Smiths Industries Public Limited Company

Smiths Industries Plc

Geoffrey Beardmore

Hugh N Evans

Antony P Neville

An aircraft has several ultrasonic phased arrays acoustically bonded to parts of its structure to be monitored. The arrays are energized to produce an ultrasonic beam that scans the structure in two planes. A monitor receives the output from the arrays produced by reflection of energy from discontinuities within the structure. When there is a change in these outputs, the monitor signals a pilot display unit and a flight control system such that the aircraft flight envelope can be restricted to minimize damage.

Monitoring

Current sensor assemblies

Tunnel pick-off vibrating rate sensor

A gas discharge lamp has a tubular envelope containing tubular electrodes at opposite ends. An annular support member of a compressible ceramic fiber is supported in a groove around each electrode and is compressed against the inside surface of the envelope. Movement of the electrodes relative to the envelope is damped by the support member.

Electrode structures with electrically insulative compressable annular

A display has a matrix array of cells formed in a silicon plate and each containing a tungsten strip filament. The cells are filled with a halogen gas and are sealed by a double-glazed window with an infra-red reflecting filter to reflect heat back into the cell while allowing the transmission of visible radiation. The rear of the plate is treated to make it microporous and reduce its thermal conductivity.

Incandescent light-emitting assemblies

The inner unit of a gyroscope is of circular shape and is formed with an inclined outer edge at one end. The inner unit slides within an outer casing having a transverse end face at one end. An annular recess of triangular section is thereby defined between the inner unit and casing which receives a ring of resilient material. During assembly the inner unit is urged against the end of the casing, to compress the ring within the recess, by reducing pressure within the casing. The inner unit is held in position, with the ring compressed, by soldering an end plate to the casing. The pressure within the casing can then be returned to normal.

Arrangements and methods of mounting a unit in a casing

Gyroscope apparatus includes a tubular rotor that is supported at opposite ends by bearings, such as a gas-lubricated bearing, for rotation about its axis. A gimbal ring encircles the rotor and is resiliently supported with the rotor, for angular displacement about an axis at right angles to the rotor axis, by a pair of flexure pivots located intermediate the ends of the rotor. An inertia ring is mounted concentrically with the gimbal ring by another pair of flexure pivots for angular displacement about an axis at right angles to the rotor axis and the axis of displacement of the gimbal ring. The major part of each flexure pivot is contained within the radial thickness of the gimbal ring. Displacement of the inertia ring is sensed by pick-offs the outputs of which are used to control the restoring torque applied by torquers located outwardly of the pick-offs.

Dynamically tuned gyroscopes

The spiral grooving of a thrust-plate of an aerodynamic gas-lubricated bearing is formed by ionic bombardment of a flat face of a machined blank. The face is masked to leave exposed only those areas where material is to be removed. Grooving on a cylindrical surface of a spindle is similarly formed, the cylindrical blank being rotated to present the unmasked areas successively and repeatedly for bombardment.

Gas-lubricated bearings

A flexure-pivot for providing resilient restraint that opposes relative angular displacement between two members involves two flat springs, that are held at one end between pairs of pins carried by one member and at the other end between pairs of pins carried by the other member, the flat springs each having two parallel rib portions that are linked at one end and are interlaced with one another. In one form of flexure-pivot the unlinked end of both the rib portions of each spring is secured between a pair of pins carried by one member and the linked end of both the rib portions of each spring is secured between a pair of pins carried by the other member. In another form of flexure-pivot the pairs of pins carried by one member are axially aligned with the pairs of pins carried by the other member, when there is no relative displacement between the members, and the unlinked end of one of the rib portions is secured to one of the pairs of pins carried by one member and the unlinked end of the other one of the rib portions is secured to the axially aligned pair of pins carried by the other member, so that there is a resilient interconnection between the axially aligned pairs of pins. In both forms of flexure-pivot, further pins are mounted with one or other of the members to limit relative angular displacement between the two members by engagement with pairs of pins mounted on an opposite member. Manufacture of both forms of flexure-pivot is initially the same and is carried out by inserting the ends of four pairs of pins in holes in one member, securing each end of the two flat springs between opposite pairs of pins, inserting the other ends of the four pairs of pins in holes in the other member, and brazing the assembly formed to secure the springs to the pins and the pins to the members. One form of flexure-pivot is subsequently formed by cutting two adjacent pairs of pins close to one member and the other two adjacent pairs of pins close to the other member. The other form of flexure-pivot however is formed by cutting through two adjacent pairs of pins at points between the rib portions and cutting through the other two adjacent pairs of pins at one point close to one member and at another point close to the other member.

Growing community of inventors

Cheltenham, United Kingdom

Geoffrey Beardmore