초록 ▼

An impact driver capable of boring and having an excellent usability is provided. An anvil(8) is arranged so as to slightly move in the axial direction. A first cam(29) having cam gears( 30, 30 . . . ) is externally provided at the anvil so as to be integral with the anvil(8). At the rear of the fi

An impact driver capable of boring and having an excellent usability is provided. An anvil(8) is arranged so as to slightly move in the axial direction. A first cam(29) having cam gears( 30, 30 . . . ) is externally provided at the anvil so as to be integral with the anvil(8). At the rear of the first cam(29) , a second cam(31) having cam gears(32, 32 . . . ) and further having cam gears(36, 36 . . . ) at its outer circumference is externally provided to the anvil(8) so as to be rotatable. At the backward position of the anvil(8), the cam gears(30, 32) contacts with each other. On the other hand, in the cylindrical portion(27) of the hammer case(5), an engaging pin(37 ) capable of engaging with an engaging gear(36) of the second cam(31) is provided. The engaging pin(37) can change its location by the rotative operation of a mode-change ring(40), whereby a percussion mode and a non-percussion mode is selected.

대표청구항 ▼

What is claimed is: 1. An impact driver comprising: a motor housed in a housing; an output shaft protruding from the housing and provided so as to slightly move back and forth in the axial direction; a rotation impact mechanism for transferring a motor torque to the output shaft while applying the

What is claimed is: 1. An impact driver comprising: a motor housed in a housing; an output shaft protruding from the housing and provided so as to slightly move back and forth in the axial direction; a rotation impact mechanism for transferring a motor torque to the output shaft while applying the impact operation in the rotative direction in accordance with increase of a torque load on the output shaft, a percussion application mechanism for generating percussion to the output shaft in the axial direction in accordance with rotation of the output shaft, and a regulating means, provided with the housing, which can from outside the housing arbitrarily select between a percussion mode in which the percussion application mechanism is activated and a non-percussion mode in which the percussion application mechanism is stopped, wherein the percussion application mechanism comprises: a first cam externally provided at the output shaft for rotating integrally with the same, a second cam inserted into the output shaft with play at the rear of the first cam, and the second cam is regulated in its moving in the axial direction, cam gears formed on the first and second cams at opposing faces thereof for contacting with each other at the backward position of the output shaft, and wherein by means of the regulating means, the percussion mode can be selected for regulating the rotation of the second cam and the non-percussion mode can be selected for releasing the regulation of the rotation of the second cam. 2. An impact driver as recited in claim 1, wherein the regulating means comprises an operating member provided at the outside of the housing and an engaging member moving inward and outward with respect to the second cam in accordance with the operation of the operating member to engage with the second cam at an inward position. 3. An impact driver as recited in claim 2, wherein the operating member is a cylindrical mode-change ring provided so as to be rotatable in the housing and having a concave portion in its inner circumference, and the engaging member is a pin member movable inward and outward with respect to the housing in the radial direction and being pressed in the direction away from the second cam to abut to the inner circumference of the mode-change ring, wherein with the rotative operation of the mode-change ring, the pin member moves outward to disengage from the second cam when the concave portion aligns with the pin member, and the pin member moves inward to engage with the second cam when the concave portion and the pin member are misaligned, respectively. 4. An impact driver comprising: a motor housed in a housing; an output shaft protruding from the housing and provided so as to slightly move back and forth in the axial direction; a rotation impact mechanism for transferring a motor torque to the output shaft while applying the impact operation in the rotative direction in accordance with increase of a torque load on the output shaft, a percussion application mechanism for generating percussion to the output shaft in the axial direction in accordance with rotation of the output shaft, and a regulating means, provided with the housing, which can from outside the housing arbitrarily select between a percussion mode in which the percussion application mechanism is activated and a non-percussion mode in which the percussion application mechanism is stopped, wherein at the top of the output shaft the impact driver has a chuck sleeve for attaching or detaching a tool on the output shaft by its sliding operation in the axial direction, wherein the percussion application mechanism comprises: a first cam being externally provided at the output shaft for rotating separately from the output shaft and on which a part of the chuck sleeve mounts externally, a second cam inserted into the output shaft with play at the rear of the first cam and fixed to the side of the housing, cam gears formed on the first and second cams at opposing faces thereof for contacting with each other at the backward position of the output shaft, and a regulating means provided between the chuck sleeve and the output shaft and capable of arbitrarily regulating the rotation of the first cam by means of the rotative operation of the chuck sleeve, and wherein by means of the regulating means, the percussion mode can be selected for regulating the rotation of the first cam and the non-percussion mode can be selected for releasing the regulation of the rotation of the first cam. 5. An impact driver as recited in claim 4, wherein the regulating means comprises a portion to be engaged provided at the outer circumference of the output shaft and an engaging member inserted into the first cam with play in the radial direction and moving inward and outward with respect to the output shaft in accordance with the rotative operation of the chuck sleeve for engaging with the portion to be engaged at an inward position. 6. An impact driver as recited in claim 5, wherein the portion to be engaged is a concave portion formed in the outer circumference of the output shaft and the regulating means is a pin member pressed in the direction away from the first cam to abut to the inner circumference of the chuck sleeve, wherein with the rotative operation of the chuck sleeve having a convex portion in its inner circumference, the pin member moves inward to engage with the concave portion when the convex portion aligns with the pin member, and the pin member moves outward to disengage from the concave portion when the convex portion and the pin member are misaligned, respectively.