Abstract: A lawn mower having a transverse cutting bar and a rotary cutter assembly fitted with a plurality of curved cutting edges that maintain substantially constant contact with the transverse cutting bar and reciprocate along the cutting bar to provide a shearing action for lawn mowing purposes. In the presently preferred embodiment of the lawn mower, the cutting edges are the edges of a plurality of generally elliptical blades mounted on a central shaft, the blades each having a longitudinal midsecton disposed at an angle of about 30.degree. with the axis of the shaft so as to wobble along the transverse cutting bar as the cutter assembly rotates. The blades reciprocate along a portion of the length of the transverse cutting bar with their ranges of reciprocation overlapping to result in a smooth cutting swath. Each of the blades has cutting edges of generally S-shaped side profile, and is formed with symmetrical outturned flanges on each longitudinal half of such character as to insure substantially 90.degree.

Abstract: A headpiece with two built-in fan units for cooling the face and back of the neck of a surgeon while he or she is performing surgery. Each of the fan units has a fan blade mounted perpendicularly within a cylindrical housing in close tolerance with the inner wall of the housing and includes an electric motor having a drive shaft to which the fan blade is attached. The motor and fan blade assembly is supported by vanes interconnecting it with the cylindrical housing which extend radially outwardly from the axis of the assembly. The headpiece has a frame that fits a wearer's head like a hat and supports the two fan units, one in front and the other in back of the frame. The frame also supports a power source for the two fan motors and other components of circuitry which permit adjustment of the speed of each motor for optimum cooling effect. The fan units are pivotally mounted and manually adjustable to different angular positions for control of the direction of airflow in front and back of the wearer's head.

Abstract: An external combustion engine wherein a plurality of radially disposed piston cylinders are arranged around the axis of an output drive shaft. Pistons are reciprocal in the cylinders and actuate rollers carried by radially extending slide bearings, the rollers engaging in an eccentric cam groove formed in a flywheel fixed to the drive shaft. The cylinders have closed inner and outer ends and are provided with valve means for applying pressurized gas to opposite ends of the pistons at different times in a manner to provide power to a majority of the pistons at all times during rotation of the drive shaft. The engine can alternatively operate as a pump by applying motive power to the shaft.