Cordless concrete nailer with improved power take-off mechanism
A power take-off (PTO) assembly of a cordless electric concrete driver includes a bracket supporting a solenoid and a compression spring and a linkage arm coupled between a plunger of the solenoid and the compression spring. The linkage arm is biased by the compression spring toward the nail driver. A carrier supports or carries a pinch roller and the carrier is pivotably mounted to the bracket via a pivot pin. An engaging surface is movable with the plunger between an engagement position in which the engaging surface engages a cooperating engaging surface of the carrier and orients the carrier into a corresponding engagement orientation, and a disengagement position in which the engaging surface is spaced away from the cooperating engaging surface of the carrier, allowing the carrier to pivot outside the corresponding engagement orientation.
1. A cordless electric nailer comprising:
a power take-off (PTO) assembly positioned to selectively engage a nail driver against a battery-powered electric motor driven flywheel, the PTO assembly including:
a bracket supporting a solenoid and a compression spring;
a linkage arm coupled between a plunger of the solenoid and the compression spring, and the linkage arm being biased by the compression spring toward the nail driver;
a carrier supporting a pinch roller and the carrier being pivotably mounted to the bracket via a pivot pin;
an engaging surface movable with the plunger between an engagement position in which the engaging surface engages against a cooperating engaging surface of the carrier to orient the carrier into a corresponding engagement orientation when the solenoid is de-energized, and a disengagement position in which the engaging surface is spaced away from the cooperating engaging surface of the carrier to allow the carrier to pivot outside the corresponding engagement orientation when the solenoid is energized.
2. The cordless electric nailer of claim 1 , wherein the corresponding engagement orientation is limited to a single orientation of the carrier.
3. The cordless electric nailer of claim 2 , wherein the engaging surface and the cooperating engaging surface each comprise a linear surface, and the linear surfaces are in face-to-face contact in the engagement position.
4. The cordless electric nailer of claim 1 , wherein the corresponding engagement orientation includes an orientation of the carrier in which the carrier is in or adjacent an overcenter position with respect to an axis of the pivot pin and an axis of the pinch roller.
5. The cordless electric nailer of claim 1 , wherein the engaging surface is positioned adjacent a coupling that joins the plunger and the linkage arm together.
6. The cordless electric nailer of claim 5 , wherein the coupling directly couples the plunger to the linkage arm.
7. The cordless electric nailer of claim 1 , wherein a surface of a protrusion comprises the engaging surface.
8. The cordless electric nailer of claim 1 , wherein a surface of the linkage arm comprises the engaging surface.
9. The cordless electric nailer of claim 1 , wherein a surface of a protrusion of the linkage arm comprises the engaging surface.
10. The cordless electric nailer of claim 1 , wherein the engagement position corresponds to an extended position of the plunger.
11. The cordless electric nailer of claim 1 , wherein the disengagement position corresponds to a retracted position of the plunger.
12. The cordless electric nailer of claim 1 , wherein the cordless electric nailer is a concrete nailer.
13. The cordless electric nailer of claim 12 , wherein the compression spring of the concrete nailer provides a biasing force on the linkage arm that generates a compressive force on the nail driver through the pinch roller, and release of the compressive force imparts a pivot force on the carrier having a magnitude that is related to a magnitude of the compressive force.
14. The cordless electric nailer of claim 13 , wherein the engaging surface is in the disengagement position when the compressive force is released.
15. The cordless electric nailer of claim 13 , wherein a magnitude of the compressive force is at least 500 pounds per square inch.
16. The cordless electric nailer of claim 1 , wherein the linkage arm extends fully between the plunger and the compression spring.
17. The cordless electric nailer of claim 1 , wherein the pivot pin is a cam follower pin and is supported in slots of the bracket, and the linkage arm comprises a cam surface that the cam follower pin follows.
18. A cordless electric concrete nailer comprising:
a power take-off (PTO) assembly positioned to selectively engage a concrete nail driver against a battery-powered electric motor driven flywheel, the PTO assembly, including:
a bracket supporting a solenoid and a compression spring;
a linkage arm coupled between a plunger of the solenoid and the compression spring, and the linkage arm being biased by the compression spring toward the concrete nail driver;
a carrier supporting a pinch roller and the carrier being pivotably mounted to the bracket via a pivot pin;
an engaging surface movable with the plunger between an engagement position in which the engaging surface engages against a cooperating engaging surface of the carrier to orient the carrier into a corresponding engagement orientation when the solenoid is de-energized, and a disengagement position in which the engaging surface is spaced away from the cooperating engaging surface of the carrier to allow the carrier to pivot outside the corresponding engagement orientation when the solenoid is energized, wherein the compression spring of the concrete nailer provides a biasing force on the linkage arm that generates a compressive force of at least 500 pounds per square inch on the concrete nail driver through the pinch roller.
19. The cordless electric concrete nailer of claim 18 , wherein a surface of the linkage arm comprises the engaging surface.
20. The cordless electric nailer of claim 19 , wherein a surface of a protrusion of the linkage arm comprises the engaging surface.