OVERLOAD PROTECTION DEVICE FOR HOISTS OVERLOAD PROTECTION DEVICE FOR HOISTS

摘要

1439275 Elevation overload safety device LINDEN ALIMAK AB 6 June 1973 [6 June 1972] 26913/73 Heading B8L An overload protection device for a hoist in which the hoist driving unit mounted on plate 11 is coupled directly to the hoist cage 6 through a load transmitter unit 16, which is flexible, permitting relative movement between the cage 6 and driving unit corresponding to the cage load, to produce a signal preventing starting of the hoist drive if a maximum permissible load on the cage has been exceeded. The driving unit includes driving pinions 12 engaging a rack 13 secured to a pylon 1, up and down which the cage moves. The driving unit plate 11 is guided by rack back engaging rollers 14 and spherical sliding bearings 15 between the plate 11 and vertical beams 8 of the cage 6, and the only force transmitted between the cage 6 and plate 11 is through the unit 16. The latter may be positioned relative to the cage to transmit either pressure or traction forces. The load transmitter unit 16 comprises a damper secured to the plate 11 and a yoke secured to the cage 6, the yoke including microswitches actuated by the damper upon relative movement of cage 6 and plate 11, beyond a preset limit representing a preset load. The hoist driving unit and load transmitter may be positioned above, below or within the cage 6.