Patent GB-1110512-A (GB)
Title: A motor-driven transparency projection apparatus
IPC: G03B23/04
Filed: 1965-07-12
Abstract: 1,110,512. Slide projection apparatus. USINES GUSTAVE STAAR S.A. July 12, 1965 [July 13, 1964], No.29513/65. Heading G2J. A motor-driven slide projector with automatic slide changing has separate and independent reversible motors to index the magazine 23 and to operate the reciprocating slide moving device 42-43-44, the magazine bearing a plurality of information elements which are actuated in a predetermined sequence to control slide changing. Magazine 23 moves in a channel 22 on guides 27, 28 having gaps 32, 33 to allow the passage of push elements 41, 41' of the slide mover, there also being provided at gap 32, a pinion 36 engaging rack 25 on the magazine and driven by motor 38. Flexible strip 47 secured to the slide mover is clamped between roller 48, driven by reversible motor 50, and spring-loaded roller 51 as in Fig. 5 (not shown) for the slide-changing movement. A Z-section member attached to device 42-43-44 has a projection 63 on its lower arm whose studs 61, 62 act upon strip 68 of reversing switch 64 for motor 50 as in Fig. 6 (not shown). Slide selection. An insulating plate 104 beneath channel 22 has a conductive band 105 bearing an angle section 106-107 to which are connected strips 108 which co-operate with a conductive U-section rail 109 connected by a lead 109' to switch 81-82, as in Figs. 3, 4 and 30 (not shown). Strips 108 pass through rocking levers 110 bearing strips 111 which may back contact separate conductive bands 112 on plate 104 which are each joined to a strip 113. The lever 110 corresponding to the required slide is rocked in direction F until strip 108 touches rail 109. Pinion 36 is in the disengaged position of Fig. 14 (not shown) and the magazine is manually brought to the initial meshing position of Fig. 17 (not shown). A transverse conductive tongue 117 of the magazine touches all strips 113 and current passes to motor 50 so that the slide mover is withdrawn. At the end of this movement, reversing switch 64 pivots at 66 and strip 67 leaves contact 73 to stop motor 50. Also, lever 80 is shifted by stud 61 on member 63 to close switches 81-82 and so activate motor 38 which then drives the magazine forward until a contact 113 is touched by way of slot 114, with the electrically conductive projection 115 on the conductive base of the magazine corresponding to the selected slide as in Fig. 33 (not shown). Current then passes to motor 50 to load the slide for projection and the motor 38 is stopped as stud 61 no longer touches 80. At the projection position, the circuit of motor 50 is broken and movement stops. The slide is returned to the magazine when button 123 in Fig. 36 (not shown) is pressed to reverse motor 50 until stopped by switch 64. The magazine is then advanced until projection 31 on its base rocks lever 84-85-86 and reverse motor 38 using switch 83, when the magazine moves backwards with motor 50 inactive and irrespective of levers 110, until another projection 30 again rocks lever 84-85-86 to reverse the motor. The magazine is then advanced to the projection position of the next selected slide as above. If more than one lever 110 were rocked as for projection of a plurality of slides, a succession of pulses are sent to motor 50 as the magazine advances after the first projection, each pulse resulting in a further projection. Since motor 50 is always rendered inactive during reverse motion of the magazine, repeated projection of a selection of slides always occurs in the same sequence. In modified versions, projections 115 are replaced by vertically slidable elements 153 on the magazine, one for each slide compartment, whose operative displacement may be sensed as above or photo-electrically. Again, a standard magazine may be used resting on a carriage provided with members 115 5 or 153 as above. The magazine may be provided with permanent information elements to start operation for each of the successive slide recesses in one direction of movement, while the elements may be kept inoperative in the opposite direction.