Patent Application
20080142311
This invention generally relates to elevator systems. More particularly, this invention relates to a pit buffer assembly for use in an elevator system.
Elevator systems include a variety of devices for controlling the movement or position of an elevator car, counterweight or both. One such device is known as a pit buffer and provides a cushion or energy-absorbing effect at the bottom of a hoistway under certain conditions. Various pit buffers are known.
One shortcoming of pit buffer arrangements is that they take up valuable space. A pit buffer must be of sufficient size to provide the necessary energy-absorbing capacity. Buffers must have a sufficient height to provide a sufficient stroke to achieve the energy-absorbing capacity needed to provide adequate cushion at the bottom of a hoistway. The requirement of sufficient buffer size typically requires a deeper pit at the bottom of a hoistway, for example. This can result in additional building expense, which is undesirable.
It is desirable to provide a pit buffer arrangement that enhances the economies associated with having adequate cushioning or energy-absorbing capacity at the bottom of a hoistway. This invention provides such an arrangement.
An example buffer assembly that is useful in a pit of an elevator system includes a plurality of buffers spaced from each other such that a vertically moving mass is received at least partially between the buffers before the buffers interact with the mass.
In one example, the buffers each have a height relative to a floor surface in a pit and the mass moves closer to the floor surface than the height before the buffers interact with the mass. In one example, the moving mass is a counterweight that includes a strike member that contacts the buffers and the strike member is positioned near a top of the counterweight.
In one example, the buffers are aligned with guide rails that guide vertical movement of the mass such that the buffers are between the guide rails and at least a portion of the mass is received between the buffers.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.
The buffer assembly 30 minimizes occupied space by allowing at least a portion of the counterweight 24 to move below an uppermost portion of the buffer assembly before the buffer assembly interacts with the counterweight.
In the illustrated example, the buffers 32 have a lower portion 34 that is secured in a fixed position relative to a surface 36 near the bottom 28 of the hoistway 26. In one example, the surface 36 is a bottom surface in a pit. An opposite end 38 of the buffers 32 is distal from the surface 36. The ends 38 of the buffers 32 define a height h of the buffers 32 relative to the surface 36.
In the illustrated example, the buffers 32 comprise a first stationary portion 40 and a second, moveable portion 42. The second portions 42 move relative to the first portions 40 in a known manner responsive to contact with the counterweight 24. In one example, the buffers 32 comprise springs. In one example, each buffer 32 includes a coil spring that biases the distal end 38 toward the uppermost position shown in
In
In the illustrated example, the strike member 60 provides a mounting surface for guides 64 that guide movement of the counterweight 24 along guide rails 66 in a known manner. The guides 64 are schematically shown and may comprise any known guide for such a purpose.
In another example, the strike member 60 is positioned more centrally on the counterweight 24.
The example arrangement shows how a plurality of buffers spaced apart sufficient to allow a portion of a vertically moving mass (i.e., a counterweight) to be received between the buffers accommodates a greater range of motion of the moving mass while still using buffers having adequate stroke to provide the necessary energy-absorbing characteristics within a given elevator system.
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/US05/04271 | 2/9/2005 | WO | 00 | 8/2/2007 |
