GB177907A - Means for preventing unauthorized use of pulley hoists - Google Patents

Abstract

177,907. Brown, A. B. Jan. 20, 1921. Pulley-blocks; sustaining at limit of wind.- Consists in means for preventing normal working of pulley blocks provided with load-sustaining means of the kind described in Specification 177,233 in which the sheave casing 3 has an extension 4 carrying a pivot 6 which supports a pair of inverted T-arms 7 adapted to extend through slots in the casing so as to support the upper block 23. A second pivot 11 supports a rocking arm 12, the lower end of which normally projects through a slot into the casing and the upper end co-operates with a pin 14 bridging the arms 7, a projection 15 on the arm 12 engaging a bent lever 16, the other arm of which is adapted to engage a notch 16<b> on one of the arms 7. According to the present invention the abutment piece 21 is perforated, the rope passing through it and being endless. In operation, a removable clamp 28 is fixed to the rope and the rope hauled over the pulley 1 until the clamp engages the lower end of the abutment piece 21 and the load is raised until the block 23 is forced past the arms 7 which spring back, so that the rope can be slackened thus allowing the block to rest on the arms and so support the load. By removing the clamp unauthorized use of the appliance is prevented. To lower the load, the clamp is replaced and the rope hauled in so that the block again pushes back the arms which are temporarily held bv the detent 16 engaging the notch 16<b> until the lower block 24 during the lowering operation strikes the arm 12 and releases the arms 7.