Patent Application
20130277152
Elevator systems include a machine for moving the elevator car to provide elevator service. In traction-based systems a roping arrangement suspends the weight of the elevator car and a counterweight. Traction between the roping arrangement and a traction sheave that is moved by the elevator machine provides the ability to move the elevator car as desired.
When the rise of an elevator system is sufficiently large, the longer roping members introduce the possibility for an elevator car to bounce or oscillate as a result of a change in load while the elevator car is at a landing. In some cases, elevator passengers may perceive a bounciness of the elevator car, which is undesirable.
There are various known devices for holding an elevator car fixed at a landing. Mechanical stops have been introduced into elevator systems to engage a stationary structure to hold the elevator car rigidly in place. Brake devices have been proposed that engage a guide rail or other stationary structure within the hoistway to prevent movement of the elevator car. Such devices may however require additional maintenance and service when a brake or mechanical stop does not release from a locked position when necessary. Additionally, many such devices introduce noise. There is a need for an improved way of stabilizing an elevator car when it is stopped.
An exemplary device for use in an elevator system includes at least one friction member that is selectively moveable into a damping position in which the friction member is useful to damp movement of an elevator car associated with the device. A solenoid actuator has an armature that is situated for vertical movement. The armature moves upward when the solenoid is energized to move the friction member into the damping position. The armature mass urges the armature in a downward vertical direction causing the friction member to move out of the damping position when the solenoid is not energized.
An exemplary elevator system includes an elevator car. A plurality of load bearing members suspends the elevator car. At least one guide rail is situated to guide vertical movement of the elevator car. A damping device is supported on the elevator car. The damping device includes at least one friction member that is selectively moveable into a damping position in which the friction member engages the guide rail to damp movement of the elevator car. A solenoid actuator has an armature that is situated for vertical movement. The armature moves upward when the solenoid is energized to move the friction member into the damping position. The armature mass urges the armature in a downward vertical direction causing the friction member to move out of the damping position when the solenoid is not energized.
An exemplary method of controlling the position of an elevator car includes stopping the elevator car in a desired position. Energizing a solenoid causes upward movement of an armature of the solenoid which causes a friction member to move into a damping position in which the friction member engages a guide rail associated with the elevator car. Deenergizing the solenoid allows gravity to urge the armature downward and the friction member out of the damping position before moving the elevator car from the desired position.
The various features and advantages of a disclosed example will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.
An elevator machine 30 includes a motor 32 and a brake 34 to control movement of a traction sheave 36. Traction between the load bearing members 26 and the traction sheave 36 provides control over the movement and position of the elevator car 22. For example, the motor 32 causes the traction sheave 36 to rotate which causes movement of the load bearing members 26 to achieve a desired movement of the elevator car 22 along guide rails 38.
The brake 34 is used to prevent rotation of the traction sheave 36 for stopping the elevator car 22 at a desired vertical position along the guide rails 38. In one example, the load bearing members 26 have a construction and a length that introduces the possibility for the elevator car 22 to bounce or oscillate vertically relative to a desired parking position. The example of
The example damping device 40 includes a unique arrangement of components that provides for smooth, quiet and reliable operation of the damping device 40.
The solenoid housing 52 is situated so that an armature 54 (shown in
In one example, the damping position in which the friction members 44 engage the surface 64 introduces enough friction to damp bouncing or oscillation of the elevator car 22. The level of engagement between the friction members 44 and the surface 64, however, is not sufficient to be a braking or holding force that holds the elevator car 22 rigidly in position relative to the guide rails 38. This example includes introducing only a sufficient friction force for damping undesired movement of the elevator car 22.
One feature of the example links 58 and connector 56 is that different lengths or masses for those components provide a different movement of the arms 46. The size of the connector 56 and links 58 may be selected to provide a desired mechanical advantage so that the force associated with frictionally engaging the guide rail 38 by the friction members 44 has a desired magnitude given the operating characteristics of the selected solenoid 50. Given this description, those skilled in the art will realize how to configure the linkage arrangement between the solenoid armature and the arms 46 to meet the needs of their particular situation.
When it is necessary to move the elevator car again, the solenoid 50 is deenergized. The mass of the armature 54 is urged downward (see
The illustrated example includes utilizing a vertically oriented solenoid armature and gravity for resetting the damping device 40 into a non-engagement position. This provides more reliable operation compared to devices in which a solenoid is positioned so that the armature moves horizontally to introduce a braking force to prevent movement of an elevator car, for example. The vertically oriented solenoid of this example ensures that the damping device 40 will not interfere with desired movement of the elevator car 22 whenever the solenoid is deenergized. Additionally, relying upon gravity for resetting the damping device 40 overcomes any binding effect that may result from engagement between the friction members 44 and the surface 64 on the guide rail 38.
Another feature of the illustrated example can be appreciated from
Another feature of the illustrated example is that the solenoid 50 is configured to provide quiet operation. In one example, the solenoid 50 has a noise reducing feature to reduce or eliminate noise associated with movement of the armature 54 during energization or deenergization of the solenoid 50.
The noise reducing members 74 and 76 establish air cushions within the housing 52 so that movement of the armature (e.g., plunger 72 and rod 54) is pneumatically damped. This reduces or eliminates noise associated with such movement and provides quiet damping device operation.
A second plot 90 shows the oscillations resulting from the same change in load at the same landing with a damper device 40 energized. The oscillations are significantly damped and essentially eliminated in about one second. Additionally, the damped condition prevents further changes in load from introducing further oscillations. During the oscillations at 80, an additional change in load or introduced acceleration on the car will contribute to the oscillations and cause them to increase in magnitude. Accordingly, the disclosed damper device 40 significantly improves car stability.
Another feature of the illustrated example is that it provides a fast response time for activating or deactivating the damping device 40. Transitions between an engaged or disengaged position can be completed quickly in a manner that does not introduce any noticeable delays into the elevator system operation. The illustrated example allows for maximizing speed and minimizing noise because it provides a low-noise damping device that does not interfere with passenger satisfaction with elevator service.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2010/061809 | 12/22/2010 | WO | 00 | 6/19/2013 |
