Spectacle frame spring-loaded hinge has spring tension adjuster in form of screw in closed end of sleeve containing spring and rod

摘要

The hinge consists of one hinge member on the frame lens surround and another (4) sliding in a sleeve (9) on the forward end of the frame side-piece and equipped with a rod (10) with a spring (14) and end cap (13). The closed end of the sleeve has a threaded bore to receive a screw (16), the shank (17) of which engages with the bore and allows the tension of the spring to be adjusted by varying the pressure of the screw tip on the rod cap.