GB1301359A - - Google Patents

Abstract

1301359 Measuring parameters of wheels electrically K FRITZE 15 Sept 1970 [15 Sept 1969] 44061/70 Heading G1N [Also in Division H3] The physical parameters of a wheel on a vehicle are measured electrically and transmitted by reactive coupling elements to the driving cab, the rotating coupling element on the wheel being embedded in a ring of insulating material on the rim of the wheel. As shown, Fig.1, a signal from from an oscillator 4 on a vehicle 1 is coupled via elements 8a, 8b to a wheel 3, the returned signal being fed back at 10 to the oscillator to modify its output, which is amplified at 11 and indicated at 12 in the cab 2. The signal representing the measured parameter may operate an audible or visible alarm, or control the brightness of a panel light. Element 8a, 8b are preferably inductive units forming part of a local resonant circuit, wherein the capacitive component may have a di-electric which is sensitive to temperature or pressure, or the inductor may have a ferrite core sensitive to temperature or pressure, or the Q value of the resonant circuit may be varied by a temperature or pressure sensitive resistor or a temperature/pressure switch may be incorporated in the circuit to change its characteristics at preset values of temperature and/or pressure. The pick-up unit 8b may be provided with a core to produce directional characteristics. The oscillator may be coupled to other transducers, with each pick-up coil 8b feeding its own indicator 12, or a common indicator through electronic switching elements operated manually or automatically. The coupling unit on the wheel comprises an element 60 Fig.17 embedded in e.g. a rubber ring 57 having a flange 59 to enable the ring to be gripped between a tyre 58 and the inner rim 56 of the wheel. The oscillator 4 Fig.4 may have capacity diodes 16 associated with its tuning circuit, which are fed with a saw tooth voltage at 17 whereby the output frequency is periodically swept through a frequency range. Each transducer at each wheel forms part of a resonant circuit tuned to a preset frequency, whereby the oscillator output amplitude at that frequency represents the value of the parameter measured by that transducer. The signal representing the measured parameter may control the sweep frequency, to prolong the duration of an alarm value.