Abstract: A rotary transmission device for a plurality of cables between to coaxial, utually restrictedly rotatable structures, especially for space satellites. One of said structures is formed with a cylindrical housing (9) while the other structure is formed with a hollow hub (8) coaxially extending through said housing (9). At least one support band (3) extends in the form of a spiral between the wall (10) of the housing (9) and the hollow hub (8) and is slidably supported at two plates (1, 2) forming the bottom and the cover of said housing (9). A plurality of individual electrical cables (6) are laid along the support band (3) in a slightly wavelike course, the cables (6) being fixed to the support band (3) at every second wave apex are retained at the other wave apices with radical and axial clearances with respect to the spiral.

Abstract: An electromagnetic diaphragm disk actuator is both easily driven and posiely held in its desired controllable relationship. The actuator includes a stator having a driving rim with a driving tooth system, a holding rim spaced axially away from the stator with a holding tooth system, a plurality of pairs of electromagnets in the stator and a rotor connected to a drive shaft having a magnetically attractable diaphragm with cooperating driving and holding tooth systems positioned around the circumferential edge and on opposite sides thereof lying between the stator and the holding rim. The diaphragm is positioned between the driving rim and holding rim such that the engagement points of the driving and holding tooth systems deform the diaphragm to the point that it develops an apex generally defined by the axis between the points of engagement of the holding tooth system and such axis is displaced 90.degree. relative to the axis formed by the engagement points of the driving tooth systems.