Impact tool anvil brake mechanism
An anvil brake mechanism of an impact mechanism for an impact tool. In general, the impact mechanism is disposed within a housing of the impact tool and includes a gear carrier, a hammer, an anvil, and an anvil brake mechanism. The anvil brake mechanism may restrict the anvil from rotating backwards or oscillating after the hammer impacts the anvil. This may increase the efficiency of the impact from the hammer to the anvil as well as reduce wear on the anvil.
1 . An impact mechanism for an impact tool, the impact mechanism comprising:
a hammer including a hammer lug;
an anvil including an anvil aperture, an inner surface formed by the anvil aperture, and an impact section adapted to receive a rotational impact force from the hammer lug;
a gear carrier including opposing first and second end portions, wherein the first end portion is adapted to be rotatably driven by a motor and the second end portion is adapted to be disposed in the anvil aperture; and
an O-ring adapted to be disposed in the anvil aperture and around the second end portion, wherein the O-ring is adapted to frictionally engage the inner surface to restrict the anvil from rotating backwards when the impact section receives the rotational impact force from the hammer lug.
2 . The impact mechanism of claim 1 , wherein the O-ring is constructed of rubber.
3 . The impact mechanism of claim 1 , wherein the O-ring is adapted to seal a lubricating material within the impact tool.
4 . The impact mechanism of claim 1 , further comprising a receiving groove formed in the inner surface, wherein the O-ring is adapted to be disposed in the receiving groove.
5 . An impact mechanism for an impact tool, the impact mechanism comprising:
a hammer including a hammer lug;
an anvil including an anvil end surface, an anvil aperture extending into the anvil end surface, and an impact section adapted to receive a rotational impact force from the hammer lug;
a gear carrier including a body portion and opposing first and second end portions, wherein the first end portion is adapted to be rotatably driven by a motor and the second end portion is adapted to be disposed in the anvil aperture;
a thrust washer adapted to be disposed around the second end portion between the anvil end surface and the body portion; and
a biasing washer adapted to be disposed around the second end portion between the thrust washer and the anvil end surface, wherein the biasing washer is adapted to engage the anvil end surface to restrict the anvil from rotating backwards when the impact section receives the rotational impact force from the hammer lug.
6 . The impact mechanism of claim 5 , wherein the biasing washer is a Belleville washer.
7 . The impact mechanism of claim 5 , wherein the biasing washer is a coil spring.
8 . The impact mechanism of claim 5 , wherein the biasing washer is adapted to apply a variable bias force to the anvil end surface.
9 . An impact mechanism for an impact tool, the impact mechanism comprising:
a hammer including a hammer lug;
an anvil including an output shaft and an impact section adapted to receive a rotational impact force from the hammer lug;
a gear carrier adapted to be rotatably driven by a motor and operably coupled to the anvil; and
a clutch disposed on the output shaft of the anvil and adapted to engage the anvil to restrict the anvil from rotating backwards when the impact section receives the rotational impact force from the hammer lug.
10 . The impact mechanism of claim 9 , wherein the clutch includes an outer race, and an engagement feature coupled to the outer race and adapted to engage the anvil.
11 . The impact mechanism of claim 10 , wherein the engagement feature includes sprags.
12 . The impact mechanism of claim 10 , wherein the engagement feature includes a clutch plate.
13 . The impact mechanism of claim 10 , wherein the engagement feature includes a brake shoe.
14 . The impact mechanism of claim 9 , wherein the clutch is adapted to provide a fixed load to the anvil.
15 . The impact mechanism of claim 9 , wherein the engaging device is adapted to provide a variable load to the anvil.