Patent Document

FIELD OF THE INVENTION  
       [0001]     This invention relates to tamper-evident molded plastic containers and closures and particularly to an arrangement wherein the closure is provided with a tear band which is manually removed to facilitate opening the container for access to the content thereof The closure of the present invention remains attached to the container even after removal of the tear band and may be securely re-applied to the container albeit with no further tamper-evident characteristic.  
       BACKGROUND  
       [0002]     Molded plastic container and closure combinations, typically but not exclusively made of high density polyethylene, have become extremely popular for use in shipping, storing and marketing a variety of products from sealants and paints to food products in both individual consumer and bulk quantities. It is known to provide such container/closure combinations with tamper evident characteristics through one or more of an assortment of locking structures including those which are partially or fully disabled by way of tear strips or tear bands. The typical tear band closure is provided with at least one locking structure and a tear line which allows a portion of the outside peripheral skirt of the closure to be manually torn away to fully or partially remove or disable the locking structure. The removal of the tear band provides visual evidence that the closure has been manipulated for removal purposes. After the removal of the tear band, the closure may be completely detached from the container and either discarded or reused.  
         [0003]     The term “locking” is used in this description to refer to inter-fitting plastic structures such as undercuts and flanges which mate to impede or resist the removal of the closure from the container; i.e. the term does not infer the need for keys or combinations or absolute security.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention provides a molded plastic container and closure combination having a number of highly desirable features including the security of a tamper-evident closure in a combination that further provides a hinged closure which remains connected to the container and may be securely re-applied even after the tear band has been removed to facilitate access to the contents. Such container is particularly useful for the shipment, storage and marketing of products such as pet food which are not fully consumed in a single serving or distribution but may be doled out over a period of days or weeks.  
         [0005]     As is hereinafter described, the container/closure combination of the present invention provides a closure which is readily manually altered by removal of a tear band for opening but which provides for easy and secure closing and reopening after removal of the tear band. Further features include a structure which enhances stackability by transferring stacking loads through the closure structure to the container sidewall. A further feature of the present invention is the production of substantial hoop strength and structural stability in the container as a result of various reinforcing side wall structures including a bail ear box band. A further feature of the invention is the provision of means to facilitate lifting and tipping of the container for the purpose of pouring contents therefrom during use.  
         [0006]     In general, the invention comprises a molded plastic container and closure combination wherein the container has a bottom and a side wall structure which terminates in an open top defined by an out-turned peripheral lip. The container side wall structure is further provided with at least one outwardly projecting reinforcing rib or flange which is integral with the side wall structure, parallel to the peripheral lip and spaced below the lip by a small distance, typically about 1.5 inch. The combination further comprises a molded plastic closure having a deck portion which approximates the shape and size of the open container top and an inverted U-shaped peripheral channel around the deck portion and defined by parallel spaced inner and outer walls. A first undercut is formed in the outer wall near the top of the inverted channel to mate with the peripheral lip of the container to provide the primary lock both before and after operation of the tear band as hereinafter described. A second undercut is formed below the first undercut to mate with a projecting rib or flange on the container side wall thereby to provide a second lock securing the closure to the container before the tear band is removed.  
         [0007]     A pair of spaced-parallel tear paths are defined in the side wall between the first and second undercuts and extend continuously but not fully around the closure body, terminating in spaced, mirror-image, C-shaped openings on the outer wall to define a hinge area, the effective hinge point of which lies well below the container lip when the closure is fully sealed. This fully engages the upper lock to secure the closure to the container without the need for latches after the tear band is removed.  
         [0008]     In the preferred embodiment, the C-shaped openings define two mirror-image starting tabs which are preferably ribbed so that either a right- or left-handed person can grasp the end of the tear band and remove it by manual separation along the parallel-spaced tear paths. This operation leaves the closure attached to the container but in a condition to be hinged away from the open top of the container about the hinge area described above. After removal of material from the container, the closure can be securely reattached to the container to maintain the quality and usability of the container contents.  
         [0009]     In the preferred embodiment, the inside wall of the container is provided with a step approximately one inch below the peripheral lip; this dimension can, of course, vary with the particular design. The inner wall of the closure fits snugly against the inside wall of the container and sits atop the step so as to transfer stacking loads through the closure to the container side wall when stacked in a vertical orientation. The container and closure combination described herein is essentially rectangular in cross-sectional configuration with smoothly curving transitions at the junctions of the flat side wall segments. To ensure non-interfering operation of the closure, the inner wall is preferably truncated or at least partially removed in the curved areas as hereinafter described.  
         [0010]     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. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:  
         [0012]      FIG. 1  is a perspective view of a molded plastic container and closure combination embodying the invention;  
         [0013]      FIG. 2  is a further perspective view of the container and closure combination of  FIG. 1  from a different angle;  
         [0014]      FIG. 3  is a further perspective view of the container and closure combination of  FIG. 1  after removal of the tear band and hinging of the closure to the open position;  
         [0015]      FIG. 4  is a sectional view through the closure and container side wall structure showing the relationship of various locking features;  
         [0016]      FIG. 5  is another sectional view through the container side wall and closure illustrating the operation of the hinge;  
         [0017]      FIG. 6  is a partial perspective illustrating details of the closure interior in the curved area thereof; and  
         [0018]      FIG. 7  is a plan view of the bottom of the container shown in  FIGS. 1-6 . 
     
    
     DETAILED DESCRIPTION  
       [0019]     Referring to the drawing, there is shown an assembly  10  of an injection molded plastic container  12  and a tamper evident closure  14  which can be secured to the container  12  to control access to the contents of the container  12  during shipment, storage and use. The container  12  and closure  14  of the illustrative embodiment are preferably injection molded of high density polyethylene (HDPE) or polypropylene (PP) but many other materials may also be used depending on the desired physical qualities of the end product. HDPE or PP are preferred because they are widely available in pellet form and provide the stiffness and strength associated with industrial quality containers. The illustrative example is a four-gallon container but this is merely representative of the various sizes of the containers in which the invention may be embodied; i.e., it is anticipated that the benefit to the invention may be realized in any container from about 1 to 100 liters in capacity.  
         [0020]     The container  12  is essentially rectangular in cross-sectional configuration such that the side wall structure  14  has both relatively straight and relatively curved portions. The side wall structure  14  tapers upwardly from the bottom panel  16  to an open top defined by an out-turned peripheral lip  30 . The bottom is protected by means of a peripheral flange or foot  18  which is interrupted at opposite smoothly curved gripping portions  20  and  22  best shown in  FIGS. 1 and 7 . The container is provided with a formed wire bail  24  having attachment points on opposite sides of a bail band  26  which is integrally formed with but stands outwardly from the side wall structure  14  approximately two inches below the peripheral lip  30 . The structure  26  adds hoop strength and works in combination with the box ribs  30  to provide bail ears which are used to attach the bail  24  as shown by the dotted lines in  FIGS. 2 and 3 . An extruded plastic grip  28  is mounted on the wire bail  24  to provide user comfort. As best shown in  FIGS. 4 and 5 , the out-turned peripheral lip  30  defines the open top of the container side wall structure  14 . Spaced below and parallel to the lip  30  is a first outwardly and downwardly projecting side wall reinforcing rib or flange  32 . Approximately ⅝ inch below the flange  32  is a second parallel flange  34 . The flanges  32  and  34  also add hoop strength to the container side wall. In addition, the flange  32  provides a locking function as hereinafter explained.  
         [0021]     The side wall band  26  is spaced below the lower of the two flanges  32  and  34  as shown. All dimensions are by way of example.  
         [0022]     The closure  14  has a recessed central deck  38  approximately the shape and size of the open top of the container  12 . Closure  14  also has an inverted U-shaped peripheral channel defined by the outer wall  40  and the inner wall  42 . The inverted U-shaped channel receives the peripheral lip  30  of the container side wall  14  as shown in  FIGS. 4 and 5 . The inner wall  42  fits snugly against the inside surface of the side wall structure  14  and rests atop a shallow step  37  which is formed in the side wall structure for the purpose of transferring stacking loads through the closure to the container side wall structure  14  when two or more containers are stacked atop one another. The height of the inner wall  42  corresponds to the dimension below the lip  30  where the step  37  is formed.  
         [0023]     The outer wall  40 , often referred to as the “skirt” of the closure  14 , has a first undercut  43  formed just below the top of the inverted U-shaped channel to cooperate with the annular peripheral lid  30  to help secure the closure  14  to the container  12 . A second undercut  44  is formed at a distance below the first undercut  43  to cooperate with the flange  32  in providing a second locking mechanism to help secure the closure  14  to the container  12 . Between the two undercuts  43  and  44 , a pair of spaced parallel tear paths  46  and  48  extend continuously but not fully around the periphery of the closure as shown in  FIG. 1 , said tear path terminating at oppositely similar C-shaped openings  52  and  54  between which is located a hinge area  56 . Creases  58  are formed in the hinge area well below the plane of the lip  30  to assist in hinging the closure  14  relative to the container  12  after the tear band  50  defined by the two spaced tear paths  46  and  48  is removed. The tear tabs  60  and  62  are ribbed or scored to enhance gripping. The tear paths  46  and  48  are areas of reduced thickness or may be formed by perforations or the like in as will be apparent to persons skilled in the plastic container art.  
         [0024]     Once the tear band  50  has been removed between the tear paths  46  and  48 , the lower lock formed by the flange  32  in the undercut  44  is no longer in effect as a tamper-evident feature, i.e., only the upper lock made up of the cooperating features  30  and  43  remains fully in place. However, the lower lock continues to connect or tether the closure to the container. Because the plastic material from which the closure and container are made is somewhat pliable, the upper lock may be manually overcome to hinge and open the closure relative to the container body as shown in  FIG. 5 . Because of the lower hinge point  58 , it is necessary to avoid interference at the curved corners near the front of the closure during opening and closing of the closure  14  relative to container  12 . This is accomplished by means of truncated sections  68  and  70  of the inner wall  42  in the areas of the corners as shown in  FIG. 6 . Because the deck  38  is preferably recessed, a second inverted U-shaped channel is formed between the deck  38  and the inner wall  42  as shown in  FIG. 4 . Strengthening ribs  72  are preferably formed at peripherally spaced locations in this area. As shown in  FIG. 7 , recesses  64  and  66  are formed in the bottom  16  inboard of the smooth gripping areas  20  and  22  to provide finger slots to assist in tipping the container  12  to pour the contents therefrom. It will be noted that the axis of separation of the recesses  64  and  66  is orthogonal to an axis through the attachment points of the bail.  
         [0025]     In operation, the purveyor of goods. to be shipped in the container fills the container  12  and applies the closure  14  thereto in integral form causing both the upper and lower locks to take effect. When the end user is ready to remove some or all of the contents of the container  12 , he removes the tear band  50  by way of the starting ribbed tab  60  and  62  and the tear paths  46  and  48  as described above. The closure  14  may then be hingedly removed from the top of the container  12  while remaining attached to the container for convenience. After removing some or all of the contents of the container  12  the closure  14  may be reattached to secure and preserve the remaining content.  
         [0026]     The closure and container may be manufactured in contrasting or coordinating colors from either identity polyethylene or a variety of other materials. The sidewall structures  14  readily receive labels and informative printed matter, the smooth continuous flat surfaces being particularly efficacious as “billboard” space which is important to marketeers.  
         [0027]     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.

Technology Category: b