Patent GB-790005-A (GB)
Abstract: 790,005. Photographic processing apparatus. DEAJAC PRODUCTS, Ltd. Aug. 9, 1955 [Aug. 9, 1954], No. 18554/55. Divided out of 12972/53. Class 98(2) [Also in Groups XXXV and XXXVII] Timing mechanism for controlling a sequence of operations such as the transfer in sequence of a succession of photographic films to be processed through a series of tanks containing developing and like solutions, comprises a perforated tape 1 mounted on rollers 3 and passing through a guide-way 5, 5<SP>1</SP>. A succession of steel balls 6 in an inclined reservoir 7 are dropped one at a time into the guide-way when a spring- biased detent 9 is operated by means of an electromagnet, so that a released ball lodges in a perforation in the tape and travels along the guide-way to be discharged into the upper end of the reservoir 7. In its passage, the ball actuates micro-switches 11-14 in succession, a further switch 15 being provided in association with the extension 5<SP>1</SP> of the guide-way. The tape is advanced in equal steps, each equal to the distance between adjacent perforations, by means of pawl 17 engaging a perforation and actuated by an oscillatory arm 18 driven by a rotatable cam 20. A suitable dispositoin of the micro-switches permits them to be operated at desired time intervals. Alternatively, an endless chain passing over sprockets may be used in place of the tape 1. In another arrangement, the carrier comprises a perforated disc rotatably mounted on a horizontal axis, front and rear guide plates being mounted adjacent to the disc to retain the balls or other markers in the recesses. A shoot removes each marker from the upper portion of the path and leads to means for sequentially supplying markers to the carrier disc. In a further modification, the carrier disc has regularly spaced projections and each marker is adapted to fit over any of the projections. According to another method, the carrier is a flat magnetic member, such as a steel disc with a horizontal axis, and each marker is a magnet. Apparatus in which the timing mechanism may be used comprises a number of tanks 1-4 containing, respectively, developing, washing, fixing and washing solutions, it being desired to pass a succession of exposed films or plates through the tanks and to immerse them for pre-determined periods. Electric motors 6 drive endless chains 8 having carrier bars from which depend frames upon which a film is adapted to be detachably supported. Rollers on the sides of the frames engage ramps 11, and each carrier bar has cradles which engage under studs on the frames whereby each frame is picked up when it is at the end of a ramp 11 and released after it has been lifted up one side and down the other of a chain 8 by engagement of a roller on the higher end of the next successive ramp. The electric motors are sequentially controlled by means of stepping switches, Fig. 5 (not shown), each arranged to energize its assicated motor upon receipt 'of a pulse from the timing mechanism so that a frame is picked up and deposited in the next tank, a projection on the chain operating a switch which sends a second pulse to the stepping switch to de-energize the motor upon deposition of the frame. The cradle is now in position to pick up the next frame upon receipt of a further pulse from the timing mechanism. The ball release mechanism of the timer is operated by means of switch 24 when a frame is placed on the first ramp. Electric heating elements are fitted in tanks 1, 3, which also have level in'- dicator lamps and means for automatically controlling the temperature. Main switches for the motors 6 and the timer motor, the heaters, and a dryer fan are also provided with indicating lamps. An alternative form of the ball-release device utilizes a solenoid having a spring-biased core connected to a square-sectioned ballholder. The lowermost ball in the reservoir occupies a transverse hole in the holder and is carried side-ways to drop down a shoot on to the tape, the upper surface of the holder preventing further balls from falling until the solenoid has been de-energized, Fig. 6 (not shown).