GB914631A - Improvements in or relating to means for controlling the tension in magnetisable tape - Google Patents

Abstract

914,631. Automatic tension control. ELECTRIC & MUSICAL INDUSTRIES Ltd. April 15, 1959 [April 24, 1958], No. 12985/58. Class 38 (4). In magnetizable tape transducing apparatus in which tape may be taken up on or released from a spool driven or braked by an electric motor, an arm moves about a pivot in response to variations in tape tension and thereby operates pressure-responsive electrical means to maintain constant tension by variation of the energization of the motor. As shown, magnetic recording tape 2 unwound from a spool 1 by a driven capstan 7 associated with pinch rollers 11 is supplied to a take-up spool (not shown). Tape tension on the input side of the capstan is automatically maintained constant by a jockey roller 3 mounted on a spring-loaded lever 4 which operates a multiple carbon pile regulator 13 controlling the energization of a motor (not shown) acting as a brake on spool 1. Movements of lever 4 are damped by a dashpot 14. A further jockey roller 9 is associated with a similar system (not shown) controlling the motor driving the take-up spool to maintain tape tension constant on the other side of the capstan. The arrangement also maintains the tensions constant when the tape is transported in the reverse direction. For fast spooling the carbon pile resistance associated with the take-up drive is arranged to be short-circuited when the pinch rollers 11 are freed. The Provisional Specification refers to cam adjustment of the end of the carbon pile remote from the lever and to compression by this cam during fast spooling.