Power tool having hammer mechanism

Patent metadata

Field	Value
Publication number	US-11318596-B2
Application number	US-202017072444-A
Country	US
Kind code	B2
Filing date	Oct 16, 2020
Priority date	Oct 21, 2019
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

A power tool includes a motor having a motor shaft, a first intermediate shaft, and a second intermediate shaft extending in parallel to the first intermediate shaft. An output shaft removably holds a tool accessory and has a driving axis extending in parallel to the first and second intermediate shafts. A motion-converting mechanism converts rotation of the first intermediate shaft to linearly hammer the tool accessory. A rotation-transmitting mechanism transmits rotation of the second intermediate shaft to rotate the output shaft. A rotational axis of the motor shaft intersects, or is skewed relative to, the driving axis. A pair of first gears, e.g., bevel gears, operably couples the motor shaft to a first one of the first and second intermediate shafts. A pair of second gears operably couples the first one of the first and second intermediate shafts to a second one of the first and second intermediate shafts.

First claim

What is claimed is:

1. A power tool, comprising:
a final output shaft configured to removably hold a tool accessory and to be rotatable around a driving axis;
a motor having a motor shaft extending in a direction intersecting the driving axis;
a first intermediate shaft extending in parallel to the driving axis;
a first driving mechanism including a motion-converting mechanism disposed on and/or around the first intermediate shaft and configured to convert rotation of the first intermediate shaft into linear reciprocating motion to hammer the tool accessory along the driving axis;
a second intermediate shaft extending in parallel to the driving axis; and
a second driving mechanism configured to transmit rotation of the second intermediate shaft to the final output shaft to rotationally drive the tool accessory around the driving axis,
wherein:
the motor shaft is configured to rotate the first intermediate shaft via first and second bevel gears, the first bevel gear being disposed on the first intermediate shaft adjacent to a first bearing that rotatably supports a first end portion of the first intermediate shaft, and
the first intermediate shaft is configured to rotate the second intermediate shaft via first and second gears, the first gear being disposed on the first intermediate shaft between the first bevel gear and the motion-converting mechanism.

2. The power tool as defined in claim 1 , further comprising a torque limiter disposed on and/or around the second intermediate shaft and configured to interrupt transmission of power in response to torque acting on the second intermediate shaft exceeding a threshold.

3. The power tool as defined in claim 2 , wherein the torque limiter includes:
a drive-side cam;
a driven-side cam configured to engage with the drive-side cam; and
a ball rollably disposed within a track extending in an axial direction of the second intermediate shaft between an inner periphery of one of the drive-side cam and the driven-side cam and an outer periphery of the second intermediate shaft,
wherein the one of the drive-side cam and the driven-side cam is configured to, in response to the torque acting on the second intermediate shaft exceeding the threshold, move in the axial direction away from the other of the drive-side cam and the driven-side cam to be disengaged therefrom, while being guided by the ball.

4. The power tool as defined in claim 3 , wherein the torque limiter includes a biasing member configured to bias the drive-side cam toward the driven-side cam or vice versa.

5. The power tool as defined in claim 1 , wherein a rotation axis of the motor shaft and a rotation axis of the first intermediate shaft define a first plane.

6. The power tool as defined in claim 5 , wherein the driving axis also extends in the first plane.

7. The power tool as defined in claim 6 , wherein:
an extension direction of the driving axis is defined as a front-rear direction of the power tool,
an up-down direction is orthogonal to the driving axis and generally corresponds to an extension direction of the motor shaft,
a left-right direction is orthogonal to the front-rear direction and to the up-down direction,
in the front-rear direction, the tool accessory is disposed on a front side of the power tool,
in the up-down direction, the motor is located on a lower side of the driving axis, and
when viewed from a rear side of the power tool in the front-rear direction, a rotation axis of the second intermediate shaft is located leftward of the first plane in the left-right direction.

8. The power tool as defined in claim 1 , further comprising:
a first clutch mechanism provided on and/or around the first intermediate shaft and configured to enable and disable power transmission for linearly driving the tool accessory, and
a second clutch mechanism provided on and/or around the second intermediate shaft and configured to enable and disable power transmission for rotationally driving the tool accessory.

9. The power tool as defined in claim 8 , further comprising:
a manually operable member configured to selectively change an action mode of the power tool,
wherein the first and second clutch mechanisms are each configured to be switched between a power-transmitting state and a power-interrupting state in response to manual operation of the manually operable member.

10. The power tool as defined in claim 9 , further comprising:
a first switching member configured to move in response to manual operation of the manually operable member and thereby switch the first clutch mechanism between the power-transmitting state and the power-interrupting state, and
a second switching member configured to move in response to manual operation of the manually operable member and thereby switch the second clutch mechanism between the power-transmitting state and the power-interrupting state.

11. The power tool as defined in claim 10 , wherein the manually operable member includes:
a first contact part configured to come into contact with the first switching member and thereby move the first switching member, and
a second contact part configured to come into contact with the second switching member and thereby move the second switching member.

12. The power tool as defined in claim 10 , wherein an integral support member supports the first switching member and the second switching member so as to be movable relative to the integral support member.

13. The power tool as defined in claim 1 , wherein:
a first portion of the first intermediate shaft extends between the first gear and a second bearing that rotatably supports a second end portion of the first intermediate shaft,
a second portion of the second intermediate shaft extends between the second gear and a bearing rotatable supporting a forwardmost end of the second intermediate shaft, and
the first portion at least partially overlaps the second portion in a direction perpendicular to the driving axis.

14. The power tool as defined in claim 13 , wherein:
the motion-converting mechanism is disposed on and/or around a segment of the first portion of the first intermediate shaft that overlaps the second portion of the second intermediate shaft in the direction perpendicular to the driving axis.

15. The power tool as defined in claim 1 , wherein the first gear is disposed between the first bearing and a second bearing that rotatably supports a second end portion of the first intermediate shaft.

16. A power tool, comprising:
a final output shaft configured to removably hold a tool accessory and to be rotatable around a driving axis;
a motor having a motor shaft that extends in a direction intersecting the driving axis;
a first intermediate shaft extending in parallel to the driving axis;
a second intermediate shaft extending in parallel to the driving axis and to the first intermediate shaft;
a motion-converting mechanism configured to convert rotation of the first intermediate shaft into linear reciprocating motion to hammer the tool accessory along the driving axis;
a rotation-transmitting mechanism configured to transmit rotation of the second intermediate shaft to the final output shaft to rotationally drive the tool accessory around the driving axis;
a driving bevel gear disposed on the motor shaft;
a driven bevel gear disposed on the first intermediate shaft adjacent to a bearing that rotatably supports one end portion of the first intermediate shaft, the driven bevel gear meshing with the driving bevel gear disposed on the motor shaft;
a driving gear disposed on the first intermediate shaft betwee

Assignees

• Makita Corp

Inventors

• Yoshikane Kiyonobu
• Takano Yusuke

Classifications

• B25D2217/0073

  Arrangements for damping of the reaction force · CPC title

• B25D16/006 Primary

  Mode changers; Mechanisms connected thereto · CPC title

• B25D16/003

  Clutches specially adapted therefor · CPC title

• B25D17/24

  Damping the reaction force {(resiliently mounted handles B25D17/043; dampers in connections of hammers to backhoes E02F3/966)} · CPC title

• B25D2216/0015

  Tools having a percussion-only mode · CPC title