US2446377A - Apparatus for inspecting moving transparent objects - Google Patents

Description

Aug. 3, 1948. H. H. MARSHALL 2,446,377

APPARATUS FOR INSPECTING MOVING TRANSPARENT OBJECTS Filed Aug. 29, 1944 4 Sheets-Sheet l INVENTOR ATTORN EYJ Aug. 3, 1948. H. H. MARSHALL 2,446,377

APPARATUS FOR INSPECTING MOVING TRANSPARENT OBJECTS Filed. Aug. 29, 1944 4 Sheets-Sheet 2 H T NVENTOR Aug. 3, 1948. H. H. MARSHALL 2,446,377

APPARATUS FOR INSPECTING MOVING TRANSPARENT OBJECTS 4 INVENTOR 5. g ORNE .5

Aug. 3, 1948. H. H. MARSHALL APPARATUS FOR INSPECTING MOVING TRANSPARENT OBJECTS Filed Aug. 29, 1944 4 Sheets-Sheet 4 INVENTOR Patented Aug. 3, 1948 APPARATUS FOR msPnc'rrNG MovrNo TRANSPARENT onmo'rs Henry Hall Marshall, Garden City, N. Y., assignor, by mcsne assignments to Pabst Brewing Company, Chicago, Ill., a corporation of Dela- Application August 29, 1944, Serial No. 551,759

' 8 Claims. (oi. 88-14) 1 This invention relates to inspection devices for light transmitting articles, and more particularly to visual inspection devices in' which light from a source is directed through containers or bottles and their contents which are transparent or translucent, whereby imperfections are indicated by shadow or interruption light;

In bottle handling operations,.it is customary to pass the bottles in linear succession on a conveyor or the like, for inspection by an observer, but after they pass the observer, a foreign particle in one of the bottles is diflicult to retain in view because the bottles pass out of focus and the light transmission and refraction by the contents vary to a degree making inspection uncertain.

It is the principal object of this invention to provide bottle. inspection apparatus in which the bottles pass from the conveyor in continuous contact along an arcuate path, whose center of curvature is at the observer's station, so that each bottle remains in focus during its entire course along the arcuate path and the light transmission and refraction therethrough remain constant, thus enabling accurate and certain inspection. 4 In their course along thearcuate inspection path the bottles mesh with apertures in an opaque screen which is accordingly advanced by and with the bottles and confines the light to the contents of the bottles, which are thus not only uniformly illuminated, but are also masked against glare. After leaving the arcuate inspection path, the bottles are returned to the conveyor in contacting relation and in synchronism with the oncoming bottles being fed by the conveyor, so that no delay in production is necessitated by the inspection.

Other objects and features of novelty will be apparent as the following description proceeds, with reference toothe accompanying drawings, in which:

Figure 1 is a horizontal section through the inspection device according to the preferred embodiment of the present invention, as taken along the line i--l of Figure 2;

Figure 2 is a vertical section taken along the line 2-2 of Figure 1;

Figure 3 is a detail elevation of a portion of the shield; I

Figure 4 is arvertical section taken along the line 4-4 of Figure 3; A

Figure 5 is a vertical section taken along the line 5-5 of Figure 1, showing the screen supporting reel;

Figure 6 is a section taken along the line 66 of Figure 5, and

of the transmitted of Figure 6.

According to the present invention, a shield of light resisting material is provided with apertures shaped to-receive the articles or containers to be inspected, the shield being flexible or articulated to form an endless belt enclosing the light source. The articles are fed to the inspection device by a conventional conveyor, and are deflected therefrom in contact along an arcuate path on an inspection table, the center of curvature of the inspection path being at the observer's position, so that the bottles are always the same distance from, the observer. As the articles are deflected, they enter the apertures on the screen belt, and carry the belt along with them.- Thus the articles remain in focus while inspected, glare being eliminated by the screen. A delivery guide directs the articles as they move off the table so that they pass ,out of the apertures and back onto the conveyor.

The inspection device shown in the drawings comprises a frame F which supports an inspection table T, to which the bottles 13 are fed by a conveyor 0. The screen S is provided with apertures A which receive the bottles B which move the screen with them as they pass along the table T in front of the lamp bank or other light source L. The screen is flexible or articulated to form an endless belt, which passes over or around vertical spools or reels R, and along a curved path whose center of curvature is at the observers position 0. A feed deflector M earns the bottles B off the conveyor C onto the table T and into the apertures A for travel in contact along the curved path whose center is at O, and a delivery guide D directs the bottles as they move ofi of; the table T and out of the apertures A and back onto the conveyor C.

As shown in Figures 3 and 4, the screen S is constructed of opaque material, preferably flexible, the form shown being asbestos fiber fabric impregnated with synthetic rubber. Vertical supporting and reinforcing rods H) are provided at equal intervals the screen being secured or clamped between the rods Ill and retaining strips l2 by screws l 4 passing therethrough.

A relatively wide band ii of the screen material is provided at the top, the lower portion of this band between each pair of adjacent rods I 0 being cut away as at IE to conform to the bottle neck and form the top of the aperture A. Above the cut away portion 46, and between each pair of adjacent rods Hi, the band I5 is provided with a reinforcing strip ll of the screen material which its machine stitched or otherwise secured in posi- The rods I 0 form the sides of the apertures A. and the bottoms of these apertures are formed by the top of a relatively narrow band (8 of the similar reinforcing strip a under each aperture.

Each rod "has secured to the bottom thereof a bracket 22, which provides a journal for a supporting roller 24. At the top of each rod ID a bracket 25 provides a Journal for a guide roller 2.

As shown in Figure 2, the lower or supporting rollers 24 ride on a track 30 having guide flanges on each side thereof, and the upper or guide rollers 26 pass between upper guide flanges Ii and 32. The track 3|! is mounted on the frame F below and in back of the inspection table T, which is supported from the frame F by suitable brackets or posts 33. The guides 3| and 32 are secured to a top plate 3|.

The guides 3i and 32 and the track 30 are curved about inspection center and track 30 extends between the front spools or reels RI and R2 in back of the inspection table T. It should be noted that this curved path is elongated, being ofgreater extent than the corresponding part of y the straight conveyor C, thereby permitting not only inspection at a constant distance from center 0 but allowing a substantial inspection time.

As shown in Figure 5, each reel R comprises a shaft 35 journaled in bearings I8 and having an upper flange 31 adapted to be engaged at its periphery by the guide rollers 28 at the upper ends of the rods II. The shaft 36 also carries a lower flange 38 which has a peripheral shoulder adapted to receive the supporting rollers 24 at the lower ends of the rods ill.

The reels R3 and R4 at the back of the inspection device have their bearings adjustably mounted so as to take up slack in the endless belt formed by the screen 8 so that as the rollers 24 and 26 engage their flanges, the screen material therebetween flattens or straightens out as shown in Figure 1.

The adjustable mounting for the bearings of the reels is shown in Figures 6 and 7. The hearing 36 is mounted in a cage ll which is slidable along a guide 42. A screw 43 extending longitudinally of the guide 42 threadedly engages the cage 40, and moves the cage along the guide, a coil spring 44 being provided to urge the cage outwardly.

As shown in Figure 1, straight guides otherwise similar to the track 30 and flanges SI and I! are provided to guide the remaining bights of the endless belt screen S. A guide 46 extends from dellvery reel R2 to the rear reel RI, 9. guide 41 extends between the real-reels R3 and R4, and a uide 48 extends from the rear reel R4 to the feed reel RI. These guides are adjustably mounted on the frame F by bolts entering slots 0 in the frame. g I

The light source L comprises a lamp bank or panel 50 extending vertically from the frame F. The panel Bil supports sockets ii for lamp bulbs 52 extending toward the bottles, the rear of the panel 50 having boxes 53 to enclose suitable wiring. Between the bulbs 52 and the bottles a ground glass panel 55 is provided to diffuse the light. As shown in Figure 2, the panel it rests in a groove 56 provided on the frame F, and is removably secured in position by a bolt and a wing nut 51 on the top plate 34.

As shown in Figure 1, the sides of the lamp bank L are enclosed by light shields extending forward from the panel 50, beyond the ground glass panel 55, and extending inwardly to the shafts 35 of the reels RI and R2. Thus the light is restricted to the extent of the inspection table T. In front of the inspection table I, as shown 4 in Figure 2, a splash shield n is provided, to cover the part of the conveyor 0 between the deflector M and the guide D. In front of the conveyor C an inspection window 8| of clear glass is provided.

Above the bottles on the inspection table T a guard plate II is suitably supported from the top plate 34, leaving an open space between the guard plate 8| and the window I for the withdrawal or rejected bottles.

In operation, the articles to be inspected, such as bottles, are fed into the inspection device by the conveyor C and engage the deflector M which cams them laterally oil. the conveyor C onto the inspection table T. This camming action causes the leading bottle to enter the aperture A of the screen 8, at the time when the screen is leaving the front feed reel RI and is moving onto the curved guide track 30. The width of the aperture A between adjacent rods I0 is less than the width of the bottle, so that the bottle cannot pass through the aperture, but enters and snugly engages it.

Although the leading bottle by this time has left the conveyor C, the oncoming bottles are pushed on by those following, and as the oncoming bottles enter the apertures A, the screen 8 is moved in the same direction by the oncoming bottles. The track 30 defines the path of the screen which in turn defines the path of the bottles in the apertures, along the inspection table T.

The lamp bank or light source L having been turned on, the light shines through the ground glass and through the bottles in the apertures. The opaque, closely fitting screen 8 obstructs the light outside the bottles, so that only the light passing through the apertures A may reach the inspector. Thus the bottles and their interiors are adequately illuminated for inspection purposes, while glare and excess light are eliminated. At the same time, the bottles are progressed through the machine so that the inspection operation may be rapidly accomplished at a constant distance from 0, and so that the inspector may view each bottle under the same conditions throughout its curved path, without distortion, variation in light intensity, or glare.

As the bottles reach the delivery front reel R2, they engage the delivery guide D which guides them back onto the conveyor C. The following bottles act to propel the leading bottles throughout their course onto and oil of the table T, while the screen 8 passes around the reel R2 to continue its circuit.

Although a preferred embodiment of the invention has been described herein, it is to be understood that the invention is not limited thereby, but is susceptible of changes in form and detail within the scope of the appended claims.

I claim:-

1. Inspection device for light transmitting articles, comprising in combination, a source of light, a conveyor for feeding the articles in linear succession in contact with each other in a path adjacent said' light source, a shield of light resisting material having apertures shaped to receive said articles, whereby light from said source is transmitted through said articles, and glare from said light source outside of said articles is obstructed, means for supporting said shield for lateral movement, means directing articles from said conveyor into the apertures in said shield, whereby said shield is moved by the articles being fed by said conveyor and entering said apertures,

and guiding means cooperating with said shield and conveyor for moving the articles along an arcuate path having a. center of curvature lying on the opposite side of the arcuate path from the light source.

2. Inspection device for light transmitting articles, comprising in combination, a source of light, a conveyor for feeding the articles in linear succession before said source of light, a shield of light resisting material having apertures shaped to receive said articles, means for mounting said shield vertically for movement in a horizontal path between said conveyor and said source of light, an inspection table between said conveyor and said shield, means for deflecting said articles oil? of said conveyor onto said table and into said apertures, and means for guiding said shield in an arcuate path between said conveyor and said light source.

3. Inspection device for light transmitting articles, comprising in combination, a source of light, a conveyor for feeding said articles in linear succession before said light source, a pair of reels journaled on vertical axes on respective sides of said light source, an endless belt of light intercepting material mounted on said reels and having apertures'shaped to receive said articles, an inspection table between said conveyor and said belt, means for deflecting said articles from said conveyor onto said table and into said apertures as the front bight of said belt leaves the feeding reel, and means for guiding said articles ofi said table and onto said conveyor when they leave said apertures as said front bight passes onto the receiving reel,

1. Inspection device for light transmitting articles, comprising in combination, a source of light, a conveyor for feeding the articles in rectilinear succession and contacting relation, a vertical shield of light intercepting material having apertures shaped to receive said articles and vertical supporting rods between said apertures, an inspection table in front of said light source and level with said conveyor, said shield comprising an endless-belt having an article receiving bight msing in front of said light source and along said inspection table, and a return bight passing in back of said light source, a deflector for camming each article in succession of! of said conveyor and onto said table into engagement with the rod of said shield ahead thereof, whereby the following articles still on said conveyor push the leaving article onto said table and into its aperture and propel said front bight across said table, and a delivery guide at the delivery end of said front bight for directing said articles leaving said table back onto said conveyor.

5. Inspection device for light transmitting articles. comprising in combination, a source of light, a conveyor for feeding the articles in rectilinear succession, a pair of reels having vertical shafts mounted at the respective sides of said source of light. an endless belt carried by said reels and having apertures shaped to receive said articles, vertical supporting rods secured to said belt between said apertures. an inspection table in front of said light source between said reels and level with said conveyor, a curved guide extending between said reels and located below said inspection table and in front 7 of said light source for deflecting the front bisht of said belt away from said conveyor and toward said light source, means for guiding the return bight of said belt from one reel to the other in back of said light source, a guide for directing each article in succession of! of said conveyor onto said table and into engagement with an aperture of said shield, and a delivery guide cooperating with said belt and conveyor for directing said articles off of said table and back onto said conveyor.

6. In a device for inspecting light transmitting articles from an inspection position, the combination of a light emitting panel of considerable area, a pair of reels having substantially parallel shafts mounted one on each side of said light panel. an endless belt of light intercepting material mounted on said reels and passing between said light panel and said inspection position, said belt having adjacent light transmitting apertures shaped to receive said articles, means cooperating with said reels to cause said belt to form an arcuate article receiving pass a lurality of adjacent apertures in length in front of said light panel and a return pass in back of said light panel, said arcuate pass having a center of curvature lying substantially at said observation position, and means directing articles to said arcuate pass and into said aperture. 1

7. In a device for inspecting light transmitting bottles from an inspection position, the combination of a light emitting panel of considerable area. a vertical shield of light intercepting material interposed between said light panel and said inspection position, said shield having apertures adapted to receive said bottles and vertical supporting rods secured to said shield between said apertures, supporting rollers Journaled at the bottoms of said supporting rods, and means cooperating with said shield and supporting rollers for guiding said shield along an arcuate path a plurality of adjacent article receiving apertures in length and having a center of curvature lying substantially at said inspection position.

8. In a device for inspecting light transmitting articles from an inspection position, the combination of a light emitting panel of considerable area, a shield of light intercepting material in-- terposed between said light panel and said inspection position, said shield comprising an endless belt and having adjacent light transmitting apertures formed therein within which said articles are adapted to be deceived, vertical supporting rods secured to said shield between said apertures, rollers journalled on said rods, means cooperating with said rollers for guiding said belt to form an arcuate article receiving portion in front of said light panel, a return portion in back of said light panel, said arouate belt portion including a plurality'oi' vadjacent article receiving apertures in its length and having a center of curvature lying substantially at said inspection position, and means directing light transmitting articles to one end of said arcuate belt portion and into said apertures.

HENRY HALL EiARSI-IAIL.

REFERENCES CITED The following references are of record in the file of this patent: 4

UNITED STATES PATENTS 2,368,350 Ellison Jan.- 80, 1945

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