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Title:
SHELF SUPPORT BEAMS AND SHELVING UNITS UTILIZING SAME
Document Type and Number:
WIPO Patent Application WO/2020/219505
Kind Code:
A1
Abstract:
A shelf support beam (130) for use in a shelving unit (10) to support a shelf (22). A structural member (132) has a C-shaped cross-section. A web (144) separates a top flange (146) from a bottom flange (162). The top flange (146) is configured to support the shelf (22). The web (144), the top flange (146), and the bottom flange (162) define a channel (142). The channel (142) defines a cavity height (D1). The top flange (146) and the bottom flange (162) define a top flange width (D2) and a bottom flange width (D3), respectively. A ratio of the cavity height (D1 ) to a sum of the top flange width (D2) and the bottom flange width (D3) is greater than 1.707 or greater than 1.8. The cross-section has a moment of inertia of greater than 0.0613 or at least 0.0617. The web (144) includes a recessed region (164) in which the structural member (132) is offset in a direction into the channel (142). A centroid (148) of the cross-section is within 0.125 inch of the recessed region (164).

Inventors:
PARAB ROHAN (US)
LAMBER JEFF (US)
Application Number:
US2020/029247
Publication Date:
October 29, 2020
Filing Date:
April 22, 2020
Export Citation:
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Assignee:
EDSAL MFG COMPANY INC (US)
International Classes:
A47B47/00; A47B47/02; A47B96/02; A47B96/14
Foreign References:
GB952576A1964-03-18
US20180279782A12018-10-04
US201816130398A2018-09-13
US20190125077A12019-05-02
Attorney, Agent or Firm:
BENINTENDI, Steven, W. et al. (US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. A shelf support beam for use in a shelving unit to support a shelf comprising:

a structural member having a C-shaped cross-section and including a web separating a top flange that is configured to support the shelf from a bottom flange, the web, the top flange, and the bottom flange define a channel; wherein the channel, the top flange, and the bottom flange define a cavity height, a top flange width, and a bottom flange width, respectively, and wherein a ratio of the cavity height to a sum of the top flange width and the bottom flange width is greater than 1.707.

2. The shelf support beam of claim 1 wherein the C-shaped cross-section has a moment of inertia of greater than 0.0613.

3. The shelf support beam of claim 1 wherein the C-shaped cross-section has a moment of inertia is at least 0.0617.

4. The shelf support beam of claim 1 wherein the top flange includes a cap portion and a shelf support portion separated by a sidewall portion with the shelf support portion being configured to support the shelf and the sidewall portion being configured to prevent lateral movement of the shelf toward the web.

5. The shelf support beam of any one of claims 1 -4 wherein the ratio is greater than 1.8.

6. The shelf support beam of any one of claims 1 -4 wherein the cavity height is greater than 1.64 inches (4.166 centimeters) and is less than 3.656 inches (9.286 centimeters).

7. The shelf support beam of any one of claims 1 -4 wherein the C-shaped cross-section has a centroid and the centroid is within 0.125 inch (0.3175 centimeter) of the web.

8. The shelf support beam of any one of claims 1 -4 wherein the web includes a recessed region in which the structural member is offset in a direction into the channel.

9. The shelf support beam of claim 8 wherein the C-shaped cross-section has a centroid and the centroid is within 0.125 inch (0.3175 centimeter) of the recessed region.

10. The shelf support beam of claim 8 wherein the recessed region is at least 30% of an overall height of the structural member.

11. The shelf support beam of claim 8 wherein the recessed region is in a range of 30% to 70% of an overall height of the structural member.

12. The shelf support beam of claim 8 wherein the recessed region is about 70% of an overall height of the structural member.

13. The shelf support beam of any one of claims 1 -4 wherein the C-shaped cross-section has a gauge of 0.054 inch (0.1372 centimeter).

14. The shelf support beam of any one of claims 1 -4 wherein the C-shaped cross-section has a strip width of 3.656 inches (9.286 centimeters).

15. The shelf support beam of claim 14 wherein the C-shaped cross-section has a gauge of 0.054 inch (0.1372 centimeter).

16. A shelving unit comprising:

a plurality of posts;

a plurality of shelf support beams of any one of claims 1 -4 configured to be attached to two posts of the plurality of posts; and

the shelf configured to be supported on the shelf support beam after the shelf support beam is coupled to the two posts.

17. A method of manufacturing the shelf support beam of any one of claims 1 -4.

18. A shelf support beam for use in a shelving unit to support a shelf comprising:

a structural member having a C-shaped cross-section and including a web separating a top flange that is configured to support the shelf from a bottom flange, the web, the top flange, and the bottom flange define a channel, wherein the C-shaped cross-section has a moment of inertia greater than 0.0613.

19. The shelf support beam of claim 18 wherein the moment of inertia is at least 0.0617.

20. The shelf support beam of claim 18 or 19 wherein the C-shaped cross- section has a strip width of 3.656 inches.

21. The shelf support beam of claim 18 or 19 wherein the C-shaped cross- section has a gauge of 0.054 inch (0.1372 centimeter).

22. The shelf support beam of claim 18 or 19 wherein the top flange includes a cap portion and a shelf support portion separated by a sidewall portion with the shelf support portion being configured to support the shelf and the sidewall portion being configured to prevent lateral movement of the shelf toward the web.

23. The shelf support beam of claim 18 or 19 wherein the channel, the top flange, and the bottom flange define a cavity height, a top flange width, and a bottom flange width, respectively, and

wherein a ratio of the cavity height to a sum of the top flange width and the bottom flange width is greater than 1.707.

24. The shelf support beam of claim 23 wherein the ratio is at least 1.8.

25. The shelf support beam of claim 23 wherein the cavity height is greater than 1.640 inches.

26. A shelving unit comprising:

a plurality of posts;

a plurality of shelf support beams of any one of claims 18 or 19 configured to be attached to two posts of the plurality of posts; and

the shelf configured to be supported on the shelf support beam after the shelf support beam is coupled to the two posts.

27. A method of manufacturing the shelf support beam of claim 18 or 19.

Description:
SHELF SUPPORT BEAMS AND SHELVING UNITS UTILIZING SAME

Technical Field

[0001] This invention relates to shelving units and, more particularly, to shelf support beams to increase the load-bearing capacity of shelving units.

Background

[0002] Shelving units are commonly used for storing various items in a space-efficient manner. Such units typically include four vertical support posts arranged at corners of a generally rectangular pattern. Horizontal front and rear shelf support beams extend between the two front corner support posts and between the two rear corner support posts. Shorter horizontal shelf support beams are often positioned on opposing sides of the unit and extend between a front corner support post and a rear corner support post. In a conventional arrangement, such shelving units define multiple shelves and supporting beams one above the other with the corner support posts and shelf support beams of metal. For example, these components are often formed of sheet metal or steel and, in combination with shelves, are generally referred to as steel shelving or storage units.

[0003] As loads are applied to a shelving unit, such as by loading heavy items onto a shelf, each shelf may bow or bend. Bowing and bending beyond a limit can lead to shelving failure, particularly when bowing results in strain beyond the unit’s capacity. For example, undue bowing or bending of a shelving unit under load could permanently deform the shelf, allowing the shelf to pull away from the shelf support beams of the shelving unit thereby rendering the shelf and/or shelving unit inoperable for future use, or the shelf could catastrophically fail.

[0004] While metal shelving units are generally successful for their intended purpose and remain useful and popular with consumers, manufacturers and other providers continually strive to improve upon their design and load-carrying capacity. In this regard, it is desirable to significantly increase the load capacity of shelving units without a significant increase in manufacturing cost and/or without a significant increase in weight of the shelving unit. Summary

[0005] Embodiments in accordance with the invention address these and other deficiencies in conventional metal shelving units by at least significantly increasing the load capacity relative to existing metal shelving units without increasing related material or manufacturing costs. In one embodiment, a shelf support beam for use in a shelving unit to support a shelf includes a structural member having a C-shaped cross-section. In the cross-section, a web separates a top flange that is configured to support the shelf from a bottom flange. The web, the top flange, and the bottom flange define a channel. The channel, the top flange, and the bottom flange further define a cavity height, a top flange width, and a bottom flange width, respectively. A ratio of the cavity height to a sum of the top flange width and the bottom flange width is greater than 1.707.

[0006] In one embodiment, the C-shaped cross-section has a moment of inertia of greater than 0.0613.

[0007] In one embodiment, the C-shaped cross-section has a moment of inertia of at least 0.0617.

[0008] In one embodiment, the ratio is greater than 1.8.

[0009] In one embodiment, the cavity height is greater than 1.640 inches

(4.166 centimeters) and is less than 3.656 inches (9.286 centimeters).

[0010] In one embodiment, the C-shaped cross-section has a centroid and the centroid is within 0.125 inch (0.3175 centimeter) of the web.

[0011] In one embodiment, the web includes a recessed region in which the structural member is offset in a direction into the channel. In that embodiment, the C-shaped cross-section has a centroid and the centroid is within 0.125 inch (0.3175 centimeter) of the recessed region.

[0012] In one embodiment, the recessed region is at least 30% of an overall height of the structural member.

[0013] In one embodiment, the recessed region is in a range of 30% to 70% of an overall height of the structural member.

[0014] In one embodiment, the recessed region is about 70% of an overall height of the structural member.

[0015] According to one aspect of the invention, a shelving unit includes a plurality of posts, a plurality of shelf support beams of any one of the embodiments identified above configured to be attached to two posts of the plurality of posts, and the shelf is configured to be supported on the shelf support beam after the shelf support beam is coupled to the two posts.

[0016] In an alternative embodiment, a shelf support beam for use in a shelving unit to support a shelf includes a structural member having a C-shaped cross-section. In the cross-section, a web separates a top flange that is configured to support the shelf from a bottom flange. The web, the top flange, and the bottom flange define a channel. The C-shaped cross-section has a moment of inertia greater than 0.0613.

[0017] In one embodiment, the moment of inertia is at least 0.0617.

[0018] In one embodiment, the top flange includes a cap portion and a shelf support portion separated by a sidewall portion with the shelf support portion being configured to support the shelf and the sidewall portion being configured to prevent lateral movement of the shelf toward the web.

[0019] According to one aspect of the invention, there is a method of manufacturing the shelf support beam of any one of the embodiments identified above.

[0020] In one embodiment, the channel, the top flange, and the bottom flange define a cavity height, a top flange width, and a bottom flange width, respectively, and wherein a ratio of the cavity height to a sum of the top flange width and the bottom flange width is greater than 1.707.

[0021] In one embodiment, the ratio is at least 1.8.

[0022] In one embodiment, the cavity height is greater than 1.640 inches

(4.166 centimeters).

[0023] In an embodiment, a shelving unit includes a plurality of posts, a plurality of shelf support beams of any one of the embodiments above configured to be attached to two posts of the plurality of posts, and the shelf is configured to be supported on the shelf support beam after the shelf support beam is coupled to the two posts.

Brief Description of the Drawings

[0024] Various additional features and advantages of the invention will become more apparent to those of ordinary skill in the art upon review of the following detailed description of one or more illustrative embodiments taken in conjunction with the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the detailed description given below, serve to explain the one or more embodiments of the invention.

[0025] Fig. 1 is an isometric view of an exemplary shelving unit in

accordance with an embodiment of the invention;

[0026] Fig. 2 is a perspective view of a shelf support beam;

[0027] Figs. 3A and 3B are cross-sectional views of a shelf support beam of Fig. 2 taken along line 3A-3A;

[0028] Fig. 4 is an isometric cross-sectional detail view taken along line 4-4 of Fig. 2 showing a portion of one embodiment of the invention;

[0029] Fig. 5 is a perspective view of a shelf support beam according to one embodiment of the invention;

[0030] Fig. 6 is a cross-sectional view of the shelf support beam of Fig. 5 taken along section line 6-6;

[0031] Fig. 7 is an isometric cross-sectional detail view taken along line 7-7 of Fig. 5 showing a portion of one embodiment of the invention.

Detailed Description

[0032] To these and other ends, in one embodiment and with reference to Fig. 1 , a shelving unit 10 includes four corner posts 12 arranged in a generally rectangular configuration. A front pair of corner posts 12 cooperate to carry a front horizontal shelf support beam 14, and a rear pair of corner posts 12 cooperate to carry a rear horizontal shelf support beam 14. As is described in detail below, one or both of the front and rear shelf support beams 14 is configured to carry a substantially higher load than existing support beams. Applicant discovered that deflection of the shelf support beam 14 is minimized (i.e. , load carrying capacity maximized) when a moment of inertia for the beam 14 is maximized. Thus, according to embodiments of the present invention horizontal shelf support beams have increased moments of inertia relative to existing horizontal shelf support beams.

[0033] With continued reference to Fig. 1 , one or more side beams 18 couple each front corner post 12 with a corresponding rear corner post 12. Although not shown, corner posts 12 can carry side rails and/or a diagonal brace to increase the lateral stability of the shelving unit 10. In this

configuration, horizontal shelf support beams 14 would form an outer rim at one level of the shelving unit 10 and so extend between each post 12. By way of example only, horizontal shelf support beams are shown and described in commonly owned U.S. Application No. 16/130,398, now U.S. Pub. No.

2019/0125077, published May 2, 2019, which is incorporated by reference herein in its entirety.

[0034] The horizontal shelf support beams 14 are configured to support a shelf 22. Items (not shown) may be stored on the shelf 22 in the normal course of using the shelving unit 10. These items produce a load due to gravity on each of the support beams 14, which is transferred to the posts 12. One or more of the shelves 22 of the shelving unit 10, and preferably each of the shelves 22 of the shelving unit 10, may be configured as a wire rack (as shown).

[0035] In an exemplary embodiment, the horizontal shelf support beams 14 are configured to be selectively coupled to the posts 12 via releasable fastening means fully described in U.S. Application No. 16/130,398. By way of example, each of the horizontal shelf support beams 14 may include one or more locking pins 24 that are configured to be received within corresponding keyholes 26 that are distributed along the length of the corner posts 12. The horizontal shelf support beams 14 couple to the corner posts 12 at the keyholes 26 and may be moved vertically with respect to the posts 12 such that the number of horizontal shelf support beams 14 and their respective heights along the posts 12 may be varied. As shown, the shelving unit 10 includes four horizontal shelves 22 supported by shelf support beams 14 according to embodiments of the invention. However, it will be appreciated that any number of shelves 22 and corresponding horizontal shelf support beams 14 may be used.

[0036] As described above, according to aspects of the present invention, the horizontal shelf support beams 14 have increased load carrying capacity relative to existing support beams, can be produced with little or no additional material and so can be produced with existing materials and existing resources, and can be produced in conformity with existing manufacturing techniques. Thus, embodiments of the invention do not significantly add to the manufacturing cost of the shelving unit 10 while providing superior loading performance. To these and other ends, Applicants discovered that maximizing a moment of inertia of a cross-section of a beam will increase the load carrying capacity of the shelf support beam 14 relative to existing beams.

[0037] By way of comparison only and with reference to Figs. 2, 3A, 3B, and 4, an exemplary existing beam 28 is shown. The existing shelf support beam 28 is utilized in a shelving unit, such as that illustrated in Fig. 1. The existing shelf support beam 28 generally consists of a structural member 30 that is formed in a generally C-shape. Referring to Figs. 3A and 3B, for purposes of calculating a moment of inertia of the cross-section of the structural member 30, the cross-section of the shelf support beam 28 may be visually sectioned into section 32, section 34, and section 36. The section 32 separates section 34 from section 36 to define a channel 38 therebetween. Overall, the arrangement of the sections 32, 34, 36 defines the C-shape cross-sectional configuration of the structural member 30 and defines the channel 38.

[0038] In that C-shape cross-sectional configuration, section 32 includes a web 40, which forms a vertical portion of the structural member 30 during use. The section 34 defines a top flange 42 and is configured to receive a shelf. The top flange 42 extends generally inwardly in a shelving unit (e.g., Fig. 1 ) and in a direction away from the web 40. The top flange 42 has an L-shape portion 44 and a cap portion 46. The L-shape portion 44 includes a shelf support or lower portion 50 and a sidewall portion 52, and the cap portion 46 is rounded to transition from the web 40 to the sidewall portion 52 to define a top edge of the structural member 30. The sidewall portion 52 transitions from the cap portion 46 to the lower portion 50 to provide the L-shape configuration.

[0039] A shelf is supported on lower portion 50 with the sidewall 52 providing a stop for lateral movement of the shelf in an outward direction (i.e. , toward the web 40) in a shelving unit. A pair of existing shelf support beams 28 positioned on the front and rear sides of the shelf captures a shelf between opposing sidewalls 52 to prevent unwanted lateral movement of the shelf. Generally, a distance 64 between the top edge and the shelf support 50 is approximately a thickness of a shelf. Section 36 defines a bottom flange 48 that joins the web 40 on an opposite end of the web 40 from the top flange 42. As shown, the web 40 may be radiused at each of the locations at which the structural member 30 transitions to the top flange 42 and to the bottom flange 48.

Collectively, the top flange 42, the web 40, and the bottom flange 48 define the channel 38.

[0040] With reference to Fig. 3B, exemplary dimensions of the existing shelf support beam 28 are:

(1 ) a strip width of 3.656 inches (9.286 centimeters) (the strip width of the structural member 30 in the cross-section of Fig. 3A is the distance from one end 54 of the structural member 30 to the other end 56 along the structural member 30),

(2) a weight of approximately 2.6 pounds (approximately 1.179

kilograms),

(3) a cavity height (A1 ) (Fig. 3B) is the inside dimension between the top flange 42 at the lower portion 50 and the bottom flange 48 of 1.640 inches (4.166 centimeters),

(4) a gauge of 0.054 inch (0.1372 centimeter),

(5) a top flange width (A2) of 0.550 inch (1.397 centimeters) (as measured from the end 54 to the outwardly facing surface of the web 40),

(6) a bottom flange width (A3) of 0.411 inch (1.044 centimeters) (as measured from the end 56 to the outwardly facing surface of the web 40),

(7) a web height (A4) of 2.146 inches (5.451 centimeters),

(8) an overall height (A5) of 2.285 inches (5.804 centimeters), and

(9) a hardness of 12 on the Webster scale.

[0041] The moment of inertia for the shelf support beam 28 was calculated for each section 32, 34, and 36 of the beam 28 by determining a center of mass of the cross-section and then summing the moments of inertia for each section. For example, with reference to Figs. 3A and 3B, a center of mass (centroid) 60 is calculated. The center of mass (centroid) 60 establishes a neutral axis 62. The neutral axis 62 is generally perpendicular with a longitudinal axis 66 (Fig. 2) of the shelf support beam 28 though the two axes may not intersect. Individual moments of inertia, lx, are calculated for each of sections 32, 34, and 36 about the neutral axis 62 according to: where I c is the moment of inertia of the section 32 (i.e., I 32 ), the section 34 (i.e. , / 34 ), or the section 36 (i.e., / 36 ) about the section’s centroid, A is the area of the respective section 32, the section 34, or the section 36, and d is the vertical distance from the respective centroid (not shown) to the neutral axis 62 for each of the section 32, the section 34, or the section 36. Further, where sections 32, 34, 36 are approximated by rectangles then in which“b” corresponds to the base or width dimension of the rectangle and“h” corresponds to the height dimension of the rectangle.

[0042] Considering the sections 32, 34, and 36 as rectangles, and with reference to Fig. 3B, the section 32 is approximated by a rectangle having dimensions b1 by hi , section 34 is approximated by a rectangle b2 by h2 (which may be further sectioned into two rectangles, one horizontal and one vertical), and section 36 is approximated by a rectangle having dimensions b3 by h3. It will be appreciated that further sectioning, for example section 34, may improve the moment of inertia calculation for that section. Referring to Figs. 3A and 3B, the moment of inertia for the cross-section is calculated as the sum of the individual moments of inertia, lx, (see Table 1 ) of each section 32, 34, and 36 according to:

I total = hi + ^34+ he

Table 1

[0043] At a calculated moment of inertia of (0.0613), the theoretical capacity of the existing shelf support beam 28 is determined by finite elemental analysis to be 1070 pounds (485.3 kilograms). [0044] With reference now to Figs. 5, 6, and 7, in one embodiment of the invention, a shelf support beam 130 has a greater moment of inertia relative to the beam 28. The shelf support beam 130 is one embodiment of the shelf support beams 14 shown in Fig. 1. Further in that regard, the shelf support beam 130 generally consists of a structural member 132 that is formed in a generally C-shape and having a longitudinal axis 138. The exemplary shelf support beam 130 may be visually sectioned into three parts, i.e. , section 134, section 136, and section 140 (see Fig. 6) for a moment of inertia calculation with the procedure set out above with respect to the shelf support beam 28 of Figs. 2, 3A, 3B, and 4. The section 134 separates section 136 from section 140 and defines a channel 142. Overall, the arrangement of the sections 134, 136, and 140 defines a C-shape cross-sectional configuration.

[0045] In that C-shape cross-sectional configuration, section 134 includes a web 144, which forms a vertical portion of the structural member 132 during use. The section 134 defines a top flange 146 and is configured to receive the shelf 22. The top flange 146 extends generally inwardly in the shelving unit 10 (e.g., Fig. 1 ), and thus in a direction away from the web 144 and has an L- shape configuration. The top flange 146 has an L-shape portion 150 and a cap portion 152. The L-shape portion 150 includes a lower portion 154 and a sidewall portion 156, and the cap portion 152 is rounded to transition from the web 144 to the sidewall portion 156 to define a top edge of the structural member 132. The sidewall portion 156 transitions to the lower portion 154 to provide the L-shape configuration.

[0046] The shelf 22 is supported on lower portion 154 with the sidewall portion 156 providing a stop for lateral movement of the shelf 22 in an outward direction (i.e., toward the web 144) in the shelving unit 10. A pair of opposing shelf support beams 130 on opposing sides of the shelving unit 10 thus captures the shelf 22 between sidewall portions 156. Generally, a distance 160 between the top edge and the shelf support 154 is approximately a thickness of a shelf. Section 140 defines a bottom flange 162 that joins the web 144 on an opposite end of the web 144 from the top flange 146. As shown, the web 144 may be radiused at each of the locations at which the structural member 132 transitions to the top flange 146 and to the bottom flange 162. Collectively, the top flange 146, the web 144, and the bottom flange 162 define the channel 142 and a centroid 148, which is spaced apart from each of the top flange 146, the web 144, and the bottom flange 162. By way of example, the centroid 148 may be located within 0.125 inch (0.3175 centimeter) of the structural member 132.

[0047] As is best shown in Figs. 6 and 7, the web 144 includes a recessed region 164 that runs along substantially (e.g., 80% or more, 90% or more, and probably greater than 95%) the entire longitudinal length of the shelf support beam 130 as is shown in Fig. 5. Further, the recessed region 164 may be symmetrically positioned relative to the longitudinal length of the shelf support beam 130. That is, a midpoint of the recessed region 164 may be aligned with a midpoint of the longitudinal length of the shelf support beam 130. In the exemplary embodiment shown, the recessed region 164 is defined by a pair of outwardly facing sidewalls 166 and 170, which are angled relative to a plane 172 that defines an outer-most surface of the web 144. The opposing sidewalls 166 and 170 intersect a base surface 180.

[0048] While the recessed region 164 may decrease the overall height of the shelf support beam 130 (i.e. , relative to the shelf support beam 28 shown in Fig. 2-4 for an equivalent strip width), the recessed region 164 results in an offset 182 of the structural member 132 along a portion of the web 144 in the direction of the channel 142. This offset 182 increases the moment of inertia of the structural member 132 by a greater degree than any loss in the moment of inertia due to a decrease in overall height dimension of the web 144.

Embodiments of the present invention are not limited to the recessed region 164 extending the entire length of the shelf support beam 130. Furthermore, while a faceted recessed region 164 (i.e., defined by planar surfaces 166, 170, 180) is shown, the recessed region 164 may have other configurations, such as being rounded, or may have multiple other surfaces that define a portion of the web 144 that is offset from the plane 172 in a direction into the channel 142 and effectively decreasing the depth of the channel 142. In the embodiment shown in Fig. 6, the web 144 and the centroid 148 overlap at the recessed region 164 or the recessed region 164 may be within 0.125 inch (0.3175 centimeter) of the centroid 148.

[0049] With reference to Figs. 6 and 7, the recessed region 164 divides the web 144 into spaced apart outer portions at 174 and 176. The spaced apart outer portions 174 and 176 define the plane 172. In the exemplary embodiment, the base surface 180 is generally parallel to the plane 172 with each of the opposing sidewalls 166 and 170 having approximately the same dimensions and angles. With reference to Fig. 6, by way of example, the base surface 180 may be at least 20% of the overall height of the cross-section of the shelf support beam 130. By way of further example, the recessed region 164 may be more than 30% (such as in a range of 30% to 70%, and preferably in a range of 40% to 50%) of the overall height of the cross-section. The recessed region 164 may form about 70% of the overall height of the structural member 132.

[0050] With reference to Fig. 7, the recessed region 164 may appear to be symmetrical around a centerline of the recessed region 164. Flowever, embodiments of the present invention are not limited to a symmetrical recessed region 164. Moreover, the recessed region 164 need not be symmetrically positioned within the web 144. Although embodiments of the invention are not limited to the spacing shown, in Fig. 6, the recessed region 164 is offset relative to the top flange 146 and the bottom flange 162 as is indicated by arrow 178 with the recessed region 164 being positioned closer to the bottom flange 162. Advantageously, the shelf support beam 130 has a greater moment of inertia than the shelf support beam 28 shown in Figs. 2 and 3 as is set out below.

[0051] With reference to Fig. 6, dimensions of an exemplary shelf support beam 130 are:

(1 ) a strip width of 3.656 inches (9.286 centimeters) (the strip width of the structural member 132 in the cross-section of Fig. 6 is the distance from one end 184 of the structural member 132 to another end 186 along the structural member 132),

(2) a weight of approximately 2.6 pounds (approximately 1.179 kilograms),

(3) a cavity height (D1 ) (the inside dimension between the top flange 146 at the lower portion 154 and the bottom flange 162) of 1.715 inches (4.356 centimeters),

(4) a gauge of 0.054 inch (0.1372 centimeter),

(5) a top flange width (D2) of 0.567 inch (1.44 centimeters) (as measured from the end 184 to the inwardly facing surface of the web 144 at 174),

(6) a bottom flange width (D3) of 0.340 inch (0.8636 centimeter) (as measured from the end 186 to the inwardly facing surface of the web 144 at 176),

(7) a web height (D4) of 2.124 inches (5.395 centimeters),

(8) an overall height (D5) of 2.278 inches (5.786 centimeters),

(9) a hardness of 12 on the Webster scale,

(10) the base surface (D6) measures 0.671 inch (1.704 centimeters) with each of the opposing sidewalls measuring 0.133 inch (0.3378 centimeter), and

(11 ) the spaced apart portion (D7) is 0.566 inch (1.438 centimeters), and

(12) the spaced apart portion (D8) is 0.539 inch (1.369 centimeters).

[0052] The moment of inertia for the beam 130 is calculated for each section of the beam 130 by determining a centroid of each section and then summing the moments of inertia for each section as described above with respect to the shelf support beam 28.

Table 2

[0053] The moment of inertia of the cross-section of the shelf support beam 130 is at least 0.0617 and so is greater than 0.0613 (i.e. , the moment of inertia calculated for the cross-section of the beam shown in Fig. 3B). By way of example, the moment of inertia may be increased by about 0.5%. The theoretical capacity of the exemplary shelf support beam 130 is believed to be greater than the beam 28 shown in Fig. 2. For example, the theoretical capacity of the shelf support beam 130 may be at least 0.5% greater than the beam 28 and by way of further example may be about 9% greater than the beam 28.

[0054] As described above, the dimensions of the shelf support beam 130 are different than the shelf support beam 28 though the strip widths are the same. Despite being of equivalent strip widths, the different dimensions of the shelf support beam 130 with the recessed region 164 produce a greater moment of inertia than the moment of inertia of the shelf support beam 28.

[0055] By way of comparison, the overall height dimension of the shelf support beam 130 is less than the overall height dimension of the beam 28 by a small amount. In one embodiment, the overall height D5 of the shelf support beam 130 is about 2.278 inches (about 5.786 centimeters). However, the strip width remains the same at 3.656 inches (9.286 centimeters). For equivalent strip widths, the shelf support beam 130 shown in Figs. 5-7 has a greater load carrying capacity than the beam 28 of Figs. 2-4.

[0056] By way of further comparison, a cavity height D1 of the web 144 (Fig. 6) is greater than the cavity height A1 of the web 40 (Fig. 3B). However, the strip width remains the same for each of the shelf support beams 28 and 130. Even with an increase in cavity height, there may also be a reduction in the width dimensions of one or both flanges 146 and 162. In the exemplary embodiment, and by way of example only, the top flange 146 measures 0.567 inch (1.44 centimeters) as compared to the top flange 42 of the shelf support beam 28, which measures 0.550 inch (1.397 centimeters), and the bottom flange 162 measures 0.340 inch (0.8636 centimeter) as compared to the bottom flange 48, which measures 0.411 inch (1.044 centimeters). A ratio of the dimensions of the cavity height relative to the sum of the widths of the top flange and the bottom flange for the shelf support beam 130 shown in Figs. 5-7 is about 1.9 (see Fig. 6, e.g., dimension D1 of 1.715 inches (4.356 centimeters) to dimension D3 of 0.340 inch (0.8636 centimeter) plus dimension D2 of 0.567 inch (1.44 centimeters) (total of 0.907 inch (2.304 centimeters)) is 1.890).

According to one embodiment of the invention, the shelf support beam 130 has a ratio of cavity height to the sum of the flange widths of greater than 1.7. As another example, the ratio is greater than 1.8. The exemplary shelf support beam 28 has a ratio of cavity height (A1 ) to a sum of top and bottom flange widths (A2 and A3) of 1.707. Advantageously, the shelf support beam 130 may be produced from the same material stock as the shelf support beam 28 though the shelf support beam 130 is capable of carrying greater loads.

[0057] While the present invention has been illustrated by the description of various embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Thus, the various features discussed herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope of the general inventive concept.