Patent Application
20080072661
As shown in
As best seen in
The top side 40 of scoring head body 30 includes an axially centered bore 42. Bore 42 is surrounded by support reinforcement surfaces 44 and 46 appearing on top side 40 of scoring head body 30. One end 48 of shaft 50 is preferably force fitted within bore 42. The top end 52 of shaft 50 is coupled to ram 18 and secured thereto, for example, by threads 54 on shaft 50.
To produce a test specimen, a plastic bottle 14 is randomly selected from a plastic bottle production line. Referring again to
Referring to
In operation, bottle 14 is inserted into recess 82 with bottle ring 62 resting on the top surface 86 of support plate 78. It is noted that the height of columns 80 exceeds the height of a bottle to be modified by the present invention as measured from the bottom of the bottom wall 58 to the bottom of ring 62. Thus, when bottle 14 is positioned within support 12, a gap 89 will advantageously appear between bottle bottom 58 and support base 76. This results in bottle 14 being supported in the axial direction only on ring 62 and by top surface 86 of support plate 78 adjacent recess 82. It is noted that for smaller sized bottles having a ring 62 of a lesser diameter, narrower recesses 90 and 92 are provided in top plate 78. Thus, a smaller bottle will be supported in the appropriate narrower recess when producing test specimens from such smaller bottles.
Support 12 is positioned on table 77 so that bottle 14 is in axially alignment with scoring head 16, and thus when head 16 is advanced, blades 34 contact the top sealing surface 22 of bottle 14. Thereafter, blades 34 cut into the top sealing surface 22 to produce scores, or scorelines 94 and provide a test specimen bottle for evaluating the integrity of the seal of a closure; such as, for example, those test as described in U.S. Pat. No. 6,526,810 to Konieczki and U.S. Pat. No. 6,807,846 to Leonard, the disclosures of which are herein incorporated by reference.
In order to produce control bottles 14 which have consistent level of deformation, the downward movement of scoring head 16 is limited to a predetermined distance so that it is stopped at the same point when deforming each bottle. This results in producing a consistent depth for scores 94. Since the closures are tested with like deformed bottles, consistent and meaningful results can be obtained in seal integrity tests. Typically, a relatively shallow depth may be used. Those skilled in the art will appreciate that the actual depth selected will depend on the level of deformation which simulates a sealing surface quality which is at the low end of the quality tolerance of a bottle for a given type of bottle. Another way to produce bottles 14 with consistent deformations is to apply the same deforming force using press 20 whenever producing the scores 94 of bottle 14. An appropriate deforming force can include a force within a range from 30 to 70 pounds, for example, 50 pounds.
It is noted that the use of support 12, wherein the clearance between plate 78 and base 76 leaves bottle bottom 58 unsupported, ensures that the deforming forces of head 16 are absorbed along the rigid neck 60 area of bottle 14. Thus, the force of scoring head 16 does act upon the thinner wall sidewall 56 portion of bottle 14. This prevents fractures and leaks from forming in the thinner sidewall 56 during the scoring of top sealing surface 22 of rim 70. If a small leak or rupture occurs in sidewall 56 which is not visible to the naked eye, such leaks can cause the later testing of the closure to indicate a closure failure when, in fact, no failure of closure seal 66 has taken place, but rather a failure of bottle sidewall 56 has occurred.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.
