Patent GB-589883-A (GB)
Title: Improvements in or relating to a motion picture printing apparatus
IPC: G03B27/16
Filed: 1945-02-21
Abstract: 589,883. Kinematograph printing apparatus. KODAK, Ltd. Feb. 21, 1945, No. 4359. Convention date, March 18, 1944. [Class 98 (ii)] The apparatus has means for moving a film to be printed past an exposure aperture to which a constant intensity printing light is admitted through a diaphragm capable of being adjusted to vary the quantity of printing light supplied to the film by mechanism comprising a plurality of levers pivoted to the apparatus and selectively operable for engaging and moving one of a plurality of arms radially extending from a rock-shaft along which they are axially spaced and angularly off-set relative to one another, and a pair of arms which are operated by movement of the rock-shaft to adjust the diaphragm to a size depending upon which of the radial arms is engaged and moved by the corresponding lever, said levers being operated one at a time during the film movement in an order determined by the light intensities selected for printing different portions of the film. As shown, the light source 66, - Fig. 4, is mounted in a housing 59 with a removable cover 61 having an aperture 63 through which light from the source is reflected by a prism 76 on to a pair of films fed'over a sprocket 64 and guide-rollers 65 for contactprinting. Pivoted at 69 in the housing are two levers 70 carrying diaphragm blades 72 in the light path, and connected together by a spring 75 tending to widen the diaphragm aperture. Links 80 connect the levers 70 to a crank-arm 79 on a shaft 78 journalled in the housing and carrying four arms 81 spaced along, and set at different angular positions on, the shaft 78. Above this shaft are four levers 83 pivoted on a shaft 85 journalled in the housing so that each rests above one of the arms 81. Each lever is provided with a pair of adjustable screws 97, Fig. 6, whose heads co-operate with the spear-head 82 of the corresponding arm 81 when the lever is depressed and cause the arm to assume the vertical position, thereby through the links 80, 70 adjusting the diaphragm plates 72 by an amount corresponding to the initial setting of the arm 81 concerned. For selectively depressing the levers 83 according to the density or the film section to be printed, each is linked to the armature of one of four solenoids 25 which are selectively actuated from notches made in the edge of the negative film by pre-set means shown in Figs. 2 and 3, comprising a housing 15, Fig. 2, containing a fixed plate 16 provided with four conductor rings 18 and an adjacent parallel fixed plate 17 having a ring of contact studs 19 and radial slots 20 in any of which may slide a finger 21 coupling one of the studs 19 with one of the conductor rings 18. Over the studs 19 travels a contact arm 30 on a shaft 52 carrying a ratchet wheel 5 adapted to be displaced to move the arm 30 from one stud to the next by a pawl 49 pivoted to the armature of a solenoid 39 which is actuated by a battery 28, Fig. 3, when the plunger 35 of a micro-switch 34 in circuit therewith enters a notch 11 in the edge of a film 12. The four conductor rings 18 are connected to one pole of the battery 28 through the four solenoids 25, Figs. 3 and 4, and the shaft of the conductor arm 30 is connected to the other pole through a cut-out switch 33. Thus, according to the pre-set position of the finger 21 beneath any particular stud 19, one or other of the solenoids 25 is energized to operate the corresponding lever 83, Fig. 4, and make the necessary adjustment of the diaphragm plates 72. If the contact arm 30 rests on a stud which has not been connected by a finger 21 to one of the conductor rings 18, none of the solenoids 25 is energized, and the spring 75, Fig. 4, opens the diaphragm to its widest extent, thereby providing a fifth variant. Manual adjustment of the conductor arm 30 may be effected by a knob 56.