Articulating drill with optical speed control and method of operation

• US 20070144872A1
• Filed: 11/03/2006
• Published: 06/28/2007
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: Credo Technology Corporation, Robert Bosch GmbH
• Original Assignee: Credo Technology Corporation, Robert Bosch GmbH
• Inventors: Pozgay, David, DeCicco, John, Kovarik, Illya
• Granted Patent: US 7,708,085 B2
• Time in Patent Office: Days
• US Class Current: 200/1.V
• CPC Class Codes: B25B 21/00 Portable power-driven screw or nut setting or loosening tools; details or components, e.g. casings, bodies, of portable power-driven tools not particularly related to the operation performed B25F5/00; for mounting or dismounting wheels B60B29/006; Attachments for drilling apparatus serving the same purpose machines B23P19/06
• CPC Class Codes: B25B 23/14 Arrangement of torque limiters or torque indicators in wrenches or screwdrivers couplings for transmitting rotation or clutches F16D; devices for measuring torque per se G01L
• CPC Class Codes: B25F 5/02 Construction of casings, bodies or handles B25F5/006, B25F5/008 take precedence
• CPC Class Codes: H01H 9/061 enclosing a continuously variable impedance
• CPC Class Codes: H02P 7/29 using pulse modulation
• CPC Class Codes: Y10S 388/937 Hand tool

Abstract

A power tool includes an optical speed control switch for controlling the variable speed of an electrical motor in the tool. The tool includes a moveable member having a reflective surface and the moveable member traversing a distance between a stop position and a full speed position, a biasing member operatively coupled to the moveable member to bias the moveable member toward the stop position, an optical signal generator for generating an optical signal, the optical signal generator being oriented so that the optical signal is directed toward the reflective surface of the moveable member, and a speed control signal generator for generating a speed control signal that corresponds to a reflection of the generated optical signal reflected by the reflective surface of the moveable member.

Claims

1. A power tool having an optical speed control switch comprising:

a moveable member having a reflective surface and the moveable member traversing a distance between a stop position and a full speed position,

a biasing member operatively coupled to the moveable member to bias the moveable member to the stop position,

an optical signal generator for generating an optical signal, the optical signal generator being oriented so that the optical signal is directed toward the reflective surface of the moveable member, and

a speed control signal generator for generating a speed control signal that corresponds to a reflection of the generated optical signal reflected by the reflective surface of the moveable member.

2. The tool of claim 1 wherein the moveable member comprises a pivoting trigger.

3. The tool of claim 1, wherein the moveable member comprises a dust cover.

4. The tool of claim 2 wherein the biasing member is a spring.

5. The tool of claim 1, the optical signal generator being an infrared (IR) signal generator.

6. The tool of claim 5, the speed control signal generator being an optical-transistor.

7. The tool of claim 6, the IR signal generator and the optical-transistor being located in a single housing having a sight glass for emitting the IR signal and receiving the reflected IR signal.

8. The tool of claim 6, the IR signal generator and the optical-transistor being located in a single housing having a first sight glass for the emitting the IR signal and a second sight glass for receiving the reflected IR signal.

9. The tool of claim 6 wherein the housing is smaller than a potentiometer having a wiper that travels a distance approximately the same as the distance traveled by the moveable member.

10. The tool of claim 1, wherein the tool is powered by a battery.

11. A method of controlling motor speed in a powered tool comprising:

traversing a distance between a stop position and a full speed position with a moveable member having a reflective surface,

biasing the moveable member toward the stop position,

directing an optical signal toward the reflective surface of the moveable member, and

generating a speed control signal that corresponds to a reflection of the generated optical signal reflected by the reflective surface of the moveable member.

12. The method of claim 11, the traversing of the moveable member further comprising:

pivoting a trigger through the distance between the stop and full speed positions.

13. The method of claim 11, the traversing of the moveable member further comprising:

moving a portion of a dust cover through the distance between the stop and full speed positions.

14. The method of claim 11, the biasing of the moveable member further comprising:

coupling a spring to the moveable member.

15. The method of claim 11, the optical signal directing including directing an infrared (IR) signal at the reflective surface of the moveable member.

16. The method of claim 15, the speed control signal generation further comprising:

controlling a current flow in accordance with an intensity of the optical signal being reflected by the reflective surface of the moveable member.

17. The method of claim 14, the controlling of the current flow further comprising:

receiving the reflected optical signal with an optical transistor.

18. The method of claim 17 further comprising:

locating the IR signal generator and the optical transistor in a single housing;

emitting the IR signal through a sight glass; and

receiving the reflected IR signal through the sight glass.

19. The method of claim 17 further comprising:

locating the IR signal generator and the optical transistor in a single housing;

emitting the IR signal through a first sight glass; and

receiving the reflected IR signal through a second sight glass.

20. The method of claim 19 further comprising:

sizing the housing to be smaller than a potentiometer having a wiper that travels a distance approximately the same as the distance traveled by the moveable member.