Tubular sonic displacement sensor

A device for detecting an obstacle in the path of a moving object against a stationery support comprising:

• a) a compliant tube having two ends and a bore therein, said bore having a length, said tube positioned against said support to contact said obstacle when said obstacle is in the path of said moving object so that said obstacle contacts and causes a deformation of said tube decreasing 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, said sonic transmitter producing sonic waves within said tube;
• c) a sonic receiver attached to one end of said tube, said sonic receiver receiving said sonic waves produced by said transmitter and producing an electric signal representative of said received sonic waves;
• and
• d) detection means electrically connected to said sonic receiver, said detection means providing an output signal when said electric signal deviates by a predetermined amount from a signal characteristic of when no obstacle is in contact with said tube;
• wherein said sonic transmitter sends sonic waves into said tube where said sonic waves are modified by the change of said tube bore cross section area, after which, said modified waves are received by said receiver which produces an electric signal representative of said modified waves, and said electric signal is fed into said detector which determines whether an obstruction is present and if so provides said output signal.

A device for determining the displacement of an object relative to a stationery support comprising:

• a) a tube having two ends and a bore therein, said tube constructed of elastomeric and reinforcing materials permitting axial stretching of said tube but resisting radial deformation, said tube in contact with said object and having said two ends each connected to a point of said support and positioned to elongate in response to the normal displacement of said object against said tube;
• b) a sonic transmitter attached to one end of said tube, said sonic transmitter producing sonic waves within said tube in response to an electric signal;
• c) a sonic receiver attached to one end of said tube, said sonic receiver receiving said sonic waves produced by said transmitter and producing an electric signal representative of said received sonic waves;
• and,
• d) processor means electrically connected to said sonic transmitter and said sonic receiver,
• wherein, said processor means produces an electric signal which is fed into said sonic transmitter causing it to send sonic waves into said tube to said receiver, said receiver receives said sonic waves and produces said representative electric signal which is processed by said processor means to determine the amount of elongation of said tube caused by said object based on the time it takes for said waves to travel from said transmitter to said receiver.

A device for determining the crush of a vehicle experiencing a crash comprising:

• a) a compliant tube having two ends and a bore therein, said tube positioned on said vehicle so that the crush of a portion of said vehicle contacts and causes said tube to deform thereby decreasing the cross sectional area of said bore at some location along said length of said bore of said tube;
• b) a sonic transmitter attached to one end of said tube, said sonic transmitter producing sonic waves within said tube;
• c) a sonic receiver attached to one end of said tube, said sonic receiver receiving sonic waves produced by said transmitter and producing an electric signal representative of said received sonic waves;
• and
• d) detection means electrically connected to said sonic receiver, said detection means providing an output signal when said received signal deviates from a normal signal characteristic of no tube deformation by a predetermined amount, said output signal indicating that said crush of said vehicle has occurred;
• wherein, said sonic transmitter sends said sonic waves into said tube where said sonic waves are modified by the change of said tube bore cross sectional area caused by a crushing of a portion of a vehicle which deforms and contacts said tube, after which, said modified waves are received by said receiver which produces said representative electrical signal which is fed into said detector which determines whether said crush has occurred and if so provides said output signal.