Abstract: A gate for a gate valve is formed with an undercut groove in which is inserted a screw-threaded coupling member formed with a screw-threaded hole which is a clearance fit into the groove. The screw-threaded hole is plugged then the gate containing the coupling member is inserted into a mould into which coating material in a fluid state is introduced under pressure so as to cover the gate and penetrate into the clearance gaps between the adjacent faces on the coupling member and the groove in the gate. The invention also comprises a coated gate formed by the process described.

Abstract: A shaft seal incorporates a casing formed with a stepped bore both diameters of which are greater than the diameter of the shaft fitted to the bore. A bearing sleeve fitting the shaft is located in the smaller diameter portion of the bore. A seal-carrying ring held captive within the larger diameter portion of the bore is formed to support at each end a sealing ring in contact with the shaft and a sealing ring located between the outer surface of the ring and the casing.

Abstract: A valve incorporates a float chamber containing a float, and an air chamber above the float chamber containing a valve element movable vertically between a port in the bottom of the air chamber communicating with the top of the float chamber and an air vent in the top of the air chamber the float and the valve element being connected by a push rod passing through the port. The push rod has a cross section presenting several lobes. A plain tubular guide forms at least part of a passage between the float chamber and the air chamber terminating at the top end in the port. The push rod passes through the tubular guide, the lobes being a sliding fit therein. The valve element may rest in a cup-shaped cage within the air chamber. The upper end of the push rod may be slotted to permit it to straddle the bars of the cage and enter the cage so as to engage the valve element.

Abstract: The invention relates to a non-invasive oximetry process for determining the value of oxygen saturation of the blood of a subject. In some ear oximetry processes, light at two or more frequencies is transmitted through the ear lobe or pinna of the ear of a subject, and the intensity of the transmitted light is measured on the other side of the ear lobe. These processes are affected by such variables as depth of blood in the ear lobe or pinna and differences in the total hemoglobin concentration in the blood. Applicant has discovered that inaccuracies caused by these variables can be eliminated or greatly reduced by taking the derivative of the intensity of the transmitted light, and processing the values of these derivatives in association with a set of predetermined pseudo coefficients by applying these to newly developed relationships disclosed in the specification. The result of such processing yields the value of oxygen saturation of the blood of the subject.