Patent GB-897399-A (GB)
Title: Improvements in or relating to actuating mechanism for slide magazines
IPC: G03B23/04
Filed: 1960-11-29
Abstract: 897,399. Magazine advancing mechanisms. ZEISS IKON A.G. Nov. 29, 1960 [Dec. 5, 1959], No. 41004/60. Class 97(1). Mechanism for advancing in either direction the magazine of a slide projector comprises a rotatable drum, adapted to be coupled to a driving motor in an associated projector for rotation in one direction only, and a rotatable member for engaging and advancing an associated magazine when the latter is in position, the said drum carrying adjustable cam means for engaging the said rotatable member so as to cause rotation thereof in opposite senses in dependence upon the setting of the cam. As shown in Figs. 1, 2a and 2b, a pinion 9 engaging a rack 10 of a magazine is rigid with a rotatable member 6 having studs 7 between adjacent ones (71, 72) of which passes a peripheral flange 2 of drum 1. In a cut-away portion 3 of the latter is mounted a cam 4 rotatable on spindle 5 extending into the interior of the drum and terminating in a portion 14 urged by a spring 15 to set cam 4 into the position of Fig. 2a where on rotation of the drum 1 its right side will engage stud 71 to rotate wheel 6 clockwise by one stud interval. Cam 4 is set to the position of Fig. 2b for opposite rotation by axial movement of a shaft 12 against spring 15 caused by a lever 19 when a solenoid 16 is energized for a brief time, the shaft then being held by engagement of a rigid projection 22 thereof with a spring catch 21. Immediately after a unit of rotation a projection 25 on drum 1 will strike catch 21 so that cam 4 can return, under the pressure of spring 15, to the position of Fig. 2a (if it was previously in the position of Fig. 2b), and the drum will stop rotating, in a manner now to be described. Drum 1 is rigid with a hollow axle 33 on which is rotatably mounted a clutch disc 32 which has peripheral notches and is continuously driven by engagement of worm wheel 31, rigid with disc 32, with a worm 30 of a motor shaft (e.g. of a cooling motor in the projector). The hollow axle 33 has a rigid projection 36 carrying a pawl 35. This is urged into rotation, about an axis parallel with that of axle 33, by a torsion spring 38, in such a sense as to engage with the peripheral notches 34 (see Fig. 7) of the clutch disc 32, but is constrained from such engagement by an armature 40. On briefly energizing solenoid 41, pawl 35 will be released and drum I will be rotated once, armature 40 once more arresting projection 39 of pawl 35. For advancing the magazine in a direction corresponding to the cam-setting of Fig. 2b, solenoid 16 is energized (instead of solenoid 41) and pivoting of lever 19 to move the cam-adjusting shaft 12 also closes contacts 45 which then cause solenoid 41 to be energized. To allow free movement of the magazine, a locking slide 46 may be pushed into the path of pawl 35 so that drum 1 is stopped in such a position that studs 7 may pass freely in the space between cam 4 and the cut-away edge of the flange 2. Means may also be provided to break the circuits of solenoids 16 and 41 after a predetermined time in case the switches 42, 43 are held closed for too long.