GB938421A - Improvements in or relating to web transporting apparatus - Google Patents

Abstract

938,421. Feeding webs. ELECTRIC & MUSICAL INDUSTRIES Ltd. April 11, 1960 [April 18, 1959], No. 13282/59. Class 100 (1). [Also in Group XXXVIII] Web transporting apparatus for use in, e.g. a magnetic recording machine, comprises means for mounting two spools, means for winding the web from one spool to the other, brakes to stop the spools, means to keep the brakes normally inoperative and means sensitive to the direction of movement of the web, whereby on application of the brakes a larger braking force is applied to the spool from which the web is being unwound compared with the braking force applied to the winding spool. In the embodiment described the shafts 1, 2, carrying the spools have motors energized as described in Specification 933,862, which may have a D.C. braking voltage applied. Mechanical brakes have drums 4, 5 and brake bands 6, 7 anchored at one end to blocks 8, 9, and at the other end connected to slides 10, 11 guided in brackets 12, 13. Springs 14, 15 urge bands 6, 7 into engagement with drums 4 and 5. Slides 10, 11 are coupled to arms 16, 17 of bell-crank levers whose other ends are coupled to a solenoid armature 22. The capstan roller 3 is frictionally coupled to a disc 30 carrying a peripheral projection 31. When the capstan roller is rotating anticlockwise the projection is in the position shown by the full lines, and on reversal of the rotation it is in the position shown dotted. When operating the solenoid 23 is energized and the brakes are maintained OFF. When the solenoid is de-energized, the appropriate drum (according to the direction of rotation of the capstan roller) is given a greater braking force.