Binocular with focusing mechanism

Claim 1

A binocular comprising a pair of telescopes, a hinge pin hingedly connecting said telescopes together for swinging movement toward and away from each other for inter-pupillary adjustment, each telescope including a shell presenting a forward upper objective aperture and a rear lower eyepiece aperture, the planes of said apertures extending in parallelism, a lenscontaining eyepiece fixedly mounted in said eyepiece aperture, said objective aperture being provided with an internally threaded rim, a tubular lens-containing objective barrel having a rear threaded section threadedly received in said rim for focusing adjustment upon rotation of the barrel in either direction, an optical erecting system disposed within said shell and effective between said eyepiece and objective barrel, said barrel having a second threaded section forwardly of the rear threaded section, and an adjacent reduced cylindrical section terminating in an annular radial shoulder, a gear ring encompassing said cylindrical section and normally being freely rotatable and axially slidable thereon, a pinion rotatably mounted on said hinge pin and meshing with the gear rings of each telescope whereby rotation of either gear ring will induce rotation of the other gear ring, and a friction nut threadedly received on said second threaded section and effective when partially tightened against the adjacent gear ring to clamp said latter gear ring against the shoulder with varying degrees of friction whereby individual focusing of the lens-containing barrels may be attained by restraining rotation of either objective barrel while forcibly rotating the other objective barrel.