Abstract: A bowling ball thrower includes a frame positionable adjacent to a bowling lane, a throwing arm pivotably attached to the frame, the throwing arm having a rest position and a pivoted position and including a ball-gripping mechanism for gripping a bowling ball, and a cocking arm pivotably attached to the frame, the cocking arm being selectively couplable to the throwing arm such that the cocking arm is pivotable with the throwing arm. A method for throwing a bowling ball includes holding the bowling ball with a ball thrower having a throwing arm and a cocking arm, and coupling the throwing arm to the cocking arm. The method also includes pivoting the throwing arm to a pivoted position to achieve a velocity, uncoupling the throwing arm from the cocking arm, and releasing the bowling ball such that the bowling ball moves at the velocity.

Abstract: A rotary-driven valve is coupled to a rotary actuator. The coupling includes a shaft having longitudinally extending drive pins offset from the shaft axis. The drive pins contact drive surfaces of drive plates which have a valve stem opening which mates with the valve stem. The drive plates can slide relative to the valve stem with one degree of freedom, and the drive pins can slide relative to the drive plates with a second degree of freedom. Sliding movement of the first drive plate and/or the second drive plate allow the shaft axis to be angled and/or laterally displaced relative to the valve stem axis. The drive plates provide a dynamic adjustment freedom so bending moments and radial forces are not imposed on the valve stem. The drive plates may also provide thermal insulation between the valve stem and the actuator.