Hinged wrenches

Hinge mechanism

— a function found in wrenches with cap and end working parts (see the relevant paragraphs). In accordance with the name, in such keys, the cap or end working part is mounted on a hinge, which allows it to rotate relative to the key body. The simplest hinge is single-axis, it allows you to change the angle of rotation of the working part relative to the body. A more complex variety is a universal joint, which provides two axes crosswise: it is used with end working parts and allows you to rotate the key handle, holding it at an angle to the working part — the rotation will be normally transmitted to the working part. This way of working is useful when working in hard-to-reach places.