Patent GB-494619-A (GB)
Title: Improvements in or relating to sound recording and reproducing apparatus
IPC: G11B5/00
Filed: 1937-09-29
Abstract: 494,619. Telegraphones ; reels or bobbins. ELECTRICAL RESEARCH PRODUCTS, Inc. Sept. 29, 1937, No. 26405. Convention date, Oct. 7, 1936. Addition to 389,117. [Class 40 (ii)] [Also in Group IX] A telegraphone in which the tape is magnetized by the system described in the parent Specification is provided with controls for adapting the apparatus to record or reproduce sound, or to rewind the tape, latching means for the controls for holding them in operative position, and means for preventing the latching means holding the recording and reproducing controls in operative position while permitting the tape to be rewound. General construction. The tape passes from a supply reel 14, between guide rollers 74, 76, felt wipers 64, 65, polarizing magnets 23, guides 84, recording and reproducing magnets 24, guides 85, 86, to a take-up reel 13. The supply reel comprises two discs 17, 18, spaced apart by a number of pins 15 arranged around the periphery thereof, between which discs is freely rotatable a grooved disc 12 on which the tape is wound. The take-up reel comprises two discs spaced apart by a number of pins 19 which latter serve as retaining means for the end of the tape at the commencement of the winding operation. The reels are driven by an electric motor 30 through belts 31, 43, and friction clutches 35, 41. The means for effecting the necessary mechanical and electrical connections is shown in Fig. 9, and comprises four press buttons for adapting the machine for the recording and reproduction of sound, for permitting rewinding of the tape, and for stopping the machine, and a two-part spring-loaded latch bar 98. Each button is provided with an enlarged portion c adapted to engage of pin d of the latch bar, such that upon depressing the button the latch bar is moved to the left until the button is fully depressed, when the latch bar is moved to the right by the return springs and holds the button in the depressed position. The buttons are also provided at their lower ends with further enlarged portions which operate electrical contact arms. The indicator for the take-up reel 13 comprises a pivoted pointer 117 which carries a roller 119 engaging with the tape wound on the reel. A press button 88 is also provided, the operation of which causes the separation of the magnets and tape wipers, and the engagement of the guide rollers 74, 76, to facilitate the threading of the end of the tape onto the take-up reel. Operation. To record sound upon the tape, the " record " button is pressed to effect the necessary electrical connections and to cause the lower end 89 of the button spindle to engage with a lever 90 to engage the clutch 41 and rotate the take-up reel 13. To reproduce a portion of the recorded matter, the " stop " button is first pressed. to move the latch bar to the left and thus release the "record" button, and the " rewind " button is then operated to rewind the appropriate portion of the tape on to the supply reel 14. Depression of the " rewind " button causes the lower end of the spindle 97 to engage a lever 94 and engage the clutch 35 to rotate the supply reel. The lever 94 is provided with a projecting portion 105, which operates a lever 106 to separate the magnets and tape wipers during the rewinding operation. When a sufficient length of tape has been rewound the " stop button is pressed, and then the " reproduce " button, the lower end of which latter engages with the lever 90 to operate the clutch 41 and thus cause rotation of the take-up reel. When the take-up reel is full, an extension 120 of the pointer 117 strikes a pin 121, attached to the left-hand portion of the latch bar 98 and slidable in a slot 122 in the right-hand portion, and moves the left-hand portion of the latch bar to the left to render the " record " and reproduce " buttons inoperative.