Patent GB-709949-A (GB)
Title: Improvements in or relating to frames for photographic contact or projection printing
Inventor: ASH BERNARD EDWIN
IPC: G03B27/02
Filed: 1951-08-28
Abstract: 709,949. Photographic contact and projection printing frames. HUNTER-PENROSE, Ltd. Aug. 11, 1952 [Aug. 28, 1951], No. 20306/51. Classes 98(1) and 98(2) A frame in which a rectangular, half-frame to support a rigid transparent sheet and a second half-frame to support a backing sheet are arranged to be clamped together in facing relation for angular movement about a central transverse axis common thereto, one half-frame, when released from clamped relationship with the other, being movable relative to the other to a position in which servicing of the half-frames or the placing or removal of an original and/or photographic lightsensitive sheet therebetween is facilitated, is characterized in that on each side of each half-frame and concentric with the central transverse axis is a semi-circular bearing member journaled in one half of a split bearing whereby the rectangular half-frames are released from clamped relation verse axis, the halves of the split bearings being so mounted as to allow separation thereof when the half-frames are deleased from clamped relation with each other. As shown in Figs. 1, 3, a frame for photographic contact-printing comprises rectangular half-frames 1, 2 supporting respectively a glass sheet 3 and a rubber backing sheet 4 supported by a back-plate 5. The half-frames are carried by supports 8 with wheeled bases. Each support 8 has an enlargement 9 at the top with a vertical groove for a sliding block 10. A bell-crank lever 13 pivoted to each support 8 has a handle 15, and is linked to the block 10 and to an arm 18, the arms 18 being connected by a rod 19 journaled in supports 8, so that levers 13 move together. Each block 10 has a key 20 at its upper end, which fits into a recess 21 in a boss 22 on the outer side of a semi-circular half-bearing 23. A compression spring 24 in recess 21 engages key 20. An annular projection 26 on the inner side of the half-bearing 23 fits a groove in a half-journal 28 fixed to the half-frame 2. A key 29, Figs. 4, 5, slidable in projection 26 and urged by a spring 32 to engage a recess 30 in the half-journal 28, has an extension 31 extending above the flat upper surface of halfbearing 23. The half-frame 1 similarly has a halfbearing 34 with a spring-pressed key 35 urged into a recess in a half-journal 33. When the half-frames are apart, keys 29, 35 lock the half-journals to the half-bearings, but when the half-frames, are together, the key extensions which are off-set are pressed flush with the flat surfaces of the half-bearings and clear the keys from their recesses. The half-bearings have studs and recesses 40 to ensure proper alignment so that, when together, they may rotate in the half-journals. Each half-bearing 34 is fixed to a T-shaped member 47 (Figs. 1, 3) having three wheels 48, 49, 50 engaging the upper and lower flanges of a channel-sectioned guide member 6 mounted-on each support 8. The T-shaped members 47 are connected to chains or the like 55 passing over sprockets on guide members 6, one pair of opposite sprockets being connected together, so that the members 47 move together. When the half-frame 2 is lowered by operating one of the handles 15,'the half-bearings and half-journals are separated, but the action of keys 29, 35 prevent rotation of the half-frames. The upper half-frame 1 can be moved, by means of the wheeled T-shaped members 47, across the face of half-frame 2. The ends of member 6 are curved down so that halfframe 1 may tilt at the end of its travel, and the flanges of member 6 diverge at the ends to provide stops for the members 47. After placing a negative and light-sensitive sheet in the frame, half-frame 1 is returned and half-frame 2 is raised. The air between sheet 4 and the glass or like sheet 3 may be pumped out in known manner. The half-frames can then be rotated, clamped together, the halfjournals 28, 33 turning in half-bearings 23, 34, into 'a vertical position for printing. The frames, when clamped together, may be rotated completely so that either of the half-frames may be brought to the top and displaced. In a modification, Fig. 6, the half-frames 1, 2 constitute a copy-holder for a photographic camera. The half-bearings 23, 34 are carried by blocks 59, 60, movable along a vertical post 64 and engaging a guide groove 63 therein. The blocks are connected by a cable or the like 65 passing over a pulley 66. The half-frames may be clamped together by known means and rotated into position for exposure. On return to the horizontal position the half-frames are unclamped and blocks 59, 60 are moved to separate them. Key 29 engages the recess 30 in the half-journal so that half-frame 2 cannot rotate. The corresponding recess 36a in half-journal 33 is, however, made of arcuate form to allow half-frame 1 to be tilted slightly.