Abstract: The present invention is directed to a rotary joint that includes a power slip ring and an electric signal slip ring, both for passing electricity between a stator and a rotor The system includes a plurality of slip rings (21,31) and a plurality of circumferentially extending fluid flow annular passages (12, 13, 14) formed in axially aligned relaation between the stator and the rotor. Water passages are constituted by some of the annual passages (12,13) and one of the annular passages (14), typically the lowest one, is used an air passage for air under pressure or an air-filled drain so that water leakage can be absorbed into the air passage or drain and does not penetrate into the region of the slip rings. The slip ring (21) with collector rings (22) is used for power and slip rings (31) are used for signals. Water passages are constituted by the annular passages, other than one of the annular passages located towards the power slip ring and the electric signal slip ring.

Abstract: In a rotary joint A including an electric signal slip ring 31 for passing different electric signals between a stator 1 and a rotor 6, for the purpose of stable transmission of electric signals in the electric signal slip ring 31, stationary side electrode stacks 38a and 38b are provided individually by stacking each pair of axially adjacent two 36b to 36e of six ring-plate-shaped stationary side electrodes 36a to 36f arranged concentrically with the axis of the stator 1 and aligned axially with each other together with one of stationary side insulating seats 37a and 37b interposed between the pair of axially faced stationary side electrodes, rotating side electrode stacks 42a to 42c are provided individually by stacking each pair of axially adjacent two 40a to 40f of six ring-plate-shaped rotating side electrodes 40a to 40f arranged concentrically with the axis of the rotor 6 and aligned axially with each other together with one of rotating side insulating seats 41a and 41c interposed between the pair of axi

Abstract: A robot arm coupling apparatus. This apparatus has an inner assembly attached to a robot arm, an outer assembly to which a tool or the like is attached and a locking means to lock both assemblies to each other. Said locking means comprises a piston member supported by the inner assembly slidably between the locking position and the unlocking position, a plurality of ball members surrounding said piston member and supported by the inner assembly, and a ball retainer which is provided at the outer assembly, which is contactable at its tapered surface with the ball member and holds both assemblies together, when the piston member moves to the locking position, in cooperation with the ball member. The working surface of the piston member including first and second tapered surfaces and at least an axially extending cylindrical surface.