Elevator – industrial lift truck – or stationary lift for vehicle – Having specific load support drive-means or its control – Includes linking support cable in drive-means
Patent
1998-12-31
2000-11-21
Kramer, Dean J.
Elevator, industrial lift truck, or stationary lift for vehicle
Having specific load support drive-means or its control
Includes linking support cable in drive-means
187272, 187401, B66B 1104
Patent
active
061489611
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a drive device for an elevator or a similar installation.
More precisely, the invention relates to means for controlling the up and down movement of an elevator cage or the like in the elevator shaft in which it is installed.
In the present patent application, the term "elevator cage or the like" covers not only conventional elevators for the able bodied, but also hoists and lifts for goods or for the handicapped.
It is well known that there are two major techniques in existence for implementing the drive device that controls the up and down movements of an elevator cage, which devices are either electrical or hydraulic. The present invention relates solely to the field of hydraulically controlled elevators. Naturally, the term "hydraulic" control covers means that are powered by a liquid that is not necessarily water.
In drive systems for elevators of the hydraulic type, it is conventional to have an actuator whose stroke serves to control the displacements of the elevator. The actuator cylinder is fixed in the elevator shaft and the end of the actuator rod is secured to the frame which is itself secured to the elevator cage.
It will be understood that controlling the displacement of an elevator cage in this way requires an actuator to be implemented whose stroke is very large since it is naturally equal to the displacement amplitude of the elevator cage. This makes it necessary in particular to use actuators having telescopic rods which become very difficult to make once the stroke of the elevator is large.
Nevertheless, it should be emphasized that hydraulic devices for moving an elevator cage present numerous advantages over electrically controlled devices. In particular, the cost of hydraulic drive devices for large loads is small compared with the cost of electric motor devices, and in addition such control devices are much quieter than electric motor devices. This advantage of quietness becomes particularly important when installing elevators in buildings.
SUMMARY OF THE INVENTION
An object of the present invention is thus to provide a hydraulic type drive device for an elevator that makes it possible to develop a large stroke for the elevator while nevertheless being simpler in structure than conventional hydraulic means for controlling displacement.
To achieve this object, the invention provides a drive device for an elevator of the type comprising a cage secured to a frame co-operating with vertical guide means, the drive device being characterized in that it comprises: co-operating with the vertical guide means; actuator cylinder being secured to one of the elements constituted by the frame and the cross-member, the end of the actuator rod being secured to the other of said two elements; respective horizontal axes secured respectively to the moving cross-member and to the frame; block system, a first end of said cable being secured to the top end of the elevator shaft and the other end of the cable being secured to one of said two elements; and actuator cylinder.
It will be understood that the stroke of the actuator serves merely to move apart the frame proper and the horizontal cross-member which is free to move vertically relative to the frame. The two sets of pulley wheels mounted respectively on the frame and on the cross-member constitute a pulley block system. By moving the two sets of pulley wheels apart, the elevator is caused to move up through a distance which is equal to the displacement of the actuator rod multiplied by the number of cable strands passing over the pulleys, given that the two sets of pulley wheels constitute a pulley block system. For example, if each set of pulley wheels has four pulley wheels, then the effective stroke of the elevator is eight times the effective stroke of the actuator.
In a preferred embodiment, the horizontal cross-member is disposed beneath the frame.
It will be understood that this disposition is highly advantageous since there is necessarily room available at the bottom of the ele
REFERENCES:
patent: 4333549 (1982-06-01), Davis
patent: 4674938 (1987-06-01), Van Stokes et al.
patent: 4830146 (1989-05-01), Nakamura et al.
patent: 5636712 (1997-06-01), Muller et al.
patent: 5653311 (1997-08-01), Heikkinen et al.
patent: 5750945 (1998-05-01), Fuller et al.
patent: 5833031 (1998-11-01), Liebetrau et al.
Chin Paul T.
Kramer Dean J.
LandOfFree
Lift driving device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lift driving device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lift driving device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1249432