Variable speed switch and electric power tool with the variable speed switch mounted thereto

Patent metadata

Field	Value
Publication number	US-9444307-B2
Application number	US-201414152299-A
Country	US
Kind code	B2
Filing date	Jan 10, 2014
Priority date	Sep 17, 2010
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A variable speed switch includes a switch main body portion which is accommodated in a housing of an electric power tool and mounted to the housing so as to be capable of relative movement, and a load sensor which is provided in the switch main body portion and capable of outputting an electric signal in proportion to the amount of distortion caused by a pressing force. The switch operating portion is mounted on the surface of the housing so as to be capable of relative displacement with respect to the housing and transmits a pressing force applied to the switch operating portion to the load sensor, with the maximum displacement amount of the switch operating portion being set to equal to or less than 5 mm.

First claim

We claim:

1. An electric power tool comprising:
an electric motor;
a housing;
a switch operating portion;
a variable speed switch that outputs an electric signal for increasing or decreasing the amount of electric power supplied to the motor in proportion to a displacement amount of the switch operating portion; and
a control circuit that inputs the electric signal and adjusts the electric power supplied to the motor; wherein:
the variable speed switch further comprises:
a switch main body portion accommodated in the housing and mounted to the housing such that the switch main body portion is not relatively moved with respect to the housing; and
a load sensor connected to the switch main body portion and capable of outputting an electric signal in proportion to the amount of distortion caused by a pressing force, and
the switch operating portion is configured to cover an opening provided in the housing and be mounted on a surface of the housing so as to be capable of relative displacement with respect to the housing and transmits the pressing force applied to the switch operating portion to the load sensor, with the maximum amount of the relative displacement of the switch operating portion being set to equal to or less than 5 mm, and
the switch operating portion is formed of an elastic material and waterproofly seals the opening.

2. The electric power tool according to claim 1 , wherein:
the switch operating portion includes an operating portion main body disposed in the outer side of the housing, a shaft portion passed through the opening, and a load transmission portion transmitting a pressing force to the load sensor inside the housing; and
the shaft portion is formed of the elastic material and waterproofly seals the opening of the housing by the shaft portion being attached firmly around a circumference of the opening of the housing.

3. The electric power tool according to claim 2 , wherein the operating portion main body, the shaft portion, and the load transmission portion are integrally formed of the elastic material.

4. The electric power tool according to claim 1 , further comprising:
a planetary gear mechanism;
a spindle;
a striking force generation mechanism including a hammer and a compressing spring;
a bearing; and
an anvil, wherein:
the anvil is supported so as to be rotatable around an axis by the bearing; and
the motor, the planetary gear mechanism, the spindle, the striking force generation mechanism, and the anvil are coaxially arranged in the housing.

5. The electric power tool according to claim 1 , wherein:
the housing includes a tubular housing main body and a handle portion radially protruding from a side surface of the housing main body; and
the switch operating portion is attached to a proximal end portion of the handle portion.

6. The electric power tool according to claim 1 , wherein:
the housing includes a tubular housing main body and a handle portion radially protruding from a side surface of the housing main body: and
the switch operating portion is attached to a rear end surface of the housing main body.

7. The electric power tool according to claim 1 , wherein:
the housing includes a tubular housing main body and a handle portion radially protruding from a side surface of the housing main body; and
the switch operating portion is attached to a side surface of the housing main body and/or a side surface of the handle portion.

8. The electric power tool according to claim 1 , wherein a plurality of the switch operating portions are attached to the housing.

9. The electric power tool according to claim 8 , wherein the plurality of the switch operating portions are attached to the handle portion.

10. An electric power tool comprising:
an electric motor;
a housing;
a switch operating portion; and
a switch that is operated by a displacement of the switch operating portion;

wherein,
the switch operating portion is configured to cover an opening provided in the housing and be mounted on a surface of the housing so as to be capable of relative displacement with respect to the housing, with the maximum amount of the relative displacement of the switch operating portion being set to equal to or less than 5 mm,
the switch operating portion is formed of an elastic material and waterproofly seals the opening,
the switch comprises:
a switch main body portion accommodated inside the opening provided in the housing and mounted to the housing such that the switch main body portion is not relatively moved with respect to the housing; and
a switch element provided in the switch main body portion and operated by the displacement of the switch operating portion,

the switch operating portion includes an operating portion main body disposed in the outer side of the housing, a shaft portion passed through the opening, and a transmission portion transmitting the displacement of the switch operating portion to the switch element inside the housing; and
the shaft portion is formed of the elastic material and waterproofly seals the opening of the housing by the shaft portion being attached firmly around a circumference of the opening of the housing.

11. The electric power tool according to claim 10 , wherein the switch element is an on/off switch.

12. The electric power tool according to claim 10 , wherein:
the switch is a variable speed switch that outputs an electric signal for increasing or decreasing the amount of electric power supplied to the motor in proportion to a displacement amount of the switch operating portion;
the switch element is a load sensor capable of outputting an electric signal in proportion to the amount of distortion caused by a pressing force; and
the electric power tool further comprises a control circuit that inputs the electric signal and adjusts the electric power supplied to the motor.

13. The electric power tool according to claim 12 , wherein the switch operating portion transmits the pressing force applied to the switch operating portion to the load sensor.

Assignees

• Makita Corp

Inventors

• Watanabe Masahiro
• Kusakawa Takuya
• Nagasaka Hidenori

Classifications

• B25F5/001 Primary

  Gearings, speed selectors, clutches or the like specially adapted for rotary tools · CPC title

• H01H9/04

  Dustproof, splashproof, drip-proof, waterproof, or flameproof casings · CPC title

• H01H2009/048

  using a sealing boot, e.g. the casing having separate elastic body surrounding the operating member and hermetically closing the opening for it · CPC title

• B25F5/02

  Construction of casings, bodies or handles {(B25F5/006, B25F5/008 take precedence)} · CPC title

• H02K7/14 Primary

  Structural association with mechanical loads, e.g. with hand-held machine tools or fans (with fan or impeller for cooling the machine H02K9/06) · CPC title