US20060043031A1

US20060043031A1 - Electronic equipment rack

Info

Publication number: US20060043031A1
Application number: US11/201,475
Authority: US
Inventors: Eric Rinderer
Original assignee: Cooper Technologies Co
Current assignee: Cooper Technologies Co
Priority date: 2004-08-26
Filing date: 2005-08-11
Publication date: 2006-03-02

Abstract

A two-post electronic equipment rack of this invention is adapted for holding telecommunication equipment and the like. The rack comprises a structural frame including a base and a pair of posts secured to the base and extending up from the base adjacent opposite sides of the base. Each of the posts comprises substantially vertical front and back tubular frame members having a centerline spacing of less than about twelve in. The structural frame also includes a plurality of cross braces connecting the front and back tubular frame members of each of the two posts. A plurality of substantially vertical equipment mounting rails not constituting part of the structural frame are attached to the structural frame for mounting the equipment on the rack.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to electronic equipment racks, and particularly to such racks that are adapted to withstand seismic events.
Racks for holding electronic equipment, such as telecommunications equipment, come in various configurations. Some racks, referred to as “two-post” racks, include a pair of upright posts, one at each side of the rack. Other racks, referred to as cabinets, include four upright posts, two toward the front of the rack at opposite sides of the rack and two toward the back of the rack at opposite sides of the rack. Typical cabinets have side panels extending between the front and back posts at opposite sides of the cabinet. Conventional two-post racks typically occupy less space but they are not as effective in withstanding seismic events absent substantial (and expensive) reinforcement. Cabinets, on the other hand, are generally more durable during seismic activity but consume large amounts of space, since the centerline spacing between the front and back posts is typically greater than 18 in. (e.g., 24-48 in.). There is a need, therefore, for an electronic equipment rack that is sufficiently strong to withstand seismic events yet relatively compact to conserve space.

SUMMARY OF THE INVENTION

Among the several objects of this invention may be noted the provision of an improved two-post electronic equipment rack for holding telecommunications equipment and the like; the provision of such a rack which, in at least one embodiment, is designed to withstand seismic events; the provision of such a rack which, in at least one embodiment, is relatively compact to preserve space; the provision of such a rack which, in at least one embodiment, is relatively lightweight (e.g., about 100 lbs) yet capable of holding a relatively heavy load of equipment (e.g., up to 1000 lbs); the provision of such a rack which, in at least one embodiment, is economical to manufacture; and the provision of such a rack which, in at least one embodiment, permits cable to be conveniently routed to and from the equipment on the rack.
In general, a two-post electronic equipment rack of this invention comprises a structural frame including a base and a pair of posts secured to the base and extending up from the base adjacent opposite sides of the base. Each of the posts comprises substantially vertical front and back tubular frame members having a centerline spacing of less than about twelve in. The structural frame further comprises a plurality of cross braces connecting the front and back tubular frame members of each of the two posts. A plurality of substantially vertical equipment mounting rails not constituting part of the structural frame are attached to the structural frame for mounting the equipment on the rack.
Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of one embodiment of a rack of this invention;
FIG. 2 is an enlarged view of the upper left-hand corner of the rack of FIG. 1;
FIG. 3 is a perspective of an upper portion of the rack adapted to hold a cable tray (shown in phantom lines);
FIG. 4 is a perspective of a lower portion of the rack;
FIG. 5 is an enlarged view of the lower left-hand corner of the rack of FIG. 4;
FIG. 6 is a view similar to FIG. 5 with the components used to secure the rack to the floor exploded;
FIG. 7 is a front view of a top portion of the rack, a cable tray supported by the rack being shown in phantom;
FIG. 8 is a perspective of a lower portion of a second embodiment of a rack having interior gussets; and
FIG. 9 is a front view of the rack;
FIG. 10 is an enlarged view of the upper left-hand corner of the rack of FIG. 9 showing weld locations;
FIG. 11 is an enlarged view of the lower left-hand corner of the rack of FIG. 9 showing weld locations;
FIG. 12 is a section taken along line 12-12 of FIG. 11 showing weld locations;
FIG. 13 is a side view of the rack;
FIG. 14 is an enlarged view showing weld locations on a tab of FIG. 13;
FIG. 15 is an enlarged view showing weld location on a cross brace shown in FIG. 13; and
FIG. 16 is an enlarged view showing weld location on a front gusset and on a back gusset shown in FIG. 15.
Corresponding parts are designated by corresponding reference numbers throughout the several views of the drawings.

DETAILED DESCRIPTION

Referring to FIG. 1 of the drawings, one embodiment of a two-post electronic equipment rack of this invention is designated in its entirety by the reference numeral 1. In general, the rack 1 comprises a structural frame, generally indicated at 3, and a plurality of non-structural substantially vertical equipment mounting rails, each designated 5, attached to the structural frame for mounting electronic equipment 9 on the rack. The electronic equipment 9 illustrated in FIG. 1 is telecommunications equipment (e.g., patch panels), but it will be understood that the rack 1 is suitable for mounting other types of equipment as well.
The structural frame 3 includes a base, generally designated 11, and a pair of left and right posts, each generally designated 15, secured to the base and extending up from the base adjacent opposite sides of the base. Each of the posts 15 comprises front and back substantially vertical tubular frame members 15F, 15B. As used herein, a frame member 15F, 15B is “substantially vertical” if it is oriented at an angle of up to about twenty degrees off vertical, it being understood that it may be desirable under some circumstances to angle one or both frame members 15F, 15B relative to one another so they converge in an upward direction. The front and back tubular frame members 15F, 15B are said to comprise a single “post” because the centerline spacing S between the two frame members is relatively close, i.e., less than about 12 in (FIG. 2). By way of example, the centerline spacing S may be about 8 in., although this dimension may vary. In the illustrated embodiments, the tubular frame members 15F, 15B are generally rectangular in cross section, but other cross sections are possible (e.g., circular, square, triangular). Further, the tubular frame members 15F, 15B may be formed with or without longitudinal seams. In general, the tubular frame members 15F, 15B of a rack 1 of this invention are more effective than open structural shapes such as angle, channel or Z-shaped frame members in resisting torsional and compressive forces, for example.
With particular reference to FIG. 3, the structural frame 3 also includes a substantially horizontal front top frame member 17F connecting upper ends of the front tubular frame members 15F and a substantially horizontal back top frame member 17B connecting upper ends of the back tubular frame members 15B. In one embodiment these frame members 17F, 17B are angle bars each having a vertical leg 19 secured to respective front and back faces of the front and back tubular frame members 15F, 15B, and a horizontal leg 21 with fastener openings 23 for securing additional structure to the frame 3 of the rack 1. Other configurations are possible.
The structural frame 3 further comprises a plurality of cross braces 25 connecting the front and back tubular frame members 15F, 15B of each post 15 (FIG. 1). In the illustrated embodiment, the tubular frame members 15F, 15B of each post 15 are connected by four such cross braces 25, a lower brace adjacent the base 11, an upper brace adjacent the upper ends of the frame members 15F, 15B, and two braces spaced at intervals between the upper and lower braces. It will be understood that the number of braces 25 may vary. Each brace 25 may be generally channel-shaped, with a relatively wide central web 27 and narrow upper and lower flanges 29 extending from the web (FIG. 2). Other configurations are possible. For enhanced stability, each cross brace 25 desirably has a vertical dimension or height D1 greater than at least about 0.5 times the horizontal distance D2 between respective front and back tubular frame members 15F, 15B, more desirably greater than at least about 0.75 times the horizontal distance D2, and even more desirably greater than at least about 0.80 times the horizontal distance D2. By way of example, where D2 is 12 in., D1 may be 9.6 in, and where D2 is 4.0 in., D1 may be 3.2 in. The cross braces 25 have openings 31 therein, e.g., horizontal rows of fastener holes, the function of which will become apparent.
Referring again to FIG. 3, the upper cross braces 25 at opposite sides of the frame 3 are spaced below the upper ends of the front and back tubular frame members 15F, 15B for defining, in combination with the front and back top frame members 17F, 17B, a channel space 33 sized to receive cable or a cable tray 35 for holding cable extending across the rack at a level at or below a top of the rack 1. By way of example, a wire basket-type cable tray 35 is shown in phantom. Other types of cable tray may be used.
With reference to FIGS. 4-6, the base 11 comprises a front base frame member 37F connecting lower ends of the front tubular frame members 15F, and a back base frame member 37B connecting lower ends of the back tubular frame members 15B. In the illustrated embodiment, each of these base frame members 37F, 37B comprises a substantially vertical upper leg 39 having opposite ends which overlap and are secured to respective tubular frame members 15F, 15B, as by welding, and a substantially horizontal lower leg 41 extending from the lower edge of the upper leg in a direction away from the center of the rack 1. A horizontal flange 43 extends from the upper edge of the vertical leg 39 in a direction opposite the lower leg 41, i.e., toward the center of the rack. The horizontal flanges 43 have lengths generally corresponding to the side-to-side spacing between the tubular frame members 15F, 15B, so that the ends of the flanges are closely adjacent respective tubular members. In one embodiment, each base frame member 37F, 37B is formed from a single piece of sheet metal bent into the desired shape, but the frame member may be fabricated from multiple pieces. Other shapes are possible as well. The area between the vertical legs 39 of the front and back base frame members 37F, 37B is substantially open (i.e., the rack has no bottom or a largely open bottom between the front and back base frame members) so that cable may be routed to and from the equipment 9 through this open area at the lower end of the rack 1. Holes 45 are also provided in one or both of the vertical legs 39 of the base frame members 37F, 37B for installation of electrical devices (e.g., outlets).
The base 11 also includes a pair of side gussets 47 at opposite sides of the rack connecting respective front and back tubular frame members 15F, 15B. In one embodiment, the side gussets 47 have quadrilateral upright plate portions 49 attached (e.g., welded) to respective front and back tubular frame members 15F, 15B and rectangular lower plate portions 51 underlying the lower legs 41 of the front and back base frame members 37F, 37B. Horizontal flanges 53 are provided along the upper edges of the upright plate portions 49 of the gussets 47. As best illustrated in FIGS. 5 and 6, these flanges 53 have lengths generally corresponding to the spacing between the front and back tubular frame members 15F, 15B and depths (widths) such that the flanges terminate at or close to the webs 27 of respective lower cross braces 25. Holes 55 are provided in the upright plate portions 49 of the gussets 47 for routing cable to and from the equipment 9 on the rack 1.
The base 11 also includes washers 58 and reinforcing slabs 57 (e.g., 0.5 in. thick metal slabs) overlying the lower legs 41 of respective base frame members 37F, 37B and the lower plate portions 51 of respective side gussets 47 (see FIG. 6). These washers 58, slabs 57, the lower legs 41 of the base frame members 37F, 37B and the lower plate portions 51 of the side gussets 47 have vertically aligned openings 59 therein for receiving fasteners 61 (e.g., bolts) for securing the rack 1 to a floor. The openings 59 in the washers are circular whereas the openings in the slabs 57, the lower legs 41 of the base frame members 37F, 37B and the lower plate portions 51 of the side gussets 47 are oblong. As a result, the bolts 61 and washers 58 are positionable at any location along the length of the oblong openings 59. Desirably, the distance between the center of one set of vertically aligned openings 59 and a respective adjacent tubular frame member 15F, 15B is relatively small (e.g., about 2 in.). By reducing the distance from the tubular frame members 15F, 15B to the bolts 61, less material thickness is required in the areas of the base between the bolts and respective frame members to withstand the forces exerted during a seismic event.
With reference to FIGS. 1 and 7, the mounting rails 5 for mounting the equipment 9 on the rack 1 are preferably movable independent of the frame 3 so that during a seismic event the rails are adapted to move (flex) at a harmonic frequency different from the harmonic frequency of the structural frame. This difference serves as a vibration damping system tending to reduce the overall amplitude and/or frequency of vibration of the rack during seismic activity, which decreases the risk of damage to and/or failure of the rack 1. Preferably, the configuration of the rack 1 should be such that the structural framework carrying a maximum equipment load has a natural harmonic frequency greater than the high-amplitude frequencies of a typical seismic event (e.g., about 15 Hz compared to less than 10 Hz). Also preferably, the equipment mounting rails 5 should have natural harmonic frequency different from (greater or less than) that of the structural framework of the rack 1 and greater than the high-amplitude frequencies of a seismic event. By way of example, the mounting rails 5 may have a natural harmonic frequency of about 12 Hz.
In one embodiment, the equipment mounting rails 5 comprise angle bars, each having a first vertical leg 63 extending in a side-to-side plane of the rack 1 and a second vertical leg 65 extending in a front-to-back plane of the rack (see FIG. 8). The first (side-to-side) legs 63 of the rails 5 have fastener openings 67 spaced at regular intervals along their lengths for attachment of electronic equipment 9 to the rails. By way of example, the openings 67 may be circular holes spaced at regular intervals (e.g., a series of holes which repeat at ⅝ in. −⅝ in. −½ in. intervals), or at intervals corresponding to a standard rack-mounting unit (RMU). The second (front-to-back) legs 65 of the rails 5 have fastener openings 69 spaced along their lengths which are adapted to align with selected openings 31 in the cross braces 25 for securement of the rails to the cross braces at desired positions by suitable fasteners 71 (FIG. 2). The positions of the equipment mounting rails 5 can be adjusted as needed simply by removing the fasteners 71, relocating the rails, and then refastening the rails to the cross braces 25.
Referring to FIGS. 1 and 14, tabs 72 are affixed to the front and back tubular frame members 15F, 15B at opposite sides of the rack 1. These tabs 72 are formed with apertures 74 which are vertically aligned with other apertures 74A in respective side gussets 47 of the rack for receiving fasteners to secure one or more wire management devices to the rack. The rack 1 may have any number of tabs 72 or other mounting elements. Alternatively, the tabs 72 may be eliminated altogether.
Optionally (FIG. 8), the base 11 further comprises a plurality of interior gussets 73 above the lower legs 41 of the base frame members 37F, 37B, each interior gusset 73 having a triangular upright portion 75 attached (e.g., welded) to a vertical leg 39 of a respective front or back base frame member 37F, 37B and a quadrilateral lower portion 77 overlying the lower leg of a respective base frame member. The lower portions 77 of the interior gussets 73 are sandwiched between the lower legs 41 of respective base frame members 37F, 37B and respective reinforcing slabs 57, and they are also positioned directly over the lower portions 51 of the side gussets 47, creating a type of “stirrup” arrangement for added strength. The lower portions 77 of the interior gussets 73 have oblong openings (not shown) therein vertically aligned with respective openings 59 in the slabs 57, in the washer 58, in the lower legs 41 of respective base frame member 37F, 37B, and in respective lower plate portions 51 of the side gussets 47 for receiving the aforesaid fasteners 61. The interior gussets 73 strengthen the rack 1 and are useful in situations where the rack is intended to carry more weight than the previous embodiment, e.g., 1000 lbs of equipment compared to 750 lbs.
The various components of the rack 1 may be secured together in suitable fashion. For example, certain components can be welded together as shown in FIGS. 9-16, the weld lines being indicated by xxxxx on FIGS. 10-12 and 14-16. The structural components of the rack frame 3 (e.g., frame members and base components) are preferably fabricated from relatively light gauge structural steel, e.g., metal tubing having a wall thickness of 0.075 in., and metal plate having a thickness of 0.135 in. for the base frame members 37F, 37B, gussets 47, 73 and top frame members 17F, 17B, and a thickness of 0.075 in. for the cross braces 25. As a result, the rack 1 is relatively lightweight (e.g., 100 lbs or less) even though very strong. The non-structural components of the rack 1 (e.g., the mounting rails 5) may be fabricated from angle bar stock having a thickness of 0.135 in. These thicknesses are illustrative only.
The rack 1 described above is strong and capable of withstanding seismic activity. Further, the rack 1 is compact and is open at its front, back, top, bottom and sides to permit routing of cable to and from the equipment 9 on the rack in virtually any direction. The rack 1 is also designed for convenient, compact installation of cable tray 35 adjacent the top of the rack.
Certain of the features described above (e.g., the channel space 33 in the top of the rack 1 for receiving cable tray 35) can be incorporated in non-seismic racks without departing from the scope of this invention.
When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.
As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

1. A two-post electronic equipment rack, comprising

a structural frame including a base and a pair of posts secured to the base and extending up from the base adjacent opposite sides of the base,

each of said posts comprising substantially vertical front and back tubular frame members having a centerline spacing of less than about twelve in.,

said structural frame further comprising a plurality of cross braces connecting the front and back tubular frame members of each of said posts, and

a plurality of non-structural substantially vertical equipment mounting rails attached to said structural frame for mounting said equipment on the rack.

2. A rack as set forth in claim 1 wherein said mounting rails are movable independent of the frame whereby during a seismic event the mounting rails are adapted to move at a harmonic frequency different from the harmonic frequency of said structural frame.

3. A rack as set forth in claim 1 wherein said structural frame also includes a substantially horizontal front top frame member connecting upper ends of the front tubular frame members and a substantially horizontal back top frame member connecting upper ends of the back tubular frame members, and wherein said plurality of cross braces include a pair of upper cross braces at opposite sides of the frame spaced below the upper ends of the front and back tubular members for defining, in combination with said front and back top frame members, a space sized and configured to receive cable or a cable tray for holding cable extending across the rack at a level at or below a top of the rack.

4. A rack as set forth in claim 1 wherein the rack has open sides, an open front and an open back to permit routing of cable to and from said equipment through said open sides, said open front and said open back.

5. A rack as set forth in claim 4 wherein the rack has an open top and an open bottom to permit routing of cable to and from said equipment through said open top and bottom.

6. A rack as set forth in claim 1 wherein said base comprises a front base frame member connecting lower ends of the front tubular frame members, a back base frame member connecting lower ends of the back tubular frame members, and a pair of side gussets connecting respective front and back tubular frame members, said side gussets having upright plate portions attached to respective front and back tubular frame members and lower plate portions underlying respective front and back base frame members.

7. A rack as set forth in claim 6 further comprising reinforcing slabs overlying respective base frame members and respective lower plate portions of the side gussets, said slabs, base frame members and respective lower plate portions of the side gussets having vertically aligned openings therein for receiving fasteners for securing the rack to a floor.

8. A rack as set forth in claim 7 wherein the distance between a center of one set of said vertically aligned openings and a respective tubular frame member is about 2 in.

9. A rack as set forth in claim 7 wherein said base further comprises a plurality of interior gussets above respective base frame members, each interior gusset having an upright portion attached to a vertical leg of a respective front or back base frame member and a lower portion overlying a lower leg of a respective front or back base frame member.

10. A rack as set forth in claim 9 wherein the lower portions of said interior gussets are sandwiched between the lower legs of respective base frame members and respective reinforcing slabs, and wherein said lower portions of said interior gussets have openings therein vertically aligned with openings in respective slabs, respective lower legs of the base frame members, and lower plate portions of respective side gussets for receiving said fasteners.

11. A rack as set forth in claim 1 wherein said cross braces have a vertical dimension greater than at least about 0.5 times the horizontal distance between respective front and back tubular frame members.

12. A rack as set forth in claim 1 wherein said tubular frame members are generally rectangular in cross section, and wherein said mounting rails comprise vertical angle bars secured to said cross braces.