Conductive boot for power tool protection
Apparatus for high voltage power line maintenance and repair. In some embodiments, a power tool has a housing which encloses an electrical load and a control electronics circuit using a first shield as a layer of conductive material which is open at a battery pack receiving slot of the housing configured to receive a removable battery pack. A removable boot surrounds the removeable battery pack and has a second shield as a layer of conductive material which combines with the first shield to form a combined shield that nominally encloses the power tool and the boot. An insulative hot stick supports the power tool at a distal end and a user interface at a proximal end. The user interface includes a communication circuit that communicates with the control electronics circuit via a non-conductive communication link that extends along the hot stick to selectively activate the electrical load.
1. A power tool assembly comprising:
a power tool comprising a housing which encloses at least an electrical load and a control electronics circuit to activate the electrical load, the housing comprising a first shield as a continuous layer of conductive material that nominally encloses the electrical load and the control electronics circuit, the first shield open at a battery pack receiving slot of the housing;
a removable battery pack mateable with the battery pack receiving slot of the housing to supply electrical power for use by the electrical load and the control electronics circuit;
a removable boot adapted to surround the removeable battery pack upon engagement with the housing, the boot comprising a second shield as a continuous layer of conductive material that nominally encloses the removeable battery pack and contactingly engages the first shield to form a combined shield that nominally encloses the electrical load, the control electronics circuit and the battery pack;
an insulative hot stick having opposing proximal and distal ends, the power tool supported by the distal end; and
a user interface supported by the proximal end of the insulative hot stick comprising a communication circuit that communicates with the control electronics circuit via a communication link to selectively activate the electrical load, the communication link comprising at least one non-conductive fiber optic cable that extends along a length of the insulative hot stick between the proximal and distal ends.
2. The power tool assembly of claim 1 , wherein the boot further comprises at least one locking feature that engages a corresponding feature of the housing to mechanically secure the boot to the housing to retain the boot in said engagement with the housing.
3. The power tool assembly of claim 1 , wherein the electrical load comprises an electric motor.
4. The power tool assembly of claim 1 , wherein the housing further comprises a continuous layer of electrically insulative material affixed to an exterior surface of the layer of conductive material forming the first shield, and the boot further comprises a continuous layer of electrically insulative material affixed to an exterior surface of the layer of conductive material forming the second shield.
5. The power tool assembly of claim 1 , further comprising a suppression circuit disposed between the first and second shields.
6. The power tool assembly of claim 1 , further comprising an interlock mechanism that prevents activation of the electrical load by the control electronics circuit responsive to absence of the boot.
7. The power tool assembly of claim 1 , wherein the combined shield forms a Faraday shield configured to protect the electrical load, the control electronics circuit and the battery pack from a coronal discharge from an adjacent high voltage power line carrying an alternating current (AC) voltage in a distribution range of from about 480 volts (V) to about 50,000V nominal phase to phase.
8. The power tool assembly of claim 1 , wherein the combined shield forms a Faraday shield configured to protect the electrical load, the control electronics circuit and the battery pack from a coronal discharge from an adjacent high voltage power line carrying an alternating current (AC) voltage in a transmission range of from about 50,000 volts (V) to about 1,000,000V nominal phase to phase.
9. The power tool assembly of claim 1 , wherein the at least one fiber optic cable extends along an interior of the insulative hot stick from the proximal end to the distal end.
10. A power tool assembly adapted for use adjacent a high voltage power line, the power tool assembly comprising:
an insulative hot stick comprising opposing proximal and distal ends;
a power tool supported by the distal end and comprising a housing which encloses at least an electrical load and a control electronics circuit to activate the electrical load responsive to the user interface, the housing comprising a first shield as a continuous layer of conductive material that nominally encloses the electrical load and the control electronics circuit, the first shield open at a battery pack receiving slot of the housing;
a removeable battery pack mateable with the battery pack receiving slot of the housing to supply electrical power for use by the electrical load and the control electronics circuit;
a removable protective boot adapted to surround the removeable battery pack upon engagement with the housing, the boot comprising a second shield as a continuous layer of conductive material that nominally encloses the removeable battery pack and overlaps a first portion of the first shield to form a combined shield that nominally encloses the electrical load, the control electronics circuit and the battery pack; and
a user interface supported by the proximal end of the insulative hot stick configured to enable a user to activate the power tool assembly via a non-conductive communication link that extends along an overall length of the insulative hot stick, the communication link establishing communication between a user interface communication circuit of the user interface and the control electronics circuit.
11. The power tool assembly of claim 10 , wherein the communication link comprises a fiber optic cable.
12. The power tool assembly of claim 11 , wherein the fiber optic cable extends along an interior of the insulative hot stick from the proximal end to the distal end.
13. The power tool assembly of claim 10 , wherein the communication link utilizes hydraulic fluid.
14. The power tool assembly of claim 10 , wherein the combined shield forms a Faraday shield configured to protect the electrical load, the control electronics circuit and the battery pack from a coronal discharge from an adjacent high voltage power line carrying an alternating current (AC) voltage of at least about 480 volts (V) nominal phase to phase.
15. The power tool assembly of claim 10 , wherein the boot further comprises a locking feature that engages a corresponding feature of the housing to mechanically secure the boot to the housing to retain the boot in said engagement with the housing.
16. The power tool assembly of claim 10 , wherein the housing further comprises a continuous layer of electrically insulative material affixed to an exterior surface of the layer of conductive material forming the first shield, and the boot further comprises a continuous layer of electrically insulative material affixed to an exterior surface of the layer of conductive material forming the second shield.
17. The power tool assembly of claim 10 , wherein the boot has an outer surface on which is printed human readable indicia comprising a warning message to the user of the power tool assembly associated with a high voltage.
18. The power tool assembly of claim 10 , further comprising an interlock mechanism that prevents activation of the electrical load by the control electronics circuit responsive to absence of the boot.
19. The power tool assembly of claim 10 , wherein the electrical load comprises a motor.
20. The power tool assembly of claim 10 , further comprising a suppression circuit disposed between the first and second shields.