Panchromatic folding zoom binoculars - have single knob zoom control and removable peg permitting compact folding together of parts

摘要

A panchromatic pair of binoculars has a guide shaft (3) with a knob (2) to adjust the magnification. An arm (4) at right angles to the shaft (3) is at one end. A parallel, stationary peg (6) is inserted in a vertical hole (5) in the arm. Hollow ares (7), at each end of the arm (4), house control cams (12) fitted to a part (8) of each tube. A control cylindrical cam (14) is so inserted in the tube that it free to rotate only. The cylinder has two inclined slits, and contains a part (16) with a central slit (15) which holds the objective lenses and can slide in and out. The holders (16) carry studs (18) which project to engage with the inclined slits. The whole instrument can be folded together for carriage and can be used as a zoom instrument when opened.