Abstract: A method and apparatus is disclosed for determining physical characteristics, such as defects, in the outer surface of an elongate object, wherein the object to be inspected passes through an aperture of a mirror surface which is a conical surface of revolution. Light directed onto the mirror surface in an axial direction is reflected by the object surface, imaged, and analyzed to determine a physical characteristic of the object surface.

Abstract: Method and apparatus for inspecting threaded objects and for determining the depth of blind holes. For inspecting threads, a light source is provided for illuminating threads of a threaded object. A lens forms an image of the illuminated threads. A detector having a light sensitive area sufficiently small to resolve the thread image is provided to detect the image and an output signal is produced in response to the incident image light. The output signal is analyzed to determine the quality of the threads. For determining the depth of a blind hole, a light source forms a spot on the bottom of a blind hole in an object and the lens forms an image of the spot. Means are provided to detect the spot image to produce an output signal responsive to the incident image light. Means are provided to analyze the output signal to determine hole depth.

Abstract: A method of determining physical characteristics of a surface. Light or other electromagnetic radiation is directed onto a first portion of a surface and the reflected radiation is received such as by a photodiode. The radiation is also directed onto at least two further portions of the surface and located on either side of and proximate to the first portion. The radiation reflected by the further portions is also received. The radiation reflected from the first portion is compared with the radiation reflected from the two further portions. The radiation and comparison steps are repeated and the comparisons are used to determine a physical characteristic of the surface, such as the presence of one or more flaws. In another embodiment, light or other electromagnetic radiation is used to determine object dimension, such as bore dimension.

Abstract: Catalytic gas sensors comprise a noble metal filament onto which is applied alumina having a particle size of not greater than 100 A and a catalyst material is impregnated into the dried alumina. The alumina may be dried by passage of an electric current through the filament and, prior to coating the filament may be stabilized by coating with a thermally decomposable aluminium salt and decomposed by passing a pulsed electric current.

Abstract: A spray of ink, paint, or other marking liquid is formed and sprayed through a stencil member for marking a part with a stencil character. Various means are provided to periodically move the stencil member for removal of marking fluid to keep the system clean. In one system, the stencil member is rotatable and marking fluid is removed periodically by centrifugal force by rotating the member at a sufficient speed. Removal of the marking fluid may be facilitated by the application of solvent or fresh marking fluid. In another embodiment, the stencil member is moved to a marking liquid removal location where the marking liquid is removed by suction, solvent action, and the like. The removed marking liquid may be collected by providing an absorbent member positioned to receive the removed liquid, or by providing collecting gutters or the like.

Abstract: Weighing apparatus and method. A plurality of weigh members are moveable in sequence in a continuous path. Each weigh member receives an item to be weighed and includes a member which is moveable in response to the weight of the carried item. Preferably, the moveable member is elastically deformable. When an item to be weighed is deposited on a weigh member, the moveable member moves in response to the weight and then "springs" back and so on in an oscillating fashion. The weigh members, each carrying an item to be weighed, are rapidly moved in sequence along the continuous path to a weighing location and the time, while short, is sufficient to permit oscillating movement of the moveable member to substantially cease by the time that the weigh member arrives at the weighing location.

Abstract: A method and devices for sensing changes in separation of a first member relative to a second member, as well as variables causing such changes is disclosed. Electromagnetic waves diffracted by means included in said first member interact with waves from means included in said second member to form a characteristic interference pattern. Measured changes in this pattern allow determination of changes in separation.