Abstract: A perfluoroalkylene .alpha.,.omega.-diacetylene compound having a fluorocarbon chain of from 5 to about 20 carbon atoms between two acetylene end groups, and a method of forming same by first reacting perfluoroalkylene diiodide having the formula I(CF.sub.2).sub.n I, wherein n is a whole number from 5 to about 20, inclusive with bis(trimethylsilyl)acetylene, and converting the reaction product to the diacetylene with KF. The diacetylene has the general formula HC.tbd.C(CF.sub.2).sub.n C.tbd.CH, wherein n is as set forth above, and it can be polymerized to produce a clear, hard, cross-linked resin suitable for use as a coating on bearings and in the manufacture of aircraft windshields. Monofunctional counterparts of the HC.tbd.C(CF.sub.2).sub.n C.tbd.CH compounds can be formed by substituting perfluoroalkyl primary iodides for the diiodides in the above-described reaction.

Abstract: A spring assembly for use in place of the spiral tension springs in conventional spring-loaded counterbalancing systems for garage doors. It is made up of a compression spring and traveling pulley in a tubular housing, the compression spring being mounted above the pulley. A cable extends around the pulley from an anchored end to interconnection with the kicker assembly of the mounting hardware for tension springs in an ordinary garage door counterbalancing system so that closing of the door causes the cable to pull up on the pulley and compress the spring. There is virtually no possibility that the compressed spring will rupture and emit flying fragments, but even if this occurred the housing would prevent the escape of such fragments to the surroundings.

Abstract: A crawler tractor with a dozer blade and fitted with accessories to loosen the ground in the strafing pit area of an Air Force gunnery range and simultaneously remove from the ground rocks the size of a man's fist and larger and spent projectiles. The tractor is provided with an electromagnet positioned ahead of the dozer blade. Positioned to the rear of the tractor, and pivotally attached to its frame by drawbars, is a chisel bar with a plurality of chisel blades. Just ahead of the chisel bar is a rock rake having a spine from which extend a plurality of forwardly projecting tines. The rake is supported with its tines at such an angle that their tips barely scrape the surface of the earth. Ahead of the rock rake, there is a drag consisting of a section of railroad rail suspended from the drawbars of the chisel assembly at a height sufficient to just scrape the surface of the ground during operation of the tractor.

Abstract: A type of tape which embodies two faces each containing a pressure sensitive adhesive coating. One face has a coating with a lesser degree of adhesive capability than the coating on the opposite face. The latter can be placed on a first material to form a pattern thereon, thus leaving the face with the coating having the greater degree of adhesive capability exposed. An object having a meeting surface may then be applied to the exposed coating. When that object is removed from the first material, the tape pattern is transposed to the backside of said object. This eliminates the necessity of using measuring tools and conventional methods to find and transpose the pattern from the first material to said object.

Abstract: A solar-powered motor with a wheel-like rotor having a rim separated into hollow compartments. The rotor is designed to revolve around a horizontal axis while containing a volatile liquid in some of its rim compartments. The rotor has a hub, also with separate compartments, and hollow spokes interconnecting the hub with the rim compartments. The interior of the rotor is designed to receive a compressed gas in its hub and sequentially route it, through the hollow spokes, to rim compartments on one side of the rotor axis. When the compressed gas makes contact with the liquid surface in that part of the rim it exerts pressure on that surface. The pressure on the liquid surface forces the liquid to the opposite side of the rotor and into the rim, through an interconnecting series of passageways in the spokes and hub, at a level higher than its original level.

Abstract: A lawn mower has a transverse cutting bar, but instead of a reel-type cutter to cooperate therewith, a rotary cutter is employed that has a plurality of curved cutting edges that maintain constant contact with the transverse cutting bar and repeatedly traverse the cutting bar with the cutting bar positioned more or less tangentially of the curved cutting edges. In all embodiments of the invention, the cutting edges are substantially circular and concentric as viewed along the axis of the rotary cutter, and in at least most embodiments the rotating cutting edges eliminate hazard to the operator by pushing away out of harm any part of the operator's body that may inadvertently intrude into the zone of the cutting operation. In the presently preferred embodiment, the cutting edges are the peripheral edges of a plurality of spaced discs that are inclined to wobble along the transverse cutting bar.

Abstract: A finely woven, shrinkable fabric of square-weave pattern suitable for use in the covering of aircraft frames. The fabric is formed entirely from high tenacity polyester filaments, preferably of 70-denier size. When so formed, it is significantly superior in properties of strength and elongation under load to fabrics made from regular tenacity, 70-denier polyester filaments. Such 70-denier fabrics made from regular tenacity polyester filaments do not meet the FAA requirements for aircraft cover utility, however. Consequently, although regular tenacity polyester filament fabrics have heretofore been used for aircraft cover purposes, in order to meet FAA requirements for such usage they have had to be substantially coarser and heavier than the high tenacity, 70-denier fabric of this invention.