Patent GB-191020798-A (GB)
Title: Improvements in Photographic Printing Machines.
Inventor: OLSON GUSTAVE REUBEN
IPC: G03B27/16
Filed: 1910-09-06
Granted: 1911-07-20
Abstract: 20,798. Olson, G. R. Sept. 6. Printing-apparatus, rapid bromide and like. -Relates to a printing-machine for printing a number of photographs from the same negative with a uniform exposure, and consists in improved means for supporting the sensitized sheet; means for adjusting an electric lamp; means for automatically opening and closing the light-circuit; and means for timing the exposure. Fig. 1 is a front view, and Fig. 4 a sectional side view, of the machine, Fig. 8 shows one form of switch, Fig. 9 shows the negativeholder, Fig. 10 shows the platen-back support and sensitized-sheet holder, and Fig. 13 shows the sliding timing-device. A vertical support 1 has an opening 2 opposite a vertically adjustable box 51 containing electric lamps 50, which slide on pins 58 in slots in the top of the box 51, along which slots are scale graduations. The negative-holder 3, Fig. 9, carries the negative N on a strip 5, or on the notches 8 of sliding guides 6 if the negative is small. A frame 9 pivoted at 10 carries two sleeves 11 which support negative-retaining strips 13. The holder 3 is adjusted vertically by a pivoted rod 17 moving over a graduated scale and connecting-links 18, 19. The sensitized paper E is supported on a rubber-covered pressure back 22, Fig. 10, carried by a platen 21, the platen having forked legs 23 pivoted at 24 to the support 1. A bellcrank arm 27 pivoted at 28 to a frame 25 secured to the support 1, operates the platen 21 through a connecting-link 29. The pressure back 22 is resiliently connected with a crossbar 26 on the platen 21 by springs 32. A pivot 33 and a clamping-screw 34, connected with the platen and working in a curved slot in the cross-bar 26, permit an angular adjustment of the pressure back. The sensitized sheet E is supported on a retractable plate 36 guided by pins 35. This plate 36 is withdrawn by a hooked lever 37 operated by the link 29 on the platen 21 when the platen is withdrawn, thus allowing the print to drop out of the machine. A spring 40 returns the plate 36 to its initial position. A side stop arm 41 for the sensitized sheet is fixed on an adjustable sleeve 42 on a rock-shaft 43, this stop arm being forced by a spring 47 on the rock-shaft to swing against the pressure back when the platen 21 is retracted, to position the paper E properly. A projecting arm 48 on the shaft 43 engages a trip 49, and removes the stop arm 41 when the platen is returned. One form of switch, Fig. 8, is mounted on a support 61 hinged at 62 to the main support 1 so as to swing towards the timing-mechanism, which automatically operates the switch. The two leads 60 are attached to one fixed pole 67 and to a pivoted arm 64 having stop arms 74 which are operated by a trigger 69 pivoted at 70 and having side arms 71, 72, which are engaged by trips on the timing-device. In another form of switch, one end of the lever dips into a mercury cup, and, in a third form of switch, into two mercury cups. The timing-device consists of a timing-bar 76, Fig. 13, adapted to slide by gravity upon vertical bars 79, its downward motion being regulated by a fan 89 rotated through gear-wheels 91 bv a rack 93 attached to the top of the timing-bar 76. Two tripping-devices for switching the light on and off are fixed to the timing-bar, one 77 fixed at the bottom, and an adjustable one 78 adapted to slide in a groove 84 in the timing-bar. A resetting-device for the timing-bar 76 is situated behind the switch board 61 and slides on the rods 79. It is operated by a connecting-rope from the platen 21, a ratchet device preventing rotation of the fan 89. When the device is to be started, the pressure back 22 with a sensitized sheet E is brought towards the negative N by the handle 27. Simultaneously, a trigger is removed by the rod 112 from underneath the timing-device, allowing this to fall, whereupon the bottom trigger on the timing-device switches on the light. As the timing-bar continues to fall, the upper trip 78 switches off the light, whereupon the platen may be retracted, and the sensitized print E removed, whereby the timing-bar is automatically drawn up and re-set for another print.