Patent ID: 6736242
Filing Date: 2004-05-18
Classification: B66B

Abstract:
An arrangement for a hoist having a hoist cage adapted to travel in a path in a hoist shaft, the arrangement secures safety zones in case persons should be outside the hoist cage in the hoist shaft and comprises:(a) mechanical means of limitation that can enter into the path of the hoist cage arranged at a distance from upper and lower end limits of the hoist cage during normal operation in order to form upper and lower safety end limits and mechanically secure the safety zones, said mechanical means of limitation having at least one striking surface arranged to tilt between an inactive state outside the path of the hoist cage and an active state in the path of the hoist cage forming the safety end limits, the at least one striking surface balanced to take the active state and a retaining device arranged on each striking surface to keep the at least one striking surface in the inactive state during normal operation and to release the at least one striking surface in a risk situation to take the active state; and (b) means of return arranged to return the at least one striking surface from the active state to the inactive state, said means of return comprises an electric motor and a leaf spring arranged between the at least one striking surface and the motor, the leaf spring arranged to pull in the at least one striking surface against the retaining device when the leaf spring is wound up by the motor and the leaf spring, when the retaining device releases the at least one striking surface, will assist in returning the at least one striking surface to the active state due to a tendency of the leaf spring to return to a linear form.