GB770993A - Improvements relating to endless belt conveyors - Google Patents

Abstract

770,993. Endless belt conveyers. MAVOR & COULSON, Ltd. July 14, 1954 [Dec. 15, 1952], No. 31687/52. Class 78 (1). The endless belt conveyer which is driven on its return run has an assembly of three pulleys, each movable lengthwise of the conveyer to form the belt into extensible and contractible loops, two of which extend on opposite sides of the driving gear and control the ratio of the respective ingoing and outgoing tensions by means of a motion-multiplying gear connected between their pulleys, whilst the length of the third loop is controlled by a manual take-up gear acting on its pulley. As shown, the belt 10 passes at the end of its conveying run over a pulley 29, and extends in a loop 10a formed by a slidable pulley 11, around a driving pulley 30 and snub pulley 31, in a second loop 10b formed by a slidable pulley 12, and in a third loop 10c formed by a slidable pulley 13. Pulleys 11, 12, 13 are mounted for horizontal sliding on carriages 14, 15, 16 respectively running on tracks (not shown). At each side of the belt a rope 25 anchored at 36 passes around a pulley 22 on carriage 14 to the smaller pulley 33 of a differential pulley gear, the larger pulley 34 of which has a rope 26 connected to it which passes around a pulley 23 on carriage 15 to an anchorage 37. The ratio between the diameters of pulleys 33 and 34 determines the ratio of tensions T1, T2 of the loops 10a, 10b. A rope 27 anchored at 38 passes around a pulley 24 on carriage 16 to a winch 35. The driving motor for pulley 30 may be a regenerative electric motor whereby, when the conveyer is used on an incline and the load is being conveyed downhill, the motor acts as a brake.