Optical torque sensor
First Claim
Patent Images
1. A torque sensor comprising:
- a sensor housing;
a sensor input member at least partially received in the sensor housing;
a sensor output member at least partially received in the sensor housing;
a torsionally resilient coupling member that couples the sensor input member to the sensor output member; and
an optical sensor system that includes a light source, at least one encoder and at least one optical sensor, the at least one encoder periodically transmitting light between the light source and the at least one optical sensor based on an amount of relative rotation between the sensor input member and the sensor output member;
the sensor input member and the sensor output member being rotatably disposed about a common axis;
the at least one encoder including an annular ring with a plurality of circumferentially spaced apart teeth.
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Abstract
A torque sensor that includes a sensor housing, a sensor input member at least partially received in the sensor housing, a sensor output member at least partially received in the sensor housing, a torsionally resilient coupling member that couples the sensor input member to the sensor output member and an optical sensor system that includes a light source, one or more encoders and one or more optical sensors. The encoder or encoders periodically transmit light between the light source and the at least one optical sensor based on an amount of relative rotation between the sensor input member and the sensor output member.
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Citations
17 Claims
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1. A torque sensor comprising:
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a sensor housing; a sensor input member at least partially received in the sensor housing; a sensor output member at least partially received in the sensor housing; a torsionally resilient coupling member that couples the sensor input member to the sensor output member; and an optical sensor system that includes a light source, at least one encoder and at least one optical sensor, the at least one encoder periodically transmitting light between the light source and the at least one optical sensor based on an amount of relative rotation between the sensor input member and the sensor output member; the sensor input member and the sensor output member being rotatably disposed about a common axis; the at least one encoder including an annular ring with a plurality of circumferentially spaced apart teeth. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A power tool comprising:
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a tool portion having a motor and a transmission; and a torque sensor that includes a rotatable sensor input member that is coupled for rotation with an output member of the transmission, a rotatable sensor output member, a torsionally resilient coupling member that couples the sensor input member to the sensor output member, and an optical sensor system that employs light to correlate relative rotation between the sensor input member and the sensor output member to a magnitude of a torque that is transmitted through the torque sensor; the optical system includes a first encoder and a second encoder and an amount of light that is transmitted through the first and second encoders varies in response to the magnitude of the torque that is transmitted through the torque sensor in a predetermined direction; the first and second encoders have a pair of windows that overlap one another to permit light to be transmitted through the first and second encoders; and each of the windows has a pair of circumferentially-extending edges that diverge away from one another. - View Dependent Claims (12, 13, 14)
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15. A power tool comprising:
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a tool portion having a motor and a transmission; and a torque sensor that includes a rotatable sensor input member that is coupled for rotation with an output member of the transmission, a rotatable sensor output member, a torsionally resilient coupling member that couples the sensor input member to the sensor output member, and an optical sensor system that employs light to correlate relative rotation between the sensor input member and the sensor output member to a magnitude of a torque that is transmitted through the torque sensor; the optical system includes a first encoder and a second encoder and an amount of light that is transmitted through the first and second encoders varies in response to the magnitude of the torque that is transmitted through the torque sensor in a predetermined direction; and an amount of light that is transmitted through the first and second encoders decreases as increasing torque is transmitted through the torque sensor in a direction opposite the predetermined direction. - View Dependent Claims (16)
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17. A power tool comprising:
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a tool portion having a motor and a transmission; and a torque sensor that includes a rotatable sensor input member that is coupled for rotation with an output member of the transmission, a rotatable sensor output member, a torsionally resilient coupling member that couples the sensor input member to the sensor output member, and an optical sensor system that employs light to correlate relative rotation between the sensor input member and the sensor output member to a magnitude of a torque that is transmitted through the torque sensor; the optical system includes a first encoder and a second encoder and an amount of light that is transmitted through the first and second encoders varies in response to the magnitude of the torque that is transmitted through the torque sensor in a predetermined direction; and an amount of light that is transmitted through the first and second encoders changes based an amount of relative rotation between the first and second encoders and wherein the change is non-linear.
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Specification