Abstract: A flexible arm particularly a robot arm comprising a plurality of elements engaging each other and being arranged in a series, said elements being interconnected via cables and if desired a power transferring actuating device. The purpose of the invention is to provide an arm having very good rigidity in the bending plane of the element and a high torsional resistance together with lower manufacturing costs as compared to conventional robot arms. This has been achieved by each element being designed with arched opposed single-or double-curved segments which with the curved surfaces of each segment engaging the surfaces of the adjacent segments, whereby the elements are arranged when actuated by the power generating and/or power transferring device to have a rolling motion relative to each other.

Abstract: A cleaning head is adapted to rest on and be moved over the material to be cleaned. The cleaning head has a central chamber, open at its bottom, and at least one relatively narrow chamber, open at its bottom, peripherally surrounding the central chamber. Ultrasonic transducer means are provided in the central chamber and means are provided for supplying a cleaning solution to the central chamber and for maintaining the level of the solution in the chamber such that at least a portion of the transducer means is immersed in the solution so that vibrations of the transducer means are imparted to the solution. Means are provided for adjusting, i.e. controlling, the pressure of the cleaning solution in the central chamber and the pressure in the at least one peripheral chamber to substantially eliminate the flow of air into the solution in the central chamber and to prevent escape of substantial amounts of solution from the cleaning head.

Abstract: A wrist watch comprising a case having holes therethrough and a cavity therein adapted to receive a watch movement; first and second segments each having a selected outer contour and a selected inner contour; a wrist band having holes therethrough in alignment with the holes in the case; the first and second segments have threaded cavities in alignment with the holes in the case and the holes in the wrist band; and screw means for clamping together the first and second segments, the wrist band and the case; and wherein the screw means includes threaded screws passing through the holes in the case, the holes in the wrist band and into the threaded cavities in the first and second segments.