Elevator – industrial lift truck – or stationary lift for vehicle – Having specific means contacting or on load support for... – Includes movable contact component on support for engaging...
Reexamination Certificate
1996-11-21
2001-01-30
Ellis, Christopher P. (Department: 3615)
Elevator, industrial lift truck, or stationary lift for vehicle
Having specific means contacting or on load support for...
Includes movable contact component on support for engaging...
Reexamination Certificate
active
06179090
ABSTRACT:
FIELD OF INVENTION
This invention relates to elevators and is particularly directed to improved apparatus for controllably releasing the hoist brake of an elevator to permit smooth, controlled “drifting” of the elevator to an adjacent floor during power outages, natural disasters and the like.
PRIOR ART
As is well known, passenger elevators are typically raised or lowered by a cable which runs over a pulley located at the top of the elevator shaft. The elevator car is attached to one end of the cable, while a counterweight, equal to the weight of the elevator car plus several passengers, is attached to the opposite end of the cable. The car and counterweight run up and down the shaft on guide rails and an electric motor, needing only enough power to raise the difference in weight between the car and the counterweight, drives the pulley to move the car. When the car is stopped, for example, at a desired floor, a hoist brake acts to hold the car at the desired location. The hoist brake is typically urged on by springs and is released by a solenoid. Thus, a power outage serves to set the brake to safely lock the car wherever it is within the elevator shaft until power is restored. Unfortunately, electrical or power failure prompting this emergency braking action often results in passengers being trapped in the elevator car at a location between floors until rescue personnel can open the shaft doors and reach the elevator car by ropes or ladders or moving another elevator car along side to remove the trapped passengers. However, this involves considerable time and risk for the passengers. Furthermore, such time-consuming rescues require a plurality of rescue personnel and demand that the passengers crawl through a trap door onto the roof of the elevator car in order to reach the ropes or ladders or an adjacent elevator car. However, this may be difficult or impossible for some passengers, especially those who are obese, elderly or handicapped. More importantly, in natural emergencies, it may be a considerable time before a sufficient number of rescue personnel are available to effect such rescues, which are time consuming in themselves. Obviously, the longer the wait for rescue, the greater is the peril from fire, smoke and after-shocks. Furthermore, where the power outage has been caused by an earthquake, there is danger or aftershocks which may dislodge chunks of concrete or other structural material within the elevator shaft, causing increased danger to both the rescuers and to the evacuating passengers. Clearly, it would be desirable to provide apparatus which would enable a single individual to effect a controlled release of the hoist brake to facilitate prompt rescue of trapped passengers. Apparatus for accomplishing one man release and control of elevator hoist brakes have been proposed heretofore. However, prior art elevator hoist brake release devices serve to fully release the elevator brake, allowing the car to “drift” uncontrollably and at constantly increasing speeds, which are difficult to stop and which actually increase the danger to the passengers. Thus, none of the prior art elevator brake release devices have been entirely satisfactory.
BRIEF SUMMARY AND OBJECTS OF INVENTION
These disadvantages of the prior art are overcome with the present invention and an improved elevator hoist brake release and control device is proposed which is simple and inexpensive to produce and purchase, yet which enables a single individual to quickly and easily release an elevator hoist brake in a controlled manner to permit safely “drifting” the elevator car in a controlled, constant and predictable manner to an adjacent floor to allow trapped passenger to escape.
The advantages of the present invention are preferably attained by providing improved apparatus for manually releasing and controlling an elevator hoist brake having brake shoes urgeable into locking position by brake springs, said apparatus comprising a support bar, a first arm mounted adjacent one end of said support bar and carrying first brake release means engageable with one end of said brake springs, a second arm located adjacent the opposite end of said support bar, a compound lever which is generally V-shaped having one elongated leg and one short leg with the short leg being pivotally mounted on said second arm, and a generally L-shaped member having a short leg pivotally mounted adjacent the free end of said second arm and having a long leg pivotally connected to the long leg of said lever, and second brake release means pivotally mounted adjacent the intersection of the legs of said L-shaped member and engageable with the opposite end of said brake springs so that movement of said lever will drive said brake release means toward each other to accomplish controlled movement of said brake against the urging of said springs.
Accordingly, it is an object of the present invention to provide improved apparatus for releasing and controlling elevator hoist brakes.
Another object of the present invention is to provide improved means for manually releasing and controlling elevator hoist brakes.
An additional object of the present invention is to provide improved means for manually releasing and controlling elevator hoist brakes which can be actuated by a single individual.
A further object of the present invention is to provide improved means for manually releasing and controlling elevator hoist brakes which is simple and inexpensive to produce and purchase.
Another object of the present invention is to provide improved means for manually releasing and controlling elevator hoist brakes which enables a single individual to quickly and easily release an elevator hoist brake in a controlled manner to permit safely “drifting” the elevator car to an adjacent floor to allow trapped passenger to escape.
A specific object of the present invention is to provide improved means for manually releasing and controlling elevator hoist brakes having brake shoes urgeable into locking position by brake springs, said apparatus comprising a support bar, a first arm mounted adjacent one end of said support bar and carrying first brake release means engageable with one end of said brake springs, a second arm located adjacent the opposite end of said support bar, a compound lever which is generally V-shaped having one elongated leg and one short leg with the short leg being pivotally mounted on said second arm, and a generally L-shaped member having a short leg pivotally mounted adjacent the free end of said second arm and having a long leg pivotally connected to the long leg of said lever, and second brake release means pivotally mounted adjacent the intersection of the legs of said L-shaped member and engageable with the opposite end of said brake springs so that movement of said lever will drive said brake release means toward each other to accomplish controlled movement of said brake against the urging of said springs.
These and other objects and features of the present invention will be apparent from the following detailed description, taken with reference to the figures of the accompanying drawing.
REFERENCES:
patent: 4923055 (1990-05-01), Holland
patent: 5228364 (1993-07-01), Casas
patent: 5425435 (1995-06-01), Gregory
patent: 5873434 (1999-02-01), Sugita
patent: 5890565 (1999-04-01), Wang
Ellis Christopher P.
Sperry Robert M.
Tran Khoi H.
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