Other

C.a.v. Limited

Dexter William Smith

Adrian C Brennan

Brian Leslie Miles

William J Arrol

Terence Leslie Tombs

In manufacturing a silicon nitride product of complex shape and uniform density, a mixture of silicon nitride in powder form together with a fluxing agent and a temporary binder is first produced. From the mixture a preform of substantially uniform density less than the density of the required product is then formed, the dimensions of the preform in the direction of subsequent hot pressing to the dimensions of the final product in the same direction being arranged to be in the ratio of the preform density to the required final density. The preform is then heated to remove the temporary binder and is hot pressed in a die carrying punches which together form a cavity defining the shape of the required product, the preform shape not conforming to the die cavity.

Method of manufacturing silicon nitride products

An ignition aid for internal combustion engines includes a sintered refractory ceramic composite heating element having a high resistance central portion interposed between a low resistance terminal end portions. The heating element is positioned in a hollow electrically conductive body adapted to be removably inserted in an aperture in an engine. The heating element is disposed between and has its terminal end portions in electrical non-point contact with a bridge portion at one end of the hollow body and an electrode rod extending into the hollow body in sealed relation therewith. In one embodiment, the electrode rod comprises a pair of relatively movable parts, one of which is resiliently biased into engagement with the heating element by a resilient PTC resistance element electrically connecting the parts. In another embodiment, the heating element terminal portions are diffusion bonded to the electrode rod and bridge portion, respectively.

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Birmingham, United Kingdom

Dexter William Smith