US3573363A

US3573363A - Coordinate axis drive system for a coordinatograph

Info

Publication number: US3573363A
Application number: US717850A
Authority: US
Inventors: William A Ford
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1968-04-01
Filing date: 1968-04-01
Publication date: 1971-04-06
Anticipated expiration: 1988-04-06
Also published as: FR2005274A1; DE1904664A1

Abstract

This specification describes a control system for a twodimensional scanner head in a coordinatograph. A closed electrical circuit comprising a synchrotorque transmitter and a synchrotorque receiver is used to power the scanner assembly along coordinate one axis. Another closed electrical circuit comprising a control transmitter and a control transformer power the scanner assembly in the direction of a second coordinate axis. The friction forces involved in effecting incremental adjustments in the direction of the second axis are higher than the corresponding forces developed in the adjustment in the direction of the first axis.

Description

United States Patent lnventor William A. Ford Southl'ield, Mich.

App]. No. 717,850

Filed Apr. 1, 1968 Patented Apr. 6, 1971 Assignee Ford Motor Company Dearborn, Mich.

COORDINATE AXIS DRIVE SYSTEM FOR A COORDINATOGRAPH 11 Claims, 61 Drawing Figs.

US. Cl. l78/6.8, 346/3 3 Int. Cl. H04n 5/30 Field of Search 346/33 (MCR); 250/202; 178/68 References Cited UNITED STATES PATENTS Eller..... 318/30 3,032,881 5/1962 Fengler 33/23 3,105,907 10/1963 Colten et al. 250/202 3,178,717 4/1965 Fengler 346/33 3,398,452 8/1968 Little et al. 33/18 Primary Examiner-Robert L. Griffin Assistant Examiner-Richard K. Eckert, Jr. Att0rneysJ0hn R. Faulkner and Donald J. l-larrinton ABSTRACT: This specification describes a control system for a two-dimensional scanner head in a coordinatograph. A closed electrical circuit comprising a synchrotorque transmitter and a synchrotorque receiver is used to power the scanner assembly along coordinate one axis. Another closed electrical circuit comprising a control transmitter and a control transformer power the scanner assembly in the direction of a second coordinant axis. The friction forces involved in effecting incremental adjustments in the direction of the second axis are higher than the corresponding forces developed in the adjustment in the direction of the first axis.

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Claims

1. A contour data recording system comprising a draft plate supporting table (10), a coordinate X-axis and Y-axis carrier assembly comprising a carriage beam (90) extending over the plane of said table (10) in close proximity thereto and in parallel disposition therewith, said beam (90) being situated with its principal geometric axis in the direction of the coordinate Yaxis, a crossmember (44) supporting one end of said beam (90), said crossmember (44) being movably mounted on said table (10) on one margin thereof, the motion of said crossmember (44) in the Xaxis direction, an electrical impulse generator (130) carried by said beam and drivably coupled thereto whereby it is adapted to generate an electrical impulse voltage for each increment of movement of said generator in the Y-axis direction, a carrier (104) movably mounted on said beam (90) and supporting said impulse generator (130), an optical scanner (128) carried by said carrier (104), a second impulse voltage generator (74) carried by said crossmember (44), said second impulse generator being coupled drivably to said table (10) whereby it is adapted to generate a voltage impulse for each increment of movement of said beam (90) in the X-axis direction, synchronous driving and driven electrical units (186,290) each having multiple coil stators (360,362) connected together electrically and electrical rotor windings (364,366) cooperating with their respective stators in phased relationship, a force transmitting driving connection between the rotor windings of one synchronous unit and said carrier, and operator-controlled drive means (298) for rotating the rotor windings for the other synchronous electrical unit whereby Y-axis adjustments of said scanner can be accomplished.

2. The combination as set forth in claim 1 including a second pair of synchronous electrical units (248,290) with stators (368, 370) having movable coils connected electrically and cooperating wound rotors whereby manual displacement of the rotor of one of said second pair of units with respect to its stator results in the generation of a torque on the rotor of the other of said second pair of units, means (133) for drivably connecting mechanically the rotor of the other of said second pair of units to said crossmember whereby X-axis adjustments of said beam can be accomplished, and means (324) for manually adjusting the angular position of the rotor of the first of said second pair of units.

3. The combination as set forth in claim 2 wherein the electrical synchronous unit carried by the crossmember comprises a control transformer and its associated electrical unit comprises a torque transmitter, the control transformer and said torque transmitter each having electrically-connected, multiple-winding, stationary stators and a movable wound rotor, the rotor of the torque transmitter being connected mechanically to said manually adjusting means, the rotor of said control transformer being connected mechanically to said crossmember whereby the latter sends to said rotor a position feedback signal, a servomotor having an armature and a stator, the stator of said servomotor being connected electrically to the rotor of said control transformer, said last-mentioned connection including a voltage amplifier adapted to magnify the error signal generated in the rotor windings of said control transformer, and a mechanical connection between the armature for said servomotor and said crossmember whereby said scanner is adjusted in either X-axis direction depending upon the direction of rotation of the rotor of said control transformer.

4. The combination as set forth in claim 3 wherein the armature of said servomotor is connected to a DC tachometer voltage generator, the output of said tachometer generator being connected to the input side of said amplifier, the input side of said amplifier, the output side of said tachometer generator and the output side of said control transformer rotor being connected together at a voltage summing point whereby the output voltage of said tachometer generator opposes the error signal voltage generated by said control transformer as the rotor of said torque transmitter is displaced by the operator with respect to its stationary stator.

5. The combination as set forth in claim 3 wherein said scanner comprises a television camera carried by said carrier, said camera having a lens situated directly over the surface of said table on one side of said beam, a television monitor circuit for receiving the signals of said camera whereby the operator may observe the position of said lens with respect to a target point, a position digitizer circuit means for recording the coordinant values of selected points scanned by said scanner, said digitizer being connected electrically to each of said voltage impulse generators whereby the individual voltage impulses are counted and recorded to permit location of selected points with respect to a predefined origin point in terms of both X-axis coordinant and Y-axis coordinant.

6. A contour data recording system comprising a draft plate supporting table, a coordinate X-axis and Y-axis carrier assembly comprising a carriage beam extending over the plane of said table in close proximity thereto and in parallel disposition therewith, said beam being situated with its principal geometric axis in the direction of the coordinate Y-axis, a crossmember supporting one end of said beam, said crossmember being movably mounted on said table on one margin thereof, the direction of motion of said crossmember being parallel to the X-axis direction, an electrical impulse generator carried by said beam and drivably coupled thereto whereby it is adapted to generate an electrical impulse voltage for each incremental movement thereof in a Y-axis direction, a carrier movably mounted on said beam and supporting said impulse generator, an optical scanner carried by said carrier, a second impulse voltage generator carried by said crossmember, said second impulse generator being coupled drivably to said table whereby it is adapted to generate a voltage impulse for each incremental movement of said beam in an X-axis direction, synchronous driving and driven electrical units each having multiple coil stators connected together electrically and electrical rotor windings cooperating with their respective stators in phased relationship, one of said driven electrical units being mounted on said crossmember and another being mounted on said carrier, a first torque transmitting driving connection between the windings of a first synchronous unit on said crossmember and said carrier, a second torque transmitting driving connection between the windings of a second synchronous unit on said carrier and said beam, and operator-controlled drive means for rotating the windings for each of the other synchronous electrical units whereby manual Y-axis adjustments and X-axis adjustments of said scanner can be accomplished, the drive means for driving the windings of said other units comprising both a coarse adjustment hand element and a fine adjustment hand element connected drivably to the associated windings, said drive means including speed reducing gears between one of said fine adjustment hand elements and its associated rotor windings to permit increased sensitivity in the adjustment of said scanner in the Y-axis direction.

7. A contour data recording system comprising a draft plate supporting table, a coordinate X-axis and Y-axis carrier assembly comprising a carriage beam extending over the plane of said table in close proximity thereto and in parallel disposition therewith, said beam being situated with its principal geometric axis in the direction of the coordinate Y-axis, a crossmember supporting one end of said beam, said crossmember being movably mounted on said table on one margin thereof, the direction of motion of said crossmember being parallel to the X-axis direction, an electrical impulse generator carried by said beam and drivably coupled thereto whereby it is adapted to generate an electrical impulse voltage for each incremental movement thereof in a Y-axis direction, a carrier movably mounted on said beam and supporting said impulse generator, an optical scanner carried by said carrier, a second impulse voltage generator carried by said crossmember, said second impulse generator being coupled drivably to said table whereby it is adapted to generate a voltage impulse for each incremental movement of said beam in an X-axis direction, two synchronous driving electrical units and two synchronous driven electrical units, each having multiple coil stators the stators of one driving unit and one driven unit being connected together electrically, the stators of the other driving unit and the other driven unit being connected together electrically, electrical rotor windings cooperating with each stator in phased relationship, one driven unit being mounted on said crossmember and the other driven unit being mounted on said carrier a torque transmitting driving connection between the windings of said one driven unit and said carrieR, and operator controlled drive means for rotating the windings for the synchronous driving electrical units whereby Y-axis adjustments and X-axis adjustments of said scanner can be accomplished, another torque transmitting driving connection between the windings the other driven unit and said crossmember, said drive means comprising separate coarse adjustment hand elements connected to the respective rotor windings with a first driving ratio and a fine adjustment hand element and a speed-reducing gearing between said fine adjustment hand element and its associated rotor.

8. The combination as set forth in claim 6 wherein the electrical synchronous unit carried by the crossmember comprises a control transformer and its associated electrical unit comprising a torque transmitter, the control transformer and said torque transmitter each having electrically-connected, multiple-winding, stationary stators and a movable wound rotor, the rotor of the torque transmitter being connected mechanically to the associated drive means, the rotor of said control transformer being connected mechanically to said crossmember, a servomotor, an electrical connection between said servomotor and the rotor of said control transformer, said last-mentioned connection including a voltage amplifier adapted to magnify the error signal generated in the rotor windings of said control transformer, and a mechanical connection between said servomotor and said crossmember whereby said scanner is adjusted in either X-axis direction depending upon the direction of rotation of the rotor of said control transformer.

9. The combination as set forth in claim 8 wherein the connection between said servomotor and said crossmember comprises a speed-reducing gear assembly the input element of which is connected to said servomotor, and drive elements connected to the output element of said gear assembly comprising a flexible member connected to said crossmember and trained over one of said drive elements and extending in a plane parallel to the plane of said table.

10. The combination as set forth in claim 7 wherein said scanner comprises a television camera carried by said carrier, said camera having a lens situated directly over the surface of said table on one side of said beam, a television monitor circuit for receiving the signals of said camera whereby the operator may observe the position of said lens with respect to a target point, and a position digitizer circuit means for recording the coordinate values of selected points scanned by said scanner, said digitizer being connected electrically to each of said voltage impulse generators whereby the individual voltage impulses are counted and recorded to permit location of selected points with respect to a predefined origin point in terms of both X-axis coordinate and Y-axis coordinate.

11. The combination as set forth in claim 9 wherein said scanner comprises a television camera carried by said carrier, said camera having a lens situated directly over the surface of said table on one side of said beam, a television monitor circuit for receiving the signals of said camera whereby the operator may observe the position of said lens with respect to a target point, and a position digitizer circuit means for recording the coordinate values of selected points scanned by said scanner, said digitizer being connected electrically to each of said voltage impulse generators whereby the individual voltage impulses are counted and recorded to permit location of selected points with respect to a predefined origin point in terms of both X-axis coordinate and Y-axis coordinate.