Patent GB-203367-A (GB)
Title: Improvements in or relating to the manufacture of photographic films
IPC: G03B27/16
Filed: 1922-05-04
Abstract: 203,367. Wade, H., (PathÚ Exchange, Inc.). May 4, 1922. Printing-apparatus.-Relates to apparatus for determining the printing light to be used for a kinematograph film in which short lengths f superposed negative and positive films are moved together over a light opening in which the printing light is varied, as the individual pictures pass said opening, by means of resistances inserted in the light circuit. A frame D<1>, Figs. 1 and 2, on a platform A, has a slot above the printing light E and guide ways for a travelling carriage J which has a slotted plate J‹ and a door M hinged at M<2>. The negative film B<1> is threaded over rollers j, j<1> journaled on the travelling carriage J, and lies on the plate J‹, while the positive film C<1> passes under rollers m, m<2>, t<1>. and over the feeding roller T‹, all journaled on the door M so that the negative and positive films are superposed when the door M is closed down but are. separated when the door is opened. The back of the door M has a smooth plate m<1> or a pad of rubber or felt to produce good contact of the two films. The travelling carriage J can be moved to the right either by hand by the wheel Q<2>, on the shaft Q<1> which has a pinion engaging with a rack on the carriage, or by power driven means connected to the pulley S<3> when the clutch R is in the position shown in Fig. 1. The return stroke is produced by a weight K, Fig. 4, connected by chains X passing over pulleys K<2> to the travelling carriage. Arrange] on the platform A is a line of contact strips g<1> and a conducting strip g, and a. bridge H, fixed to the carriage J, has contacts h, Fig. 6, which contact with the strips g, g', so that as the carriage J moves to the right the resistance, G' in the printing lamp circuit will be varied for the successive pictures. The carriage J is stopped automatically by the standard 0 striking the screw r<4>, on a pawl R<6> pivoted at r<3> so as to disengage the catch r<1> with a lock r<2> on a lever R' pivoted at r, whereupon the compressed spring R<4> on the rod R<2> disengages the clutch R with the driving mechanism. The door-hinges M<2> have springs M<1> which tend to keep the door M in the open position as shown in Fig. 9 and the door is kept closed by a spring-catch N, Fig 6. When the series of pictures are printed the door M is opened automatically by a roller n on the latch N engaging a cam V on the platform A, and the door is retained in the open position by a spring catch P. Buffer springs 0<2> take the shock of the door opening. When the door is in the open position a pinion T<2> on the spindle of the feeding pinion T‹ engages, a fixed rack T, so that. as the carriage. J returns to its initial position under the action of the weight K, the feeding pinion T‹ rotates and feeds forward another length of positive film. A fresh section of the film to be tested is then wound up by hand. A shock absorber L stops the carriage J at the end of its return stroke. Aprons K<4> connected to each end of the travelling carriage J pass over pulleys K<5> and are kept taut by weights X'. These aprons prevent the negative film from getting scratched on the frame D. The printing light E and red light F are preferably arranged as shown in Fig. 8 and the switch I is operated by the lever R<1>. When the lever @ is as shown in Fig. 1 the red light is short circuited and the printing light E is illuminated. When the lever R<1> is as shown in Fig. 9, current passes through both red and printing lamps, but as the red lamp is of low amperage compared with the printing lamp the former is illuminated and the latter extinguished.