Modular Router With Base Sensor

• US 20100206429A1
• Filed: 02/13/2009
• Published: 08/19/2010
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Credo Technology Corporation, Robert Bosch GmbH
• Original Assignee: Credo Technology Corporation, Robert Bosch GmbH
• Inventors: Pozgay, David, Schreiner, Jeff, Ren, Charlie
• Granted Patent: US 7,921,889 B2
• Time in Patent Office: Days
• US Class Current: 144/136.950
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: B27C 5/10 Portable hand-operated wood-milling machines; Routers
• CPC Class Codes: Y10T 409/306608 End mill [e.g., router, etc.]

Abstract

A power tool comprises a base unit and a motor unit. The base unit includes a handle and a first electrical connector. The motor unit includes an electric motor and a second electrical connector. The motor unit is configured to be releasably connected to the base unit. An electrical connection is established between the first electrical connector and the second electrical connector when the motor unit is properly connected to the base unit. A sensor is configured to determine whether the motor unit is properly connected to the base unit.

Claims

1. A power tool comprising:

a base unit including a handle and a first electrical connector;

a motor unit configured to be releasably connected to the base unit, the motor unit including an electric motor and a second electrical connector, wherein an electrical connection is established between the first electrical connector and the second electrical connector when the motor unit is properly connected to the base unit; and

a sensor configured to determine whether the motor unit is properly connected to the base unit.

2. The power tool of claim 1 wherein the sensor is configured to determine a plurality of electrical signals on a plurality of conductors in order to determine that the motor unit is properly connected to the base unit.

3. The power tool of claim 2 wherein the sensor comprises a resistive network at least partially positioned on the motor unit.

4. The power tool of claim 2 further comprising a power control circuit configured to control power to the electric motor, wherein the power control circuit is configured to deprive the electric motor of power when the sensor determines that the motor unit is not properly connected to the base unit.

5. The power tool of claim 4 further comprising a switch positioned on the handle of the base unit, the switch moveable between an on position and an off position.

6. The power tool of claim 5 wherein the power control circuit is configured to control power to the electric motor depending upon the position of the switch on the handle.

7. The power tool of claim 6 wherein the power control circuit is configured to determine if a fault condition exists in the power control circuit, the fault condition resulting in power being delivered to the electric motor after the switch on the handle is moved to the off position.

8. The power tool of claim 7 wherein the power control circuit includes a relay controlled by a microprocessor, the microprocessor configured to determine if the fault condition exists.

9. The power tool of claim 7 wherein the power control circuit includes a triac controlled by a microprocessor, the microprocessor configured to determine if the fault condition exists.

10. The power tool of claim 1 wherein the sensor comprises a microprocessor configured to receive an electrical signal indicating that the motor unit is properly connected to the base unit.

11. A modular power tool comprising:

a first base unit including a motor power switch moveable between an on position and an off position;

a second base unit including a motor power switch movable between an on position and an off position;

a motor unit configured for releasable connection to either the first base unit or the second base unit, the motor unit including an electric motor, wherein an electrical connection is established between the motor unit and either the first base unit or the second base unit when the motor unit is connected to the respective first base unit or second base unit; and

a power control circuit configured to control electrical power delivery to the electric motor, the power control circuit configured to deprive the electric motor of electrical power when the motor unit is not properly connected to either the first base unit or the second base unit.

12. The modular power tool of claim 11 wherein the power control circuit is further configured to deprive the electric motor of electrical power if a fault condition exists, the wherein fault condition results in power being delivered to the electric motor after the motor power switch is moved to the off position.

13. The modular power tool of claim 11 further comprising a sensor configured to determine whether the motor unit is properly connected to either the first base unit or the second base unit.

14. The modular power tool of claim 11 wherein the power control circuit is configured to deliver electrical power to the electric motor only if an electrical connection is established between the motor unit and either the first base unit or second base unit and if the motor power switch is in the on position for the respective first base unit or second base unit.

15. The modular power tool of claim 11 wherein the first base unit includes a handle and the motor power switch is positioned on the handle.

16. The modular power tool of claim 11 wherein the first base unit is a fixed base for a router.

17. The modular power tool of claim 11 wherein the second base unit is a plunge base for a router.

18. The modular power tool of claim 12 wherein the power control circuit includes a relay controlled by a microprocessor, the microprocessor configured to determine if the fault condition exists.

19. The modular power tool of claim 12 wherein the power control circuit includes a triac controlled by a microprocessor, the microprocessor configured to determine if the fault condition exists.

20. A power tool comprising:

a base unit including a first electrical connector, a handle, and a motor power switch positioned on the handle, the motor power switch moveable between a first position and a second position;

a motor unit releasably connected to the base unit, the motor unit including an electric motor and a second electrical connector, wherein an electrical connection is established between the first electrical connector and the second electrical connector when the motor unit is properly connected to the base unit; and

a power control circuit configured to deliver electrical power to the electric motor if an electrical connection exists between the first electrical connector and the second electrical connector and if the motor power switch on the handle is in an on position,

wherein the power control circuit is further configured to determine if a fault condition exists in the power control circuit, the fault condition resulting in power being delivered to the electric motor after the motor power switch on the handle is moved to the off position, and wherein the power control circuit is configured to open the power control circuit if the fault condition exists.