US-12617062-B2 - Power tool sensing a multi-pole magnet junction

Abstract

A powered fastener driver includes a motor and a lifter configured to be rotatable by the motor about a rotational axis. The powered fastener driver also includes a piston urged towards a bottom-dead-center position to drive the fastener into a workpiece, and a magnet coupled to the lifter for rotation with the lifter. The magnet includes a first pair of poles including a first north pole face and a first south pole face, and a second pair of poles including a second north pole face and a second south pole face. The first north pole face is adjacent the second south pole face. A pole junction is defined between the first pair of poles and the second pair of poles. The powered fastener driver also includes a sensor configured to detect the pole junction, and a controller configured to control the motor based on detection of the pole junction.

Inventors

• Andrew R. Palm

Assignees

• MILWAUKEE ELECTRIC TOOL CORPORATION

Dates

Publication Date

20260505

Application Date

20241122

Claims (20)

1. 1 . A powered fastener driver, comprising: a motor; a lifter configured to be rotatable by the motor about a rotational axis; a piston urged towards a bottom-dead-center position to drive the fastener into a workpiece; a magnet coupled to the lifter for rotation with the lifter, the magnet including a first pair of poles including a first north pole face and a first south pole face, and a second pair of poles including a second north pole face and a second south pole face, wherein the first north pole face is adjacent the second south pole face, and wherein a pole junction is defined between the first pair of poles and the second pair of poles; a sensor configured to detect the pole junction; and a controller configured to control the motor based on detection of the pole junction.
2. 2 . The powered fastener driver of claim 1 , wherein the pole junction is configured to be detected by the sensor when the lifter reaches an intermediate ready position, and wherein the controller is configured to stop the motor in response to the lifter reaching the intermediate ready position.
3. 3 . The powered fastener driver of claim 1 , wherein the magnet is disposed on an outer circumference of the lifter.
4. 4 . The powered fastener driver of claim 1 , wherein the first north pole face and the first south pole face are each configured to face the sensor.
5. 5 . The powered fastener driver of claim 1 , wherein the sensor is a North pole-detecting Hall-effect sensor configured to filter for North pole flux or a South pole-detecting Hall-effect sensor configured to filter for South pole flux.
6. 6 . The powered fastener driver of claim 1 , wherein the lifter includes first and second eccentric pins configured to selectively engage the piston, wherein the first eccentric pin is disposed a first radial distance with respect to the rotational axis, wherein the second eccentric pin is disposed a second radial distance with respect to the rotational axis, and wherein the first and second radial distances are different from each other.
7. 7 . The powered fastener driver of claim 6 , wherein the first eccentric pin is shorter than the second eccentric pin.
8. 8 . A powered fastener driver, comprising: a motor; a contact trip configured to be movable from a first position to a second position in response to engagement with a workpiece; a magnet coupled to the contact trip for movement with the contact trip, the magnet including a first pair of poles including a first north pole face and a first south pole face, and a second pair of poles including a second north pole face and a second south pole face, wherein the first north pole face is adjacent the second south pole face, and wherein a pole junction is defined between the first pair of poles and the second pair of poles; a sensor configured to detect the pole junction; and a controller configured to deactivate the motor to inhibit release of a fastener when the contact trip is in the first position based on detection of the pole junction.
9. 9 . The powered fastener driver of claim 8 , wherein the pole junction is configured to be detected by the sensor when the contact trip is in the first position, wherein the controller is configured to deactivate the motor in response to the contact trip being in the first position.
10. 10 . The powered fastener driver of claim 8 , wherein the pole junction is configured to be detected by the sensor when the contact trip is in the second position, wherein the controller is configured to allow activation of the motor in response to the contact trip being in the second position.
11. 11 . The powered fastener driver of claim 8 , wherein the first north pole face and the first south pole face are each configured to face the sensor.
12. 12 . The powered fastener driver of claim 8 , wherein the sensor is a North pole-detecting Hall-effect sensor configured to filter for North pole flux or a South pole-detecting Hall-effect sensor configured to filter for South pole flux.
13. 13 . The powered fastener driver of claim 8 , wherein the contact trip includes a main body elongated generally parallel to a fastener drive axis, and a support portion extending from the main body, the support portion configured to support the magnet such that the magnet moves fixedly with the contact trip.
14. 14 . The powered fastener driver of claim 13 , wherein the support portion extends laterally from the main body.
15. 15 . The powered fastener driver of claim 8 , wherein the magnet includes a third pair of poles and a second pole junction.
16. 16 . A powered fastener driver, comprising: a motor; a lifter configured to be rotatable by the motor about a rotational axis; a piston urged towards a bottom-dead-center position to drive the fastener into a workpiece; a contact trip configured to be movable from a first position to a second position in response to engagement with the workpiece; a first magnet coupled to the lifter for rotation with the lifter, the first magnet including a first pair of poles, a second pair of poles, and a first pole junction therebetween; a first sensor configured to detect the first pole junction; a second magnet coupled to the contact trip for movement with the contact trip, the second magnet including a third pair of poles, a fourth pair of poles, and a second pole junction therebetween; a second sensor configured to detect the second pole junction; and a controller configured to stop the motor based on a position of the first pole junction, and configured to deactivate the motor to inhibit release of a fastener based on a position of the second pole junction.
17. 17 . The powered fastener driver of claim 16 , further comprising a trigger configured to actuate the motor, wherein the controller is further configured stop the motor based on the position of the first pole junction when the first sensor detects the lifter in an intermediate ready position, and is further configured to initiate rotation of the motor in a new drive cycle when the second sensor detects the contact trip is moved out of the first position and the trigger is subsequently actuated.
18. 18 . The powered fastener driver of claim 16 , wherein the first sensor is a North pole-detecting Hall-effect sensor configured to filter for North pole flux or a South pole-detecting Hall-effect sensor configured to filter for South pole flux, and wherein the second sensor is a North pole-detecting Hall-effect sensor configured to filter for North pole flux or a South pole-detecting Hall-effect sensor configured to filter for South pole flux.
19. 19 . The powered fastener driver of claim 16 , wherein the lifter includes first and second eccentric pins configured to selectively engage the piston, wherein the first eccentric pin is disposed a first radial distance with respect to the rotational axis, wherein the second eccentric pin is disposed a second radial distance with respect to the rotational axis, wherein the first and second radial distances are different from each other, and wherein the first eccentric pin is shorter than the second eccentric pin.
20. 20 . The powered fastener driver of claim 16 , wherein the contact trip includes a main body elongated generally parallel to a fastener drive axis, and a support portion extending from the main body, the support portion configured to support the second magnet such that the second magnet moves fixedly with the contact trip.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 18/348,858, filed on Jul. 7, 2023, now U.S. Pat. No. 12,186,870, which claims priority to U.S. Provisional Patent Application No. 63/359,534, filed on Jul. 8, 2022, the entire contents of both of which are incorporated herein by reference. BACKGROUND The present disclosure relates to a power tool, such as a powered fastener driver, and more particularly to a battery powered power tool. There are various power tools known in the art. For example, fastener drivers are known in the art for driving fasteners (e.g., nails, tacks, staples, rivets, etc.) into a workpiece. These fastener drivers operate utilizing various means known in the art (e.g., compressed air generated by an air compressor, electrical energy, a flywheel mechanism, etc.), but often these designs are met with power, size, and cost constraints. SUMMARY In one aspect, the disclosure provides a powered fastener driver. The powered fastener driver includes a motor and a lifter configured to be rotatable by the motor about a rotational axis. The powered fastener driver also includes a piston urged towards a bottom-dead-center position to drive the fastener into a workpiece, and a magnet coupled to the lifter for rotation with the lifter. The magnet includes a first pair of poles including a first north pole face and a first south pole face, and a second pair of poles including a second north pole face and a second south pole face. The first north pole face is adjacent the second south pole face. A pole junction is defined between the first pair of poles and the second pair of poles. The powered fastener driver also includes a sensor configured to detect the pole junction, and a controller configured to control the motor based on detection of the pole junction. In another aspect, the disclosure provides a powered fastener driver including a motor, a contact trip configured to be movable from a first position to a second position in response to engagement with a workpiece, and a magnet coupled to the contact trip for movement with the contact trip. The magnet includes a first pair of poles including a first north pole face and a first south pole face, and a second pair of poles including a second north pole face and a second south pole face. The first north pole face is adjacent the second south pole face. A pole junction is defined between the first pair of poles and the second pair of poles. The powered fastener driver also includes a sensor configured to detect the pole junction, and a controller configured to deactivate the motor to inhibit release of a fastener when the contact trip is in the first position based on detection of the pole junction. In another aspect, the disclosure provides a powered fastener driver including a motor and a lifter configured to be rotatable by the motor about a rotational axis. The powered fastener driver also includes a piston urged towards a bottom-dead-center position to drive the fastener into a workpiece, a contact trip configured to be movable from a first position to a second position in response to engagement with the workpiece, and a first magnet coupled to the lifter for rotation with the lifter. The first magnet includes a first pair of poles, a second pair of poles, and a first pole junction therebetween. The powered fastener driver also includes a first sensor configured to detect the first pole junction, and a second magnet coupled to the contact trip for movement with the contact trip. The second magnet includes a third pair of poles, a fourth pair of poles, and a second pole junction therebetween. The powered fastener driver also includes a second sensor configured to detect the second pole junction, and a controller configured to stop the motor based on a position of the first pole junction and configured to deactivate the motor to inhibit release of a fastener based on a position of the second pole junction. Other features and aspects of the disclosure will become apparent by consideration of the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a powered fastener driver. FIG. 2 is a side view of the powered fastener driver of FIG. 1, with portions removed for clarity, illustrating a drive mechanism, a firing mechanism, and a lifter assembly. FIG. 3 is a side view of the drive mechanism, the firing mechanism, and the lifter assembly of the powered fastener driver of FIG. 1. FIG. 4 is a perspective view of a portion of the lifter assembly and the firing mechanism of FIG. 3. FIG. 5 is a perspective view of the portion of the lifter assembly shown in FIG. 4. FIG. 6 is a top view of the portion of the lifter assembly shown in FIG. 5. FIG. 7 is a top view of a contact trip of the powered fastener driver of FIG. 1, illustrated in a first position. FIG. 8 is a top view of the contact trip of the powered fastener driver of