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Patent US3740535A successfully refreshed from Google Patents.
US3740535A
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Numerical contouring control system
Assignee: Westinghouse Electric Corp
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Filing: 1971-08-16
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Granted: 1973-06-19
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Expires: 1991-08-16
Abstract
Abstract This disclosure relates to a numerical contouring control system for controlling the displacements of a machine tool along two or more axes in response to intelligence indicia on a control media such as a tape. The time required to complete one block of information is arranged in digital form as an arithmetical numerator. The displacements in rectangular coordinate directions are respectively arranged in digital form as arithmetical denominators. Successively, each denominator is subtracted from the numerator. When a change in sign in the remainder is detected, a position signal is sent to command an incremental displacement Delta L along a rectangular coordinate direction. Upon detecting a change in sign in the remainder, the digital information in the numerator is added to the remainder at the advent of the next subtraction. The subtraction process is iterative and continues until the position demand is equated to the end displacement indicator by the intelligence on the control media. A cooperating sero system continues to actuate associated drive mechanisms until the position demand and the actual position produce zero error signal. When the rectangular coordinates are part of a circular quadrant, the denominator for each coordinate is appropriately adjusted as subtraction proceeds, the denominator for one of said coordinates being incrementally increased, while the denominator for the other coordinate is decrementally decreased.
Inventors
- 👤 A Szabo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:58
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/41; G05B19/4103
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
245 words
Numerical control contouring system for a machine tool, said system providing position command signals which are a function of incremental displacements Delta L along rectangular coordinate directions, said system being actuated in response to at least one block of intelligence indicia on a control media comprising: a. means responsive to said control media fOr providing an arithmetical numerator in digital form which is a function of the time required to execute the commands derived from the intelligence contained in said block; b. means responsive to said control media for providing an arithmetical denominator in digital form which is a function of the required displacements in said rectangular coordinate directions, respectively, in accordance with said block of intelligence; c. means connected with said arithmetical denominator means adapted to digitally increment and decrement said denominator means respectively when said block of information depicts circular interpolation, and adapted to be digitally passive when said block of intelligence depicts linear interpolation; d. means, coupled to said arithmetical numerator and denominator means, for successively digitally subtracting said denominator means from said numerator means; e. means cooperating with said subtracting means for detecting a change in sign in the remainder as successive subtractions proceed, and for permitting the addition of the digital information in said numerator means to said remainder at the advent of the next subtraction; and f. means responsive to said detecting and permitting means for delivering said position command signals at the occurrence of said change in sign.
Claim 2
Dependent Claim
245 words
Numerical control contouring system for a machine tool, said system providing position command signals which are a function of incremental displacements Delta L along rectangular coordinate directions, said system being actuated in response to at least one block of intelligence indicia on a control media comprising: a. means responsive to said control media fOr providing an arithmetical numerator in digital form which is a function of the time required to execute the commands derived from the intelligence contained in said block; b. means responsive to said control media for providing an arithmetical denominator in digital form which is a function of the required displacements in said rectangular coordinate directions, respectively, in accordance with said block of intelligence; c. means connected with said arithmetical denominator means adapted to digitally increment and decrement said denominator means respectively when said block of information depicts circular interpolation, and adapted to be digitally passive when said block of intelligence depicts linear interpolation; d. means, coupled to said arithmetical numerator and denominator means, for successively digitally subtracting said denominator means from said numerator means; e. means cooperating with said subtracting means for detecting a change in sign in the remainder as successive subtractions proceed, and for permitting the addition of the digital information in said numerator means to said remainder at the advent of the next subtraction; and f. means responsive to said detecting and permitting means for delivering said position command signals at the occurrence of said change in sign.
Claim 3
Dependent Claim
77 words
Numerical control contouring system according to claim 1 in which: a. said means for providing an arithmetical numerator comprises shift register means and gating means, said gating means being coupled to the input of said shift register means and being logically adapted at the first iteration to permit passage of the digital numerical intelligence to said shift register, and then to block further input until the beginning of the next block of intelligence on said control media.
Claim 4
Dependent Claim
79 words
Numerical control contouring system according to claim 1 in which: d. said means coupled to said arithmetic numerator for successive digital subtraction comprise remainder shift register means, full adder means, gating means, said full adder means being coupled to said arithmetic numerator and denominator means to perform algebraic addition, said gating means being coupled between the last stage of said remainder shift means and said full adder means to provide recirculation of the contents of said remainder shift register.
Claim 5
Dependent Claim
75 words
Numerical control contouring system according to claim 1 in which: e. said means for detecting and permitting comprise 1 bit shift register means and cooperating gating means, said 1 bit shift register means being coupled to the subtracting means for detecting a change of sign and for enabling said cooperating gating means to permit the digital intelligence in said arithmetical numerator means to pass to said subtracting means at the advent of the next subtraction.
Claim 6
Dependent Claim
114 words
Numerical control contouring system according to claim 1 in which: f. said responsive means comprising position demand counter means, end position counter means, and comparator means, said position demand means receiving count signals from said detecting means at a change in sign, said end position counter means receiving count signals as a function of the end position displacement intelligence from said control media, said comparator means being adapted to compare the counts in said demand counter means and said end position counter means and for inhibiting further counting of said position demand counter means when said compared counts are equal, the successive counts in said position demand counter means defining said position command signals.
Claim 7
Dependent Claim
49 words
Numerical control contouring system according to claim 1 including: g. transducer means for providing incremental positional signals as a function of the actual incremental displacements along said rectangular coordinate directions; and h. means for comparing said incremental positional signals with said position command signals to derive position error signals.
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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |