Abstract: An automatic machine for operating upon a work piece at a predetermined ption with respect to a pre-selected physical feature, for example an edge, of the work piece. The machine scans the work piece and transmits signals corresponding to the co-ordinates of the physical feature to a computer. The computer thereafter controls in accordance with the signals received from the scanning head the position of the operating head, so that the operating head can operate upon the work piece at the pre-determined position with respect to the pre-selected physical feature.

Abstract: An electrically initiated igniter having good resistance to accidental looltage triggering is disclosed. The igniter comprises a layer of pyrotechnic mixture packed between two initiating electrodes, advantage being taken of the dielectric properties of a selected component of the mixture to provide a high d.c. resistance between the electrodes, which d.c. resistance so limits the current flow through the layer, resulting from an applied electrical stimulus, as to prevent firing of the mixture at all applied voltages which are less than that at which dielectric breakdown of the layer occurs. When fired, the combustion proceeds without shattering and the igniter is particularly suitable for igniting materials requiring non-brisant initiation.

Abstract: There is disclosed an apparatus for defining a vertical axis by means of a reely suspended optical system acting as a plumb line. In equilibrium, the optical system has a vertical optical axis about which real images can be detected at distances of the order of a thousand feet above or below the optical system. The apparatus is capable of considerable accuracy in generating a vertical axis for alignment purposes.

Abstract: A mechanical displacement meter prover has a displacer which is devised to facilitate operation with gas flows. The displacer comprises a pair of longitudinally spaced, transverse sealing members, such as a pair of inflated elastomer spheroids, between which is a reservoir of lubricating fluid. Each sealing member is exposed to the fluid as the displacer travels through the prover, the fluid acting both to lubricate the displacer and to assist in sealing the displacer against the propelling gas flow.

Abstract: The disclosure concerns a hydraulically driven impactor in which the operng cycle of a reciprocating piston is determined by the retraction velocity and displacement of the piston itself. Energy is conserved and heat dissipation minimised by the utilization of hydraulic spring accumulators to decelerate the piston. The drive to the piston is switched into a forward direction at such a point in each displacement cycle that the rebound energy of the piston is always re-absorbed into the drive fluid. The impactor operates at optimum acceleration and frequency at all times, whether or not impact occurs, and this feature combined with high energy conservation makes the impactor particularly suitable for use in a full-face tunnelling machine where high power density is required and individual impactors are often constrained to operate without impacting the rock face for considerable periods.

Abstract: In an electric cell having a solid electrolyte which bounds on one side a mpartment for liquid anode and on its opposite side a compartment for liquid cathode, the liquid anode compartment is made of very limited capacity. The bulk of the liquid anode required by the cell is held in a reservoir and fed to the liquid anode compartment by a capillary duct to provide a restricted feed which limits the flow of liquid anode therebetween. The reservoir may be disposed within the cell, or outside the cell, and may supply liquid anode to several cells.

Abstract: The invention concerns an apparatus for establishing an anchorage in the of a liquid. The apparatus comprises essentially a substantially hollow structure into which solids from the liquid bed are induced as solids in liquid suspension. When the apparatus is being used as an anchoring device the design is such that as solids from the liquid bed are induced into the substantially hollow structure they fill or partially fill the structure which then proceeds to bury itself into the liquid bed thereby establishing an anchorage.

Abstract: A sodium-sulphur cell is provided having a ceramic spacer means disposed in he liquid sulphur compartment to provide a region substantially free from cathodic reactions. The spacer means is disposed adjacent to materials likely to be adversely affected by said cathodic reactions, such as glass seals used to join the solid electrolyte to a ceramic support member, or a metallic end cap provided to close the liquid sulphur compartment.

Abstract: In an electric cell having a solid electrolyte and employing sodium as the iquid anode and sulphur as the liquid cathode, the liquid anode is contained in two compartments separated by a corrosion resistant barrier. Liquid anode is arranged to flow between the compartments through a flow restrictor which permits a rate of flow sufficient to meet the normal charge and discharge requirements of the cell but limits higher rates of flow.One of the compartments has a very limited capacity for liquid sodium and is disposed about one side of the solid electrolyte to define a wicking space to constrain liquid sodium to flow over the solid electrolyte. The other compartment provides a reservoir for containing the bulk of the liquid sodium.In the event of damage to the solid electrolyte, only a very limited amount of liquid sodium is readily available to mix and react with the liquid sulphur.

Abstract: A hydraulically actuated driving tool is provided with a ground engageable member which is driven into the ground by the action and reaction of a drive mass which is free to slide within the tool and which is repetitively forced away from and back to the ground engageable member in a manner determined by a hydraulic control system. Each repeated cycle of operation engenders two separate forces to drive the ground engageable member into the ground, one being the force exerted by high pressure fluid in the hydraulic control system when the drive mass is forced away from the ground engageable member and the other being the force exerted when the drive mass impacts back upon the ground engageable member. A switch means is provided whereby the returning drive mass initiates the next cycle of operation of the hydraulic control system.

Abstract: A radiation filter, for a gas detector, comprising an optical interferome having in each of first and second physically separated optical paths therethrough a gas cell containing a quantity of the gas to be detected; there being a difference in pressure between the quantities of gas in the two gas cells; the gas cells being of substantially equal lengths in the direction of the optical path therethrough; and the interferometer being arranged so that in the absence of the gas cells there is zero path difference between the said first and second optical paths through the interferometer.

Abstract: A method for the diminution of high temperature oxidation in an iron alloy ontaining chromium consisting of at least partially enclosing the alloy and a volatile inorganic boron compound, heating the boron compound and allowing the volatile constituent of the boron compound to contact at least one surface of the alloy.

Abstract: A detection device for sensing the passage of a discrete body through a cely fitting pipe comprises a constriction which, by interaction with the moving body, produces a change in a mensurable parameter in the region of the constriction, which change is sensed by a suitable detector.The invention is particularly applicable to detection of displacement members transported by fluid flow through the pipelines of meter provers used to calibrate fluid flowmeters.

Abstract: A sodium-sulphur electric cell is provided having a sulphur compartment in hich a current collector of hollow form extends. The space inside the current collector is used as an expansion space for products arising from reaction of sodium and sulphur. The walls of the current collector may be tapered to arrange that the current density along it is substantially constant.

Abstract: Apparatus, for storing energy from incident electromagnetic radiation, hag an electromagnetic radiation energy absorbing means; an optical reflection filter having a substantially greater reflectance of electromagnetic radiation of longer than of shorter wavelengths and a substantially greater transmission for electromagnetic radiation of visible and shorter wavelengths than it has for electromagnetic radiation of wavelengths greater than those of the visible spectrum, the filter being positioned relative to the said energy absorbing means so that incident electromagnetic radiation can pass through the filter to reach the absorbing means, but energy re-emitted by the absorbing means in the direction of the filter is substantially returned by the filter to the absorbing means; an output channel for drawing off energy from the energy absorbing means; and means for restricting the outflow of energy otherwise from the energy absorbing means.

Abstract: A method and apparatus is described for filling an electric cell which coises a compartment for receiving a liquid electrode, an electrolyte, and a constraining means in the compartment for constraining the liquid electrode to wet a surface of the electrolyte. The method comprises the steps of introducing liquid electrode material into the compartment, thereby to contact the constraining means with the liquid electrode material. The liquid electrode material is then subjected to a pressure sufficient to force the liquid electrode material to penetrate the constraining means and thereby wet the electrolyte. The gas is maintained in the cell to ensure that the liquid electrode material remains in the constraining means.

Abstract: The invention comprises an afocal lens system having unitary magnification hich is either positive or negative and suitable for indicating departures of a reference point or a reference axis respectively from coincidence with a relatively fixed datum axis. The reference point or axis is included by the axis of the lens system, and the datum axis is defined by a line through an object and the zero position of an image of that object produced by the lens system. The lens system indicates the said departures from coincidence by means of shifts of the image from the zero position. The positive magnification afocal lens system is sensitive to tilt but insensitive to displacement, whereas the reverse is true of the negative magnification version. This feature allows tilt and displacement to be monitored separately.

Abstract: A radiation source comprising a lamina of amorphous or predominantly amorus polymer material having appreciable electrical charge mobility and a low ionization potential; a strong electron donor; a strong electron acceptor; and preferably at least one fluorescent additive; electrical connections being provided by which an electric current may be passed through the thickness of said lamina to excite radiation therefrom.

Abstract: In a sodium-sulphur battery cell of tubular form, the sulphur compartment provided inside a tubular solid electrolyte. The sodium compartment is provided by the annular space between the solid electrolyte and a metal casing. A carbon current collector extends into the sulphur compartment. A stainless steel mesh disposed in the sodium compartment adjacent to the solid electrolyte acts as a wick for sodium.

Abstract: An arrester for a discrete body being transported through a closely fitting ipeline by liquid flow, consisting of a final length of pipe with enlarged bore which gradually tapers to a minimum cross section at its closeable end. When the end is closed, a discrete body carried axially into this enlarged bore is decelerated by the action of liquid in the end bore being forced back past the body. Suitable shaping of the taper governs the rate of deceleration.The invention is particularly applicable to the arrestment of displacement members used in flowmeter provers and provision has also been made for launching an arrested displacement member back into the prover pipe with an acceleration rate governed by a further region of enlarged bore but with reverse taper.