Abstract: A suspension device is provided for simulating the free-free boundary conditions of space for a low frequency structure. A support cable is connected at one end to the test structure and is vertically guided by a guiding ring. The other end of the cable is connected to a cam having an outer circumference which supports the cable. A drive axle passes through the cam center of rotation and is rotatably journalled in a suitable manner to a rigid structure. Two torsion springs are provided about the drive axle. One end of each spring is connected to a respective face of the cam and the other end is connected to the fixed support. The cam is shaped and the torsion springs selected such that Wr.sub.(t) =T.sub.s(t), wherein W is the weight of the test structure; r.sub.(t) is the instantaneous moment arm defined as the perpendicular distance from the rotational center of the cam to the cable at time t, and T.sub.s(t) is the total spring torque exerted by the two springs on the cam at time t.

Abstract: A rolling joint is provided for obtaining slewing maneuvers for various apparatuses including space structures, space vehicles, robotic manipulators and simulators. Two noncircular cylinders, namely a drive and a driven cylinder, are provided in driving contact with one another. This contact is maintained by two pairs of generally S-shaped bands, each pair forming a generally 8-shaped coupling tightly about the circumferential periphery of the noncircular drive and driven cylinders. A stationarily fixed arm extends between and is rotatably journalled with a drive axle and a spindle axle respectively extending through selected rotational points of the drive cylinder and of the driven cylinder. The noncircular cylinders are profiled to obtain the desired varying gear ratio.

Abstract: A low-friction, boat-type rocker arm assembly is provided. The boat-type rocker arm is designed to roll on a fulcrum of a supporting pedestal during operation, rather than slipping or sliding thereon. The rocker arm has a recessed intermediate area of a predetermined radius which is greater than the radius of the fulcrum of the pedestal. The rocker has a rectangular opening in the recessed portion with opposite, transverse edges tapering downwardly and inwardly which fit closely with the pedestal to limit travel of the rocker arm relative to the pedestal. The pedestal also has rounded surfaces at those portions positioned near the tapered edges of the rocker arm opening.

Abstract: In an engine valve train, each rocker arm and its associate fulcrum are provided with cooperating inner and outer cylindrical surface contours carrying the reaction forces of rocker arm, the ratio of the radius of the outer surface contour being approximately in the order of 3:1 to 1.7:1 and preferably 2:1, the rocker arm and fulcrum having a cooperating retainer recess and pin, intermediate the ends of the associate bearing surface, to maintain alignment of these elements in substantially rolling contact with each other during pivotable movement of the rocker arm. In the preferred embodiment the radii of curvature of these bearing surfaces are selected in the ratio of 2:1 so as to obtain rolling motion known as cardanic motion, the recess being defined by opposed inclined flat surfaces and, the working surfaces of the pin being of semi-circular profile in substantial two-point contact with the surface defined by the recess.