Fastener driving tool
AssigneeHitachi Koki Co., Ltd.
InventorsYukihiro Shima, Hideyuki Tanimoto, Hiroyuki Oda, Yoshihiro Nakano, Takashi Ueda
Life of this patent
Estimating the term…
Abstract
When the plunger is a game moved to a prescribed position Ph of an initial state on the upper dead point side by the drive force of the motor after the plunger is moved to the lower dead point side, the controller of a spring driven-type fastener driving tool reduces the rotational speed of the motor to a prescribed value or less based on the detection signal of the operation detection switch and then stops the slowed down motor. In order to achieve this, the plunger is stopped at a stop position of an initial state that is as close as possible to an upper dead point side drive start position and is subjected to a strong compression force by the drive spring.
Claims12
A fastener driving tool comprising:
- a motor;
- a DC power supply that supplies electrical power to the motor;
- a magazine that supplies fasteners to a nose;
- a plunger that is driven by the motor to move between an upper dead point and a lower dead point;
- a blade connected to the plunger for driving the fasteners supplied to the nose;
- a drive spring that urges the plunger downwards, and that is capable of being compressed upwards;
- a spring compression drive unit that moves the plunger in a compression direction of the drive spring using a drive force of the motor, and that moves the plunger downwards by releasing the compressed spring;
- a first operation switch that detects a first user operation;
- a second operation switch that detects a second user operation;
- an operation detection sensor that detects a drive state of the spring compression drive unit to produce a detection signal;
- and
- a controller that controls starting, stopping, and rotational speed of the motor based on detection signals from the first operation switch, the second operation switch, and the operation detection sensor,
- the controller including means for providing a pulse width modulation signal to the motor to reduce the rotational speed of the motor based on the detection signal which is output from the operation detection sensor when the operation detection sensor detects that the plunger is moved again to an initial position close to the upper dead point by the drive force of the motor after the plunger is moved to the lower dead point.
A fastener driving tool comprising:
- a motor;
- a power supply that supplies electrical power to the motor;
- a magazine that supplies fasteners to a nose;
- a plunger that is driven by the motor to move between an upper dead point and a lower dead point;
- a blade connected to the plunger for driving the fasteners supplied to the nose;
- a drive spring that urges the plunger downwards, and that is capable of being compressed upwards;
- a spring compression drive unit that moves the plunger in a compression direction of the drive spring using the motor, and that moves the plunger downwards by releasing the compressed drive spring;
- an operation switch that detects a user operation;
- an operation detection sensor that detects a drive state of the spring compression drive unit;
- a driving detection switch that detects driving of the fastener;
- and
- a controller that controls the motor based on detection signals from the operation switch, the operation detection sensor, and the drive detection switch,
- wherein the controller supplies a pulse width modulation signal to the motor to reduce the speed of the motor when the operation detection sensor detects that the plunger is moved to a first prescribed position by the spring compression drive unit after detection of driving of the fastener by the drive detection switch, and
- the controller stops the supply of electrical power from the power supply to the motor when the operation detection sensor detects that the plunger is moved to a second prescribed position above the first prescribed position by the spring compression drive unit during reduced speed of the motor.
Dependencies are inferred from the claim text.