Piston joint

An apparatus comprising:

• at least one piston;
• a transition arm;
• a joint coupling the piston to transition arm, the joint including:
• an outer member configured for movement relative to the piston along a first axis, the outer member defining first and second parallel flat sides, the outer member defining an opening for receiving a portion of the transition arm, and
• an inner member mounted within the outer member for rotation relative to the outer member about a second axis and for movement relative to the outer member along the second axis, the outer member being restrained from movement along the second axis, the inner member defining an opening for receiving the drive arm;
• and
• a rotatable drum defining a cylinder, the cylinder housing the piston.

An engine comprising:

• at least one piston;
• a transition arm;
• a joint coupling the piston to transition arm, the joint including:
• an outer member configured for movement relative to the piston along a first axis, the outer member defining first and second parallel flat sides, the outer member defining an opening for receiving a portion of the transition arm, and
• an inner member mounted within the outer member for rotation relative to the outer member about a second axis and for movement relative to the outer member along the second axis, the outer member being restrained from movement along the second axis, the inner member defining an opening for receiving the drive arm;
• a universal joint connecting the transition arm to a support;
• a cylinder housing pistons and having a spark plug and inlet and exhaust valves;
• and
• a distributor for controlling the timing of the spark plugs and cam shafts for the operation of the inlet and exhaust valves.