GB627303A - Improvements relating to hand operated stackers and more especially to winch mechanism therefor - Google Patents

Abstract

627,303. Hand-operated stacking-machines. SLINGSBY, G., and SLINGSBY, C. July 31, 1946, No. 22781. [Classes 78 (iii) and 78 (v)] A winch for a hand operated stacker comprises a winding handle 23 coupled with a rotatable casing 28 containing a friction clutch and brake mechanism (e.g. 42, 35, 30) coaxial with a driving shaft 24 and driving pinion 25, and means (e.g. pawl 31) for preventing the casing from rotating in the unwinding direction, the arrangement being such that by rotation of the winding handle in one direction the winding handle is coupled to the driving shaft through the casing and the clutch, and when the winding handle is released the driving shaft is held stationary by the said means which prevent reverse rotation of the casing and the clutch, whilst when the winding handle is turned manually through a few degrees in the reverse direction the clutch is disengaged and the driving shaft is thereby allowed to be rotated in the unwinding direction by the load, braking being effected with the aid of the clutch by the winding handle being turned through a few degrees in the winding-up direction. In Fig. 4, rotation of the handle 23 moves threaded boss 34 inwards relative to the casing 28 so that disc 42, which is slidably keyed to shaft 24, is thereby pushed to the right and engages the shaped face of brake shoe 35. The latter is then held between movable disc 42 and fixed disc 43 and expands so as to lock together handle, casing, discs and shaft; thus disc 42 rotates with the handle and winds up the drum 18 through gearing 25, 20, 21, 22. When the handle is released the casing 28 is held by pawl 31 and the casing holds the shaft and handle through the brake which is maintained by spring 36 which couples the casing 28 to the threaded boss 34 and operates so as to continue to wind in the handle. When the handle is unwound several times and held against the spring the pressure on the disc is released and the brake shoe contracts to free the shaft which unwinds under the action of the load. If the handle is now momentarily released the spring will come into play and brake the descending load. Centrifugal governor 37, Fig. 6. The speed of unwind under " free load may also be limited by governor member 37 which is pivoted at 38 to plate 39, which plate is integral with disc 42 and carries stop 40. As the load descends, shaft 24 rotates and the plate rotates with it so that increase of speed causes member 37 to swing outwards and increases the gap between nose 37<SP>1</SP> of member 37 and stop 40 and thus exerts pressure upon brake shoe 35 and brakes the load. Fig. 2. The winch is applied to stacker 1 to raise platform 8 which runs on rollers 9 in channels 2. The platform may have rollers 11 and be pivoted at 12 and be limited in movement by stops 13, 14 or may comprise pivoted forks.