Abstract: A method for isostatic pressing of formed powder, porous powder compact, and composite intermediates and the intermediate and final products produced thereby. The method includes the steps of:(A) coating the exposed surface of the formed powder, porous powder compact, or composite intermediate with a flowable film-forming material capable of forming a solid continuous impervious flexible film; then(B) solidifying the coating of step (A) on the surface of the intermediate to form a coated intermediate; and(C) subjecting the coated intermediate of step (B) to a uniformly applied pressure exceeding atmospheric pressure to produce a flexible coating formed directly on the parts to be isopressed, permitting small parts or parts with complex shapes to be coated individually or in bulk.

Abstract: Lens grinding or polishing pads are provided, characterized by a bonding system which permits them to be quickly and easily contact-adhered to the surface of a lens finishing tool, but which pads at the same time display strong resistance to lateral displacement during use. These pads can also be readily and easily stripped from the finishing tool without deformation or damage to them.

Abstract: A method and apparatus for indicating the time-break on a seismic record wherein the time-break is marked in response to the rupture of an electric circuit by the explosive charge used to generate the seismic waves. The preferred rupturable electric circuit is connected to the same energy source as the electric detonator used to initiate the explosive charge and the preferred electric detonator is one connected to a high frequency A.C. firing energy source through a transformer, the rupturable electric circuit being the primary or secondary circuit of the transformer.The method is more accurate than the present method of marking the time-break at the initial application of current to the detonator.

Abstract: Low level remotely generated control signals are amplified at a local ignition site using a local power source and the amplified control signals are used to charge a local energy storage device. Thereafter firing control signals (e.g., controlled duration suppressions of the remotely generated control signals) are detected and used to control discharge of the thus stored energy through an electrical ignition device.

Abstract: An inductive coupling device is provided wherein the transmission of energy through the device is controlled by the application of a steady magnetic field within the magnetically permeable core of the device, transmission being inhibited at high magnetic field intensity and restored when the magnetic field intensity is reduced to a low value. The device is especially advantageous for the safe coupling of ignition elements, such as blasting detonators, to an a.c. firing energy source.

Abstract: A chain tensioning device comprises a pair of arms 2, 3 which are pivoted together and urged apart so that the arm 3 applies a tensioning force to a chain by means of a spring loaded cam block 5. A catch disc 9 and rod 8 arrangement is provided to prevent return movement of the spring loaded block and hence collapse of the arm 3 under load reversals of the chain.

Abstract: A chain tensioning device comprises a pair of arms 2, 3 which are pivoted together and urged apart, so that the arm 3 applies a tensioning force to a chain, by means of a block 9 biased by a compression spring 10 axially along the arm 2 in conjunction with links 14 coupled between the block 9 and the arm 3 and serving to pivot the arm 3 relative to the arm 2, in response to such spring biased axial movement of the block 9. A catch disc 12 and rod 6 arrangement is provided to prevent return movement of the spring loaded block 9 and hence collapse of the arm 3 under load reversals of the chain.

Abstract: A composite material and method of preparing same for use in prosthetic dentistry. The composition includes silica glass containing between about 8.0-30% on a weight basis of alkaline earth metal oxides and/or alkali metal oxides in solution selected from the group consisting of calcium oxide, magnesium oxide, sodium oxide, potassium, and lithium oxide. In one form of the invention, a methacrylate resin is coupled to the silica glass by a silane mixture. The invention includes the method of forming the composite material through both a cold curing system and a heat cured system into a composite veneering and tooth material which is useful in forming crowns and other dental restorations as well as artificial teeth requiring aesthetic appearance of normal dentition. The finally formed dental material shows a high hardness factor in combination with a high wear resistance.

Abstract: A retroreflective device is disclosed comprising a convex-concavo lens having a cube-corner array extending across its concavity. The device returns in the same direction from which it is received a large proportion of incident light. The lens body is adapted with respect to reflected light to indicate a larger than actual area of the cube-corner array. The retroreflective device may be used as a marker, such as a roadmarker, the convex side of the lens body being exposed to receive the incident light.