Patent GB-134893-A (GB)
IPC: G03B21/43
Abstract: 134,893. Stechbart, B. Nov. 7, 1918. Kinematograph apparatus.-In a kinematograph projector, the parts are so constructed and arranged that it may be used for rewinding the film, the feed mechanism being then locked, and the continuous sprockets being free, so that the rewinding may be effected by means of a handle on the shaft of the spool which normally pays out during projection. The paying-out spool is housed in a easing 13<1>, and the film passes over a .continuous sprocket on the hidden side of the casing 6 as seen in Fig. 4, then to the gate 48, intermittent sprocket 29, continuous sprocket 32, and the take-up spool within a casing 14<1>. The continuous sprockets 32. 33, Fig. 12, are mounted on a common shaft 30 which is driven through a clutch by a pinion 31 loose upon it and in gear with a wheel on the main driving-shaft 15. The spools 13, 14, Fig. 9, are mounted on parallel shafts 11, 12, extending in opposite directions, and are driven alternatively, and in opposite directions, by pulleys 65, 66 through pawls and ratchets 67, Fig. 4. The pulleys are connected by a belt 38 with a driving pulley 37, this arrangement permitting the film to be fed in either direction for projection. The belt is kept tight during projection by a pulley 71 on a pivoted frame 72. The shutter is driven through spiral gear wheels &c. from the main driving shaft, and has a notched disk which may be engaged by a bolt 84. When the projection of a film has been completed, and the film is to be rewound ready for feeding in the same direction during its next projection, a knob on the forward end of a rod 77 is pulled forward, being first unlocked by the withdrawal of a spring- actuated latch 81. This operation causes a link 75, Fig. 11, to turn about an axis coincident with the axis of the shaft 30, and disengage the clutch through which the sprockets 32, 33 are driven. It also lifts the frame 72 against the action of a spring 73, through a link 74, thus allowing the belt 38 to become slack, and causes a spring 86 to lift the bolt 84 and lock the driving-mechanism. The film is then threaded over the sprocket 32, between two pressure rollers 41, over the sprocket 33, its edge being engaged by a grooved roller 45, and on to the paying-out spool. The paying-out spool 14 is then directly driven by a removable crank handle so as to rewind the film, after which, by pressing back the knob on the rod 77, the mechanism is again in condition for projection. The clutch for the sprocket shaft 30 comprises a collar 88, Fig. 12, connected to the shaft, the collar having sliding pins 89 within it which engage in holes 90 in a disk connected to the pinion 31. The clutch is kept engaged by means of a collar 91 loose on the shaft 30 and having a groove engaged by a yoke 93 on a spindle 92 kept in position by a spring 94. When the rod 77 is pulled out, a cam 96, Fig. 11, on the link 75 engages a button 95 on the end of the spindle 92 and slides the spindle to disconnect the clutch. The driving-mechanism may be enclosed within a casing 6 secured to the front wall 1 of a box containing the spools, lamp-house, &c., and two pressure rollers 41, bearing on the sprocket 32 and spaced apart, may be carried on a swinging arm 40 pivoted on one side of the casing 6. One pressure roller may be similarly mounted on the opposite side of the casing, and this roller and one of the rollers 41 may have a tubular bore containing a spring-impelled bolt which engages in holes in the casing 6 to hold the rollers in operative or inoperative position. Each of the casings 13', 14' enclosing the film 'spools has rollers 61 arranged in a housing 60<1> over its peripheral opening. A valve 62 on a pivoted arm 63, normally supported by a roller 64 bearing on the film, falls into the space between the rollers to prevent the spread of fire to the spools if the film becomes ignited. The spools are mounted on their shafts by means of adjustable centring- cones 6 and which permit of their ready detachment. The lamp-house 3 has a cylindrical casing having ventilating-openings 106, 107, and carrying a condenser lens 105. The casing is carried by an annular bushing in the top wall of the box 1, and the lamp is preferably an electric incandescent lamp of the nitrogen gas type. Adjustable legs 110 preferably having hemispherical enlargements 111 are provided at the front of the box 1 so that the box may be tilted, clamping- screws 113 holding the legs in any adjusted position. Reference is made to Specification 134,803 as regards the construction and arrangement of the gate, intermittent sprocket 29, guide-plates, film-centring mechanism, &c., and to Speoification 134,802 as regards the provision of a condenser lens 108.