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US 12,728,491 B2Granted
Drop detection in power tools
AssigneeMilwaukee Electric Tool Corporation
InventorsJoseph G. Bloomfield, Arik A. Miller, Daniel J. Tomcheck
Life of this patent
Estimating the term…
Abstract
A power tool comprising a power tool housing and a motor within the power tool housing. The motor including a rotor and a stator, the rotor coupled to a motor shaft to produce a rotational output. The power tool further includes a sensor within the power tool housing, the sensor configured to sense a free fall of the power tool, generate an output signal related to the sensed free fall. The power tool further includes a controller including a processor and a memory, the controller configured to receive the output signal from the sensor, detect the free fall of the power tool based on the output signal from the sensor, and brake the motor when the free fall of the power tool is detected.
Claims16
A power tool comprising:
- a power tool housing;
- a motor within the power tool housing, the motor including a rotor and a stator, the rotor coupled to a motor shaft to produce a rotational output;
- at least one semiconductor switch;
- a plurality of motor coils;
- an inertial measurement unit (IMU) within the power tool housing, the IMU configured to:
- sense a free fall of the power tool, and
- generate an output signal related to the sensed free fall;
- and
- a controller including a processor and a memory, the controller configured to:
- receive the output signal from the IMU,
- detect the free fall of the power tool based on the output signal from the IMU,
- enable, in response to detecting the free fall of the power tool, the at least one semiconductor switch and shunt the plurality of motor coils to ground, and
- disable, in response to detecting the free fall of the power tool, the motor without collecting data related to a timing at which the power tool hits an external object or a distance that the power tool has fallen.
10 more elements
A power tool comprising:
- a power tool housing;
- a motor within the power tool housing, the motor including a rotor and a stator, the rotor coupled to a motor shaft to produce a rotational output;
- an inertial measurement unit (IMU) within the power tool housing, the IMU configured to:
- sense a free fall of the power tool, and
- generate an output signal related to the sensed free fall;
- and
- a controller including a processor and a memory, the controller configured to:
- receive the output signal from the IMU,
- detect the free fall of the power tool based on the output signal from the IMU.
- disable, in response to detecting the free fall of the power tool, the motor without collecting data related to a timing at which the power tool hits an external object or a distance that the power tool has fallen,
- detect when a trigger of the power tool is released;
- and
- brake the motor when a motor voltage value is below a predetermined threshold.
10 more elements
A power tool comprising:
- a power tool housing;
- a motor within the power tool housing, the motor including a rotor and a stator, the rotor coupled to a motor shaft to produce a rotational output;
- an inertial measurement unit (IMU) within the power tool housing, the IMU configured to:
- sense a free fall of the power tool, and
- generate an output signal related to the sensed free fall;
- and
- a controller including a processor and a memory, the controller configured to:
- receive the output signal from the IMU,
- detect the free fall of the power tool based on the output signal from the IMU,
- disable, in response to detecting the free fall of the power tool, the motor without collecting data related to a timing at which the power tool hits an external object or a distance that the power tool has fallen,
- disconnect power to the motor with a power switch to brake the motor when the free fall of the power tool is detected;
- and
- turn on a brake resistor to dissipate energy from the motor.
10 more elements
A method for controlling a power tool during a free fall of the power tool, the power tool including at least one semiconductor switch and a plurality of motor coils, the method comprising:
- sensing, using an inertial measurement unit (IMU), the free fall of the power tool;
- generating, using the IMU, an output signal related to the free fall of the power tool;
- detecting the free fall of the power tool based on the output signal from the IMU;
- enabling, after detecting the free fall of the power tool, the at least one semiconductor switch of the power tool;
- shunting the plurality of motor coils to ground;
- and
- disabling, in response to detecting the free fall of the power tool, a motor without collecting data related to a timing at which the power tool hits an external object or a distance that the power tool has fallen.
4 more elements
A method for controlling a power tool during a free fall of the power tool, the method comprising:
- sensing, using an inertial measurement unit (IMU), the free fall of the power tool;
- generating, using the IMU, an output signal related to the free fall of the power tool;
- detecting the free fall of the power tool based on the output signal from the IMU;
- disabling, in response to detecting the free fall of the power tool, a motor without collecting data related to a timing at which the power tool hits an external object or a distance that the power tool has fallen;
- detecting when a trigger of the power tool is released;
- and
- braking the motor when a motor voltage value is below a predetermined threshold.
4 more elements
A method for controlling a power tool during a free fall of the power tool, the method comprising:
- sensing, using an inertial measurement unit (IMU), the free fall of the power tool;
- generating, using the IMU, an output signal related to the free fall of the power tool;
- detecting the free fall of the power tool based on the output signal from the IMU;
- disabling, in response to detecting the free fall of the power tool, a motor without collecting data related to a timing at which the power tool hits an external object or a distance that the power tool has fallen;
- disconnecting power to the motor with a power switch to brake the motor when the free fall of the power tool is detected;
- and
- turning on a brake resistor to dissipate energy from the motor.
4 more elements
A power tool comprising:
- a power tool housing;
- a motor within the power tool housing, the motor including a rotor and a stator, the rotor coupled to a motor shaft to produce a rotational output;
- an inertial measurement unit (IMU) within the power tool housing, the IMU configured to generate an output signal related to a free fall of the power tool;
- and
- a controller including a processor and a memory, the controller configured to:
- receive the output signal from the IMU,
- determine an amount of time that the power tool has been in free fall,
- compare the amount of time that the power tool has been in free fall to a predetermined time threshold, and
- disable, without collecting data related to a timing at which the power tool hits an external object or a distance that the power tool has fallen, the motor when the amount of time that the power tool has been in free fall is equal to or greater than the predetermined time threshold.
6 more elements
Dependencies are inferred from the claim text.