GB765272A - Improvements in or relating to binocular optical devices - Google Patents

Abstract

765,272. Binoculars. LEITZ GES., E'. Feb. 24, 1955 [May 17, 1954], No. 5557/55. Class 97(1) In a binocular optical instrument one eyepiece is connected to the focusing knob through a releasable clutch so that the other may be adjusted independently of it to compensate for the difference in focusing ability between the eyes of an observer. As shown, the drive between focusing knob 9 and lens 21 is interrupted on pressing the knob axially against the action of spring 8 to release the frictional coupling, through friction disc 22, between knob 9 and head 18 of shaft 16. Sleeve 5 is keyed for rotation with the spindle, of knob 9 but is prevented, by engagement with sleeve 2, from moving axially therewith. Screw 12 is prevented from rotating in sleeve 2 by the engagement of projection 12a in slot 2b so that on rotation of knob 9, the axial movement of. screw 12 is transmitted by arm 26 and sleeve 13 to lens 15. Shaft 16 is prevented from moving.axially by disc 17 engaging sleeve 2 and by cap 3, and its rotational movement displaces nut 19 and lens 21 therewith rectilinearly. Resilient washer 23 serves as a seal, and additional seals are provided between the cap 3 and the adjacent parts. The knob 9 may be provided with a transparent cover 24 and the head 18 of shaft 16 may have a scale graduated in dioptres. The recess in screw 12 for arm 26 is sectorshaped to enable tubes 1 and 1a to which the outer components of the objectives and the eyepieces may be sealed to pivot about sleeve 2. Components of the optical systems other than lenses 15 and 21, such as prisms, may be axially movable to effect the focusing. Specification 285,094 [Class 97(i)] is referred to.