Probe head
First Claim
1. A coordinate positioning apparatus having an articulating probe head for orienting a probe relative to a movable arm of the apparatus with at least one rotational degree of freedom, the probe head including:
- a base, by means of which the probe head may be mounted to the movable arm, at least one rotor, to which the probe is connectable, supported on the base in a manner permitting relative rotation of the rotor and base, a motor for rotating the rotor relative to the base, and at least one controllable heat source, actuable to generate heat within the probe head when the motor is not operating to rotate the rotor, the coordinate positioning apparatus further including a control having;
operating means for intermittently operating the motor to rotate the rotor to orient the probe;
monitoring means for continuously monitoring heat dissipated by said motor over intervals of sampling time and determining an instantaneous rate of heat dissipation;
comparing means for comparing the instantaneous rate of heat dissipation with a nominal rate of heat dissipation; and
actuating means for actuating the at least one controllable heat source to generate heat when the motor is not being operated to rotate the rotor, and the instantaneous rate of heat dissipation is lower than the nominal rate of heat dissipation.
1 Assignment
0 Petitions
Accused Products
Abstract
A probe head for a coordinate measuring machine is provided with a heat control management system which regulates the amount of heat generated within the probe head in order to provide thermal stability thereof. The heat control system includes a processor which determines the amount of current passed to one or more motors within the probe head over a predetermined time interval. The processor then determines whether auxiliary heat sources should be activated in order to provide thermal stability. In one embodiment the auxiliary heat sources are provided by passing a high frequency current through the motors of the probe head.
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Citations
16 Claims
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1. A coordinate positioning apparatus having an articulating probe head for orienting a probe relative to a movable arm of the apparatus with at least one rotational degree of freedom, the probe head including:
- a base, by means of which the probe head may be mounted to the movable arm, at least one rotor, to which the probe is connectable, supported on the base in a manner permitting relative rotation of the rotor and base, a motor for rotating the rotor relative to the base, and at least one controllable heat source, actuable to generate heat within the probe head when the motor is not operating to rotate the rotor, the coordinate positioning apparatus further including a control having;
operating means for intermittently operating the motor to rotate the rotor to orient the probe; monitoring means for continuously monitoring heat dissipated by said motor over intervals of sampling time and determining an instantaneous rate of heat dissipation; comparing means for comparing the instantaneous rate of heat dissipation with a nominal rate of heat dissipation; and actuating means for actuating the at least one controllable heat source to generate heat when the motor is not being operated to rotate the rotor, and the instantaneous rate of heat dissipation is lower than the nominal rate of heat dissipation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- a base, by means of which the probe head may be mounted to the movable arm, at least one rotor, to which the probe is connectable, supported on the base in a manner permitting relative rotation of the rotor and base, a motor for rotating the rotor relative to the base, and at least one controllable heat source, actuable to generate heat within the probe head when the motor is not operating to rotate the rotor, the coordinate positioning apparatus further including a control having;
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10. A method of operating an articulating probe head for a coordinate positioning apparatus, the probe head having:
- a base for mounting the probe head to a movable arm of the apparatus, at least one rotor to which a probe is connectable, the rotor being supported on the base in a manner permitting relative rotation of the rotor and the base, a motor for rotating the rotor relative to the base, and a controllable heat source actuable to generate heat, the method comprising the steps of;
intermittently operating the motor to rotate the rotor to orient the probe; continuously monitoring heat dissipated by the motor over intervals of sampling time, and determining an instantaneous rate of heat dissipation; comparing the instantaneous rate of heat dissipation with a nominal rate of heat dissipation; and actuating the controllable heat source to generate heat when the motor is not being operated to rotate the rotor, and the instantaneous rate of heat dissipation is lower than the nominal rate of heat dissipation. - View Dependent Claims (11, 12, 13, 14, 15, 16)
- a base for mounting the probe head to a movable arm of the apparatus, at least one rotor to which a probe is connectable, the rotor being supported on the base in a manner permitting relative rotation of the rotor and the base, a motor for rotating the rotor relative to the base, and a controllable heat source actuable to generate heat, the method comprising the steps of;
Specification