Abstract: A connective joint comprises the following seven elements:(a) Four quarter spheres arranged in adjacent quadrant relationship to form a substantially spherical element or "ball". The quarter spheres are provided with grooved edges that form two substantially perpendicular grooves extending around the spherical element;(b) Two hinge elements, each having a ring shaped portion that is inserted in an individual one of the two grooves;(c) A device for applying a force between two diametrically opposing ones of the quarter spheres in the spherical element.

Abstract: This mechanical joint allows relative rotation of two articles (one may be a stationary fixture), on an arbitrary axis. The joint has as much angular-rotation range as a hinge, but as many degrees of freedom as a ball-and-socket or universal joint. It allows transmission, between the objects, of force or flux (e.g., of electricity, gas, or liquid), or both. It can be used as an applied-force or motion sensor, varying electrical contacts or conductivity in response to relative motion or force applied between the articles. In one form the invention is simply a mechanical joint formed of two closely interlocked toroids. The minor cross-section of each toroid is sized to just fit through the central aperture of the other; there is a connection point on each toroid for attachment of one article. By adjusting closeness of fit, a designer can impart to the device a wide range of desirable frictional properties.

Abstract: This fluid-current-transmitting mechanical joint allows relative rotation of two articles (one may be a stationary fixture), on an arbitrary axis. The joint has as much angular-rotation range as a hinge, but as many degrees of freedom as a ball-and-socket or universal joint. The invention has a dual outer structure consisting of two interlocked bodies, each generally arched and generally surrounding an aperture, with a connection point on each body for attachment of one of the articles; and a dual inner structure of two mutually fixed, interlocked rings or the like. The two bodies of the outer structure can be generally ring-shaped and if desired can take the form of two closely interlocked toroids, the minor cross-section of each toroid being sized to just fit through the central aperture of the other. These outer-structure bodies ride on the inner structure.