Rotary hammer

Patent metadata

Field	Value
Publication number	US-10399216-B2
Application number	US-201414560701-A
Country	US
Kind code	B2
Filing date	Dec 4, 2014
Priority date	Dec 11, 2013
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A hammer/drill includes a housing, a motor with armature shaft, a spindle rotatably mounted about a longitudinal axis in the housing, a tool holder rotatingly driven by the motor about the longitudinal axis, a hammer mechanism for generating impacts acting on the tool holder, a drive shaft coupleable with the armature shaft, and a switching arrangement to switch between drilling, hammer drilling, and hammering modes. The switching arrangement comprises a selector and coupling part axially displaceable on the drive shaft between lower and upper positions, coupling and decoupling the drive shaft to the armature shaft respectively. The coupling part includes a sleeve comprising a flange, and the selector comprises a fork for engaging a lower part of the flange. A protuberance engages a drive member of the selector to pivot the selector when the spindle is rotated, engaging over only a portion of the rotational movement of the spindle.

First claim

The invention claimed is:

1. A rotary hammer comprising:
a hammer housing;
a motor having an armature shaft;
a hammer spindle rotatably mounted about a longitudinal axis in the hammer housing;
a switching element disposed on or at least partially outside the hammer housing;
a tool holder provided at an end of the hammer housing and being rotatingly driven by the motor about the longitudinal axis of the hammer spindle;
a hammer mechanism provided in the hammer housing for generating impact on a bit received in the tool holder, the hammer mechanism having a drive shaft selectively coupled with the armature shaft; and
a spindle rotatable by the switching element about a rotational axis, the spindle including a protuberance; and
a switching arrangement arranged to activate the hammer mechanism, the switching arrangement comprises:
a coupling part having a sleeve-shaped body axially displaceable on the drive shaft of the hammer mechanism between a first position in which the drive shaft is coupled to the armature shaft to activate the hammer mechanism and a second position in which the drive shaft is decoupled from the armature shaft to deactivate the hammer mechanism, and
a selector for displacing the coupling part between the first position and the second position, the selector comprising: a main body being pivotably mounted on the spindle adjacent the protuberance so that it is can pivot on the spindle about the rotational axis of the spindle, a drive member extending from the main body in the axial direction of the spindle radially aligned with the protuberance and in selective engagement with the protuberance to pivot the selector about the rotational axis of the spindle when the spindle is rotated, and a fork extending peripherally from the main body and engaging the coupling part to axially displace the coupling part between the first position and the second position as the selector is pivoted about the rotational axis of the spindle,

wherein, within a first range of rotational movement of the switching element, the protuberance does not engage the drive member and thus the selector does not pivot on the spindle to axially displace the coupling part, and within a second range of rotational movement of the switching element, the protuberance engages the drive member to pivot the selector on the spindle and thus axially displace the coupling part, and
wherein the rotational axis of the spindle does not intersect the sleeve-shaped body of the coupling part.

2. The rotary hammer of claim 1 , wherein the coupling part is non-rotatably mounted on the drive shaft.

3. The rotary hammer of claim 1 , wherein the coupling part comprises an annular flange.

4. The rotary hammer of claim 3 , wherein the fork of the selector comprises two arms arranged to engage the annular flange.

5. The rotary hammer of claim 1 , wherein the selector is pivotable around an internal axis that is substantially perpendicular to the longitudinal axis of the hammer spindle.

6. The rotary hammer of claim 1 , further comprising a drive sleeve arranged rotatably on the hammer spindle and selectively coupled to the hammer spindle, and a coupling sleeve rotationally fixed but axially displaceable on the hammer spindle, wherein the coupling sleeve couples the drive sleeve to the hammer spindle in a first axial position and decouples the drive sleeve from the hammer spindle in a second axial position.

7. The rotary hammer of claim 6 , further comprising a cam portion on the spindle and a linear slider part movable in parallel to the longitudinal axis of the hammer spindle, the cam portion acting on the coupling sleeve via the linear slider part to move the coupling sleeve between the first axial position and the second axial position.

8. The rotary hammer of claim 7 , wherein the protuberance is arranged adjacent the cam portion.

9. The rotary hammer of claim 1 , wherein the protuberance is formed on an end of the spindle.

10. The rotary hammer of claim 1 , wherein the protuberance and the drive member are angularly offset from each other such that they only engage each other over a portion of the rotational movement of the spindle.

11. The rotary hammer of claim 1 , wherein within a first angular range of the rotational movement of the spindle, the protuberance does not engage the drive member and the rotational movement of the spindle does not drive the selector, and within a second angular range of the rotational movement of the spindle, the protuberance engages the drive member and the rotational movement of the spindle pivotably drives the selector to move the coupling part.

12. The rotary hammer of claim 1 , wherein the armature shaft of the motor, the longitudinal axis of the hammer spindle, and the rotational axis of the spindle are all substantially perpendicular to one another.

13. The rotary hammer of claim 1 , wherein the drive member is positioned outside an outer circumference of the spindle.

Assignees

• Black & Decker Inc

Inventors

• Lauterwald Martin
• Roberts Ana-Maria

Classifications

• B25D2216/0015

  Tools having a percussion-only mode · CPC title

• B25D2211/003

  Crossed drill and motor spindles · CPC title

• B25D16/006 Primary

  Mode changers; Mechanisms connected thereto · CPC title

• B25D2216/0038

  Tools having a rotation-only mode · CPC title

• B25D2216/0023

  Tools having a percussion-and-rotation mode · CPC title