Cover, A Container Assembly Including The Cover, A Molding Device For Molding The Cover And A Method For Manufacturing The Cover

Abstract

A cover for covering an opening of a container for a food stuff includes a substantially flat cover body including at least one aperture and at least one substantially flat flap. The at least one flap including a linear proximal end configured to connect with the cover body and allow the at least one flap to rotate with respect to the cover body. A lower surface of the at least one flap includes a protrusion configured to close the at least one aperture when the at least one flap is at a first position in which the at least one flap is in parallel with the cover body. The cover body and the at least one flap are integrally formed by a co-injection molding. The container and cover are suitable for heating a food stuff in a microwave.

Claims

1. A cover for covering an opening of a container for heating a food stuff, the cover comprising: an elevated peripheral portion defining an outer contour of the cover and configured to engage with an edge of the container defining its opening; an elevated area surrounded by and positioned apart from the elevated peripheral portion, the elevated area being lower than the peripheral portion; a plurality of air vent ports defined in the elevated area; at least one flap including a proximal end integrally connected to an edge of the elevated area, the at least one flap configured to rotate around the proximal end; at least one protrusion extending from a first surface of the at least one flap and configured to plug at least one of the plurality of air vent ports when the flap reaches a first position where the at least one flap is received in a concave area defined in the elevated area; and a groove defined at the proximal end in the first surface of the at least one flap wherein a second surface opposite to the first surface at the proximal end is straight when the flap stands upright to the concave area.

2. The cover in claim 1, wherein the second surface of the at least one flap does not protrude from a surface of the elevated area when the at least one flap reaches the first position.

3. The cover in claim 1, wherein the cover is not deformed under a thermal condition less than 140 degrees centigrade.

4. The cover in claim 1, wherein the cover is molded from a high crystallinity polypropylene.

5. The cover in claim 1 further comprising a tab protruding outwardly from a peripheral edge of the cover.

6. The cover in claim 1, wherein the proximal end of the at least one flap is located farther away from a center of the cover than a distal end of the flap.

7. The cover in claim 1, wherein: the elevated area includes a concave portion adjacent to the concave area; and a distal end of the flap partly covers across the concave portion when the at least one flap reaches the first position.

8. The cover in claim 1, further comprising an intermediate area connecting the elevated peripheral portion and the elevated area, the intermediate area being lower than the elevated area and surrounding the elevated area.

9. The cover in claim 1, wherein the at least one flap is configured to rotate upwardly from the first position responsive to an inner pressure of the container exceeding a predetermined pressure when the cover is installed on the container.

10. The cover in claim 9, wherein the predetermined pressure is determined by a friction force between the at least one protrusion and the at least one of the plurality of air vent ports.

11. A container assembly for heating a food stuff comprising a container including a bottom and at least one side wall surrounding the bottom, and a cover for covering an opening of the container comprising: an elevated peripheral portion defining an outer contour of the cover and configured to engage with an edge of the container defining its opening; an elevated area surrounded by and positioned apart from the elevated peripheral portion, the elevated area being lower than the peripheral portion; a plurality of air vent ports defined in the elevated area of the cover; at least one flap including a proximal end integrally connected to an edge of the elevated area, the at least one flap configured to rotate around the proximal end; at least one protrusion extending from a first surface of the at least one flap and configured to plug at least one of the plurality of air vent ports when the flap reaches a first position where the at least one flap is received in a concave area defined in the elevated area; and a groove defined at the proximal end in the first surface of the at least one flap wherein a second surface opposite to the first surface at the proximal end is straight when the flap stands upright to the concave area.

12. The container assembly in claim 11, wherein the second surface of the at least one flap does not protrude from a surface of the elevated area when the at least one flap reaches the first position.

13. The container assembly in claim 11, wherein the cover is not deformed under a thermal condition less than 140 degrees centigrade.

14. The container assembly in claim 11, wherein the cover is molded from a high crystallinity polypropylene.

15. The container assembly in claim 11, further comprising a tab protruding outwardly from a peripheral edge of the cover.

16. The container assembly in claim 11, wherein the proximal end of the at least one flap is located farther away from a center of the cover than a distal end of the flap.

17. The container assembly in claim 11, wherein: the elevated area includes a concave portion adjacent to the concave area; and a distal end of the at least one flap partly covers across the concave portion when the at least one flap reaches the first position.

18. The container assembly in claim 11, wherein the cover includes an intermediate area connecting the elevated peripheral portion and the elevated area, the intermediate area being lower than the elevated area and surrounding the elevated area.

19. The container assembly in claim 11, wherein the at least one flap is configured to rotate upwardly from the first position when an inner pressure of the container assembly exceeds a predetermined pressure.

20. The container assembly in claim 19, wherein the predetermined pressure is determined by a friction force between the at least one protrusion and the at least one of the plurality of air vent ports.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Hereinafter, the preferred embodiments of a cover and a container using thereof according to the present invention are explained by referring to drawings.

[0058] FIG. 1 is an exploded perspective view showing the container assembly of the present invention.

[0059] FIG. 2 is a plane view of the cover the container of the present invention.

[0060] FIG. 3 is an enlarged cross-sectional view around the flap of the cover shown in FIG. 2.

[0061] FIG. 4 is a further enlarged view to show of the proximal end configuration of the cover shown in FIG. 2.

[0062] FIG. 5 is a cross-sectional view of the cover shown in FIG. 2.

[0063] FIG. 6 is a schematic cross-sectional view of the resin-molding mold for the cover shown in FIG. 2.

[0064] FIG. 7 is an enlarged view to show detail configuration of the mold in FIG. 6.

[0065] FIG. 8 is an exploded perspective view showing another embodiment of the cover of the present invention.

[0066] FIG. 9 is an exploded perspective view showing another embodiment of the container of the present invention.

[0067] FIG. 10 is a plain view showing another embodiment of the cover used for the container of the present invention.

[0068] FIG. 11 shows another embodiment of the container of the present invention.

[0069] FIG. 12 is an exploded perspective view showing another embodiment of the container of the present invention.

[0070] FIG. 13 is a cross-sectional view showing the stacked container of the present invention.

[0071] FIG. 14 is a perspective view of the conventional container assembly.

[0072] FIG. 15 is a cross-sectional view of the conventional container assembly.

[0073] FIG. 16 is a perspective view of the conventional container assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0074] FIG. 1 is an exploded perspective view of the container assembly of the present invention. FIG. 2 is a plain view of the cover of the present invention.

[0075] A container assembly (1) comprises a cover (2) and a container (3). The container (3) has a substantially rectangular cylindrical shape shown in FIG. 1 but not limited to this. It may also have a cylindrical/oval cylindrical shape comprising a bottom, or a triangular cylinder or other polygonal shape. The container (3) contains a desired food stuff. A couple of ears (31) extending from peripheral edges of the container (3) in parallel to each other are configured to facilitate carriage/handling of the container assembly (1).

[0076] The cover (2) is configured to have a shape and a size for covering a top opening of the container (3), and an example in FIG. 1 and FIG. 2 shows a substantially rectangular cover (2) similar to a contour of the container (3).

[0077] A cover (2) includes a cover body (21) and a flap (22). The cover body (21) comprises a peripheral area (211) defining an outer peripheral contour of the cover, a flap surrounding area (212) at least surrounding the flap (22) and an intermediate area (213) therebetween configured to connect these areas (211, 212). In FIG. 1 and FIG. 2, the flap surrounding area (212) is provided at a center of the cover body (21), but it may be also adjacently provided to the peripheral area (211).

[0078] In the example in FIG. 1 and FIG. 2, the peripheral area (211) and the flap surrounding area (212) may be elevated upwardly with respect to the intermediate area (213). Further, the peripheral area (211) may be higher than the flap surrounding area (212). In addition, a tab (214) protruding outwardly from a peripheral area (211) is formed in a substantially semicircle shape configured to facilitate detachable engagement with the container (3).

[0079] The flap (22) is a substantially semi-oval thin plate comprising a linear proximal end (221). The linear proximal end (221) of the flap (22) connects with the periphery of the flap surrounding area (212). The flap (22) rotates upwardly and downwardly around the proximal end (221).

[0080] A protrusion (222) is formed in a bottom of the flap and an aperture (121) is defined in the flap surrounding area (212). After the flap (22) rotates downwardly until the flap (22) is in parallel with a top surface of the flap surrounding area (212), the protrusion (222) closes the aperture (121).

[0081] FIG. 3 is a cross-sectional view showing a configuration of the cover (2) around the flap (22). FIG. 3(a) is a cross-sectional view of the flap (22) standing uprightly with respect to the cover body (21) after rotating the flap (22) upwardly. FIG. 3(b) is a cross-sectional view of the flap (22) in parallel with the top surface of the cover body (21) by a downwardly flap rotation.

[0082] The flap surrounding area (212) includes a downward concave area (122) and a deeper concave portion (123) adjacently provided thereto. When the flap (22) is downwardly rotated and a top surface of the flap (22) is in parallel with the top surface the cover body (21), a curved distal portion (224) of the flap (22) partly covers over the concave portion (123) so that it laterally extends an upper portion of the concave portion (123). The rest of the flap portion (22) other than the distal portion lies in the concave area (122).

[0083] The aperture (121) is formed in the concave area (122). When the flap (22) is downwardly rotated until the top surface of the flap (22) is in parallel with the top surface of the cover body (21), a projection ring (223) formed surrounding a periphery of the protrusion (222) engages with a bottom surface of the cover (2) so that a leveled position of the flap top surface with respect to the top surface of the flap surrounding area (212) surrounding the concave area (122) is fixedly kept.

[0084] A user may insert his/her finger into the concave portion (123) defined in the flap surrounding area (212) for accessing the flap bottom (22) in order to rotate upwardly. In addition, when the protrusion (222) plugs the aperture (121), the top surface of the flap does not protrude over the top surface of the flap surrounding area (212). Therefore, another container can be easily stacked on the container assembly (1), for example, in the refrigerator.

[0085] FIG. 4 is an enlarged cross-sectional view of the proximal end (221) of the flap (22). At the proximal end (221) of the flap (22), a groove (226) with an arc cross section is defined in a flap bottom (225) (referred herein to a lower surface of the flap (22) after its downward rotation). The groove (226) appears when the flap (22) stands uprightly to the cover (2) while a flat upper surface (227) of the flap appears behind the groove (226). The groove (226) facilitates the flap rotation while the flap top (227) at the upright position prevents further upward rotation of the flap (22) so that a rotation range is controlled between 0 degree (the flap (22) lies on the cover (2)) and 90 degrees (the flap (22) uprightly stands to the cover (2)).

[0086] When the flap (22) is downwardly rotated, the proximal end (221) of the flap (22) is bent around a deepest bottom line (261) of the groove (226).

[0087] FIG. 5 is a cross-sectional view of the cover (2). The peripheral area (211) defining the outer contour of the cover (2) surrounds and upwardly protrudes to the intermediate area (213). An upper edge of the peripheral area (211) is provided above the top surface of the flap surrounding area (212).

[0088] As shown in FIG. 5, the peripheral area (211) is formed to have a substantially U-shaped cross section so as to engage with an upper edge of the container (3).

[0089] FIG. 6 shows a shape of a cavity of a molding device for molding the cover (2).

[0090] The molding device comprises a fixed mold (41) and a moveable mold (42) configured to form a first cavity (45) therebetween for molding the cover body (21) of the cover (2). The fixed mold also includes a second cavity (46) for molding the flap (22). The second cavity (46) communicates with the first cavity between the fixed mold (41) and the moveable mold (42). Further, an injection portion (43) for injecting a molten-resin is provided with the fixed mold (41).

[0091] As clearly shown in FIG. 6, the second cavity (46) is configured to stand at a right angle with respect to the first cavity (45). The cavities (45, 46) make it possible to integrally mold the flap (22) and the cover body (21) with a co-injection molding as the molten resin surely flows into the second cavity (46) for molding the flap (22) through the first cavity (45).

[0092] FIG. 7 shows a configuration of the molding device shown in FIG. 6 around the second cavity (46) for a flap (22), wherein the molding device is in an open position after a molten-resin injection.

[0093] The fixed mold (41) comprises a lateral sliding block (411) including a molding surface configured to mold flap surface including a protrusion. A slope surface is opposite to the molding surface of the lateral sliding block (411), which is biased toward a protruding direction of the protrusion (222) by a biasing means such as a spring (not shown).

[0094] The fixed mold (41) further comprises a vertical sliding block (412) adjacent to a slope surface of the lateral sliding block (411). The vertical sliding block (412) includes a substantially right trapezium cross section. A slope surface of the vertical sliding block (412) is complementary to and adjacent to the slope surface of the lateral sliding block (411). An actuator (not shown) such as a cylinder connects to the vertical sliding block (412) to move upwardly and downwardly.

[0095] During molding the cover (2), the vertical sliding block (412) is at a lower limit position where a bottom of the vertical sliding block (412) to a top of the protrusion (421) upwardly protruding from a cavity surface of the moveable mold (42) to penetrate the first cavity (45). The protrusion (421) defines the aperture (121) of the cover (2).

[0096] The vertical sliding block (412) moves upwardly in an opening operation of the molding device. The lateral sliding block (411) is biased to the slope surface of the vertical sliding block (412) by the biasing means so that a vertical movement of the vertical sliding block (412) causes a lateral movement of the lateral sliding block (411) (in a protruding direction of the protrusion(222)) to be separated from the molded flap (22). Thus, the protrusion (222) of the molded flap (22) is completely separated from the lateral sliding block (411). Then, the moveable mold (42) is moved downwardly so that the molded cover (2) is removed from the fixed mold without any interference with the protrusion (222) of the flap (22).

[0097] The type of the molten resin injected from the injection portion (43) is not limited but it is preferable to have a heat resistance high enough for the cover (2) not to deform under a thermal condition less than 140 degrees centigrade, because the container assembly (1) of the present invention may be used in a cooking device such as a microwave. A high crystallinity polypropylene may be a preferable material, for example. Even after an endurance test in which the flap (22) of the cover (1) molded from the high crystallinity polypropylene was repeatedly rotated between an open position and a closed position (more than 3,000 times of repeated rotation of the flap (22)), the flap (22) did not break out.

[0098] FIG. 8 is a perspective view of a modified embodiment from the container assembly (1) in FIG. 1 to FIG. 6.

[0099] The container assembly (1) in FIG. 8 is formed with a plurality of the protrusions (222) (3 protrusions in FIG. 8) with the flap (22). The cover body (21) is also formed with the plurality of apertures (121) corresponding to the protrusions (222). When the flap (22) is rotated downwardly, the protrusions (222) engage with the corresponding apertures (121), respectively. Therefore, apertures (121) are capable of exhausting a larger volume of inflating gas in the container assembly (1) in heating.

[0100] FIG. 9 is a perspective view of another modified embodiment from the container assembly (1) in FIG. 1 to FIG. 6.

[0101] The container assembly (1) in FIG. 9 comprises a plurality of the flaps (22) (2 flaps in FIG. 9). Each flap (22) configured to face each other extends toward the center of the flap surrounding area (212). The flap surrounding area (212) is formed with the concave areas (122) and the concave portions (123) provided for each flap (22). Each flap (22) comprises the protrusion (222) and the concave area (122) is formed with the aperture (121) engaging with the protrusion (222). The configuration of the concave area (122), the concave portion (123), the protrusion (222) and the aperture (121) are the same as what is explained relating to the FIG. 1 to FIG. 6.

[0102] The container (3) includes a partition (32) configured to divide an inner space of the container into at least two compartments (33, 34). The apertures (121) are in fluid communication with the compartments, respectively when the cover (2) is attached to the container (3).

[0103] Generally, a volume of water vapor depends on a type of a food stuff to be heated. Thus, a concentration of the water vapor in the spaces (33, 34) of the container (3) may be different from each other during a heating process if every space (33, 34) contains a different food stuff, which leads to an inner pressure difference between the inner spaces (33, 34).

[0104] For example, if just one aperture (121) is provided on a cover (2) (like the container assembly (1) described in context with FIG. 1 to FIG. 6), the aperture (121) may communicate with either of the spaces (33, 34). In a closed space, with which the aperture (121) does not communicate, an inner pressure will rapidly and extremely go up as a temperature elevation compared with that in an open space with which the aperture (121) communicates, which may result in blowing of the cover from container (3).

[0105] As shown in FIG. 9, the container (3) having a plurality of the apertures (121) in fluid communication with each space (33, 34) and a plurality of the flaps (22) including the protrusions (222) which close the apertures (121) prevents the cover (2) from being blown off because the inflating gas can be surely exhausted from each space (33, 34).

[0106] FIG. 10 is a plain view of the modified embodiment from the cover (2) shown in FIG. 1 to FIG. 6.

[0107] The flap (22) of the cover (2) shown in FIG. 10 is adjacently provided in the peripheral area (211) of the cover body (21). The flap (22) is surrounded by the flap surrounding area (212).

[0108] The flap surrounding area (212) in FIG. 10 is a substantially rectangular shape of which one of corners is adjacent to one of corners of the substantially rectangular peripheral area (211). A couple of the edges of the flap surrounding area (212) defining its corner adjacent to a corner of the peripheral area (211) is coincident with the border of the peripheral area (211).

[0109] The aperture (121) is defined around the corner of the flap surrounding area (212) adjacent to the corner of the peripheral area (211). The flaps (22) are also provided with the protrusions (222) closing the aperture (121).

[0110] The proximal end (221) of the flap (22) is located more inwardly to the center of the cover than its distal end. The peripheral area (211) and the flap surrounding area (212) are elevated with respect to the intermediate area (213) connecting these areas (211, 212). The distal end of the flap (22) protrudes to a valley formed with 2 adjacent slopes of the peripheral area (211) and the flap surrounding area (212). Thus, the embodiment in FIG. 10 does not have the concave portion (123) in the cover (2) as shown in FIG. 1 to FIG. 6, but only the concave area (122) receiving the flap (22).

[0111] Therefore, the container assembly (1) can discharge the liquid (water) generated from the food stuff therein through the aperture (121) defined at the corner of the cover (2).

[0112] FIG. 11 shows a modified embodiment from the cover (2) in FIG. 10. FIG. 11(a) is a plain view of the cover (2) and the FIG. 11(b) is a cross-sectional view of the container assembly (1) to which the cover (2) in FIG. 11(a) is attached.

[0113] The cover (2) in FIG. 11 is formed in a cylindrical shape comprising a top and the aperture (121) is formed in a vicinity of the periphery of the cover (2). The cover (2) includes the flap (22) of which the distal end outwardly extends from the outer edge of the cover body (21). The flap (22) includes the protrusion (222) which closes the aperture (121) when the flap (22) is downwardly rotated.

[0114] An inner surface of the cover (2) and an upper outer surface of the container (3) are threaded.

[0115] The container assembly (1) in FIG. 11 is, for example, suitably used for cooking noodles such as pasta through the following steps: [0116] a) put the dried pasta in the container (3) then pour hot water; b) cover the container with cover (2) and rotate the flap (22) upwardly; [0117] c) put the container assembly (1) in the microwave and boil the pasta in the container assembly (1); and [0118] d) after the pasta is boiled, remove the container assembly from the microwave and discharge the hot water in the container assembly (1).

[0119] Consequently, only the boiled pasta remains in the container assembly (1).

[0120] Thus, the container assembly (1) of the present invention may be used for boiling the food stuff easily.

[0121] Further, friction force between the protrusion (222) and the aperture (121) or their sizes may be designed so that the flap (22) upwardly rotates when the inner pressure of the container assembly (1) exceeds a predetermined pressure. In this case, the container assembly (1) of which the aperture (121) is pluged with the protrusion (222) of the flap (22) lying on the top of the container (21) can be put in the microwave. For example, when the container assembly (1) containing a grain such as a potato is microwaved with closing the aperture (121), the potato can be boiled under a high pressure in the container assembly (1) so that the boiling time can be saved. In addition, when the pressure in the container assembly (1) exceeds the predetermined value, the flap (22) rotates upwardly so that the container assembly (1) will not burst.

[0122] A fixing method of the cover (2) with the container (3) is not particularly limited. The cover (2) formed in a cylindrical shape having a threaded outer surface may be engaged with the container (3) having a threaded upper inner surface.

[0123] Alternatively, as shown in FIG. 12, an ear (29) configured to rotate upwardly and downwardly may be attached to the periphery of the cover (2), and the outer surface of the container (3) can be provided with a ridge (39) configured to engage with an aperture (291) defined in a center of the ear (29). Thus, the ear (29) and the protrusion (39) are mechanically engaged.

[0124] FIG. 13 is a cross-sectional view showing the container assembly (1) described in context with FIG. 1 to FIG. 6 in a stacking package.

[0125] The bottom of the container (3) comprises a peripheral area (35) defining the contour thereof and a central area (36) surrounded by the peripheral area (35). The central area (36) curves upwardly.

[0126] As described above, the peripheral area (211) of the cover (2) and the flap surrounding area (212) in the center of the cover (2) are elevated with respect to the intermediate area (213) connecting these areas (211, 212).

[0127] When one container assembly (1) is placed on another container assembly (1), the flap surrounding area of the cover (2) is received in the central area (36) of the bottom of the container (3). Also, the peripheral area (35) of the bottom of the container (3) contacts with the intermediate area (213) between the flap surrounding area (212) and the peripheral area (211).

[0128] Thus, stable stacking of the container assemblies (1) can be achieved.

[0129] The present invention can be used as a container used with a cooking device for household use such as a microwave.