Abstract: A piston compressor. First and second manifold plates are joined together with their inner surfaces in fluid-tight abutment. First and second cylinder housings are affixed to the outer surfaces of the first and second manifold plates, respectively, in fluid tight fashion and oriented at 90.degree. with respect to each other. Each cylinder housing contains first and second opposed, fixed piston rod/piston head assemblies, each extending axially from an end of its respective cylinder housing. Each cylinder housing contains an elongated sleeve having an axial bore at each end receiving one of the piston heads in sealing engagement and defining therewith a compression chamber. A crank comprising a crank element and oppositely directed crank pins having its crank element located in a central hole in the manifold plates and its crank pins each mounted in bearings in a central transverse hole in one of the sleeves.

Abstract: An internal combustion engine includes a housing having a first cylinder chamber and a second cylinder chamber, wherein the cylinder chambers are perpendicular to each other. Each cylinder chamber includes a reciprocating piston assembly having a compression piston head and a combustion piston head connected by a hollow tube. A crankshaft is rotatably connected to each piston assembly and to a power transfer assembly. The power transfer assembly transfers rotary motion of the crankshaft to an output shaft.

Abstract: One embodiment of the present invention concerns a plate having a coil spring indicator positioned thereon and a retaining means for retaining the indicator from its normal vertical position to a horizontal position. A pair of such plates are adapted to be mounted upon the side of a mailbox. In another embodiment of the present invention, a conventional rural mailbox is initially manufactured with a pair of spring loaded indicators positioned on the side of the mailbox and having a pair of retainer means being positioned between the spring loaded indicator and the door of the mailbox. By using a pair of spring loaded indicators, the present device indicates when mail has been deposited by the resident in the mailbox for pickup by the mailman, and when mail has been deposited by the mailman for pickup by the resident.

Abstract: A muffler capable of suppressing the shockwave generated by an internal combustion engine forming a housing having an inlet and an outlet and a center rectifier section extending between the inlet and the outlet, the center rectifier section having a transverse cross-sectional area substantially the same as or greater than the transverse cross-sectional area of either the inlet or the outlet, and having a small dimension and a large dimension, the large dimension being several magnitudes of order greater than the small dimension.