US4932131A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Position determination apparatus
Assignee: Renishaw PLC
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Filing: 1988-03-07
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Granted: 1990-06-12
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Expires: 2008-03-07
Abstract
Abstract A position determination apparatus comprising a coordinate measuring machine having a scale. In addition, a read/write head and a laser interferometer system are provided, both of which can measure the position of a probe. The head writes signals derived from the interferometer onto the scale and is used either to lay down the periodic scale marks, or to write error correction values onto the scale. The scale is thus calibrated in situ on the machine.
Inventors
- 👤 David R. McMurtry
- 👤 David Wilson
- 👤 Gillies D. Pitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:31
CPC Classifications
G; G01; G01B; G01B21/00; G01B21/02; G01B21/04; G01B21/042; G01B5/00; G01B5/0002; G01B5/0009
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
82 words
Position determination apparatus comprising as relatively fixed structure, a relatively movable structure, a scale on one of the structures, and means on the other structure for reading the scale in order to determine the relative positions of the structures, wherein the improvement comprises calibration means, independent of the scale and reading means, for determining the relative positions of the structures; and means on said other structure for writing a signal onto the scale in accordance with an output of the calibration means.
Claim 2
Dependent Claim
82 words
Position determination apparatus comprising as relatively fixed structure, a relatively movable structure, a scale on one of the structures, and means on the other structure for reading the scale in order to determine the relative positions of the structures, wherein the improvement comprises calibration means, independent of the scale and reading means, for determining the relative positions of the structures; and means on said other structure for writing a signal onto the scale in accordance with an output of the calibration means.
Claim 3
Dependent Claim
20 words
Apparatus according to claim 1, wherein the writing means is arranged to write periodically spaced scale marks onto the scale.
Claim 4
Dependent Claim
19 words
Apparatus according to claim 1, wherein the writing means is arranged to write error correction values onto the scale.
Claim 5
Dependent Claim
19 words
Apparatus according to claim 1, wherein a combined read-write head provides both the reading means and the writing means.
Claim 6
Independent Claim
119 words
A method of calibrating position determination apparatus, the apparatus comprising a relatively fixed structure, a relatively movable structure, a scale on one of the structures, and means on the other structure for reading the scale in order to determine the relative position of the structures, the method comprising: providing calibration means, independent of the scale and reading means, for determining the relative positions of the structures; moving the movable structure into a plurality of different positions relative to the fixed structure; and at each of said different positions, using the calibration means to determine the relative position and writing a signal onto the scale in dependence on the relative position thus determined, using writing means on said other structure.
Claim 7
Independent Claim
119 words
A method of calibrating position determination apparatus, the apparatus comprising a relatively fixed structure, a relatively movable structure, a scale on one of the structures, and means on the other structure for reading the scale in order to determine the relative position of the structures, the method comprising: providing calibration means, independent of the scale and reading means, for determining the relative positions of the structures; moving the movable structure into a plurality of different positions relative to the fixed structure; and at each of said different positions, using the calibration means to determine the relative position and writing a signal onto the scale in dependence on the relative position thus determined, using writing means on said other structure.
Claim 8
Dependent Claim
21 words
A method according to claim 5, wherein the writing means is arranged to write periodically spaced scale marks onto the scale.
Claim 9
Dependent Claim
20 words
A method according to claim 5, wherein the writing means is arranged to write error correction values onto the scale.
Claim 10
Dependent Claim
20 words
A method according to claim 5, wherein a combined read/write head provides both the reading means and the writing means.
References Cited (Backward Citations)
US3555254A
Cited
US3661463A
Cited
US3654446A
Cited
US4195412A
Cited
US4261107A
Cited
EP0048851A2
Cited
US4457625A
Cited
GB2162942A
Cited
JPS6165103A
Cited
US4663852A
Cited
DE3542514A1
Cited
WO1988000327A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |