Handheld low voltage machining tool
First Claim
1. A handheld low voltage machining tool comprising a handpiece having securing means for rotatably securing one of a plurality of different machining tool bits in an exchangeable manner and an electric drive motor for rotating said securing means;
- an electrically conductive probe; and
a control unit that is connectable to said probe for supplying power thereto, said control unit being connectable to said handpiece for controlling operation thereof;
wherein said control unit includes brake means for stopping rotation of said tool bit, and brake control means for detecting when said probe and a machining tool bit secured in said holding means are brought into contact with a common electrically conductive path.
1 Assignment
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Accused Products
Abstract
A handheld low voltage machining tool with which any one or more of drilling, milling, and abrading operations can be safely performed even on densely populated, multilayer, circuit boards. Provisions are made for preventing electrical overstress by isolating the tip of the machining tool from the drive motor as well as for preventing abrupt starting of the tool which can cause jerking, jumping or skipping of the tool off of the target. Still further, dynamic braking of the tool bit is achieved, both upon release of an operator actuated control switch and due to a selected conductive layer being reached. For the latter effect, a probe is provided by which a low voltage can be delivered to a component or conductor on the board, and circuitry detects grounding of this voltage by contact with the grounded bit of the machining tool.
63 Citations
20 Claims
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1. A handheld low voltage machining tool comprising a handpiece having securing means for rotatably securing one of a plurality of different machining tool bits in an exchangeable manner and an electric drive motor for rotating said securing means;
- an electrically conductive probe; and
a control unit that is connectable to said probe for supplying power thereto, said control unit being connectable to said handpiece for controlling operation thereof;
wherein said control unit includes brake means for stopping rotation of said tool bit, and brake control means for detecting when said probe and a machining tool bit secured in said holding means are brought into contact with a common electrically conductive path. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- an electrically conductive probe; and
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13. A method of controlling machining of a circuit board comprising the steps of:
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connecting a handpiece, having securing means for rotatably securing one of a plurality of different machining tool bits in an exchangeable manner and an electric drive motor for rotating said securing means, to a control unit for controlling operation thereof; connecting an electrically conductive probe to said control unit for supplying power thereto; connecting an end of said probe to an electrically conductive path of said circuit board; supplying power to said electrically conductive path via said probe while machining said circuit board by rotating a tool bit secured to said handpiece; and immediately stopping rotation of said tool bit in response brake control means of said control unit detecting the tool bit secured to said handpiece being brought into contact with said electrically conductive path. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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Specification