Abstract: A laser consolidation apparatus for manufacturing precise three dimensional structures disclosed. The apparatus comprises means for feeding a stream of material to an area on a surface to be built up, at an angle normal to the surface and means to direct a converging laser beam on the surface at an angle of 25 to 30° to the normal to the surface from a plurality of directions surrounding the material feed. Discrete mirror segments direct the laser beam on to movable plane mirrors producing reflected beams which combine to illuminate an area on the work surface.

Abstract: A device for regulating the flow of particulate material comprising a first, inlet conduit having an outlet end, and a second, outlet conduit aligned with the first conduit and having an inlet end sufficiently close to the outlet end of the first conduit as to receive at least a portion of a particulate material flow exiting the first conduit. The lateral relationship of the adjacent ends of the two conduits is adjusted to change the area of the inlet end exposed to material leaving the first conduit to adjust the flow of particulate material through the second conduit; material which does not enter the second conduit is recycled. The device is particularly useful for regulating the flow of small quantities of metal powder being fed to a laser consolidation process. The invention also includes the method of regulating by lateral adjustment of the adjacent conduit ends.

Abstract: A laser consolidation apparatus for manufacturing precise three dimensional structures disclosed. The apparatus comprises means for feeding a stream of material to an area on a surface to be built up, at an angle normal to the surface and means to direct a converging laser beam on the surface at an angle of 25 to 30° to the normal to the surface from a plurality of directions surrounding the material feed. Discrete mirror segments direct the laser beam on to movable plane mirrors producing reflected beams which combine to illuminate an area on the work surface.

Abstract: A laser consolidation methodology and apparatus for manufacturing precise three dimensional structures are disclosed. In the disclosed process, a plurality of beams of laser energy are arranged to impinge a circular area on a substrate, at an angle in the range of 25° to 30° to the normal to the substrate, melting a hemispherical region of the substrate. Powdered material is supplied to the melted region of the substrate in a direction substantially normal to the substrate. The rate of material feed is controlled so that the added material melts and forms together with underlying material a molten zone maintained spherical under the influence of surface tension. The substrate is moved relative to laser beams and material feed at a controlled rate so as to create a ridge of desired shape on the substrate, the top surface of which has a semicircular cross-section.

Abstract: A device for regulating the flow of particulate material comprising a first, inlet conduit having an outlet end, and a second, outlet conduit aligned with the first conduit and having an inlet end sufficiently close to the outlet end of the first conduit as to receive at least a portion of a particulate material flow exiting the first conduit. The lateral relationship of the adjacent ends of the two conduits is adjusted to change the area of the inlet end exposed to material leaving the first conduit to adjust the flow of particulate material through the second conduit; material which does not enter the second conduit is recycled. The device is particularly useful for regulating the flow of small quantities of metal powder being fed to a laser consolidation process. The invention also includes the method of regulating by lateral adjustment of the adjacent conduit ends.

Abstract: A process of the kind used for producing or repairing a turbine or compressor or fan blade by laser consolidation wherein a laser beam is moved relative to a metal surface and a stream of metal is supplied to the surface via a supply tube, so that said laser beam melts a thin layer of the metal substrate and also melts the metal being delivered to the substrate and thus forms a band of fused metal on said surface, the process being repeated until a desired blade is built up or repaired. The invention is characterized in that the laser beam is orientated at an acute angle to the surface. The supply tube may deliver the metal substantially along a path normal to the surface, with the laser beam being one of a plurality of laser beams each orientated at an acute angle to the surface and spaced around the supply means.

Abstract: A process for producing a cutting die having a metal base which carries a sharpened ridge extending along a predetermined path thereon, in which a supply of powdered metal and a laser beam are moved along the path so as to surface melt a thin layer of the metal base with the metal powder and thus form a band of fused metal powder along the path, this step being repeated to form additional layers metallurgically bonded to the base and to each other, until a ridge of metal is formed. The ridge is then sharpened to suit it for use in cutting. The ridge may have a top surface of harder material than the inner part of the ridge. The laser and powder delivery movements may be controlled by a CNC (computer numerical control) motion system. The invention includes novel dies produced by this process.

Abstract: A method of manufacturing electrically conductive elements such as electrodes for EDM, ECM or other electromachining processes comprises the steps of designing a digital representation of the element, making a three-dimensional replica of the element from an intermediate material, e.g. a polymer, based on the digital representation, and coating the replica with a layer of a good electrical conductor. The replica is made using a tool-less prototyping process. The method is faster and less expensive than conventional machining of copper or graphite EDM or ECM electrodes, especially those having an intricate shape.

Abstract: In a method of grinding a workpiece employing a metallic grinding wheel sorting a non-conductive abrasive medium, a cathode is provided in spaced relationship with the abrasive surface so as to define a gap therewith. Electrolyte is caused to flow through the gap, and a low direct current is passed between the grinding wheel and the cathode through the electrolyte so that a small amount of metal is continually removed from the grinding wheel so that material trapped in the abrasive surface is dislodged and flushed away by the electrolyte flowing through the gap.

Abstract: A chain saw guide bar comprises an elongate plate member having a rounded tip and providing guide means for a saw chain around its periphery. The plate member has a network of intercommunicating passageways provided between its lateral faces and extending between multiple points on its upper and lower periphery so as to permit the flow of fluid therebetween. This arrangement provides efficient transfer of lubricant or other medium to all points on the guide bar periphery and can be up to 30% lighter than conventional designs.

Abstract: A method of laser machining hard material workpieces comprises the steps of applying a high energy, short duration laser pulse to a succession of spots on the surface of a workpiece, the duration, wavelength, and energy and of each laser pulse being such that said energy is substantially completely consumed in vaporizing a controlled quantity of material from the surface of the workpiece, the vaporized material creating a plasma cloud over each spot, each successive spot being sufficiently displaced from the previous spot to minimize the effect of the plasma cloud thereon, and the spots eventually overlapping so as to cover the whole of a desired area to be machined. In this way, hard materials such as ceramics can be machined to high precision with minimal formation of microcracks.

Abstract: An apparatus for injecting liquids into a body without using hypodermic needles, the liquid being ejected from a small orifice in a probe at a velocity which will penetrate the surface of a body against which the probe is placed. The apparatus ejects a specific small volume of the liquid under a very high initial velocity and pressure followed by the ejection of the main charge of liquid at a lower velocity so that the liquid flows into the channel caused by the initial penetration without penetrating to a greater depth. The probe is connected to a hand-held portion whose other end is attached via a flexible tube containing a suitable hydraulic fluid to two remote pressure intensifiers, one of which creates the required high initial pressure for a short period of time and the other of which provides the pressure necessary to eject the main charge of liquid at a lower velocity.

Abstract: A two-part concave-convex rupture disc for use in a safety pressure relief device comprises one part which is perforated with lines of small holes that introduce controlled weakness in the disc and the other part which acts as a seal. When the pressure in a fluid on the convex side of the discs exceeds a predetermined limit, the discs will reverse their direction of convexity and the metal of which the perforated disc is made will tear cleanly along the lines of perforation and rupture so as to release the fluid in which the excess pressure occurred. The pressure at which the rupture occurs is determined by the choice of the size and spacing of the perforating holes, as well as the choice of the thickness, the material of which the discs are made, and the pressure used to form the discs.

Abstract: A method and apparatus for electrolytically assisting the mechanical shaping of a workpiece is provided which is particularly useful for precision machining. A tool is used comprising an electrically conductive (copper alloy) tool shank, a cutting tool of an electrically insulating material (reinforced ceramic), and means for flooding a gap, between the tool shank and the localized electrically conductive surface layer to be shaped, with a stream of electrolyte. With the electrolyte flowing, and a low voltage, direct current applied across the gap using the localized, electrically conductive surface layer as the anode and the tool shank as the cathode, the structure of the localized, electrically conductive surface layer of the workpiece just ahead of the tool is weakened structurally sufficiently to be removed easily by the cutting tool in discrete form and carried away from the tool by the stream of electrolyte.