Abstract: A traction unit capable of traversing and turning on surfaces that include compound curves like the surface of a sphere or are inverted like a ceiling. The traction unit includes a plurality of trucks operable to propel the unit across a surface and a plurality of adherence members operable to releasably secure the unit to the surface. In operation, the adherence members cyclically attach to and release from the surface as the trucks propel the unit across the surface. Within each cycle, after the unit has traveled a predetermined distance relative to an attached member, the member releases the surface and reattaches to the surface at a different point.

Abstract: A traction unit capable of traversing and turning on surfaces that include compound curves like the surface of a sphere or are inverted like a ceiling. The traction unit includes a plurality of trucks operable to propel the unit across a surface and a plurality of adherence members operable to releasably secure the unit to the surface. In operation, the adherence members cyclically attach to and release from the surface as the trucks propel the unit across the surface. Within each cycle, after the unit has traveled a predetermined distance relative to an attached member, the member releases the surface and reattaches to the surface at a different point.

Abstract: A traction unit capable of traversing and turning on surfaces that include compound curves like the surface of a sphere or are inverted like a ceiling. The traction unit includes a plurality of trucks operable to propel the unit across a surface and a plurality of adherence members operable to releasably secure the unit to the surface. In operation, the adherence members cyclically attach to and release from the surface as the trucks propel the unit across the surface. Within each cycle, after the unit has traveled a predetermined distance relative to an attached member, the member releases the surface and reattaches to the surface at a different point.

Abstract: A traction unit capable of traversing and turning on surfaces that include compound curves like the surface of a sphere or are inverted like a ceiling. The traction unit includes a plurality of trucks operable to propel the unit across a surface and a plurality of adherence members operable to releasably secure the unit to the surface. In operation, the adherence members cyclically attach to and release from the surface as the trucks propel the unit across the surface. Within each cycle, after the unit has traveled a predetermined distance relative to an attached member, the member releases the surface and reattaches to the surface at a different point.

Abstract: A propulsion system for accelerating and directionally controlling a fluid having a continuous dynamic surface for circulating through a fluid from an entrainment region where fluid is introduced to the dynamic surface to a thrust region where fluid is discharged from the dynamic surface. The dynamic surface accelerates the fluid proximate to the surface so as to produce a layer of accelerated fluid from the entrainment region through the thrust region. A motor is operatively connected to the dynamic surface for driving the dynamic surface. A separator plate is positioned next to the dynamic surface. The separator plate has a leading edge for stripping the layer of accelerated fluid from the dynamic surface, and a substantially flat thrust face adjacent to the leading edge for directing the accelerated fluid in a desired direction.

Abstract: A collapsible boat whose lateral hull walls are retractable to reduce the width of the boat is provided. Port side and starboard side lateral hull walls are pivotally connected along their lower edges to the central hull section of the boat. When extended, the lateral hull walls form a sloping hull wall extending upward and outward from the bottom of the central hull section. When retracted, the lateral hull walls pivot inward to reduce the width of the boat. Port side and starboard side braces are pivotally connected to the upper lateral edges of the central hull section for movement between an engaged position and a retracted position. In the engaged position, the braces connect to the lateral hull walls to keep them in their extended position. In the retracted position, the braces are pivoted inward to allow the hull walls to retract.

Abstract: A parachute assembly including a pilot chute, pilot chute suspension lines, a main chute, and a main chute suspension assembly. The main canopy has an inverted apex and has an inner section of panels and outer section of panels joined by a reinforced crown seam. The seams are secured with two parallel longitudinal stitchings with a relatively elastic thread and a zig-zag stitch with a relatively inelastic, stronger, heat-resistant thread. There are only half as many continuous panels in the inner section as compared to the outer section. Bands are connected to the lower lateral margin of the main canopy. The pilot chute is connected to the main chute by spaced, individual suspension lines which connect directly between the periphery of the pilot chute and the crown of the main canopy. The size of the pilot chute and the length of the suspension lines are coordinated so that the pilot chute is held near the top of the main canopy when the main canopy is fully deployed.

Abstract: A release mechanism is provided for releasably joining two objects such as straps, cables, ropes, or the like as well as two rigid members such as pipes, tubing, beams, columns, or the like. The mechanism is usable for releasing loads which are under tension and, in certain embodiments, also transmit compression and torsional forces. One mechanism includes a pair of pivoting plates connected to the ends of a bifurcated strap. The plates engage elongated surfaces on a root member connected to an opposite strap. An indexing arrangement is provided to prevent relative sliding movement. The plates are biased for outward movement. Outward movement is prevented by releasable securement links or straps. An alternative form of securement is provided in the form of a sliding enclosure. An alternative embodiment for flexible or rigid members is provided in the form of a central root surrounded by outwardly pivoting leaves. Pivoting members connected to the leaves engage projections on the root member.