Elastic strip with contacts for detecting the transit of motor vehicles with a protection against wear

Claim 1

A strip for detecting the passage of motor vehicles comprising in combination: a deformable body made of an elastomeric material defining an elongated cavity with two load directing channels extending along either side of the central portion of said cavity so as to define upper and lower central projections therebetween, the upper central wall of said cavity being substantially planar and having secured thereto a first switch member, the lower wall of said central portion of said cavity having secured thereto a second switch member, a semi-circular upper portion surmounting said deformable body for contacting the wheels of motor vehicles as they pass thereover, said deformable body having sidewalls extending a substantial distance on either side of the base of said semi-circular portion and a substantial distance about said load-directing channels, the base of said semi-circular portion being larger than the upper planar wall of said cavity and in spaced parallel relation thereto, so that said base and said upper wall define generally a trapezoid, the ends of said base of said semi-circular portion extending laterally further than the ends of said upper wall of said central portion of said cavity so that a lower, shorter side of said trapezoid is disposed between said channels, whereby upon application of a load onto said strip by a passing motor vehicle said sidewalls, channels and cavity cooperate so that said body deforms such that the respective sides of said trapezoid remain substantially parallel to their orientation in the relaxed state of said strip, thereby minimizing the shear stresses applied to said strip when it is compressed to bring into contact said switch members.