Patent GB-766445-A (GB)
Title: Improvements in or relating to dictation apparatus
IPC: G11B5/004
Filed: 1954-01-27
Abstract: 766,445. Magnetic sound recording and reproducing apparatus. DICTAPHONE CORPORATION. Jan. 27, 1954 [Feb. 11, 1953], No. 2493/54. Class 40 (2). A magnetic head 6 is correctly positioned on a belt record 3, by aligning a mark on the belt with a mark on the machine, and then driving the head across the belt until a cam on the drive for the head releases a lever 16 which tensions and thus drives the belt which travels around driving-rollers 22, 24 and idler rollers 18, 20, the roller 18 being movable by the lever 16. The rollers 22, 24 are driven by a belt (Fig. 7, not shown) from a motor 26 surrounded by a shield of soft iron or " Permalloy." The rollers are tilted slightly to force the belt down against flanges on the bottom of the rollers. The head 6 is mounted on a carriage 61 which is driven vertically across the belt by a feed-screw 63. Engagement of the head with the screw is controlled by a pivotally-mounted member 65 which engages between lugs on the carriage and is spring-urged to force the carriage against the screw. Depression of a knob 14 causes rotation of the member 65 to move the carriage away from the screw 63. Movement of the knob 14 along a slot 112 in a panel 106 causes the carriage to be moved vertically through a flexible cable 114. The head may be given an incremental back space by energizing a solenoid (see Fig. 6, not shown) to move the carriage away from the screw, the carriage then being moved downwardly by a spring-urged pawl 130. When a recording has been made, the lever 16 is moved to release the tension on the belt and allow it to be removed. Simultaneously a member 16b on the lever causes a contact 16c to operate a switch 16a which actuates the solenoid to move the carriage away from the screw. At the same time, a guide-plate 53 is moved inwardly to engage a roller 156 and cause a lever 144, which carries a roller 141 fixed to the carriage, to rotate, and thus cause the carriage to be returned to its starting position. To indicate when the carriage reaches the end of its travel, a projection 166 on the lever 144 causes a clapper 162 to be moved away from a bell 160 against a spring 172 and then to be released to ring the bell. The motor 26 is stopped, when the carriage reaches the end of its travel by a projection 178 on the lever 144 which actuates a switch 175. A paper slip 182, Fig. 11, behind a plastic window 178 on the panel 106 may be given one perforation, e.g. to indicate a correction, by lifting the knob 14 to cause a pointed stylus 184 to perforate the paper. A double perforation, e.g. to indicate the end of a record, may be formed by rotating a knob 190, Fig. 3, to cause a stylus 188 to be raised. An auxiliary head (see Fig. 13, not shown) may be plugged into the main head 6 to provide duplicate recordings which may be cut apart by a knife 238, Fig. 3, normally spring (244)-urged out of the path of the belt. The machine may be controlled from a switch on a microphone or from a control unit (see Figs. 2 and 12, not shown) which may be fixed to a typewriter. The electric circuits of the machine and of the plug-in microphone and control unit are described (see Fig. 14, not shown).