Abstract: According to the present invention, there is provided a secondary engine cover formed from a polymeric material comprising a wear indicator, wherein the wear indicator comprises a region of reduced thickness of polymeric material and wherein the region of reduced thickness comprises a blind hole.

Abstract: A method for determining the position of a liquid interface between a lower tray and an upper tray in a process apparatus such as a distillation column, using gamma scanning and comparing the maximum count rate of gamma photons measured between two trays with the count rate attributed to scanning through the apparatus filled with vapor. The method enables the operating parameters of the apparatus to be optimized and provides a manner of calculating the % flood of an individual tray.

Abstract: According to the present invention, there is provided a secondary engine cover formed from a polymeric material comprising a wear indicator. It is recommended and encouraged that teams, and track day public, replace the secondary engine cover after each and every crash, to ensure the best rider safety possible. However, because of some products inherent high performance and durability, this good practice has not always been followed. Some deem that it is not always necessary to change, a practice that it is not wished to encourage and which should be changed. In this invention, wear indicators are created in one alternative in the form of round holes appearing in on the top surface of the secondary engine cover when crucial areas of material of the secondary engine cover have been worn down.

Abstract: An acoustic device intended to operate pistonically and in bending comprising a panel-form acoustic radiator, a magnetic drive system including a voice coil on a tubular bobbin, the bobbin being directly coupled to the radiator to drive the radiator directly; and a coupling device connected to the bobbin, and to the radiator at a position at or near to the first nodal line of bending resonance of the radiator. A method of improving the on-axis response of a loudspeaker having a panel-form radiator and intended to operate both pistonically and in bending, comprising driving the radiator by a directly connected tubular bobbin, and substantially suppressing the lowest natural frequency of the radiator by providing a coupler connected from the bobbin to the radiator at or near to its first nodal line.

Abstract: A method for determining the position of a liquid interface between a lower tray and an upper tray in a process apparatus such as a distillation column, using gamma scanning and comparing the maximum count rate of gamma photons measured between two trays with the count rate attributed to scanning through the apparatus filled with vapour. The method enables the operating parameters of the apparatus to be optimized and provides a manner of calculating the % flood of an individual tray.

Abstract: The invention relates to an acoustic device and a method of making the same. The acoustic device comprises a diaphragm having an area and having an operating frequency range comprising a part in which the diaphragm moves in whole body mode and a part which includes at least the first bending mode. The acoustic device also comprises a moving coil transducer adapted to move the diaphragm in translation and having a voice coil coupled to the diaphragm and a magnet system and adapted to exchange energy with the diaphragm. The acoustic device also comprises at least one mechanical impedance means coupled to or integral with the diaphragm. The positioning and mass of the transducer voice coil and of the at least one mechanical impedance means is such that the net modal transverse velocity over the area of the diaphragm tends to zero. The transducer comprises a moving coil assembly having a coil former on which are mounted a plurality of voice coils in an axially-spaced array.

Abstract: An acoustic device and method of making said acoustic device. The acoustic device comprises a diaphragm having resonant bending wave modes in the operating frequency range, and a plurality of electromechanical transducers coupled to the diaphragm. The positioning and mechanical impedance of the transducers are such that at least a selected number of the resonant bending wave modes are balanced so that the net transverse modal velocity over the area of the diaphragm tends to zero with the balancing of the resonant bending wave modes being achieved substantially by the positioning and mechanical impedance of the transducers. The parameters of the diaphragm may be such that there are a plurality of nodal grouped locations at or around which the nodal lines of a selected number of resonant modes are clustered. Each transducer may be mounted at one of the plurality of nodal grouped locations.

Abstract: A composition for use in injection molded protective articles including: a) a polymeric material; and b) long glass fibres. Preferred additives including: a) a flow modifier; b) an impact modifier; and c) an impact stabiliser. A protective article formed from the composition.

Abstract: An acoustic device comprising a diaphragm (10) having an area and having an operating frequency range and the diaphragm (10) being such that it has resonant modes in the operating frequency range, an electro-mechanical transducer having a drive part coupled to the diaphragm (10) and adapted to exchange energy with the diaphragm, and at least one mechanical impedance means (20,22,24) coupled to or integral with the diaphragm, the positioning and mass of the drive part (26) of the transducer and of the at least one mechanical impedance means (20,22,24) being such that the net transverse modal velocity over the area of the diaphragm (10) tends to zero.

Abstract: An acoustic device intended to operate pistonically and in bending comprising a panel-form acoustic radiator, a magnetic drive system including a voice coil on a tubular bobbin, the bobbin being directly coupled to the radiator to drive the radiator directly; and a coupling device connected to the bobbin, and to the radiator at a position at or near to the first nodal line of bending resonance of the radiator. A method of improving the on-axis response of a loudspeaker having a panel-form radiator and intended to operate both pistonically and in bending, comprising driving the radiator by a directly connected tubular bobbin, and substantially suppressing the lowest natural frequency of the radiator by providing a coupler connected from the bobbin to the radiator at or near to its first nodal line.

Abstract: An acoustic device comprising a diaphragm (10) having an area and having an operating frequency range and the diaphragm (10) being such that it has resonant modes in the operating frequency range, an electromechanical transducer having a drive part coupled to the diaphragm (10) and adapted to exchange energy with the diaphragm, and at least one mechanical impedance means (20,22,24) coupled to or integral with the diaphragm, the positioning and mass of the drive part (26) of the transducer and of the at least one mechanical impedance means (20,22,24) being such that the net transverse modal velocity over the area of the diaphragm (10) tends to zero.

Abstract: A transducer (14) for producing a force which excites an acoustic radiator, e.g. a panel (12) to produce an acoustic output. The transducer (14) has an intended operative frequency range and comprises a resonant element which has a distribution of modes and which is modal in the operative frequency range. Parameters of the transducer (14) may be adjusted to improve the modality of the resonant element. A loudspeaker (10) or a microphone may incorporate the transducer.

Abstract: An electromechanical force transducer having an intended operative frequency range comprises a resonant element (10) having a periphery and having a frequency distribution of modes in the operative frequency range, characterized by support means (16) coupled to the periphery of the resonant element, the support means (16) having a substantially restraining nature in relation to bending wave vibration of the resonant element (10). The transducers may be mounted to an acoustic radiator (12) in a loudspeaker via coupling means (14) to excite the acoustic radiator to produce an acoustic output.

Abstract: An acoustic device and method of making said acoustic device. The acoustic device comprises a diaphragm having resonant bending wave modes in the operating frequency range, and a plurality of electromechanical transducers coupled to the diaphragm. The positioning and mechanical impedance of the transducers are such that at least a selected number of the resonant bending wave modes are balanced so that the net transverse modal velocity over the area of the diaphragm tends to zero with the balancing of the resonant bending wave modes being achieved substantially by the positioning and mechanical impedance of the transducers. The parameters of the diaphragm may be such that there are a plurality of nodal grouped locations at or around which the nodal lines of a selected number of resonant modes are clustered. Each transducer may be mounted at one of the plurality of nodal grouped locations.

Abstract: A bending wave loudspeaker having an operating frequency range and a coincidence frequency which is above the operating frequency range, comprising a resonant panel having two generally orthogonal axes, vibration exciting means coupled to the panel to excite the panel into resonance along the one axis of the panel, and means restraining or preventing resonance along the other axis of the panel whereby the panel radiates an acoustic output which is of wide directivity along the one axis and of narrow directivity along the other axis of the panel.

Abstract: An acoustic device comprising a diaphragm (10) having an area and having an operating frequency range and the diaphragm (10) being such that it has resonant modes in the operating frequency range, an electromechanical transducer having a drive part coupled to the diaphragm (10) and adapted to exchange energy with the diaphragm, and at least one mechanical impedance means (20,22,24) coupled to or integral with the diaphragm, the positioning and mass of the drive part (26) of the transducer and of the at least one mechanical impedance means (20,22,24) being such that the net transverse modal velocity over the area of the diaphragm (10) tends to zero.

Abstract: A transducer (14) for producing a force which excites an acoustic radiator, e.g. a panel (12) to produce an acoustic output. The transducer (14) has an intended operative frequency range and comprises a resonant element which has a distribution of modes and which is modal in the operative frequency range. Parameters of the transducer (14) may be adjusted to improve the modality of the resonant element. A loudspeaker (10) or a microphone may incorporate the transducer.

Abstract: A magnet assembly having inner and outer yokes of magnetic flux conductive material which together define an annular air gap and a radially oriented magnet sandwiched between the inner and outer yokes such that a first face of a first magnetic polarity contacts the inner yoke and a second face of a second opposite magnetic polarity contacts the outer yoke, characterised by an axially oriented magnet forming part of the magnet assembly, and wherein the radially oriented magnet is annular and has opposed axial ends, and the inner and outer yokes are annular and together enclose one axial end of radially oriented magnet to define the air gap, and wherein the axially oriented magnet is disposed adjacent to the other axial end of the radially oriented magnet, whereby the inner and outer yokes and the axially oriented magnet together reduce flux leakage from the magnet assembly.

Abstract: A bending wave loudspeaker includes a transparent acoustic radiator capable of supporting bending wave vibration and an electromechanical force transducer mounted to the acoustic radiator to excite bending waves in the acoustic radiator to produce an acoustic output. The transducer has an intended operative frequency range and includes a resonant element having a frequency distribution of modes in the operative frequency range and a coupler for mounting the transducer to the acoustic radiator. The loudspeaker may be incorporated in a telephone handset or a visual display unit.

Abstract: A transducer (14) for producing a force which excites an acoustic radiator, e.g. a panel (12) to produce an acoustic output. The transducer (14) has an intended operative frequency range and comprises a resonant element which has a distribution of modes and which is modal in the operative frequency range. Parameters of the transducer (14) may be adjusted to improve the modality of the resonant element. A loudspeaker (10) or a microphone may incorporate the transducer.