GB906495A - Improvements in or relating to photographic cameras - Google Patents

Abstract

906,495. Photographic cameras. HEIDECKE, R., and FRANKE, H., [trading as FRANKE & HEIDECKE FABRIK PHOTOGR PRAZISIONS-APPARATE]. Feb. 10, 1959 [March 29, 1958], No. 4591/59. Class 98 (1). In a roll film photographic camera having a film feed limiting mechanism adjustable to alternative film formats, said mechanism comprises a plurality of notched coaxial discs driven by a film metering roller and each having a different notch spacing corresponding to one of said film formats, a latch adjustable axially of said notched discs and actuable to engage successively in the notches of that disc corresponding to a selected format and film wind means including a lock coupled to said latch and operable to interrupt the film feed upon engagement of the latch with a notch in the said disc. As shown, detent discs 2, driven by a metering roller 5 through gears 3 and 4 and toothed counter disc 1, are alternatively engageable by a detent latch 26 on a lever 25 pivotable about a hinge 24 on a lever 14. Change-over of the latch from one disc to another is brought about by a pin-and-slot connection 59, 60 when a slide 58 is move up or down. At the same time, a window 61 in the slide 58 is moved into registration with the corresponding annular series of numbers 67 or 68 on the counter disc 1 rigid with the discs 2. Automatic changeover of latch 26 so as to correspond with the format in use, is obtained through movement of a spring- urged pivoted lever 62 coupled at one end through a pin-and-slot connection to the slide 58 and coupled at the other end-also by a pin- and-slot connection-to a feeler lever 63, which adjusts itself under loading of spring 65 to the size of format mark 66 in use. In place of this automatic change-over the slide 58 may be adjusted manually (by means, not shown), in which case a pin 56 on the camera back 12 may be provided engageable with one or other of holes 57 to prevent unintentional movement of the slide 58. Lever 14 which is pivotable about a pin 13 and is urged by a spring 15 in the anticlockwise direction, bears a pawl 16 cooperating with a toothed wheel 17 to act as a film-feed lock. The film-feed mechanism comprises a feed crank 21 coupled to a take-up spool driving gear 20 by way of a one-way acting clutch 22, 23 and gear-wheels 18 and 19, (wheel 18 being rigid with wheel 17). Operation of the camera is as follows. When the camera back 12 is opened, a slide 10 is moved to the left under loading of a spring 11, whereupon a lug 39 thereon engages a bevelled surface of the lever 14 and disengages the feed-lock pawl 16 from the wheel 17 and the latch 26 from one or other of the discs 2. At the same time, gearwheels 3 and 4 which are mounted on a spring- urged lever 7 pivoted at 8 are moved to the left by reason of the coupling 9 between lever 7 and slide 10 and the counter disc 1 is freed to return under spring-action (not shown) to its zero position. Upon re-closing the back 12 the gear-wheel 3 is re-engaged with disc 1, but the feed-lock pawl 16 is held inoperative by the engagement of the latch 26 wth the periphery of one of the discs 2. Film may then be advanced by rotation of crank 21 until latch 26 engages with the first notch in disc 2. Reverse rotation of crank 21 during this operation is prevented by means of the co-operation between a spring-urged pawl 42 and a ratchetwheel 41 rigid with the crank. Upon the locking pawl 16 operatively engaging with toothed wheel 17, the pawl 42 is rendered inoperative (cf. position in Fig. 2) by the engagement of an arm 45 of the lever 14 with a lug 46 thereon. The crank 21 may then be returned to its rest position, this position being determined by the engagement of a spring-urged pawl 47 pivoted on ratchet-wheel 41 with the pawl 42. The crank 21 then becomes jammed in this position with pawl 47 engaging a lug 52 on the ratchetwheel 41-until released by the shutter as described below. The shutter setting ring 37 with associated cocking lever 36 is automatically cocked during film-advance as a result of a pin 34 rigid with the crank 21 engaging with an arm 33 of a spring-urged lever pivoted at 32 and coupled through a pin-and-slot connection 30 with an arm 35 rotatable about the between-lens camera shutter and engageable with the cocking lever 36. During the final running-down movement of the shutter, the lever 36, by way of coupling link 28, pivots the lever 14 in the clockwise direction, and thereby releases locking pawl 16 and pawl 42, whereby the film may again be advanced. A lever 48 pivoted at 49 and bearing pins 50 and 51 is provided so that the pawl 42 may be optionally disengaged from the pawl 47.