Cruciform engine

A cruciform reciprocating engine including a crank case, an elongate crank shaft with opposite ends rotatably supported by the case on a central turning axis and an elongate central crank pin within the case on a second axis parallel with and spaced radially outward from the turning axis, two pair of elongate cylinders with radially disposed inner and outer ends on radial axes extending radially of and intersecting the turning axis, the inner ends of the cylinders are secured to the case, the radial longitudinal axis of each pair of cylinders is at right angle to the radial longitudinal axis of the other pair of cylinders, said radial longitudinal axes are spaced axially of the crank pin, an elongate piston unit is engaged with and extends between the cylinders of each pair of cylinders, each piston unit includes an elongate yoke on a radial plane parallel with the radial longitudinal axis and normal to the turning axis, said yoke has a bearing opening intermediate its ends on an axis parallel with and spaced radially from the turning axis and from the crank pin, said yoke has opposite ends disposed toward related cylinders, an elongate cylindrical piston with radially disposed inner and outer ends is secured to each end of the yoke and is shiftably engaged in the cylinder related thereto, an elongate twin eccentric disc driver is drivingly engaged with and between the crank pin and the yokes, the driver includes a pair of axially spaced cylindrical discs, each disc is rotatably engaged in the bearing opening in a related yoke, the central axis of the discs are on spaced parallel third axes spaced radially from opposite sides of the second axis of the crank pin a distance less than one quarter their radial extent, said driver has a crank pin opening intermediate and parallel with the third axes in which the crank pin is rotatably engaged, a head is engaged on and closes the radial outer end of each cylinder;

• scavenging means controls the flow of fluid into and out of the cylinders;
• each piston has an outer portion with piston ring grooves;
• piston rings are engaged in the grooves for substantial free limited radial shifting therein and project from the grooves and engage the inside surface of the cylinder related thereto, each piston has an inner portion with a longitudinally elongate, radially outwardly opening bearing sleeve channel with a radially outwardly disposed cylindrical bottom and axially-spaced opposing ends;
• and, an elongate, annular, bearing sleeve is engaged in and projects radially outward from the channel, the bearing sleeve has radially inwardly and outwardly disposed longitudinally extending inside and outside bearing surfaces in load-transmitting bearing engagement with the bottom of the channel and the inside surface of the cylinder and has axially disposed ends opposing related ends of the channel.