Power tool with force sensing electronic clutch
First Claim
1. A power tool comprising:
- a housing;
a motor disposed in the housing;
a transmission disposed in the housing and coupled to the motor and defining a longitudinal axis;
an output end effector coupled to the transmission;
a control circuit for controlling power delivery from a power source to the motor; and
a force sensing electronic clutch including a force sensor coupled to a substantially stationary element of the transmission to sense a reaction torque transmitted from the end effector to at least a portion of the transmission, the substantially stationary element having one of a projection and a recess that mates with the other of a projection and a recess on the housing so that the force sensor is disposed between and in a common plane with the projection and the recess, the common plane being transverse to the longitudinal axis,wherein the sensor is configured to generate a first electronic signal corresponding to an amount of the reaction torque, andwherein the control circuit compares the first electronic signal with a second electronic signal corresponding to a desired threshold torque value, and initiates a protective operation when a value of the first electronic signal indicates that the reaction torque has exceeded the desired threshold torque value.
2 Assignments
0 Petitions
Accused Products
Abstract
A power tool includes a housing, a motor disposed in the housing, a transmission disposed in the housing and coupled to the motor, an output end effector coupled to the transmission, a control circuit for controlling power delivery from a power source to the motor, and a force sensing electronic clutch including a force sensor coupled to a substantially stationary element of the transmission. The force sensor senses a reaction torque transmitted from the end effector to at least a portion of the transmission. The sensor is configured to generate a first electronic signal corresponding to an amount of the reaction torque. The control circuit compares the first electronic signal with a second electronic signal corresponding to a desired threshold torque value, and initiates a protective operation when a value of the first electronic signal indicates that the reaction torque has exceeded the desired threshold torque value.
67 Citations
22 Claims
-
1. A power tool comprising:
-
a housing; a motor disposed in the housing; a transmission disposed in the housing and coupled to the motor and defining a longitudinal axis; an output end effector coupled to the transmission; a control circuit for controlling power delivery from a power source to the motor; and a force sensing electronic clutch including a force sensor coupled to a substantially stationary element of the transmission to sense a reaction torque transmitted from the end effector to at least a portion of the transmission, the substantially stationary element having one of a projection and a recess that mates with the other of a projection and a recess on the housing so that the force sensor is disposed between and in a common plane with the projection and the recess, the common plane being transverse to the longitudinal axis, wherein the sensor is configured to generate a first electronic signal corresponding to an amount of the reaction torque, and wherein the control circuit compares the first electronic signal with a second electronic signal corresponding to a desired threshold torque value, and initiates a protective operation when a value of the first electronic signal indicates that the reaction torque has exceeded the desired threshold torque value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A power tool comprising:
-
a housing; a motor disposed in the housing; a transmission disposed in the housing and coupled to the motor; an output end effector coupled to the transmission; a control circuit for controlling power delivery from a power source to the motor; a force sensing electronic clutch including a force sensor that senses a reaction torque transmitted from the end effector to at least a portion of the transmission and causes the control circuit to initiate a first protective operation when the sensed reaction torque exceeds a first threshold torque value; and a current sensor that senses an amount current delivered to the motor, wherein the control circuit uses a current signal from the current sensor to automatically re-calibrate the first electronic signal from the force sensor, during a period when the control circuit determines that the current signal by itself is a good indicator of output torque. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. A power tool comprising:
-
a housing; a motor disposed in the housing; a transmission disposed in the housing and coupled to the motor; an output end effector coupled to the transmission; a control circuit for controlling power delivery from a power source to the motor; a force sensing electronic clutch including a force sensor that senses a reaction torque transmitted from the end effector to at least a portion of the transmission and causes the control circuit to initiate a first protective operation when the sensed reaction torque exceeds a first threshold torque value; a current sensing electronic clutch including a current sensor that senses an amount current delivered to the motor, and a controller that causes the controller to initiate a second protective operation when a value from the current sensor exceeds a current threshold value that corresponds to a second threshold torque value. - View Dependent Claims (18, 19, 20, 21, 22)
-
Specification