Lift brake for mine shaft conveyance system

摘要

Ore, personnel or equipment conveyances are driven vertically up and down the shaft as required by electromagnetic forces generated by linear motors. Each motor is constituted by a vertically extending winding support member and a reaction member, typically incorporating permanent magnets. Caliper brakes (22) are mounted on the conveyances or directly on the reaction members. Each brake has a mounting plate (24) which is secured to the underside of the conveyance and a pair of hydraulic brake actuators (26) which act on a caliper carrying brake pads (28) of friction material. The brake is released when load cells (34) sense a predetermined vertical load on the brake e.g. 90% of the upward thrust required to support the dead weight of the conveyance. Thus caliper pads acting on vertical guide rails may be released by hydraulic actuators operating against spring forces. @(11pp Dwg.No.2/3)@<<>/AB> DE4106606-A Tie-rod esp. for controlling car engine w.r.t. chassis A tie-rod is interconnected between two objects (12, 14) e.g. a vehicle engine and a vehicle chassis, to limit relative movement of the two objects. An isolator (15) e.g. a resilient spring is rigidly connected to an anchor part (11) connected to one object (12) and a variable length connection (21, 22) is connected between the isolator and another anchor part (13) connected to the other object (14). A detector (18) senses the relative positions of the two objects and this information is used to control the length of the variable length connection to control the relative position of the two objects for example, to maintain the two objects with constant spacing. The length of the variable length connection is varied to compress or extend the isolator so as to resist forces causing relative movement of the objects. Preferably the variable length connection is a piston and cylinder. Position control is provided by an electrical circuit.