Filing Information

Inventor(s)	Kevin L. Glasgow · Robert M. Crisp ·
Assignee(s)	Milwaukee Electric Tool Corporation ·  View assignee updates
Attorney/Agent(s)	Michael Best & Friedrich LLP ·
Primary Examiner	Rita Leykin ·
Application Number	US11537952
Filing date	10/02/2006
Issue date	10/16/2007
Prior Publication Data	US20070069672 - 03/29/2007
Predicted expiration date	12/06/2020
U.S. Classifications	318/280  · 318/289  · 318/283  · 318/286  · 318/282  · 222/638  · 222/626  · 318/281  ·
International Classifications	H02P700  ·
Kind Code	B2
Related U.S. Application Data	RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 10/996,564, filed Nov. 23, 2004 now U.S. Pat. No. 7,116,071, which is a continuation-in-part of U.S. patent application Ser. No. 10/152,059, filed May 21, 2002, now U.S. Pat. No. 6,823,134, issued Nov. 23, 2004, which is a continuation of U.S. patent application Ser. No. 09/731,438, filed Dec. 6, 2000, now U.S. Pat. No. 6,392,373, issued May 21, 2002. The contents of these applications and patents are hereby incorporated by reference in their entirety.

Patent Family

Abstract

A method and apparatus to automatically reverse the motor of a power tool, such as a dispensing gun or similar tool. In some constructions, a controller automatically reverses the direction of plunger movement and removes the plunger from contact with the back wall of a cartridge. The controller has a trigger switch that is coupled to a power source, such as a battery, and includes a main power on/off switch and a potentiometer. A protection or secondary switch is coupled in parallel to the main power on/off switch. A power supply circuit and a commutator are each coupled to the main and secondary switches. An overload sensor is coupled to the commutator. The controller includes a programmable device that is coupled to the power supply circuit, the potentiometer, the commutator, and the overload sensor. The programmable device is operable to sense actuation and deactuation of the main power on/off switch, read an electromotive force from the potentiometer, and, upon sensing deactuation of the main switch, send a control signal to the commutator to reverse current flow therethrough for a predetermined amount of time, and deactuate the secondary switch when the predetermined time has lapsed.

Independent Claims | See all claims (20)

1. 1. A power tool comprising: a housing; a motor supported by the housing; a trigger switch moveable in a first direction and a second direction; a controller coupled to the motor and the trigger switch, the motor operable in a first direction when the controller senses movement of the trigger switch in the first direction, and the motor operable in a second direction when the controller senses movement of the trigger switch in the second direction.
2. 9. A caulk gun comprising: a housing; a cradle supported by the housing and adapted to receive a caulk tube; a battery supported by the housing; a motor supported by the housing and selectively coupled to the battery, the motor operable in a first direction to dispense the caulk and in a second direction to reverse flow of the caulk; and a trigger switch supported by the housing and operable to actuate the motor in the first direction and the second direction the motor operable in the second direction when the trigger switch is deactuated.
3. 15. A method of dispensing material, the method comprising the acts of: depressing a trigger switch; actuating a motor in a first direction to move a plunger in a first direction, the plunger contacting the material housing to expel the material from the material housing; determining if the trigger switch has been depressed a predetermined distance; releasing the trigger switch; and actuating the motor in a second direction, if the trigger switch has been depressed the predetermined distance, to move the plunger in a second direction, the plunger moving out of contact with the material housing and reversing flow of the material.