Trigger assembly

Patent metadata

Field	Value
Publication number	US-2018091145-A1
Application number	US-201715714220-A
Country	US
Kind code	A1
Filing date	Sep 25, 2017
Priority date	Sep 28, 2016
Publication date	Mar 29, 2018
Grant date	—

Abstract

A trigger assembly, for use with a power tool having an electric motor, includes a trigger, a conductor coupled for movement with the trigger, and a printed circuit board. The printed circuit board has an inductive sensor thereon responsive to relative movement between the conductor and the inductive sensor caused by movement of the trigger. An output of the inductive sensor is used to activate the electric motor.

First claim

What is claimed is:

1 . A trigger assembly for use with a power tool having an electric motor, the trigger assembly comprising:
a trigger; a conductor coupled for movement with the trigger; a printed circuit board having an inductive sensor thereon responsive to relative movement between the conductor and the inductive sensor caused by movement of the trigger, wherein an output of the inductive sensor is used to activate the electric motor.

2 . The trigger assembly of claim 1 , wherein the inductive sensor is first inductive sensor, the conductor is a first conductor, and the output is a first output, and wherein the trigger assembly further comprises
a second conductor coupled for movement with the trigger, and a second inductive sensor on the printed circuit board responsive to relative movement between the second conductor and the second inductive sensor caused by movement of the trigger, wherein a second output of the second inductive sensor is used to activate the electric motor.

3 . The trigger assembly of claim 2 , wherein the first output of the first inductive sensor is used to activate the electric motor in a first rotational direction, and wherein the second output of the second inductive sensor is used to activate the electric motor in a second rotational direction that is different than the first rotational direction.

4 . The trigger assembly of claim 1 , wherein the inductive sensor is a coil trace having a proximal end located proximate the trigger and a distal end, and wherein the distal end has a different winding density than the proximal end.

5 . The trigger assembly of claim 4 , wherein, in response to the conductor moving away from the proximal end of the inductive sensor and towards the distal end, a rotational speed of the motor is accelerated, and wherein in response to the conductor moving away from the distal end of the inductive sensor and towards the proximal end, the rotational speed of the motor is decelerated.

6 . The trigger assembly of claim 5 , further comprising a spring biasing the trigger toward a neutral position in which the conductor is closer to the proximal end than the distal end.

7 . The trigger assembly of claim 6 , wherein the coil trace is linear.

8 . The trigger assembly of claim 6 , wherein the coil trace is curvilinear.

9 . The trigger assembly of claim 8 , wherein the conductor is a first conductor, the coil trace is a first coil trace, and the output is a first output used to activate the motor in a first rotational direction, and wherein the trigger assembly further comprises
a second conductor coupled for movement with the trigger, and a second inductive sensor configured as a second coil trace on the printed circuit board having a proximal end located proximate the trigger and a distal end, wherein the distal end of the second coil trace has a different winding density than the proximal end of the second coil trace, wherein the second inductive sensor is responsive to relative movement between the second conductor and the second inductive sensor caused by movement of the trigger, and wherein a second output of the second inductive sensor is used to activate the motor in a second rotational direction that is different than the first rotational direction, wherein, in response to the second conductor moving away from the proximal end of the second coil trace and towards the distal end of the second coil trace, a rotational speed of the electric motor is accelerated, and wherein in response to the second conductor moving away from the distal end of the second coil trace and towards the proximal end of the second coil trace, the rotational speed of the motor is decelerated.

10 . The trigger assembly of claim 1 , wherein the inductive sensor is a coil trace having a first end and a second end that has a different coil density than the first end, and wherein the trigger assembly further comprises
a spring biasing the trigger to a position in which the conductor is located in a neutral position between the first end and the second end, wherein, in response to the conductor moving away from the neutral position and towards the first end of the coil trace, the output of the inductive sensor is used to activate the motor in a first rotational direction and to accelerate a rotational speed of the motor, and wherein, in response to the conductor moving away from the neutral position and towards the second end of the coil trace, the output of the inductive sensor is used to activate the motor in an opposite, second rotational direction and to accelerate a rotational speed of the motor.

11 . A power tool comprising:
an electric motor; a controller in electrical communication with the motor to activate and deactivate the motor; a trigger; a conductor coupled for movement with the trigger; and a printed circuit board having an inductive sensor thereon responsive to relative movement between the conductor and the inductive sensor caused by movement of the trigger; wherein an output of the inductive sensor is detected by the controller, which in response activates or deactivates the electric motor.

12 . The power tool of claim 11 , wherein the inductive sensor is first inductive sensor, the conductor is a first conductor, and the output is a first output, and wherein the power tool further comprises
a second conductor coupled for movement with the trigger, and a second inductive sensor on the printed circuit board responsive to relative movement between the second conductor and the second inductive sensor caused by movement of the trigger, wherein a second output of the second inductive sensor is detected by the controller, which in response activates the electric motor.

13 . The power tool of claim 12 , wherein the first output of the first inductive sensor is detected by the controller, which in response activates the electric motor in a first rotational direction, and wherein the second output of the second inductive sensor is detected by the controller, which in response activates the electric motor in a second rotational direction that is different than the first rotational direction.

14 . The power tool of claim 11 , wherein the inductive sensor is a coil trace having a proximal end located proximate the trigger and a distal end, and wherein the distal end has a different winding density than the proximal end.

15 . The power tool of claim 14 , wherein, in response to the conductor moving away from the proximal end of the inductive sensor and towards the distal end, a rotational speed of the motor is accelerated by the controller, and wherein, in response to the conductor moving away from the distal end of the inductive sensor and towards the proximal end, the rotational speed of the motor is decelerated by the controller.

16 . The power tool of claim 15 , further comprising a spring biasing the trigger toward a neutral position in which the conductor is closer to the proximal end than the distal end.

17 . The power tool of claim 16 , wherein the conductor is a first conductor, the coil trace is a first coil trace, and the output is a first output detected by the controller to activate the motor in a first rotational direction, and wherein the power tool further comprises
a second conductor coupled for movement with the trigger, and a second inductive sensor configured as a second coil trace on the printed circuit board having a proximal end located proximate the trigger and a distal end, wherein the distal end of the second coil trace has a different winding density than the proxim

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Dey Iv John S
• Schneider Jacob P

Classifications

• H03K2017/9706

  Inductive element · CPC title

• H03K17/97

  using a magnetic movable element · CPC title

• H01F5/003

  Printed circuit coils · CPC title

• G01D5/202 Primary

  by movable a non-ferromagnetic conductive element (G01D5/2033 takes precedence) · CPC title

• H03K17/9618 Primary

  using a plurality of detectors, e.g. keyboard · CPC title