US2736431A - Sheet pin hole detector - Google Patents

Sheet pin hole detector Download PDF

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Publication number
US2736431A
US2736431A US272471A US27247152A US2736431A US 2736431 A US2736431 A US 2736431A US 272471 A US272471 A US 272471A US 27247152 A US27247152 A US 27247152A US 2736431 A US2736431 A US 2736431A
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United States
Prior art keywords
light
sheets
photosensitive device
movement
sheet
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Expired - Lifetime
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US272471A
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English (en)
Inventor
William E Coleman
George H Rendel
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United States Steel Corp
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United States Steel Corp
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Publication date
Priority to BE516718D priority Critical patent/BE516718A/xx
Application filed by United States Steel Corp filed Critical United States Steel Corp
Priority to US272471A priority patent/US2736431A/en
Priority to GB28743/52A priority patent/GB708513A/en
Priority to FR1075253D priority patent/FR1075253A/fr
Application granted granted Critical
Publication of US2736431A publication Critical patent/US2736431A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
    • G01N21/892—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the flaw, defect or object feature examined
    • G01N21/894—Pinholes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S209/00—Classifying, separating, and assorting solids
    • Y10S209/941—Item carrying bridge raisable to expose discharge opening

Definitions

  • This invention relates to a pin hole detector and more particularly to a detector for detecting and classifying thin sheets of material such as steel for tin plate.
  • small perforations known as pin holes are formed in the strip.
  • the strip is inspected for these pin holes by means of apparatus such as shown in Chamberlin et al. Patent No. 2,229,638.
  • the apparatus therein described was designed and is suitable for inspecting strip, but it and other such apparatus are not suitable for detecting pin holes in individual sheets. Therefore, the common method of inspecting individual sheets is by visual inspection and manual handling of each sheet. Such method is slow and expensive.
  • Figure l is a schematic drawing of the inspection line with the detecting and classifying control incorporated therein;
  • Figure 2 is a sectional elevation taken on the line lI-Il of Figure l;
  • Figure 3 is a view showing the voltage wave forms in part of the apparatus.
  • the reference numeral 2 indicates a pile of sheets which are to be inspected.
  • the sheets S are fed from the pile 2 by means of a feeder 4 such as the well known Dexter feeder to a motor driven conveyor belt 6.
  • The' sheets S pass from the conveyor 6 to a second conveyor 8.
  • the prime sheets pass over a defiector 10 to another motor driven belt .conveyor 12 and then to the prime sheet pile i4.
  • the defective sheets pass from the conveyor 8 below the deliector 10 to a belt conveyor 16 and then to a salvage pile 18.
  • the conveyors 6 and 8 are spaced apart a distance less than the length of the lshortest sheet to' be inspected. Side guides 20 for the sheets are provided between the conveyors 6 and 8'.
  • a source of light 22 is provided above the path of travel of the sheets S between the conveyors 6 and S and a second source or" light 24 is provided on the same side of the path of travel of the sheets S toward the conveyor 8 from the light source 22.
  • the light sources 22 and 24 provide light beams 26 and 28 respectively.
  • a group of photoelectric cells 30 are located directly below the light source 22 and below the path of travel of the Sheets S.
  • a pair of photocells 32 connected in series are also located below the light source 22.
  • the photocells 30 and 32 are mounted in a common housing '34.
  • the photocells 30 are connected to an amplifier 36 which is of the type that puts out a negative pulse followed by a positive pulse each time light strikes one or more yof the photocells 30.
  • a negative and positive pulse will occur at the output of the amplifier 36 each time a hole is detected in the sheet and each time the trailing end of the'sheet exposes the photocells 30 to lthe light.
  • a small hole will provide a very ⁇ small input pulse to the amplifier whereas the great amount of light which strikes the photocells 30 when the trailing rend of the .sheet passes the light beam 26 results in Va very 'large input pulse to the amplifier 36.
  • the amplifier 36 is designed to limit the output of the large impulse to a value not appreciably greater than the impulse from a very small hole. As shown, the amplifier 36 consists of a D. C. amplifier 3S and A. C. amplifiers 4t) and 42.
  • the first stage amplifier 38 is a conventional electron tube amplifier directly coupled to the photocells 30.
  • the amplifier Sti is coupled to the second stage amplifier 40 through a differentiator circuit consisting of a capacitor 44 and res-istor 46.
  • the amplifier 40 is a single electron tube amplifier operating with zero grid bias and is coupled to the third stage amplifier 42 through a normal long time constant coupling circuit consisting of a capacitor 48 and resistor Sti.
  • Amplifier 42 is also a single electron tube amplifier and is biased approximately at cut off.
  • the output of amplifier 42 is connected to a resistor 52 through a differentiating circuit consisting of a capacitor 54 and resistor 56. Power for the amplifiers 38, 46 and 42 is supplied by means of a D. C. power source 58.
  • the voltage wave forms at points A, B, C, D, E and F are shown in Figure 3. These wave forms are drawn to show the voltage variations in the circuit when one sheet containing a hole approximately in the center passes through light beam 26. When the leading end of the sheet crosses light beam 26 the input voltage to amplifier 3S drops as a result of light being removed from photocells 3i? as shown in wave form A. When the hole passes light beam 26 a small positive pulse occurs and when the trailing edge clears the light beam 26, the voltage again rises. These voltage variations are amplified and reversed in amplifier 33 and the output at point B is shown in wave form B. This voltage variation is impressed on the differentiator circuit consisting of capacitor 44 and resistor 46 and results in the wave form C at point C.
  • the output voltage of amplifier 4th is applied to amplifier 42 which is adjusted to operate with sufficient grid bias to approximately cut off its plate current when no input pulse is bei-ng applied.
  • the small remaining negative pulse of the leading edge in wave form D is not passed by ampliier 42.
  • the positive pulses for the hole vand the trailing end are amplified and the output thereof is that shown in wave form E.
  • the hole pulse is now approximately of the same amplitude as that of the trailing end of the sheet.
  • the output of amplifier 42 is applied to the differentiator circuit consisting of capacitor 54 and resistance 56. This provides an output voltage as shown in wave form F.
  • This voltage is applied through resistor 52 to the grid 60G of a gas tube 6i) and to the plate 621J of a vacuum tube 62.
  • the voltage produced at the grid 62G as a result of light striking the two photocells 32 is shown in wave form G.
  • the result of the voltage at point F and the voltage at point G is shown as wave form H at the plate 62P.
  • the photocells 32 are connected to voltage amplifier Y64 which in turn is connected to a tube 66.
  • the tube -66 may be part of the amplifier 64 but is shownvseparately in order to clarify the description. 'LightA Striking' both Ynormally highly conducting. ⁇ in the connection between the D. C. power source 76 and Q ,r of photocells 32 will cause a drop in voltage on grid 66G.
  • the use of two photocells is not essential, but two are used instead of one to prevent a large hole over one photocell from blanking out the signal in the manner described below.
  • the amplifier 64 and tube 66 are supplied with power from a D. C. power source 68 which has its positive side grounded.
  • Tube 66 is normally conducting, that is, current exists between its plate and cathode and the plate 66P is at a potential below ground because of the drop in resistor 70 connected in the circuit.
  • the plate 66P is directly connected to the grid 62G.
  • the tube 60 is normally held non-conducting by a positive bias on its cathode 60C which is obtained by the voltage divider consisting of resistors 72 and 74 which obtain power from a D. C. power source 7 6.
  • a resistance 78 is connected between the positive terminal of D. C..power source 76 and the plate 691.
  • the resistance 78 is connected to the terminals of a voltage amplier 80 which is connected to a photoelectric cell 82 which receives light from the light source 24.
  • a voltage amplier 80 When there is a drop in voltage across the resistor 74 it is transmitted through a capacitor 84 and appears as a negative pulse across resistor 86 and on grid 88G of a vacuum tube 88 which operates with no grid bias so that it is A resistor 90 is connected the plate 88P.
  • the tube 88 will not be affected by a positive pulse but the negative pulse which occurs when light strikes photocell 82 will reduce the current in the tube 88 and resistor 90 to permit the potential of plate 881 to rise, thus providing a short positive pulse which is transmitted to the pulse-lengthener 92.
  • the pulselengthener 92 may be a conventional one-shot cathode coupled multivibrator triggered by a. triode ampliiier such as shown in the copending application to Coleman, Serial No. 133,343, now abandoned, filed December 16, 1949 and its continuation-in-part application, now Patent No. 2,655,620, dated October 13, 1953.
  • Pulse-lengthener 92 provides an output pulse of desired duration which controls a gas tube switch 94 or similar device, which in turn applies alternating current from A. C. power source 96 to a solenoid 98 which is connected to operate the gate 10.
  • the gas tube 60 will conduct until the trailing end of the sheet containing the hole passes through light beam 28, thus permitting light to strike photocell 82.
  • This negative pulse is of suicient amplitude to drive the potential of plate 60P below the potential of cathode 60C momentarily and thus extinguish the tube 60 and reduce the potential drop across resistor 74.
  • This drop in voltage across resistor 74 is transmitted through the capacitor 84 and appears as a negative pulse across resistor 86 and on grid SSG.
  • tube 88 Since tube 88 operates with no grid bias, it is normally highly conducting and the positive pulse occurring on its grid when tube 60 fires has no appreciable effect but the negative pulse reduces the current in tube 88 and resistor 90 and permits the potential of plate 881 to rise, thus providing a short positive pulse into pulse lengthener 92 which provides an output pulse to operate the gas tube switch 94 and apply power to operate solenoid 98. This raises the deector 10 to cause the imperfect sheet to pass over the conveyor 16 into pile 18. As soon as the pulse from pulse lengthener 92 is extinguished the gate 10 will return to its normal position. y While one embodiment of our invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.
  • Apparatus for detecting pin holes in moving sheets comprising means for moving the sheets along a normal path of movement, a source of light on one side of the normal path of movement of said sheets, a photosensitive device on the other side of the normal path of movement constructed and arranged for detecting pin holes, means operable by light falling on said photosensitive device for directing sheets with a pin hole therein out of the normal path of movement of said sheets, a second photosensitive device operable by light from said rst light source located adjacent the Iirst photosensitive device constructed and arranged for preventing operation of said means when there is no sheet between the light and said photosensitive devices, a second source of light on the exit side of said rst source, a photosensitive device on the other side of the normal path of movement operable by said second light source, and means operable by light falling on said last named photosensitive device for controlling start of operation of said first named means.
  • Apparatus for detecting pin holes in moving sheets comprising a conveyor system for said sheets, a prime sheet piler, a defective sheet piler, said sheets normally traveling to said prime sheet piler, a dei'lector for directing sheets to the defective sheet piler, a source of light on one side of the path of movement of said sheets, a photosensitive device on the other side of the path of movement constructed and arranged for detecting pin holes, means operable by light falling on said photosensitive device for operating said deflector to direct sheets with pin holes 5 therein to the defective sheet piler, and a second photosensitive device operable by light from said nist light source located adjacent the first photosensitive device constfucted and arranged for preventing operation of said means when there is no sheet between the light and said photosensitive devices, a second source of light on the exit side of said first source, a photosensitive device on the other side of the path of movement operable by said second light source, and means operable by light falling on said last named photosensitive device for controlling start of operation of said first named
  • Apparatus for detecting pin holes in moving sheets comprising means for moving the sheets along a normal path of movement, a source of light on one side of the normal path of movement of said sheets, a photosensitive device on the other side of the normal path of movement for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, means connected to said photosensitive device for amplifying an impulse therefrom and changing it to a positive and negativ'e pulse, an electronic tube becoming conductive by a positive impulse from said'last named means, means operable by said electronic tube rfor directing sheets with a pin hole therein out of the normal path of movement of said sheets, a second photosensitive device adjacent the first photosensitive device, a second electronic tube operable by an impulse from said second photosensitive device, and means connecting the plate of the second tube to the output of said amplifying means to shor't the output of said amplifying mea-ns 'and prevent operation of said first tube when there is-no sheet between the light and said photosensitive device.
  • Apparatus for detecting pin holes in moving Sheets comprising means for moving kthe sheets along a normal path of movement, a source of ylight 'on 'one side 'of the normal path of movement of said sheets, a photosensitive device on the'other side ofthe normal path of movement for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, a voltage -ampliiier connected to said photosensitive device, an electronic tube becoming conductive by an impulse'from said voltage amplifier, means operable by said electronic -tube for directing sheets with a pin hole therein out of the normal path of movement of said sheets, means for preventing operation of said tube when there is no sheet between the light and said photosensitive device, a second source of light on the eXit side of said first source, a photosensitive device on the other side of the path of movement operable by said second light source, and lmeans operable by light falling on said last named photosensitive device 7 for controlling start of operation 'of vsaid first named means.
  • Apparatus for detecting pinholes in moving sheets ycomprising means for moving the sheets 'along a normal path of movement, a source of light on one side of the normal path of movement of said sheets, a photosensitive device on the other side of the normal path of movement for detecting pin holes, said lphotosensitive device generating an electric impulse when .light falls thereon, a voltage amplifier connected to said first named photosensitive device, an electronic tube becoming conductive by an impulse from said voltage amplifier, means 'operable by said electronic tube for directing sheets with a pin hole therein out of the normal path of movement k of said sheets, a second photosensitive device adjacent the first photosensitive device, a second electronic tube operable by an impulse from said second photosensitive device for preventing operation of said first tube when there is no sheet between the light and said photosensitive device, a second source of light on 'the vexit Aside of said first source, a photosensitive device on the other side of the normal path of movement operable by said second light source, and
  • Apparatus for detectiug'pin holes in moving' sheets comprising means for moving the sheets along a normal path of movement, a source of ylight on one side of the normal path of movement of said sheets, a photosensitive device on the other side of the normal path of movement for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, means connected to said photosensitive device for amplifying an impulse therefrom and changing it to a positive and negative pulse, an electronic tube becoming conductive by a positive impulse from said last named means, means operable by said electronic tube for directing sheets with a pin hole therein out of the normal path of movement of said sheets, a second photosensitive device adjacent the first photosensitive device, a second electronic tube oper'- able by an impulse from said second photosensitive device, means connecting the plate of the second tube to the output of said amplifying means to short the output of said amplifying means and prevent operation of said first tube when there is no sheet between the light and said photosensitive device, a second source of light on the exit side of said first source
  • Apparatus for detecting pin holes in moving sheets comprising a conveying system for said sheets, a prime sheet piler, a defective sheet piler, said sheets normally traveling to said prime sheet piler, a defiector for directing sheets to the defective sheet piler, a source of light on one side of the path of movement of said sheets, a photosensitive device on the other side of the path of movement for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, mea-ns connected to said photosensitive device for amplifying an impulse therefrom and changing it to a positive and negativemodule, an electronic tube operable by a positive impulse from said last named means, means operable by said electronic tube for operating said deflector to direct sheets with pin holes therein to the defective sheet piler, a second photosensitive device adjacent the first photosensitive device, a second electronic tube operable by an impulse from said second photosensitive device, and means connecting the plate of the second tube to the output of said amplifying means to short the output of said amplifying means and prevent operation of said
  • Apparatus for detecting lp'iri holes -in 'moving sheets comprising a conveying system 'for said sheets, 'a -prime sheet piler, a defective sheet piler, said sheets normally traveling to said prime sheet piler, a deliector' for vdirecting sheets to the defective sheet piler, a source of light-'on one side of the path of movement of said sheets, aphotosensitive device on the other side of the path of Vmovement for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, a voltage amplifier connected to said photosensitive ⁇ device, an electronic tube operable byY an impulse from'v said voltage amplifier, means operable by said electronic tube for operating said deliector to direct sheets with pin 4holes therein to the defective sheet piler, means for preventing operation of said tube when there is no sheet between the light and said photosensitive device, a second 'source of light on the exit side of said'first source, aphotosensitive device on the other side of the path of movement oper
  • Apparatus vfor detecting pin holes in moving sheets comprising a conveying system for said sheets, aprirne ⁇ sheet piler, a defective sheet piler, said sheets' normally traveling to said prime sheet piler, a detiector for direct.-4
  • atea-131 ing sets to the defective shet piler, a source of light on onel side of the path of movement of said sheets, a photosensitive device on the other side of the path of movement constructed and arranged for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, a voltage amplifier connected to said photosensitive device, an electronic tube operable by an impulse from said voltage amplifier, means operable by said electronic tube for operating said deflector to direct sheets with pin holes therein to the defective sheet piler, a second photosensitive device adjacent the first photosensitive device, a second electronic tube operable by an impulse from said second photosensitive device for preventing operation of said first tube when there is no sheet between the light and said photosensitive device, a second source of light on the exit side of said first source, a photosensitive device on the other side of the path of movement operable by said second light source, and means operable by light falling on said last named photosensitive device for controlling start of operation of said first named means.
  • Apparatus for detecting pin holes in moving sheets comprising a conveying system for said sheets, a prime sheet piler, a defective sheet piler, said sheets normally traveling to said prime sheet piler, a defiector for directing sheets to the defective sheet piler, a source of light on one side of the path of movement of said sheets, a photosensitive device on the other side of the path of movement for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, means connected to first named photosensitive device for amplifying an impulse therefrom and changing it to a positive and negative pulse, an electronic tube operable by a positive impulse from said last named means, means operable by said electronic tube for operating said deliector to direct sheets with pin holes therein to the defective ysheet piler, a second photosensitive device adjacent the first photosensitive device, a second electronic tube operable by an impulse from said second photosensitive device, means connecting the plate of the second tube to the output of said amplifying means to short the output of said amplifying means and prevent operation of said first tube when
  • Apparatus for detecting pin holes in moving sheets comprising means for moving the sheets along a normal path of movement, a source of light on one side of the normalv path of movement of said sheets, a photosensitive device on the other side of the normal path of movement constructed and arranged for detecting pin holes, means operable by light falling on said photosensitive device for directing sheets with a pin hole therein out of the normal path of movement of said sheets, a second photosensitive device operable by light from said first light source located adjacent the first photosensitive device constructed and arranged for preventing operation of said means when there is no sheet between the light and said photosensitive devices, and means operable by an end of the sheet being inspected for controlling start of operation of said first named means.
  • Apparatus for detecting pin holes in moving sheets comprising a conveying system for said sheets, a prime sheet piler, a defective sheet piler, said sheets normally traveling to said prime sheet piler, a detiector for directing sheets to the defective sheet piler, a source of light on one side of the path of movement of said sheets, a photosensitive device on the other side of the path of movement constructed and arranged for detecting pin holes, means operable by light falling on said photosensitive device for operating said deector to direct sheets with pin holes therein to the defective sheet piler, a second photosensitive device operable by light from said first light source located adjacent the first photosensitive device constructed and arranged for preventing operation of said means when there is no sheet between the light and said photosensitivedevices, and means operable by an end of the sheet being inspected for controlling start of operation of said first named means.
  • Apparatus for detecting pin holes in moving sheets comprising means for moving the sheets along a normal path of movement, a source of light on one side of the normal path of movement of said sheets, a photosensitive device on the other side of the normal path of movement constructed and arranged for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, a voltage amplifier connected to said photosensitive device, an electronic tube operable by an impulse from said voltage amplifier, means operable by said electronic tube for directing sheets with a pin hole therein out of the normal path of movement of said sheets, means for preventing operation of said tube when there is no sheet between the light and said photosensitive device, and means operable by an end of the sheet being inspected for controlling start of operation of said first named means.
  • Apparatus for detecting pin holes in moving sheets comprising means for moving the sheets along a normal path of movement, a source of light on one side of the normal path of movement of said sheets, a photosensitive device on the other side of the normal path of movement constructed and arranged for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, a voltage amplifier connected to said first named photosensitive device, an electronic tube operable by an impulse from said voltage amplifier, means operable by said electronic tube for directing sheets with a pin hole therein out of the normal path of movement of said sheets, a second photosensitive device adjacent the first photosensitive device, a second electronic tube operable by an impulse from said second photosensitive device for preventing operation of said first tube when there is no sheet between the light and said photosensitive device, and means operable by an end of the sheet being inspected for controlling start of operation of said first named means.
  • Apparatus for detecting pin holes in moving sheets comprising means for moving the sheets along a normal path of movement, asource of light on one side of the normal path of movement of said sheets, a photosensitive device on the other side of the normal path of movement for detecting pin holes, said photosensitive device generating an electric impulse when light falls thereon, an electronic tube operable by an impulse from said photosensitive device, means operable by said electronic tube for directing sheets with a pin hole therein out of the normal path of movement of said sheets, a second photosensitive device operable by light from said first light source located adjacent the first photosensitive device, means for connecting the output of said second photosensitive device to said tube for preventing operation thereof when there is no sheet between the light and said second photosensitive device, means for delaying the action of the impulse from said first photosensitive device on said tube, and means operable by an end of the sheet being inspected for controlling the start of operation of said first named means.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Controlling Sheets Or Webs (AREA)
  • Control Of Combustion (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
US272471A 1952-02-19 1952-02-19 Sheet pin hole detector Expired - Lifetime US2736431A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BE516718D BE516718A (pt) 1952-02-19
US272471A US2736431A (en) 1952-02-19 1952-02-19 Sheet pin hole detector
GB28743/52A GB708513A (en) 1952-02-19 1952-11-14 Sheet pin hole detector
FR1075253D FR1075253A (fr) 1952-02-19 1953-01-05 Dispositif pour détecter les trous dans les tôles et autres produits en feuilles

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US272471A US2736431A (en) 1952-02-19 1952-02-19 Sheet pin hole detector

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US2736431A true US2736431A (en) 1956-02-28

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BE (1) BE516718A (pt)
FR (1) FR1075253A (pt)
GB (1) GB708513A (pt)

Cited By (13)

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US2917168A (en) * 1955-12-13 1959-12-15 Time Inc Mechanism for separating bound and unbound books
US2933185A (en) * 1955-05-11 1960-04-19 United States Steel Corp Method and apparatus for classifying sheets according to length
US2977114A (en) * 1956-08-06 1961-03-28 Pitney Bowes Inc Document feeding apparatus
US2990953A (en) * 1958-10-21 1961-07-04 Mosaic Tile Company Machine for detecting cracked ceramic tiles
US3017992A (en) * 1958-03-24 1962-01-23 Bartelt Engineering Co Inc Machine for classifying packages according to weight
US3035694A (en) * 1957-04-09 1962-05-22 Int Standard Electric Corp Article sorting control apparatus
US3219184A (en) * 1962-04-26 1965-11-23 Dolph V Van Laanen Sorting apparatus
US3239814A (en) * 1962-02-14 1966-03-08 Lionel Electronics Lab Inc Document testing and identification system
US3307696A (en) * 1965-05-10 1967-03-07 Owens Illinois Inc Inspecting hypodermic syringe cartridges and the like
US3351196A (en) * 1965-11-22 1967-11-07 Dolph V Van Laanen Defective sheet sorting apparatus
US3583562A (en) * 1969-01-07 1971-06-08 Coe Mfg Co The Methods of and apparatus for stacking veneer sheets
US4727991A (en) * 1985-11-01 1988-03-01 Fleetwood Systems, Inc. Scroll strip conveyor system
CN110508499A (zh) * 2019-08-29 2019-11-29 江苏盛矽电子科技有限公司 一种自动分离式丝印网版检测装置及其检测方法

Families Citing this family (1)

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US2881919A (en) * 1954-04-05 1959-04-14 California Packing Corp Spot scanner for comestibles

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US2229638A (en) * 1938-08-03 1941-01-28 Bethlehem Steel Corp Inspecting apparatus
US2395482A (en) * 1943-03-22 1946-02-26 Jr Samuel C Hurley Photoelectric inspection device
US2433685A (en) * 1943-11-03 1947-12-30 Tennessee Coal Iron And Rallro Apparatus for separating defective sheets as sheared from continuous strip
US2563213A (en) * 1949-06-01 1951-08-07 United States Steel Corp Control unit for pinhole detectors
US2570288A (en) * 1949-05-03 1951-10-09 Howard Paper Mills Inc Photoelectric inspection of sheet materials

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2229638A (en) * 1938-08-03 1941-01-28 Bethlehem Steel Corp Inspecting apparatus
US2395482A (en) * 1943-03-22 1946-02-26 Jr Samuel C Hurley Photoelectric inspection device
US2433685A (en) * 1943-11-03 1947-12-30 Tennessee Coal Iron And Rallro Apparatus for separating defective sheets as sheared from continuous strip
US2570288A (en) * 1949-05-03 1951-10-09 Howard Paper Mills Inc Photoelectric inspection of sheet materials
US2563213A (en) * 1949-06-01 1951-08-07 United States Steel Corp Control unit for pinhole detectors

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2933185A (en) * 1955-05-11 1960-04-19 United States Steel Corp Method and apparatus for classifying sheets according to length
US2917168A (en) * 1955-12-13 1959-12-15 Time Inc Mechanism for separating bound and unbound books
US2977114A (en) * 1956-08-06 1961-03-28 Pitney Bowes Inc Document feeding apparatus
US3035694A (en) * 1957-04-09 1962-05-22 Int Standard Electric Corp Article sorting control apparatus
US3017992A (en) * 1958-03-24 1962-01-23 Bartelt Engineering Co Inc Machine for classifying packages according to weight
US2990953A (en) * 1958-10-21 1961-07-04 Mosaic Tile Company Machine for detecting cracked ceramic tiles
US3239814A (en) * 1962-02-14 1966-03-08 Lionel Electronics Lab Inc Document testing and identification system
US3219184A (en) * 1962-04-26 1965-11-23 Dolph V Van Laanen Sorting apparatus
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GB708513A (en) 1954-05-05
FR1075253A (fr) 1954-10-14
BE516718A (pt)

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