Abstract:
The combination of a reusable lid and a container, the lid being provided with locking tabs and the container being provided with openings designed to accept the locking tabs and to make an interlocking connection by relatively rotating the lid and container. A latch element is formed on the lid for engagement with one of a plurality of cooperating catch elements formed on the container. The engaged catch element prevents removal of the lid from the container until the latch element is depressed inwardly far enough to allow the lid to be turned to a position in which the tabs may be removed from the openings.

Description:
This invention relates to sealed containers such as a bucket or pail having a removable lid or cover. More particularly this invention is concerned with providing containers having covers or lids that are capable of providing a sealed closure to preserve the contents of the containers and also can be repeatedly assembled to and removed from the containers. 
     BACKGROUND OF THE INVENTION 
     Multi-gallon capacity plastic containers having removable plastic lids or covers are widely used for the storage and transportation of liquid and solid materials, e.g., materials in granular or powder form. For some applications, the lids may be single use, i.e. they may be thrown away after the container has been opened, typically because all of the contents of the container are dispensed after the lid is removed. For other applications a reusable lid must be provided, for example, when it is desired to use only a portion of the contents of the container and to then store the partially filled container for future use. In many cases the reusable lid may have to make a secure fit, so as to prevent leaking of the contents of the container after the lid has been reapplied. Having a secure fit is of particular concern if the container is filled with material that is toxic or irritating to the skin and is used in or around a residence where small children are present, since their curiosity may cause them to remove the lid to view the contents of the container. Safety concerns demand that reusable lids not only make a substantially leak-proof fit with the container but also be difficult for children to remove, either accidentally or purposefully. However, as practical matter, commercial production of containers and lids that satisfy existing safety concerns necessarily requires control of manufacturing costs. 
     SUMMARY OF THE INVENTION 
     One object of the invention is to provide an improved and reusable lid for a container which can be re-applied repeatedly to provide a secure closure that prevents loss of the contents from the container. 
     Another object of the invention is to provide an improved reusable closure means for containers which is difficult for small children to remove yet is designed to securely seal the container so as to prevent loss of its contents. 
     A further object of the invention is to provide a reusable lid for a container for solids in powder or granular form which provides a secure seal regardless of the number of times the lid is re-applied. 
     In a preferred embodiment of the invention, the foregoing objects are attained by providing a container/lid combination wherein the upper end of the container has a peripheral skirt that is spaced from the wall of the container and has a plurality of openings, and a lid having a plurality of lock tabs that are received in the openings and serve to lock the lid to the container when the lid is rotated relatively to the container. In a preferred embodiment of the invention, each of the openings is elongated circumferentially of the container and comprise a relatively wide portion and relatively narrow portion, and the lock tabs comprise a depending body portion and a tapered lock portion at the bottom of the body portion. The lock tabs are sized so that their tapered lock portions can pass through the relatively wide portions of the openings and their body portions can fit in the relatively narrow portions of the openings. With this arrangement, the lid can be locked to the container by inserting the tabs through the relatively wide portions of the openings, and then rotating the lid so as to move the body portions of the tabs into the relatively narrow portions of the openings, whereupon the tapered lock portions of the tabs are engaged with the container and serve to secure the lid to the container. In an alternate embodiment, the openings on the container are rectangular and the tabs are shaped so as to have a depending body portion and a laterally-extending bayonet or arm portion that is spaced from the rim and is adapted to make a locking engagement with the container&#39;s skirt when the lid is rotated relative to the container. In both embodiments, it is preferred to provide a plurality of mutually spaced catch means on the exterior of the container and a latch means on the lid that is adapted to interlock with one of the catch means and thereby securely retain the lid on the container. The latch means is an integral part of the lid and is formed it can be deformed in a radial direction by a manually pressing action so as to disengage it from the associated catch means. 
     Other features and advantages of the invention are set forth in or rendered obvious by the following detailed description of a preferred embodiment of the invention, which is to be considered together with the drawings hereinafter described. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation of a lid and container lid constituting a preferred embodiment of the invention; 
         FIG. 2  is side elevation of the lid of  FIG. 1 ; 
         FIG. 3  is a side elevation of the container of  FIG. 1 ; 
         FIG. 4  is a plan view of the same lid; 
         FIG. 5  is a bottom view of the same lid; 
         FIGS. 6 and 7  are cross-sectional views taken along lines  6 — 6  and  7 — 7  of  FIG. 4 ; 
         FIG. 8  is a plan view of the container; 
         FIG. 9  is a bottom view of the container; 
         FIGS. 10 and 11  are cross-sections view taken along lines  10 — 10  and  11 — 11  of  FIG. 8 ; 
         FIG. 12  is a fragmentary side view of the lid with a modified embodiment of locking tab; 
         FIG. 13  is a fragmentary sectional view taken along line  13 — 13  of  FIG. 12 ; 
         FIG. 14  is a fragmentary plan view of the container showing a modified form of opening for receiving a locking tab; and 
         FIG. 15  is a fragmentary sectional view taken along line  15 — 15  of FIG.  14 . 
     
    
    
     In the drawings, like parts and elements thereof are identified by like numerals. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1-3 , a preferred embodiment of the invention comprises a circular lid  2  and a container  4  of circular cross-sectional configuration. Both the lid and the pail are molded of a plastic material that is relatively stiff yet resilient enough to allow limited flexing, e.g., polyethylene or another moldable thermoplastic resin, preferably a relatively high density thermoplastic material. 
     As seen best in  FIGS. 4-7 , lid  2  is formed with a main body portion or crown  6  and a surrounding rim comprising an inner wall  8  that projects upwardly from the level of crown  6 , a peripheral flange  10  attached to the upper end of wall  8 , an intermediate wall  12  attached to and depending from flange  10 , and an outer wall  14  attached to flange  10 . Preferably, but not necessarily, outer wall  14  is slanted downwardly and outwardly as shown in  FIGS. 1 ,  2  and  6 . An annular channel  18  is formed between intermediate wall  12  and outer wall  14  and is sized to accommodate the upper end of container  4 , as explained hereinafter. Intermediate wall  12  also functions to strengthen the rim. Preferably but not necessarily, the bottom edges  20  and  22  of walls  12  and  14  respectively project below the crown  6 , as shown in FIG.  6 . The upper surface of flange  10  is interrupted by several raised sections  24  having radially extending webs  26  at their opposite ends. Preferably the lid has four such sections as shown. These raise sections facilitate attachment and detachment of the lid relative to the container while still permitting upstanding inner wall  8  to serve as an alignment guide to facilitate the stacking of another container on top of the lid. 
     The lid also has a plurality of like locking tabs  30  attached to and depending from outer wall  14 . Each tab  30  comprises a body portion  32  which is generally rectangular in horizontal cross-section, with a width (measured circumferentially of the lid) that is substantially greater than its thickness (measure radially of the lid). The bottom end portion  34  of each tab is enlarged so as to form an upwardly facing surface  36  that functions as a shoulder or lip for locking the tab to the container. Referring to  FIG. 5 , preferably the bottom end portion of each locking tab is tapered (as viewed radially of the lid), so as to facilitate attachment to the container in the manner explained hereinafter. Preferably the tabs are equally spaced about the lid to facilitate attachment of the lid to the container. 
     Referring to  FIGS. 1 ,  2 ,  4 ,  5  and  7  the outer wall  14  has a vertically extending cut  40  therein, and adjacent that cut the wall  14  is formed with a projecting portion  42  that functions as a latch member that cooperates with a catch on the container to that prevent rotation of the lid in a direction to release it from the container. As is evident from the  FIGS. 1 and 2 , in side elevation latch member  42  has a generally rectangular configuration, having one end  44  demarcated by cut  20 , an opposite end  46  and a top  47  that are integral with wall  14 , and a bottom edge that is a continuation of the bottom edge of wall  14 . As best seen in  FIGS. 4 ,  5  and  7 , the end  44  of latch member  42  projects radially outward beyond the outer surface of the adjacent portion of wall  14  on the opposite side of cut  40 , and the remainder of latch member  42  is canted inwardly to where its end  46  is joined to wall  14 . As described hereinafter in greater detail, the end  44  of latch member  42  is the part that provides the locking action. In this connection, it is to be appreciated that since the lid is made of a plastic such as high density polystyrene, the latch member  42  has a certain degree of flexibility, so that its end  44  can be made flush with the adjacent end of wall  14  by manually pressing it radially inward toward the lid&#39;s crown portion  6 . 
     Referring to  FIGS. 1 ,  3 , and  8 - 11 , the container  4  has an open top end  48  and a closed bottom defined by a circular side wall  50  and a bottom wall  52 . To facilitate stacking, it is preferred that the container side wall be tapered as shown so as to have a smaller diameter at its bottom end. Adjacent to its open top end, the container is formed with a laterally extending annular flange  54  and a short depending side wall  56  at the outer edge of flange  54  that functions as a skirt. Preferably, but not necessarily, two diametrically opposed portions of wall  56  bulge outwardly, as shown at  58 , so as to provide an increased space between it and side wall  50  for insertion of a person&#39;s fingers, thereby permitting those portions to function as grips or handles for lifting the container. Also preferably, but not necessarily, wall  56  is slanted downwardly and outwardly as shown in  FIGS. 1 and 3 . 
     Still referring to  FIGS. 8-11 , a plurality of openings identified generally at  62  are formed in flange  54  to accommodate locking tabs  30  of the container. Openings  62  are elongated circumferentially of flange  54  and comprise a first relatively wide portion  66  and a second relatively narrow portion  68 . The length (circumferential dimension) and width (radial dimension) of each portion  66  is slightly greater, e.g., {fraction (1/16)} th  inch greater, than the corresponding dimension of the enlarged bottom ends of tabs  30 . The narrow portions  68  of the openings have a length slightly greater than the corresponding dimension of tabs  30 , while their width is less than the width of the enlarged bottom ends of tabs  30  but slightly greater than the body portions of tabs  30 . 
     The lid is secured to the container by (a) placing the lid on the container so that its locking tabs are aligned with the relatively wide portions of opening  62 , (b) inserting the tabs into the openings so that their relatively wide bottom portions are below the flange  54 , and then rotating the lid so as to move the tabs into the narrow portions of openings  62 , whereupon the shoulders  36  of the enlarged bottom ends of the locking tabs extend beneath adjacent portions of flange  54  and thereby prevent the lid from being lifted off of the container. The length (vertical dimension) of the locking tabs and the vertical position of shoulders  36  on the tabs are set so that the shoulders  36  will make a frictional engagement with the underside of flange  54  just sufficient to resist relative rotation of the lid in an unlocking direction in the absence of a manually applied turning force and also so that the liner tightly engages the upper end  48  of the pail, thereby assuring a tight seal. 
     As shown in  FIGS. 1 ,  3 ,  8 , and  11 , the lid/container combination provided by this invention also includes a plurality of upstanding projections  70  on the upper side of flange  54  that function as catches for latch member  42 . Projections  70  are located close to the outer periphery of flange  54  and intermediate openings  62 . Preferably, as shown in  FIG. 8 , projections  70  are located near the relatively wide portions of openings  62 . The projections have a tapered vertically extending leading surface  72  and a right angle, substantially radially-extending trailing surface  74 . The height of projections  70  is less than the corresponding dimension of latch member  42 , as shown, so as to facilitate releasing the latch member. Preferably the height of projection  70  is equal to or less than one half the corresponding dimension of latch member  42 . When the lid is applied to the container and rotated in the direction required to cause tabs  30  to interlock with flange  54  as described above, the leading end  46  of latch member  42  will pass by the nearest projection  70  and as the rotation continues, latch member  42  will be cammed inwardly by the adjacent projection, causing its end  44  to pass by the trailing surface  74  of the projection, whereupon the inherent resiliency of the tab member will cause it to return to its original outward projecting where it will be flush with or protrude outwardly of projection  70 . Consequently if now an effort is made to rotate the lid in the opposite direction so that it can be released form the container, the projection  70  will intercept latch member  42  and thereby prevent unlocking of the lid from the container. However, the lid can be unlocked by simply depressing latch member inwardly far enough for it to be able to clear the adjacent projection when an effort is made to rotate the lid so as align the locking tabs with the large portions of the keyhole shaped openings  62 . 
       FIGS. 12-15  illustrate features of an alternative embodiment of the invention. These figures do not illustrate a complete lid and container, but it is to be understood that, except as otherwise disclosed hereinafter, the features shown in  FIGS. 12-15  relate to a lid and container that are the same as those shown in  FIGS. 1-11 . As shown in  FIG. 12 , lid  2 A has locking tabs  30 A in the form of a body portion  80  that is integral with and depends from the lid&#39;s outer wall  12  and has at its bottom end a sidewise-extending arm  82  that functions as a bayonet. Body portion  80  and bayonet arm  82  have the same thickness (the dimension measured radially of the lid). Each bayonet  82  is formed so as to provide a gap  84  between its upper surface and the lower edge  20  of outer lid wall  12 . The container  2 A differs from container  2  in that the openings  62  are replaced by rectangular openings  62 A. The width (radial dimension) of each opening  62 A is slightly greater than the thickness of tabs  30   a , while the length of the each opening  62 A (the dimension measured circumferentially of the container) is slightly greater than the corresponding dimension (width) of the bottom end of the locking tabs. Preferably the openings  62   a  are sized so as to provide clearances of {fraction (1/32)}-{fraction (1/16)} inch for tabs  30 A. 
     The alternative embodiment represented in  FIGS. 12-16  is attached to the container by aligning tabs  30 A with openings  62 A, inserting the tabs in those openings, and then rotating the lid relative to the container in the direction (clockwise as viewed in  FIG. 14 ) required to cause the bayonets arms to extend beneath adjacent portions of flange  54 . Preferably the gap  84  between each bayonet arm and the adjacent bottom edge of the lid&#39;s side wall  12  is substantially the same as or only slightly larger (about 0.005″ greater) than the thickness of the flange  54 , whereby the bayonets arms will make a frictional engagement with the flange that is sufficient to prevent the lid from rotating relative to the container in the absence of a manually applied turning force and also assures that the lid will engage the upper end  48  of the container so as to provide a tight seal. Preferably this alternative embodiment includes the latch elements  42  and catches  70  of illustrated in  FIGS. 1 ,  2 ,  4 ,  5 , and  8 - 11 , and those elements operate in the same way to releasably lock the lid to the container. Although this alternative embodiment offers substantially the same advantages, the embodiment of  FIGS. 1-10  is preferred since the locking tabs  30  are easier to form by injection molding than the tabs  30 A and also because they provide a more secure locking engagement with the container. 
     The invention is susceptible of a number of variations and modifications. Thus, for example, the container and lid may be modified to accommodate a liquid rather than a solid material in granular or powder form. For such application, a tight sealing relationship between the lid and the container may be further assured by inserting a resilient sealing ring (not shown) in channel  18 . Preferably the sealing ring is an O-ring sized so as to be engaged and compressed by the upper edge of the container when the lid is secured to the container in the manner described above. 
     Also, although it is preferred that the lid have only one latch element  42 , since it has been determined that a single latch member will provide adequate latching, it is contemplated that the lid may be formed with two such two latch elements for added safety, with the latch elements being disposed so that each is intercepted by one of the catches  70 . Preferably the two latch elements would be located diametrically opposite one another. Having two latch elements is desirable since both would have to be released simultaneously in order to permit the lid to be rotate to detaching position. Such an arrangement would make it more difficult for a child to remove the lid, thus achieving a higher degree of safety. 
     Preferably the container is intended for use as a bucket or pail. Accordingly, as an optional measure, each of the bulge portions  58  is formed with a hole  86  to accommodate an arched handle or bail, whereby the container can function as a pail or bucket. It also is contemplated that the container need not have handle portions  58  or a bail-type handle, but instead the container may have no handle or a different type of handle. Although the lid is illustrated at having a substantially flat crown, it is contemplated that it may be corrugated for added stiffness or for ornamental reasons, e.g., like the circular corrugations of the lid shown in U.S. Pat. No. 4,930,656 issued to H. J. Blanchette. 
     The foregoing modifications, and still other modifications rendered obvious to a person skilled in the art from the foregoing description and the drawings, may be made without departing from the spirit and scope of the present invention. 
     The advantages of the invention are several. For one thing the entire specific designs can be implemented by conventional injection molding techniques and apparatus, an important cost factor. For another thing, locking tabs and the openings therefor in the container assure easy and secure attachment of the lid to the container. Another advantage resides in the fact that the locking operation of latch element  42  on the lid vis-à-vis the catches on the container is reliable and automatic. When the lid is to be assembled to the pail, if the lid is rotated clockwise relative to the pail (as viewed in FIG.  4 ), latch member  42  will contact one of the catches  70  and due to its resiliency, as the lid continues rotation in the same direction, it will be forced inwardly toward the center axis of the container by the contacted catch  70 , whereby the latch member will “ride over” that particular catch. The angular face on each of the catches  70  facilitates the inward camming action on latch member  42  as the lid is rotated clockwise (as seen in FIG.  4 ). Due to its resiliency, latch member  42  will return automatically to its original outwardly projecting position (shown in  FIGS. 4 ,  5  and  7 ) when it has moved past the catch which caused it to be cammed inward. However, on counter-clockwise movement of the lid, that same catch will intercept the outwardly projecting end  44  of the latch member and thereby stop the lid from being turned to the angular position required to releases the locking tabs from the openings  62  or  62 A. Because of the inherent resiliency of the latch member, releasing the latch member from the interfering catch is accomplished by manually depressing the latch member inward while simultaneously rotating the lid counter-clockwise. Other advantages will be obvious to persons skilled in the art.