Fastener-driving tool

1. A fastener-driving tool comprising:

a housing;

a shaft disposed in the housing;

a plunger surrounding the shaft and movable in an axial direction of the shaft;

a blade connected to the plunger and movable together with the plunger to impact a fastener;

a bumper and a bumper holder surrounding the shaft and arranged such that the plunger collides with the bumper when the blade impacts the fastener;

an adjuster having a cylindrical shape and threadingly engaged with the bumper holder to move the bumper holder in the axial direction by rotating the adjuster, the adjuster having an outer circumferential surface provided with one of a first recessed portion and a first protruding portion extending in the axial direction; and

an urging member fixed to the housing and protruding in a direction perpendicular to the axial direction of the shaft, the urging member having one of a second recessed portion and a second protruding portion,

wherein one of the second recessed portion and the second protruding portion is engaged with one of the first protruding portion and the first recessed portion.

2. The fastener-driving tool according to claim 1 , wherein the urging member is configured of a leaf spring provided on the housing.

3. The fastener-driving tool according to claim 2 , wherein the second protruding portion is formed by bending a portion of the urging member.

4. The fastener-driving tool according to claim 1 , wherein the first recessed portion includes a plurality of grooves formed on the outer circumferential surface of the adjuster and extending in the axial direction of the shaft.

5. The fastener-driving tool according to claim 1 , wherein the bumper holder is provided with a first threaded part extending in the axial direction, and

wherein the adjuster has a through hole, an inner peripheral surface of the through hole being provided with a second threaded part threadingly engaged with the first threading part.

6. A fastener-driving tool comprising:

a housing;

a shaft disposed in the housing;

a plunger surrounding the shaft and movable in an axial direction of the shaft;

a blade connected to the plunger and movable together with the plunger to impact a fastener;

a bumper disposed to overlap with the plunger in the one direction, the plunger configured to collide with the bumper when the blade impacts the fastener;

a bumper and a bumper holder surrounding the shaft and arranged such that the plunger collides with the bumper when the blade impacts the fastener, the bumper holder having a receiving surface for receiving the bumper and a first surface positioned on an opposite side of the receiving surface from the bumper, the bumper holder being provided with a first threaded part positioned on the opposite side of the receiving surface from the bummer;

an adjuster of cylindrical shape having a second surface opposed to the first surface and second threaded part threadingly engaged with the first threaded part to move the bumper holder in the axial direction by rotating the adjuster; and

a ring member disposed around the shaft and between the first surface of the bumper holder and the second surface of the adjuster.

7. The fastener-driving tool according to claim 6 , wherein the bumper holder is supported on

the shaft and rotatable around the shaft within a fixed amount of rotational angle.

8. The fastener-driving tool according to claim 6 , wherein the adjuster has an operating part for rotating thereof, and

wherein the housing is formed with an opening through which the operating part of the adjuster is exposed.

9. The fastener-driving tool according to claim 6 , wherein the ring member has a first spring coefficient for a deformation in the axial direction, and

wherein the first threaded part has a second spring coefficient for a deformation in the axial direction, the first coefficient being smaller than the second spring coefficient.

10. The fastener-driving tool according to claim 6 , wherein a deformation of the ring member is within an elastic deformation range thereof when the adjuster receives a rotational torque by rotating the adjuster such that the first surface approaches the second surface.

11. The fastener-driving tool according to claim 6 , wherein the first threaded part is configured of a male thread and extends in the axial direction from the first surface, and

wherein the second threaded part is configured of a female thread and threadingly engaged with the second threaded part.