Abstract: The invention provides a bolting installation apparatus comprising a base having a pair of parallel cylindrical rods held between two end plates; an intermediate carriage slidably mounted on said rods; a drilling unit carriage having at least one first rod and at least one second rod spaced apart from said first rod; a drilling unit slidably mounted on said second rod and said intermediate carriage slidably receiving said first rod of said drilling unit carriage; at least one moving means to move each of said base, said intermediate carriage and said drilling unit carriage relative to each other.

Abstract: The present invention relates to improvements in the operation and construction of roof bolters or roof bolt installation apparatus. The improvements comprise a roof bolter constructed so that the critical moving parts of its timber jack, feed frame, feed carrier and rotational unit are comprised of a rod and sleeve construction. Such construction allowing the protection of surfaces. The construction also includes feature of a spaced apart rod and sleeve construction which allows motive power units to be housed within the confines of the timber jack and feed carrier. The spaced apart arrangement also provides stability to the roof bolter.

Abstract: A radiation pyrometer for a gas-turbine engine has a fibre-optic cable with three discrete bundles. At one end of the cable, the bundles, are arranged in a jig with one bundle being positioned centrally, being the other bundles which are of C-shape and located on opposite sides of the central bundle. A converging lens focusses radiation from the turbine blades onto the end of the cable, the ends of the bundle being oriented such that each bundle receives radiation from a different region spaced along the length of the blades. At the other end of the cable, each bundle is connected to a respective detector.

Abstract: A pyrometer for viewing the blades of an engine has a forward lens which produces a first image of the blades in an image plane P.sub.1. Rearwardly of the image plane P.sub.1 is an assymetric faceted lens assembly having a central region with a long focal length, and an outer annular region of shorter focal length. The outer region of the rear lens assembly forms a second image of the first image in a second image plane P.sub.2. The inner region forms a third image of the forward surface of the first lens in the second image plane P.sub.2. A disc mask is fixed centrally to the forward surface of the first lens, and an annular mask is located in the first image plane P.sub.1. The forward end of a fibre-optic cable is located in the second image plane P.sub.2 and comprises a central bundle of fibres which receives the second image, and two outer bundles which receive different parts of the third image.

Abstract: A radiation pyrometer has an inner tube with a lens mounted in a rear portion which is stepped to a forward portion of reduced diameter that is open at its forward end. An outer tube extends coaxially around the inner tube and is separated from it by an annular gas passage. The outer tube has an aperture at its forward end that is smaller that the external diameter of the forward end of the inner tube and larger than the internal diameter. The outer tube has gas inlets into the passage which are located rearwardly of the forward end of the inner tube, the area of the gas inlets being greater than the gap between the forward end of the inner tube and the outer tube. Gas flows through the inlets, along the passage, across the forward end of the inner tube and out the aperture, thereby setting up a substantially constant pressure in the rear portion of the inner tube and reducing the entry of contaminants.