Abstract: A driving interconnection between two eccentrically rotating members for rotation at the same angular velocity about their respective axes without angular phase shift. The invention is adaptable to join an outer rotatable member to an inner one and is particularly useful for coupling the interior rotor and the external cam ring in certain types of positive fluid displacing devices. In one embodiment, the coupler comprises a central body with four outwardly extending arms. Two of the arms engage tightly fitting slots in the inner rotating member. The other two arms pass through clearance slots in the inner member and engage tightly fitting slots in the outer rotating member.

Abstract: A coupler for joining two eccentrically rotating members for simultaneous rotation about their respective axes at the same angular velocity without angular phase shift. The invention is particularly useful for coupling the rotor and cam ring in certain types of positive fluid displacing devices. The coupling includes a double crank member with a central portion extending along a first axis and two end portions extending from each end of the central portion along a second axis parallel to the first. The central portion is received in a bore in the inner member and the end portions are received in opposing mutually parallel slots in the outer member.

Abstract: A method of, and bolt for, supporting a structure such as a mine or tunnel roof or side wall or the like.