Powered cutting tool

Patent metadata

Field	Value
Publication number	US-9757868-B2
Application number	US-201615096338-A
Country	US
Kind code	B2
Filing date	Apr 12, 2016
Priority date	Oct 8, 2010
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A cutting tool includes a housing and a pair of cutting blades at least partially extending from the housing. At least a first of the cutting blades is movable. The cutting tool also includes a drive mechanism including a cam and a ratchet mechanism. At least a portion of the ratchet mechanism is drivably coupled to the first cutting blade. The cutting tool further includes a motor for providing torque to the cam to actuate the ratchet mechanism. The ratchet mechanism includes a follower that is translatable in a direction transverse to a rotational axis of the cam in response to rotation of the cam.

First claim

What is claimed is:

1. A cutting tool comprising:
a housing;
a pair of cutting blades at least partially extending from the housing, at least a first of the cutting blades is movable;
a drive mechanism including a cam and a ratchet mechanism, at least a portion of the ratchet mechanism is drivably coupled to the first cutting blade;
a motor for providing torque to the cam to actuate the ratchet mechanism; and
a planetary transmission between the motor and the cam, the transmission including a carrier directly connected to the cam,
wherein the ratchet mechanism includes a follower that is translatable in a direction transverse to a rotational axis of the cam in response to rotation of the cam.

2. The cutting tool of claim 1 , wherein a second of the cutting blades is fixed relative to the housing.

3. The cutting tool of claim 1 , further comprising an output shaft rotatably supported within the housing, wherein the first cutting blade is coupled for co-rotation with the output shaft, and wherein a second of the cutting blades is pivotably supported by the output shaft.

4. The cutting tool of claim 3 , further comprising a securing member that is movable between a first position, in which the second cutting blade is secured relative to the housing, and a second position, in which limited pivoting movement of the second cutting blade about the output shaft is permitted.

5. The cutting tool of claim 3 , wherein the output shaft includes a shoulder for maintaining a gap between the cutting blades.

6. The cutting tool of claim 1 , further comprising an output shaft rotatably supported within the housing, wherein the first cutting blade is coupled for co-rotation with the output shaft, and wherein the ratchet mechanism includes
a ratchet coupled for co-rotation with the first cutting blade,
a link having a first end pivotably coupled to the output shaft and a second end that is movable in response to rotation of the cam, and
a pawl coupled to the link between the first and second ends and engaged with the ratchet.

7. The cutting tool of claim 6 , wherein the follower is pivotably coupled to the second end of the link and engaged with the cam.

8. The cutting tool of claim 7 , wherein the follower includes a roller engaged with the cam.

9. The cutting tool of claim 6 , wherein the pawl is pivotably coupled to the link and movable between a first position, in which the pawl is engaged with the ratchet, and a second position, in which the pawl is disengaged from the ratchet.

10. The cutting tool of claim 6 , wherein the pawl is a first pawl, and wherein the ratchet mechanism further includes a second pawl pivotably coupled to the housing and engaged with the ratchet.

11. The cutting tool of claim 10 , further comprising an actuator engageable with the first and second pawls, and wherein the actuator is movable between a first, biased position in which the first and second pawls are permitted to engage the ratchet, and a second position in which the actuator disengages the first and second pawls from the ratchet.

12. The cutting tool of claim 11 , wherein the ratchet mechanism further includes
a lever coupled for co-rotation with the first pawl,
a support shaft upon which the second pawl is coupled for co-rotation, and
an arm coupled to the support shaft for co-rotation with the support shaft and the second pawl.

13. The cutting tool of claim 12 , wherein the actuator includes
a first cam lobe engageable with the lever when in the second position, and
a second cam lobe engageable with the arm when in the second position.

14. The cutting tool of claim 11 , further comprising
a first trigger operable to activate the motor, and
a second trigger operably coupled to the actuator for moving the actuator between the first and second positions.

15. The cutting tool of claim 14 , wherein the second trigger is positioned proximate the first trigger such that an operator can grasp the first and second triggers with a single hand.

16. The cutting tool of claim 14 , wherein the second trigger is pivotable between the first and second positions.

17. The cutting tool of claim 6 , wherein the ratchet is rotatable in a first direction, against the bias of a spring, in response to actuation of the ratchet mechanism by the motor.

18. The cutting tool of claim 1 , further comprising:
an electronic braking circuit for normally providing a braking force to the motor in response to deactivation of the motor; and
a current overload detection circuit for monitoring an amount of electrical current drawn by the motor when the motor is activated;
wherein the current overload detection circuit both deactivates the motor and overrides the electronic braking circuit in response to the motor exceeding a threshold electrical current to prevent application of the braking force to the motor.

19. The cutting tool of claim 1 , further comprising:
a switch electrically connected with the motor and actuated between a first position in which the motor is activated and a second position in which the motor is deactivated;
a current overload detection circuit for monitoring an amount of electrical current drawn by the motor when the motor is activated; and
a reversing circuit for reversing a rotational direction of the motor in response to at least one of the motor exceeding a threshold electrical current and the switch being actuated from the first position to the second position.

20. The cutting tool of claim 1 , further comprising a direction switch electrically connected with the motor and actuated between a first position in which the motor and the cam are driven in a forward direction, and a second position in which the motor and the cam are driven in a reverse direction.

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Winkel Steven N
• Thorson Troy C
• Gehring Todd M
• Strohfeldt William W
• Mergener Matthew
• Anderson Scott

Classifications

• B23Q15/007

  while the tool acts upon the workpiece · CPC title

• B26B15/00 Primary

  Hand-held shears with motor-driven blades · CPC title