| 摘要 |
846,009. Magnetic recording and reproducing apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. Feb. 13, 1957 [Feb. 16, 1956], No. 4888/57. Class 40(2). A number of magnetic recording-reproducing heads 11 are spaced along a common axis and are also spaced angularly about the axis, so that rotation of the assembly about the axis will bring any selected head into operative position relative to a magnetic record, such as a multitrack disc arranged to rotate therebeneath. As shown, the heads are highly permeable bars 11 bent round a tube 10 containing a common conductor 17, and the air gap 13 of the selected head is oriented relative to the record by a stepby-step motion imparted by a solenoid-actuated spring-retracted plunger 21a engaging a ratchet wheel 21 on the tube 10 which is steadied by a spring detent 22. Rack-and-pinion mechanism may also be provided to move the heads axially over, say, “-inch, within which each head may align with any one of six record tracks on the rotating disc; the wheel 21 is made wide for this purpose. The ends of the conductor 17 are connected to a single- or multi-turn winding of a transformer, the second winding of which receives the input or transmits the output. |
