Patent GB-1094088-A (GB)
Title: Improvements in or relating to slide projectors
IPC: G03B23/06
Filed: 1966-08-09
Abstract: 1,094,088. Optical slide projection apparatus. HONEYWELL Inc. Aug. 9, 1966 [Aug. 16, 1965 (4)], No.35582/66. Heading G2J. In a slide projector having a motor or manually rotatable frusto-conical slide tray 20, each slide carries magnetizable material and may be radially withdrawn from and returned to the tray by a magnet which is movable towards and away from the tray. The magnet also rotates about an axis parallel to that of the tray. Slide tray 20 comprises radial spacers (70), Fig. 8 (not shown), which extend from a disc (64) integral with hub (66) and define peripherally open slide compartments, the radially inner portions of the spacers being cut away. Ring (62) is supported on the spacers. Slides are retained by a bendable snap-on transparent slide selecting indexing lid (84) whose flange (100) has a single slot at (102), in register with a magnet, through which a slide may be drawn. Slide numbers on ring (62) are viewed through magnifying portion (110) of the lid. The lid is rotatable with respect to the tray. The outer end of hub (66) has grooves forming a hand-grip for rotation of the tray relative to the lid, while the disc (64) has teeth (124) for indexing. Slide-changing. A cam system driven by a single reversible motor through a solenoid-operated clutch operates a linkage comprising a follower (344), drive arm (346) and drive bar (352), Fig. 16 (not shown), to lower magnet (372) towards the tray periphery and allow the magnet to dwell while the tray is rotated and then to raise the magnet with a slide (80). Nylon gears and cams are used. An editing plate (402), Fig. 21 (not shown), is slidable in the plane of a slide in the projection position to engage and withdraw the slide for inspection or removal without moving the tray. Indexing mechanism. A secondary cam (324) integral with cam (322), Fig. 16, operates a shutter (470), Fig. 9 (not shown), a further linkage freeing a locking tooth (484) of an index slide (482), Fig. 20 (not shown), from the teeth (124) to permit forward or reverse rotation of the tray by pinion (486) against detent (487). Pinion (486) is rotated by one slide width as the cam system turns the single-toothed gear-wheel (326) through one indexing revolution. Further cam rotation returns tooth (484) to the tray locking position. Slide-changing then proceeds. Automatic focusing. The system disclosed in U. K. Specification 1, 016, 567 is used to focus on the new slide at the projection gate and is actuated through a switch controlled by the cam system. Lens (220) is driven in carrier (216), Fig. 9, on a ball and groove suspension through a linkage from the clutch to the motor (146), the linkage including a face cam with an eccentric groove engaging a follower pin on the lens mount. A damping system slows the motor before focusing commences. Interlocking of the projector movements is provided by a cam which prevents tray rotation with a slide in the gate, allows editing only when drive bar (352) is in the upper position, prevents slide changing with the edit plate (402) withdrawn, and allows tray indexing only when bar (352) and magnet (372) are in the lower position. Tilt. Adjustable front legs 54, 56 allow the elevation of the projector to be altered.