Abstract: An improved helmet is provided including means to telescopically acquire an image of a field of view, which comprises, a telescopic optical system including an objective lens mounted to said helmet above the line of sight of the wearer, a light-conducting fiber optics bundle mounted to said helmet for receiving the image from the objective lens, and collimating lens for receiving the image from the fiber optics bundle and projecting the image onto a helmet-mounted visor in the line of sight of the wearer. A shutter, remotely controllable by the wearer, may be disposed intermediate the objective lens and display to selectively block transmission of the image.

Abstract: A method and apparatus for encoding binary data in a data stream so as to increase the number of data bits represented by one transition, such as a transition recorded on a magnetic medium, and thereby increase the storage density. The data stream is converted into words each having m bits. Two of the data words are stored so as to be simultaneously accessible to a converting system that converts the data words into code words wherein each code word has n bits. In the invention, m/n=2/3. In order to increase the space between adjacent transitions, the conversion is carried out according to a scheme wherein all code words have at least one binary ONE and lack successive binary ONEs except certain cases in which a code word is converted to all ZEROs to avoid ONEs in the nth bit of a given code word and the first bit of the code word following the given code word. Also described is a decoding method and apparatus for recovering the encoded data and decoding it to the original binary data.

Abstract: A cord take-up reel for use on an electric lawn mower. The reel is telescopically constructed to permit its axial dimension to be adjusted for mounting between a pair of opposing mower handles. A pair of shafts extending outwardly from opposing sides of the reel are detachably and rotatably mounted in brackets held on the opposing mower handles. A crank pivotally attached to one of the reel shafts is positionable between a winding position and a stowed position, the motion of the crank in its stowed position being limited by a cradling member attached to the adjacent bracket.

Abstract: A valve having stacked disks with alternate circular grooves in the faces thereof to provide a high pressure drop surface in fluid flow transverse to said grooves and ridges. The disks are circular in shape with a circular center opening to provide a central fluid opening when the disks are stacked with the center openings in register. Fluid enters the center opening and flows radially between the adjacent faces of a pair of disks to flow transversely across the continuous circular grooves and ridges.