Abstract: This quick change mechanism is a single bolt-on attachment for standard hand held power driven circular saws, to thereafter quickly install and remove diamond arbor saw blades without using any tool. A disc with a raised protruding center body is shaped to fit a standard diamond center blade, which when pressed down over this center body, is centered flat against the upper surface of the disc. The blade is then locked in place by expanding opposite undercut sections, which include the two closest points of the diamond. These expanding sections have undercut slots just above the upper disc surface and serve to wedge the blade down when moved radially outward. These resulting two wedging and sliding locks of the undercut sections are integral with radially sliding members, which move in and out in complementary "V" slots cut into the blade holding disc.

Abstract: To eliminate the need for using a hand wrench or another hand tool to remove lock nuts, screws, or other fasteners, to be able thereafter to remove a circular saw blade from a powered hand or table saw, this quick change mechanism is installed on the shaft or arbor of the powered saw. There is a preassembly of: a splined and grooved circular saw blade holder; a complementary splined slide lock with upwardly extending spline finger, for axially sliding on the blade holder; an installation bolt passable down through this blade holder and this slide lock, having an axial spring receiving cavity in a tapered head, also having an allen wrench receiving cavity; a coiled spring to be received in this cavity; and a release button with depending spring legs terminating in feet for passing about this coiled spring and down alongside the blade holder, via grooves formed in the spline recesses of this blade holder.

Abstract: An embodiment of a quick change mechanism permits, without using hand tools, the very quick changing, in second, of circular saw blades and other spinning disc devices, which have diamond shaped arbor holes, in respect to the drive shafts of portable powered circular blade saws, and radial saws. No modification of most existing saws is required. At the location of the existing saw drive shaft, with its central threaded hole, the drive shaft bearing, and the saw body; this quick change mechanism is secured, using an installation bolt passing through it and into the central threaded hole of the existing saw drive shaft.

Abstract: In one embodiment of this quick change mechanism, a narrow six spline hub is installed in the arbor hole of a circular saw blade or other disc tool heads such as grinders, sanders and buffers. This hub slides onto a matching splined drive shaft in which a narrow section of spline lands has been removed circumferentially to fit the width of the splined hub that is secured to the circular saw blade. A fifteen degree rotation of this splined blade hub on this shaft aligns all the lands and grooves, thus locking the hub relative the longitudinal axis of the drive shaft. To continue the locking, by locking the hub in rotation relative to the shaft, a splined sliding collar with spline land extensions, serving as locking fingers, is interposed into the spline grooves of the drive shaft and also the hub grooves. A blind longitudinal hole in the drive shaft contains a compression spring and an unthreaded bolt.

Abstract: A passive system and related methods for detecting range and/or elevation of a target by using an X beam antenna system and by measuring the time delay between receipt of signals in the two planes of the X beam which are received directly from the target and by measuring the time delay between receipt of signals in the two planes of the X beam which signals are emitted by the target but reflected from a remote surface. By knowing these two time delays, the height of the antenna system, the fixed angle between the two planes of the X beam and the rate of rotation of the X beam, a direct calculation is established to determine the range and/or elevation of the target.

Abstract: A passive system and related methods for detecting the location of a plurality of N targets by using two X-beam antenna systems and by (i) measuring the time delay between receipt of signals in the two planes of each X-beam which are received directly from the target and by (ii) measuring the time delay between the receipt of signals in the two planes of each X-beam which signals are emitted by the target but reflected from a remote surface. By known these two time delays for each antenna system, the heights of the antenna systems, the fixed angle between the two planes of the X-beam for each system, and the rate of rotation of the X-beam for each system, a direct calculation is established to determine the altitude of each target as viewed from each of the two antenna systems. Bearing or azimuth angles are determined for each target at each antenna system, and the actual N target locations of the N.sup.

Abstract: The saw includes a sectional table top made up of one or more sections that may be opened to receive insertable conversion assemblies adapted to provide additional woodworking functions. A rotary saw blade is moveable reciprocatively with respect to the table top at selected angles of tilt and at selected heights. One or two rip fences are selectively positionable in parallel alignment with the rotary saw blade, and may be lowered to form lateral extensions of the table top. The table top includes dovetail grooves to receive attachment for a work piece clamp or an angle guide. A kerf guide is attachable to the rear edge of the table top.