Voltage sensing hand tool
View Patent ↗A hand tool which provides an alarm signal to a user as the tool approaches a live electrical wire is disclosed. The hand tool comprises a tool head and coupled to a handle. A non-contact voltage sensing circuit is provided in the handle of the tool. As the tool approaches a live electrical wire, the non-contact voltage sensing circuit detects the voltage across the air gap between the tool head and the electrical wire, triggering an alarm circuit. The alarm circuit provides a visual or audio signal to the user.
1. A hand tool, comprising:
a tool head; and
a handle, wherein the handle is coupled to the tool head to provide a user interface for the tool head and wherein the handle includes a non-contact voltage sensing circuit including an antenna provided at the end of the handle opposite the tool head, the non-contact voltage sensing circuit including at least one indicator providing an alarm signal indicating that the hand tool is in proximity to a live electrical wire.
2. The hand tool as defined in claim 1 , wherein the tool head is at least one of a wire cutter, a wire stripper, a screw driver, a wrench, and a pliers.
3. The hand tool as defined in claim 1 , wherein the non-contact voltage sensing circuit includes a comparator for comparing a voltage sensed at the conductive tool head to a threshold voltage level and an alarm circuit for generating the alarm signal when the threshold voltage level is exceeded.
4. The hand tool as defined in claim 1 , wherein the alarm circuit includes at least one of a visual and an audio indicator device for generating the alarm signal.
5. The hand tool as defined in claim 1 , further comprising an actuator for selectively activating the non-contact voltage sensing circuit.
6. The hand tool as defined in claim 1 , wherein the non-contact voltage alert circuit comprises an oscillator for driving the audible alert indicator in an audio frequency range.
7. The hand tool as defined in claim 1 , wherein the non-contact voltage sensing circuit is electrically insulated from the tool head.
8. A hand tool, comprising:
a tool head that is at least one of a wire cutter, a wire stripper, a screw driver, a wrench, and a pliers;
a handle operatively connected to the tool head;
a non-contact voltage sensing circuit housed in the handle, the non-contact voltage sensing circuit including an antenna encapsulated in the handle and an alarm circuit for generating a human perceptible alarm signal when a threshold voltage level indicating that the hand tool is in proximity to a live electrical wire is detected.
9. The hand tool as defined in claim 8 , wherein at least a portion of the handle includes a translucent material and the human perceptible alarm circuit is a light indicator provided adjacent the translucent portion of the handle.
10. The hand tool as defined in claim 8 , wherein at least a portion of the handle comprises a rubberized layer.
11. The hand tool as defined in claim 8 , wherein the antenna is electrically connected to the non-contact voltage sensing circuit inside of the handle.
12. The hand tool as defined in claim 8 , wherein the alarm circuit further activates a sound transducer.
13. The hand tool as defined in claim 8 , wherein the tool head is a wire stripper comprising a first and a second non-conductive blade.
14. The hand tool as defined in claim 8 , wherein the tool head is electrically insulated from the non-contact voltage sensing circuit.
15. A hand tool comprising:
a) a tool head that is at least one of a wire cutter, a wire stripper, a screw driver, a wrench and a pliers to work a work piece;
b) a handle connected to the tool head so as to operate the tool head to work the work piece;
c) a non-contact voltage sensing circuit provided in the handle and including an antenna provided adjacent an end of the handle opposite the tool head for detecting an electrical field; and
d) an alarm device, the alarm device being activated by the non-contact voltage sensing circuit to provide a signal to indicate that the hand tool is in an electrical field at an elevated voltage when the antenna detects an electrical field having a voltage level above a predetermined threshold.
16. The hand tool as defined in claim 15 , wherein the alarm device comprises a visible alert indicator.
17. The hand tool as defined in claim 15 , wherein the alarm device comprises a light emitting diode.
18. The hand tool as defined in claim 15 , wherein the handle comprises a translucent portion, and the visible alert indicator is positioned adjacent the translucent portion of the handle.
19. The hand tool as defined in claim 15 , wherein the handle further comprises a thermoplastic rubber over mold.
20. The hand tool as defined in claim 15 , wherein the tool head is a wire stripper.
21. The hand tool as defined in claim 15 , wherein the handle is formed to include a cavity for receiving the non-contact voltage sensing circuit.
22. The hand tool as defined in claim 15 , wherein the tool head is constructed of a non-conductive material.
23. The hand tool as defined in claim 15 , wherein the non-contact voltage sensing circuit is electrically insulated from the tool head.