unit length of the second load bearing member. The elevator system of claim 8, wherein the correction member has a total mass that is twice the total mass of the second load bearing member. The elevator system of claim 1, wherein the correction member has a total mass that is twice the total mass of the connected load bearing member. The elevator system of claim 1, wherein the correction member comprises at least one of a rope or a chain. A method of correcting load imbalance in an elevator system having at least two elevator cars and at least two counterweights on the same hoistway, Securing the first end of the correction member to either the low counterweight of the counterweight or the low elevator car of the elevator car, Securing the second end of the correction member in a fixed position in the hoistway. 13. The method of claim 12, further comprising: fixing one end of the second correction member to the other of the low elevator car of the elevator car or the low counterweight of the counterweight, and fixing the opposite end of the second correction member to the fixed position in the hoistway. Method comprising the steps of: 13. The method of claim 12, wherein the load bearing member combines the corresponding elevator car and the counterweight and selects the mass per unit length of the correction member to be four times the mass per unit length of the corresponding load bearing member. 13. The method of claim 12, wherein the load bearing member combines the corresponding elevator car and the counterweight and selects the mass per unit length of the correction member to be eight times the mass per unit length of the corresponding load bearing member. 13. The method of claim 12, wherein the load bearing member comprises combining the corresponding elevator car and the counterweight and selecting the total mass of the correction member to be twice the total mass of the corresponding load bearing member.

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