Abstract: A power drive assembly having a housing, a drive mechanism removably installed in the housing, an annular biasing spring installed in the housing for biasing the mechanism, and a wear ring arrangement including an undercut annular groove in the mechanism opening coaxially toward an end of the biasing spring and a wear ring removably installed in the groove to engage the end of the biasing spring in the assembled arrangement of the power drive assembly. The wear ring has a cross section complementary to the undercut groove cross section whereby the mechanism may be installed in the housing with the groove opening downwardly and the wear ring maintained in the groove for facilitated assembly of the power drive.

Abstract: A compression spring capable of having a very high rate comprises co-axial annular plates alternating in an axial direction with diametrical strips adjacent ones of which are perpendicular to one another. The spring may comprise a stack of washers with diametrically opposed pads or radial ribs on their faces, said washers having non-circular bores enabling them to be located non-rotatably on a correspondingly non-circular central support. Alternatively, the spring may comprise a single tubular element with pairs of diametrically opposed tangential slots perpendicular to its axis which extend from its periphery into its bore.

Abstract: A primary antenna reflective structure is supported for pivotal movement in the elevation direction between the zenith and horizontal points. Drive motors via a bull gear rotates the antenna through its permissible travel. Inertia counterbalance is utilized to control the motion of the antenna. That counterbalance comprises a pinion driven by the bull gear. Left and right guides are integral with the pinion and followers are contained within housings and are adapted to be driven by the guides. The followers move in opposite directions and either compress or relax springs which are housed concentric with the guides. The guides comprise either a ball screw or roller screw, and the followers either a ball nut or roller nut.

Abstract: Pressing apparatus wherein a cell containing a workpiece is subjected to pressure in a press in which at least one resilient layer of disc-spring units is used as a pressure distributing medium comprises a press, two press plates and a pressure distributor disposed between the pair of plates and one of the press platens. The pressure distributor consists of a plurality of disc-spring units disposed adjacent to one another over the surface of a supporting plate. Each disc-spring unit comprises a pair of disc-springs disposed one on either side of the supporting plate with the apexes of the springs towards each other, the springs of each pair being fastened together by means of rivets passing through an orifice in the plate.

Abstract: A regenerative heat-exchanger of a gas turbine whose ceramic heat-exchanger disk is coaxially surrounded by a metallic toothed rim under formation of an annular space in which are arranged springs; the springs are constituted by spring packets of cup springs which are guided on both sides in concave recesses in two webs arranged in the circumferential direction on entrainment plates which surround the lateral surfaces of the toothed rim and are non-rotatably connected therewith.