The invention refers to a universal ball pivot-link chain arrangement comprising a plurality of chain link elements, each of said chain link elements possessing at one end a ball pivot body and at the other end a ball socket adapted to receive the ball pivot body of the directly neighboring chain link element, each of said chain link elements being subdivided in an axial plane into two halves and possessing a ring connection located in the end region of the ball socket.
A universal link chain of the aforementioned kind is disclosed in U.K. Pat. No. 980'302. It is used there as a tension chain for load hoisting hooks guided on rails by means of rollers. The load hoisting hooks are connected with the chain link elements by way of two bearing sleeve halves fastened to each other by screws, each chain link element shaft adapted to connect the ball pivot body with the ball socket being held in place between said two bearing sleeve halves. In spite of this additional connection a wedge is inserted between the two chain link element halves and made to engage a recess in each of said halves to safely prevent any axial displacement therebetween. This same object is pursued by the provision of a shoulder on the chain link element shaft, which is thus embraced by the bearing sleeves laterally too, so as to make them hold the halves of the chain link elements fixed not only in the radial but also in the axial direction. All of these measures indicates that if the chain link elements are subdivided into two halves which must be held together but also secured against a relative motion in the contact plane thereof, it is extremely difficult to maintain the geometrically correct form of the ball pivot body and the counter surface of the ball socket, particularly under varying operating conditions. In this connection it is noteworthy, that this known link chain is meant to transmit pulling forces only, which results in a continuous centering process taking place between the ball pivot bodies and the ball sockets enclosing the same because the chain is continuously being stretched. In a thrust or pushing type operation, on the other hand, in which the chain would have to be guided within a channel or some similar guide means, the neighboring chain link elements show a tendency to buckle, resulting in forces acting individually upon the halves of the chain link elements and thereby creating the danger of a relative displacement between said two halves.
USPTO Backgrounds
USPTO Backgrounds