US 7,861,799 B2Granted

Impact tool

AssigneeMakita Corporation

InventorsJunichi Iwakami, Shinji Onoda, Takamasa Hanai

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Abstract

It is an object of the invention to provide a technique which is effective in improving the durability of an angular positioning device of a tool bit and in reducing weight of a tool body in an impact tool. A representative impact tool includes a tool body, a lubricant sealed in the housing space, a driving mechanism, a tool holder, an angular positioning device disposed on a tip end side of the tool body and serves to fix a position of the tool bit around the axis with respect to the tool body. The angular positioning device includes first and second locking members. The first locking member is disposed between the tool body and the tool holder. The second locking member is disposed opposite to the first locking member. One end of the first locking member in the axial direction of the tool bit extends into the housing space of the tool body and is connected to the tool body within the housing space.

Claims11

Dependent claims

An impact tool performing a predetermined hammering operation on a workpiece by a striking movement of a tool bit in an axial direction of the tool bit, comprising:

a tool body having a housing space,
a lubricant sealed in the housing space,
a driving mechanism that is housed within the housing space and drives the tool bit disposed in a tip end region of the tool body in the axial direction,
a tool holder that holds the tool bit in such a manner that the tool bit cannot rotate around an axis of the tool bit with respect to the tool holder, the tool holder being disposed in the tool body in such a manner that it can rotate around the axis of the tool bit, and
an angular positioning device that is disposed on a tip end side of the tool body and serves to fix a position of the tool bit around the axis with respect to the tool body, wherein the angular positioning device includes:
a first locking member that is disposed between the tool body and the tool holder in a direction transverse to the axial direction of the tool bit, and connected to the tool body in such a manner that the first locking member cannot rotate around the axis of the tool bit with respect to the tool body and can rotate around the axis of the tool bit with respect to the tool holder, and
a second locking member that is disposed opposite to the first locking member in the axial direction of the tool bit, connected to the tool holder in such a manner that it cannot rotate around the axis of the tool bit while being allowed to move in the axial direction of the tool bit with respect to the tool holder, and can be connected to or disconnected from the first locking member according to the movement of the second locking member in the axial direction of the tool bit, in such a manner that it cannot rotate around the axis of the tool bit with respect to the first locking member,
wherein one end of the first locking member in the axial direction of the tool bit extends into the housing space of the tool body and is connected to the tool body within the housing space.

5 more elements

An impact tool performing a predetermined hammering operation on a workpiece by a striking movement of a tool bit in an axial direction of the tool bit, comprising:

a tool body,
a striker that linearly moves forward in order to strike the tool bit,
an intermediate element that transmits a striking force of the striker to the tool bit,
a first receiving portion that contacts the striker when the striker further moves forward beyond a predetermined striking position in order to strike the intermediate element,
a second receiving portion that contacts the intermediate element when the striker moves forward beyond the striking position and strikes and moves the intermediate element forward,
a first elastic element that is held in contact with the first receiving portion and elastically deforms by an impact which is caused by contact between the striker and the first receiving portion and transmitted to the first elastic element, and
a second elastic element that is prevented from moving forward by the tool body or by a member on the tool body side which is prevented from moving forward by the tool body, and is held in contact with the first and second receiving portions, and elastically deforms by an impact which is caused by contact of the striker with the first receiving portion and transmitted from the first receiving portion and by an impact which is caused by contact of the intermediate element with the second receiving portion and transmitted from the second receiving portion, wherein:
the first receiving portion and the second receiving portion are disposed side by side in contact with the second elastic element.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/382,536Filed 18 Mar 2009
Priority: JP 2008-07463221 Mar 2008
Published: US 2009/0236110 A124 Sep 2009
Granted: 4 Jan 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

B25D 17/06
Details of, or accessories for, portable power-driven percussive tools: hammer pistons; Anvils ; Guide-sleeves for pistons
B25D 11/005
Portable percussive tools with electromotor or other motor drive: arrangements for adjusting the stroke of the impulse member or for stopping the…
B25D 17/00
Details of, or accessories for, portable power-driven percussive tools
B25D 17/088
Rotating chucks or sockets: with radial movable locking elements co-operating with bit shafts specially adapted therefor