US3124691A - light sensitive line tracing apparatus - Google Patents

light sensitive line tracing apparatus Download PDF

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Publication number
US3124691A
US3124691A US5692060A US3124691A US 3124691 A US3124691 A US 3124691A US 5692060 A US5692060 A US 5692060A US 3124691 A US3124691 A US 3124691A
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Prior art keywords
line
sensitive area
photocell
opaque
image
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Stewart Warner Corp
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Stewart Warner Corp
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Priority to US5692060 priority Critical patent/US3124691A/en
Priority to DEST18108A priority patent/DE1232243B/de
Priority to NL268792A priority patent/NL120793C/xx
Priority to FR873500A priority patent/FR1301550A/fr
Priority to GB33389/61A priority patent/GB995421A/en
Application granted granted Critical
Publication of US3124691A publication Critical patent/US3124691A/en
Priority to NL6514970A priority patent/NL6514970A/xx
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    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K11/00—Methods or arrangements for graph-reading or for converting the pattern of mechanical parameters, e.g. force or presence, into electrical signal
    • G06K11/02—Automatic curve followers, i.e. arrangements in which an exploring member or beam is forced to follow the curve
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K7/00—Cutting, scarfing, or desurfacing by applying flames
    • B23K7/002—Machines, apparatus, or equipment for cutting plane workpieces, e.g. plates
    • B23K7/004—Seam tracking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q35/00—Control systems or devices for copying directly from a pattern or a master model; Devices for use in copying manually
    • B23Q35/04—Control systems or devices for copying directly from a pattern or a master model; Devices for use in copying manually using a feeler or the like travelling along the outline of the pattern, model or drawing; Feelers, patterns, or models therefor
    • B23Q35/08—Means for transforming movement of the feeler or the like into feed movement of tool or work
    • B23Q35/12—Means for transforming movement of the feeler or the like into feed movement of tool or work involving electrical means
    • B23Q35/127—Means for transforming movement of the feeler or the like into feed movement of tool or work involving electrical means using non-mechanical sensing
    • B23Q35/128—Sensing by using optical means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q35/00—Control systems or devices for copying directly from a pattern or a master model; Devices for use in copying manually
    • B23Q35/04—Control systems or devices for copying directly from a pattern or a master model; Devices for use in copying manually using a feeler or the like travelling along the outline of the pattern, model or drawing; Feelers, patterns, or models therefor
    • B23Q35/24—Feelers; Feeler units
    • B23Q35/38—Feelers; Feeler units designed for sensing the pattern, model, or drawing without physical contact
    • B23Q35/40—Feelers; Feeler units designed for sensing the pattern, model, or drawing without physical contact involving optical or photoelectrical systems

Definitions

  • This invention relates to line sensing devices such as are useful in apparatus to control the patterns of torch cutters, wood sawing machines, clothes cutters, welding tools, milling machines and the like. More particularly, this invention relates to guidance elements and systems using photosensitive means of the general character shown and described in U.S. Patent 2,489,305 to Miles A. McLellan, filed February 12-, 1948, and issued November 29, 1949.
  • Another object of this invention is to provide a sensing element which is less sensitive to changes in the intensity of light impinging on the pattern to be traced.
  • an apparatus embodying the present invention which comprises photosensitive means responsive to variations in light intensity for causing fluctuations in an electric current proportional to the variations in light intensity upon which an image of the optical field including the line is projected.
  • Opaque means are provided for periodically obstructing the image of the field on the current fluctuating means [for a portion of a cycle of oscillation.
  • Further means are provided which are responsive to the fluctuations in the electric current to maintain the photosensitive means at 21 reference position with respect to the line to be traced.
  • FIGURE 1 is an elevation view of a guidance system embodying this invention
  • FIGURE 2 is a vertical section view of a sensing head for the guidance system of FIGURE 1;
  • FIGURE 3 is a bottom view of the photocell and vibrator assembly shown in FIGURE 4;
  • FIGURE 4 is a vertical section of the photocell and vibrator assembly taken along line 4-4 of FIGURE 3;
  • FIGURE 5 is an enlarged detail view in perspective of the vibrator assembly
  • FIGURE 6 is an enlarged fragmentary view in perspective of the adapter of the assembly shown in FIGURE 4;
  • FIGURE 7 is a schematic of the electrical circuitry of the guidance system
  • FIGURE 8 is a graph showing the vibrator displacement and voltage outputs of the photocell with respect to time, for one embodiment of the invention.
  • FIGURE 8a is a schematic drawing showing the geo- 3,124,691 Patented Mar. 10, 1964 metric conditions for which the curves of FIGURE 8 are representative;
  • FIGURE 9 is a graph showing the vibrator displacement and the voltage output of the photocell with respect to time, for another embodiment of the invention.
  • FIGURE 9a is a schematic drawing showing the geometric conditions for which the curves of FIGURE 9 are representative.
  • FIGURE 10 is a schematic representation of the oscillations of the opaque shade with respect to the photocell which represents another embodiment of this invention.
  • FIGURE 1 shows a guidance system 2% comprising a sensing head 22 rotatably mounted in a frame 24.
  • the sensing head 22 is caused to rotate by a 2-phase servo steering motor 26 fixedly mounted on the frame 24 and having a pinion gear 28 engaging a drive gear 30 on the sensing head 22.
  • the steering motor operates by an electric signal which varies in electrical properties in accordance with the position of the sensing head over a line 31.
  • a tachometer generator 33 is directly coupled to the servo steering motor and serves a purpose which will be hereinafter described.
  • the steering motor 26 also rotates a drive mechanism 32 which is rotatably mounted on the frame 24 by means of a gear 34 in engagement with the pinion 28.
  • the driving mechanism 32 has a wheel 36- which is driven by a separate constant speed motor (not shown) within the drive mechanism.
  • the wheel 36 is in friction engagement with the surface upon which is drawn the line 31 and serves to move the whole system 26 in accordance with the signals of the sensing head 22.
  • the guidance system 20 is fixed- 1y connected to a work tool, such as a cutting torch 37, by means of an arm 38 attached to the frame 24.
  • the torch 37 will, therefore, be caused to trace the same pattern the guidance system is following to cut the desired shaped line in work piece 39.
  • the sensing head 22 which produces the fluctuations in the electric current, comprises, as shown in FIGURE 2', a tubular housing 40 attached to the frame 24 which has an aperture 42 therein abutting a shoulder 44 formed in the housing and secured thereto by appropriate screws (not shown).
  • a tube 48 is journaled within ball bearings 50 in the interior of housing 40.
  • the bearings 50 are secured by clip rings 52 within annular grooves 54 in the bearings adjacent the ends of the housing 40.
  • the gear 30, which is driven by the pinion 28, encircles the upper end of the tube 48 and is secured thereto by convenient means such as set screw 58.
  • a lens assembly 6i which comprises a lens "62 firmly fixed within a lens support 64.
  • the lens assembly 60 is attached to a flange 66 at the lower end of the tube 48 by screws 68 extending through elongated apertures 76 in the lens support and threadedly engage the flange 66.
  • a small plate 72 which is fastened to a flattened portion 74 on the periphery of flange :66 has an adjusting screw 76 passing therethrough and engaging internal threads 78 in the lens support 64 providing for radial adjustment of the lens 62 with respect to the longitudinal axis of the tube 48.
  • a light source 80 is positioned at the lower end of the sensing element head 22 and is fastened to a collar 82 by a plurality of screws 84.
  • the collar 82 has a flange 86 engaged by the bolts 46 which secure it and the light source to the bottom end of the housing 40.
  • the light source 80 comprises a substantially conical shaped hollow member 88 having a plurality of wells 90 circumferentially spaced around the upper portion 92 of the conical member 88 within which are disposed electric lamps 94.
  • An equal plurality of passages 96 extend from the lower end of the conical member 88 and are aligned between the lamps 94 and a focal point on the line 31 to be traced.
  • an assembly comprising a photocell 102, a vibrator assembly 104, and a slip ring and electromagnet subassembly 106, all supported on an adapter 108 fastened to gear 30 by screws 110 extending through a flange 112 on the adapter. It will be noted that the assembly 100 is easily removable from the rest of the sensing head making it readily accessible for maintenance purposes.
  • the slip ring subassembly 106 comprises a cup-shaped member 116, fabricated of an insulating material, to which are attached four slip ring commutators 118.
  • the slip ring subassembly is secured to a tubular portion of the adapter 108 by screws 122 or other suitable fastening means.
  • the photocell 102 is rigidly secured within an aperture in a bar 124 (FIG. 4) disposed within a groove 126 extending diametrically across the bottom of adapter 108.
  • the bar 124 is secured to the adapter 108 by means of screws passing through enlarged apertures 129 in the bar and threadedly engaging the adapter.
  • the photocell 102 has a substantially rectangular sensitive area 127 which is aligned lengthwise with the longitudinal axis of the bar 124.
  • Wires 132 connect the photocell to slip rings 118a and 11012 which are connected by brushes to a circuit to be hereinafter described.
  • the lens 62 near the bottom end of the sensing head 22 is adapted to cast an image of the scanning field 120 (FIG. 2) containing the line 31 on the sensitive area 127 of the photocell 102. The lens is adjusted to view a segment of the line which is displaced a short distance from the axis of rotation of the sensing head.
  • the device its steering sense whereby the steering motor rotates the driving mechanism and the sensing head about their axis pursuant to a sensed transverse deviation of the image of the line from a reference position. It is to be understood that a lens may not be necessary in the sensing head if the photocell is positioned close enough to the line on the work surface. In this case the photocell would be offset from the axis of rotation to give the device its steering sense.
  • An annular light baflle is provided within the tube 48 to prevent unwanted light reflections from reaching the photocell.
  • the vibrator subassembly 104 comprises an arm 134 having a right angle projection 136 (FIG. 2) forming an opaque shade adjacent to the sensitive area 127 on the photocell 102 between it and the lens 62.
  • the opaque shade extends in a direction across the short dimension of the rectangular sensitive area 127 (FIG. 3).
  • arm 134- has a U-shaped fold 140 (FIG. 5) at its other end in the same plane as the opaque shade 136. There is a slot 142 (FIG. 4) in the folded end of the arm which extends from the base 144 through a portion of each of the legs 146 of the U-shaped fold.
  • a flat spring 148 is inserted in the slot 142 forming an aperture 150 with the base and two legs of the U-shaped fold.
  • a U-shaped permanent magnet 152 has its base 154 disposed within said aperture 150 and has its legs 155 extending in a direction opposite from the opaque shade end of the arm 134.
  • the arm 134, flat spring 148 and magnet 152 are suitably secured together to form a rigid assembly by means of an epoxy resin or other suitable fastening means.
  • the ends 156 of flat springs 148 are received in diametrically opposed slots 158 (FIG. 6) at the upper end of the tubular portion 120 of adapter 108.
  • slots 158 There is a second pair of slots 160 immediately adjacent the spring containing slots 160 forming a tongue 162 therebetween.
  • a wedge (not shown) is driven into each of the slots 160 forcing the tongues 162 against the spring ends 156 securing them in rigid engagement within the slots 158.
  • the arm 134 may be caused to angularly vibrate about an axis described by the center of the flat spring 148 to cause the opaque shade 136 to periodically trava erse the image of the scanning field projected on the sensitive area 127 of the photocell 102.
  • the electromagnet 164 To vibrate the arm 134 the permanent magnet 152 is subjected to a fluctuating magnetic field established by an electromagnet 164 (FIGS. 2 and 4) which is connected to an alternating current source through wires 165, and slip rings 1180 and d.
  • the electromagnet 164 has an E-shaped core 166 having legs 167a and b extending towards the legs 155 of the U-shaped permanent ma net 152.
  • a coil 168 is wound around the center leg 16711 of the core 166 which causes a fluctuating magnetic field to be established through the outer legs 167b causing the permanent magnet 152, and hence the arm 134, to vibrate in accordance with the oscillations of the energizing current.
  • the electromagnet is implanted in an epoxy resin 169 or the like within the cup-shaped member 116 to hold it firmly therein.
  • the vibrating assembly is adjusted so that the shade 136 on the arm 134- vibrates with an equal amplitude on either side of a plane which is perpendicular to the sensitive area and includes the center of the scanning field 128.
  • the arm vibrates essentially within a plane which is parallel to the longer dimension of the sensitive area. It will be noted in this particular embodiment that the axis of rotation of the opaque shade is parallel to the plane of the sensitive area. Other configurations are possible, however, as will be described hereinafter.
  • the opaque shade will align itself generally with the image of the line 31 being traced.
  • the variations in the position of the line with respect to the center of vibration causes changes in the electrical signal output of the photocell which directs the steering motor to turn the sensing head toward the line as hereinafter described.
  • the enlarged holes 129 in the bar 124 permit adjustment of the position of the photocell with respect to the vibrating arm to compensate for any irregularities in the photocell to obtain a properly balanced signal.
  • the photocell 102 may be of any well known type with appropriate circuitry.
  • FIGURE 7 shows a circuit usable with a photoresistive-type cell whose resistance varies inversely with light intensity on its sensitive area.
  • the photocell 102 is connected in series with a resistor 170 across a negative DC. voltage.
  • the resistor 172 shown in phantom is not actually included in the circuit but is shown to help describe a certain effect as will be hereinafter described.
  • the vibrator subassembly 104 is schematically shown with the shutter 136 operable to vibrate over the sensitive area 127 of the photocell 102 in response to an alternating current signal applied through transformer 174.
  • a phase adjusting circuit 175 is included in the circuit energizing the vibrator subassembly to compensate for phase shifts in various parts of the electrical circuit.
  • the phase adjusting circuit is not shown in detail as it may be any well known type and does not form a part of this invention.
  • FIGURE 8 shows an example of the kind of signals that may be derived from the output of the photocell connected in a circuit as shown in FIGURE 7.
  • the curves represent voltage signals at the point 178 at the output of the photocell.
  • the width of the projected line 31 is approximately equal to the width of the shade 136 and that the width of the sensitive area 127 of the photocell 102 is larger than three times the width of the shade 136 as shown in FIGURE 8a.
  • the width of vibration is somewhat but not much smaller than the longitudinal dimension of the sensitive area 127.
  • the top curve a in FIGURE 8 shows the shutter amplitude versus time and the relationship is sinusoidal.
  • Curves b, c, d and e are voltage versus time representations.
  • Curve b shows the signal on the cell 102 when the projection of the line 31 is central which coincides with the shade 136 in the condition when the vibrator is not operating.
  • Curves c, d and e show the signals when the line projection 31 is off center by respectively A, /2 and 1 width of the shade 136, as seen in FIG- URE 8a.
  • FIGURE 9 shows an example of a ditferent configuration in which the width of the sensitive area 127 of the photocell 102 is approximately equal to the width of the projected line 31 and the shade 136 as shown in FIGURE 90.
  • the curve a in FIGURE 9 again represents the shutter amplitude versus time and the curves b, c and d represent the same respective deviations as the like lettered curves in FIGURE 8. It should be noted that the indications of the above example are changed in meaning in this case. That is, absence of any signal now indicates that the system is on the line. The presence of the 2 component at its fullest magnitude indicates that there is no line in the scanning field.
  • the fluctuations in the output of the photocell may be passed through an electric circuit and the information derived therefrom made to control the steering motor to make the photocell follow the line.
  • the output of the photocell 102 is fed through two series connected A.C. amplifiers 180 and 182, respectively, to a second harmonic rejector circuit 184, which may take the form of a series resonant circuit to shunt the second harmonic component of the signal to ground.
  • the remainder of the signal is amplified by amplifier 186 and applied to one Winding 188 of the two-phase steering motor 26.
  • the other winding 190 of the motor 26 is connected to the same A.C. source energizing vibrator 104 through a capacitor 192.
  • the capacitor provides a 90 phase shift required to properly phase the signals in the windings of the two-phase type motor.
  • the tachometer generator 34 is directly connected to the shaft of the motor 26 and has one winding 200 connected to the A.C. source.
  • the other winding 202 is connected to the input of amplifier 186 and provides a signal thereto corresponding to the speed of rotation of the motor 26. This signal is in opposition to the input from the preceding circuit leading from the photocell 102.
  • a large output results from the photocell and the amplifiers tend to produce a large output to drive the steering motor at a high speed.
  • the output from the tachometer generator 34 increases and opposes the signal from the photocell thus reducing the output from the amplifier 186. This eflect permits the use of large amplification in the servo loop and reduces overshoot since the maximum amplification of the loop only becomes effective when the speed of the steering motor is near 0.
  • An alarm circuit 204 is connected to the output of amplifier and provides a warning when there is no line in the scanning field image projected on the photocell. It also turns off the A.C. power to the feed motor 205 which drives the wheel 36 in the driving mechanism 32.
  • the alternating current signal from the amplifier is converted to direct current by a conventional rectifier 266 whose output is connected through amplifier 2% to the energizing coil 210 of relay 212.
  • the coil 210 when energized, operates the contacts 194 and 196.
  • the contacts 194 in series with the feed motor are normally open.
  • Contacts 196 which are serially connected with lamp 1% across the A.C. feed source, are normally closed.
  • the particular warning circuit 2% shown in FIGURE 7 presumes, of course, a configuration of the photocell and vibrator shown and described in FIGURES 8 and 8a. If the configuration of FIGURES 9 and 9a is used, the alarm circuit must be modified to cause the power to the motor to be cut oh and the warning light energized when the signal comprises a maximum 2]- component. When there is no second harmonic component at the output of the amplifier 130 it is indicative that the photocell is over a line, power must be on with the warning light shut off.
  • the vibrator assembly might be of a type, as shown in FIGURE 10, in which the opaque shade 136 angularly vibrates about an axis 22% which is perpendicular to the plane of the sensitive area 127 of the photocell, and with equal amplitude on either side of a plane perpendicular to the plane of the sensitive area and intersecting the center of the scanned field.
  • the vibrations are of equal amplitude on either side of the center plane, the angular vibration has no adverse effect on the signal produced by the photocell as it encounters the line.
  • the operation of the device may be improved when the scanning headis provided with a photocell having a relatively long photosensitive area compared to the peak to peak amplitude of the opaque shade vibrations. A relatively large area of the photocell will then be illuminated without interruption. This area of the photocell does not contribute to the signal but forms a resistive load 011 the circuit which may be thought of as a variable resistance in parallel with the photocell 1&2.
  • the resistor 172 shown in phantom in FIGURE 5, represents this resistive load.
  • the efiective shunting resistance represented as resistance 172, loading the circuit is increased so that it counteracts the reduction in sensitivity. It has been found that the sensitivity of a photo element having a relatively wide sensitive area is almost independent of small variation of the voltage of the light source.
  • the sensing head hereinbefore described is not limited to use with line tracing systems but may be used in many other applications wherein it is necessary to determine the position of a line.
  • it may be useful as a position determining element in precision gauging equipment such as line standard comparators. It could also be adapted for use as a sensing element in wire gauging instruments or for remote observation of the relative position of machine tool elements with respect to a measuring scale. It is, therefore, intended that the invention should not be limited to the embodiments hcreinbefore disclosed, but should embrace all of the embodiments which may be included within the framework of the appended claims.
  • a head for a system for scanning a line comprising photosensitive means having a sensitive area positioned to have an image of the scanning field containing the line cast thereon, the length of the sensitive area in a direction transverse to the line being equal to or greater than the width of the image of the line, continuous opaque means disposed between the sensitive area and the line, and means for oscillating said opaque means essentially transversely to the line for periodically obstructing the image of the line on the sensitive area, said opaque means oscillating with equal amplitude across a plane perpendicular to the sensitive area and containing the center of the scanning field.
  • a head for a system for scanning a line comprising photosensitive means having an elongated sensitive area positioned to have an image of the line cast on said sensitive area transverse to the areas longest dimension, totally opaque means disposed between said sensitive area and the line, and means for angularly oscillating said opaque means transversely to the line for periodically obstructing the image on the photosensitive means, the axis of the angular oscillation being positioned within a plane perpendicular to and intersecting said sensitive area.
  • a scanning head for a system for tracing a line comprising a photocell having an elongated rectangular sensitive area, said photocell positioned to have an image of the scanning field containing said line cast upon said sensitive area, an arm having a continuous opaque portion positioned between said sensitive area and the scanning field and extending transversely across said rectangular sensitive area, said opaque portion having a width approximately equal to the image of the scanned line, and means for vibrating said arm to cause said opaque portion to oscillate in a direction along the longer dimension of the rectangular sensitive area.
  • a system for scanning a line comprising a scanning head, said scanning head comprising photosensitive means having a sensitive area positioned to have an image of the scanning field containing the line cast thereon, said photosensitive means adapted to cause fluctuations in an electric signal proportional to variations in light intensity, the length of the sensitive area in a direction transverse to the line being substantially greater than the width of the image of the line, opaque means disposed between the sensitive area and the line, means for oscillating said opaque means essentially transversely to the line for periodically obstructing the image of the line on the sensitive area, said opaque means oscillating with equal amplitude across a plane perpendicular to said sensitive area and containing the center of the scanning field, means for selecting from the fluctuating signal output of the scanning head an odd harmonic component of the oscillation frequency, said odd harmonic component having the property of reversing its phase as the line moves from one side of said plane to the other, and means synchronized with the oscillations of said opaque means and recipient of said odd harmonic component for producing different electrical outputs for the two opposite
  • a system for scanning a line comprising a scanning head, said scanning head comprising photosensitive means having a sensitive area positioned to have an image of the scanning field containing the line cast thereon, said photosensitive means adapted to cause fluctuations in an electric signal proportional to variations in light intensity, the length of the sensitive area in a direction transverse to the line being approximately equal to the width of the image of the line, opaque means disposed between the sensitive area and the line, means for oscillating said opaque means essentially transversely to the line for periodically obstructing the image of the line on the sensitive area, said opaque means oscillating with equal amplitude across a plane perpendicular to said sensitive area and containing the center of the scanning field, means for selecting from the fluctuating signal output of the scanning head an odd harmonic component of the oscillation frequency, said odd harmonic component having the property of reversing its phase as the line moves from one side of said plane to the other, and means synchro nized with the oscillations of said opaque means and recipient of said odd harmonic component for producing different electrical outputs for the
  • the system as claimed in claim 13 comprising in addition means for selecting from the fluctuating output of the scanning head an even harmonic component of the oscillation frequency, and means in receipt of said even harmonic signal for producing another electrical output whereby the receipt of said even harmonic signal indicates the absence of a line within the scanning field.
  • said oscillating means comprises an arm having a right angle projection forming said opaque means at one end thereof, a U-shaped fold at the other end of said arm in the same plane as said right angle projection, said arm having a slot extending from the base of said U-shaped fold through a portion of each leg of said U-shaped fold, a flat spring received in said slot and forming an aperture with th base and legs of said U-shaped fold; a U-shaped permanent magnet having its base received in said aperture, means for fastening said arm, flat spring and magnet rigidly together, an E-shaped electromagnet rigidly mounted with respect to said permanent magnet and magnetically coupled thereto, and means for rigidly fastening the ends of said flat spring.
  • said last mentioned means comprises a tubular member having a pair of oppositely disposed slots at one end, said slots receiving the ends of said flat spring, said tubular member having a second pair of oppositely disposed slots at its one end immediately adjacent to said first pair of slots forming a pair of tongues therebetween, and Wedge means within said second pair of slots to force said tongues tightly against the ends of the springs.
  • a vibrating assembly for use with a scanning head in a line tracing system comprising photoelectric means positioned to have an image of the line cast thereupon, and opaque means driven by said vibrating assembly for periodically obstructing the image of the line upon said photoelectric means; said vibrating means comprising an arm having a right angle projection forming said opaque means at one end thereof, a U-shaped fold at the other end of said arm in the same plane as said right angle projection, said arm having a slot extending from the base of said U-shaped fold through a portion of each leg of said U-shaped fold, a flat spring received in said slot forming an aperture with the base and legs of said U-shaped fold, a U-shaped permanent magnet having its base received in said aperture, means for fastening said arm, fiat spring and magnet rigidly together, an E-shaped electromagnet rigidly mounted with respect to said perma nent magnet and magnetically coupled thereto and means for rigidly fastening the ends of said flat spring.
  • said last mentioned means comprises a tubular member having a pair of oppositely disposed slots at one end, said slots receiving the ends of said flat spring, said tubular member having a second pair of oppositely disposed slots at its one end immediately adjacent to said first pair of slots forming a pair of tongues therebetween and wedge means within said second pair of slots to force said tongues tightly against the ends of the springs.
  • the vibrating assembly as claimed in claim 18 comprising in addition a bar adjustably mounted across the other end of said tubular member and rigidly supporting said photoelectric means within operable proximity of said right angle projection.
  • a head for a system for scanning a line comprising photosensitive means having a sensitive area positioned to have an image of the scanning field containing the line cast thereon, the length of the sensitive area in a direc tion transverse to the line being equal to or greater than the width of the image of the line, continuous opaque means disposed between the sensitive area and the line, and means for oscillating said opaque means essentially transversely to the line for periodically obstructing the image of the line on the sensitive area.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Artificial Intelligence (AREA)
  • Computer Hardware Design (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Control Of Position Or Direction (AREA)
US5692060 1960-09-19 1960-09-19 light sensitive line tracing apparatus Expired - Lifetime US3124691A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US5692060 US3124691A (en) 1960-09-19 1960-09-19 light sensitive line tracing apparatus
DEST18108A DE1232243B (de) 1960-09-19 1961-07-22 Abtastvorrichtung fuer ein Spurverfolgungsgeraet
NL268792A NL120793C (nl) 1960-09-19 1961-08-31 aftastinrichting voor een lijnvolgmechanisme
FR873500A FR1301550A (fr) 1960-09-19 1961-09-18 Dispositif d'exploration pour appareil devant suivre une ligne ou un tracé
GB33389/61A GB995421A (en) 1960-09-19 1961-09-18 Line tracing apparatus
NL6514970A NL6514970A (cs) 1960-09-19 1965-11-17

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US5692060 US3124691A (en) 1960-09-19 1960-09-19 light sensitive line tracing apparatus

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US3124691A true US3124691A (en) 1964-03-10

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US5692060 Expired - Lifetime US3124691A (en) 1960-09-19 1960-09-19 light sensitive line tracing apparatus

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US (1) US3124691A (cs)
DE (1) DE1232243B (cs)
FR (1) FR1301550A (cs)
GB (1) GB995421A (cs)
NL (2) NL120793C (cs)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3301543A (en) * 1963-01-30 1967-01-31 Hancock & Co Eng Ltd Oxygen jet cutting machines
US3312562A (en) * 1963-04-30 1967-04-04 Union Carbide Corp Method and apparatus for cutting and marking metal plate
US3354320A (en) * 1964-08-31 1967-11-21 Hugh L Dryden Light position locating system
US3446969A (en) * 1965-07-22 1969-05-27 Messer Griesheim Gmbh Photoelectric tracing control mechanism employing an electrical function transmitter
US3566129A (en) * 1969-04-28 1971-02-23 Stewart Warner Corp Pattern catching in a photoelectric pattern contour tracing system
US3855446A (en) * 1972-11-17 1974-12-17 V Kotova Device for directing the movement of welding electrode along the butt of joining parts
JPS50119649A (cs) * 1974-03-04 1975-09-19
US4172587A (en) * 1977-09-14 1979-10-30 Messer Griesheim Gmbh Flame cutting machine

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Publication number Priority date Publication date Assignee Title
GB2134263B (en) * 1982-11-09 1986-02-19 Derek Harry Graddon Redman Discontinuity in metals sensing system

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US1631021A (en) * 1925-04-15 1927-05-31 Dowling John Joseph Thermionic indicating means responsive to light variations
US2208420A (en) * 1938-06-08 1940-07-16 Westinghouse Electric & Mfg Co Registration control system
US2489305A (en) * 1948-02-12 1949-11-29 Miles A Mclennan Photoelectric curve following device
US2791696A (en) * 1952-02-23 1957-05-07 Rca Corp Calibration method and device therefor
US2795736A (en) * 1953-11-04 1957-06-11 Burroughs Corp Automatic headlight dimmer
US2816283A (en) * 1956-03-30 1957-12-10 Rca Corp Semiconductor null detector
US2899564A (en) * 1959-08-11 Single-track scanning type dimmer
US3017801A (en) * 1957-11-29 1962-01-23 Ingber Oscar Henri Device for measuring the width or diameter of fixed or movable tapes and wires
US3037888A (en) * 1958-10-03 1962-06-05 Union Carbide Corp Method of cutting

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FR986015A (fr) * 1949-02-28 1951-07-26 Modernisation Ind Machine à graver et à fabriquer les pochoirs

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US2899564A (en) * 1959-08-11 Single-track scanning type dimmer
US1631021A (en) * 1925-04-15 1927-05-31 Dowling John Joseph Thermionic indicating means responsive to light variations
US2208420A (en) * 1938-06-08 1940-07-16 Westinghouse Electric & Mfg Co Registration control system
US2489305A (en) * 1948-02-12 1949-11-29 Miles A Mclennan Photoelectric curve following device
US2791696A (en) * 1952-02-23 1957-05-07 Rca Corp Calibration method and device therefor
US2795736A (en) * 1953-11-04 1957-06-11 Burroughs Corp Automatic headlight dimmer
US2816283A (en) * 1956-03-30 1957-12-10 Rca Corp Semiconductor null detector
US3017801A (en) * 1957-11-29 1962-01-23 Ingber Oscar Henri Device for measuring the width or diameter of fixed or movable tapes and wires
US3037888A (en) * 1958-10-03 1962-06-05 Union Carbide Corp Method of cutting

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3301543A (en) * 1963-01-30 1967-01-31 Hancock & Co Eng Ltd Oxygen jet cutting machines
US3312562A (en) * 1963-04-30 1967-04-04 Union Carbide Corp Method and apparatus for cutting and marking metal plate
US3354320A (en) * 1964-08-31 1967-11-21 Hugh L Dryden Light position locating system
US3446969A (en) * 1965-07-22 1969-05-27 Messer Griesheim Gmbh Photoelectric tracing control mechanism employing an electrical function transmitter
US3566129A (en) * 1969-04-28 1971-02-23 Stewart Warner Corp Pattern catching in a photoelectric pattern contour tracing system
US3855446A (en) * 1972-11-17 1974-12-17 V Kotova Device for directing the movement of welding electrode along the butt of joining parts
JPS50119649A (cs) * 1974-03-04 1975-09-19
US4172587A (en) * 1977-09-14 1979-10-30 Messer Griesheim Gmbh Flame cutting machine

Also Published As

Publication number Publication date
NL120793C (nl) 1966-05-16
FR1301550A (fr) 1962-08-17
NL6514970A (cs) 1966-01-25
GB995421A (en) 1965-06-16
DE1232243B (de) 1967-01-12

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