ELEVATOR BRAKE ASSEMBLY

An elevator brake assembly including an asymmetrical brake comprising at least three brake segments, a brake activating device operably coupled to the asymmetrical brake, the brake activating device comprising a first activation element and a second activation element, wherein the first activation element is configured to activate one of the at least three brake segments, and the second activation element is configured to activate the remaining of the at least three brake segments.

TECHNICAL FIELD OF THE DISCLOSED EMBODIMENTS

The presently disclosed embodiments generally relate to elevator systems and more specifically, an elevator brake assembly.

BACKGROUND OF THE DISCLOSED EMBODIMENTS

Elevators are presently provided with a plurality of braking devices which are designed for use in normal operation of the elevator, as for example to hold the elevator car in place when it stops at a landing; and which are designed for use in emergency situations such as stopping the elevator car and/or counterweight from rapidly descending into the hoistway pit.

Electromechanical brakes are generally designed and installed in two sets controlled by a single coil. Each set of brakes has equal torque and are applied simultaneously. For multiple segment brake assemblies (i.e. more than two brake sets), multiple brake coils are required to provide flexibility in the timing of the application of the brakes. As a result, the increased number of coils increases the cost of the elevator system. There is therefore a need for a more cost effective solution for multiple segment brake assemblies.

SUMMARY OF THE DISCLOSED EMBODIMENTS

In one aspect an elevator brake assembly is provided. The elevator brake assembly includes an asymmetrical brake including at least three brake segments, and a brake activating device operably coupled to the asymmetrical brake. The brake activating device includes a first activation element and a second activation element, wherein the first activation element is configured to activate one of the at least three brake segments, and the second activation element is configured to activate the remaining of the at least three brake segments. In any embodiment, the first activation element comprises a first coil and the second activation element includes a second coil.

In one embodiment the at least three brake segments are located adjacent to one another and circumferentially disposed around a plate. In another embodiment, the at least three brake segments include a first brake segment and a second brake segment circumferentially disposed around a third brake segment. In another embodiment, the at least three brake segments include a first brake segment positioned adjacent to a second brake segment; the first activation element is positioned adjacent to the first brake segment and the second brake segment, a third brake segment positioned adjacent to the first activation element and the second activation element is positioned adjacent to the third brake segment.

In any embodiment, the at least three brake segments further include a plurality of brake applying portions, wherein a respective one of the plurality of brake applying portions is disposed on each of the at least three brake segments. In an embodiment, the plurality of brake applying portions includes a plurality of shoes.

In one aspect, an elevator system is provided. The elevator system includes a machine housing, a rotatable output shaft mounted in said machine housing, a sheave mounted on said output shaft and rotatable therewith, and a brake assembly configured for braking said output shaft. The brake assembly includes an asymmetrical brake including at least three brake segments, and a brake activating device operably coupled to the asymmetrical brake, the brake activating device comprising a first activation element and a second activation element, wherein the first activation element is configured to activate one of the at least three brake segments, and the second activation element is configured to activate the remaining of the at least three brake segments. In an embodiment, the first activation element includes a first coil and the second activation element includes a second coil.

In an embodiment, the asymmetrical brake includes at least three brake segments located adjacent to one another and circumferentially disposed around a plate. In another embodiment, the asymmetrical brake includes a first brake segment and a second brake segment circumferentially disposed around a third brake segment. In another embodiment, the asymmetrical brake includes a first brake segment positioned adjacent to a second brake segment; the first activation element is positioned adjacent to the first brake segment and the second brake segment, a third brake segment positioned adjacent to the first activation element, and the second activation element is positioned adjacent to the third brake segment.

In any embodiment of the elevator system, the asymmetrical brake further includes a plurality of brake applying portions, wherein a respective one of the plurality of brake applying portions is disposed on each of the at least three brake segments. In an embodiment, the plurality of brake applying portions includes a plurality of shoes

Other embodiments are also disclosed.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

FIG. 1illustrates an elevator system, generally indicated at10. The elevator system10includes an elevator car12and counterweight14. A roping arrangement16(e.g., round ropes or flat belts) supports the weight of the elevator car12and counterweight14in a known manner. An elevator machine18includes a motor20associated with a traction sheave22.

FIG. 2illustrates a cross-sectional view of selected portions of the example elevator machine18. The motor20selectively drives a shaft24in response to signals from a controller26. Rotation of the shaft24moves traction sheaves22, which move ropes or belts to move the elevator car12and counterweight14in the hoistway as known. The example shaft24includes a disk28within a brake assembly30. The brake assembly30selectively applies a braking force to the disk28to resist rotation of the shaft24. In one example, the controller26commands the brake assembly30to apply a braking force to hold the elevator car12at a selected building landing (not shown) or to slow the movement of the elevator car12.

FIGS. 3-5illustrate different embodiments of the brake assembly30. The brake assembly30comprises an asymmetrical brake32including at least three brake segments. Only three brake segments,34,36, and38are shown in the embodiments; however, it will be appreciated that more than three brake segments may be used in accordance with the present disclosure. In any embodiment, each of the at least three brake segments include a brake applying portion40disposed thereon. In any embodiment, the brake applying portion40may include a brake shoe to name one non-limiting example.

The brake assembly30further includes a brake activating device42operably coupled to the asymmetric brake32. The brake activating device42includes a first activation element, such as a first coil44configured to activate one of the at least three brake segments (e.g. a brake segment38), and a second activation element, such as a second coil46configured to activate the remaining of the at least three brake segments (e.g. brake segments34and36).

The brake assembly30, as shown in the embodiment ofFIG. 3, may include an asymmetrical brake32including at least three brake segments34,36, and38located adjacent to one another and circumferentially disposed around a segmented plate. The brake assembly30, as shown in the embodiment ofFIG. 4, may include brake segments34and36circumferentially disposed around brake segment38. It will be appreciated that brake segments34,36need not be concentric to the brake segment38. The brake assembly30, as shown in the embodiment ofFIG. 5, may be a stacked brake configuration, wherein the brake segments34and36are located adjacent to the disk28. The second activation element46is located adjacent to brake segments34and36. Brake segment38is located adjacent to the second activation element46, and the first activation element44is located adjacent to the brake segment38.

During operation, the brake activating device42may independently de-energize the first activation element44and/or second activation element46to increase flexibility of the timing and braking torque applied to the shaft24or disk28. For example, in situations where the elevator car12is empty and moving in a downward direction, the brake activating device42may de-energize the first activation element44and the second activation element46to apply the at least three brake segments34,36, and38.

In a situation where the elevator car12is empty and moving in an upward direction, the brake activating device42may sequentially activate the asymmetric brake30by first de-energizing the second activation element coil46to apply all but one of the brake segments (e.g. brake segments34and36); then, after a time delay, de-energizing the first activation element44to apply one of the brake segments (e.g. brake segment38).

In a situation where the elevator car12is balanced and moving in either the up or down direction, the brake activating device42may sequentially activate the asymmetric brake30by first de-energizing the second coil46to apply the third brake segment38; then, after a time delay, de-energizing first coil44to apply the first brake segment34and second brake segment34.

It will be appreciated that the brake assembly30includes an asymmetrical brake32including at least three brake segments operably coupled to a brake activating device configured to independently operate the at least three brake segments to selectively apply different brake torques to the shaft24or disk28to improve stopping performance.