Hand-held power tool and control method
AssigneeHilti Aktiengesellschaft
InventorEric Mascall
Life of this patent
Estimating the term…
Abstract
A control method for a hand-held power tool includes measuring a temperature of an electric motor, opening a switchable clutch if the temperature exceeds a first threshold value, and energizing the electric motor when the clutch is open until the temperature falls below a second threshold value. In an embodiment, the electric motor is switched to a current-free mode, i.e., switched off, if the temperature falls below the second threshold value. The second threshold value is preferably less than the first threshold value.
Claims6
A hand-held power tool, comprising:
- a tool holder for holding a tool on a work shaft;
- an electric motor, wherein the electric motor drives the tool holder via a switchable clutch disposed in a drive train between the tool holder and the electric motor;
- a temperature sensor, wherein a temperature of the electric motor is measurable by the temperature sensor;
- a fan wheel coupled to the electric motor;
- and
- a motor controller, wherein the motor controller triggers an opening of the switchable clutch when a first measured temperature of the electric motor exceeds a first threshold value, energizes the electric motor when the switchable clutch is open until a second measured temperature of the electric motor falls below a second threshold, and switches the electric motor to a non-powered state when the second measured temperature falls below the second threshold.
A control method for a hand-held power tool wherein the hand-held power tool comprises:
- a tool holder for holding a tool on a work shaft;
- an electric motor, wherein the electric motor drives the tool holder via a switchable clutch disposed in a drive train between the tool holder and the electric motor;
- a temperature sensor, wherein a temperature of the electric motor is measurable by the temperature sensor;
- and
- a fan wheel coupled to the electric motor;
- and comprising the steps of:
- measuring the temperature of the electric motor;
- opening the switchable clutch when a first measured temperature of the electric motor exceeds a first threshold;
- energizing the electric motor when the switchable clutch is open until a second measured temperature of the electric motor falls below a second threshold;
- and
- switching the electric motor to a non-powered state when the second measured temperature falls below the second threshold.
A control method for a hand-held power tool wherein the hand-held power tool comprises:
- a tool holder for holding a tool on a work shaft;
- an electric motor, wherein the electric motor drives the tool holder via a switchable clutch disposed in a drive train between the tool holder and the electric motor;
- a temperature sensor, wherein a temperature of the electric motor is measurable by the temperature sensor;
- and
- a fan wheel coupled to the electric motor;
- and comprising the steps of:
- measuring the temperature of the electric motor;
- opening the switchable clutch when a first measured temperature of the electric motor exceeds a first threshold;
- energizing the electric motor when the switchable clutch is open until a second measured temperature of the electric motor falls below a second threshold;
- and
- detecting a release of a power switch by a user of the hand-held power tool and, in response to the release, deenergizing the electric motor only when a measured temperature of the electric motor is less than the first threshold.
Dependencies are inferred from the claim text.