GB225631A - Improvements in kinematographic projection - Google Patents

Abstract

225,631. Birkett, R. W. Sept. 7, 1923. Systems controlling reciprocating motion. - Two films are fed vertically in opposite directions by intermittently rotated sprockets, mechanism being provided for periodically reversing the direction of rotation of each sprocket and simultaneously moving the films laterally in relation to the optical system; the operations may be controlled by integrally driven switch gear, and etectromagnetic clutches may be provided to enable the spools serving for the time being as take-up spools to be connected to the driving mechanism. As shown in Fig. 1. films 10, 17, run between spools 12, 14 and 8, 16 respectively, over sprockets 9<a>, 13, 6, 15, the films, spools, and sprockets being mounted on a laterally movable carriage 1, 2. The sprockets 6. 9<a> are driven in opposite directions from an intermittently rotated pinion P by pinions 5<a>, 9<b>, the pinion P being long enough to engage the pinion 5<a> in each position of the carriage. Gearing is provided as shown to drive the upper sprockets 13, 15 and also the spools, magnetic clutches 22 - - 22<c> being provided in connection with the spools. The carriage is moved by solenoids 18, 19, the armatures 20, 21 of which are connected together and to the plate 2. The solenoids and clutches are connected as indicated diagrammatically in Fig. 4 to a barrel switch operated as shown in Fig. 3. The switch barrel 28 is secured to a weighted lever 27 which is engaged at the end of each film run by one or two nuts travalling on a threaded shaft'24 driven by the same means as the film mechanism. Each nut pushes the lever 27 into the vertical position, thus bringing the contact bars 29<a> on the barrel out of engagement with the fixed contacts, and breaking the circuits of the driving motor 31, of the solenoids, and of the magnetic clutches. The momentum of the mechanism causes the nut to travel sufficiently far to carrv the lever 27 over the dead point. The lever then falls to turn the barrel, thus connecting up the circuits necessary to drive the motor in the reverse direction, to traverse the carriage, and to energize the appropriate magnetic clutches. Reference has been directed by the Comptroller to Specifications 16382/13 and 201,202, [both in Class 97 (i), Optical systems &c.].