Patent GB-435756-A (GB)
Title: Improvements in or relating to combined kinematographic projecting and sound recording apparatus
IPC: G03B31/02
Filed: 1934-01-22
Abstract: 435,756. Kinematograph projectors. COMMUNITY SERVICE, Ltd., 1, Montague Street, Russell Square, London. Jan. 22, 1934, No. 2201. Convention date, Jan. 23, 1933. [Class 97 (i)] [See also Group XXXVIII] A projector comprising sound-reproducing means has means for automatically threading and placing the film into full operative relation with the film-engaging members, means for rendering the sound-reproducing means operative and inoperative, and a common control device for both such means. As shown in Fig. 1, the apparatus comprises a pay-out spool 10, carried by a bracket 8, from which the film passes through picture and sound gates, 112, 113 respectively, and by way of continuous-feed sprockets 12, 14, 15, and an intermittent sprocket 13, to a take-up spool 25. Sprocket shields 40, 55, 58, 60, film guides 46, 57, 62, loop-forming members 165, 166, 167, pressure members 30, 33, 34, 35, take-up guide members 131, 136, and the movable gate sections 110, 111 are all controlled by a device comprising a shaft 268 carrying a number of cam discs and rotatable by a knob 270. The knob 270 is rotatable to positions indicated by the markings S0 .... S4; in position S3 hand threading is possible, in position S0 automatic threading is effected, in position S2 film loops are formed, and in positions S1 and S4 projection and rewinding respectively occur. Shutters 251, 253 respectively shield the picture and sound gates from the light from lamps 114, 117 in all positions except projecting position, and are automatically controlled by operation of the knob. Fig. 2 shows the positions of the film-contacting parts during hand threading and rewinding, the gates being open, the pressure members spaced from the sprockets, the sprockets covered by their shields, and the guides and loop-forming members being in position to provide a clear film passage. Movement of the knob 270 from hand-threading position S3 to re-winding position S4 does not affect the position of these members, but is effective to operate a clutch through a cam on the shaft 268 to place the spindle of the pay-out spool into driving connection with the motor. Each sprocket shield comprises a body 40, Fig. 11, having a stripping extension 41, and is mounted on a collar coaxial with the sprocket and carrying a gear meshing with a vertical rack 44 moved by a roller 51 in a cam slot 52 in a disc 53 rotated with the shaft 268. The guides 46 &c. rotate with the shields, but are connected to them in a manner permitting of slight relative movement when movement of the knob 270 into hand-threading position, after projection, renders such movement necessary to avoid damage to the film loops. The film channel is somewhat narrowed for automatic threading, and the movable gate members 110, 111, and the presser members 33, 34, 35, are carried by a member 123, Fig. 7, controlled by a cam disc on the shaft 268, to effect the necessary movement when the knob 270 is moved to position S0. This movement of the knob 270 also causes a pivoted lateral film guide, extending the full length of the channel, to be turned into operative position, causes the rollers of the presser member 30 to engage the shield 40, and effects a driving connection to these rollers so that the film, the end of which has been previously inserted between the rollers and shield, is fed through the channel to the takeup spool. Attachment of the film to the takeup spool 25 may be ensured by a fixed guide 130 and by the pivoted guides 131, 136 which are automatically closed upon the spool as the knob is moved to position S0, and move slowly from it, when attachment has been effected, under the control of a dash-pot. The apparatus may be modified so that the film is fed through the channel by means also of the rollers of the other presser members, such rollers being driven in addition to those of the member 30, or so that the film is driven by the pay-out spool. Movement of the knob 270 from position S0 to loop-forming position S2 is prevented by an automatic locking means until completion of the attachment of the film to the spool 25 has been effected. The movement, when made, causes the loopforming members 165, 166, 167, Fig. 7, which are carried by a plate 168 controlled by a cam disc 172 on the shaft 268, to move across the film channel thereby drawing film from the pay-out spool, over the sprocket shields, and forming the loops. They subsequently move slightly further, to draw the film on to the sprockets, when the sprocket shields are moved from the shielding positions. When the knob is moved to position S1 the parts are all moved into projecting position, Fig. 1, and driving connection to the projector motor is established. This movement also causes the shaft 252 carrying the shutters 251, 253 to be turned so that the light beams are no longer cut off. The motor circuit and the light circuits may be controlled by the control device. The mechanism whereby the operation of the control knob effects the necessary movements of the parts of the apparatus is described in detail in the Specification. Specification 258,264, [Class 97 (i)], is referred to.