Patent GB-935324-A (GB)
Title: Camera
IPC: G03B17/42
Filed: 1962-04-16
Abstract: 935,324. Roll-film cameras. WHITEHOUSE PRODUCTS Inc. April 16, 1962 [May 1, 1961], No. 14572/62. Class 98 (1). A roll-film camera has a film-metering wheel rotated by peripheral engagement with the film; two pawls are mounted on a common pivot, one spring-urged into engagement with a notch in the metering wheel, the other spring-urged into engagement with a ratchetwheel on the film-winding mechanism, so that both pawls thus exert a locking action; the pawls can bear one against the other, so that when the first is disengaged, the second becomes disengaged also. The camera shown is of the type in which the film spools are mounted on a separate cartridge or magazine, insertable into the camera body. The film winds from a supply spool on to a take-up spool mounted on a shaft 6 which is rotated to advance the film. As it advances, it bears against the rubber rim 16 of a metering wheel 13; the dimensions are such that when the wheel makes one complete revolution the amount of film required for one picture has been advanced. The first pawl 18, pivoted at 19, has an upturned end 20 which rides along the periphery of wheel 13 until it enters a notch 21 therein. The second pawl 31, also pivoted at 19, has an upturned end 32 which can engage in the teeth 30 of a ratchet wheel 29 fixed to shaft 6. A downturned tab 36 on the second pawl engages against the first pawl. Thus as first pawl 18 rides along the periphery of wheel 13, it also holds second pawl 31 out of engagement with ratchet wheel 29, so permitting film advancement to take place. When the right length of film has been advanced, pawl 18 latches into notch 21, allowing pawl 31 to engage the ratchet teeth, thus locking the film advance. After a picture has been taken, the pawls are disengaged, to allow a further film advance, by a lever 37, which is released to move counterclockwise under spring action, by a cocking slider 46 moving to the right (Fig. 1). This cocking slider is mounted on a square shaft 98, and by means of a slider and cam mechanism (Fig. 2, not shown) is moved to the left in Fig. 1 (i.e. to the right in Fig. 3) to cock the shutter when the film advancing shaft 6 is rotated. In so moving (i.e. to the right in Fig. 3) it engages a lever 88 pivoted at 89, and turns it counterclockwise against a spring loading, so tensioning the shutter blades 90. Lever 88 is retained in this cocked position by a latch 110 engaging in a hole 111 in the lever. The exposure is made by pressing a release button 118, which pivots a lever 120 to rotate shaft 98 slightly. This causes latch 110 to retract and release lever 88, which turns clockwise under the action of its spring 92 and actuates the shutter blades. At the same time the cocking slider is released to move to the left (Fig. 3) under the action of spring 105. This movement of the slider, acting through lever 37, rotates pawls 18 and 31 out of engagement with their respective wheels, so allowing a further film advance. In order that the pawls may be disengaged while the leader-trailer strips are wound on, a rod 50 is provided. This is actuable from outside the camera by a handle 57, and when the rod is drawn across to the right (Fig. 1), a vertical portion 51 engages against the pawls.