초록 ▼

The displacement sensor of this invention comprises a tube combined with a sonic transmitter and receiver. The tube acts as a waveguide for the sonic waves and a processor determines whether the tube has changed in length or has been constricted which, in either case, changes the pattern of sonic wa

The displacement sensor of this invention comprises a tube combined with a sonic transmitter and receiver. The tube acts as a waveguide for the sonic waves and a processor determines whether the tube has changed in length or has been constricted which, in either case, changes the pattern of sonic waves traveling from the transmitter to the receiver. In some applications, the transmitter and receiver are at different ends of the tube. In these cases, the attenuation in sound energy reaching the receiver, caused by the tube being squeezed at at least one point, is measured and the amount of cross action area reduction is determined. In other applications, the transmitter and receiver are at the same end of the tube and, in some of these cases, the transmitter and receiver are the same transducer. When the transmitter and receiver are at the same end of the tube, the receiver receives sonic waves reflected from a constriction in the tube and the time between transmission and reception of the waves permits the processor to determine the location along the tube of the constriction. The measuring device of this invention can also be used to measure the change in length of the tube or effective length, such as when the tube is partially filled with a liquid.

대표청구항 ▼

A device for determining the displacement of an object relative to a stationery support comprising: a) a compliant tube having two ends and a bore therein, said bore of said tube having a length, said tube being in contact with said object and positioned so that the displacement of said object again

A device for determining the displacement of an object relative to a stationery support comprising: a) a compliant tube having two ends and a bore therein, said bore of said tube having a length, said tube being in contact with said object and positioned so that the displacement of said object against said tube relative to said support causes said tube to deform to thereby decrease the cross section area at some location along said length of said bore of said tube; b) a sonic transmitter attached to one end of said tube; c) a sonic receiver attached to one end of said tube; and d) processor means connected to said sonic transmitter and said sonic receiver; wherein said processor means causes said sonic transmitter to send sonic waves into said tube where said sonic waves are modified by the amount of change of said tube bore cross section area at said location along said length of said bore, after which, said modified waves are received by said receiver which produces a signal which is processed by said processor means to determine the amount of constriction of said tube caused by said object.