Patent ID: 6178891
Filing Date: 2001-01-30
Classification: B61C

Abstract:
An assembly unit for use on an undercarriage of a suspended trolley line, which includes a running rail, a supplemental rail positioned at least occasionally along the running rail and substantially parallel to the running rail with a spacing therebetween, and at least one undercarriage having a front and a rear and including a running wheel that is at least occasionally driven along the running rail, such that the least one undercarriage is movable along the running rail, said assembly unit comprising:at least two frictional wheels positioned apart from each other and adapted to contact the running wheel;a connecting element which is adapted to guide said at least two frictional wheels on the undercarriage; anda spring element which biases each of said at least two frictional wheels against the other, wherein said assembly unit is adapted to be guided on the undercarriage by a guide element such that said assembly unit is movable about the running wheel between an operating position and a neutral position, a front frictional wheel being movable to provide clearance from the supplemental rail in said neutral position, when the undercarriage is in an area of the trolley line where the supplemental rail is present, said assembly unit is in said operating position, said at least two frictional wheels being operable to contact the supplemental rail and the running wheel in said operating position, thereby exerting a pressure upon the running wheel, said assembly unit being pivotable about the running wheel in response to a rear frictional wheel contacting the supplemental rail and thereby moving said assembly unit into said operating position.