| 摘要 |
844,569. Magnetic recording &c. apparatus. AMPEX CORPORATION. Nov. 19, 1958 [Nov. 22, 1957], No. 37297/58. Class 40 (2). [Also in Groups XVI and XXXV] To enable rapid stopping and starting of a magnetic tape in the vicinity of the capstans 31, 34, chambers 14a, 14b are provided into which loops of tape are drawn by suction and automatic means maintain the length of the loops constant. In the steady state, the tape follows the path 11, 28, 26, 4a, 5a, 27, 29, 31, 32, 77 and correspondingly in the chamber 14a to the spool 12. The tape may be driven in either direction according as one or other of the pinch rollers 32, 33 is engaged with the tape. A detailed description of these rollers and their operation is the subject of Specification 844,568. Suction is applied at 40a and 40b in each chamber and, the radii of the half-loops 4a, 5a being defined by the width of the chambers in the regions 16, 17 respectively, a symmetrical disposition of the loops is obtained, due to the equal tape areas then projected towards each end of the chambers. Slots 38, 39 are partly in communication with suction at their outer ends, and partly in communication with the atmosphere in the region 14b. An intermediate pressure, which is a measure of the length of the tape loops is communicated by manifolding to a transducer (Fig. 6, not shown), which controls electronic means by which, in turn, the spool motors are driven so as to maintain constant the tape loop lengths. |
