Mounting for surface-sensing stylus and a method of using said mounting
First Claim
1. Apparatus for use on a coordinate positioning machine in measuring a surface, the machine having a head movable relative to a table on which said surface is supported, the apparatus comprising:
- a base connectable to the head;
a first rotor supporting a surface-sensing device, the first rotor being mounted to, and for rotation relative to the base about a first axis;
a first motor for rotating the first rotor about said first axis in response to an input signal;
first transducing means for measuring, relative to a reference orientation, an angle of rotation of the first rotor about the first axis; and
first controlling means for providing;
(a) a torque input signal or operating said first motor to apply a constant torque to said first rotor; and
b) a positioning input signal for operating said first motor to position said first rotor at a given angle of rotating relative to said reference orientation,wherein said first controlling means is selectively operable for passing on of said torque input signal and said positioning input signal to the motor as said input signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A mounting comprises a base supporting a first rotary motor whose shaft has secured thereto a housing supporting a second rotary motor whose shaft has the stylus secured thereto. Each motor is operable optionally in a constant torque mode and a positioning mode and each motor has an angular position transducer. In use, the base is secured to the operating member of a coordinate measuring machine and the machine is driven through a path such that the free end of the stylus can maintain engagement with the surface of a workpiece under the force generated by one of the motors while that motor is in the constant torque mode. The profile of said surface is then determined as a function of the coordinate position of the operating member, the angular position and the length of the stylus.
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Citations
9 Claims
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1. Apparatus for use on a coordinate positioning machine in measuring a surface, the machine having a head movable relative to a table on which said surface is supported, the apparatus comprising:
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a base connectable to the head; a first rotor supporting a surface-sensing device, the first rotor being mounted to, and for rotation relative to the base about a first axis; a first motor for rotating the first rotor about said first axis in response to an input signal; first transducing means for measuring, relative to a reference orientation, an angle of rotation of the first rotor about the first axis; and first controlling means for providing; (a) a torque input signal or operating said first motor to apply a constant torque to said first rotor; and b) a positioning input signal for operating said first motor to position said first rotor at a given angle of rotating relative to said reference orientation, wherein said first controlling means is selectively operable for passing on of said torque input signal and said positioning input signal to the motor as said input signal. - View Dependent Claims (2, 3, 4)
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5. A method of operating an apparatus comprising a surface-sensing stylus for mounting on a head of a coordinate positioning machine, the surface-sensing stylus being rotatable about first and second axes by means of first and second motors respectively, to contact a surface, the method comprising the steps of:
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driving the head of the machine along a path adjacent a plane of the local surface; applying a torque input signal to one of the first and second motors, thereby to urge the surface-sensing stylus into contact with the surface; and applying to the other of the first and second motors positioning input signals such that said surface-sensing stylus has an oscillatory motion transverse to the path of the head of the machine.
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6. A method of scanning a surface of a workpiece with a surface sensing device, the device being supported on a head of a coordinate positioning machine by amounting device providing movement of said surface sensing device with 2 degrees of freedom relative to said head, the workpiece being supported on a table of the machine relative to which said head is movable, the method comprising the steps of:
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operating the machine to drive the head in a first direction along a path adjacent the workpiece surface; simultaneously operating the mounting device to move the surface sensing device into a sensing relationship with the surface, along a second direction, the second direction being transverse to said first direction and the plane of the local surface; simultaneously operating the mounting device to move the surface sensing device with an oscillatory motion substantially parallel to the plane of the local surface; and measuring, at predetermined intervals of time; a) the position of the surface sensing device relative to the head; and b) the position of th head relative to the table. - View Dependent Claims (7, 8, 9)
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Specification