Patent GB-1007535-A (GB)
Title: Improvements in or relating to magnetic recording apparatus
Inventor: SHIMMIN GEORGE PATTINSON
IPC: G11B5/004
Filed: 1962-10-01
Abstract: 1,007,535. Magnetic recording apparatus. CLARKE & SMITH OFFICE EQUIPMENT Ltd. Sept. 12. 1963 [Oct. ], 1962; Nov. 22, 1962], Nos. 37168/62 and 44159/62. Heading G5R. Recording apparatus including a plurality of magnetic recording heads mounted for rotation in a common plane about a common axis and equally spaced from one another about the axis of rotation, and band feeding mechanism adapted to feed a recording band past the heads in a plane parallel to the plane of rotation of the heads so that recording can be effected along a series of arcuate tracks extending across the band, is characterized in that the band feeding mechanism comprises a band-supporting plate having a first portion inclined to the plane of rotation of the heads and joining a second portion parallel to the plane, the second portion having an arcuate slot whose extremities extend into the first portion and the arrangement being such that the heads enter the slot progressively at one inclined extremity to engage the band and, after traversing the band, progressively withdraw from the slot at the other extremity. Referring to Figs. 3 and 4 three recording/ playback heads 20 are equally spaced on a platform 19 which is rotated by a motor 30 via a disc 28. The edge of platform 19 is provided with a worm 32 which engages a worm-wheel 33 mounted on a spindle 34 carrying sprocket wheels 39 and 40 which drive the band 41 of recording medium. The spindle 34 is mounted in a spring-biased bracket 35 which can be moved against the spring to disengage the drive and allow manual rotation of the spindle by knobs 46. A ratchet 48 on spindle 34 can be operated by a pawl (not shown in Figs. 3 and 4) actuated by a solenoid 55 to give back spacing. An arcuate slot 43 concentric with platform 19 and extending over slightly more than 120 degrees is provided in the lower portion 17 of a supporting plate, its ends extending into the ramp 18 joining the lower portion 17 to the upper portion 16. A pressure plate 44 hinged at 44a, 44b has an arcuate pressure pad 45 which bears on the record band 41 as it passes over slot 43 in moving from supply roll 42 to the sprockets 39, 40. The difference in height between the portions 16 and 17 of the supporting plate is such that as each head 20 is progressively moved from under the region of the band pressed down by pressure pad 45, the head is progressively taken out of engagement with the band. The heads may be energized in sequence as they pass into slot 43, but it is sufficient to connect them in series. A cutting head 60 may be mounted on the edge of pressure plate 44 and connected by a cord to a spring-loaded reel 66 via pulleys. When the head 60 is moved across the band 41 with its blade retracted, the movement of one of the pulleys by the cord is arranged to rotate spindle 34 and advance the band 41; when the head is released, its blade cuts the band 41. To prevent the band 41 being inserted incorrectly the sprockets 39 and 40 may be differently spaced from respective edge guide surfaces and/or the tooth spacing of the two sprockets may be different. In a modification, Fig. 9, the pressure plate 44 is pivotally mounted on a rod 80 which is a loose fit in apertures provided in lugs 86<SP>1</SP> on a mounting plate 82 hinged at 85. A spring 84 tends to separate the pressure plate 44 from the mounting plate 82. Thus the pressure plate 44 can tilt so that each side edge moves independently of the other. Specification 1,007,536 is referred to.