US3360983A - Vacuum support inspection head - Google Patents

Description

Jan. 2, 1968 v "r. E. SMITH r 3,360,983

VACUUM SUPPORT INSPECTION HEAD Filed Feb. 8, 1965 3 Sheets-Sheet 1 INVENTOR THOMAS E- SMITH Jan. 2, 1968 "r. E. SMITH 3,360,933 I VACUUM SUPPORT INSPECTION HEAD Filed Feb. 8,1965 a Sheets-Shee1; 2

INVENTOR THOMAS E. SMITH Jan. 2, 1968 T. E. SMITH 3,360,983

VACUUM SUPPORT INSPECTION HEAD Filed Feb. 8, 1965 s Sheets-Sheet s INVENTOR THOMAS -E- SMITH ATTORNEY United States Patent 3,360,983 VACUUM SUPPORT INSPECTION HEAD Thomas E. Smith, Lancaster County, Pa., assignor to Armstrong Cork Company, Lancaster, Pa., a corporation of Pennsylvania Filed Feb. 8, 1965, Ser. No. 431,055 7 Claims. (Cl. 73-453) ABSTRACT OF THE DISCLOSURE An inspection device for the testing of the linings for closures. The liner in a closure is tested by placing a plunger with a rigid ring adjacent the upper surface of the liner to form a pocket in which a vacuum may be pulled. A sleeve around the plunger presses on the outer edge of the closure. The direction of the pressure on the outer edge of the closure and the pressure on the center of the closure due to the existence of a vacuum result in a testing of the sealing quality of the liner.

The inspection apparatus of the prior art generally comprises valved, vacuum inspection heads for inspecting articles such as closure liners. Such construction results in relatively complicated inspection heads having internally moving parts including spring biased valve stems. Such apparatus is subject to wear and accumulation of foreign matter which may prevent proper opening and closing of the valve associated therewith. Malfunctions resulting from these causes require periodic maintenance as well as adjustment in order to keep said apparatus in operable condition.

With the development of plastic closure liners including sealing rings of polyethylene and polyvinyl plastisol, there arose a need for inspection apparatus which will accept closures having liners which will provide a commercially acceptable seal with regard to the package to which they will be applied, while rejecting those closures having liners which will not provide such a seal. The inspection apparatus of the prior art does not provide means to inspect closure liners having the aforementioned sealing rings.

Accordingly, it is an object of the present invention to provide inspection apparatus which is valveless in nature.

Another object of the present invention is to provide inspection apparatus having means to inspect sealing rings.

Other objects of the present invention will be apparent from the detailed description thereof with reference to the drawings wherein:

FIGURE 1 is a view in elevation of an inspection apparatus according to the present invention;

FIGURE 2 is a side view in elevation with portions broken away of the inspection apparatus shown in FIG- URE 1;

FIGURE 3 is a partial, sectional view of the inspection apparatus shown in FIGURE 2 taken along line 3-3 therein;

FIGURE 4 is a partial, sectional view of the inspection apparatus shown in FIGURE 2 taken along line 4-4 therein;

FIGURE 5 is a partial, sectional view of the inspection apparatus shown in FIGURE 2 taken along line 5 --5 therein;

FIGURE 6 is a partial, sectional view in elevation of an inspection head according to the present invention;

FIGURE 7 is an enlarged, partial, sectional view in elevation of the lower portion of the inspection head of FIGURE 6;

FIGURE 8 is a bottom view of the inspection head shown in FIGURE 7;

FIGURE 9 is a sectional view in elevation of an inspection head according to the present invention in an inspecting position with respect to a closure having a sealing ring;

FIGURE 10 is a partial View in elevation with portions broken away of an inspection head according to the present invention in an inspection position with respect to a. closure having a sealing ring with a defect therein;

FIGURE ll is a partial view in elevation of an inspection head according to the present invention in an inspection position with respect to a closure having a defective sealing ring;

FIGURE 12 is a plan view of a closure having a sealing ring with an out-of-round portion; and

FIGURE 13 is a partial, sectional view in elevation of an inspection head according to the present invention in an inspection position with respect to a closure having a defective sealing ring.

Referring now to FIGURES 1 and 2, there is shown inspection apparatus having a base 20 and a vertical support member 21 extending upwardly therefrom. Vertical support member 21 has an intermediate guide member 22 extending outwardly from vertical support member 21. Intermediate guide member 22 has a vertical bore 23 extending partially therethrough from the upper surface of said intermediate guide member to a point where said bore 23 communicates with a counterbore 24 which extends upwardly from the lower surface of said intermediate guide member 22.

A chuck 25 is reciprocatingly received by bore 23. Chuck 25 has an upper, closure-receiving cavity 26. Chuck 25 has a lower, bifurcated end 27 which receives cam roller 28. Cam roller 28 is mounted for rotation about pin 29 which is supported by bifurcated end 27 of chuck 25. Chuck 25 is provided with a flanged portion 30 which is located near bifurcated end 27. A spring 31 surrounds chuck 25 in counterbore 24 and extends downwardly therefrom to flange 30. Spring 31 acts on flange 30 to bias chuck 25 in a downward direction.

Block 32 extends upwardly from base 20. Cam 33 is secured to shaft 34 which is supported for rotation in suitable bearings in block 32. The periphery of cam 33 underlies and is substantially co-planar with cam roller 28. Spring 31 biases chuck 25 and cam roller 28 into contact with the periphery of cam 33. A conventional, variable speed motor, clutch, and coupling mechanism 35 may be provided to rotate cam 33. Rotation of cam 33 will cause chuck 25 to reciprocate in a vertical direction. As is seen in FIGURE 3, bore 23 and chuck 25 are rectangular in cross section to prevent chuck 25 from twisting in bore 23 and resultant misalignment of cam roller 28 and cam 33.

A lateral guide member 36 extends outwardly from vertical support member 21 in overlying relationship to intermediate guide member 22. Upper guide section 37 extends upwardly from lateral guide member 36. Bore 38 extends downwardly through upper guide section 37 into lateral guide member 36. Bore 38 has an upper threaded portion 39. Bore 40 has a smaller diameter than bore 38 and extends upwardly from the lower surface of lateral guide member 36 into communication with bore 38. Bores 38 and 40 are aligned with bore 23. A vertical slot 41 communicates bore 38 with the exterior of upper guide section 37.

An inspection head assembly 42 is reciprocatingly received by bore 38 and bore 40. Inspection head assembly 42 has an upper body 43, a neck 44 depending from said upper body 43, an annular collar 45 adjustably secured to and extending outwardly from said neck 44 at an intermediate location thereon, and a lower body portion 46 depending from said neck 44. Annular collar 45 is secured to neck 44 by conventional set screw means.

Upper body 43 is located in bore 38 with the upper portion of neck 44 extending downwardly through bore 40. The annular flange formed by the juncture of bores 38 and 40 cooperates with the flange formed by the juncture of upper body 43 and neck 44 to serve as a lower limit with regard to movement of inspection head assembly 42. As shown in FIGURE 4, upper body 43 and bore 38 may be rectangular in cross-section to prevent misalignment between these elements. A spring 47 is located in bore 38 above upper body 43. A threaded plug is received in upper threaded portion 39. Plug 48 may be adjusted within bore 38 to compress spring 47 and bias upper body 43 and inspection head assembly 42 into its lowermost position against the annular flange formed by the juncture of bores 38 and 40.

An annular sleeve 49 surrounds lower body 46. Sleeve 49 has a bore 50 which surrounds the lower portion of neck 44 as shown in FIGURES 2 and 6. Sleeve 49 also has a bore 51 which surrounds lower body 46. The flange formed by the juncture between bores 50 and 51 cooperates with the shoulder formed by the juncture of neck 44 and lower body 46 to limit downward movement of sleeve 49 with respect to lower body 46. A spring 52 surrounds neck 44 between collar 45 and the upper portion of sleeve 49 to bias sleeve 49 into its lowermost position with respect to lower body 46. It should be noted that when sleeve 49 is in its lowermost position, the lower surface thereof is below the lowest portion of lower body 46.

As shown in FIGURES 6 and 7, inspection head assembly 42 is provided with a central bore 53 which communicates with orifice 54 located in the lower portion of lower body 46. Orifice 54 communicates bore 53 with the exterior of the inspection head. The upper portion of bore 53 communicates with the lateral passage 55 which in turn communicates with a nipple 56 secured to upper body 43. It should be noted that nipple 56 is received in slot 41 and is free to move vertically therein. Suitable conduit means 57 of a flexible nature connect nipple 56 with a conventional low pressure or vacuum source 58.

The lower portion of lower body 46 forms the closure or article-receiving portion. A rigid, annular inspection or gauge ring 59 is located on the lower face of lower body 46 in surrounding relationship to orifice 54. Ring 59 is of a predetermined size and shape corresponding to a surface which is to be sealed by the sealing liner to be tested and inspected by the inspection head. A plurality of circumferentially spaced, arcuate feeler segments 60 extend downwardly from the lower body 46 to a point below the lowermost extent of ring 59. Segments 60 are located between ring 59 and orifice 54 in surrounding relationship to said orifice 54. A similar set of circumferentially spaced, arcuate feeler segments 61 extend from the lower portion of lower body 46 to a point below ring 59 but above the lowermost extent of segments 60. Segments 61 are positioned on the outer side of ring 59. The particular configuration of the inspection gauge ring 59 and feeler segments 60 and 61 shown in FIGURES 6 and 7 is that which may be used to inspect a closure with a plastisol liner of a specific geometric configuration.

The operation of the device will now be described. A closure 62 having a sealing ring 63 to be inspected is placed in chuck cavity 26. Cam 33 is rotated to cause chuck 25 and closure 62 to move upwardly whereupon the periphery of closure 62 will contact the lower periphery of sleeve 49. Continued upward movement of chuck 25, and closure 62 will cause sleeve 49 to be moved upwardly with respect to lower body 46 against the bias of spring 52 until sealing ring 63 contacts inspection ring 59. Continued upward movement of closure 62 with respect to inspection head 42 will cause rigid ring 59 to seat itself in resilient sealing ring 63 as shown in FIG- URE 9, for example. Spring 47 biases inspection head 42 downwardly to maintain contact between ring 59 and sealing ring 63.

It should be noted that there are no valves between the vacuum source 58 and orifice 54, thereby providing a valveless, constant vacuum arrangement. If the orifice 54 is quite small on the order of .014 in diameter, for example, air flow through said orifice when no closure is in inspection position will be quite small. This small air flow will allow the use of a small vacuum source 58. In any event, once ring 59 is seated in sealing ring 63, the air in the space between lower body 46 and the inside of closure 62 interiorly of sealing ring 63 will be evacuated by the vacuum source through orifice 54, bore 53, passage 55, nipple 56, and conduit means 57.

If there is an adequate seal between inspection ring 59 and sealing ring 63, there will be no appreciable air flow through orifice 54 once the interior of the closure 62 has been evacuated. The difference in pressure between the inner portion of the closure which has been evacuated and the outer portion thereof acts on the closure 62 in a manner which provides a retention force tending to hold the closure on the inspection head assembly 42. This force will be at a maximum when there is a perfect seal between the sealing ring 63 and the inspection ring 59 and consequently, no air flow through orifice 54. The spring 52 is chosen and the effect thereof adjusted by means of adjustable collar 45 so that the force acting on sleeve 49 tending to strip closure 62 from the inspection head will be less than that maximum force tending to retain an acceptable closure on the inspection head. Thus a closure having an acceptable sealing ring will remam in contact with the inspection head when chuck 25 is removed therefrom. This closure may then be manually or otherwise stripped from the inspection head.

If sealing ring 63 has a defect such as a low spot 64, for example as shown in FIGURE 10, and said low spot 64 is of such an extent as to prevent the sealing between inspection ring 59 and sealing ring 63, there will be a flow of air through said low spot 64 into the interior of the closure 62. In such a case, the pressure differential between the inside of the closure 62 adjacent the inspection head and the outside of said closure 62 will be less than the maximum value noted above where there is no leakage. The reduced pressure differential will result in a reduced retention force acting on closure 62 to retain it in contact with the inspection head. Thus, where the retention force is less than the stripping force exerted by spring 52 through sleeve 49 on closure 62, the closure will not be retained on the inspection head should the chuck 25 be.

moved downwardly to the position shown in FIGURE 2. By adjusting the collar 45 on neck 44 the effect of the spring on sleeve 49 and the resultant stripping force may be varied. It can be determined by experimentation the proper amount of stripping force that is required to reject closures having sealing liners which have defects serious enough to preclude a satisfactory and/or commercially acceptable seal when they are applied to articles which are to be sealed.

From a practical standpoint, the sensitivity of the device can be controlled by controlling the size of the orifice; and the proper orifice size may be determined according to the results of experimentation which will show which size orifice will reject closures having sealing rings which will not seal properly when applied to containers which are to be sealed. It is to be understood that the use of a relatively small orifice on the order of .010" to .020" in diameter, for example, is desirable to keep the air flow through the orifice at a minimum and to obtain the desired sensitivity of operation. Further, the size of the passages and conduit means between the orifice and the vacuum or low pressure source should be sufficiently greater than the orifice size such that the pressure drop on the downstream side of the orifice will be negligible. This arrangement will provide a substantially constant vacuum or low pressure reference at the downstream side of the orifice. The use of a small size orifice and relatively larger passage and conduit means as noted above will allow a relatively small vacuum or low pressure source to be used, and no valve or other flow control means will be required between the orifice and the low pressure or vacuum source. The omission of such a valve or flow control means between the orifice and vacuum or low pressure source provides greater accuracy of inspection as well as omitting the operating and maintenance problems associated with such a valve or flow control means. However, it should be noted that this arrangement does not preclude the use of an orifice which is adjustable in nature. Thus, this apparatus can accurately determine the acceptability of sealing rings in closures.

In the prior discussion, it was noted that the inspection ring 59 will not seat properly if the sealing ring 63 contains a defect such as a low spot 64, which may be sufficient to prevent adequate sealing action. Similarly, the ring 59 will detect other flaws and prevent scaling in the same manner. In fact, any defect in a given sealing ring which will allow a predetermined unacceptable air flow therethrough when said ring is placed adjacent the inspection ring 59 will cause said sealing ring and its associated closure to be stripped from the inspection head and rejected. In the case of out-of-round sealing rings such as shown in FIGURE 12, for example, a feeler segment 61 will contact the out-ofround portion 65 of the sealing ring and prevent the inspection ring 59 from sealing therewith. In this case, air will be allowed to flow through the spaces between segments 61, between inspection ring 59 and sealing ring 63, and through the spaces between segments 60 to orifice 54. As in the examples noted above, the pressure differential for sealing rings having a degree of out-of-roundness which will produce an unacceptable seal when applied to a container will not be sufficient to provide a force which will retain the closure in contact with the inspection head, and said closure will be stripped from said head and rejected. It is apparent that outer segments 61 will also prevent a proper seal being made between inspection ring 59 and sealing rings which have greater than-max mum acceptable diameter such as that shown in FIGURE 11. Conversely, if a particular sealing ring has a diameter which is below the minimum acceptable diameter, the segments 60 will prevent the sealing ring 63 from being seated on inspection ring 59. In each case, the closure having the defective sealing ring will be stripped from the inspection head by sleeve 49 and rejected.

In the example shown in FIGURE 13, where the sealing ring 66 does not have sufficient height, feeler segments 60 will prevent inspection ring 59 from making a proper seal with sealing ring 66 thereby allowing air to pass through the spaces between segments 61 and segments 60 to the interior of the closure. As in the cases noted above, such air flow will provide a relatively low pressure differential between the inside and the outside of the closure which will result in a retention force which is insufficient to retain the closure in contact with the inspecton head. Such a defective closure will be stripped from the head and remain in the chuck cavity 26. The same action would occur if the closure being tested was devoid of sealing material.

Thus, it is apparent that the device of the present invention provides for accurate inspection of sealing rings in articles. Further, the device of the present invention provides a relatively uncomplex apparatus for the inspection of sealing rings. The apparatus according to the present invention is economical to manufacture and maintain in relation to the prior art devices. It should be noted that the shape and size of inspection ring and feeler means depend upon the size and shape of the sealing ring, closure, or article to be inspected. The device of the present invention may be used to inspect defects in many types of sealing means in articles and is not limited to inspecting sealing rings in closures or a particular type of sealing ring in a particular type of closure. Similarly, the inspection apparatus of the present invention may be used to inspect sealing means of many different types of materials and is not limited to the inspection of those materials described herein. It is to be understood that all elements including the inspection head may be sectionalized and secured together with conventional fastening means for assembly purposes as would be obvious to a skilled mechanic or machinist. It is to be understood that the shapes, s'zes, andrelative location, composition, and materials of construction of the elements of the present invention may be varied, and that the present invention is not limited to the specific embodiment shown and described herein. For example, the number of arcuate segments and positioning thereof as well as the spaces therebetween may be varied and staggered without departing from the scope of the present invention.

Various modifications of the present invention will occur to those skilled in the art without departing from the spirit and scope thereof as defined in the claims.

I claim:

1. An inspection head comprising a body including an article-receiving portion, orifice means on said article-receiving portion, passage means in said body connecting said orifice means with the exterior of said body at a point spaced from said article-receiving portion, rigid, annular, gauge means on said article-receiving portion surrounding said orifice means, sleeve means surrounding said body adjacent said article-receiving portion and adjustable bias means to bias said sleeve means against the peripheral edge portion of the article being tested and to provide a force tending to dislodge said article from its test position, said passage mean connected to the chamber formed by the article, the gauge means and the article-receiving portion to provide a force opposing the first-mentioned force whereby leakage past the gauge and article causes a force differential and rejection of the article.

2. An inspection head according to claim 1 further comprising inner feeler means located on said article-receiving portion between said orifice means and said rigid, annular gauge means, said feeler means extending outwardly from said article-receiving portion.

3. An inspection head according to claim 2 further comprising outer feeler means located on said article-receiving portion outwardly of said annular gauge means.

4. An inspection head according to claim 1 further comprising feeler means located on said article-receiving portion outwardly of said annular gauge means.

5. A valveless inspection head comprising a body including an article-receiving portion, orifice means on said article-receiving portion, valveless passage means in said body connecting said orifice means with the exterior of said body at a point spaced from said article-receiving portion, rigid, annular, gauge means on said article-receiving portion surrounding said orifice means, sleeve means surrounding said body adjacent said article-receiving portion, and adjustable bias means to bias said sleeve means against the peripheral edge portion of the article being tested and to provide a force tending to dislodge said an ticle from its test position, said passage means connected to the chamber formed by the article, the gauge means and the article-receiving portion to provide a force opposing the first-mentioned force whereby lealcage past the gauge and article causes a force differential and rejection of the article.

6. A valveless inspection head according to claim 5 further comprising feeler means located on said article-receiving portion.

7. An inspection head comprising a body including an article-receiving portion, orifice means on said articlereceiving portion, passage means in said body connecting said orifice means with the exterior of said body at a point spaced from said article-receiving portion, annular gauge means on said article-receiving portion surrounding 7 8 said orifice means, sleeve means surrounding said body ad- References Cited j acent said article-receiving portion, and adjustable bias UNITED STATES PATENTS means to 'bias said sleeve means against the peripheral edge portion of the article being tested and to provide gurkett a force tending to dislodge said article from its test posi- 5 2901906 9/1959 BS2 1 73 37 mom, said passage means connected to the chamber formed 3:O15:388 1/1962 Wilckens 73 45.3

by the article, the gauge means and the article-receiving portion to provide a force opposing the first-mentioned LOUIS PRINCE Primary Examiner force whereby leakage past the gauge and article causes a force differential and rejection of the article. 10 NOLTON Assistant Emmmer'

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