Abstract: A barrel-type reciprocating machine having a block with a shaft journaled through its center with the ends of the shaft offset at an oblique angle. A pair of wobble spiders are attached to the oblique crank end of the shaft and are in turn attached to an output shaft. A plurality of cylinders are angularly spaced around the shaft parallel to the axis of rotation of the shaft. Each cylinder has a pair of opposing pistons and a plurality of intake and exhaust ports which are open and closed by the opposing pistons. Semi-circular concentric intake and exhaust manifolds surround the cylinders and communicate with the ports leading to the cylinders. The intake manifold has a plurality of coolant tubes passing through the wall of the intake manifold and into the cavity for cooling the intake air passing through the manifold into the cylinder. The coolant tubes traverse a circuitous path through the manifold and pass back out through the wall of the intake manifold to hose fittings.

Abstract: The invention provides an equalizer or control unit to be used in conjunction with the present day type of parking meter. The control unit of the invention comprises an ultrasonic transmitter and receiver system which senses the presence of a parked vehicle, and which controls the parking meter in a manner such that the time remaining in the meter is returned to zero when the vehicle is driven away. The system to be described also controls the meter in a manner so as to prevent anyone from inserting coins into the meter after an initial parking interval has expired thereby to prevent the monopolization of the parking space by one vehicle over extended periods of time.