Patent GB-633489-A (GB)
Title: Improvements in or relating to photographic projection printing apparatus
IPC: G03B27/475
Filed: 1946-12-20
Abstract: 633,489. Photographic printing apparatus. KODAK, Ltd. Dec. 20, 1946, No. 37582. Convention date, Jan. 12. [Classes 97 (i) and 98 (i)] [Also in Group XXIV] In apparatus comprising a projector through which a film strip is moved intermittently to bring successive image-bearing areas thereof into a projection printing position, a camera through which a light-sensitive film strip is moved intermittently to record the imagebearing areas and a clutch between the projector driving mechanism and the camera driving means to enable the two strips to be moved in unison, a clutch-operating member is manually adjustable relative to control means operated by the camera driving means to any one of a number of predetermined positions in which the control means causes the clutch-operating member to interrupt the actuation of the projector driving mechanism for different periods of time determined by the number of prints required of an image-bearing area. As shown, a shaft 29, Fig. 7, driven by the sensitive film driving mechanism, is connected by a clutch to a shaft 31 driving the original film feed mechanism. The clutch consists of a helical spring 47 tightly embracing sleeves 41, 44 fast with shafts 29, 31 respectively and fastened at one end to the sleeve 44 at 48 and at the other to a bar 52 carried by a disc 50 freely mounted on the sleeve 44. The clutch is operative when the disc 50 is free to rotate, but inoperative if the disc is held against rotation, as by a pawl 55, Fig. 6, on a spring-urged plate 56 entering one of four peripheral notches 54. A drum 40 rotatively mounted on the sleeve 41 is driven by the shaft 29 through reduction gears 35, 36, 38, 39 and carries peripheral rows of pins 62. An arm 65 pivots on a shaft 64 and carries a roller 66 engaging the drum surface. As the drum rotates, the arm 65 is raised as the roller 66 rides over the pins 62, raising the arm 56 to free the pawl 55 from the notch 54. The clutch is then engaged and the shaft 31 is driven until the next notch 54 is engaged by the pawl 55, in which time the original film is advanced one frame. During the period before the next engagement of the pins 62 with the roller 66, the sensitive film only is advanced and several prints are made of one frame of the original film. The number of prints made depends on the number of pins 62 in the row engaged by the roller, which may be made to engage any row by sliding the arm 65 along the shaft 64 by a finger-piece 86. The plate 56 extends parallel to the drum axis to engage the arm 65 in any position. Locating means for the arm 65, and a scale indicating the number of copies made of one frame, are provided. A bar 75 guided to move longitudinally parallel to the drum axis bears a similar scale and is located by a spring-urged arm 80 entering notches therein, and carries a finger-piece 84. For quick adjustment, the bar 75 is set for the required number of frames and the fingerpieces 84, 86 brought into registration. The roller 66 may in one setting engage a part of the drum surface such as at 89 having no pins, so that the sensitive film only moves, and in another setting may engage a raised portion 90, lifting the pawl continuously, so that both films move in unison.