Chainsaw

Patent metadata

Field	Value
Publication number	US-10695943-B2
Application number	US-201615742565-A
Country	US
Kind code	B2
Filing date	Jul 7, 2016
Priority date	Jul 13, 2015
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

A chainsaw includes a handle with a handgrip; an electric motor for endlessly moving a saw chain; a control unit for controlling rotation of the motor; and a main power switch switchable between an ON state and an OFF state. The handgrip is provided with a gripping detection device for detecting whether the handgrip is gripped by the worker, and the chainsaw is configured to, when the control unit is manipulated to deactivate the electric motor in a state in which the gripping detection device detects that the handgrip is gripped, maintain the main power switch in the ON state, and to, when the control unit is manipulated to deactivate the electric motor in a state in which the gripping detection device detects that the handgrip is not gripped, switch the main power switch to the OFF state.

First claim

The invention claimed is:

1. A chainsaw comprising:
a housing;
at least one handle coupled to the housing, the at least one handle including a handgrip to be gripped by a worker using the chainsaw;
a guide bar coupled to the housing in such a manner as to protrude forwardly from the housing, the guide bar formed in an elongate plate shape having an outer periphery;
a saw chain slidably provided around the outer periphery of the guide bar in such a manner as to be endlessly moved along the outer periphery;
an electric motor provided inside the housing and operable to endlessly move the saw chain;
an electric power supply;
a main power switch provided electrically between the electric power supply and the electric motor, the main power switch being switchable between an ON state for enabling electric power feeding from the electric power supply to the electric motor, and an OFF state for disabling the electric power feeding;
a trigger for controlling the electric power feeding from the electric power supply to the electric motor in a state in which the main power switch is switched to the ON state, to thereby control rotation of the electric motor;
at least one detector provided in the handgrip and operable to detect whether or not the handgrip is gripped by the worker; and
an interlocking device associated with the electric motor, the main power switch, the trigger and the detector, the interlocking device being configured to, when the trigger is manipulated to stop the rotation of the electric motor in a state in which the detector detects that the handgrip is gripped by the worker, maintain the ON state of the main power switch, and to, when the trigger is manipulated to stop the rotation of the electric motor in a state in which the detector detects that the handgrip is not gripped by the worker, switch the ON state of the main power switch to the OFF state.

2. The chainsaw as recited in claim 1 , wherein the at least one handle comprises a first handle and a second handle, and the at least one detector comprises a first detector and a second detector;
the first handle having a first handgrip to be gripped by one hand of the worker using the chainsaw,
the second handle having a second handgrip to be gripped by the other hand of the worker using the chainsaw,
the first handgrip being provided with the first detector operable to detect whether the first handgrip is gripped by the worker,
the second handgrip being provided with the second detector operable to detect whether or not the second handgrip is gripped by the worker, and
the interlocking device is configured to, when the trigger is manipulated to stop the rotation of the electric motor in a state in which each of the first detector and the second detector detects that a corresponding one of the first handgrip and the second handgrip is gripped by the worker, maintain the main power switch in the ON state, and to, when the trigger is manipulated to stop the rotation of the electric motor in a state in which at least one of the first detector and the second detector detects that a corresponding one of the first handgrip and the second handgrip is not gripped by the worker, switch the main power switch to the OFF state.

3. The chainsaw as recited in claim 2 , wherein the first detector or the second detector comprises:
a gripping detection member configured to be protruded from the handgrip to take an ungripped position when the handgrip is not gripped by the worker, and to be retracted inside the handgrip to take a gripped position when the handgrip is gripped by the worker; and
a position detector operable to detect whether the gripping detection member is located at the ungripped position or at the gripped position,
wherein the first detector or the second detector is configured to detect whether or not the handgrip is gripped by the worker, depending on whether the position detector detects that the gripping detection member is located at the gripped position or that the gripping detection member is located at the ungripped position.

4. The chainsaw as recited in claim 2 , wherein the first detector or the second detector comprises
a transmitter provided in one of the handgrip and a worn article worn on a hand of the worker, and
a receiver provided in the other of the handgrip and the worn article, the receiver being capable of receiving a signal transmitted from the transmitter, when the worker grips the handgrip, and wherein the first detector or the second detector is configured to detect whether or not the handgrip is gripped by the worker, depending on whether or not the receiver has received the signal transmitted from the transmitter.

5. The chainsaw as recited in claim 2 , wherein the first detector or the second detector comprises a light detector provided in the handgrip and operable to detect light from surroundings, the light detector being operable to detect whether or not the light detector is covered by a hand of the worker to thereby cause light from the surroundings to be blocked, and wherein the first detector or the second detector is configured to detect whether or not the handgrip is gripped by the worker, depending on whether or not light from the surroundings has been blocked.

6. The chainsaw as recited in claim 2 , wherein the first detector or the second detector comprises a pressure-sensitive detector provided in the handgrip and operable to detect a change in pressure applied to the handgrip when the handgrip is gripped by the worker, and wherein the first detector or the second detector is configured to detect whether or not the handgrip is gripped by the worker, depending on whether or not the pressure-sensitive detector has detected the pressure change.

7. The chainsaw as recited in claim 1 , wherein the detector comprises:
a gripping detection member configured to be protruded from the handgrip to take an ungripped position when the handgrip is not gripped by the worker, and to be retracted inside the handgrip to take a gripped position when the handgrip is gripped by the worker; and
a position detector operable to detect whether the gripping detection member is located at the ungripped position or at the gripped position,
wherein the detector is configured to detect whether or not the handgrip is gripped by the worker, depending on whether the position detector detects that the gripping detection member is located at the gripped position or that the gripping detection member is located at the ungripped position.

8. The chainsaw as recited in claim 1 , wherein the detector comprises:
a transmitter provided in one of the handgrip and a worn article worn on a hand of the worker, and
a receiver provided in the other of the handgrip and the worn article, the receiver being capable of receiving a signal transmitted from the transmitter, when the worker grips the handgrip, and wherein the detector is configured to detect whether or not the handgrip is gripped by the worker, depending on whether or not the receiver has received the signal transmitted from the transmitter.

9. The chainsaw as recited in claim 1 , wherein the detector comprises a light detector provided in the handgrip and operable to detect light from surroundings, the light detector being operable to detect whether or not the light detector is covered by a hand of the worker to thereby cause light from the surroundings to be blocked, and wherein the detector is configured to detect whether or not the handgrip is gripped by the worker, depending on whether or not light from the surroundings has been blocked.

10. The chainsaw as recited in claim 1 , wherein the detector comprises a pressure-sensitive detector provided in the handgrip and operable t

Assignees

• Makita Corp

Inventors

• Kachi Hideki
• Haneda Koji
• NAKAMURA Tsunahisa

Classifications

• F16P3/20

  for electric control systems · CPC title

• B27G19/06 Primary

  for band or strap saws · CPC title

• B27B17/0008

  Means for carrying the chain saw, e.g. handles (B27B17/0033 takes precedence) · CPC title

• B27B17/02

  Chain saws equipped with guide bar (B27B17/06 takes precedence) · CPC title

• B27B17/08

  Drives or gearings; Devices for swivelling or tilting the chain saw · CPC title