US3708736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for correcting errors in the position of a work article making a linear motion by means of a drive screw
Assignee: Toshiba Corp
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Filing: 1971-07-09
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Granted: 1973-01-02
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Expires: 1991-07-09
Abstract
Abstract A control system wherein a work article or load, such as a work table, is made to travel linearly by a drive screw; and the position of said work article is determined by a servo system including comparing an amount of control corresponding to the rotation angle of the drive screw with a predetermined value of input supplied to the system. There are detected errors in the position of the work article resulting from the drive screw by a reference screw disposed parallel with the travelling direction of the work article so as to operate interlockingly with the drive screw in combination with a displacement detector mounted on the work article so as to operate interlockingly with the reference screw. There are supplied output signals from the displacement detector to the servo system to correct errors in the position of the work article.
Inventors
- 👤 N Hoshina
- 👤 E Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:25
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/21; G05B19/23; G05B19/231; G05B19/232; G05B2219/00; G05B2219/30; G05B2219/41; G05B2219/41067
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
198 words
A control system for acurately defining the position of a work article comprising: drive means for causing the work article to travel linearly by a drive screw; said drive screw having a first degree of lead screw error; a rotation angle detecting means for producing signals corresponding to the angle through which said drive screw is made to rotate by said drive means; a servo system for determining the position of the work article by collating said output signals from said detection means with the predetermined values of input; a reference screw disposed parallel with the traveling direction of said work article and arranged to operate interlockingly with said drive screw; said reference screw having a degree of lead screw error less than the degree of lead screw error of said drive screw; a displacement detector fitted to said work article for engaging said reference screw so as to detect errors in said work article position caused by the difference of lead screw error between said drive screw and said reference screw; means for correcting said errors according to output signals from said displacement detector whereby said work article is caused to travel linearly at a constant velocity.
Claim 2
Dependent Claim
198 words
A control system for acurately defining the position of a work article comprising: drive means for causing the work article to travel linearly by a drive screw; said drive screw having a first degree of lead screw error; a rotation angle detecting means for producing signals corresponding to the angle through which said drive screw is made to rotate by said drive means; a servo system for determining the position of the work article by collating said output signals from said detection means with the predetermined values of input; a reference screw disposed parallel with the traveling direction of said work article and arranged to operate interlockingly with said drive screw; said reference screw having a degree of lead screw error less than the degree of lead screw error of said drive screw; a displacement detector fitted to said work article for engaging said reference screw so as to detect errors in said work article position caused by the difference of lead screw error between said drive screw and said reference screw; means for correcting said errors according to output signals from said displacement detector whereby said work article is caused to travel linearly at a constant velocity.
Claim 3
Dependent Claim
78 words
The control system according to claim 1 wherein said servo system comprises an error register adapted to receive signals denoting a difference between the values of output from said rotation angle detecting means and the predetermined values of input; a digital-to-analog converter for converting a digital quantity from said error register to an analog quantity; and a differential amplifier connected to said converter and displacement detector so as to actuate said drive unit according to the resultant output.
Claim 4
Dependent Claim
97 words
The control system according to claim 1 wherein the servo system comprises an analog-to-digital converter for converting an analog quantity from said displacement detector to a digital quantity; an error register adapted to receive values obtained by collating the values of output from said analog-to-digital converter with the values previously provided by comparing the values of output from said rotation angle detector with the prescribed values of input; and a digital-to-analog converter for converting a digital quantity from said error register to an analog quantity so as to actuate said drive unit according to the resultant output.
Claim 5
Dependent Claim
26 words
The control system according to claim 1 wherein said displacement detector is an electric micrometer provided with a contact member which directly contacts said reference screw.
Claim 6
Dependent Claim
29 words
The control system according to claim 1 wherein said displacement detector is an electric micrometer provided with a contact member which contacts a cam unrotatively engaging the reference screw.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |