US3778802A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film inspection apparatus
Assignee: Harwald Co Inc
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Filing: 1972-03-20
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Granted: 1973-12-11
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Expires: 1992-03-20
Abstract
Abstract A film inspection apparatus is provided for detecting partial transverse breaks extending inwardly from an edge of the film, wherein the film is moved at extremely high speed over the periphery of a roller with an edge thereof overhanging the side of the roller to form a stiff arcuate portion which will withstand considerable outwardly directed radial force without substantial bending. A feeler element is biased into engagement with the concave side of said arcuate portion and moves radially outward when a generally transverse break in said edge is encountered. This radially outward movement of the feeler element deflects a cantilever beam piezoelectric element to produce a corresponding electrical signal. Film splices are also detected and counted while eliminating low amplitude or short duration pulses which may be due to dirt or other contaminants on the film. Splices longer than a predetermined amount are also detected and the film stopped, while facilities are provided for preventing the machine from being stopped in response to a series of closely spaced good splices which individually have a length less than said predetermined amount. Compensation is also provided for changes in film speed as the film is brought up to full speed so that relatively short good splices are not falsely interpreted as longer bad splices and the machine stopped. Elongated sprocket holes are detected by engagement of a feeler element with a straight line portion of the film so that vibration of the feeler element due to chord effect is eliminated and vibration is not transmitted to the edge break feeler elements. The response characteristic of the elongated sprocket hole feeler element is compensated by mechanical damping and by variation in the gain characteristic of the associated amplifier channel so that splices are not falsely interpreted as elongated sprocket holes. The splice detection channels, the elongated sprocket hole detection channel, and both edge break detector channels employ piezoelectric transducer elements, the signals from which are amplified without appreciable differentiation and transformed to low impedance levels prior to processing so that the desired movements of the respective feeler elements may be detected while the film is traveling at an extremely high rate of speed in the order of 1,600 feet per minute.
Inventors
- 👤 R Wallace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:22
CPC Classifications
G; G03; G03D; G03D15/00
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
144 words
A film inspection mechanism for detecting defects in the edges of the film, comprising in combination, an arcuate support over which the film may pass, means for advancing the film over the periphery of said support with an edge thereof extending outwardly beyond the side of said support, means for holding the film into engagement with said support with the overhanging portion of the film forming a stiff arcuate portion which will withstand considerable radially outwardly directed force on the concave side thereof without substantial deflection, a feeler element, means for biasing said feeler against the concave side of said overhanging portion with a radially outwardly directed force so that said feeler element moves radially outward when a defect in said edge portion is encountered, and means for developing a control signal in response to said radially outward movement of said second feeler element.
Claim 2
Dependent Claim
144 words
A film inspection mechanism for detecting defects in the edges of the film, comprising in combination, an arcuate support over which the film may pass, means for advancing the film over the periphery of said support with an edge thereof extending outwardly beyond the side of said support, means for holding the film into engagement with said support with the overhanging portion of the film forming a stiff arcuate portion which will withstand considerable radially outwardly directed force on the concave side thereof without substantial deflection, a feeler element, means for biasing said feeler against the concave side of said overhanging portion with a radially outwardly directed force so that said feeler element moves radially outward when a defect in said edge portion is encountered, and means for developing a control signal in response to said radially outward movement of said second feeler element.
Claim 3
Dependent Claim
26 words
The combination of claim 1, wherein said signal developing means includes a member which is mechanically stressed to produce an electrical signal by direct piezoelectric effect.
Claim 4
Dependent Claim
83 words
The combination of claim 2, wherein said biasing means comprises a spring tensioned arm in one end of which said feeler element is mounted, said member comprises a piezoelectric element in the form of a cantilever beam positioned so that the free end thereof is in proximity to said spring arm, and means interconnecting said spring arm and the free end of said cantilever beam so that said member is stressed in response to said radially outward movement of said first feeler element.
Claim 5
Dependent Claim
166 words
In a film inspection mechanism for detecting partial transverse breaks in the film extending inwardly from an edge thereof, the combination of, a base member, a detector assembly pivotally mounted on said base member and movable to a film test position, a pulley rotatably mounted on said assembly and adapted to guide the film in a curved test path when said assembly in said film test position, the outer edge of the film overhanging the side of said pulley and forming a stiff arcuate portion which resists a radially outwardly directed force, a spring arm mounted on said assembly and carrying a feeler element, said feeler element being positioned to engage the under side of said stiff arucate film portion when said assembly is in said film test position, and means responsive to radially outward movement of said feeler element when said assembly is in said test position and an edge break in the film is encountered by said feeler element for developing a control signal.
Claim 6
Dependent Claim
166 words
In a film inspection mechanism for detecting partial transverse breaks in the film extending inwardly from an edge thereof, the combination of, a base member, a detector assembly pivotally mounted on said base member and movable to a film test position, a pulley rotatably mounted on said assembly and adapted to guide the film in a curved test path when said assembly in said film test position, the outer edge of the film overhanging the side of said pulley and forming a stiff arcuate portion which resists a radially outwardly directed force, a spring arm mounted on said assembly and carrying a feeler element, said feeler element being positioned to engage the under side of said stiff arucate film portion when said assembly is in said film test position, and means responsive to radially outward movement of said feeler element when said assembly is in said test position and an edge break in the film is encountered by said feeler element for developing a control signal.
Claim 7
Dependent Claim
74 words
The combination of claim 4, which includes second spring arm fixedly mounted on said base member and carrying a second feeler element on the end thereof, said second feeler element engaging the upper side of the film at a point spaced laterally inwardly from said first named feeler element when said assembly is moved to said test position, thereby to hold the film against said pulley as it moves in said curved test path.
Claim 8
Dependent Claim
117 words
In a film inspection mechanism for detecting portions of the film such as splices which have a thickness which exceeds a predetermined value, the combination of, a pair of film-receiving rollers adapted to straddle a film, one of said rollers being fixedly mounted, means for moving the other roller toward and away from said one roller, means resiliently biasing said other roller toward said one roller, a piezoelectric element in the form of a cantilever beam, means responsive to movement of said other roller away from said first roller for stressing said element, and means for deriving a control signal in response to stressing of said piezoelectric element which indicates variations in the thickness of the film.
Claim 9
Dependent Claim
117 words
In a film inspection mechanism for detecting portions of the film such as splices which have a thickness which exceeds a predetermined value, the combination of, a pair of film-receiving rollers adapted to straddle a film, one of said rollers being fixedly mounted, means for moving the other roller toward and away from said one roller, means resiliently biasing said other roller toward said one roller, a piezoelectric element in the form of a cantilever beam, means responsive to movement of said other roller away from said first roller for stressing said element, and means for deriving a control signal in response to stressing of said piezoelectric element which indicates variations in the thickness of the film.
Claim 10
Dependent Claim
38 words
The combination of claim 6, wherein said other roller is rotatably mounted on a pivotally movable member, and resilient biasing means for urging said movable member in the direction to move said other roller toward said one roller.
Claim 11
Dependent Claim
28 words
The combination of claim 7 which includes stop means for limiting inward movement of said other roller by said biasing means to prevent overstressing of said piezoelectric element.
Claim 12
Dependent Claim
145 words
A film inspection arrangement comprising, in combination, a pair of film receiving rollers adapted to straddle the film, means fixedly supporting one roller, a pivotally mounted arm retractably supporting the other roller in relation to said one roller, means for developing an electrical signal in response to movement of said other roller away from said one roller when thickness discontinuities in the film pass between said rollers, means for moving the film between said rollers at a high rate of speed, detector means controlled by said electrical signal for developing an output signal when said thickness discontinuities exceed a predetermined length along the film, and means for automatically compensating said detector means for and in response to changes in the speed of said film so that thickness discontinuities less than said predetermined length do not cause said detector means to produce a false output signal.
Claim 13
Dependent Claim
145 words
A film inspection arrangement comprising, in combination, a pair of film receiving rollers adapted to straddle the film, means fixedly supporting one roller, a pivotally mounted arm retractably supporting the other roller in relation to said one roller, means for developing an electrical signal in response to movement of said other roller away from said one roller when thickness discontinuities in the film pass between said rollers, means for moving the film between said rollers at a high rate of speed, detector means controlled by said electrical signal for developing an output signal when said thickness discontinuities exceed a predetermined length along the film, and means for automatically compensating said detector means for and in response to changes in the speed of said film so that thickness discontinuities less than said predetermined length do not cause said detector means to produce a false output signal.
Claim 14
Dependent Claim
68 words
The combination of claim 9, wherein said detector means includes a storage capacitor, means for charging said capacitor in proportion to the duration of said electrical signal, means normally operative to develop said output signal when the charge on said capacitor reaches a predetermined amount, and means for varying the amount of charge necessary to develop said output signal in inverse relationship to the speed of said film.
Claim 15
Dependent Claim
41 words
The combination of claim 9, wherein said film moving means has a predetermined acceleration characteristic, said compensating means develops a second electrical signal simulating said acceleration characteristic, and said detector means is jointly responsive to said first and second electrical signals.
Claim 16
Dependent Claim
180 words
A film inspection arrangement comprising, in combination, a pair of film receiving rollers adapted to straddle the film, means fixedly supporting one roller, a pivotally mounted arm retractably supporting the other roller in relation to said one roller, means for developing an electrical signal in response to movement of said other roller away from said one roller when thickness discontinuities in the film pass between said rollers, means for moving the film between said rollers at a high rate of speed, detector means controlled by said electrical signal for developing an output signal when said thickness discontinuities exceed a predetermined length along the film, said detector means including a storage capacitor, means for charging said capacitor in proportion to the duration of said electrical signal, means operative to develop an output signal when the charge on said capacitor reaches a predetermined amount, and means for rapidly discharging said capacitor between electrical signals so that said output signal is not developed in resPonse to a series of closely spaced electrical signals which individually do not charge said capacitor said predetermined amount.
Claim 17
Dependent Claim
180 words
A film inspection arrangement comprising, in combination, a pair of film receiving rollers adapted to straddle the film, means fixedly supporting one roller, a pivotally mounted arm retractably supporting the other roller in relation to said one roller, means for developing an electrical signal in response to movement of said other roller away from said one roller when thickness discontinuities in the film pass between said rollers, means for moving the film between said rollers at a high rate of speed, detector means controlled by said electrical signal for developing an output signal when said thickness discontinuities exceed a predetermined length along the film, said detector means including a storage capacitor, means for charging said capacitor in proportion to the duration of said electrical signal, means operative to develop an output signal when the charge on said capacitor reaches a predetermined amount, and means for rapidly discharging said capacitor between electrical signals so that said output signal is not developed in resPonse to a series of closely spaced electrical signals which individually do not charge said capacitor said predetermined amount.
Claim 18
Dependent Claim
286 words
In a film inspection mechanism for detecting elongated sprocket holes in the film, the combination of, a base member, a detector assembly pivotally mounted on said base member and movable to a film test position, a first pulley rotatably mounted on said assembly, a second pulley rotatably mounted on said base member and offset from said first pulley when said assembly is in said test position so that the film extends in a straight line from its points of tangency with said first and second pulleys, means for advancing the film over said pulleys and along said straight line portion, a feeler element having a length greater than a normal sprocket hole in the film, means including a spring arm for resiliently biasing said feeler element into engagement with said straight line portion of the film and in alignment with sprocket holes in the film when said assembly is in said film test position, means for developing a control signal in response to movement of said feeler element into the film path when elongated holes are encountered, said signal developing means including a member which is mechanically stressed to produce an electrical signal by direct piezoelectric effect, said member comprising a piezoelectric element in the form of a cantilever beam positioned so that the free end thereof is in proximity to said spring arm and means interconnecting said spring arm and the free end of said cantilever beam so that said piezoelectric element is stressed in response to movement of said feeler element, and means defining a stop member fixedly positioned adjacent the free end of said piezoelectric element, and vibration damping means positioned between the free end of said piezoelectric element and said stop member.
Claim 19
Dependent Claim
286 words
In a film inspection mechanism for detecting elongated sprocket holes in the film, the combination of, a base member, a detector assembly pivotally mounted on said base member and movable to a film test position, a first pulley rotatably mounted on said assembly, a second pulley rotatably mounted on said base member and offset from said first pulley when said assembly is in said test position so that the film extends in a straight line from its points of tangency with said first and second pulleys, means for advancing the film over said pulleys and along said straight line portion, a feeler element having a length greater than a normal sprocket hole in the film, means including a spring arm for resiliently biasing said feeler element into engagement with said straight line portion of the film and in alignment with sprocket holes in the film when said assembly is in said film test position, means for developing a control signal in response to movement of said feeler element into the film path when elongated holes are encountered, said signal developing means including a member which is mechanically stressed to produce an electrical signal by direct piezoelectric effect, said member comprising a piezoelectric element in the form of a cantilever beam positioned so that the free end thereof is in proximity to said spring arm and means interconnecting said spring arm and the free end of said cantilever beam so that said piezoelectric element is stressed in response to movement of said feeler element, and means defining a stop member fixedly positioned adjacent the free end of said piezoelectric element, and vibration damping means positioned between the free end of said piezoelectric element and said stop member.
Claim 20
Dependent Claim
13 words
The combination set forth in claim 13, wherein said stop member is adjustable.
Claim 21
Dependent Claim
287 words
In a film inspection mechanism for detecting elongated sprocket holes in the film, the combination of, a base member, a detector assembly pivotally mounted on said base member and movable to a film test position, a first pulley rotatably mounted on said assembly, a second pulley rotatably mounted on said base member and offset from said first pulley when said assembly is in said test position so that the film extends in a straight line from its points of tangency with said first and second pulleys, means for advancing the film over said pulleys and along said straight line portion, a feeler element having a length greater than a normal sprocket hole in the film, means including a spring arm for resiliently biasing said feeler element into engagement with said straight line portion of the film and in alignment with sprocket holes in the film when said assembly is in said film test position, means for developing a control signal in response to movement of said feeler element into the film path when elongated holes are encountered, said signal developing means including a member which is mechanically stressed to produce an electrical signal by direct piezoelectric effect, said member comprising a piezoelectric element in the form of a cantilever beam positioned so that the free end thereof is in proximity to said spring arm and means interconnecting said spring arm and the free end of said cantilever beam so that said piezoelectric element is stressed in response to movement of said feeler element, and including means defining a stop member fixedly positioned adjacent the free end of said spring arm, and vibration damping means positioned between the free end of said spring arm and said stop member.
Claim 22
Dependent Claim
287 words
In a film inspection mechanism for detecting elongated sprocket holes in the film, the combination of, a base member, a detector assembly pivotally mounted on said base member and movable to a film test position, a first pulley rotatably mounted on said assembly, a second pulley rotatably mounted on said base member and offset from said first pulley when said assembly is in said test position so that the film extends in a straight line from its points of tangency with said first and second pulleys, means for advancing the film over said pulleys and along said straight line portion, a feeler element having a length greater than a normal sprocket hole in the film, means including a spring arm for resiliently biasing said feeler element into engagement with said straight line portion of the film and in alignment with sprocket holes in the film when said assembly is in said film test position, means for developing a control signal in response to movement of said feeler element into the film path when elongated holes are encountered, said signal developing means including a member which is mechanically stressed to produce an electrical signal by direct piezoelectric effect, said member comprising a piezoelectric element in the form of a cantilever beam positioned so that the free end thereof is in proximity to said spring arm and means interconnecting said spring arm and the free end of said cantilever beam so that said piezoelectric element is stressed in response to movement of said feeler element, and including means defining a stop member fixedly positioned adjacent the free end of said spring arm, and vibration damping means positioned between the free end of said spring arm and said stop member.
Claim 23
Dependent Claim
13 words
The combination set forth in claim 15, wherein said stop member is adjustable.
Claim 24
Dependent Claim
163 words
A film inspection arrangement comprising, in combination, a pair of film receiving rollers adapted to straddle the film, means fixedly supporting one roller, a pivotally mounted arm retractably supporting the other roller in relation to said one roller, means foR developing an electrical signal in response to movement of said other roller away from said one roller when thickness discontinuities in the film pass between said rollers, means for moving the film between said rollers at a high rate of speed, detector means controlled by said electrical signal for developing an output signal when said thickness discontinuities exceed a predetermined length along the film, and means for preventing said detector means from responding to electrical signals which do not exceed a predetermined minimum amplitude, said detector means including signal amplifying means, and signal integrating feedback means for said amplifying means, said feedback means causing electrical signals of less than a predetermined duration to be amplified by said amplifying means with substantially reduced gain.
Claim 25
Dependent Claim
163 words
A film inspection arrangement comprising, in combination, a pair of film receiving rollers adapted to straddle the film, means fixedly supporting one roller, a pivotally mounted arm retractably supporting the other roller in relation to said one roller, means foR developing an electrical signal in response to movement of said other roller away from said one roller when thickness discontinuities in the film pass between said rollers, means for moving the film between said rollers at a high rate of speed, detector means controlled by said electrical signal for developing an output signal when said thickness discontinuities exceed a predetermined length along the film, and means for preventing said detector means from responding to electrical signals which do not exceed a predetermined minimum amplitude, said detector means including signal amplifying means, and signal integrating feedback means for said amplifying means, said feedback means causing electrical signals of less than a predetermined duration to be amplified by said amplifying means with substantially reduced gain.
Claim 26
Dependent Claim
131 words
A film inspection arrangement comprising, in combination, a feeler element positioned on the end of a flexible spring arm member, means including said spring arm for resiliently biasing said feeler element into engagement with a moving film, means including a piezoelectric transducer element which is mechanically stressed in proportion to movement of said feeler element for developing an electrical signal by direct piezoelectric effect, means for amplifying said electrical signal without substantial differentiation of the signal components thereof, an integrating network connected to the output of said amplifying means for developing a modified output signal the amplitude of which is a function of the duration of said developed electrical signal, an amplitude selection means connected to said integrating network for selecting only those modified output signals which exceed a predetermined value.
Claim 27
Dependent Claim
131 words
A film inspection arrangement comprising, in combination, a feeler element positioned on the end of a flexible spring arm member, means including said spring arm for resiliently biasing said feeler element into engagement with a moving film, means including a piezoelectric transducer element which is mechanically stressed in proportion to movement of said feeler element for developing an electrical signal by direct piezoelectric effect, means for amplifying said electrical signal without substantial differentiation of the signal components thereof, an integrating network connected to the output of said amplifying means for developing a modified output signal the amplitude of which is a function of the duration of said developed electrical signal, an amplitude selection means connected to said integrating network for selecting only those modified output signals which exceed a predetermined value.
Claim 28
Dependent Claim
116 words
A film inspection arrangement comprising, in combination, a feeler element positioned on the end of a flexible spring arm member, means including said spring arm for resiliently biasing said feeler element into engagement with a moving film, means including a piezoelectric transducer element which is mechanically stressed in proportion to movement of said feeler element for developing an electrical signal by direct piezoelectric effect, and means for amplifying said electrical signal without substantial differentiation of the signal components thereof, said electrical signal developed in response to elongated sprocket holes in the film, and means for preventing said amplifying means for falsely responding to movements of said feeler element which are caused by splices in the film.
Claim 29
Dependent Claim
116 words
A film inspection arrangement comprising, in combination, a feeler element positioned on the end of a flexible spring arm member, means including said spring arm for resiliently biasing said feeler element into engagement with a moving film, means including a piezoelectric transducer element which is mechanically stressed in proportion to movement of said feeler element for developing an electrical signal by direct piezoelectric effect, and means for amplifying said electrical signal without substantial differentiation of the signal components thereof, said electrical signal developed in response to elongated sprocket holes in the film, and means for preventing said amplifying means for falsely responding to movements of said feeler element which are caused by splices in the film.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |