Patent US3614575A successfully refreshed from Google Patents.
US3614575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Numerical control system with controlled dwell
Assignee: Bendix Corp
•
Filing: 1970-08-05
•
Granted: 1971-10-19
•
Expires: 1990-08-05
Abstract
Abstract A numerical control system for a lathe includes means for inhibiting the execution of one of a series of commanded motions until the previous command has been acted on for a sufficient time to insure its execution. The system measures the error between the actual and commanded positions of the controlled part by comparing the phase displacement between the reference and command square waves in a phase analog servo. When the commandposition error reaches a predetermined minimum value, indicating that the cutter is very close to its commanded position, pulses generated upon each incremental rotation movement of the spindle are counted until a number has been reached indicating one full spindle revolution. At that point the inhibition of the subsequent command is removed.
Inventors
- 👤 Hymie Cutler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:01
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/182; G05B2219/00; G05B2219/30; G05B2219/34; G05B2219/34388; G05B2219/45; G05B2219/45248; G05B2219/49; G05B2219/49397
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
122 words
In a control system for a machine tool operative to control the position of the machine tool cutter with respect to a workpiece through a sequence of positions in accordance with a sequence of numerical commands, means, under control of a numerical command, for inhibiting the execution of a given command in the sequence, said means comprising: means for sensing the completion of a command in the sequence previous to the given command; means for measuring motion of the tool with respect to the workpiece, and means for providing a control signal operative to inhibit the execution of said given commands until a predetermined motion of the cutter with respect to the workpiece has occurred, following the completion of said previous command.
Claim 2
Dependent Claim
122 words
In a control system for a machine tool operative to control the position of the machine tool cutter with respect to a workpiece through a sequence of positions in accordance with a sequence of numerical commands, means, under control of a numerical command, for inhibiting the execution of a given command in the sequence, said means comprising: means for sensing the completion of a command in the sequence previous to the given command; means for measuring motion of the tool with respect to the workpiece, and means for providing a control signal operative to inhibit the execution of said given commands until a predetermined motion of the cutter with respect to the workpiece has occurred, following the completion of said previous command.
Claim 3
Dependent Claim
40 words
The system of claim 1 wherein said means for sensing the completion of a command in the sequence comprises means for comparing the commanded position of the cutter relative to the workpiece with its actual position relative to the workpiece.
Claim 4
Dependent Claim
36 words
The system of claim 2 wherein the system employs a servo and a resolver and the actual position of the cutter with respect to the workpiece is determined by inspection of the output of the resolver.
Claim 5
Dependent Claim
56 words
The system of claim 3 wherein the servo employs a command counter and a reference counter and the comparison of the actual position of the cutter with respect to the workpiece with its commanded position with respect to the workpiece is made by comparing the output of the resolver with the output of the reference counter.
Claim 6
Dependent Claim
48 words
The system of claim 1 wherein the means for measuring the motion of the tool with respect to the workpiece includes a transducer operative to provide an electrical pulse for each increment of motion of the cutter with respect to the workpiece and means for counting such pulses.
Claim 7
Dependent Claim
28 words
The system of claim 5 wherein the machine tool includes a rotary spindle and the transducer provides an output pulse for each increment of rotation of the spindle.
Claim 8
Independent Claim
197 words
A system for controlling the operation of a machine tool having a rotary spindle and a cutter movable with respect to such spindle, comprising: a source of a series of numerical commands relating to desired sequential motions of the cutter relative to the spindle; a drive system for said spindle; a drive spindle for said cutter; means for receiving said sequence of numerical commands in serial order and for generating control signals for both said drives of such nature as to cause said cutter to move with respect to said workpiece through said sequential motions; and means for inhibiting the generation of control signals to at least one of said drives under control of a numerical command contained in said sequence, said last said means comprising means for generating a control signal which inhibits the execution of a given command in the sequence, means for measuring the completion of a command in the sequence previous to said given command, means for measuring the rotation of the spindle, and means for terminating said control signal upon the spindle undergoing a predetermined rotation following the achievement of a predetermined degree of completion of said previous command in said sequence.
Claim 9
Independent Claim
197 words
A system for controlling the operation of a machine tool having a rotary spindle and a cutter movable with respect to such spindle, comprising: a source of a series of numerical commands relating to desired sequential motions of the cutter relative to the spindle; a drive system for said spindle; a drive spindle for said cutter; means for receiving said sequence of numerical commands in serial order and for generating control signals for both said drives of such nature as to cause said cutter to move with respect to said workpiece through said sequential motions; and means for inhibiting the generation of control signals to at least one of said drives under control of a numerical command contained in said sequence, said last said means comprising means for generating a control signal which inhibits the execution of a given command in the sequence, means for measuring the completion of a command in the sequence previous to said given command, means for measuring the rotation of the spindle, and means for terminating said control signal upon the spindle undergoing a predetermined rotation following the achievement of a predetermined degree of completion of said previous command in said sequence.
Claim 10
Dependent Claim
37 words
The system of claim 7 wherein a predetermined degree of completion of said previous command in the sequence occurs at a point in time slightly previous to the full completion of said previous command in the sequence.
Claim 11
Dependent Claim
78 words
The system of claim 7 wherein the control signal for the cutter drive constitutes a train of pulses, the drive includes a reference counter, a command counter, the command counter receiving said train of pulses, and a resolver having one winding connected to the output of one of the counters and the means for sensing the completion of a command in the sequence comprises means for comparing phases of the output of the resolver and the other counter.
Claim 12
Dependent Claim
71 words
The system of claim 8 wherein the means for comparing the phase of the output of the resolver with the other counter includes a source of pulses, a counter, and gate means operative to connect the source of pulses to the counter during the time between the transition of the output of the resolver in one direction and the transition of the output of the other counter in the same direction.
Claim 13
Dependent Claim
55 words
The system of claim 10 wherein the cutter is movable with respect to the tool along a pair of mutually perpendicular axes, a drive is provided for each of the axes, and means for comparing the phase of the other counter with the phase of the output of the resolver is provided for each axis.
Claim 14
Dependent Claim
173 words
In a control system for the position of a cutter of a machine tool with respect to a workpiece, in combination: a source of a series of numerical commands, each including information relating to one of the sequence of motions of the cutter with respect to the workpiece; a drive system for said cutter; a drive system for said workpiece; means for receiving said numerical commands sequentially and for generating sequences of control signals representative of said commands for said drives; and means for inhibiting the generation of a control signal representative of one command including means for determining the difference between the commanded position of the cutter and the actual position of the cutter, means for generating a first control signal upon such difference achieving a predetermined level; means for measuring the motion of the workpiece with respect to the cutter, and means for generating a second control signal upon the completion of a predetermined motion of the workpiece with respect to the cutter after the generation of said first control signal.
Claim 15
Dependent Claim
173 words
In a control system for the position of a cutter of a machine tool with respect to a workpiece, in combination: a source of a series of numerical commands, each including information relating to one of the sequence of motions of the cutter with respect to the workpiece; a drive system for said cutter; a drive system for said workpiece; means for receiving said numerical commands sequentially and for generating sequences of control signals representative of said commands for said drives; and means for inhibiting the generation of a control signal representative of one command including means for determining the difference between the commanded position of the cutter and the actual position of the cutter, means for generating a first control signal upon such difference achieving a predetermined level; means for measuring the motion of the workpiece with respect to the cutter, and means for generating a second control signal upon the completion of a predetermined motion of the workpiece with respect to the cutter after the generation of said first control signal.
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) | 1974-10-18 | 1975-04-19 | 1975-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-18 | 1979-04-19 | 1979-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-18 | 1983-04-19 | 1983-10-19 | $7700.00 | Window Closed / Lapsed |