Brake device for trolley wheels using a probe which, as required, interacts with the ground

摘要

A brake device for wheels of self-service trolleys is actuated by a magnetic field emitted by the ground and makes use of the fact that identical magnetic poles repel each other and opposite poles attract. A magnetic strip laid at the entrance to the transport belt acts directly on a slide (12) which has a blocking projection (13) and a sensor (14), or on a permanent magnet (18) which is attached to the said slide (12), in such a way that the slide is released from its position remote from the ground and blocks the wheel after the sensor dips into a groove on the transport belt whilst a magnetic strip which is laid at the exit and has the reverse polarity brings about the return of the slide (12) into the position remote from the ground. The advantage of this arrangement in relation to the prior art consists in the fact that, when travelling on normal ground, the sensor does not touch it and that only a single moving part is present which can run particularly in guides with a relatively large degree of tolerance. IMAGE