Load sensing arrangement
A system to remotely report the load condition of a railroad car including a mechanism to sense the load condition in the form of a switch responsive to load condition to change the state of an electrical circuit, a controller to recognize the state of the circuit and a radio wave transmitter directed by the controller to report the condition to a remote receiver. Load is sensed by recognition of the distance between two components of the car, one which remains relatively fixed regardless of the weight of the car, the other which moves relative to the first component as the car weight changes.
1. A load sensing mechanism for a railroad car having a car truck with a bolster and side frame;
said mechanism including a sensor to sense displacement of the bolster relative to the side frame;
said sensor comprising an electrical switch assembly mounted to on of said side frame and bolster;
an actuator connected to said switch assembly biased to a neutral position and moveable in a range of positions displaced from said neutral positions;
said actuator contactable with the other of said side frame and bolster to displace said actuator from said neutral position at predetermined loads of the car;
said switch assembly having one electrical state when said actuator is in said neutral position and another electrical state when said actuator is in said range of displaced positions; and
said actuator being responsive to the weight of said car to move said switch between said neutral position and said range of displaced positions.
2. A load sensing mechanism as claimed in claim 1 wherein said actuator is spring biased to be straight in said neutral position and bent when displaced to said range of positions.
3. A load sensing mechanism as claimed in claim 1 wherein said actuator includes a fulcrum and shaft and a follower arm biased to said neutral position and pivoted to said range of displaced positions.
4. A load sensing mechanism as claimed in any one of claims 2 and 3 wherein said switch is a normally closed switch when said actuator is in said neutral position and is open when said actuator is in said range of displaced positions.
5. A system to report the load condition of a railroad car comprising:
a mechanism to sense the load condition;
an electrical circuit;
a switch in said circuit responsive to the sensed condition to switch said electrical circuit between a first state and a second state at a predetermined load condition of said car;
a controlled responsive to the state of the circuit and having an output indicative of the state of said circuit; and
a transmitter receiving said output by said controller to transmit a radio wave indicative of the load condition of the car;
wherein the mechanism to sense the load condition of the car comprises a first car element that remains relatively fixed regardless of the weight of the car and a second element that moves relative to the first car element as the weight changes; and
wherein said railroad car comprises a car truck bolster and side frame;
said load sensing mechanism includes a sensor to sense displacement of the bolster relative to the side frame;
said sensor comprising an electrical switch assembly mounted to one of said side frame and bolster;
said actuator connected to said switch assembly biased to a neutral position and moveable in a range of positions displaced from said neutral positions;
said actuator contactable with the other of said side frame and bolster to displace said actuator from said neutral position at predetermined loads of the car;
said switch assembly having one electrical state when said actuator is in said neutral position and another electrical state when said actuator is in said range of displaced positions; and
said actuator being responsive to the weight of said car to move said switch between said neutral position and said range of displaced positions.
6. A system as claimed in claim 5 wherein said actuator is spring biased to be straight in said neutral position and bent when displaced to said range of positions.
7. A system as claimed in claim 5 wherein said actuator includes a fulcrum and shaft and a follower arm biased to said neutral position and pivotal to said range of displaced positions.