INTERLOCKING CONTAINER OR CUP

Abstract: The invention concerns thermoplastics material cups which nest to seal a chamber in the bottom of the lower cup. A thermoplastics material cup (12) for nesting in a like cup has an endless groove (28) on its interior wall spaced from the bottom (16) to interlock with a lug (36) adjacent the bottom (16) of a similar cup. The groove (28) and lug (36) have similarly sloped entry ramps (30, 38) leading to preferably vertical sealing sur­ faces (32, 40) and the lug (36) is about 10% larger than the groove (28) the dimensions being such that interengagement of the entry ramps (30, 38) causes longtitudinal compression of the lug (36) and consequential radial expansion giving inti­ mate sealing between the sealing surfaces (32, 40) to seal the space (60) in the bottom of the lower cup, so as to keep fresh a comestible located therein.

Description: INTERLOCKING CONTAINER OR CUP This invention relates to foamed thermoplastic containers and cups capable of being nested one into the other to protect comestible stored in the containers and cups from the atmosphere. There is a growing demand for vending machines which dispense both hot and cold beverages made from fresh ingredients. Different approaches have been taken to protect the ingredients in the dispenser. One approach is the storage of bulk concentrate for discharge into a cup to which water is subsequently added. The drawbacks with this approach are, the constant atmospheric contact with the concentrate, with consequent increase of moistness and loss of flavour, and the variance of the amount of concentrate discharged into each cup. A different and newer approach has been to provide stacks of beverage concentrate containing plastic cups stored for dispensing by vending machines, each cup containing a premeasured amount of beverage concentrate. The wedging of the upper cup into the lower cup is supposedto protect the comestible from the atmosphere. However, that is not the case. In an attempt to protect the comestible from the atmosphere, attempts have been made to seal the space between the cups. One approach is that shown in U.S. Patent 4,156,483 which discloses a stack of expanded or foamed polystyrene vending cups each having a wall thickness typically in the range of 1.0 to 3.0 mm, containing a comestible between adjacent cups. To seal the comestible, the patent teaches that each cup provides a lug on the outer surface of the cup at the bottom, and a groove having an entry ramp on the inside of the cup terminating at a radially extending upwardly facing sealing ledge or surface. In use, an upper cup is pushed into a lower cup so that when the lug enters the groove, the entry ramp allegedly engages the upper surface of the lug and forces the bottom of the lug to seat on the ledge to seal the space between the cups. In other words, the entry ramp of the groove is supposed to push against the sloped upper portion of the lug to cause the bottom of the lug to seal against the upper surface of the ledge when the lug is in the groove and seats on the ledge. The difficulty with this approach is the material which the U.S. Specification 4156483 is working with. The expansion of the polystyrene beads is uneven. Additionally, the fused and expanded material is subject to cracking and chipping when overly stressed. Where the polystyrene foam is to be compressed to permit entry of the lug into the groove as proposed by Day, it must not only not be compressed beyond its-"memory." so that it will be able to restore to its original shape tot fit into the groove and provide the seal, but also it must not contain sharp corners, otherwise they will break off when compressed and not seal satisfactorily. If the lug is smaller than the groove it is readily apparent that the lug and ledge will not seal. If the lug is larger than the groove, because of the structure of the lug, groove and sealing ledge, the lug will not enter the groove and seat on the ledge to create the seal. Because of the structural characteristics of polystyrene foam material, it is presently impossible to consistently manufacture equally sized lugs and matching grooves - however, even if possible to consistently manufacture the same size lug and groove, it is impossible to have the same sized lug enter the same sized groove as proposed by Day without precompressing at least one of the lug, groove wall or sealing ledge. In part, this is because the lug cannot engage the sloped upper surface of the groove, while at the same time cause the bottom of the lug to seat on the ledge to create the seal without the top of the ledge being required to flex downwardly and restore fully and completely to its original position as the lug enters the groove. Therefore, while the upper and lower cups will lock, a seal cannot be assured. The result is that Day's proposals for sealing a space between the cups cannot assure a seal causing comestible in the cups to loose its freshness. It is therefore, an object of this invention to provide foamed thermoplastic containers and cups capable of stacking with other containers and cups and seal the space between the adjacent containers and cups, respectively, to protect comestibles or beverage concentrates at the bottom of the container or cup, and which containers and cups are also easily dispensed from a dispenser. Recognising the above described deficiencies found in the prior art expanded polystyrene foam cups, this invention provides resilient yieldable, nestable, tapered foamed thermoplastic (including expanded polystyrene) containers and cups, each container or cup, as the case may be, having an endless groove and endless lug, extending from the inside and outside surfaces of the container or cup wall, the groove penetrating the container or cup wall through either the inner or outer surface of the cup wall a predetermined distance from the bottom of the container or cup, the endless lug extending from the other surface of the cup wall for locking in the groove of a like container or cup when nested with the other container or cup, the endless lug being slightly larger in size and preferably about 10% larger (in volume) than the groove, and preferably conforming in shape to the groove, the groove comprising an entry and exit ramp, preferably at an angle of about 150 to the vertical, which ramp first engages the endless lug when like containers or cups are nested, and an intermediate sealing surface angled to the entry ramp, preferably oriented substantially vertically, the endless lug having an entry ramp to facilitate entry and exit of the lug into the groove, the entry ramp of the lug oriented preferably at the same angle as the entry ramp of the groove and a sealing surface extending from the entry ramp of the lug for forming a radial compression seal with the intermediate sealing surface of the groove and preferably a ramp on the opposed end of the lug extending towards the cup surface for facilitating entry of the lug into the groove, whereby when the lug is gradually compressed by the container or cup wall prior to entering the groove, the lug on entering the groove, facilitated by the entry and exit ramp, is compressed longtitudinally of the cup causing the lug to expand radially forcing the sealing surface of the lug into intimate contact with the intermediate sealing surface of the groove. If a ledge is provided under the groove or proximate bottom of the groove, the bottom of the lug does not seat on the ledge but is spaced therefrom to permit the radial expansion of the lug to cause the sealing of the sealing surfaces. Preferably the lug is about 10% larger than the groove. If much larger, the lug will not be accommodated by the groove and provide the seal. If much smaller, the lug will not form the requisite seal with the groove. However, the lug can be in the range 6 to 14% larger and preferably in the range 8 to 12% larger. According to one form of the invention, when the groove penetrates the outside surface of the container or cup wall, the endless lug extends inwardly from the inside surface of the cup wall and is of an inner diameter at its maximum width slightly less than the diameter of the groove at its maximum penetration into the container or cup wall Additionally, the entry and exit ramp of the groove is adjacent the bottom of the groove and that part of the groove wall extends upwardly and radially inwardly to the intermediate sealing surface of the groove and the entry ramp of the lug for engaging the entry and exit ramp of the groove is at the bottom of the lug and is preferably angled at about the same angle as the entry and exit ramp of the groove. According to another form of the invention, when the groove penetrates the inside surface of the container or cup wall, the endless lug extends outwardly from the outside surface of the container or cup wall and is of an outer diameter at its maximum width slightly greater than the diameter of the groove at its maximum penetration into the container or cup wall. Additionally, the entry and exit ramp is at the top of the groove and that part of the groove extends downwardly and radially outwardly to the intermediate sealing surface, and the entry ramp of the lug for engaging the entry and exit ramp of the groove is at the top of the lug and is preferably angled at about the same angle as the entry and exit ramp of the groove. According to another aspect of the invention, resilient, yieldable, nestable, tapered foamed thermoplastic (including expanded polystyrene) containers and cups are provided, each container or cup as the case may be, having an endless groove spaced from the bottom of the container or cup, extending radially outwardly from the inside wall of the container or cup, penetrating the container or cup wall, an endless lug extending around the outside surface of the container or cup respectively, at the bottom of the container or cup, the lug being slightly larger in size and preferably about 10% larger in size than the groove, and preferably conforming in shape to the groove, the groove comprising an entry and exit ramp, 0 preferably at an angle of about 15 to the vertical, which ramp first engages the endless lug when like containers or cups are nested, and an intermediate sealing surface angled to the entry and exit ramp preferably oriented substantially vertically, the endless lug having an entry ramp to facilitate entry and exit of the lug into and from the groove, the entry ramp of the lug oriented preferably at the same angle as the entry ramp of the groove and a sealing surface extending from the entry ramp of the lug for forming a radial compression seal with the intermediate sealing surface of the groove and preferably a ramp on the opposed end of the lug extending towards the cup surface, whereby when the lug is gradually compressed by the container or cup wall prior to entering the groove, the lug on entering the groove facilitated by the entry ramp is compressed longtitudinally of the cup length causing the lug to expand radially forcing the sealing surface of the lug into intimate contact with the intermediate sealing surface of the groove. According to preferred feature of the invention, the entry ramp of the lug is at least about 10% greater in length than the entry ramp of the groove. Preferably, when the containers or cups are nested, and the sealing surfaces radially compress together sealing the lug in the groove, the outer side wall of the inner container or cup is spaced from the inner wall of the outer container or cup. According to another feature of the inVention, a downwardly directed ledge may be provided on the outside wall of the container or cup, adjacent the mouth of the container or cup, for rigidity and which ledge preferably seats on the mouth rim of a lower container or cup, when the containers or cups are nested and the lug locked in the groove and the sealing surfaces radially compressed to seal the space therebetween. In one embodiment a ledge may be provided on the inside wall of the container or cup, below the groove or lug as the case may be, between the bottom of the container or cup as the case may be and the groove or lug preferably just below the lowest part of the groove or lug but not so as to interfere in any way with the lug or the formation of the compression seal between the intermediate sealing surface of the groove and sealing surface of the lug. Therefore, when two containers or cups are to be nested, the upper container or cup is pressed into the lower container or alp with the lug being slightly compressed by the inner tapered wall of the lower container or cup until it partially restores to its configuration as it enters the groove. As it enters the groove, the entry and exit ramp of the groove exerts a force on the lug (including the entry ramp of the lug) in a direction towards the bottom of the cup compressing the lug axially to provide the compression seal between the sealing surfaces. Because the lug is larger than the groove, the lug is not totally carried in the groove and is able to radially expand as it is compressed longtitudinally of the cup length to provide the seal between the sealing surfaces. At the same time, as the lug locks in the groove, and seals the space between the cups and the containers, the downwardly directed ledge (if employed), at the upper end of the cup or container preferably seats on the annular rim of the container or cup Embodiment of cups in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings of which: FIGURE 1 is a perspective view of a stack of cups nested one into the other according to a preferred embodiment of the invention. FIGURE 2 is a perspective view of a cup according to the preferred embodiment of the invention of Figure 1, with a portion cup away to show the cross-section of the cup wall and bottom. FIGURE 3 is a cross-section taken through two nested cups according to the preferred embodiment of the invention shown in Figure 2. FIGURE 4 is a close-up view of a portion of one of the cups shown in Figure 3 according to the preferred embodiment of the invention. FIGURES 5 to 7 inclusive, are cross-sectional close-up views of parts of two cups, each manufactured as shown in Figure 4, being nested together to seal the space therebetween. FIGURE 8 is a cross-sectional close-up view of parts of two cups nested according to another embodiment of the invention. FIGURE 9 is a cross-sectional close-up view of part of a cup according to still another embodiment of the invention. With reference to Figures 1 and 3, there is shown a stack of cups 10, each cup 12 (shown best in Figures 2 and 4) being made of resilient, yieldable, foamed theremoplastic polystyrene material and having a side wall 14, bottom 16, and upper flange 18 forming rim 20 defining mouth 22. On the underside of flange 18, is a thicker portion 24 for rigidity having downwardly directed shoulder or ledge 26. Extending outwardly from the inner wall of cup 12 and spaced a predetermined distance from the bottom is endless groove 28 defined by groove wall 29 seen best in Figure 4 having radially outwardly sloped entry ramp 30, sloped at 150 (in the range 120 to 180) to the vertical, and being .015 inches (.038 cms) long vertically oriented intermediate sealing surface 32, .048 inches (.122 cms) long, and radially inwardly directed lower portion 34 angled at 200 to the horizontal and being .014 inches (.036 cms) long. At the base of cup 12 forming an endless protuberance or lug extending from side wall 14 at the juncture with the bottom 16 is endless lug 36, having an upper entry ramp 38 being .017 inches (.043 cms) (.0002 inches (.005 cms) longer than entry ramp 30 of groove wall 29) and angled at the same angle as ramp 30, sealing surface 40 angled at the same angle as surface 32 and of the same length, and ramp 42, .015 inches (.038 cms) long angled in the same manner as portion 34 of groove wall 29. Therefore, as can be seen from the dimensions of lug 36 and groove 28, lug 36 is about 10% larger than groove 28. The about 10% larger cross-sectional area of the lug can be achieved by other dimensional changes rather than increasing the length of the lug ramps. The taper of the inner wall and outer wall of each cup 12 is 90 to the vertical. The bottom 16 of cup 12 has transverse or horizontal portion 44 spaced from the bottom lug 36, and angled portion 46 angled 150 (in the range 120 to 180) to the horizontal, connecting lug 36 to the horizontal portion 44. Each cup 12 has outer and inner diameters at its mouth of 2.915 inches (7.404 cms) and 2.780 inches (7.061 cms) respectively and outer and inner diameters at the bottom of 1.957 inches (4.971 cms) and 1.829 inches (4.646 cms) respectively. In use, a comestible is deposited in the botton of cup 12. As another cup is pressed into the lower cup to seal the ingredients, lug 36 is compressed by the inner side wall of the outer cup (see Figures 5 and 6) until the lug enters groove 28 (see Figure 6 showing the lug in its distorted configuration). As it enters groove 28, entry and exit ramp 30 axially compresses lug 36 longtitudinally of the cup, causing lug 36 to expand radially outwardly forcing surface 40 into intimate contact with the surface 32 for sealing the space 60 between the cups (see Figure 7). While in this embodiment, ramps 34 and 42 do not touch due to the distortion of the lug, in other embodiments, they may. As lug 36 enters groove 38, and sealed space 60, downwardly directed ledge 26 of the upper cup seats on rim 30 of the lower cup. With reference to Figure 8, each of the cups 12 has been modified to incorporate a horizontally extending inwardly directed ledge 62 spaced from the bottom of groove 28 (groove 28 of the same dimensions as previously indicated), ledge 62 for acting only as a scavenging ledge for supporting a scavenging disc for scavenging comestibles found above the level of the ledge after the filling cycle of the cup has been completed. At no time does lug 36 (of the same dimensions as previously indicated) engage ledge 62 when lug 36 is locked in groove 28 to create a seal between surfaces 32 and 40. With reference to Figure 9, part of cup 121 is shown having endless groove 281 defined by groove wall 291 extending inwardly from the outer surface of wall 141 adjacent bottom 161, lug 361 extending inwardly from the inner surface of cup wall 141. Each of groove 281 and lug 361 has a shape the reverse of the shape of groove 28 and lug 36 respectively. Particularly, entry and exit ramp 301 inwardly sloped at 150 to the vertical corresponds to equal length entry ramp 30, intermediate vertical sealing surface 321 to intermediate vertical sealing surface 321, and upper portion 34 angled at 200 to the horizontal corresponds to equal length lower portion 34. Similarly, lug 361 has corresponding lower equal length entry ramp 381 to entry ramp 38 of Figure 4, intermediate vertical sealing surface 401 to sealing surface 40, and upper portion 421 to portion 42. In use, an upper cup 121 is pressed into a lower cup compressing the lug or lug 361 on the inner surface of the outer cup until lug 361 enters groove 281 of the inner cup. As it does so, entry and exit ramp 301 axially compresses larger lug 361 longti- tudinally of the cup, causing lug 361 to expand radially inwardly and force surface 401 to seal with surface 321 for sealing the space between cups. As in the previous embodiment, the downwardly directed ledge (ledge 26 ) of the upper cup seats on the rim of the lower cup when lug 361 enters groove 281 and seals the space between the nest cups. For discharge from the stack of cups, the lowermost cup is easily moved away from the stack and particularly the cup thereabove, facilitated by entry and exit ramp 30 or 301 as the case may be.

Claims: CLAIMS 1. A resilient, yeildable, tapered, foamed, thermoplastics container or cup, nestable with like containers or cups, having an endless groove (28) and an endless lug (36), extending one from the inside surface and one from the outside surface of the container or cup wall, the groove penetrating the container or cup wall through either the inner or outer surface of the cup wall a predetermined distance from the bottom of the container or cup, the endless lug extending from the other surface of the cup wall for locking in the groove of a like container or cup when nested, the groove comprising a groove ramp (30), which ramp first engages the endless lug when like containers or cups are nested, and an intermediate sealing surface (32) angled to the ramp (30), the endless lug having a lug ramp (38) to facilitate entry and exit of the lug, into and from, the groove, and a sealing surface (40) extending from the ramp of the lug; characterised in that the lug (36) is slightly larger in size than the groove (28) and is dimensioned so that the sealing surface (40) of the lug forms a radial compression seal with the intermediate sealing surface (32) of the groove, the arrangement being such that when the lug is gradually compressed by the container or cup wall prior to entering the groove, the lug on entering the groove, facilitated by the groove ramp (30), is compressed longtitudinally of the cup length, causing the lug to expand radially forcing the sealing surface (40) of the lug into intimate contact with the intermediate sealing surface (28) of the groove. 2. The container or cup of Claim 1, characterised in that a further lug ramp (42) is provided on the opposed end of the lug, said further ramp extending to the cup surface from the sealing surface (40) to facilitate entry of the lug into the groove. 3 The container or cup of Claim 1 or Claim 2 characterised in that the lug (36) is 6% to 14% larger in size than the groove (28). 4. The container or cup of Claim 1 or Claim 2 characterised in that the lug 136) is 8% to 12% larger in size than the groove (28). 5. The container or cup of Claim 1 or Claim 2 characterised in that the lug is about 10% larger in size.than the groove. 6. The container or cup of any of Claims 1 to 5 characterised in that the entry lug ramp (38) is 8% to 12% larger than the groove ramp (30}. 7. The container or cup of any of Claims 1 to 5 characterised in that the lug ramp (38) is about 10% larger than the groove ramp (30). 8. The container or cup of any of Claims 1 to 7 characterised in that the groove-ramp (30) is angled between 120 and 180 to the vertical. 9. The container or cup of any of Claims 1 to 7 characterised in that the groove ramp (30) is angled about 150 to the vertical. 10. The container or cup of any of Claims 1 to 9 characterised in that the intermediate sealing surface (32) of the groove (28) and sealing surface (40) of the lug (36) are oriented to extend substantially vertically. 11. The container or cup of any of Claims 1 to 10 characterised in that the lug (36) conforms to the shape of the groove (28). 12. The container or cup of any of Claims 1 to 11 characterised in that the groove (281) penetrates the- outside surface of the container or cup wall, the endless lug (361) extends inwardly from the inside surface of the cup wall and is of aninner diameterat its maximum width slightly less than thediameterof the groove at is maximum penetration into the container or cup wall and the groove ramp (301) is adjacent the bottom of the groove and extends upwardly and radially inwardly to the intermediate sealing surface (321) of the groove and the lug ramp (381) is at the bottom of the lug for engaging the ramp (30 ) of the groove 13. The container or cup of any of Claims 1 to 11 characterised in that the groove (28) penetrates the inside surface of the container or cup wall, the endless lug (36) extends outwardly from the outside surface of the container or cup wall and is of an outer diameter at its maximum width slightly greater than the diameter of the groove at its maximum penetration into the container or cup wall and the groove ramp (30) is at the top of the groove and that part of the groove extends downwardly and radially outwardly to the intermediate sealing surface (32), and the ramp (38) of the lug is at the top of the lug for engaging the ramp (30) of the groove. 14. A resilient, yeildable, foamed, tapered, thermoplastics container or cup for nesting in a like cup having an endless groove spaced from the bottom of the container or cup, extending radially outwardly from the inside wall of the container or cup, penetrating the container or cup wall, an endless lug extending around the outside surface of the container or cup respectively, at the bottom of the container or cup, characterised in that the lug (36) is about 10% larger in size than the groove (28), the groove comprising an entry and exit ramp (30), at an angle of about 150 to the vertical, which ramp first engages the endless lug when like containers or cups are nested, and an intermediate sealing surface (32) angled to the entry and exit ramp oriented to extend substantially vertically, the endless lug having an entry ramp (38) at about the same angle as the entry ramp of the groove and a sealing surface (40) extending from the entry ramp of the lug for forming a radial compression seal with the intermediate sealing surface of the groove and a ramp on the opposed end of the lug, extending towards the cup surface, whereby when the lug is gradually compressed by the container or cup wall prior to entering the groove, the lug on entering the groove, facilitated by the entry and exit ramp, is axially compressed longtitudinally of the cup causing the lug to expand radially, forcing the intermediate sealing surface of the lug into intimate contact with the intermediate sealing surface of the groove. 15. The container or cup of Claim 14 characterised in that the entry ramp of the lug is about 10% larger than the entry and exit ramp (30) of the groove. 16. The container or cup of any of Claims 1 to 15, wherein the container or cup has an endless rim (18) surrounding its mouth and a downwardly directed ledge (26) thereunder for rigidifying the cup. 17. The container or cup of Claim 14 characterised in that the ledge (26) seats on the mouth rim (20) of a lower container or cup, when the containers or cups are nested and the lug locked in the groove sealing the space therebetween. 18 The container or cup of any of Claims 1 to 17 characterised in that an upwardly directed scavenging ledge (62) is provided on the inside wall of the container or cup spaced below the groove or lug as the case may be, but so as not to interfere with the locking of the lug into the groove and sealing of the sealing surfaces.

Inventors: ALGIS, AUGUST
Applicants: ROBOSERVE LIMITED
Application year: 1981
Main classification: B65D1
IPC codes: B65D85, B65D1, B65D81