GB965362A - Improvements in, or relating to, photographic enlargers - Google Patents

Abstract

965, 362. Photographic enlargers. T. F. BLUMFIELD. May 23, 1963 [May 23, 1962], No. 19778/62. Heading G2A. In an enlarger having a masking frame movable on a supporting platform, the frame comprising a base and a hinged upper part, the said frame is anchored on the platform by at least one arm, of which one end is connected to the frame by a swivel joint and the other end is releasably secured to a fixed part of the enlarger. In the form shown, the light source and objective lens (not shown) are carried on a vertical sleeve 3 bolted to a shelf-like extension 2 of a platform 1. Resting on the platform is the masking frame 4, comprising a base 5 and an upper part 6 hinged to the base at 7. On adjacent arms of part 6 are two adjustable slides 10 carrying scales 9. In using the enlarger, the frame is set at a predetermined position on the platform, the top hinged upwards, a sheet of sensitized paper placed in position, and then clamped there by bringing the top down again. The frame has two spherical-headed studs fixed to its base, and each stud fits into a similarly shaped socket at the end of a plastic link member 11. The other end of each link member is tapped, and into each screws the threaded end of a cranked rod 12, locked by a wing nut 13. Each rod 12 passes through a groove in a plate 17 which rests on a disc 15 fixed on a pillar 14 projecting from the shelf 2. Plate 17 can be clamped firmly against disc 15 by a threaded bolt 16, thus gripping rod 12 securely, and hence holding the frame 4 firmly against movement. The frame can be adjusted to any position on the platform by slackening the bolts 16 so that the rods 12 slide freely, after which they are tightened up again to hold the frame securely in the selected position. The hinge can thus be swung up and down without disturbing the position of the frame.