Power tool

Patent metadata

Field	Value
Publication number	US-9969073-B2
Application number	US-201314443038-A
Country	US
Kind code	B2
Filing date	Nov 12, 2013
Priority date	Nov 15, 2012
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A hand-held power tool is disclosed. The tool has a tool receptacle for holding a chiseling tool. A pneumatic percussion mechanism of the hand-held power tool includes a striker, an exciter and a guide tube. The striker is designed to apply impacts in the impact direction to the tool. The exciter is motor-driven. The striker is coupled by an air spring to the reciprocating movement of the exciter. The striker abutting the guide tube is guided along a working axis. During a movement between an impact position and the exciter, the striker is guided with a constant guide length on the guide tube and if the impact position is exceeded in the impact direction, the guide length is reduced. The hand-held power tool is equipped with an inclined guide, which inclines the striker relative to the working axis when the impact position is exceeded.

First claim

The invention claimed is:

1. A hand-held power tool, comprising:
a tool receptacle for holding a chiseling tool; and
a pneumatic percussion mechanism including a striker for applying impacts in an impact direction to the chiseling tool, a motor-driven exciter, wherein the striker is coupled by an air spring to reciprocating movement of the exciter, and a guide tube which the striker abuts when guided along a working axis;
wherein the striker is guided during a movement between an impact position and the exciter with a guide length on the guide tube, wherein the guide length is reduced if the impact position is exceeded in the impact direction, and wherein the striker is guided with a sloped guide after exceeding the impact position and which inclines the striker relative to the working axis;
wherein the sloped guide has a radial inner surface facing the working axis, wherein the striker has a radial surface in contact with the inner surface, and wherein one of the radial inner surface and the radial surface is configured asymmetrically to the working axis;
wherein the radial inner surface or the radial surface has a projection protruding in a radial direction in only one angular direction.

2. The hand-held power tool according to claim 1 further comprising venting ports, wherein the air spring is ventable by the venting ports, and wherein the venting ports are only opened when the striker moves in the impact direction beyond the impact position.

3. The hand-held power tool according to claim 1 , wherein the striker has a piston guided by the guide tube and a push rod forming an impact surface, wherein the sloped guide guides the push rod.

4. The hand-held power tool according to claim 3 , wherein the push rod has a radial surface configured asymmetrically to an axis of the piston.

5. A hand-held power tool, comprising:
a tool receptacle for holding a chiseling tool; and
a pneumatic percussion mechanism including a striker for applying impacts in an impact direction to the chiseling tool and a motor-driven exciter, wherein the striker is coupled by an air spring to reciprocating movement of the exciter;
wherein, if an impact position is exceeded by the striker in the impact direction, the striker is guided with a sloped guide which inclines the striker relative to a working axis;
wherein the sloped guide has a radial inner surface facing the working axis, wherein the striker has a radial surface in contact with the inner surface, and wherein one of the radial inner surface and the radial surface is configured asymmetrically to the working axis;
wherein the radial inner surface or the radial surface has a projection protruding in a radial direction in only one angular direction.

Assignees

• Hilti Ag

Inventors

• Ontl Rainer
• Cehajic Damir
• Dieing Christoph
• Rehekampff Christian

Classifications

• B25D2217/0019

  Guide-sleeves · CPC title

• B25D17/06 Primary

  Hammer pistons; Anvils {; Guide-sleeves for pistons} · CPC title

• B25D2250/191

  Ram catchers for stopping the ram when entering idling mode · CPC title

• B25D2217/0023

  Pistons · CPC title

• B25D11/005

  Arrangements for adjusting the stroke of the impulse member or for stopping the impact action when the tool is lifted from the working surface · CPC title