CONTAINER WITH CONCENTRIC SEGMENTED CAN BOTTOM

A container including a sidewall and an end panel is provided. The end panel includes a center panel, an elastic portion, and a frustoconical transition portion. The center panel and the elastic portion are configured to transition between a first configuration and a second configuration.

DETAILED DESCRIPTION

Referring generally to the figures, various embodiments of a container are provided. When some containers are filled with food and sealed, the can may be heated with the food inside to sterilize and/or cook the food. As the temperature inside of the sealed container increases, the pressure inside the sealed container increases. If the pressure outside of the container is too low relative to the interior pressure, stress may be placed on the container which can cause the container and/or the closure closing the container to deform, rupture, fail, and/or otherwise render the container unsuitable for use. Some systems place containers in environments of high external pressure while heating to balance the pressure inside of the container to prevent deformation, rupture, and/or failure of the container, however, doing so may be expensive and time consuming.

An embodiment of a container body is provided including an end panel. The end panel includes a feature configured to increase the volume of the container when the interior pressure of the container increases, thus decreasing the interior pressure, reducing stress placed on the rest of the container body, and eliminating the need to place the container in an environment of high external pressure. Additionally, embodiments of container bodies with end panels described herein may allow for use of thinner materials in making containers, as the increase in volume when interior pressure in the containers increases will subject the container materials to reduced stress. The feature is also configured to be returned to, e.g., be able to recover, its initial configuration, e.g., first state of equilibrium, decreasing the volume of the container body back to its initial volume upon cooling of the contents of the container body, returning the interior of the container body to its initial pressure, e.g., regaining the initial pressure inside the container upon sealing. Additionally, the feature is configured to transition between the initial configuration and the second configuration, e.g., second state of equilibrium, without deforming, e.g., irreversibly deforming, wrinkling, large-strain deformation, permanently deforming, etc., the end panel or the container body.

Referring toFIG. 1, a container body, shown as a can body20, is illustrated according to an exemplary embodiment. The can body20includes a sidewall22extending along a longitudinal axis from a first open end24to a second end closed by an end panel26. In one embodiment, the sidewall22and the end panel26are integrally formed.

In one embodiment, the sidewall22is a beaded sidewall. In another embodiment, the sidewall22is a straight, unbeaded sidewall. In another embodiment, sidewalls discussed herein may be shaped such that cross-sections taken perpendicular to the longitudinal axis of the container are generally circular. However, with reference toFIG. 16, in other embodiments the sidewall of can bodies, such as the can body illustrated therein, may be shaped in a variety of ways (e.g., having other non-polygonal cross-sections, as a rectangular prism, a polygonal prism, any number of irregular shapes, etc.) as may be desirable for different applications.

With reference toFIGS. 2 and 3, the end panel26includes a radially outer annular elastic portion28extending radially inwardly from the sidewall22to a frustoconical angular transition portion30. The transition portion30extends upwardly and radially inwardly from the elastic portion28to a circular center panel32.

With reference toFIGS. 4 and 5, the can body20has a height H1. The end panel26has a diameter D1. In one embodiment, the height H1is approximately 4.438 inches. In one embodiment, the diameter D1is approximately 2.88 inches. In the configuration illustrated inFIG. 5, the center panel32extends generally along a first plane P1. The elastic portion28extends generally along a second plane P2. The first plane P1and the second plane P2are generally parallel and non-coplanar. The center panel32is a height H2above the elastic portion28, e.g., the plane P1is a distance H2above the plane P2. In one embodiment, the height H2is approximately 0.12 inches. In one embodiment, the height H2is between approximately 1% and approximately 5% of the height H1of the can body20. In another embodiment, the height H2is between approximately 2% and approximately 3% of the height H1of the can body20. In another embodiment, the height H1is approximately 2.7% of the height H1of the can body20.

With further reference toFIG. 5, the transition portion30has an outer diameter D2. In one embodiment, the diameter D2is approximately 1.644 inches. In one embodiment, the diameter D2of the transition portion30is between approximately 40% and approximately 70% of the diameter D1of the end panel26. In another embodiment, the diameter D2of the transition portion30is between approximately 55% and approximately 60% of the diameter D1of the end panel26. In another embodiment, the diameter D2of the transition portion30is approximately 57% of the diameter D1of the end panel26.

As is illustrated inFIG. 5, the perimeter of the center panel32is generally defined by a bead50, e.g., raised portion, ridge, strengthening feature, etc. The center panel32has a diameter D3. In one embodiment, the diameter D3is approximately 0.75 inches. In one embodiment, the diameter D3of the center panel32is between approximately 10% and approximately 40% of the diameter D1of the end panel26. In another embodiment, the diameter D3of the center panel32is between approximately 20% and approximately 30% of the diameter of the end panel26. In another embodiment, the diameter D3of the center panel32is approximately 26% of the diameter of the end panel26.

In one embodiment, the diameter D3is between approximately 30% and approximately 60% of the outer diameter D2of the transition portion30. In another embodiment, the diameter D3is between approximately 40% and approximately 50% of the outer diameter D2of the transition portion30. In another embodiment, the diameter D3is approximately 46% of the outer diameter D2of the transition portion30.

With further reference toFIG. 5, the transition portion30extends at an angle θ1relative to the plane P2. In one embodiment, the angle θ1is between approximately 15° and approximately 25°. In another embodiment, the angle θ1is between approximately 17° and approximately 21°. In another embodiment, the angle θ1is approximately 19°.

In one embodiment, the elastic portion28includes a plurality of ridges34,36,38,40,42,44,46, and48, e.g., beads, strengthening features, elasticity-enhancing features, etc. In the illustrated embodiment, the elastic portion28includes eight ridges34,36,38,40,42,44,46, and48. The ridges34,36,38,40,42,44,46, and48are generally concentric with the sidewall22.

In one embodiment, the bead50extends a height H3upwardly from the plane P1. In one embodiment, the height H3is between approximately 0.01 inches and approximately 0.05 inches. In another embodiment, the height H3is between approximately 0.02 inches and approximately 0.03 inches. In another embodiment, the height H3is approximately 0.027 inches.

With reference toFIG. 6, in one embodiment, the elastic portion28includes eight ridges34,36,38,40,42,44,46, and48. The first, radially innermost ridge34is located a distance d1from the sidewall22. In one embodiment, the distance d1is between approximately 0.5 inches and approximately 0.6 inches. In another embodiment, the distance d1is approximately 0.57 inches. In one embodiment, the distance d1is between approximately 15% and 25% of the diameter D1(seeFIG. 5) of the end panel26. In another embodiment, the distance d1is approximately 20% of the diameter D1(seeFIG. 5) of the end panel26.

The second ridge36is located a distance d2from the sidewall22. In one embodiment, the distance d2is between approximately 0.45 inches and approximately 0.55 inches. In another embodiment, the distance d2is approximately 0.5 inches. In one embodiment, the distance d2is between approximately 15% and approximately 20% of the diameter D1(seeFIG. 5) of the end panel26. In another embodiment, the distance d2is approximately 17% of the diameter D1(seeFIG. 5) of the end panel26.

The third ridge38is located a distance d3from the sidewall22. In one embodiment, the distance d3is between approximately 0.4 inches and approximately 0.45 inches. In another embodiment, the distance d3is approximately 0.434 inches. In one embodiment, the distance d3is between approximately 12.5% and approximately 17.5% of the diameter D1(seeFIG. 5) of the end panel26. In another embodiment, the distance d3is approximately 15% of the diameter D1(seeFIG. 5) of the end panel26.

The fourth ridge40is located a distance d4from the sidewall22. In one embodiment, the distance d4is between approximately 0.325 inches and approximately 0.4 inches. In another embodiment, the distance d4is approximately 0.36 inches. In one embodiment, the distance d4is between approximately 10% and approximately 15% of the diameter D1(seeFIG. 5) of the end panel26. In another embodiment, the distance d4is approximately 12.5% of the diameter D1(seeFIG. 5) of the end panel26.

The fifth ridge42is located a distance d5from the sidewall22. In one embodiment, the distance d5is between approximately 0.275 inches and approximately 0.325 inches. In another embodiment, the distance d5is approximately 0.3 inches. In one embodiment, the distance d5is between approximately 7.5% and approximately 12.5% of the diameter D1(seeFIG. 5) of the end panel26. In another embodiment, the distance d5is approximately 10% of the diameter D1(seeFIG. 5) of the end panel26.

The sixth ridge44is located a distance d6from the sidewall22. In one embodiment, the distance d6is between approximately 0.2 inches and approximately 0.25 inches. In another embodiment, the distance d6is approximately 0.236 inches. In one embodiment, the distance d6is between approximately 5% and approximately 10% of the diameter D1(seeFIG. 5) of the end panel26. In another embodiment, the distance d6is approximately 8% of the diameter D1(seeFIG. 5) of the end panel26.

The seventh ridge46is located a distance d7from the sidewall22. In one embodiment, the distance d7is between approximately 0.1 inches and approximately 0.2 inches. In another embodiment, the distance d7is approximately 0.15 inches. In one embodiment, the distance d7is between approximately 2.5% and approximately 7.5% of the diameter D1(seeFIG. 5) of the end panel26. In another embodiment, the distance d7is approximately 5% of the diameter D1(seeFIG. 5) of the end panel26.

The eighth ridge48is located a distance d8from the sidewall22. In one embodiment, the distance d8is between approximately 0.25 inches and approximately 0.75 inches. In another embodiment, the distance d8is approximately 0.68 inches. In one embodiment, the distance d8is between approximately 1% and approximately 5% of the diameter D1(seeFIG. 5) of the end panel26. In another embodiment, the distance d8is approximately 2.4% of the diameter D1(seeFIG. 5) of the end panel26.

In other embodiments, the elastic portion28may include other suitable numbers of ridges.

With further reference toFIG. 6, the ridges34,36,38,40,42,44,46, and48have a height H4. In one embodiment, the height H4is between approximately 0.01 inches and approximately 0.05 inches. In another embodiment, the height H4is approximately 0.02 inches. In the illustrated embodiment, the ridges34,36,38,40,42,44,46, and48each have generally the same height. In other embodiments, the heights of the ridges may be nonuniform.

With reference toFIGS. 7 and 8, the can body20is filled through the open end24and the open end24is sealed, e.g., hermetically sealed, with a closure, in the illustrated embodiment, a can end52. The can end52is coupled to the sidewall22by a double seam54.

When the filled and sealed can body20is heated, e.g., to sterilize and/or cook the contents of the can body,20, because the can body20is sealed, e.g., hermetically sealed, by the can end52, interior pressure within the can body20increases, which exerts outwardly directed forces on the sidewall22, the end panel26, and the can end52.

In one embodiment, with the filled and sealed can body20under external ambient pressure, e.g., no overpressure applied, etc., the end panel26, including the elastic portion28, the transition portion30, and the center panel32, is configured such that the transition portion30and the center panel32will transition (e.g., snap-through, etc.) from the first configuration, e.g., first state of equilibrium, etc., illustrated inFIG. 8to a second configuration, e.g., second state of equilibrium, etc., illustrated inFIG. 9.

As is illustrated inFIG. 9, in the second configuration, the transition portion30extends at an angle θ2relative to the plane P2. In one embodiment, the angle θ1is between approximately 15° and approximately 25°. In another embodiment, the angle θ1is between approximately 17° and approximately 21°. In another embodiment, the angle θ1is approximately 19°.

In the second configuration illustrated inFIG. 9, the center panel32extends along a third plane P3. In one embodiment, the third plane P3is generally parallel to the second plane P2and the first plane P1. The third plane P3is non-coplanar with the second plane P2.

In one embodiment, the volume of the can body20in the second configuration is between approximately 0.1% and approximately 7% greater than the volume of the can body20in the first configuration. In another embodiment, the volume of the can body20in the second configuration is between approximately 0.2% and approximately 3% greater than the volume of the can body20in the first configuration. In another embodiment, the volume of the can body20in the second configuration is approximately 0.5% greater than the volume of the can body20in the first configuration. In another embodiment, the volume of the can body20in the second configuration is between approximately 4% and approximately 5% greater than the volume of the can body20in the first configuration. In one embodiment, the interior volume of the can body20is increased by 1 cubic inch when the center panel32and the transition portion30are in the second configuration (seeFIG. 9) relative to when the center panel32and the transition portion30are in the first configuration (seeFIG. 8).

In one embodiment, during heating, the contents of the can body22are heated to approximately 260° F. In one embodiment, the transition portion30and the center panel32will transition from the first configuration (FIG. 8) to the second configuration (FIG. 9) when the interior pressure inside of the can body22is between approximately 20 psig (pound-force per square inch gauge) and approximately 60 psig. In another embodiment, the transition portion30and the center panel32will transition from the first configuration (FIG. 8) to the second configuration (FIG. 9) when the interior pressure inside of the can body22is between approximately 35 psig and approximately 45 psig. In another embodiment, the transition portion30and the center panel32will transition from the first configuration (FIG. 8) to the second configuration (FIG. 9) when the interior pressure inside of the can body22is approximately 40 psig.

Once the heating process is completed, the sealed can body22is cooled, e.g., air cooled, cooled in water bath, etc. Similar to during heating, embodiments of the can body22with the end panel26may eliminate the need to cool (e.g., the initial stages of cooling, etc.) the sealed can body22in a pressurized environment, as the net outward force acting on the body and/or end walls of cans after the transition portion30and center panel32have transitioned to the second configuration is less than the burst strength (i.e., the force at which either the body or end walls of cans will fail, crack, rupture, permanently deform, etc.) of the can body22and can end52.

The end panel26including the transition portion30and the center panel32are configured to remain in the second configuration (FIG. 9) unless the transition portion30and the center panel32are subjected to a force or pressure, e.g., the transition portion30and the center panel32are configured to remain in the second configuration (FIG. 9) and not to return to the first configuration (FIG. 8) under ambient conditions unless a force or pressure is applied thereto, as described below.

After the contents of the sealed can body20have been sufficiently cooled, the sealed can body20has a lower interior temperature and pressure inside the sealed can body20, e.g., vacuum inside the sealed can body20, lower pressure inside the sealed can body20than when the can body20was sealed, etc.

In one embodiment, the end panel26is configured such that the center panel32and the transition portion30are configured to be maintained in the second configuration (FIG. 9), under normal ambient conditions, e.g., between approximately 40° F. and 100° F., between approximately 0.75 atmospheres of pressure and approximately 2 atmospheres of pressure, no increased external force being applied upwardly and/or inwardly to the end panel26, etc.

A force may be applied to the center panel32and/or the transition portion30in an upward, e.g., inward, direction, e.g., toward the can end52, toward plane P1, etc., to cause the transition portion30and the center panel32to transition from the second configuration (FIG. 9) back to the first configuration (FIG. 8). In one embodiment, this will decrease the volume of the interior of the sealed can body20and recover the initial pressure inside the sealed can body20, e.g., eliminate and/or reduce vacuum, increase pressure to initial pressure in sealed can body20immediately after sealing, gain positive pressure inside the sealed can body20, etc.

As with the transition from the first configuration to the second configuration, the elastic portion28, the transition portion30, and the center panel32are configured to avoid permanent deformation, wrinkling, etc., e.g., have elastic properties, be configured such that the elastic portion28, transition portion30, and center panel32, each are generally the same structurally and in appearance, before and after the transition portion30and the center panel32transition from the first configuration (FIG. 8) to the second configuration (FIG. 9) and back to the first configuration (FIG. 8).

When the center panel32and the transition portion30transition from the first configuration (FIG. 8) to the second configuration (FIG. 9) or from the second configuration (FIG. 9) to the first configuration (FIG. 8), the elastic portion28is temporarily deformed, e.g., flexes, etc., to allow the transition, but is configured to return to its original shape and structure, e.g., not wrinkle, not irreversibly deform, elastically deform, etc. The elastic portion28and the ridges34,36,38,40,42,44,46, and48are configured to provide the elastic portion28with elastic properties, e.g., the ability to resume normal shape spontaneously after distortion, the elastic portion28having generally the same shape, appearance, and configuration after the center panel32and the transition portion30have transitioned to the second configuration (FIG. 9) as when the center panel32and the transition portion30are in the first configuration (FIG. 8), e.g., the elastic portion28is not wrinkled, permanently deformed, etc., by the transition of the center panel and transition portion between the first configuration (FIG. 8) and the second configuration (FIG. 9).

Additionally, with reference toFIGS. 8 and 9, the center panel32and the bead50are configured to allow the center panel32to transition elastically and to provide the center panel32with elastic properties, e.g., the ability to recover normal shape spontaneously after distortion, the center panel32having generally the same shape and configuration after the center panel32and the transition portion30have transitioned to the second configuration (FIG. 9) as when the center panel32and the transition portion30are in the first configuration (FIG. 8), e.g., the center panel32is not wrinkled, permanently and/or irreversibly deformed, etc., by the transition of the center panel and transition portion between the first configuration (FIG. 8) and the second configuration (FIG. 9).

Additionally, with reference toFIGS. 8 and 9, the transition portion30is configured with elastic properties, e.g., the transition portion30is not wrinkled, permanently and/or irreversibly deformed, etc., by the transition of the transition portion30and the center panel32from the first configuration (FIG. 8) to the second configuration (FIG. 9) or by the transition back from the second (FIG. 9) configuration to the first configuration (FIG. 8).

In one embodiment, the force to transition the transition portion30and the center panel32from the second configuration (FIG. 9) to the first configuration (FIG. 8) may be applied by an actuator, such as a mechanical actuator, hydraulic actuator, electric actuator, etc., configured to apply a force, e.g., mechanical force, pressure, etc., to the center panel32and/or the transition portion30.

Embodiments of can bodies20may eliminate the need to heat cans in pressurized environments, e.g., eliminate the need for additional overpressure, when steam heated other than pressure from saturated steam, when heated by other methods, e.g., induction, other than ambient pressure, the pressure of the contents within the can at the maximum temperature does not rupture, break, fail, or permanently deform the body of the can within the heating chamber at atmospheric pressure, etc. Additionally, embodiments of can bodies20may eliminate the need to physically constrain cans from expanding due to heating, e.g., eliminate the need for physical support structures that may engage the can body (e.g., the end walls of the can to resist deformation).

Various methods to heat the contents of sealed cans are not dependent on an elevated pressure within a heating chamber, e.g., induction heating, etc. Embodiments of can bodies20with end panels26allow for heating of contents of the can bodies20without locating the can bodies20in a high pressure environment and without any damage, failure, permanent deformation, etc., to the can bodies20from the increased internal pressure due to the heated contents of the can bodies20.

Additionally, embodiments of can bodies20may eliminate the need to provide pressurized environments for cooling of cans (e.g., initial stages of cooling) eliminating the need for overpressure.

Additionally, in one embodiment, the configuration of the end panel26may allow a can body20, the end panel26, and the can end52to be formed from a thin material while still being able to withstand, e.g., not permanently deform, burst, etc., the pressure in the interior of the sealed can body20when the contents of the sealed can body20are heated. The can body20may be formed from a metal such as, e.g., aluminum, steel, other alloys, etc. With reference toFIG. 6, the end panel26has a thickness T1. In one embodiment, the thickness T1is between approximately 0.002 inches and approximately 0.01 inches. In another embodiment, the thickness T1is between approximately 0.005 inches and 0.009 inches. In another embodiment, the thickness T1is approximately 0.00715 inches.

With further reference toFIG. 6, the sidewall22has a thickness T2. In one embodiment, the thickness T2is between approximately 0.001 inches and approximately 0.005 inches. In another embodiment, the thickness T2is approximately 0.004 inches. In another embodiment, the thickness T2is approximately 0.003 inches. In another embodiment, the thickness T2is approximately 0.002 inches.

In one embodiment, the gauge of the material used to form the can end52may be reduced. In one embodiment, the gauge of steel used to form the can end52may be reduced from approximately 73 lbs. if an end panel not configured to transition to a second configuration is used to approximately 70 lbs. if the end panel26is used.

Having a sidewall22and an end panel26that may be formed from thinner material (e.g., less material) may provide for cost savings relative to a can body formed from thicker material.

In one embodiment, the can body20with the end panel26may be formed from metal that has been thinned prior to forming the features of the end panel26. Embodiments of can bodies20, e.g., can bodies with thin end panels and thin sidewalls, described herein may be formed using the apparatuses and methods described in U.S. patent application Ser. No. ______ entitled Container With Expanded Bottom and Method, filed on Mar. 14, 2013, which is incorporated herein by reference in its entirety. In another embodiment, the can body20may be formed from interstitial-free steel.

In one embodiment, end panel26is configured such that the transition portion30and the center panel21are configured to remain in the first configuration (FIG. 8) after transitioning from the second configuration (FIG. 9) back to the first configuration (FIG. 8) upon cooling of the contents of the sealed can body20under normal, ambient conditions, e.g., between approximately 32° F. and 100° F., between approximately 0.5 atmosphere and approximately 2 atmospheres, etc.

With reference toFIGS. 10 and 11, another embodiment of a can body120is provided. The can body120has many similarities to the can body20described above, therefore, differences between the can body120and the can body20are the focus of the description below.

The can body120includes a sidewall122extending from a first open end124to a second end. The second end is sealed, e.g., hermetically sealed, by a can end126coupled to the sidewall122. In one embodiment, the can end126is coupled to the sidewall122by a double seam. As is illustrated inFIGS. 10 and 11, the end panel126is not integrally formed with the sidewall122.

In one embodiment, a second end panel, similar to the end panel126may be coupled to the first end124of the sidewall122, e.g., by a double seam, etc., to seal, e.g., hermetically seal the first end124of the sidewall122. In this configuration, the center portions and transition portions of both the end panel126and the second end panel are configured to transition to a second configuration to increase the volume of the interior of the sealed can body120. In one embodiment, this configuration would provide additional, e.g., twice as much, increase in volume in the interior of the sealed can body120when the center portions and the transition portions of both end panels are in the second configuration.

With reference toFIGS. 12-15, another embodiment of a can body220is illustrated. The can body220has many similarities to the can bodies described above, therefore, differences between the can body220and the can bodies above are the focus of the description below.

The can body220includes an elastic portion228extending generally from the sidewall220to the angular transition portion230. The elastic portion228includes six ridges, e.g., beads, strengthening features, elasticity-enhancing features, etc. In the illustrated embodiment, the ridges234,236,238,240,242,244,246, and248are generally concentric with the sidewall222.

The first, radially inwardmost ridge234is located a distance d9from the sidewall222. In one embodiment, the distance d9is between approximately 0.55 inches and 0.6 inches. In another embodiment, the distance d9is approximately 0.57 inches. In one embodiment, the distance d9is between approximately 15% and approximately 25% of the diameter D1(seeFIG. 14) of the end panel226. In another embodiment, the distance d9is approximately 20% of the diameter D1(seeFIG. 14) of the end panel226.

The second ridge236, located radially outwardly from the first ridge234, is located a distance d10from the sidewall222. In one embodiment, the distance d10is between approximately 0.45 inches and approximately 0.55 inches. In another embodiment, the distance d10is approximately 0.5 inches. In one embodiment, the distance d10is between approximately 15% and approximately 20% of the diameter D1(seeFIG. 14) of the end panel226. In another embodiment, the distance d10is approximately 17% of the diameter D1(seeFIG. 14) of the end panel226.

The third ridge238, located radially outwardly from the second ridge236, is located a distance d11from the sidewall222. In one embodiment, the distance d11is between approximately 0.4 inches and approximately 0.45 inches. In another embodiment, the distance d11is approximately 0.434 inches. In one embodiment, the distance d11is between approximately 12.5% and approximately 17.5% of the diameter D1(seeFIG. 14) of the end panel222. In another embodiment, the distance d11is approximately 15% of the diameter D1(seeFIG. 14) of the end panel222.

The fourth ridge240, located radially outwardly from the third ridge238, is located a distance d12from the sidewall222. In one embodiment, the distance d12is between approximately 0.35 inches and approximately 0.4 inches from the sidewall222. In another embodiment, the distance d12is approximately 0.36 inches. In one embodiment, the distance d12is between approximately 10% and approximately 15% of the diameter D1(seeFIG. 14) of the end panel222. In another embodiment, the distance d12is approximately 12.5% of the diameter D1(seeFIG. 14) of the end panel222.

The fifth ridge242, located radially outwardly from the fourth ridge240, is located a distance d13from the sidewall222. In one embodiment, the distance d13is between approximately 0.25 inches and approximately 0.35 inches. In another embodiment, the distance d13is approximately 0.3 inches. In one embodiment, the distance d13is between approximately 7.5% and 12.5%. of the diameter D1(seeFIG. 14) of the end panel222. In another embodiment, the distance d13is approximately 10% of the diameter D1(seeFIG. 14) of the end panel222.

The sixth ridge244, located radially outwardly from the fifth ridge242, is located a distance d14from the sidewall222. In one embodiment, the distance d14is between approximately 0.2 inches and 0.25 inches. In another embodiment the distance d14is approximately 0.236 inches. In one embodiment, the distance d14is between approximately 6% and approximately 10% of the diameter D1(seeFIG. 14) of the end panel222. In another embodiment, the distance d14is approximately 8% of the diameter D1(seeFIG. 14) of the end panel222.

In one embodiment, the diameter D1of the end panel226is generally the same as the diameter D1of the end panel26.

In one embodiment, embodiments of the elastic portions28,228may be formed from a different material than the rest of the end panels26,226, e.g., formed from non-metal material. In one embodiment, the elastic portions28,228may be formed from plastic. In another embodiment, the elastic portions28,228may be formed from rubber.

In one embodiment, container bodies including end panels such as, e.g., end panels26,126,226may be filled, sealed, and heated by induction heating systems such as, e.g., induction heating systems described in U.S. patent application Ser. No. 13/832,573, entitled “Induction Heating System for Food Containers and Method,” filed on Mar. 15, 2013, which is incorporated herein in its entirety by reference. However, container bodies including panels26,126,226are configured such that the container bodies may be heated by, e.g., induction heating, without locating the container bodies in a pressurized environment, e.g., overpressure. Additionally, the container bodies including end panels26,126,226are configured such that the container bodies may be heated, e.g., by induction heating, without the use of apparatuses to physically support the containers to resist outward deformation as the container body is heated.

Referring toFIG. 17, a can heating system310is shown according to an exemplary embodiment. System310includes a container mover or can mover, shown as conveyor312, that is configured to move cans314through the various portions of system310. In the embodiment shown inFIG. 17, a plurality of cans314are shown located next to each other along conveyor312, such that each can314moves sequentially through the various sections of system310. The cans314include end panels such as the end panels26,126,226, described above, configured to vary the volume of the interior of the cans314under various conditions. In the exemplary embodiment shown, system310includes a preheating section, shown as preheating chamber316, a first heating section, shown as heating chamber318, a second heating section, shown as heating chamber320, and a cooling section, shown as cooling chamber322. In the illustrated embodiment, neither of heating chambers18and20are pressurized. An airlock, such as first airlock324, need not be utilized between preheating chamber316and heating chamber318. Additionally, a second airlock326is illustrated but need not be utilized as heating chambers18and20are not pressurized.

Chambers318and320are unpressurized chambers that are configured to heat the cans within the chamber to a maximum temperature such that the pressure of the contents within the can at the maximum temperature does not rupture, break or permanently deform the body of the can within the heating chamber at atmospheric pressure (i.e., without a pressurized chamber), with the end panels transitioning from a first configuration (e.g.,FIG. 8) to a second configuration (e.g.,FIG. 9). Physical support structures to engage the can body need not be provided. The heating chambers are unpressurized induction heating chambers and the cans (e.g., cans314) heated within the induction coils are configured with an end panel such as, e.g., end panels26,126,226, that transitions to a second configuration (e.g.,FIG. 9) under the internal heating pressure and remains in the second configuration until a punch or other machine pushes the end wall back in following heating.

Preheating chamber316is an initial heating area configured to raise the temperature of cans314above ambient temperature prior to the cans entering the primary heating chambers (e.g., heating chambers318and320). In the embodiment shown, preheating chamber316heats cans314using a non-induction heat sources (e.g., heat supplied from recycling heat from other portions of the system). The preheating provided by preheating chamber316lessens the amount of heating that must be applied to cans314within heating sections318and320. To raise cans314above ambient temperature preheating chamber316is maintained at a temperature above ambient temperature, but is generally lower than the cooking temperature or lower than the sterilization temperature of cans314. In one embodiment, the temperature within preheating chamber316is above ambient temperature in the location of system310. In various embodiments, the temperature within preheating chamber316is between 70 and 212 degrees Fahrenheit, specifically is between 90 and 170 degrees Fahrenheit, and more specifically is between 110 and 150 degrees Fahrenheit.

As shown inFIG. 17, preheating chamber316includes one or more passive heat sources. In some embodiments, the passive heat sources transfer excess heat from one section of system310into preheating chamber316providing energy to preheat cans314within chamber316. In one embodiment, system310includes a conduit328which transfers heat (e.g., heat air, heated water, other heated fluid, etc.) from cooling chamber322to preheating chamber316. Thus, in this embodiment, heat from cooling cans314within cooling chamber322is captured and transferred from cooling chamber322into preheating chamber316via conduit328. In addition, system310may include a helical coil cooling system330, and excess heat generated by helical coil cooling system330is transferred to preheating chamber316via a second conduit332. Preheating cans314within preheating chamber316utilizing excess heat from other portions of system310may reduce the amount of energy needed to heat within heating chambers318and320.

In another embodiment, preheating chamber316may include an induction heating coil to preheat cans314prior to entering the primary heating chambers.

Generally, heating chamber318includes a first induction heating coil, shown as helical induction coil334. Helical coil334is shown surrounding (e.g., wrapping around) conveyor312such that conveyor312passes through a central lumen336or passage defined by the inner surface of helical coil334. In the embodiment shown, central lumen336is a substantially cylindrical space bounded by coil334. Cans314move through the lumen of helical coil334on conveyor312such that cans314move sequentially through heating chamber318.

Coil334is a coil formed from an electrically conductive material (e.g., copper, hollow copper tube, etc.) such that application of an alternating current to coil334generates an alternating magnetic field within lumen336of coil334. In the embodiment shown, cans314are made from a electrically conductive material, specifically a metal material, such that the magnetic field generated within coil334induces current (e.g., eddy currents) within the body and/or end walls (e.g., end panels of a three piece can, an integral end wall of a two piece can, etc.) of cans314. In one embodiment, cans314are made from an iron-based material, and in a specific embodiment, cans314are made from a steel material. In another embodiment, cans314may be formed from a non-electrically conductive material (e.g., a plastic material) with embedded electrically conductive structures and/or suseptors (i.e., embedded material or elements which can have current induced by coil334and which generates heat via resistive heating). The induced current causes resistive heating of the body and end walls of cans314, which in turn heats the contents of can314.

Because cans314are hermetically sealed cans, as the contents of can314heat up, the pressure within each can314increases which exerts outwardly directed forces on the body and end walls of cans314. In one embodiment, heating chamber318is configured to heat the contents of cans314to between 230 degrees and 260 degrees Fahrenheit, and is configured to be pressurized to between 10 psi and 25 psi. In another embodiment, heating chamber318is configured to heat the contents of cans314to between 217 degrees and 310 degrees Fahrenheit, and is configured to be pressurized to between 15 psi and 90 psi. In one embodiment, heating chamber318is part of system for heating high acid foods and is configured to heat the contents of cans314to between 170 degrees and 195 degrees Fahrenheit.

In the embodiment shown inFIG. 17, system310includes a second heating chamber, shown as heating chamber320. Heating chamber320includes a second induction heating coil, shown as helical induction coil338, defining a lumen340. Heating chamber320and coil338function substantially the same as heating chamber318and coil334discussed above, such that cans314are heated by the resistive heating of the can body and/or end walls of cans314within the alternating magnetic field generated by coil338.

In one embodiment, heating chamber320is configured to heat cans314to a higher temperature than heating chamber318to finish the cooking and/or sterilization of cans14. Thus, in such embodiments, heating chamber320is configured to continue the heating started by heating chamber318. In such embodiments, heating chamber320is configured to finish heating the contents of cans314to between 230 degrees and 260 degrees Fahrenheit, and is configured to be pressurized to between 10 psi and 25 psi. In another embodiment, heating chamber320is configured to finish heating the contents of cans314to between 217 degrees and 310 degrees Fahrenheit, and is configured to be pressurized to between 15 psi and 90 psi. In one embodiment, heating chamber320is part of system for heating high acid foods and is configured to heat the contents of cans314to between 170 degrees and 195 degrees Fahrenheit. Higher heating may be accomplished within chamber20by varying the heating properties of coil338. For example, in one embodiment, the coil density of coil338(i.e., the number of rotations of coil per unit length of coil) is greater than the coil density of coil334. In another embodiment, the frequency of the current within coil338(and consequently the frequency of the alternating magnetic field) and/or the amount of current within coil338is greater than the frequency and/or current within coil334.

In various embodiments, sealed cans314may be subjected to induction heating within the induction coil of chamber318and/or320for between 10 seconds and 4 minutes, specifically between 15 seconds and 3 minutes, and more specifically between 20 seconds and 2 minutes. Then, following heating for the selected time, the can may be removed from the induction field to allow the heat imparted to the can while within the induction coil to transfer throughout the contents of the can to finish heating of the contents.

As shown inFIG. 17, conveyor312carries cans314through lumens336and340of induction coils334and338, respectively. In this configuration, the portions of conveyor312located within coils334and338are formed from a non-electrically conductive material. Specifically, conveyor312may be formed from high strength, temperature tolerant polymer materials.

Cooling chamber322is a chamber that holds cans314while the cans cool to a temperature suitable for handling and processing upon exiting system310.

In the embodiment shown cooling chamber322includes two separate, sub-cooling chambers, shown as unpressurized cooling chamber323, and unpressurized cooling chamber325.

As shown inFIG. 1, system310includes an induction coil cooling system330. Induction coil cooling system330acts to cool coils334and338during heating. Cooling of coils334and338helps to lower the resistance of the material of the coils and consequently also lowers the power consumption during generation of the magnetic fields resulting in higher heating efficiencies. In various embodiments, coil cooling system330includes a helical conduit that surrounds coils334and338and provides a channel for supplying cooling fluid to the outer surface of coils334and338. In one embodiment, the cooling fluid is cooled air, and in another embodiment the cooling fluid is a liquid such as water. After extracting heat from coils334and/or338, the cooling fluid (now heated from coils334and/or338) is redirected to preheating chamber316where the extracted heat from the coils acts to raise the temperature within preheating chamber316. In various embodiments coil cooling system330is a refrigeration system (e.g., a compressor-based system), and in this embodiment, induction coil cooling system330is a closed circuit moving cooling fluid along coils334and338. In such an embodiment, the heat generated by the components (e.g., the compressor) of the refrigeration system is supplied to preheating chamber316via conduit332to raise the temperature within preheating chamber316.

The geometry of coils334and338may be selected to improve or maximize current induction within cans314. For example, the coil density (i.e., the number of coil rotations per unit distance), the coil diameter, and the cross-sectional shape of the helical coil (e.g., circular, elliptical, rectangular, square, etc.) may be selected to improve current induction for a particular application. For example, as shown inFIG. 1, coils334and338are round or circular helical coils. However, in other embodiments other shapes or types of induction coils can be used. For example, in one embodiment, coils334and338are square or rectangular shaped coils. In addition, in one embodiment, the cross-sectional geometry of the induction coil is a non-regular shape.

WhileFIG. 17, shows system310including two separate heating sections, system310may include more or less than two heating sections. System310may include more than two heating sections to heat products that require, for example, higher heating temperatures, longer heating times and/or alternating cycles of high heat, low heat and/or no heat. In other embodiments, system310may include a single heating chamber, such as either heating chamber318or320, configured to heat cans314to the desired temperature for a particular product or application.

In steam based heating systems multiple chambers at different pressures are typically needed because pressure and temperature are interrelated in steam based heating systems (e.g., higher temperature produces higher pressure). In contrast to steam systems, system310utilizing induction coil heating allows that the temperature of cans314to be controlled (e.g., actively controlled) independent of pressure within the heating chamber. Thus, system310allows the heating chamber not to be pressurized, e.g., no overpressure. Because the heating temperature within the induction coil-based heating chambers is not dependent on an elevated pressure within the heating chamber, use of the induction heating coils discussed herein allows for the heating chamber to be unpressurized.

System310is configured to provide efficient heating of cans314utilizing one or more induction coils, such as coil334or coil338. For example, as discussed above, conduits328and332transfer excess heat from other sections of system310into preheating chamber316to preheat cans314prior to entry to the main heating chambers.

In addition, conveyor312may be configured to facilitate transfer of heat from the can body and/or end walls of cans314through the contents of can314. In one embodiment, conveyor312is configured to cause rotation of cans314about the longitudinal axis of each can, as cans314move through at least heating sections318and320. It should be understood, that as used herein the longitudinal axis of cans314is the axis of the can perpendicular to and passing through the center point of the can end wall of each can. In various embodiments, conveyor312may be configured to rotate cans about the can's longitudinal axis at relatively fast rotational rates.

In addition, conveyor312may be configured to oscillate or agitate cans314to facilitate heat transfer within the contents of the can. The oscillation or agitation generated by conveyor312may be provided in addition to or in place of rotation of cans314. In one embodiment, conveyor312is configured to cause end over tumbling and/or twisting of cans314as cans move along conveyor312.

In various embodiments, system310is configured to orient cans314within induction coils334and338and consequently, to orient cans314relative to the magnetic field generated by the induction coils334and338in a manner that increases the heating efficiency between the interaction of the magnetic field and the electrically conductive metal material of cans314.FIG. 17depicts an exemplary embodiment of one such orientation. As shown inFIG. 17, cans314are positioned such that the longitudinal axis of cans314is substantially perpendicular (e.g., within 10 degrees of perpendicular, and in another embodiment, within 5 degrees of perpendicular) to the longitudinal axis of coils334and338. It is believed that this orientation exposes a greater volume of metal within the body and end walls of cans314to interaction (i.e., magnetic coupling) with the magnetic fields generated by coils334and338which in turns results in results in better can heating than some other potential orientations.

Cans and containers discussed herein may include containers of any style, shape, size, etc. For example, the containers discussed herein may be shaped such that cross-sections taken perpendicular to the longitudinal axis of the container are generally circular. However, in other embodiments the sidewall of the containers discussed herein may be shaped in a variety of ways (e.g., having other non-polygonal cross-sections, as a rectangular prism, a polygonal prism, any number of irregular shapes, etc.) as may be desirable for different applications or aesthetic reasons. In various embodiments, the sidewall of cans14may include one or more axially extending sidewall sections that are curved radially inwardly or outwardly such that the diameter of the can is different at different places along the axial length of the can, and such curved sections may be smooth continuous curved sections. In one embodiment, cans14, such as can154, may be hourglass shaped. Cans14may be of various sizes (e.g., 3 oz., 8 oz., 12 oz., 15 oz., 28 oz, etc.) as desired for a particular application.

In various embodiments, the can ends described above may be various different types of can ends (e.g., a closure, lid, cap, cover, top, end, can end, sanitary end, “pop-top”, “pull top”, convenience end, convenience lid, pull-off end, easy open end, “EZO” end, etc.). The can end end may be any element that allows the container to be sealed such that the container is capable of maintaining a hermetic seal. Various embodiments of can ends may have various different mechanisms for opening and/or removal. In an exemplary embodiment, the upper can end may be an “EZO” convenience end, sold under the trademark “Quick Top” by Silgan Containers Corp.

The can ends52and126shown inFIGS. 7-11coupled to the sidewall via a “double seam” formed from the interlocked portions of material of the can sidewall and the can end. However, in other embodiments, the can ends discussed herein may be coupled to the sidewall via other mechanisms. For example, can ends may be coupled to the sidewall via welds or solders.

In various embodiments, the can end52may be a closure or lid attached to the body sidewall mechanically (e.g., snap on/off closures, twist on/off closures, tamper-proof closures, snap on/twist off closures, etc.). In another embodiment, the can end52may be coupled to the container body via the pressure differential. The container end may be made of metals, such as steel or aluminum, metal foil, plastics, composites, or combinations of these materials. In various embodiments, the can ends, double seams, and sidewall of the container are adapted to maintain a hermetic seal after the container is filled and sealed.

The containers discussed herein may be used to hold perishable materials (e.g., food, drink, pet food, milk-based products, etc.). It should be understood that the phrase “food” used to describe various embodiments of this disclosure may refer to dry food, moist food, powder, liquid, or any other drinkable or edible material, regardless of nutritional value. In other embodiments, the containers discussed herein may be used to hold non-perishable materials or non-food materials. In various embodiments, the containers discussed herein may contain a product that is packed in liquid that is drained from the product prior to use. For example, the containers discussed herein may contain vegetables, pasta or meats packed in a liquid such as water, brine, or oil.

According to various exemplary embodiments, the inner surfaces of the can ends, end panels, and the sidewall may include a liner (e.g., an insert, coating, lining, a protective coating, sealant, etc.). The protective coating acts to protect the material of the container from degradation that may be caused by the contents of the container. In an exemplary embodiment, the protective coating may be a coating that may be applied via spraying or any other suitable method. Different coatings may be provided for different food applications. For example, the liner or coating may be selected to protect the material of the container from acidic contents, such as carbonated beverages, tomatoes, tomato pastes/sauces, etc. The coating material may be a vinyl, polyester, epoxy, EVOH and/or other suitable lining material or spray. The interior surfaces of the container ends may also be coated with a protective coating as described above.

While the current application recites particular combinations of features in the claims appended hereto, various embodiments of the invention relate to any combination of any of the features described herein whether or not such combination is currently claimed, and any such combination of features may be claimed in this or future applications. Any of the features, elements, or components of any of the exemplary embodiments discussed above may be used alone or in combination with any of the features, elements, or components of any of the other embodiments discussed above.