High voltage operating rod sensor and method of making the same
Methods and system for making and using vacuum switching devices are disclosed. A vacuum switching device has an operating rod for actuating a movable electrical contact within the device. The operating rod may be a hollow epoxy glass tube with an electrical sensor disposed within it, and there may be an elastomeric polymer filling compound disposed within the tube and encasing the sensor. The operating rod may be attached to the movable electrical contact on one end by a steel end-fitting that has been press-fit into the tube and secured with at least one cross pin. In this way, a very secure electromechanical connection may be made between the operating rod and the rest of the vacuum switching device, and the sensor is protected from shock associated with the operation of the device. Moreover, the vacuum switching device is compact and easy to construct.
1. A vacuum switching device, the device comprising:
a vacuum assembly having switching contacts disposed therein, one of the switching contacts being a movable switching contact that is movable along an axis;
a tube disposed along the axis and operable to actuate movement of the movable switching contact along the axis;
a sensor disposed within the tube; and
an elastic compound that encapsulates the sensor, is provided within the tube, and is made from a material different from a material of the tube;
wherein the tube is encased in a ribbed silicone sleeve.
2. The device of claim 1 further comprising:
a fitting attached to the tube and to the movable switching contact; and
a pin socket assembly connected to the fitting and to the sensor.
3. The device of claim 1 wherein the sensor comprises a resistive element.
4. The device of claim 1 wherein the tube is made of radially-wound epoxy glass.
5. The device of claim 2 further comprising a cross pin that is inserted through the tube and the fitting to hold the fitting in place.
6. The device of claim 5 further comprising a conductive guard sleeve electrically connected to the fitting by the cross pin.
7. The device of claim 6 wherein the fitting is grounded, whereby the conductive guard sleeve is also grounded.
8. The device of claim 5 wherein the sensor comprises a voltage-sensing resistor that is electrically connected to the fitting via a the pin socket assembly.
9. The device of claim 1 wherein the vacuum switching device includes a vacuum fault interrupter.
10. A vacuum switching device including an operating rod, the operating rod comprising:
a radially-wound, epoxy glass tube;
a sensor disposed within the tube; and
an elastomeric polymer compound within the tube and encasing the sensor wherein the elastomeric polymer compound is made from a material different from the radially-wound, epoxy glass material of the tube; and
a ribbed silicone sleeve that encases the tube.
11. The device of claim 10 wherein the operating rod comprises:
a silicone sleeve encasing a first portion of the operating rod; and
a grounded guard sleeve around a second portion of the operating rod.
12. The device of claim 1 wherein the tube is an insulating tube.