Patent Application
20090026203
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 combination has locking features which hold the lid onto the pail.
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. They have largely supplanted metal containers in many areas including adhesives, food products and paint. The pail and lid are typically injection molded of a suitable polymeric 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 or by molding a notch in the top of the pail rim flange and providing a corresponding bead in the underside of the inverted U-shaped channel of the lid which receives the rim bead of the pail. This later structure is described in the published U.S. Application US 2002/0148846. Still another seal structure is illustrated in the expired patent to Richard Landis, U.S. Pat. No. 4,418,833.
The present invention provides a container comprising the combination of an open top pail and a lid, both preferably made of injection molded plastic such as polypropylene, wherein 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 in the top of the pail.
In general, this is achieved by providing a pail with a flangeless top rim, and a lid having a narrow inverted U-shaped peripheral channel defined by an inner annular ring which is reinforced by radial ribs.
In addition, and in accordance with a preferred embodiment of the invention, multiple locks are provided for securing the lid to the pail wherein said multiple locks comprise an upper lock made up of comprising a continuous bead on the outer wall of the container immediately below the top edge and a plurality of widely circumferentially spaced locking segments on the inside surface of the inverted U-shaped channel formed by the lid to provide widely spaced, discrete undercuts which receive the pail sidewall bead and lock thereto. The second of the multiple locks is provided lower down on the container sidewall and at the bottom of the outer skirt of the lid. This second lower lock is preferably removable by forming a circumferentially extending weakened area in the inside of the lid skirt such that the portion of the skirt below the weakened are can be torn away leaving only the upper lock in place. This manipulation is typically carried out by the end user.
In the preferred from the upper lock is provided in two, three or four discrete and circumferentially spaced areas and indicia are carried on the top surface of the lid to show where the locking segments are located and to direct the user to apply a lifting force in that area to remove the lid from the container once the tear band has been pulled away. 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 Figures there is shown an all plastic container 10 comprising the combination of a tapered cylindrical plastic pail 12 and an injection molded lock-on plastic lid 14. In this illustrative embodiment the pail 12 and lid 14 are both injection molded of polypropylene but other materials such as high density polyethylene may be used as alternatives.
The pail 12, which in this instance is a 3½ gallon pail but can be made in a variety of other sizes, comprises a tapered cylindrical side wall 16 extending upwardly to an enlarged diameter collar 18 which is integral with the wall 16 and 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 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 side wall 16 and three evenly circumferentially spaced 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 hold the lid 14 on the pail 12.
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 tear band 52 has been achieved as hereinafter described. Similar equivalent legends 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 side wall 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 side wall extends fully and contactingly into the channel 36 and is sealed by the tight fit therein. There is a contact seal on both sides of the sidewall 16. 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 tear band portion of skirt 52 is removed. This eliminates the lower lock 30, 54 and also provides evidence that the container 10 has been opened. Once the tear band portion of skirt 52 and the lower lock 30, 54, have been removed, the only locks holding the lid 14 to the pail 12 are the upper three locks 28, 50. These locks are relatively easily overcome without the use of tools by lifting the revealed edge of the lid 14 immediately adjacent the indicia arrows 58. The polypropylene pail and lid combination is sufficiently flexible to permit the lid rim channel sidewall 38 to be flexed outwardly in 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.
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.
