Patent GB-1391527-A (GB)
Title: Photographic camera
IPC: G03B17/42
Filed: 1972-05-11
Abstract: 1391527 Camera mechanisms EASTMAN KODAK CO 11 May 1972 [11 May 1971] 22183/72 Heading G2A In a film transport mechanism the movement of the film is metered by a pivotally and displaceably supported sensing member 5 having a nose 5b which can engage in a perforation 12a in the film 12, and as it is carried along by the film a rear projection 5a of member 5 slides along an arm 3e of a lever 3 until it has cleared this arm, upon which nose 5b is withdrawn from perforation 12a and simultaneously allows the film transport to be blocked. As shown, the film advance is effected by a member 1 sliding in the direction C. A notch 1c entrains a lug 13a of a rack 13 which drives a gear train 14, 25 and hence a film take-up reel 15. Thus as member 1 moves in direction C, the film is wound on to reel 15 in direction F. Fig. 1 shows the initial position of the mechanism, preparatory to a film advance movement. A cam surface 1a of the advance member 1 is engaged by an ear 2b of a drive lever 2, and so maintained by a spring 4. A control lever 3 has an arm 3a which is maintained in contact with an arm 2a of lever 2 by a spring 9. The sensing member 5, mounted so that it can both pivot and slide on a pin 11, is maintained in the position shown by a spring 8. As the advance member 1 is moved in direction C, and the film 12 is wound on in direction F, lever 2 is pivoted clockwise by cam 1a, which allows lever 3 to pivot anti-clockwise. Arm 3e engages under projection 5a of member 5 and pivots the member so that its nose 5b is brought into contact with the film, and rides along it. When a film perforation 12b reaches nose 5b, member 5 pivots still further, so that the nose enters the perforation. As the film moves on, member 5 is drawn with it to the left, because of its pin and slot mounting 11, 5c, and during this movement projection 5a slides along arm 3e. When projection 5a has drawn clear of arm 3e, Fig. 3, lever 3 is movable to pivot still further anticlockwise until another arm 3b comes into locking engagement with teeth 1b on the lower edge of advance member 1, so preventing any further movement. Drive lever 2 has now been pivoted into the position shown by cam 1a, which cocks the shutter. As member 1 is released, it is returned to its initial position by spring 18. Lever 2, however, is retained in the Fig. 3 position by means not shown, and a clutch provided between gear 25 and reel 15 enables the gear to rotate backwards without the film moving. During the movement of the parts of the mechanism from the Fig. 1 to the Fig. 3 position, an arm 3d on lever 3 has blocked the line of movement of the shutter release member 10, so that this cannot be actuated inadvertently. However, as lever 3 completes its anti-clockwise movement, arm 9 is brought clear of member 10, so that the shutter release can now be actuated. This also releases lever 2, which is drawn rapidly from the Fig. 3 to the Fig. 1 position by spring 4. In doing so it strikes lever 3, pivoting it clockwise, so that it is free of member 1 and once more blocking release member 10, and also arm 3e again engages under projection 5a. When there is no film cartridge in the cartridge chamber 17 a lever 6 is drawn by a spring 7 into the position of Fig. 4 (not shown) in which a pin 20 at one end moves lever 3 out of alignment with release 10, so that the film advance and release can still be actuated. When a cartridge is present, the lever 6 is moved to a position in which it has no effect, as in Figs. 1 and 3.