Patent GB-496058-A (GB)
Title: Improvement in method and apparatus for controlling movement of a web
IPC: B41J15/04
Filed: 1937-05-28
Abstract: 496,058. Automatic control systems. TRANS - LUX CORPORATION, (formerly TRANS-LUX DAYLIGHT PICTURE SCREEN CORPORATION). May 28, 1937, No. 14902. Convention date, Sept. 19, 1936. [Class 38 (iv)] [Also in Groups XVI and XVIII] Tension.-In a method of controlling movement of a web which is printed in an automaticallyactuated typewriter or the like and moved across a projection field by means of an automatically-actuated feed device, the typewriter types at least a substantial part of a line of information transversely of a web section while the latter is stationary, and while that web section remains stationary another section is moved through the projection field at a speed which is only fractionally as great as the speed of moving the web in the typewriter at the conclusion of each line-typing operation. As shown, a printing-device T, such as a motor-operated typewriter or the like feeds a web W forward a line space at a time, and feed rolls arranged above a projector P pull the web across the light aperture in the projector. A plate 18 secured in front of the projector has two pairs of spaced ears pivotally supporting a frame 23 which carries a bracket 31 for a lens 32. The bracket has depending arms supporting an inclined mirror 34. The plate 18 has lugs 35 in which is rotatably mounted the shaft 36 of a feed roll 37 having a corrugated surface, this roll being adapted to coact with a pair of short corrugated rolls 42 on a shaft pivotally mounted in weighted arms 40 on the frame 23. The web W passes between these feed rolls and the shaft 36 is driven from an electric motor 58. A plate 44 secured to the projector has an inclined section engaged by a number of spaced edged discs or the like 45a secured on a transverse shaft 45. This shaft is mounted in blocks secured by leaf springs 48 to depending arms 47 of the frame 23. The web W is passed between the plate 44 and the coacting discs 45a. Between the plate 44 and a pair of short rolls 8 coacting with the typewriter platen 5, the web is engaged by a control member 50 comprising a transverse shaft with spaced edged discs thereon and mounted in a pair of arms 51 pivoted to the ends of the arms 47 of the frame 23. One arm 51 has secured thereto a weighted member 52 carrying an electrical contact 54, this member 52 tending to swing the arm 51, and hence the control member 50, in an anticlockwise direction, whereupon the contact 54 engages a fixed electrical contact 55 secured to the adjacent arm 47. The contacts 54, 55 are in the circuit of the motor 58. When the web W is taut between the rolls 8 and the plate 44 the motor 58 is stopped, but as soon as the typewriter T issues an amount of web equivalent to a line space, the slack formed in the web allows the control member 50 to swing sufficiently to enable the contacts 54, 55 to be closed, and the motor 58 drives the feed rolls 37, 42 to draw the web across the projector P but at a slower speed than the speed of delivery from the typewriter by the platen 5. When the slack is taken up in the web the contacts 54, 55 are separated to stop the motor. Assuming the web is taut between the plate 44 and platen 5, movement of the latter to upper case position does not allow the contacts 54, 55 to close. The web may be rewound on a reel 63 rotated from the shaft 36 of the feed roll 37 by means of a spring belt 65. Threading of the web through the device is facilitated by the fact that the frame 23 carrying the feed rolls 42, control member 50, and shaft 45 can be swung away from the light aperture of the projector. The projector may be mounted in a cabinet 12. In a modification, the control member is spring-pressed against the web, and is mounted on the light housing of the projector. In further modifications described below the control member is not biassed towards the web. (a) The web when slack is blown by air from a nozzle to press a movable contact against a fixed contact to close the motor circuit. (b) The web when taut closes the opening to the atmosphere of a suction device, whereupon the pressure in the latter is lowered, and a piston rises to break the motor circuit. (c) The web when slack is sucked by a suction device to close the opening thereof to the atmosphere, whereupon a piston rises to close the motor circuit. (d) The web passes around rolls on a pivoted lever which has a mirror thereon adapted to reflect the light from a lamp on to a photo-electric cell which energizes a relay in the motor circuit to close the latter. The web when taut depresses the lever so that the light beam no longer strikes the photo-electric cell, and the motor circuit is opened.