Patent GB-510619-A (GB)
Title: Improvements in apparatus for reproducing from sound records of strip form
IPC: G11B15/34
Filed: 1938-02-10
Abstract: 510,619. Optical sound-reproducing apparatus. FINCH, W. G. H. Feb. 10, 1938, No. 4251. [Class 40 (ii)] [Also in Class XX] Relates to apparatus for reproducing sound from strip records having a number of parallel sound-tracks which are optically scanned in turn by running the strip in successively opposite directions. According to the invention, the strip is driven by means adapted to be coupled to a continuously rotated flywheel for driving the strip in one direction and to another continuously rotated flywheel for reversing. the direction of travel of the strip, means being provided for engaging the strip and adapted, when a notch formed near an end of the strip is reached, to transfer the scanning from one sound track to the next and to transfer the drive coupling from one flywheel to the other. The invention is particularly intended for use with sound records printed along with comic or other pictures in newspapers or on separate sheets, and adapted to be severed from the sheets attached together, when required, to form long strips. In the apparatus shown, the sound-record 100, passing from one reel 104 to another 105, or vice versa, is fed by a sprocket 102 over a drum 108, where it is scanned by a narrow light beam from a lamp 111 projected perpendicularly upon a single sound track on the band. Sound-reproduction is effected by means of scattered light reflected from the record on to a photo-electric cell 112. The scanning system 111, 112 is fixed, and the strip is adapted to be shifted transversely, to change from one track to the next. For this purpose, the sprocket 102 and the drum 108 are carried by a plate 144 mounted on a bed plate 145 which is slidable in guides 204. The plate 145 is formed with rack teeth 147 engaged by a double-pawl escapement member 146, which is controlled by an electromagnet 151. Each time an impulse is transmitted through the magnet at the end of the travel of the film in either direction, the escapement is operated to allow a spring 148 to shift the plate 144 laterally through a distance equal to the spacing between the sound-tracks. The driving of the strip is effected by a motor (not shown) which, through bevel wheels 119, 120, continuously rotates flywheels 121, 122 in opposite directions. The flywheels are loose on a shaft 125 and are adapted to be coupled thereto in turn by a clutch 128, to drive it in one direction or the other. The shaft 125 is connected to the spindle of the sprocket 102 by a spliced coupling 143, and also carries pulleys 134, 135 which are connected to it through one-way clutches. The pulleys respectively. drive, through belts 136, 137 which permit slip, the spools 104, 105. The declutching of one flywheel and the clutching-in of the other are effected by magnets 160, 166, which are connected in circuit with batteries 152, with the magnet 151, and with pairs of contacts 164, 157 as shown. One member of each pair of contacts is formed with a feeler 159 or 165 bearing against the edge of the strip, and adapted to enter a notch 156 or 156' near either end of the strip to effect reversal of the strip when necessary and the accompanying operation of the transverse shifting mechanism. The notches may be formed in one edge of the strip as shown, or they may be in opposite edges.