Patent GB-882966-A (GB)
Title: Improvements relating to photographic apparatus
IPC: G03B17/52
Filed: 1960-02-25
Abstract: 882,966. Photographic film-feeding apparatus. INTERNATIONAL POLAROID CORPORATION. Feb. 25, 1960 [March 6, 1959], No. 6681/60. Class 98(1). In photographic apparatus wherein continuous sheet material is passed, a stop, arranged for engaging and disengaging respectively to arrest and release the material, can, when in its engaging position, be prevented from engaging the material by displacement of the latter away from the stop under the influence of a movable control member extending beyond the stop in one position and movable, by frictional engagement with the moving material into a second non-operative position to allow the stop to engage the material, the stop being disengaged therefrom by the operation of an actuating mechanism which also allows the return of the movable control member to its operative position. In the camera shown in Fig. 1 a positive material film 40 carrying rupturable containers of developing liquid 42 can be drawn together with negative film 30, which has been exposed at the aperture 24 of the camera, between rollers 52 and 54 to rupture the containers and allow the liquid to spread so that diffusion transfer takes place under the roller pressure and the print can be removed through channel 58 and cut by the cutter 60 which serves also to cover channel 58. The film 40 has pairs of marginal apertures (not shown), at intervals corresponding to the film size, which can be engaged, so as to arrest the film by a pair of pins 76 carried on a resilient member 78 secured at its mid-point to the back (i.e. remote from the film) of a supporting plate 70 having arms 72 pivotally mounted between the side-walls of the camera at 74 and biased counter-clockwise thereabouts by spring 88 attached to a lug 86 carried on a fixed guide plate 66 which has apertures through which project pins 76 and further apertures 116 for projection therethrough of cam members 108, pivoted on a shaft rigid with 70, and biased by torsion springs in a clockwise direction to rest against the support 70 as in Fig. 1. Under the bias of spring 88, pins 76 bear against the film 40 and would on movement thereof eventually enter the marginal apertures. However, the downward movement of the film carries with it, by frictional engagement, the cam surfaces 108 in counter-clockwise rotation against their spring bias and these cam surfaces having a maximum radial extension greater than the length of pins 76, displace the film towards the front of the camera clear of pins 76 until the latter are correctly aligned with the apertures in which position the operative cam radius is such as to allow engagement of the pins with the apertures. To disengage pins 76 from the apertures, the sector shaped lever 100, rigid with a sharply-angled spring- loaded cam 94 and pivoted about 97, is turned clockwise whereby the apex of the cam 94 acts momentarily on a pin 92 carried on the support member 70 to deflect the latter rearwardly and clear of the film, thus allowing cams 108 to return under their spring biasing to their rest position of Fig. 1 whereby they are so disposed as to be once again operative in holding the film 40 out of range of 'pins 76 on the forward movement of the latter under the action of spring 88 as the apex of cam 94 comes out of contact with pin 92, in order that there shall be no re-engagement of pins 76 with the apertures they have just vacated so as to allow further movement of the film. Specifications 684,592, 689,892, 714,412 and U.S.A. Specification 2,843,029 are referred to.