The invention relates to an over-center hinge for furniture doors, which has a door-related part in the form of a cup-like element designed to be forced into a recess in the door, in whose peripheral wall a knuckle made separately and biased by a compression spring is mounted for pivoting within a given angle and slides, at least during a portion of the opening and closing movement, against a contact surface provided on the end of the other hinge part, and can be moved through a dead center position on one side of which it urges the door to the closed position and beyond which it exerts a pressure in the opening direction, the contact surface being situated adjacent the pivot axis of the knuckle when the knuckle is in the closed position.
Such hinges, whose over-center mechanism is formed by a resilient knuckle mounted in an opening in the circumferential wall of the cup-shaped element, are known. In such cases, in which the cup-shaped element and the knuckle are made of plastic, the knuckle was originally made integral with the cup-shaped element at its lower pivot point (DB Pat. No. 2,016,398). In further development of this known over-center hinge, the knuckle was then later made as a separate piece and held in the cup-shaped element by means of a pin passed through bores provided in the bottom end of the knuckle and in the cup-like element (DB Pat. No. 2,122,857). These known hinges have proven successful and are used in great numbers.
However, when the knuckle is being installed in the cup-like element of these known hinges, it can happen, though rarely, that the bore in the knuckle is not precisely aligned with the bores in the cup-like element when the pivot pin is being pressed into place. When the pin is being pressed in, it can then happen that the pin may deflect the knuckle sideways or even destroy its bottom pivot end. Such hinges in which the end has been destroyed or has not been penetrated by the pin have to be discarded, and therefore careful inspection of the assembled cup-like elements is necessary.