JP2010089840A - Closure plug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a closure plug by which clamp and loop forming problems of a sealing gasket are overcome. <P>SOLUTION: The external thread closure plug 60 for closing up an internal thread opening 23 firmly when in transportation is formed as a cup having a bottom wall and a threaded cylindrical sidewall 23 which terminates at a circumferentially enlarged rim 4. There is a gasket seat 64 demarcated by an annular gasket holding lip 61 lying in a plane parallel to the undersurface of a plug rim, the sidewall of the plug and the undersurface of the plug rim below the rim of the plug. When in use, the plug is screwed into the opening of a container wall or removed from its opening and has an internally threaded portion and an unthreaded portion 30, the sealing gasket 12 is compressed between the unthreaded opening and the plug gasket seat 64 and lies in a proximate condition with an internal thread. The gasket seat is acted to inhibit that the sealing gasket 12 and the internally threaded portion opened are engaged mutually. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improved container closure plug, and more particularly to a threaded plug having a unique gasket retention mechanism.

  In the shipping container industry, the manufacture of drums, pails, etc. having one or more spouts and / or filling ports is most common. Such an opening has a helical internal thread that merges with the unthreaded gasket sealing region. An external threaded closure plug holding an annular sealing gasket is threaded into the opening. When the plug is tightened, the plug gasket is securely tightened against the unthreaded gasket sealing area to allow effective sealing of the container. Millions of drums and other containers are sealed in this manner, but problems can arise and the present invention addresses that problem. This problem is not only related to sealing, but also to unscrewing the plug from the container opening. There is an important relationship on the one hand to the plug and its gasket and on the other hand to merge the thread of the container opening into the open gasket pedestal region. This relationship is such that when the torque required to actually seal the plug into the container opening is applied, the plug gasket is wedged against the run-out of the opening internal thread. . When the plug is subsequently loosened, it is all that commonly occurs that the plug gasket is gripped without loosening due to this wedge action of the gasket against the open thread. As the loosening action continues, a tenuous state follows. Most notably, as the plug moves out of the opening, the gasket may remain in the threads inside the opening, causing the gasket to be pulled away from the gasket seat position of the plug. Since the gasket can be used between the threads to be fitted, it is very difficult to continue the rotation of the plug. Furthermore, the gasket itself is severely damaged by such shredding which further reduces the utility of closure.

  Another negative aspect of the gasket being held tight is the tendency for the gasket to loop out of the gasket pedestal while torque is applied to the plug. This problem occurs when plug gasket movement is hindered around the unthreaded gasket pedestal of the opening, which causes the gasket to pleat (set in one place) and form a loop protruding from the edge of the opening. . One situation in which such a problem occurs is when the plug gasket is reinserted into the threaded portion of the opening when the plug is moving into the opening. The resulting “loop formation” condition most certainly creates a leakage path and is very likely to cause serious damage to the gasket. Of course, the commonality of these “gripping” and “looping” problems is that the plug gasket is held over the thread engagement by holding the plug gasket in place on the plug gasket pedestal to which the plug gasket belongs. This is the ability to prevent dragging.

  It has been found in the prior art that it is generally desirable to provide some positive mechanical holding means that holds the plug gasket in place. For example, U.S. Pat. No. 5,211,304 to Stolzman discloses a plug configuration in which a gasket is securely held on the underside of the rim of the plug with a mechanical interlock device. However, this device places the gasket radially outward of the plug thread and has nothing to do with solving any gasket "gripping" or "looping" problem. Another prior art example can be found in US Pat. No. 2,906,429 to Marchyn, which captures the “loop formation” problem but fails to provide a completely satisfactory solution. In this patent, the plug has special threads where the threads form a boundary with the gasket pedestal. Specifically, the plug has a continuous decreasing thread around the lower edge of the gasket pedestal and acts as a partial barrier above the normal plug thread. However, this modified thread configuration is insufficient to provide sufficient protection against the “gripping” phenomenon, as will be seen clearly below.

US Pat. No. 5,211,304 US Pat. No. 2,906,429

[Object of the present invention]
It is an object of the present invention to provide a closure plug that overcomes the gripping and looping problems of sealing gaskets. Another object of an embodiment of the present invention is to provide a closure plug that fits in a range of container openings.

[Brief overview of the invention]
In accordance with the present invention, the closure plug is formed with a cylindrical side wall having a helical thread and terminating in a circumferentially enlarged rim and having an annular gasket pedestal directly below the plug rim. A continuous circumferential gasket retaining lip extending outward in the direction is disposed between the plug gasket pedestal and the sidewall thread.

  According to one embodiment of the present invention, the gasket retaining lip is substantially collinear in the axial direction with the thread valley diameter.

  According to another embodiment of the present invention, the gasket retaining lip has a shorter radial extension than the outer radial extension of the top of the sidewall thread, and the inner diameter of the root of the gasket retaining lip is It is smaller than the diameter of the thread valley.

  According to this alternative embodiment variant, the gasket pedestal extends in a flared shape radially outward and upward so as to abut the rim.

  According to another variant of this alternative embodiment, the gasket pedestal is provided with a peripheral groove at the base of the gasket holding lip.

  According to a further aspect of the invention, the sealing gasket is disposed on the gasket pedestal. The sealing gasket is elastic and can be stretched over the plug to hold the gasket pedestal firmly. In the case of a closure plug according to the above variant of this alternative embodiment, the sealing gasket takes the form of a flared gasket pedestal.

  Also in accordance with the present invention, the closure plug is combined with a container wall opening having an internal threaded portion and an unthreaded portion, and the sealing gasket is compressed between the unthreaded opening portion and the plug gasket base, A continuous circumferential gasket retaining lip that is in close proximity to the threads and extends radially outward is disposed between the plug gasket and the sidewall threads, and includes a sealing gasket and an internal threaded opening. By preventing the parts from interengaging with each other, the plug and the sealing gasket as a non-disturbing device can be loosened without interruption.

  The closure plug according to the present invention provides a long sought solution to the above-mentioned "gripping" and "looping" problems in a simple and simple manner.

  By way of example, the closure plug is formed with a threaded cylindrical side wall and a disk-like bottom wall. The side wall terminates in a circumferentially enlarged rim and has an annular gasket pedestal directly below the rim. A gasket retaining lip is disposed between the plug gasket pedestal and the sidewall thread. The elastic sealing gasket is stretched on the plug gasket pedestal and occupies a vertical space between the plug rim and the retaining lip. The plug described above is screwed into a container wall opening having internal threads and an inward gasket sealing area. The important prior art relationship between the plug gasket and the container opening thread is no longer trivial. As the plug is pulled back out of the threaded container opening, the gasket is securely held in place on the plug gasket pedestal by the gasket retaining lip. The resulting complete separation of the plug gasket from the container opening provides a significant improvement over the prior art.

  Accordingly, a key feature of the present invention is to provide an improved threaded closure plug for industrial size containers.

  Another feature is to provide a threaded closure plug having a new and improved gasket pedestal structure.

  A more detailed feature is to provide a plug gasket pedestal having a structure that securely holds the plug gasket during screwing and loosening.

  Other and more detailed features will be in part apparent and in part pointed out as the description of the invention proceeds in conjunction with the accompanying drawings.

These and other features of the invention are set forth in the appended claims and further illustrated in the drawings.

FIG. 3 is a partial elevational partial cross-sectional view of a closure plug according to an embodiment of the present invention. 2 is a top view of a combination of container closures incorporating the closure plug of FIG. FIG. 2 is a partial cross-sectional partial elevation view of the plug of FIG. 1 screwed into the container opening. Fig. 4 is a view similar to Fig. 3, but with the plug in a partially loosened position. It is a figure similar to FIG. 4 which shows a prior art. 4 is a partial cross-sectional detail of a closure plug according to a second embodiment of the present invention. It is a figure similar to FIG. 6, and is a figure which has a sealing gasket. FIG. 4 is a partial cross-sectional partial elevation view of a closure plug according to a third embodiment of the present invention screwed into a container opening. FIG. 9 is a view similar to FIG. 8, but with the plug in a partially loosened position. 4 is a partial cross-sectional detail of a third embodiment of a closure plug according to the present invention.

Detailed Description of the Invention
A closure plug according to a first embodiment of the present invention is shown in FIGS. 1 to 4, generally indicated by reference numeral 1, which is molded from a synthetic plastic resin and terminates in a circumferentially enlarged rim 4. The disc-shaped bottom wall 2 is surrounded by a cylindrical side wall 3. The interior of the plug 1 has a series of wrench engaging lugs 5 that provide screwing / relaxing torque to the plug. The plug side wall 3 has a pilot portion 6 extending from the bottom wall 2, a helical external thread 7, and a gasket pedestal 8 located directly below the plug rim 4. Here, it is important to note that the gasket pedestal 8 lies on a surface that is collinear with the diameter of the plug thread valley. This relationship is beneficial in that it ensures a sufficient gasket volume between the plug and the mating container opening surface to block any leakage path. The plug side wall 3 is formed with a circumferential gasket retaining lip 9 at the upper end of the thread 7, and this circumferential gasket retaining lip 9 is radially outwardly collinear with the thread summit. It is extended. As clearly shown in FIG. 1, the plug screw thread terminates at a point 10 in the lip 9, and is located on a plane parallel to the lower surface 4 a of the plug rim 4 and directly above the screw thread end point 10. The upward continuous annular surface 11 is left. An elastic annular sealing gasket 12 having a substantially square cross-sectional shape is stretched over the plug so as to hold the gasket base 8 firmly. The gasket thus positioned is tightly pressed between the lower surface 4a of the plug rim 4 and the upper surface 11 of the retaining lip 9, and the possibility of the gasket 12 being detached from the gasket base 8 is very low.

  As clearly shown in FIG. 3, the container wall opening into which the plug 1 is screwed consists of a container wall 20 into which a bushing, indicated generally at 21, is inserted in a conventional manner. The bushing 21 has a polygonal bottom 22 extending in the circumferential direction and a cylindrical wall 23 extending from the bottom and terminating in a bead 24 curled radially outward. The container wall 20 has a generally cylindrical upstanding neck 26 with a mating embossment 25 on the polygonal bottom 22 and extending into a bushing curl 24. The bushing gasket 27 is compressed between the bushing 21 and the peripheral surface of the container wall 20. A spiral internal thread 28 is formed in the bushing wall 23 that extends from the bottom 22 to a thread break 29 at the start of the bead 24. The unthreaded bead portion extending upwards directly above the thread breakage point 29 forms a smooth gasket sealing region 30.

  As shown in FIG. 3, the sealing relationship between the plug 1 and the bushing 21 in a sufficiently torqued state shows the plug gasket 12 being tightly compressed between the plug gasket pedestal 8 and the bushing sealing region 30. . Notably, the gasket 12 is also constrained axially between the rim lower surface 4 a and the retaining lip 9 upper surface 11. Further, it can be seen that the gasket 12 in the tightened position is in contact with the bushing spiral thread break and the end point 29. The continuous annular upper surface of the thread retaining lip maintains a constant axial spacing from the lower surface 4a of the rim and prevents the gasket 12 from being fitted into the bushing thread 28 at any point. When the plug is loosened as shown in FIG. 4, the gasket retaining lip 9 lifts the plug gasket 12 away from the bushing thread 28 and out of the gasket sealing area 30. This is due to the complete separation of the plug gasket from the surrounding bushing surface, eliminating the common gasket “gripping” and gasket “looping” problems to date.

  In contrast, FIG. 5 shows a typical prior art situation where the prior art plug 40 is loosened from the internally threaded container wall opening neck 41. Here, the plug gasket 42 is seated on a gasket pedestal 43 formed in the diameter of the valley of the plug thread, but the plug thread 44 simply decreases gradually as indicated by reference numeral 45 as it approaches the gasket pedestal 43. Under these prior art conditions, it can be seen that the gasket 42 is hardly supported axially by the taper threads 45 when the plug is removed and returned. As a result, the gasket can be easily trapped between the interengaging closure threads and thus pulled out of the gasket pedestal, severely hindering normal closure functionality.

  The second and third embodiments of the present invention are shown in FIGS. 6 and 7, and FIGS. 8 and 9, respectively, and are described in the first embodiment described with reference to FIGS. Although it is a modified form, the same code | symbol is given to the same component. As shown in FIGS. 6 and 7, an exemplary metal closure plug 60 is cut and rolled from 1.15 mm drum end steel. The gasket holding lip 61 has a thread-like triangular section having a 55 ° included angle, and a radial extension D1 having a smaller diameter than the outer radial extension D2 at the top of the thread 7. And it rolls so that it may become a field parallel to lower surface 4a of plug rim 4. The upper flank 62 of the retaining lip 61 forms a continuous upward and outward surface on the thread 7 continuously. The diameter D3 of the inner root 63 of the lip 61 is smaller than the diameter D4 of the thread valley. The gasket pedestal 64 extends in a flared shape radially outward and upward so that it abuts the rim 4 at approximately the same point where the gasket pedestal 8 abuts the rim in the first embodiment. E. P. D. M, black nitrile, or P.I. E. As shown in FIG. 7, the conventional gasket 12 made of is extended on a gasket pedestal 64 to ensure substantially the same flare shape.

  The effect of the modified geometry of the second embodiment is that the lip 61 has substantially the same radial extension D1-D3 as the lip 9 of the first embodiment, and therefore the first The gasket lifting function and anti-grab function and anti-loop forming function of this embodiment are maintained. The reduced lip diameter allows the closure plug to fit with a larger range of container openings. The flared gasket pedestal 64 has two advantages. First, this gasket pedestal increases the volume of the sealing gasket 12 in the region between the closing plug lip 61 and the gasket sealing region 30 of the container closing bushing 21 and, secondly, the cut that the elongated gasket 12 takes. The head cone increases the contact area between the gasket and the gasket sealing area 30 as the plug is screwed into the bushing 21. This sealing gasket is “feeded” into the volume between the bushing sealing area 30 and the plug pedestal 64 and the rear end of the gasket is initially compressed lower (or not compressed at all). Therefore, the initial contact zone between the gasket and the closing bushing is preferably halfway to the side of the gasket. This is most clearly seen in FIGS. 8 and 9, where the plug threads, rims, and lips 61 are similar in geometry to the embodiment shown in FIGS. 6 and 7, but the plug is suitable. Formed from various plastic materials. The effect of such an increase in contact area and less compression at the rear end of the gasket is to further reduce gasket looping while torqueing the plug.

  Another advantage of the geometry used for the lip 61 is that the geometry reinforces the plug, while the plugs of FIGS. 6 and 7 maintain the equivalent structural integrity while still maintaining the prior art. It is possible to be formed from thinner gauge steel than is used for plugs.

  By using a standard gasket, the lip 61 allows direct contact of the closing bushing wall 23 in the region of the bushing thread break 29 when the plug 60 is sufficiently torqued. If desired, large metal gaskets can be used to prevent contact between such metals.

  FIG. 10 shows a fourth embodiment of the present invention, where the metal plug 66 has a lip 68 of the same geometry as the lip 61 of the second embodiment. The difference is that the peripheral groove 70 is rolled at the base of the lip 68 of the gasket pedestal 72, and the remainder of the gasket pedestal 72 is made cylindrical. This geometry provides the same radial extension of the lip 68 as the lips 9 and 61 of the first to third embodiments, and the groove 70 increases the volume of the gasket 12.

  Various variations or modifications of the gasket retaining plug of the present invention can be made. For example, the closure plug of the first embodiment can be formed from metal, and the second and fourth embodiments can be molded from synthetic plastic resin.

Claims (10)

i) a cylindrical side wall (3) having a helical external thread (7);
ii) a plug rim (4) enlarged in the circumferential direction;
iii) an annular gasket pedestal (64) directly below the plug rim (4);
iv) a closure plug formed with a continuous circumferential gasket retaining lip (61) extending radially outward under said annular gasket pedestal (64),
v) The annular gasket pedestal (64) extends linearly from the base (63) of the gasket holding lip (61) and radially outwards upward so as to contact the plug rim (4). A closure plug, characterized in that   The closure plug according to claim 1, wherein the upper flank (62) of the gasket retaining lip (61) forms a continuous peripheral upward and outward surface on the helical external thread (7). .   The closure plug of claim 2, wherein the annular gasket pedestal (64) has a frustoconical shape.   The gasket holding lip (61) has a radially extending portion (D1) having a smaller diameter than a radially outwardly extending portion (D2) which is the top of the helical external thread (7). The closure plug according to any one of claims 1 to 3.   The diameter (D3) of the root (63) inside the gasket holding lip (61) is smaller than the diameter (D4) of the root of the spiral external thread (7). The closure plug according to one item.   The closure plug (60) according to any one of claims 1 to 5, wherein the closure plug (60) is made of metal or formed by molding a synthetic plastic resin.   3. A closure plug according to claim 2, wherein a resilient sealing gasket (12) extends on the annular gasket pedestal (64) and takes the shape of the annular gasket pedestal (64).   The closure plug according to claim 7, wherein the sealing gasket (12) takes the shape of a truncated cone of the annular gasket pedestal (64).   The sealing gasket (12) is made of E.I. P. D. M, black nitrile butadiene rubber, or P.I. The closure plug according to claim 7, comprising E. In the combination of a closure plug according to claim 7 and an opening in a container wall (20) having a bushing (21)
The bushing (21) has a cylindrical wall (23) with a helical internal thread (28) and a smooth gasket sealing area (30) extending upwards,
The sealing gasket (12) is compressed in a substantially radial direction between the gasket sealing region (30) and the annular gasket pedestal (64), and is in a state close to the spiral internal thread (28). A combination characterized by being.

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