Adjustable friction plastic hinge having non-squeak properties

摘要

An adjustable friction hinge assembly for use on the lid or cover of a record player is made of plastic material. The hinge has anti- squeak properties to prevent squeaking when the lid or cover is raised. The hinge also has the capability of holding the lid, when raised, in the raised position without falling down. The knuckles of the hinge and the adjustment pin are made of a first plastic material having elastic properties, preferably acetal, while a washer of a different plastic material, preferably nylon, is placed between the facing end surfaces of the movable knuckles. The two different plastics are so selected that, when the two materials are in frictional engagement with each other, the coefficients of static and dynamic friction are similar. This avoids squeaking. The plastic adjustment pin passes through one end knuckle having an internal shoulder and screws into the other end knuckle. The head of the pivot pin abuts against the internal shoulder. When the screw is tightened to draw the facing knuckles toward each other and against each of the nylon washers, the plastic screw elongates slightly and sufficient reaction force is applied by the threads of the screw on the threads of the threaded knuckle to maintain the lid in the raised or other position in which it is placed.