US 4,047,613 AGranted

Means and method for inspecting in-process aerosol container closures

AssigneeCrown Cork & Seal Company, Inc.

InventorGeorge W. Wright

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Abstract

An optical and electromagnetic system for checking aerosol container closures for split curls, and for the presence of a continuous bead of sealing compound. The compound is applied to a depression about the periphery of inverted closures, and closures conveyed in single file fashion to an inspection station. A light source disposed in a rotating head above the inspection station scans the periphery of each closure, while a sensor rotating with the source responds to interruptions or voids in the compound. An electromagnetic transducer is rotatably mounted beneath the station and simultaneously scans the curl at the bottom of the inverted closure, producing a defect signal if a split curl is detected. A signal processing system prevents the system from reacting to spurious signals caused by the transit of closures past the inspection station. A counting stage delays the application of a reject signal until the defective closure has passed to an ejection station, at which time an ejection mechanism is triggered and the closure removed from the conveying system.

Claims14

Dependent claims

Apparatus for inspecting top closures for aerosol containers, said closures having an outer, peripheral depressed flange for receiving a quantity of sealing compound and an inner, curled flange, comprising:

conveying means for guiding closures in single file succession along a predetermined path, said path including an inspection position;
a first rotary inspection head axially aligned with a closure in an inspection position;
drive means for said inspection head;
a light source disposed in said head for directing a beam of light toward the periphery of a closure in said inspection position;
a first sensing means responsive to light from said source and disposed in said head to receive light from said source reflected by the periphery of the closure for outputting a first defect signal;
a second rotary inspection head axially aligned with a closure in an inspection position;
drive means for said second head;
electromagnetic transducer means disposed in said second head for applying an electromagnetic field to a portion of the inner, radial flange of a closure and for sensing a manifestation of field continuity in said flange;
second sensing means associated with said electromagnetic transducing means and responsive to sensed fluctuations in field continuity for outputting a second defect signal;
gating means responsive to the periodic advancement of closures for producing a discharge enabling signal so that spurious defect signals are not produced by the sucession of one closure by the next;
delay means for receiving said defect signals, said delay means being coupled to said gating means and to said sensing means for producing a reject signal a controllable time subsequent to the production of a defect signal;
and
ejection means coupled to said delay means and responsive to said reject signal to eject a closure bearing a previously-sensed defect from said conveying means.

10 more elements

A method of inspecting top closures for aerosol containers having an outer, peripheral depressed flange for receiving a quantity of sealing compound and an inner, curled flange, comprising the steps of:

sequentially conveying ones of said closures along a path including an inspection station;
disposing a source of light above said inspection station;
rotating said source of light substantially concentrically with a closure at said station;
sensing light reflected from the depressed flange of said closure;
producing a signal representative of a discontinuity in reflectance of said flange area, said discontinuity representing a gap in sealing compound thereon;
producing an eject signal in response to said defect signal;
delaying the production of said eject signal until a sensed defective closure has traversed said path to an ejection station;
and
ejecting the sensed defective closure.

6 more elements

Dependencies are inferred from the claim text.