GB877209A - Improvements in or relating to web feeding mechanism - Google Patents

Abstract

877,209. Control of several motors; actuation of switches. ELECTRIC & MUSICAL INDUSTRIES Ltd. Feb. 27, 1958 [March 9, 1957], No. 7861/57. Classes 38 (3) and 38 (5). [Also in Groups XVI and XXXVIII] The subject-matter of this Specification is substantially the same as that described in Specification 877,210, but is especially concerned with an electric direction-responsive switch 34, the operation of which ensures that the tape is held taut during deceleration, between the respective supply rolls and capstan rollers associated therewith. The switch is caused to open whenever the capstan roller associated with one of the supply spools, is rotated by the pull of the tape in a direction opposite to that in which the capstan is driven by its driving motor 27. Opening of the switch 34 causes de-energization of an electric motor, not shown, driving the associated supply spool, thereby permitting the capstan roller to rotate in its normal direction until the switch 34 is again closed. The switch 34 is included in the circuit to the motor driving the supply spool. Thus, when the switch is opened the supply spool motor is de-energized, but is closed again when the capstan roller rotates in its normal direction of rotation, thereby re-energizing the supply spool motor. The switch 34 is a mercury switch mounted on a plate 35a pivotally mounted at 36 on the motor 27. The plate 35a has a fork 37 engaging an eccentric 38 mounted on the shaft 39 of the motor 27. The eccentric 38 is driven by the shaft 39 through a friction coupling so that when the shaft is rotating in one direction the plate 35a is tilted against a stop during continued rotation of the shaft. When the direction of rotation of the motor is reversed, by the reverse pull of the tape, the plate is tilted back into engagement with a further stop.