Patent GB-1080923-A (GB)
Title: Film spools and automatic projictors
IPC: G03B21/43
Filed: 1964-08-06
Abstract: 1,080,923. Cine protectors; spools. COMPAGNIE D'APPLICATIONS MECANIQUES A L'ELECTRONIQUE AU CINEMA ET A L'ATOMISTIQUE (C.A.M.E.C.A.). Aug. 6, 1964 [Aug. 6, 1963], No. 32043/64. Headings G2E and G2J. A self-threading cine apparatus, such as a projector, has a supply spool 12 whose circular cheeks 24, 25 each have an inner peripheral groove 26 which releasably holds at any point a clip 27 attached to the free end of the film wound on the spool, and transfer means by which the clip on spool 12 is automatically stopped at a predetermined position and is then detached from between cheeks 24, 25 and passed through a notch 114 in the upper cheek of the take-up spool 9 which has also been stopped at a predetermined position. The beam from projector B is directed by mirrors C, D, on the screen E. Clip 27 has projections 28, 29 which enter grooves 26, the cheeks 24, 25 being clamped together by wing portions on the clip. The filled supply spool 12 is placed on spindle 33 and lever 34 is rotated clockwise to actuate switch 35 to start the motor driving spools 12 and 9 through pulley 1 and belts 1', and 1", lever 34 being held by lever 39. As spool 12 rotates, clip 27 rocks lever 39 to release lever 34 and so stop the spool and to actuate switch 40 which starts motor 41 driving shaft 43. Cam 44 rotates to operate push-rod 50 and lever 51 to allow pin 53 of the transfer arm 13 to enter bore 31 of clip 27, further rotation of cam 44 causes its lug 48 to abut extension 49 of arm 13 which is then set in motion. Arm 13 detaches clip 27 from spool 12 rotates the meet stop 56; cam 57 on pinion 42 then stops motor 41 through contact 58. Spool 9 was previously set with latch 55 in notch 114 and clip 27 is therefore able to enter space 111 to the centre of the spool. Lug 179 on arm 13 catches lever 61 whereby locking levers 55, 65 and 71 are rocked to unlatch spool 9 for initial slow-speed winding until film tension is sufficient to rock pawl 63 by means of a rod 69 radial to the spool and actuated by depression of a pin projecting from the hub of spool 9. Lever 71 is released by pawl 63 to stop the projection motor and operate motor 74 whereby arm 5 is turned anti-clockwise to press the film between movable rollers 76 on the arm and fixed rollers 75. The film now engages sprocket 4, gate 2, and sound head 3. Notch 74 is stopped when lever 81 reaches contact 82, and projection starts at full speed, the spools being driven against friction clutches such as 37. After projection ends a pin enters perforations in the end of the film and bar 22 engages bar 23 to reverse the motor through contact 83, and loop-forming arm 5 is swung away so that spools 9 and 12 take up the loops. Arm 5 moves lever 86 whose shoulder 186 engages the lug 187 of lever 85 whereby roller 14 contacts edge 96a of the plate 96 supporting spool 12, so that driving roller 131 drives the spool in reverse. After re-winding film tension falls and the other end of rod 69 trips lever 61 to release lug 179 on arm 13. Rocker 88 is pivoted by lever 65 and raises pawl 86 through push-rod 87, whereby roller 14 is disengaged from plate 96. Lever 62 then moves roller 90 into slow-speed driving contact with the cheek of take-up spool 9 to unwind the final turn of film leader. Latch 55 then enters notch 114 to immobilize spool 9 in the initial loading position, and to disengage roller 90 from the spool while closing switch 92. Motor 41 is thus reversed to return arm 13 to its initial position against stop 46, the rotation of spool 12 maintaining film tension; clip 27 is then re-engaged with cheeks 24, 25 of spool 12. Further rotation of shaft 43 retracts pin 53 through cam 44 and pushrod 50 and liberates the clip. Cam 59 then stops motor 41 and the projection motor.