This invention relates to plastic containers of the type comprising a pail and a lid which sealingly fits onto the pail without the need for a gasket and further wherein the container provides multiple lid locks, one of which is removed by tearing off part of the lid in the opening procedure.
Plastic containers comprising the combination of an open top pail and a lock-on lid or closure are well known and have been in commercial use for shipping and merchandising various products in the United States for many years. The word “lock”, as used in this product area, refers to an undercut-based snap fit between the pail and lid which inhibits removal of the lid, sometimes strongly enough to require the use of a tool or physical alteration of the lid to achieve removal.
Plastic containers of this type have largely supplanted metal containers in many areas including adhesives, food products, paint, wallboard paste, spackling, driveway sealant and other products. They are durable and largely undentable, particularly when made of high density polyethylene, and not subject to corrosion.
The pail and lid are typically injection molded of a suitable material such as high density polyethylene or polypropylene. The seal between the pail and the lid can be achieved by providing a compressible O-ring gasket but this is another part to make and install and, therefore, adds to cost. One multiple-lock container and closure structure is shown in U.S. Pat. No. 5,730,309 to Jiradejnunt et al. This patent discloses a plastic container with a flanged rim that bears against seal rings molded into the end of the lid channel and three locks, two of which are removed in the opening procedure, which procedure involves tearing away the lower part of the lid skirt. The lid thereafter provides only a weak seal and is difficult to remove because the newly-formed bottom of the lid skirt is too close to a pail sidewall feature that forms part of the middle lock.
The present invention provides a plastic container comprising the combination of an open-top flangeless pail and a lid, both preferably made of injection molded plastic such as polyethylene or polypropylene, wherein a strong lock and a good seal is provided between the pail and the lid without the need for either a gasket or special features such as rim beads and notches on the top of the pail rim or in the lid channel. In this invention, the good seal is preserved even after the opening procedure has been performed; i.e., after removal of the lower part of the lid skirt. In addition, the lid can be readily removed by hand after the initial opening procedure.
In general, these improvements are achieved by providing a pail with a flangeless top rim that wedge-fits into a narrow inverted peripheral channel in the lid and by providing a double-locking structure involving cooperating elements on the container sidewall and lid skirt wherein a top lock helps to maintain the rim seal both before and after the initial opening procedure, and the removal of a bottom lock exposes a newly-formed annular lid skirt edge in a position that affords easy access to the user's fingers for subsequent repeated removal purposes.
Removal of the lower lock is achieved by means of a tear groove that weakens the lid skirt sufficiently to allow removal of the bottom annular ring portion, thereby exposing the new skirt edge mentioned above. The groove is strategically located to provide the advantages detailed above.
In an illustrative embodiment, arrows, indicia or the like are molded into the lid to surface to direct the user to apply a lifting force in certain areas to remove the lid from the container once the lid skirt is torn. In the illustrated embodiment, there are three such indicia in the forms of arrows with the legend “LIFT” molded into the top deck of the lid thereby to eliminate the need for a printing function or the application of a decal. However, both of these alternatives as well as other alternatives, while not preferred, are useable in accordance with the more detailed aspects of the present invention.
Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
Referring to
The pail 12, which in this instance is a 3½ Gallon Pail but can be Made in any of a variety of other larger and smaller sizes, comprises a slightly tapered cylindrical sidewall 16 extending upwardly to an enlarged diameter collar 18 which is integral with, but is spaced outwardly from, the wall 16 by ribs 32 and which lies below the upper rim portion 26 as best shown in
As shown in
Looking at the lid 14, it comprises an inverted U-shaped peripheral channel portion 34 defining a downwardly opening and radially narrow, internal channel 36 which snugly and sealingly; i.e., wedgingly receives the top rim portion 26 of the pail 12 therein. The inverted U-shaped channel peripheral portion 34 comprises an outer wall 38 and a downwardly extending annular inner wall 40 having circumferentially spaced reinforcing ribs 42 as shown in
In accordance with the invention, an upper lock comprises the combination of the bead 28 on the pail sidewall 16 and three evenly circumferentially spaced semi-annular locking segments 48 forming undercuts 50 on the inside surface of the outer skirt 52 of the lid. When the lid 14 is firmly attached to and seated on the pail 12 the bead 28 fits within the undercuts 50 of the three locking segments 48 to draw the lid 14 onto the flange 26 of the pail 12. In other words, the distance from the top of rim 26 to the lock bead 28 matches the distance from the bottom surface (seen as the top in
The lid 14 is molded with a long skirt including the upper wall 30 and a lower portion 52 separated by an interior, circumferential tear groove 56 which is made thin and weak enough to allow the lower portion 52 to be manually torn off. A starter tab 60 is provided to facilitate tearing. Note that the tear groove 56 is well below; i.e., about 1 to 2 inches, by the lock bead 28 which fits into the undercut notch 50 in the inner surface of the lid's upper skirt. Further, the lid skirt stands well out from the container sidewall at the tear groove 56. This gives a large handhold to grasp the outwardly flared upper skirt at a newly formed annular edge after the lower skirt 52 is removed as shown in the top part of
Further in accordance with the invention, indicia 58 comprising the combination of outwardly directed arrows and the legend “LIFT” are molded into the top surface of the deck 44 to indicate exactly where the locking segments 48 are located such that a user of the pail may apply a lifting force in this area after the removal of the lower skirt 52 has been achieved as hereinafter described. Other legends providing similar information may be used.
The lower skirt portion of the lid 14 comprises the depending skirt 52 terminating an undercut 54 which fits over and receives the bead 30 on the lower locking collar portion 18 of the pail sidewall 16 when the lid 14 is placed on pail 12 and firmly seated. However, a circumferentially extending weakened area provided by a notch 56 allows the lower portion of the skirt 52 to be torn away. A starter tab 60 is provided as shown in
In operation, the pail 12 and lid 14 are typically injection molded at a suitable plant site. Once they are shipped to the customer, the container 10 is filled with product (not shown) and the lid 14 is seated on the container 12 such that the upper rim portion 26 of the container sidewall extends fully and contactingly into the channel 36. A pinch seal is provided by bump 27 if necessary, but a wedge seal is generally sufficient. There is a contact seal on both sides of the sidewall 16 and on the top of the rim. The upper lock 28, 50 snaps into place and the lower lock 30, 54 also snaps into place to securely hold the sealed lid 14 on the container 12. Similar containers 10 can be stacked and shipped in the product filled condition without fear of leakage or the ingestion of unwanted air into the interior of the container 10.
When the user is ready to gain access to the product, the starter tab 60 is broken away from the lid portion 52 and the lower skirt 52 is removed. This eliminates the lower lock 30, 54 and also provides evidence that the container 10 has been opened. Once the lower skirt 52 and the lower lock 30, 54, have been removed, the only lock holding the lid 14 to the pail 12 is the segmented upper lock 28, 50. This lock is strong enough to maintain the rim seal, but is relatively easily overcome without the use of tools by lifting the newly-revealed edge of the lid 14 immediately adjacent the indicia arrows 58. The plastic pail and lid combination is sufficiently flexible to permit the lid rim channel sidewall 38 below the lock 28 to be flexed outwardly and this overcomes the lock and permits the lid 14 to be removed from the pail 12. It also permits the lid 14 to be relocated and relocked onto the pail 12 using the three 120° spaced locks 28, 50. An audible “snap” occurs when the lid 14 is fully re-seated, telling the user that a good seal has been achieved. The snap comes from the undercut groove 56 receiving the bead 28.
Looking now to
The pail 60 has an unflanged top rim 64 and an outwardly extending annular lock bead 66 about an inch below the rim, generally the same as the bead 28 in the embodiment of
The lid 62 has a recessed central deck 76, a raised peripheral structure 78 with an annular interior wall 80 that, when the lid is applied to the pail, fits tightly against the inner pail sidewall surface at the diametrically enlarged upper portion, with the bottom edge of the wall resting on the shoulder 68. An undercut groove 84 is spaced at the bottom of the receiving channel 82 to provide a receiving element for the sidewall bead 66. The configuration is such as to produce an audible, snap-fit function and the location is such as to provide the necessary upper lock only when the top pail rim is fully seated into the lid channel 82.
A tear groove 86 is located below the undercut groove 84 in an area where the lid skirt flares out, providing space between it and the pail sidewall. A starter tab shown in
In this embodiment, the distance from the top lock bead 66 to the top of the rim 64 is again such as to provide the snap fit described above, between the bead 66 and the undercut 84 in the lid skirt. Once again, a lower lock is provided between the lid skirt at 88 and the sloped ring 70 on the container sidewall below the shoulder 68. The tear groove 86 is located between the two lock rings.
As shown in
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.
This application is a continuation of co-pending U.S. patent application Ser. No. 14/178,401 filed Feb. 12, 2014, which is a continuation-in-part of U.S. patent application Ser. No. 12/552,612, filed Sep. 2, 2009, (now abandoned) which is a continuation-in-part of U.S. patent application Ser. No. 11/880,524 filed Jul. 23, 2007, (now abandoned).
Number | Date | Country | |
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Parent | 14178401 | Feb 2014 | US |
Child | 14682170 | US |
Number | Date | Country | |
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Parent | 12552612 | Sep 2009 | US |
Child | 14178401 | US | |
Parent | 11880524 | Jul 2007 | US |
Child | 12552612 | US |