Patent ID: 7498530

Claim:
A sensor assembly for use in a hatch position notification system on a tank car, the sensor assembly comprising: a hollow rod sleeve having a top end, a bottom end, and a side, wherein the side of the hollow rod sleeve has a hole through which an actuating member can pass; an actuator rod within the hollow rod sleeve, the actuator rod having a top end, a bottom end, and an engagement notch, wherein the engagement notch is located proximate to the hole in the hollow rod sleeve; a spring within the hollow rod sleeve, the spring having a top end and a bottom end, wherein the bottom end of the spring is adjacent to a fixed surface, and the top end of the spring is adjacent to the bottom end of the actuator rod; a 2-position electrical switch, the switch having an actuating member substantially perpendicular to the actuator rod, wherein the actuating member extends from the electrical switch through the hole in the hollow rod sleeve and wherein the actuating member has a curved end that contacts the actuator rod, wherein, when a hatch is in the open position, the spring is extended and the actuator rod is positioned such that the curved end of the actuating member of the 2-position electrical switch makes contact with the actuator rod at a point other than the engagement notch, which places the 2-position electrical switch in a first position indicating that the hatch is opened; and wherein, when the hatch is in a closed position, the hatch causes the actuator rod to move and compress the spring, which causes the actuator rod to be positioned such that the curved end of the actuating member of the 2-position electrical switch makes contact with actuator rod at the engagement notch, which places the 2-position electrical switch in a second position indicating that the hatch is closed.