Improvements in or relating to apparatus for winding web on and unwinding web from aspool

摘要

878,009. Feeding magnetic tapes. ELECTRIC & MUSICAL INDUSTRIES Ltd. Feb. 6, 1958 [Feb. 12, 1957], No. 4708/57. Class 40 (2). [Also in Groups XVI and XXIV] An apparatus for winding and unwinding a magnetic tape 1 from a spool 2 comprises a shaft 6 for carrying the spool, means for driving the shaft in one direction to wind tape on the spool, means for unwinding tape from the spool, the driving means being inoperative to drive the spool when the unwinding means is operative to unwind tape from the spool and a torsionally resilient coupling between the shaft and the driving means, the arrangement being such that when the unwinding means is operative, to unwind tape the coupling is stressed and when the unwinding means is inoperative the coupling tends to rotate the spool to wind tape thereon, thus tensioning the tape between the spool and unwinding means. The web 1 is unwound from the spool 2 by a capstan roller 4. The spool 2 supported on a shaft 6, is coupled to a shaft 11 by a resilient coupling comprising spring fingers 7 on the shaft 6 engaging pins 8 projecting from a disc 9 carried by a sleeve 10 rotatable on the shaft 11. The sleeve 10 has a disc 12 fitted between felt rings 13 fitted between a driving flange 14 and a disc 15 urged together by springs 17 on pins 16. The flange 14 is rotatably mounted on the shaft 11 and is driven through a one-way clutch by a crank 18 having a crank-pin 19. The crank 18 has a boss 20 which is locked during clockwise rotation to an annular flange 23 on the flange 14 by balls 22 engaging inclined flats 21 on the boss 20. Thus, when the crank is driven clockwise, the drive is transmitted to the spool 2. When tape is to be unwound from the spool the crank is driven counterclockwise, the annular flange being held stationary by a pivoted arm 25 having a curved end 26. When the capstan roller is stopped the spool 2 tends to overrun thereby stressing the springs 7 which then cause reverse rotation to prevent slackness of the tape between the spool 2 and roller 4. The spool 3 may be driven in the same manner as the spool 2. Specification 878,008 is referred to.