BEST MODE FOR CARRYING OUT THE PRESENT INVENTION

[0022] Referring now to FIGS. 1-8 of the drawings, the improved structural strength equipment rack of the present invention is shown and generally designated 10. Equipment rack 10 is constructed from two upstanding frame members A joined by horizontal metal channel crossbar 12 at the top and a base or base weldment 14 at the bottom thereof to which a network bay base cover (as shown) or UFER base cover (not shown) may be attached by a suitable means such as screws (not shown).

[0023] In conventional equipment racks, the pair of upstanding spaced-apart frame members F typically utilize U-shaped channels having a cross-section as best shown in FIG. 1 of the drawings in order to form what is known in the trade as an unequal flange equipment rack. Upstanding frame member F shown in FIG. 1 typically includes a series of vertically spaced-apart apertures F′ in one flange and two series of vertically spaced-apart apertures F′ and F′ in the other flange thereof. The vertically spaced-apart apertures F′ in the back and front flanges of upstanding frame member F are used to mount selected telecommunications equipment between upstanding spaced-apart frame members F. It should be appreciated that although a network bay base is shown with equipment rack 10, the present invention contemplates that equipment rack 10 can also be a UFER base equipment rack of the type well known to those skilled in the art. Also, many other configurations of apertures can be provided in frame members F as a matter of design choice.

[0024] Referring again to improved equipment rack 10 best shown in FIGS. 4 and 5 of the drawings, it will be appreciated that the upstanding spaced-apart frame members of equipment rack 10 consist of hemmed flange frame member A as best seen in FIGS. 2-5 of the drawings in lieu of conventional U-shaped frame member F shown in FIG. 1 of the drawings. Hemmed flange upstanding frame member A shown in FIGS. 2-5 is formed from a flat sheet of steel (e.g., one-eighth inch thickness steel) that has been folded over onto itself on each side thereof so as to create a double thickness short or back flange BF and long or front flange FF. The hemmed flange upstanding frame member A as shown in FIG. 2 when utilized in equipment rack 10 provides for a stiffer equipment rack than the conventional pair of upstanding frame members F (see FIG. 1) utilized in prior art unequal flange equipment racks.

[0025] It has been discovered that improved equipment rack 10 of the present invention incorporating a pair of hemmed flange upstanding frame members A is approximately fourteen percent (14.0%) stiffer (e.g.,front-to-back stiffness) than conventional unequal flange equipment racks. Moreover, an additional advantage of incorporation of novel hemmed flange upstanding frame members A into equipment rack 10 is an increased horizontal space that is provided between the upstanding pair of frame members due to the positioning of apertures A′ closer to the plane of the inside wall Al of upstanding frame members A than can be accomplished with conventional unequal flange upstanding frame members F (see FIG. 1). This increased horizontal space can be used to better accommodate digital equipment in rack 10.

[0026] Referring now to FIG. 2 of the drawings to more specifically describe the structure of hemmed upstanding frame members A it can be seen that hemmed upstanding frame member A consists of a generally U-shaped cross-section comprising a web Al at the bottom with a relatively short side portion on one side and relatively long side portion on the other side wherein both the relatively short side portion and the relatively long side portion are bent back upon themselves so as to create relatively short hemmed flange side portion BF and relatively long hemmed flange side portion FF. The length of relatively short side portion BF that is bent back upon itself is parallel to the remaining length of relatively short side portion BF and the length of the relatively long side portion FF that is bent back upon itself as parallel to the remaining length of the relatively long side portion FF. Further, upstanding frame members A are formed from a generally U-shaped cross-section consisting of web Al along the bottom length and a first and second bend to form the relatively short side portion on one side that is then bent back upon itself at a third bend to create relatively short hemmed flange side portion BF and a first and second bend to form the relatively long side portion on the other side of the upstanding frame member that is then bent back upon itself at a third bend to create the relatively long hemmed flange side portion FF. Thus, upstanding frame members A (see FIG. 2) are formed of a sheet of steel (preferably ⅛ inch thick) having six bends and seven wall segments A1, A2, A3, A4, A5, A6, A7 to form unequal flange upstanding frame members A that impart the enhanced stiffness to the frame of equipment rack 10.

[0027] To better appreciate the ability of improved equipment rack 10 to provide increased horizontal space between upstanding frame members A due to the unique construction of upstanding frame members A, it should be understood that conventional unequal flange equipment racks formed from a pair of conventional upstanding frame members F (see FIG. 1) provide adequate mounting hole and upright spacing for conventional 21.5 inch and 17.5 inch wide telecommunications equipment. However, as is well known to those skilled in the telecommunications equipment rack art, as digital information transfer becomes more common in traditional central switching office environments, so does the requirement to house digital equipment in unequal flange telecommunications equipment racks. However digital equipment is often 0.25 inches wider (e.g., 21.75 inches and 17.75 wide) than previous telecommunications non-digital switching equipment, while maintaining the same equipment mounting hole distances of 22.312 inches and 18.312 inches. Thus, conventional equipment racks will many times not accommodate digital telecommunications equipment.

[0028] In order to accommodate digital telecommunications equipment, an equipment rack must provide the additional 0.25 inches in width while maintaining the mounting hole spacing the same as in conventional equipment racks. This can result in a problem since the tapped mounting holes F′ of the upright channels would have to be moved closer to the bend (see FIG. 1) at the inside front and rear corners of a conventional rack. However, due to material deformation caused by the local bending of the metal of the conventional upright channels F, the mounting holes or apertures F′ therein would tend to deform to such an extent as to be rendered unusable if moved closer to the bend. This problem is solved with improved equipment rack 10 of the present invention by utilizing upstanding frame members A which by virtue of their hemmed construction allow mounting holes or apertures A′ to be relatively closer to the inner wall Al of upstanding frame members A (see FIG. 2 of the drawings). Therefore, the mounting space between upstanding frame members A can be increased by the desired 0.25 inches in width to accommodate mounting of digital telecommunications equipment therebetween while the horizontal distance between mounting apertures A′ is maintained the same by laterally shifting of mounting apertures A′ inwardly toward the equipment side of hemmed upstanding frame members A.

[0029] Hemmed upstanding frame members A can be manufactured in a number of conventional techniques which would be known to those familiar with metal bending and formation. For example, the simplest way to create hemmed upstanding frame members A is to use a hemming dye in a large press brake which causes the metal to fold back onto itself and thereby create the desired hem at the front and back side of the upstanding frame members. The hemmed upstanding frame members can also be manufactured by stamping using a set of progressive dies to create the hemmed profile of upstanding frame members A. A third technique to achieve the desired shape is by roll-forming the hem at the front and back of upstanding frame members A by utilizing a series of rolls along the length of the elements.

[0030] It should be appreciated that the present invention contemplates the use of at least one and preferably a pair of upstanding hemmed frame members in a telecommunications equipment rack of either the UFER or network bay type. Also, the invention further contemplates the use of at least one and preferably a pair of the hemmed upstanding frame members not only in unequal flange-type equipment racks but in any type of telecommunications equipment rack into which they may be incorporated for enhanced structural strength.

[0031] Alternative Embodiments

[0032] Referring now to FIGS. 6-8 of the drawings, three (3) alternative embodiments of the upstanding frame members A utilized in the improved equipment rack 10 of the present invention are shown and generally designated AA, AAA, AAAA, respectively. At least one upstanding frame member AA, AAA, AAAA and preferably a pair would be used in equipment rack 10.

[0033] Frame member AA shown in FIG. 6 comprises a generally U-shaped four bend and five wall segment AA1, AA2, AA3, AA4, AA5 cross-section comprising a web AA1 having a bottom length and a first bend to form the relatively short side portion on one side that is then bent back upon itself to create the relatively short hemmed flange side portion and having a first bend to form the relatively long side portion on the other side of the frame member that is then bent back upon itself to create the relatively long hemmed flange side portion of the frame member. Frame member AA provides many of the benefits of frame member F shown in FIG. 1 and should be easier to manufacture.

[0034] Upstanding frame member AA shown in FIG. 6 comprising four bends and five wall segments also includes a vertical series of spaced-apart apertures AA′ formed in the front flange thereof. As with respect to frame member A, one or more vertical series of spaced-apart apertures would also normally be included in the back flange of frame member AA.

[0035] A third embodiment of upstanding frame members A utilized in improved equipment rack 10 of the present invention is shown and generally designated AAA in FIG. 7 of the drawings. Frame member AAA comprises a generally U-shaped four bend and five wall segment AAA1, AAA2, AAA3, AAA4, AAA5 cross-section comprising a web AAAM having a bottom length and a first bend to form one side portion that is then bent back upon itself to create one hemmed flange side portion and having a first bend to form the second side portion on the other side of the frame member that is then bent back upon itself to create the second hemmed flange side portion of frame member AAA. The front and back hemmed flanges of frame member AAA are of equal length as can best be seen with reference to FIG. 7.

[0036] Finally, a fourth embodiment of the upstanding frame members A utilized in improved equipment rack 10 of the present invention is shown and generally designated AAAA in FIG. 8. Frame member AAAA comprises a generally U-shaped five bend and six wall segment AAAA1, AAAA2, AAAA3, AAAA4, AAAA5, AAAA6 cross-section comprising web AAAA1 having a bottom length and a first and second bend to form the relatively short side portion on one side that is then bent back upon itself to create a relatively short hemmed flange side portion and having a first bend to form the relatively long side portion on the other side of frame member AAAA that is then bent normally thereto to create the relatively long non-hemmed flange side portion of frame member AAAA. Thus, frame member AAAA is formed with only one flange hemmed and the other flange formed similarly to the long flange of conventional frame member F shown in FIG. 1. It is presently contemplated that frame member AAAA will only be provided with apertures AAAA′ in the hemmed flange thereof.

[0037] It should be appreciated that while the four embodiments of the hemmed upstanding frame members utilized in improved equipment rack 10 of the present invention are shown in FIGS. 2-8 of the drawings with specific aperture mounting holes or apertures therein, the placement of apertures in each of the four embodiments of the upstanding frame members can be varied from that depicted in the drawings which are intended as representative only and not to limit the scope of the invention which is defined by the claims appended hereto.

[0038] Partially-Hemmed Embodiment

[0039] Also, a partially hemmed upstanding frame member A utilized in improved equipment rack 10 of the present invention is shown and generally designated PA in FIG. 9 of the drawings. Unlike the four embodiments of the invention described heretofore in FIGS. 2-8 of the drawings, frame member PA comprises only a partially hemmed back flange BF and front flange FF.

[0040] Frame member PA shown in FIG. 9 comprises a generally U-shaped four bend and five wall segment PA1, PA2, PA3, PA4, PA5 cross-section comprising a web PA1 having a bottom length and a first bend to form the relatively short side portion on one side that is then bent back upon itself at an acute angle to create the relatively short side portion (comprising PA2, PA3) and having a first bend to form the relatively long side portion on the other side of frame member PA that is then bent back upon itself at an acute angle to create the relatively long side portion (comprising PA4, PA5) of the frame member. The lengths of the relatively short and relatively long side portions bent back upon themselves each forms an acute angle of between about 15 to 45 degrees to the remaining lengths of the relatively short and relatively long side portions, respectively, and the bent back lengths PA3, PA5 each extend in a plane parallel to the other as seen with reference to FIG. 9. Preferably the acute angle between walls PA4, PA5 is about 15 degrees and between walls PA2. PA3 is about 45 degrees.

[0041] Frame member PA provides many of the same benefits as do frame members AA, AAA, AAAA, respectively, but should be generally easier to manufacture. Specifically, upstanding frame member PA can be manufactured using more conventional manufacturing techniques than those described herein for forming hemmed upstanding frame members M A, A, AAAA, respectively.

[0042] Upstanding frame member PA shown in FIG. 9 comprising four bends and five wall segments also includes a vertical series of spaced-apart apertures PA′ formed in the front flange FF and/or back flange BF thereof as a matter of design choice. Further, at least one upstanding frame member PA, and preferably two would be used in the manufacture of equipment rack 10.

[0043] It will be understood that various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation—the invention being defined by the claims.