Micro-expansion tank body with rolling ribs, micro-expansion packaging metal tank and bulging die
By surrounding at least 90% of the area of the drum-shaped structure of the metal can, combined with the design of thin metal materials and swelling molds, the problem of the metal can easily become weak during transportation is solved, and high strength is achieved. The low cost and anti-shrink tank capability are improved while avoiding appearance defects.
Patent Information
- Application Number
- CN202420993682.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-09
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-05-09
AI Technical Summary
Existing metal tanks are prone to deflated tank problems during transportation. In the existing technology, such as material thickening, tank body rolling tendons, slightly swelling and swelling tendons, and the swelling tendons can easily lead to appearance defects.
Using a slightly expanded can body structure with rolling ribs, by setting rolling ribs around at least 90% of the area on the drum-shaped structure of the can body, combining the design of thin metal materials and the swelling mold to form a high-strength, low-cost swelling Packaging metal cans.
It effectively enhances the strength of the can body, reduces material costs, improves the ability to resist the deflation, and avoids the appearance scratches at the swelling ribs.
Smart Images
Figure CN222474726U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a packaging metal can, in particular to a slightly bulging can body and a slightly bulging packaging metal can. Background Art
[0002] In order to prevent metal cans from deflation during transportation, the following methods are currently used:
[0003] Material thickening: Different thickness materials can be selected according to needs. The thicker the material, the more effective its strength can be. However, thickening the material to improve the strength of the can body will undoubtedly increase the material cost.
[0004] Can body rolling: Through the rolling die, in the rolling process, the straight can body is formed with regular circular indentations that are concave inwards, which effectively improves the strength of the can body, but it is still difficult to completely avoid can deflation.
[0005] Slight expansion of the can body: The can body is expanded to form a slight arch through the expansion mold, which increases its radial pressure-bearing strength. Although this structure can prevent the can from deflation to a certain extent, it will still cause deflation after being hit or squeezed during transportation.
[0006] Can body expansion: Through the expansion mold, the can body is expanded and convex ribs are directly formed on the can body to improve its strength. For this method of can body expansion, the ribs bulge outward on the can body, and the convex rib part will become the maximum outer diameter of the can body. During transportation, friction will occur between the can bodies, resulting in scratches on the surface of the ribs, forming appearance defects, affecting product sales.
[0007] Therefore, there is an urgent need for a metal can structure that can solve the above problems and further improve the strength of the metal can. Utility Model Content
[0008] The utility model aims to provide a slightly bulging can body with rolling ribs, a slightly bulging packaging metal can and a bulging mold for making the slightly bulging can body. The slightly bulging can body is made thinner, has higher strength, low cost and strong anti-can collapse capability.
[0009] In order to achieve the above-mentioned purpose, the utility model provides a slightly expanded can body with rolling ribs, including a can body body with a thin metal skin, the can body body is annular, and its axial middle area radially protrudes outward to form a drum-shaped structure, the outer surface of the drum-shaped structure is concave with one or more rolling ribs surrounding at least a part of the drum-shaped structure along the circumference of the drum-shaped structure, and at least one rolling rib is distributed around at least 90% of the circumference of the drum-shaped structure; wherein the rolling ribs are horizontally arranged around the circumference of the drum-shaped structure or obliquely arranged around the circumference of the drum-shaped structure.
[0010] Preferably, the rolling rib is an annular rolling rib horizontally surrounding the drum-shaped structure, and there are a plurality of the rolling ribs arranged at axial intervals along the drum-shaped structure.
[0011] Preferably, the rolling ribs are arc-shaped rolling ribs surrounding a portion of the circumferential area of the drum-shaped structure. The arc-shaped rolling ribs are distributed around the circumferential direction of the drum-shaped structure and are distributed along the axial direction of the drum-shaped structure to be obliquely arranged on the drum-shaped structure. All the arc-shaped rolling ribs cover at least 90% of the circumferential area of the drum-shaped structure and at least 80% of the axial area. Such arc-shaped rolling ribs are irregular expansion ribs, which can form regional strength enhancement on the can body as needed, enhance the area where the can body strength is weak, and can completely retain the main display surface of the can body without affecting the visual effect of the front of the product.
[0012] Specifically, both ends of the arc-shaped rolling bead gradually become shallower and / or narrower to form a progressive groove.
[0013] Specifically, there are two arc-shaped rollers and they are crescent-shaped, the gaps at both ends of the two arc-shaped rollers are relative or connected, and the bow of one arc-shaped roller is upward and arranged at the middle and upper position of the drum-shaped structure, and the bow of the other arc-shaped roller is downward and arranged at the middle and lower position of the drum-shaped structure.
[0014] Specifically, the middle of the arc-shaped rolling rib is located at the lower end or the lower middle position of the drum-shaped structure, and the two ends of the arc-shaped rolling rib gradually extend outward around the circumference of the drum-shaped structure and extend upward along the axial direction of the drum-shaped structure, so that the gaps at the two ends of the arc-shaped rolling rib are relative or connected.
[0015] Specifically, the arc-shaped rolling rib includes a first rolling rib, a second rolling rib and a third rolling rib. The middle of the first rolling rib is located at the lower end or the lower middle position of the drum-shaped structure, and the two ends gradually extend outward around the circumference of the drum-shaped structure and extend upward along the axial direction of the drum-shaped structure, so that the gaps at the two ends of the first rolling rib are relative or connected. The second rolling rib and the third rolling rib are C-shaped and are located at the lower positions on both sides of the first rolling rib. The first rolling rib and the second rolling rib.
[0016] Specifically, the cross section of the rolling rib is arc-shaped or rectangular with chamfered corners.
[0017] Wherein, the can body is a tinplate can body.
[0018] Wherein, the thickness of the can body is less than or equal to 0.23 mm.
[0019] The utility model also provides a slightly bulging packaging metal can, comprising a can body, a bottom cover and an upper cover, wherein the can body is the slightly bulging can body as described above, the bottom cover is installed or integrally formed at the bottom opening of the can body, and the upper cover is installed at the top opening of the can body.
[0020] The utility model also provides a rolling rib micro-expansion mold for a metal can body, which is used to form the micro-expansion can body as described above, and includes a plurality of strip-shaped forming molds protruding outward in the middle, and the plurality of strip-shaped forming molds are surrounded in a circle to form a bulging mold, and the outwardly protruding portion of the bulging mold matches the drum-shaped structure and is inwardly recessed to form an inner groove matching the rolling rib.
[0021] The utility model also provides a micro-expansion die for a metal can body, which is used to form the micro-expansion can body as described above, and includes a plurality of strip forming dies protruding outward in the middle and a rib rolling die. The plurality of strip forming dies surround a bulging die in a circle, and the outward protruding portion of the bulging die matches the drum-shaped structure. The rib rolling die matches the shape of the bulging die and is inwardly recessed to form an inner groove matching the rib rolling.
[0022] Compared with the prior art, the utility model sets a rolling rib structure on the micro-expansion can body that surrounds at least 90% of the circumference of the drum-shaped structure, so that the micro-expansion can body can be made of thinner materials and has higher strength, effectively enhancing the strength of the weak position of the can body, not only reducing the cost of metal cans, but also effectively improving the ability of metal cans to resist deflation during transportation. Furthermore, the rolling ribs on the micro-expansion can body of the utility model are inner concave rolling ribs, and during transportation observation, it is not easy to cause scratches on the surface of the expansion ribs due to friction of the can body, forming appearance defects. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a three-dimensional diagram of the slightly expanded packaging metal can in Example 1 of the utility model.
[0024] Figure 2 It is a side view of the slightly expanded packaging metal can in Example 1 of the utility model.
[0025] Figure 3 This is a simulation test diagram of the compression resistance of the micro-expansion packaging metal can of the utility model.
[0026] Figure 4 It is a structural diagram of a micro-expansion mold in one embodiment of the utility model.
[0027] Figure 5 and Figure 6 It is a structural diagram of a micro-expansion mold in another embodiment of the utility model.
[0028] Figure 7 It is a three-dimensional diagram of the slightly expanded packaging metal can in Example 2 of the utility model.
[0029] Figure 8 It is a side view of a slightly expanded packaging metal can at one angle in Example 2 of the utility model.
[0030] Fig. 9 It is a side view of the slightly expanded packaging metal can in Example 2 of the utility model from another angle.
[0031] Fig.10 It is a three-dimensional diagram of the slightly expanded packaging metal can in Example 3 of the utility model.
[0032] Fig.11 It is a side view of a slightly expanded packaging metal can at one angle in Example 3 of the utility model.
[0033] Fig.12 It is a side view of the slightly expanded packaging metal can in Example 3 of the utility model from another angle.
[0034] Fig.13 It is a three-dimensional diagram of the slightly expanded packaging metal can in Example 4 of the utility model.
[0035] Fig.14 It is a side view of a slightly expanded packaging metal can at one angle in Example 4 of the utility model.
[0036] Fig.15 It is a side view of the slightly expanded packaging metal can in Example 4 of the utility model from another angle.
[0037] Fig.16 It is a three-dimensional diagram of the slightly expanded packaging metal can in Example 5 of the utility model.
[0038] Fig.17 It is a side view of a slightly expanded packaging metal can at one angle in Example 5 of the utility model.
[0039] Fig.18 It is a side view of the slightly expanded packaging metal can in Example 5 of the utility model from another angle. DETAILED DESCRIPTION
[0040] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation modes and the accompanying drawings.
[0041] Embodiment 1:
[0042] refer to Figure 1 and Figure 2 The utility model discloses a slightly expanded packaging metal can, comprising a can body 100, a bottom cover 200 and an upper cover 300, wherein the bottom cover 200 is installed or integrally formed at the bottom opening of the can body 100, and the upper cover 300 is installed at the top opening of the can body 100.
[0043] refer to Figure 1 and Figure 2 The can body 100 includes a can body 10 of a thin metal skin, the middle of the can body 10 protrudes outward to form a drum-shaped structure 11, and a rolling rib 12 surrounding the drum-shaped structure 11 is arranged on the drum-shaped structure 11. The rolling rib 12 has one or more and is concave in the outer surface of the drum-shaped structure 11. At least 90% of the circumference of the drum-shaped structure 11 passes through at least one rolling rib 12, that is, all the rolling ribs 12 together cover at least 90% of the circumference of the drum-shaped structure 11.
[0044] The rolling rib 12 is an annular rolling rib 12 horizontally surrounding the drum-shaped structure 11, and there are multiple rolling ribs 12 arranged at axial intervals along the drum-shaped structure 11. Therefore, in this embodiment, each rolling rib 12 passes through all circumferential areas of the drum-shaped structure 11.
[0045] In this embodiment, there are three rolling ribs 12. Of course, the number of rolling ribs 12 is not limited to 3, and can also be 2, 4, etc., which can be set according to the height of the drum-shaped structure 11 and the width of the rolling ribs 12.
[0046] In this embodiment, the three rolling ribs 12 are arranged at equal intervals. Of course, the three rolling ribs 12 can also be arranged at unequal intervals.
[0047] In this embodiment, the cross section of the rolling rib 12 is arc-shaped or rectangular with chamfered corners.
[0048] The can body 10 is a tinplate can body 10 .
[0049] The thickness of the can body 10 is less than or equal to 0.23 mm. In this embodiment, the thickness of the can body 10 is 0.23 mm. Of course, the thickness of the material used for the can body 10 can also be 0.17 mm, 0.19 mm, 0.21 mm, etc.
[0050] refer to Figure 3 , which is the compression simulation result of the can body of the utility model micro-expansion packaging metal can (micro-expansion rolled can in the figure) compared with the micro-expansion can with a thickness of 0.23mm and the straight can with a thickness of 0.25mm. It can be seen from the figure that when a force of 30kgf is applied, the deformation of the micro-expansion rolled can is significantly smaller than that of the other two can bodies.
[0051] refer to Figure 4The utility model also discloses a micro-expansion mold for forming the can body 100 as described above, including a plurality of strip-shaped forming molds 21 protruding outward in the middle, and the plurality of strip-shaped forming molds 21 surround a circle to form a bulging mold 20, and the protruding portion of the bulging mold 20 matches the drum-shaped structure 11 and is inwardly concave to form an inner groove 22 matching the rolling rib 12. When the can body is bulged, the strip-shaped forming molds 21 are controlled to expand outward respectively, so that the can body 10 is slightly convex outward to form the drum-shaped structure 11, and the drum-shaped structure 11 is subjected to inward concave bulging.
[0052] refer to Figure 5 and Figure 6 The utility model also discloses a micro-expansion mold for forming the can body 100 as described above, including a plurality of strip forming molds 21a protruding outward in the middle and a rib rolling mold 20b, wherein the plurality of strip forming molds 21a surround a circle to form a bulging mold 20a, wherein the protruding portion of the bulging mold 20a matches the drum-shaped structure 11, and the outer surface of the strip forming mold is a smooth surface, and the rib rolling mold 20b matches the shape of the bulging mold 20a and is concave inwardly to form an inner groove 21b matching the rib rolling 12. When the can body is bulged, the strip forming molds 21a are controlled to expand outwardly respectively, so that the can body 10 is slightly convex outward to form the drum-shaped structure 11, and then the drum-shaped structure 11 of the can body 10 with a curvature is ribbed by the rib rolling mold 20b exclusive to the bulging can.
[0053] Embodiment 2:
[0054] refer to Figures 7 to 9 , which is different from Example 1, in the slightly expanded packaging metal can, the can body 100a includes a can body main body 10a, the can body main body 10a includes a drum-shaped structure 11a, and the drum-shaped structure 11a has arc-shaped rolling ribs 121a and arc-shaped rolling ribs 122a, the arc-shaped rolling ribs 121a and arc-shaped rolling ribs 122a respectively surround a circumferential portion of the drum-shaped structure 11a, and are distributed circumferentially around the drum-shaped structure 11a and axially along the drum-shaped structure 11a so as to be obliquely arranged on the drum-shaped structure 11a.
[0055] The middle of the arc-shaped rolling rib 121a and the arc-shaped rolling rib 122a gradually narrows toward both sides, and the two ends of the arc-shaped rolling rib 121a and the arc-shaped rolling rib 122a gradually become shallower and narrower to form a progressive groove.
[0056] Among them, the arc-shaped rolling ribs 121a and the arc-shaped rolling ribs 122a are distributed at different positions around the drum-shaped structure 11a, and the arc-shaped rolling ribs 121a and the arc-shaped rolling ribs 122a are distributed together in at least 90% of the area around the drum-shaped structure 11a, with only a very small processing gap between the two ends.
[0057] More preferably, the two ends of the arcuate roller rib 121a and the arcuate roller rib 122a are respectively located at the first position and the second position, and the first position and the second position are located at two opposite sides of the drum-shaped structure 11a in the circumferential direction and are located at the middle upper position and the middle lower position in the axial direction (height direction). The middle of the arcuate roller rib 121a gradually bends upward to form a crescent-shaped structure with a notch downward, and the middle of the arcuate roller rib 122a gradually bends downward to form a crescent-shaped structure with a notch upward. This solution allows the arcuate roller rib 121a and the arcuate roller rib 122a to be distributed in an area close to 100% of the circumferential area of the drum-shaped structure 11a, and also allows the arcuate roller rib 121a and the arcuate roller rib 122a to be distributed in an area of more than 80% of the axial area of the drum-shaped structure 11a, effectively ensuring the strength of the drum-shaped structure 11a.
[0058] The drum-shaped structure 11a occupies more than 70% of the can body in the axial direction.
[0059] Embodiment 3:
[0060] refer to Figures 10 to 12 , which is different from Example 1, in the slightly expanded packaging metal can, the can body 100b includes a can body main body 10b, the can body main body 10b includes a drum-shaped structure 11b, and the drum-shaped structure 11b has an arc-shaped rolling rib 12b, which surrounds most or all of the circumferential area of the drum-shaped structure 11b, is distributed around the circumferential direction of the drum-shaped structure 11b, and is distributed along the axial direction of the drum-shaped structure 11b so as to be obliquely arranged on the drum-shaped structure 11b.
[0061] The gaps at both ends of the arcuate rolling rib 12b are relative or connected so that the arcuate rolling rib 12b is closed. When the two ends of the arcuate rolling rib 12b are connected, the arcuate rolling rib 12b will obliquely surround the circumference of the drum-shaped structure 11b.
[0062] The arc-shaped rolling rib 12b is low in the middle, and both ends gradually extend circumferentially around the drum-shaped structure 11b and extend upward along the axial direction of the drum-shaped structure 11b to form an irregular arc.
[0063] Specifically, the middle depth of the arc-shaped rolling rib 12b is greater than the depths at both ends of the arc-shaped rolling rib 12b. The depths at both ends of the arc-shaped rolling rib 12b gradually become shallower.
[0064] In one embodiment, the depth of the middle of the arc-shaped rolling rib 12b gradually becomes shallower while extending toward both ends. In another embodiment, the depth of the middle area of the arc-shaped rolling rib 12b is the same, and the depth of both ends gradually becomes shallower.
[0065] In this embodiment, there is one arc-shaped rolling rib 12b.
[0066] Embodiment 4:
[0067] refer to Figures 13 to 15 , which is different from Example 1, in the slightly expanded packaging metal can, the can body 100c includes a can body main body 10c, the can body main body 10c includes a drum-shaped structure 11c, and the drum-shaped structure 11c has an arc-shaped rolling rib 12c, which surrounds most or all of the circumferential area of the drum-shaped structure 11c, and is distributed circumferentially around the drum-shaped structure 11c and axially along the drum-shaped structure 11c so as to be obliquely arranged on the drum-shaped structure 11c.
[0068] The gaps at both ends of the arc-shaped rolling rib 12c are relative or connected so that the arc-shaped rolling rib 12c is in a closed shape.
[0069] The arc-shaped rolling rib 12c is low in the middle, and both ends gradually extend circumferentially around the drum-shaped structure 11c and extend upward along the axial direction of the drum-shaped structure 11c to form an irregular arc.
[0070] Specifically, the middle depth of the arc-shaped rolling bead 12c is greater than the depth at both ends of the arc-shaped rolling bead 12c. The depth at both ends of the arc-shaped rolling bead 12c gradually becomes shallower. Of course, the rolling bead depths of the arc-shaped rolling bead 12c can also be consistent.
[0071] In one embodiment, the depth of the middle of the arc-shaped rolling rib 12c gradually becomes shallower while extending toward both ends. In another embodiment, the depth of the middle area of the arc-shaped rolling rib 12c is the same, and the depth of both ends gradually becomes shallower.
[0072] In this embodiment, there are two arc-shaped rolling ribs 12b arranged side by side.
[0073] Embodiment 5:
[0074] refer to Figures 16 to 18 , which is different from Example 1, in the slightly expanded packaging metal can, the can body 100d includes a can body main body 10d, the can body main body 10d includes a drum-shaped structure 11d, and the drum-shaped structure 11d has arc-shaped rolling ribs 121d, arc-shaped rolling ribs 122d, and arc-shaped rolling ribs 123d. The arc-shaped rolling ribs 12d surround most or all of the circumferential areas of the drum-shaped structure 11d, and are distributed circumferentially around the drum-shaped structure 11d while being distributed axially along the drum-shaped structure 11d to be obliquely arranged on the drum-shaped structure 11d.
[0075] The two ends of the arc-shaped rolling rib 121d are connected so that the arc-shaped rolling rib 121d is closed and is arranged circumferentially around the drum-shaped structure 11d. The middle of the arc-shaped rolling rib 121d is low, and the two ends gradually extend circumferentially around the drum-shaped structure 11d and extend upward along the axial direction of the can body to form an irregular arc. Specifically, the middle depth of the arc-shaped rolling rib 121d is greater than the depth at the two ends of the arc-shaped rolling rib 121d. The depth at the two ends of the arc-shaped rolling rib 121d gradually becomes shallower.
[0076] In one embodiment, the depth of the arc-shaped rolling rib 121d in the middle gradually becomes shallower while extending toward both ends. In another embodiment, the depth of the arc-shaped rolling rib 121d in the middle is the same, and the depth of both ends gradually becomes shallower. Of course, the depth of the arc-shaped rolling rib 121d can also be the same.
[0077] The arcuate rolling ribs 122d and 123d are C-shaped and are respectively located below the two sides of the arcuate rolling ribs 121d. The depths of the arcuate rolling ribs 122d and 123d can be the same, or can gradually become shallower from the middle to the two sides.
[0078] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.
Claims
1. A slightly expanded can body with rolled ribs, characterized in that: A can body including a thin metal skin, wherein the can body is annular, and an axial middle area thereof radially protrudes outward to form a drum-shaped structure, and an outer surface of the drum-shaped structure is concave with one or more ribs surrounding at least a portion of the drum-shaped structure along the circumference of the drum-shaped structure, and at least one rib is distributed around at least 90% of the circumference of the drum-shaped structure; The rolling ribs are horizontally arranged around the circumference of the drum-shaped structure or obliquely arranged around the circumference of the drum-shaped structure.
2. The micro-expansion can body according to claim 1, characterized in that: The rolling ribs are annular rolling ribs horizontally surrounding the drum-shaped structure. There are a plurality of rolling ribs arranged at axial intervals along the drum-shaped structure.
3. The micro-expansion can body according to claim 1, characterized in that: The rolling ribs are arcuate rolling ribs surrounding a partial circumferential area of the drum-shaped structure. The arcuate rolling ribs are distributed around the circumference of the drum-shaped structure and are distributed along the axial direction of the drum-shaped structure to be obliquely arranged on the drum-shaped structure. All the arcuate rolling ribs together cover at least 80% of the axial area of the drum-shaped structure.
4. The slightly expanded can body according to claim 3, characterized in that: The two ends of the arc-shaped rolling bead gradually become shallower and / or narrower to form a progressive groove.
5. The slightly expanded can body according to claim 3, characterized in that: There are two arc-shaped rollers in a crescent shape, the gaps at both ends of the two arc-shaped rollers are opposite or connected, and one arc-shaped roller is arched upward and arranged at a middle upper position of the drum-shaped structure, and the other arc-shaped roller is arched downward and arranged at a middle lower position of the drum-shaped structure; or, The middle of the arcuate rolling rib is located at the lower end or the lower middle position of the drum-shaped structure, and the two ends of the arcuate rolling rib gradually extend outward around the circumference of the drum-shaped structure and extend upward along the axial direction of the drum-shaped structure, so that the gaps at the two ends of the arcuate rolling rib are relative or connected.
6. The micro-expansion can body according to claim 3, characterized in that: The arc-shaped rolling rib includes a first rolling rib, a second rolling rib and a third rolling rib. The middle of the first rolling rib is located at the lower end or the lower middle position of the drum-shaped structure. The two ends gradually extend outward around the circumference of the drum-shaped structure and extend upward along the axial direction of the drum-shaped structure, so that the gaps at the two ends of the first rolling rib are relative or connected. The second rolling rib and the third rolling rib are C-shaped and are located at the lower positions on both sides of the first rolling rib. The first rolling rib and the second rolling rib.
7. The micro-expansion can body according to claim 1, characterized in that: The cross section of the rolling rib is arc-shaped or rectangular with chamfered corners, the can body is a tinplate can body, and the thickness of the can body is less than or equal to 0.23 mm.
8. A slightly expanded packaging metal can, characterized in that: It comprises a can body, a bottom cover and an upper cover, wherein the can body is a slightly expanded can body as described in any one of claims 1 to 7, the bottom cover is installed or integrally formed at the bottom opening of the can body, and the upper cover is installed at the top opening of the can body.
9. A metal can body rolling micro-expansion die, used for forming a micro-expansion can body as claimed in any one of claims 1 to 7, characterized in that: It comprises a plurality of strip forming dies protruding outwards in the middle, and the plurality of strip forming dies are arranged around a circle to form a bulging die, and the outward protruding part of the bulging die matches the drum-shaped structure and is inwardly recessed to form an inner groove matching the rolling rib.
10. A bulging die for a metal can body, used for forming a slightly bulging can body as claimed in any one of claims 1 to 7, characterized in that: It includes several strip forming dies and rolling rib dies that protrude outward in the middle. Several of the strip forming dies are surrounded by a circle to form a bulging die. The outward protruding part of the bulging die matches the drum structure. The rolling rib die matches the shape of the bulging die and is recessed inward to form an inner groove that matches the rolling rib.