Abstract: To reduce the amount of water or other surface material issuing at the periphery of an air cushion vehicle, a flexible barrier is suspended at the vehicle periphery lateral to the cushion containing means--usually a flexible skirt. The spray or other material is trapped between the vehicle periphery and the barrier, with water or other material dropping down and air venting through apertures at the top of the barrier. Weight can be added to the lower part of the barrier to assist in maintaining the barrier down.

Abstract: A matrix multiplexed display cell has thin film switch devices at matrix crosspoints to provide a turn-on threshold for the electro-optic liquid used in the cell. Each of the switch devices is a back-to-back pair of diodes. The cell is operated at low current so that the switch devices, which are deposited on glass, do not degrade rapidly in use.

Abstract: Two rigid bodies are hinged together by a pair of elastomer hinge elements each of which is fixed within one body and rotatably mounted relative to the other body. At the rotary mounting, the elastomer material is stressed by interengagement with the other body to produce reproducible bearing friction. Properties of the elastomer material are selected to adapt the material for the hinge function; the elastomer element is readily replaceable without the need to replace the rigid bodies.

Abstract: A paper pulp insulated cable of the kind having a plurality of conductors covered with paper pulp insulation. The insulated conductors are twisted into pairs, the pairs are stranded into units and the units are built up into cores, covered with, for example, a paper wrap, aluminum, steel sheath and a polyethylene jacket. The cable has a high density of conductors. Also a method of manufacturing such cables is described.

Abstract: In a thermal print bar for use in facsimile systems, an array of individually selectable electrical current paths are defined in a strip of resistive materials having a high negative temperature coefficient of resistance. In operation, the resistance of a selected current path is markedly reduced in contrast with the resistance of unselected current paths parallel to the selected path so that the parallel current paths do not experience joule heating. Electrical power saving and visual contrast result.

Abstract: An air cushion vehicle has a plurality of webs extending out between adjacent skirt members, with a solid or tubular peripheral member attached to the web members at their forward parts. The web members and the peripheral member guard the skirt against damage by debris, such as ice. The webs tend to ride up over an ice edge, while ice floes or similar objects are deflected by the peripheral member. The peripheral member can be in the form of a blade to cut off humps of ice on the top of an ice sheet or floe.

Abstract: In the packaging of devices, such as active and passive electronic devices, the devices can be selectively hermetically sealed or non-hermetically sealed, as desired, using to a large extent common apparatus. In the limit, only the fusion sealing for hermetic devices and plastic encapsulation for non-hermetic devices need be carried out on separate machines. This is obtained by use of a particular form of lead frame, common for both forms of devices, with common apparatus and steps prior to and following the sealing or encapsulation.

Abstract: A shield for protecting transformer wire has a cap which fits over and locates the shield relative to the transformer laminations, a side wall to protectively cover transformer wire wound on a bobbin and an integral flange to protectively cover transformer input and output wire. A deflectable locking piece integral with the side wall is locatable under a flange of the bobbin to lock the shield in place.

Abstract: For powder filling of cables, in a fluidized powder bed, it has been proposed to pass the cable core through the bed in a substantially closed condition. There is a limit to the number of conductors a core can have for effective filling. In the present invention the cable core is opened up into a number of core units by passing through an opening member. The opening member is freely ridable on the cable core and has a hole for each unit. The opener is held against a support member and an air bearing formed between the two members. Air is also usually fed to the holes in the opener member through which the core units pass to prevent flow of powder out from the bed. The opening member can be positioned in the fluidized bed or outside immediately prior to passage of the cable core through the bed. The units are each in a substantially closed condition in the bed and the units close to a single core also in the bed.

Abstract: An optical cable has a grooved central filament, the grooves following helical paths, the helices changing hand along the filament. In the manufacture of the filament, plastics is extruded past a fixed die and some way downstream, the filament is held and twisted first in one direction and then in the opposite direction so that the helical paths are introduced where the plastics exits the die. Dielectric optical waveguides are disposed in the grooves and the whole is surrounded by an extruded plastic sheath to produce an optical cable.

Abstract: Apparatus for loading contact pins into a loading fixture, the pins in two or more rows, has a magazine for holding pins in a plurality of vertically stacked rows. Automatic insertion members push pins from the magazine into the loading fixture. The number of pins, and disposition of the pins, in a row can be predetermined by a template. The pins are swaged at a position intermediate the ends and thus do not stack level in the magazine. The magazine is provided with a stepped formation so as to offset the effect of the swage and provide for pins to be horizontal at the levels at which they are to be inserted into the loading fixture. Small rings of solder can be positioned on the pins prior to insertion in the board.

Abstract: Each thick film resistive print element of a thermal print bar operated in a scan mode is series connected to a thick film switch which sets a voltage threshold to isolate the element from periodic scan pulses unless coincident with an element selecting data pulse in which case the thick film undergoes joule heating which causes it to switch and its series-connected resistive element undegoes joule heating.

Abstract: Each element of a display operated in a scan mode is series connected to a thick film switch which sets a voltage threshold to isolate the element from periodic scan pulses unless coincident with an element selecting data pulse in which case the thick film switches and the element, for example, a nematic liquid crystal cell, operates.

Abstract: An optical cable is assembled by inserting dielectric optical waveguides into periodically reversing helical grooves in the surface of a central filament. The invention is concerned with minimizing longitudinal tension in the waveguides. Powered rollers draw dielectric optical waveguide from fixed reels and delivers it, in a slack condition, to a guide unit which is mounted by means of a thrust bearing. The guide unit supports rods with apertures at their ends through which dielectric optical waveguide is guided, the rod ends being disposed within the grooves so that respective dielectric optical waveguides and grooves are maintained circumferentially coincident. Cable is drawn downstream of the guide unit to pull the filament and dielectric optical waveguides together at the guide unit and also to reciprocally drive the guide unit. As the filament, with dielectric optical waveguides positioned in its grooves, exits the guide unit, it is helically wound with tape.

Abstract: A rotary indexing apparatus for automatic insertion of devices on printed circuit boards has a main support member attached to the insertion machine and a circular locating and supporting member rotatably supported by the main support member. Apertures are provided in the circular member over which can be positioned printed circuit boards. Generally four such locations are provided, particularly for insertion machines with an inserting head which inserts devices at two positions successively. By indexing the table between each complete cycle, devices are inserted in two directions, at right angles to each other, by insertion occurring first at one location and then at another location after the circular member has been indexed.

Abstract: A scanning device for use in a facsimile system is formed on a semiconductor substrate. The substrate has an array of apertures, the boundary of each aperture presenting a pn junction which functions as a photodetector when appropriate bias is applied through sensing and addressing circuits. A light is directed through the apertures from one side of the substrate to be incident on a document located against the other side. The boundaries of the apertures are contoured so that the photodetectors intercept light reflected from the document but are shielded from direct light. In use, the document and the scanning device are slid past one another at a rate commensurate with the rate of operation of the addressing circuit.

Abstract: A telephone transmitter sub-assembly has an electret clamped between a pair of printed circuit boards. The electret conducting surface and printed circuit patterns on the boards have an overlapping arrangement at a planar junction. The arrangement connects a capacitor, of which the electret forms part, into an amplifying circuit.

Abstract: A multiple connector for releasably connecting a plurality of pairs of optical fibres having two connector members, one having an axially moveable member therein with a plurality of axial holes, the other member having a plurality of aligning members extending axially. When assembled, an aligning member is aligned with an axial hole. The aligning member has a central bore portion a close fit on an uncoated fibre and tapered bores leading into the central bore portion. The axially moveable member is resiliently biased to project from a front face of the related connector member. On assembly the axially moveable member is pushed back into the connector member to expose one set of fibre ends which enter the aligning members. The other set of fibre ends are initially positioned in the aligning members. Preferably holding members are attached to the fibres and inserted from the rear of each connector member. This permits rear insertion of fibres.

Abstract: A modified etch boat acts as a transfer device for transferring wafers, in bulk. An etch boat has a longitudinal hole through one wall near the top edge, the hole periphery extending into Vee grooves in the etch boat. With wafers in the grooves, a rod inserted through the hole prevents wafers from falling out. With wafers in a storage box, the modified etch boat is positioned on the storage box, the hole inverted, and then the rod inserted after the wafers have transferred. The etch boat can then be inverted over a furnace boat, for example. After positioning on the furnace boat, with the wafers lifted slightly, the rod is removed and then the etch boat lifted off. The reverse operation is used to transfer from a furnace boat.

Abstract: This invention provides a wire skinning machine for skinning the insulation of inner conductors of multi-wire cables. A machine embodying the invention has three main advantages. First of all uniformity. The use of the invention ensures that all cables and wires are cut and skinned uniformly. Secondly there are two speed advantages one that the machine can prepare more skinned wires of a single cable more accurately and in less time than manually and that the machine is able to handle a large number of cables at one time. To do this the invention provides in combination a means for clamping multi-wire cables a means for fanning the inner conductors into a single layer in approximately parallel relationship, means for cutting the conductors to length and means for cutting the plastic insulation surrounding individual conductors and finally further means for sliding the cut end portion of the insulation off the inner metallic core.