Lens cap for optical instruments with pivotally mounted lens cover

Claim 1

A lens cap for mounting on the lens mount of a camera comprising: a tubular cylindrical member for attaching at one end on the front end of the lens mount of the camera, said one end being threaded for engaging mating threads on the lens mount, said cylindrical member defining a ledge at its other end around its periphery forming a lens cover seating surface, a lens cover pivotally mounted on the outside periphery of said cylindrical member and comprising a substantially flat disc for covering in one position the camera lens, the periphery of said disc engaging said seating surface in lens cap closed position, said disc having a protrusion extending from its peripheral edge for interfitting with a receiving member on the periphery of said cylindrical member to provide the pivotal mounting of said lens cover, and spring means extending between said lens cover and said cylindrical member for biasing said disc to one of its lens open and lens closed positions, said spring means comprising an arcuate shaped spring, one end being attached to the periphery of said member and its other end being connected to said disc, said lens cover being provided with a lever arm extending outwardly from its periphery, whereby said lens cover may be pivotally moved by the user applying finger pressure on said lever arm against the biasing action of said spring to pivotally move said lens cap, said lever arm defining a slot, and one end of said spring means extending through said slot of said lever arm to said cylindrical member, whereby said spring means is retained and the amount of its deflection is controlled by the sides of said slot when said lens cover is moved to open and closed positions.