Abstract: A proximity sensor has a metal case with a sensing coil at one end and a coaxial cable extending out the other end for placement in proximity to rotating machinery to sense imbalances by position change of, for example, a shaft. The sensor includes a cylinder integrally molded with a plastic bobbin which carries the coil on its end. This unitary assembly then has inserted in it the coaxial cable and the typically wire braided outer conductor is soldered onto the cylinder to provide a permanent interlock resistance against axial and torsional forces. A plastic insulating cap is placed over the entire assembly including the sensing coil and epoxied thereto. A sleeve over the junction between the cable and cylinder prevents unwanted epoxy from filling the coaxial cable. Finally, this permanent affixing of the cap allows the metal casing normally having a nut and thread to be crimped onto a notch in the cap. Moisture proofing is also provided by injection of silicone rubber in the cavity of the bobbin.

Abstract: A proximity sensor has a metal case with a sensing coil at one end and a coaxial cable extending out the other end for placement in proximity to rotating machinery to sense imbalances by position change of, for example, a shaft. The sensor includes a cylinder integrally molded with a plastic bobbin which carries the coil on its end. This unitary assembly then has inserted in it the coaxial cable and the typically wire braided outer conductor is soldered onto the cylinder to provide a permanent interlock resistance against axial and torsional forces. A plastic insulating cap is placed over the entire assembly including the sensing coil and epoxied thereto. A sleeve over the junction between the cable and cylinder prevents unwanted epoxy from filling the coaxial cable. Finally, this permanent affixing of the cap allows the metal casing normally having a nut and thread to be crimped onto a notch in the cap. Moisture proofing is also provided by injection of silicone rubber in the cavity of the bobbin.