Abstract: A liquid crystal device comprises a liquid crystal cell including a layer of ferroelectric smectic liquid crystal material contained between two walls bearing electrodes and surface treated to give both an alignment and a surface tilt to liquid crystal molecules. The material adopts a C2 rather than a C1 arrangement by arranging the surface pretilt &xgr; and the ratio of azimuthal to zenithal anchoring energies &bgr;/&agr; to give a positive energy difference &Dgr;Ws for the liquid crystal director at the surface in the C1 and C2 states. Additionally the provision of a C2 state may be enhanced by allowing the cell to cool from the isotropic phase to a temperature just below a smectic A to chiral smectic phase, then applying 50 Hz ac voltage in the range typically 0.1 to 5 volts rms. across the liquid crystal layer for about 90 seconds, then allowing the cell to cool to ambient temperature.

Abstract: A large area liquid crystal display comprises a layer of liquid crystal material between two cell walls. One cell wall has a common sheet electrode. The other cell walls comprise a plurality of addressing tiles electrically connected together. Driver circuits at the display edges apply addressing voltages. Each addressing tiles comprises a series of m data electrodes and n gate electrodes arranged to form an m×n matrix array of electrode intersections. At each intersection is a pixel patch electrode and a non linear element connected to adjacent source and gate electrodes and to the pixel electrode. The data and gate electrodes continue across the tile surface and around its edges. Adjacent tiles are electrically connected together by an anisotropic glue, or by solder bumps, or electrical bridges. The liquid crystal material may be encapsulated in a polymer matrix or be a non-encapsulated layer. Dyes may be incorporated in the liquid crystal material.

Abstract: Ferroelectric liquid crystal devices having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, and a layer of a smectic liquid crystal material enclosed between the cell walls, exhibits a minimum in its response time versus voltage curve. The crystal material has two components, A and B.

Abstract: A ferroelectric liquid crystal display comprises a layer of ferroelectric liquid crystal material contained between two cell walls, surface treated to align the material in a tilted layer. The walls carry eg row and column electrodes forming an x,y matrix of addressable elements or pixels. Multiplex addressing voltages are provided by driver circuits. An improved addressing is obtained by varying the addressing voltage applied during switching of a pixel to maximize torque applied on liquid crystal molecules. Addressing voltages are from two data waveforms and one strobe waveform; the data waveforms have more than two voltage levels, dc balance, and equivalent rms. values; the strobe waveform has two or more voltage levels (which may include a zero level). The strobe and data waveforms combine to provide a resultant voltage that form an addressing voltage at each pixel.

Abstract: Ferroelectric liquid crystal devices are described which contain liquid crystal mixtures comprising components A and B. Component A consists of one or more optically active compounds capable of imparting a spontaneous polarization to the material. Component B is selected as one or more compounds having formula (I), wherein a, b and c are independently 0, 1, 2; R.sub.1 and R.sub.2 are C.sub.1-15 straight or branched chain alkyl or alkoxy, preferably C.sub.3-12. In the above (for component B) CH=CH linking groups may be replaced by C.sub.2 H.sub.4 and CH.sub.2 O linking groups may be replaced by OCH.sub.2.

Abstract: Multiplex addressed ferroelectric liquid crystal devices containing liquid crystal mixtures composed of components A, B and C. Component A consists of one or more optically active compounds capable of imparting a spontaneous polarization to the material. Component B is a compound or compounds of the formula: ##STR1## where R.sub.1 and R.sub.2 independently represent straight or branched chain C.sub.3 -C.sub.12 alkyl or alkoxy groups, a, b and c are independently 0, 1 or 2 and the total of a+b+c is not greater than 4. Component C is selected from a range of liquid crystal components.

Abstract: A push-button switch is provided which includes a base plate having terminals extending therethrough and solderable in a p.c. board. A housing is subsequently snap-assembled with the base plate and carries a push-button member which is reciprocable when manually pushed. Cam tracks are provided in the housing and a cam follower lever is pivotally mounted on the push-button member. The lever is accessible through an aperture in the housing for engagement with either of the cam tracks. One of the cam tracks produces momentary action, while the other produces alternate action.

Abstract: A hybrid switch includes a snap-action switching portion having a butterfly-type mechanism and a solid-state switching portion formed within a single, compact housing. The solid-state switching portion is formed of an electro-electronic device consisting of a light-emitting diode and a phototransistor. Alternatively, the solid-state switching portion is formed of a bipolar transistor.

Abstract: A vane lever arm for the variable stator/vane assembly of a gas turbine engine that is fabricated from sheet metal and has a flexible thin section to allow out of plane movement and a rigid thicker end for supporting the pin attached to the synchronous ring.

Abstract: A rotary switch convertible from being operable over a smaller range of angular motion, e.g. as a two-position switch, into being operable, in either of two configurations, over larger ranges of angular motion, e.g. as a three-position switch. A rotor and a stator are assembled for relative rotation. Four lugs divide a face of the stator into four quadrants. Two pairs of lugs, each comprising a removable lug and a permanent lug, are provided on a face of the rotor. The faces are juxtaposed such that relative rotation of the rotor and the stator is limited by interference between certain of the lugs on the rotor and certain of the lugs on the stator. Before removal of either removable lug, the rotor and the stator may be assembled for a smaller range of angular motion. After removal of both removable lugs, the rotor and the stator may be assembled in either of two configurations for larger ranges of angular motion.

Abstract: An electrical switching apparatus is disclosed for making or breaking a plurality of electrical connections substantially simultaneously. The apparatus includes a planar substrate, a first set of electrical terminals arrayed on the substrate in a pattern providing mating pairs of terminals displaced by a distance, an actuator having a contact effecting surface and carrying thereon a plurality of moveable bridging contacts which are in substantial registration each with a respective mating pair of terminals. The actuator response to application of an actuating force toward the substrate to establish bridging contact by the bridging contact between each of the mating pairs of terminals substantially simultaneously. In the preferred embodiment a plurality of such switching apparati are actuated by a common actuating shaft.

Abstract: A blade vibration damper for a rotor assembly of an axial flow machine seats simultaneously on a radially inwardly facing surface of a blade platform and the radially inwardly facing surface of an adjacent element, such as the platform of a circumferentially adjacent blade. The damper has its mass center of gravity nearer one contact area than the other so as to reduce the normal load on the blade platform generated by centrifugal force. By properly locating the center of gravity of the damper, the size of the normal force can be optimized to maximize damping.

Abstract: A trailer for towing by family saloon cars and the like has a wheeled frame (12) with a towing hitch (34) at the front. The frame has a respective ramp rail (22) at each side to enable a skip (14) to be drawn onto the frame, a support wheel (25) of the skip engaging on each rail. The skip can carry heavy bulk loads such as sand or bricks in the region of a ton which normal car trailers could not support. In addition, the mounting of the skip on the trailer frame by means of support wheels enables the skip to be pivoted in situ to tip out its load. Tipping, and mounting and demounting of the skip are effected using winch (16) supported on the frame near the towing hitch. The trailer also has a pivotable ramp (50) enabling the trailer to be used to carry heavy plant such as a cement mixer or roller.

Abstract: This invention relates to insulation materials and, in particular, to thermal insulation materials having heat reflective properties.In particular insulation material according to the invention comprises a random array of elements as herein defined having at least a portion thereof deformed so as to increase the resilience of the elements and to assist in forming spaces between adjacent elements in the random array.In this specification the term element is used to include filaments of different cross-sectional shape, for example, circular, square or rectangular, strips of uniform or non-uniform width and/or thickness, flakes and platelets of regular or irregular geometric shape and of uniform or non-uniform thickness, and the like.

Abstract: Effective damping of blade vibratory energy is sought by the apparatus described herein. The concepts relate specifically to what is known as blade to blade damping as is distinguished from blade to ground damping.The dampers employed have a "T" shaped cross section geometry and are designed to extend circumferentially on an engine rotor between the platform sections of each pair of rotor blades. The dampers are of extreme light weight such that the slipload forces required to generate sliding contact between the damper and the blade platforms is low.

Abstract: Apparatus for rotating a cathode ray tube (CRT) which is operated as a graphic display through 90 degrees such that different size pages of data may be displayed while minimizing the control circuitry required. The display deflection yoke is fixedly attached to a support frame for the display. The CRT is rotatably mounted within the yoke and held by annular thrust bearing which allows the CRT to be rotated 90 degrees. A switch is actuated by the rotation of the CRT to select between sets of control resistors to control the raster scan of the CRT in accordance with its orientation.

Abstract: A cutting guide for urging work material against the rip fence of a circular saw, joiner, shaper, or the like, includes a mounting block which is clamped to the work table with the mounting block provided with two spring steel bands arranged in loops and mounted in overlapping relation to each other on the mounting block. The spring bands are angled to provide a lead-in in the direction of work feed.

Abstract: Effective damping of blade vibratory energy is sought by the apparatus described herein. The concepts relate specifically to what is known as blade to blade damping as is distinguished from blade to ground damping.The dampers employed have a "T" shaped cross section geometry and are designed to extend circumferentially on an engine rotor between the platform sections of each pair of rotor blades. The dampers are of extreme light weight such that the slipload forces required to generate sliding contact between the damper and the blade platforms is low.