Having described this invention in detail, what
I claim is
1. A disposable one-piece coverall, plastic lid comprising
2. A disposable one-piece coverall, plastic lid as described in claim 1 further characterized by
3. A disposable one-piece coverall, plastic lid as described in claim 1 further characterized by
4. In combination with the lid of claim 1,
5. In the combination of claim 4,
6. A disposable one-piece coverall, plastic lid as described in claim 1 further characterized by
7. In the combination of claim 4,
8. In the combination of claim 4,
9. In the combination of claim 5,
10. A disposable one-piece coverall, plastic lid as described in claim 1 further characterized by
This invention relates to plastic lids, and more particularly comprises a new and improved disposable one-piece coverall plastic lid such as those used with food containers filled on automatic filling machines.
At the present time it is common practice to use coverall lids made of plastic in combination with food containers filled on automatic filling equipment. The machines presently available to fill the containers and subsequently cap them include automatic lid-handling mechanisms which slice feed the lids in stack form one at a time to a capping station. In such mechanisms the lids are stacked in nested relationship, and stacking facilities are designed into the lids in an effort to avoid compacting of the lids, which makes them difficult to separate. Nevertheless, because the lids are often made of relatively thin plastic material, they are quite flexible and distort readily, and they frequently compact together during shipment or in the magazine of the lid-handling mechanism. When lids are in a compacted state while in the magazine, the feeding mechanism cannot separate the lids properly, and the mechanism jams and special attention is required of the operator. In certain prior art devices, special mechanisms such as revolving stack posts and motor-driven discs are built into the dispensers to create agitation in the stack. These mechanisms are expensive and are not altogether satisfactory.
One object of this invention is to provide a coverall lid capable of being handled in automatic lid-feeding mechanisms and which itself serves to agitate the lids in the magazine as each lid is fed so as to separate compacted lids and prevent additional compacting.
Another object of this invention is to provide a coverall lid which is suitable for use with so-called rim-stacking containers so as to establish a standard fill depth for the container when the bottom of the stacking facility is substantially above the normal fill height.
Another object of this invention is to provide means for enabling a single container to be used for different fill volumes.
FIG. 1 is a cross-sectional elevation view showing a lid and container constructed in accordance with this invention;
FIG. 2 is a cross-sectional view similar to FIG. 1 showing another container and lid constructed in accordance with this invention;
FIG. 3 is a fragmentary cross-sectional elevation showing a lid magazine and shuttle feed mechanism containing a stack of lids shown in FIG. 1;
FIG. 4 is a cross-sectional view similar to FIG. 3 and showing the manner in which the lowermost lid in the magazine is sliced from the stack and the effect of that action on other lids in the magazine;
FIG. 5 is a cross-sectional view similar to FIG. 4 and showing the mechanism filled with lids of the FIG. 2 embodiment;
FIG. 6 is a fragmentary cross-sectional view of two lids in nested relationship that comprise another embodiment of this invention;
FIG. 7 is a view of the lids shown in FIG. 6 compacted in jammed relation; and
FIG. 8 is a cross-sectional elevation view showing yet another embodiment of lid and container constructed in accordance with this invention.
In FIG. 1 a container 10 and lid 12 are shown with the lid seated on the container rim in sealed relationship. The container which may be of any configuration is shown in the drawing to include a bottom wall 14 and a sidewall 16 integrally joined at the lower corner 18. The upper portion 18 of the sidewall 16 of the container is provided with a lid seat 20 in the form of a shoulder which extends outwardly from the plane of sidewall 16. The upper margin of the sidewall 16 is provided with a rolled rim 22, and the container is designed to nest with other identical containers with the lower surface of shoulder 20 supported on the crown of the rim 22 of the next lower container, to prevent the containers from compacting, in accordance with well known techniques in the container art.
The lid 12 includes a closure wall 24 having a central portion 26 and a surrounding peripheral portion 28 joined by camming surface 20. Preferably the diameter of the central portion 26 of the lid exceeds the diameter of the bottom wall 14 of the container to form a seat when filled containers are stacked one on the other. The lid also contains a sidewall 32 joined to the peripheral portion 28 by bead 34 which is designed to cooperate with the lid seat 20 and/or inclined intermediate wall 35 of the upper portion 18 of the container to form a seal between the container and lid. As will be explained more fully below, the bead 34 also enhances nesting of identical lids of the type shown in a magazine, shipping carton, etc.
An outwardly extending flange 36 is connected to the top of sidewall 32 of the lid at corner 38, and a skirt 40 is joined to the outer edge 42 of the flange 36 and extends downwardly to the plane of the peripheral portion 28 of the closure wall 24. To seat the lid as shown in FIG. 1, the bead 34 is snapped by the inner edge 44 of the rim 22, and because the inner diameter of the rim 22 is less than the outer diameter of the bead 34, once in place it remains in place unless substantial force is applied to remove it.
It is to be understood that to effect a seal about the container mouth the peripheral portion 28 of the closure wall 24 of the lid need not be seated on the shoulder 20. The height of the sidewall 32 of the lid may be substantially shorter axially than the axial distance between the crown of the rim 22 and the shoulder 20, in which case the bead will not sit on the shoulder. The bead 34 normally should bear against the inclined wall 35 between the shoulder 20 and the rim 22, to effect the seal, which may or may not be supplemented by contact between shoulder 20 and peripheral portion 28.
When the lid is on the container, it will be noted that the central portion 26 extends substantially below the shoulder 20 so as to give the lid a depth d which is greater than the shoulder depth s. There are several desirable features which flow from this particular configuration. The food packaging industry has established a more or less standard lid depth which makes a most attractive package. That is, the cylindrical wall of the lid established by the rim-covering structure provides an esthetically pleasing appearance by giving the container the impression of strength and mass. However, with containers designed as rim stackers with lid seats very close to the top, less than the desired depth is provided if the closure wall of the lid is confined substantially to the plane of the lid seat shoulder 20. And it is desirable to reduce the axial extent between the rim crown and the lid seat 20 so as to reduce the stack height of a given number of containers when nested together, which obviously reduces shipping costs. Thus, the invention serves opposing interests by allowing the axial height between the rim and the lid seat 20 to be reduced while preserving the desired depth of the lid between the central portion 26 and the flange 36.
Another important advantage of this invention is illustrated in FIGS. 3 and 4. In those figures a magazine 50 is suggested composed of a number of spaced posts 52 secured together at their lower ends by plate 54 which in turn may be connected to the filling machine frame or other support. A typical magazine of the type shown is used on automatic filling equipment such as shown in copending application Ser. No. 607,251, filed Jan. 4, 1967 entitled LIQUID FILLING MACHINE. In that equipment containers are automatically filled, lids are fed automatically to the containers, and the lids are snapped in place. In the mechanism of FIG. 3 a shuttle 56 is movable back and forth below the magazine 50 on platform 58 to feed to the lids to a capping station (not shown). The lids 12 are stacked in the magazine 50 in the manner shown with the bottom of the sidewall 32 and the skirt 40 seated on the top of the sidewall and skirt of the next lower lid in the stack. In this arrangement a relatively stable stack is provided which tends to preserve the orderly arrangement of the lids in the magazine when stacked one upon the other as suggested. The bead 34 rests on flange 36 of the next lower lid to resist lid jamming.
With the shuttle 56 in the position illustrated, its recess 60 receives the lowermost lid in the magazine 50 so that the peripheral wall portion 28 rests on the surface 62 of support 58. A slot 64 may be provided in the support 58 to receive the camming surface 30 and the central portion 26 of the lowermost lid. To separate the lowermost lid from the stack, the shuttle 56 moves to the right, and this technique is ordinarily called slice feeding. When the lid is slice fed in this manner, it will be apparent that the corner 38 of the lowermost lid as viewed on the left in FIG. 3 will engage the camming surface 30' of the next upper lid 12' in the stack, and as the lowermost lid continues to move to the right it will elevate the stack of lids above it. This is clearly shown in FIG. 4. Thus, as each lid is sliced from the bottom of the stack during each actuation of the shuttle 56, the lowermost lid agitates the stack by pushing the lids upwardly in the magazine. This agitation serves to maintain the several lids in the stack in an uncompacted condition. That is, the lids have a tendency to jam together particularly when they are formed of thin sheet plastic material, and the agitation of the stack serves to unstick any of the lids which have become fully or partially jammed. The agitation will also serve to disturb the stack sufficiently to prevent the flange 36 of one lid from entering between the skirt and sidewall of the next upper lid. The stack is agitated during each cycle of the shuttle 56.
The camming surface 30 in each lid serves an additional function by providing axial stiffness in the closure wall 24 while enhancing radial flexibility. Thus it allows the bead 34 to snap more easily by the inner edge 44 of the rim.
The lid shown in FIG. 2 in one sense is the reverse of the lid of FIG. 1 in that its closure wall 70 has a central portion 72 that is displaced upwardly above the cylindrical wall 74 composed of the flange 76, sidewall 78, and skirt 80. The flange, sidewall and skirt of the lid of FIG. 2 may be identical to the corresponding parts of the lid of FIG. 1, as is the bead 82 which joins the sidewall 78 to the closure wall 70.
The container 10 illustrated in FIG. 2 is identical to that of FIG. 1, and it will be appreciated that with the lid of FIG. 2 the container volume is significantly increased. The extent of the increase is of course dependent upon the axial displacement of the central portion of the lid. It will be appreciated that significant savings may be realized by reducing inventory requirements if one size of container may be used for different volumes and only different lid configurations are used. Thus by providing a line of lids having central portions of different depth between the extremes of FIGS. 1 and 2, the same container could be used over a range of several ounces to pack ice cream or other foods.
In FIG. 5 the manner in which the lids of FIG. 2 may be slice fed from a magazine is suggested. When the lowermost lid is displaced to the right, the camming surface 86 of the lowermost lid on the right is shown to engage the camming surface 86' of the next upper lid so as to elevate that lid and as a result agitate all those lids above it in the magazine. Thus with each ejection of a lid from the magazine, the entire column of lids in the magazine is agitated to loosen them and prevent jamming. It will be appreciated if the closure wall 24 or 70 of either of the lids shown is confined to the axial space between the flange 36 or 76 and the bottoms of the skirt 40 or 80 and sidewall 32 or 78, no agitation will be imparted to the lids above the lowermost lid in the stack when the lowermost lid is slice fed by the shuttle but rather the column of lids will only fall in the magazine as each lid is sliced from the bottom.
In FIGS. 6 and 7 a slight modification of the invention is shown, and in connection with this embodiment the tendency of the lids to compact is illustrated. In FIG. 6, the lids 100 are provided with a beveled surface 102 which joins the sidewall 104 with the outwardly extending flange 106 at the cylindrical peripheral wall 108 that surrounds the closure wall 110. The beveled surface 102 serves as a support for the bead 112 at the bottom of the sidewall 104. It is evident in FIG. 6 that when the bead 112 of the upper lid rests on the beveled surface 102' of the next lower lid, and simultaneously the foot 114 of the skirt 116 engages the radius 118' of the next lower lid, the stack of lids has considerable lateral stability when nested in proper relationship with the lid axes coincident with one another. The beveled surface which adds to stack stability has the disadvantage of somewhat increasing the opportunity of the lids to compact. In FIG. 7 it will be noted that the bead 112 at the bottom of the sidewall 104 has moved down to engage the top of the sidewall 104' of the next lower lid, while the foot 114 at the bottom of skirt 116 has slipped down to engage the skirt 116' of the lower lid. Because the lids are often made of a very thin and flexible sheet material, the peripheral cylindrical structure of the lid can distort so as to bind on the lid below in the manner illustrated in FIG. 7. The inclined surface 102 may serve as a wedge to spread the gap between the skirt and sidewall to open it sufficiently to receive the peripheral structure of the next adjacent lid.
In connection with the embodiment of FIG. 1 mention was made of the advantage achieved by the lid of preserving the desired lid depth even when the stack height of the rim-stacking type of container is very small. This desirable feature may be served also by the embodiment of this invention shown in FIG. 8. In that figure the container 10 is identical to the container of FIGS. 1 and 2, but the manner in which the lid cooperates with the rim of the container to seal the container mouth is somewhat modified. Thus, the lid 120 includes a peripheral cylindrical structure 122 which surrounds the closure wall 124 in turn composed of the central portion 126, camming wall 128 and peripheral portion 130. In this form, the bead 132 which joins the peripheral portion 130 to the sidewall 134 engages the very bottom of the lid seat as defined by the shoulder 136 in the container, and the sidewall 134 extends upwardly an appreciable distance above the crown 138 of the container rim 140. The flange 142 thus spans the rim 140 spaced above the rim, and the skirt 144 of the lid extends downwardly from above the rim, to enclose it. By this arrangement, a standard or desired depth lid may be achieved. To gain the total desired lid depth, a part of that depth is made up by the extent of the sidewall 134 of the lid and the remainder by the depression in the closure wall 124. Significantly, the closure wall still contains the camming surface 128 to cause agitation of the lid as it is slice fed from the magazine. It will be appreciated that the lid may contain the inclined surface 102 as shown in the embodiment of FIG. 6, but that surface is not necessary.
While in the embodiments shown the skirt and sidewall of each lid are shown to be axially coextensive, it is to be understood that the lids need not have that configuration, and either the outer skirt or the sidewall alone may be used for nesting purposes. However, if the two are to cooperate as shown in FIG. 3 to support the lids in nested relation in the stack, then the axial height of the sidewall and skirt should be identical, but they need not be coextensive.