Patent GB-770609-A (GB)
Title: Improvements in or relating to a motion picture camera
IPC: G03B19/18
Filed: 1955-06-20
Abstract: 770,609. Kinematograph cameras. KODAK, Ltd. June 20, 1955 [June 21, 1954], No. 17750/55. Class 97(1) A camera comprises a spindle for receiving a supply roll of film and a take-up core, each movable between a normal or running position and a film threading position, a film guideway which, when the supply spindle and take-up core occupy their film threading positions, extends from a position adjacent a supply roll of film when positioned on said spindle to a position adjacent the take-up core, said film guideway including a film gate, means on said take-up core for engaging the leading end of a film fed through the guideway and for attaching said end to the core, means for moving said core to the normal running position when said supply spindle is moved to its running position, and means for simultaneously forming free film loops in advance of and beyond said film guideway. In the form shown in Fig. 1 the invention is applied to a camera in which the two longitudinal halves of the film are exposed in succession. The film drive is stopped automatically after the exposure of the first half. A spring loaded plunger 18 is then retracted and an arm 15, carrying a view finder member 16 and mounted on a rotatable ring 14, is turned through 180 degrees when the plunger is engaged in a hole 94. The camera is then inverted, the rear viewfinder member 17 being movable to correspond to the new position of the front member 16. Rotation of the member 14 has effected all the necessary internal adjustments to the camera wherebv the second longitudinal half of the film may be exposed-the direction of film feed is reversed and a masking plate is moved to uncover an exposure aperture appropriately aligned with the film. The ring 14, when rotated, carries with it the release lever 19 which engages with a pivoted lever behind the plate 221, in both extreme positions of rotation of the ring to effect release of the camera drive. The lens mount 13 is carried on a lever pivoted behind the plate 221 and moves in a slot in the plate covered by the disc 225 so that the pivoting movement, which is effected by the rotation of the ring 14 by cam surfaces on the inner face thereof, produces a lateral movement of the lens to align it with the appropriate half film width as indicated by the dimension A. The running out of the film at the end of the winding for exposure of the second longitudinal half releases a film edge feeler to latch the plunger 18 in the hole 94. The arm 15 is thus locked in a position which permits the cover 24 to be opened, the film spool 28, Fig. 3, to be removed and a fresh film threaded. The spindle of the spool 28 is carried on a bracket 25, pivoted at 26, which also carries the cover 24 and a film guide 69. A guide 71 is spring urged outwardly into contact with the outer convolution of film. The film end may thus be pushed between the guides 69 and 71, into a channel 57, past the gate towards a take-up core 33 carried at the end of an arm 34 pivoted at 35 and spring urged to the position shown. The core carries a pair of spring bands 43, each encircling half the circumference of the core and having an outwardly flared end 45. The core carries driving dogs which, in the position of the arm shown, strike a fixed abutment which positions the core so that the film end is fed under one of the spring ends 45 where it is retained by an inwardly projecting tooth. It is subsequently removed from the tooth by film tension during rewinding, the outward movement of the spring being limited by a hooked end 49 engaging an abutment in the core. The cover 24 is then closed. The film is thereby led round the roller 84 and a clutch member on the spool spindle, carrying a driving dog 30, is brought into line with the driven pulley 154 carrying a driving dog 163. The end 55 of the bracket 25 strikes the end 54 of the lever 34 to swing the take-up core into alignment with a driven pulley 153 carrying a driving dog 162 the film being led round a roller 53 At the same time the end 68 of the guide 69 bears on a spring 67 to apply pressure to a presser pad at the film gate. The pulleys 153, 154 drive the spool or the core 33 alternatively, as required to produce the appropriate direction of film feed, through holes in the wall 21 behind which the driving mechanism is situated. The pulleys 153, 154 are driven in opposite directions by a twisted belt from a single pulley 152, Fig. 19, driven by the spring motor M. The pulleys are mounted at opposite ends of a lever 157 mounted on a shaft 159 which carries a spring 166 the ends 164, 165 are engaged alternatively by abutments 260, 261 carried at the ends of fingers 257, 258, Fig. 18, which form part .of a slide 252 actuated by means, not shown, coupling it to the movement of the ring 14. Movement of the slide therefore produces the necessary reversal of direction of the film spool drive. Rotation of the ring 14 is also coupled to the sliding plate 105. Fig. 25, which is apertured to produce the necessary film masking adjustment at the gate and also has a slot 131 through which one end of the double ended reciprocating claw 125 engages the perforations in the film F. The other end of the claw rides on the face of the plate 105. Longitudinal movement of the plate renders the latter end of the claw effective and the former ineffective. The slide 252 also co-operates with a pivoted lever 200, Fig. 21, which is actuated by a pin 208 on a ratchet wheel 192 rotated by a pawl on an arm 194, see also Fig. 18, oscillated by a cam on the main spring drum, hot shown. The ratchet wheel 192 is geared to a film feed indicator disc 187. The lever 200 is pivoted at 201 and is acted on by a toggle spring 202. When the first half of the film has been exposed the pin 208 strikes the arm 210 of the lever 200 to move the lever to the position shown in Fig. 21. This causes the hooked end 206 of the lever to engage a pin 174 mounted transversely in the governor shaft of the spring motor, not shown. This stops the motor even if the release lever 19, Fig. 1, is still depressed. The movement of the slide 252 causes the finger 259 to engage the spring anchorage 204 to move the lever 200 sufficiently to free the pin 174. As the motor is run to expose the second half of the film the ratchet 192 rotates until the pin 208 strikes the arm 209 so that the lever swings until the end 211 strikes a member 136 which is part of the frame to which the feed claw is pivoted. The frame is reciprocated longitudinally on pins to .produce the feed movements and is rotated about the pins by the end 211 of the lever 200 to retract the claw from the film for threading a fresh film. The driving motor has a centrifugal governor with a disc 175, Fig: 18, engaged by a brake shoe 177 on a slide 178 adjusted by a cam 179 actuated by a speed setting device with dial 181.