Abstract: A plain machinery bearing having a working surface comprising poly cyano aryl ether, which working surface may further comprise additives including reinforcing additives selected, for example, from the group consisting of mica, carbon fiber, aramid fiber, metallic fiber and mineral fiber, and/or may further comprise friction and wear reducing agents. The thickness of the polymer may range from 0.1 to 1 mm when bonded to a steel, copper alloy or aluminum alloy backing as a solid bearing material, and from 0.01 to 0.05 mm when used as a thin overlay material on top of another bearing material.

Abstract: A system for machining a piston blank to a predetermined profile includes means for rotating a blank at a predetermined speed and means for moving a tool axially with reference to the blank. Digital processing means receives input data defining the required profile (or part only of the profile if the profile is symmetrical). In response to this data, to digital information on a channel corresponding to the instantaneous angular position of the blank, and to digital data on another channel corresponding to the instantaneous axial position of the tool, the processor outputs digital data defining the required position of the tool in the direction perpendicular to the surface of the blank in order to produce the required profile. The actuator control processor outputs a corresponding digital signal which, via a digital-to-analog converter, drives a tool actuator so as to position the tool correspondingly.

Abstract: A piston holding device in which a conical register is provided inside the skirt of a piston and is engaged by a conical locating surface on a tailstock. The tailstock may also include a ram which is adapted to push on the inside of a piston crown and force the piston against a headstock. The holding device is used during piston machining.

Abstract: A method of making a siliconized silicon carbide article by(i) injection-molding a mixture which comprises a major proportion of silicon carbide particles and a minor proportion of organic binder material, the mixture being flowable under heat and pressure,(ii) heating the molded article thus formed so as to remove the organic binder material from it and obtain a porous silicon carbide body containing elemental carbon, and(iii) impregnating the porous body with molten silicon to convert said carbon to silicon carbide which binds together the original silicon carbide particles,in which step (iii) is carried out by utilizing as a conduit for said molten silicon the sprue that is formed integrally with the injection-molded article in step (i).The method avoids excessive contact between the surface of the porous intermediate shaped body and molten silicon employed for siliconization, and so reduces the possibility of damage to that body while it is in the weakly bonded state.

Abstract: A method of bonding a component in a piston, involves the steps of coating the component surfaces to be bonded with an oxidation-resistant particulate material, preheating the coated component, placing the preheated component in a casting die and then casting an aluminum alloy around the component. The casting technique may comprise squeeze-casting.

Abstract: A porous body is formed around an element which has the shape of the desired cavity and the body is heated to a temperature such that the element melts and infiltrates the porous body at least in the immediate vicinity of the resulting cavity. The article may then, for example, be incorporated into a piston for an internal combustion engine so as to form a cavity in the crown region thereof.

Abstract: The invention relates to a piston for a cylinder of a two-stroke internal combustion engine, the engine having an auxiliary air inlet port which communicates with a cavity within the crown structure of the piston as the piston passes through bottom dead center. The air within the cavity is caused to resonate at high frequency, thereby enhancing the combustion process, enhancing low speed power, torque and eveness of engine running, and reducing or eliminating engine pre-combustion "knock".

Abstract: A method for the manufacture of piston rings from a metal strip, at least includes providing rings having a predetermined non-circular profile, by the metal strip being first bent to a uniform radius of curvature at least 2 percent less than the minimum radius of curvature in the predetermined profile, then the curved strip being bent back to increase the radii of curvature of all the constituent portions of the strip forming the ring to the desired values of the predetermined profile.

Abstract: Certain articles required to function in air at temperatures of 250.degree. C. or higher comprise very fine particles of vermiculite from which the interstitial magnesium ions have been at least partially removed and which has been swollen in water. These articles are not ordinarily exposed to water when in use, but if they are they are likely to disintegrate quickly because of the ready dispersibility of the vermiculite particles. By the invention, water-resistance is given to such articles by treating them with a solution of an aluminate salt e.g. NaAlO.sub.2 or a zirconyl salt e.g. ZrOCl.sub.2.

Abstract: Hydrostatic journal bearing assemblies are described which include a housing member having a generally circular bore therethrough, a journal bearing member having a bore therethrough for the support of a shaft, the journal bearing member being located within the bore of the housing wherein the journal bearing member comprises at least one generally annular sleeve portion, an increased diameter flange portion at the axially inner end of the journal bearing member, the journal bearing member being sealed against the ingress of pressurized fluid into a space between the bore of the housing member and the outer surface of the annular sleeve portion, the annular sleeve portion being pivotally supported intermediate the axially outer end of the journal bearing member and the flange portion and the bearing member having means for access of a source of pressurized fluid between the bore of the journal member and the shaft to be supported.