GB650141A - Improvements in mounts for photographic objectives - Google Patents

Abstract

650,141. Photographic objective mounts. KERN & CO., AKT.-GES. Aug. 23, 1948, No. 22155. Convention date, March 12. [Classes 97 (i) and 98 (i)] The mount comprises a sleeve 3 axially movable without rotation in a carrier 1 fixed to the camera, by engagement with a screwed focusing ring 14, 15 and having screw-threaded within it a rotatable diaphragm ring 7 carrying the objective L1, L2, L3, L4, and an iris diaphragm 8, the focusing ring carrying a distance scale on which one boundary of the depth of field is indicated by a mark 23 on the sleeve and the other by a mark 25 on the diaphragm ring, the arrangement being such that when one boundary has been set against the mark 23 by rotation of the focusing ring to move the sleeve, the other boundary can be set against the mark 25 by rotation of the diaphragm ring, which causes axial movement of the lens and diaphragm within the sleeve and simultaneously adjusts the diaphragm aperture without movement of the mark 23. The focusing ring comprises a ring 14 screwed to the carrier and having attached thereto a ring 15 having a conical portion 21 bearing the distance scale, an annular head 13 on the sleeve 3 engaging between the rings 14, 15 to be moved thereby, rotation of the sleeve being prevented by a pin 5 engaging a slot 4 in the sleeve, which slot also holds a stud 11 fixed to the diaphragm operating ring so that the latter cannot rotate as the diaphragm is turned with the diaphragm ring 7. The mark 23 is on a ring 22 fixed to the outer end of the sleeve and also carrying a mark 27 against which a diaphragm scale fixed to the ring 7 is read.