CA2235657A1 - Seismic resistant equipment rack - Google Patents
Seismic resistant equipment rack Download PDFInfo
- Publication number
- CA2235657A1 CA2235657A1 CA 2235657 CA2235657A CA2235657A1 CA 2235657 A1 CA2235657 A1 CA 2235657A1 CA 2235657 CA2235657 CA 2235657 CA 2235657 A CA2235657 A CA 2235657A CA 2235657 A1 CA2235657 A1 CA 2235657A1
- Authority
- CA
- Canada
- Prior art keywords
- uprights
- rack
- pair
- plates
- welded
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/02—Constructional details
- H04Q1/10—Exchange station construction
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/02—Constructional details
- H04Q1/09—Frames or mounting racks not otherwise provided for
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/02—Constructional details
- H04Q1/11—Protection against environment
- H04Q1/112—Protection against environment mechanical protection, e.g. resistance to earthquakes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q2201/00—Constructional details of selecting arrangements
- H04Q2201/02—Details of frames
Abstract
A seismic resistant equipment rack which has a pair of hollow tubular uprights having a rectangular cross section and a hollow tubular cross member extending across the top of the uprights from one of the pair to another and welded to the uprights around a perimeter of each end of the cross member. A stiffening device is mounted in each of the uprights proximate a top thereof for stiffening the top of the rack. A pair of gusset plates extends from a base of one of the uprights to another. The gusset plates are welded to the uprights along a top and bottom thereof. A pair of stiffening elements are welded at each side of the rack to each of the gusset plates and extend transversely to the plates.
Description
CA 0223~6~7 1998-04-24 SEISMIC RESISTANT EQUIPMENT RACK
FIELD
The present invention relates to an equipment rack typically used for telephone relays which have been made resistant to damage from seismic 5 disturbances.
BACKGROUND
Telephone companies typically have several sites around a major metropolitan area where racks of relays are stored together with other 10 equipment. The purpose of these sites known as central offices, is to operate as switching centers for telecommunication within a region of subscribers. The relays located at these sites are critically important to the maintenance of telephone communications within the area and with other areas. One of the main potential causes of damage is due to seismic disturbances, particularly in 15 regions of high earthquake activity. In such areas as well as other areas it is important to design racks for holding these relays which are resistant to damagefrom seismic disturbances. Typically such racks have been made from aluminum formed into a rectangular frame with a cross bar at the top and bolted and/or welded to a common base. Dynamic testing of such racks has disclosed 20 them to be unable to withstand even relatively small earthquakes when subjected to lateral vibrations. Often the upstanding frame elements twisted dramatically.
Known telephone racks include that disclosed in U.S. Patent No.
25 4,715,502 issued to Salmon. The Salmon rack is made up of a pair of U-shaped upright members joined at the top by a U-shaped cross member and bolted at the bottom to base plates transverse to the plane defined by the upright and cross members. The base plates are described as the means by which the upright members are prevented from tilting forward or backwards.
30 The U-shaped channels are inherently stronger than a flat plate but not CA 0223~6~7 1998-04-24 sufficiently strong to prevent twisting and/or bending when strong seismic forces are imposed.
U.S. Patent No. 5,566,836 issued to Lerman also discloses a 5 telecommunication rack having a pair of U-shaped channel uprights joined at the bottom by plates extending across the bottom of the uprights and bolted to the latter with the ends bent transverse to the plates so as to provide some stiffening to the plates. It is doubtful that the base bolts which affix the uprights to the base plates or the U-shaped uprights could withstand any significant 10 seismic activity.
U.S. Patent No. 4,493,422 issued to Kaegebein discloses a rack having a pair of U-shaped channel members as uprights, a U-shaped cross member and a pair of base plates the extend transversely to the plane defined 15 by the uprights and cross member and a pair of oppositely disposed stiffening members affixed to each base plate and associated upright. Kaegebein discloses no cross member joining the base of the uprights. Although the stiffening members would assist in resisting vibrations transverse to the plane of the uprights and cross member, the bolts between the base plate and the 20 stiffeners would be subject to shear. Also horizontal vibration forces parallel to the latter plane would be resisted only by the bolts between the stiffeners and the base of the uprights. The latter bolts are also in shear.
Accordingly, it is an object to provide an improved rack for holding 25 equipment that provides improved resistance to seismic vibrations.
SUMMARY OF THE INVENTION
According to the invention there is provided a seismic resistant equipment rack which has a pair of hollow tubular uprights having a rectangular 3 o cross section and a hollow tubular cross member extending across the top of the uprights from one of the pair to another and welded to the uprights around a CA 0223~6~7 l998-04-24 perimeter of each end of the cross member. A stiffening device is mounted in each of the uprights proximate a top thereof for stiffening the top of the rack. A
pair of gusset plates extends from a base of one of the uprights to another. Thegusset plates are welded to the uprights along a top and bottom thereof. A pair 5 of stiffening elements are welded at each side of the rack to each of the gusset plates and extend transversely to the plates. The above rack is simpler than known racks, much lighter and less expensive. Utilizing gusset plates together with stiffeners for the gusset plates and welding the uprights to the gusset plates provides hitherto unachieved stability. Added to this is the strength of 10 rectangular tubular steel frame members and cross members.
A pair of stiffening plates may be aligned with top and bottom surfaces of the cross member and welded in an interior of each of the uprights proximate a top thereof. The stiffening plates provide continuity of material from 15 an outside surface on one side of the rack to an outside surface of the other side. This makes any deformation of the upper end of the rack much more difficult.
The tubular uprights and cross bar are preferably made of steel.
FIELD
The present invention relates to an equipment rack typically used for telephone relays which have been made resistant to damage from seismic 5 disturbances.
BACKGROUND
Telephone companies typically have several sites around a major metropolitan area where racks of relays are stored together with other 10 equipment. The purpose of these sites known as central offices, is to operate as switching centers for telecommunication within a region of subscribers. The relays located at these sites are critically important to the maintenance of telephone communications within the area and with other areas. One of the main potential causes of damage is due to seismic disturbances, particularly in 15 regions of high earthquake activity. In such areas as well as other areas it is important to design racks for holding these relays which are resistant to damagefrom seismic disturbances. Typically such racks have been made from aluminum formed into a rectangular frame with a cross bar at the top and bolted and/or welded to a common base. Dynamic testing of such racks has disclosed 20 them to be unable to withstand even relatively small earthquakes when subjected to lateral vibrations. Often the upstanding frame elements twisted dramatically.
Known telephone racks include that disclosed in U.S. Patent No.
25 4,715,502 issued to Salmon. The Salmon rack is made up of a pair of U-shaped upright members joined at the top by a U-shaped cross member and bolted at the bottom to base plates transverse to the plane defined by the upright and cross members. The base plates are described as the means by which the upright members are prevented from tilting forward or backwards.
30 The U-shaped channels are inherently stronger than a flat plate but not CA 0223~6~7 1998-04-24 sufficiently strong to prevent twisting and/or bending when strong seismic forces are imposed.
U.S. Patent No. 5,566,836 issued to Lerman also discloses a 5 telecommunication rack having a pair of U-shaped channel uprights joined at the bottom by plates extending across the bottom of the uprights and bolted to the latter with the ends bent transverse to the plates so as to provide some stiffening to the plates. It is doubtful that the base bolts which affix the uprights to the base plates or the U-shaped uprights could withstand any significant 10 seismic activity.
U.S. Patent No. 4,493,422 issued to Kaegebein discloses a rack having a pair of U-shaped channel members as uprights, a U-shaped cross member and a pair of base plates the extend transversely to the plane defined 15 by the uprights and cross member and a pair of oppositely disposed stiffening members affixed to each base plate and associated upright. Kaegebein discloses no cross member joining the base of the uprights. Although the stiffening members would assist in resisting vibrations transverse to the plane of the uprights and cross member, the bolts between the base plate and the 20 stiffeners would be subject to shear. Also horizontal vibration forces parallel to the latter plane would be resisted only by the bolts between the stiffeners and the base of the uprights. The latter bolts are also in shear.
Accordingly, it is an object to provide an improved rack for holding 25 equipment that provides improved resistance to seismic vibrations.
SUMMARY OF THE INVENTION
According to the invention there is provided a seismic resistant equipment rack which has a pair of hollow tubular uprights having a rectangular 3 o cross section and a hollow tubular cross member extending across the top of the uprights from one of the pair to another and welded to the uprights around a CA 0223~6~7 l998-04-24 perimeter of each end of the cross member. A stiffening device is mounted in each of the uprights proximate a top thereof for stiffening the top of the rack. A
pair of gusset plates extends from a base of one of the uprights to another. Thegusset plates are welded to the uprights along a top and bottom thereof. A pair 5 of stiffening elements are welded at each side of the rack to each of the gusset plates and extend transversely to the plates. The above rack is simpler than known racks, much lighter and less expensive. Utilizing gusset plates together with stiffeners for the gusset plates and welding the uprights to the gusset plates provides hitherto unachieved stability. Added to this is the strength of 10 rectangular tubular steel frame members and cross members.
A pair of stiffening plates may be aligned with top and bottom surfaces of the cross member and welded in an interior of each of the uprights proximate a top thereof. The stiffening plates provide continuity of material from 15 an outside surface on one side of the rack to an outside surface of the other side. This makes any deformation of the upper end of the rack much more difficult.
The tubular uprights and cross bar are preferably made of steel.
2 0 However, other metal alloys which are as strong or stronger than steel may be used.
The uprights may have a cross section with dimensions of 2 inches by 4 inches by 1/8 inch. The gusset plate may be 1/2 inch thick and also 25 may be made of steel.
Advantageously, the natural frequency of the rack in either a direction parallel to a plane of the uprights or transverse thereto preferably exceeds 6 Hertz.
CA 0223~6~7 1998-04-24 BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages will be apparent from the following detailed description, given by way of example, of a preferred embodiment taken in conjunction with the accompanying drawings, wherein:
Fig. 1 is a perspective view of the seismic resistant equipment rack;
Fig. 2 is a front elevation view of the equipment rack;
Fig. 3 is a detail diagram of an upper corner of the rack;
Fig. 4 is a partial section of the upper corner of the rack; and Fig. 5 is a side elevation view of a bottom portion of the rack.
DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS
Referring to Figures 1 and 2 the equipment rack 10 has two upright parallel tubular members 12 and 14 of rectangular cross section.
These uprights are 4 inch by 2 inch by 1/8 inch hollow structural steel sections.
Metal such as aluminum is too soft to provide sufficient strength. A cross member 18 joins upright members 12 and 14 at the top and is welded around the perimeter of the ends of cross bar 18. The cross member 18 is of the same cross sectional dimensions and the same material as uprights 12 and 14. In addition, as seen in Figures 3 and 4 two stiffening plates 30 and 32 are positioned to align with the top and bottom surfaces of cross bar 32 when the latter is in position to be welded to the uprights. The stiffening plates 30 and 32 have welds 34 and 36, respectively, extending around their perimeter which bond them to the inside of the respective uprights 12 and 14. Thus, there is a 3 o continuity of material all across the top through to the outside surfaces of uprights 12 and 14.
CA 0223~6~7 l998-04-24 The bottom of the two uprights 12 and 14 are welded to two right angle 1/2 inch thick steel gusset plates 16 and 26 with welds 44 and 42 formed along the top and bottom, respectively, of each plate at each upright 12 and 14 and by welds 41 and 43 along the sides of each upright at each of plates 16 and 26. In addition, steel stiffeners 20 are welded at each end on each side of the rack 10. The stiffeners 20 have welds 41 and 43 along each side of their line of contact with the plates 16 and 26. They provide resistanceto vibrational motion perpendicular to the plane of the rack. Welds 44 and 42 10 of the plates 16 and 26 to the bottom of the uprights 12 and 14 serve to resist shear due to vibrations in the plane of the rack 10. The bottom portion 24 of base plates 26 and 16 is anchored to a base support (not shown) which is usually a thick reinforced concrete slab. Heavy plate washers 38 and seismically rated anchors 40 are used to fasten the rack base to a concrete 15 floor through slots 22.
Utilizing strong steel members of rectangular cross section improves the resistance of the rack to fracture of these members and twisting.
Ordinarily, shelving and equipment is screwed to the front of the uprights 20 through with self-tapping screws engaging screw holes which pass through the front of the uprights.
Such units were subjected to test protocols in accordance with the Generic Requirements document (GR-63-CORE of 1 October 1995) published 25 by Bell Communications Research, Inc.(Bellcore) and titled: Network Equipment-Building System (NEBS) Requirements: Physical Protection. It was found that full compliance was achieved with static testing, with the requirements for natural mechanical frequency and all of the dynamic tests that were run.
CA 0223~6~7 1998-04-24 Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent 5 to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.
The uprights may have a cross section with dimensions of 2 inches by 4 inches by 1/8 inch. The gusset plate may be 1/2 inch thick and also 25 may be made of steel.
Advantageously, the natural frequency of the rack in either a direction parallel to a plane of the uprights or transverse thereto preferably exceeds 6 Hertz.
CA 0223~6~7 1998-04-24 BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages will be apparent from the following detailed description, given by way of example, of a preferred embodiment taken in conjunction with the accompanying drawings, wherein:
Fig. 1 is a perspective view of the seismic resistant equipment rack;
Fig. 2 is a front elevation view of the equipment rack;
Fig. 3 is a detail diagram of an upper corner of the rack;
Fig. 4 is a partial section of the upper corner of the rack; and Fig. 5 is a side elevation view of a bottom portion of the rack.
DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS
Referring to Figures 1 and 2 the equipment rack 10 has two upright parallel tubular members 12 and 14 of rectangular cross section.
These uprights are 4 inch by 2 inch by 1/8 inch hollow structural steel sections.
Metal such as aluminum is too soft to provide sufficient strength. A cross member 18 joins upright members 12 and 14 at the top and is welded around the perimeter of the ends of cross bar 18. The cross member 18 is of the same cross sectional dimensions and the same material as uprights 12 and 14. In addition, as seen in Figures 3 and 4 two stiffening plates 30 and 32 are positioned to align with the top and bottom surfaces of cross bar 32 when the latter is in position to be welded to the uprights. The stiffening plates 30 and 32 have welds 34 and 36, respectively, extending around their perimeter which bond them to the inside of the respective uprights 12 and 14. Thus, there is a 3 o continuity of material all across the top through to the outside surfaces of uprights 12 and 14.
CA 0223~6~7 l998-04-24 The bottom of the two uprights 12 and 14 are welded to two right angle 1/2 inch thick steel gusset plates 16 and 26 with welds 44 and 42 formed along the top and bottom, respectively, of each plate at each upright 12 and 14 and by welds 41 and 43 along the sides of each upright at each of plates 16 and 26. In addition, steel stiffeners 20 are welded at each end on each side of the rack 10. The stiffeners 20 have welds 41 and 43 along each side of their line of contact with the plates 16 and 26. They provide resistanceto vibrational motion perpendicular to the plane of the rack. Welds 44 and 42 10 of the plates 16 and 26 to the bottom of the uprights 12 and 14 serve to resist shear due to vibrations in the plane of the rack 10. The bottom portion 24 of base plates 26 and 16 is anchored to a base support (not shown) which is usually a thick reinforced concrete slab. Heavy plate washers 38 and seismically rated anchors 40 are used to fasten the rack base to a concrete 15 floor through slots 22.
Utilizing strong steel members of rectangular cross section improves the resistance of the rack to fracture of these members and twisting.
Ordinarily, shelving and equipment is screwed to the front of the uprights 20 through with self-tapping screws engaging screw holes which pass through the front of the uprights.
Such units were subjected to test protocols in accordance with the Generic Requirements document (GR-63-CORE of 1 October 1995) published 25 by Bell Communications Research, Inc.(Bellcore) and titled: Network Equipment-Building System (NEBS) Requirements: Physical Protection. It was found that full compliance was achieved with static testing, with the requirements for natural mechanical frequency and all of the dynamic tests that were run.
CA 0223~6~7 1998-04-24 Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent 5 to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.
Claims (6)
1. A seismic resistant equipment rack, comprising:
(a) a pair of hollow tubular uprights having a rectangular cross section;
(b) a hollow tubular cross member extending across the top of said uprights from one of said pair to another and welded to said uprights around a perimeter of each end of said cross member;
(c) a stiffening device in each of said uprights proximate a top thereof for stiffening the top of the rack;
(d) a pair of gusset plates extending from a base of one of said uprights to another, said gusset plates welded to said uprights along a top and bottom thereof; and (e) a pair of stiffening elements welded at each side of said rack to each of said gusset plates and extending transversely to said plates.
(a) a pair of hollow tubular uprights having a rectangular cross section;
(b) a hollow tubular cross member extending across the top of said uprights from one of said pair to another and welded to said uprights around a perimeter of each end of said cross member;
(c) a stiffening device in each of said uprights proximate a top thereof for stiffening the top of the rack;
(d) a pair of gusset plates extending from a base of one of said uprights to another, said gusset plates welded to said uprights along a top and bottom thereof; and (e) a pair of stiffening elements welded at each side of said rack to each of said gusset plates and extending transversely to said plates.
2. A rack according to claim 1, including a pair of stiffening plates aligned with top and bottom surfaces of said cross member and welded in an interior of each of said uprights proximate a top thereof;
3. A rack according to claim 1, wherein said tubular uprights and cross bar are steel.
4. A rack according to claim 1, wherein said uprights have a cross section with dimensions of 2 inches by 4 inches by 1/8 inch.
5. A rack according to claim 1, said gusset plate is 1/2 inch thick and is made of steel.
6. A rack according to claim 1, wherein the natural frequency of the rack in either a direction parallel to a plane of the uprights or transverse thereto exceeds 6 Hertz.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86369097A | 1997-05-27 | 1997-05-27 | |
| US08/863,690 | 1997-05-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2235657A1 true CA2235657A1 (en) | 1998-11-27 |
Family
ID=25341585
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2235657 Abandoned CA2235657A1 (en) | 1997-05-27 | 1998-04-24 | Seismic resistant equipment rack |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2235657A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004019624A2 (en) * | 2002-08-20 | 2004-03-04 | Adc Telecommunications, Inc. | High density fiber distribution frame |
| EP2525636A3 (en) * | 2011-05-16 | 2013-01-23 | Middle Atlantic Products Inc. | Rack assembly |
| CN112274819A (en) * | 2020-09-16 | 2021-01-29 | 扬州水龙消防器材有限公司 | Fire-fighting equipment rack with protection function |
-
1998
- 1998-04-24 CA CA 2235657 patent/CA2235657A1/en not_active Abandoned
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004019624A2 (en) * | 2002-08-20 | 2004-03-04 | Adc Telecommunications, Inc. | High density fiber distribution frame |
| WO2004019624A3 (en) * | 2002-08-20 | 2004-04-29 | Adc Telecommunications Inc | High density fiber distribution frame |
| US6920273B2 (en) | 2002-08-20 | 2005-07-19 | Adc Telecommunications, Inc. | High density fiber distribution frame |
| EP2525636A3 (en) * | 2011-05-16 | 2013-01-23 | Middle Atlantic Products Inc. | Rack assembly |
| US9155383B2 (en) | 2011-05-16 | 2015-10-13 | Middle Atlantic Products, Inc. | Rack assembly |
| CN112274819A (en) * | 2020-09-16 | 2021-01-29 | 扬州水龙消防器材有限公司 | Fire-fighting equipment rack with protection function |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5383723A (en) | Earthquake resistant electronic equipment frame | |
| US20060043031A1 (en) | Electronic equipment rack | |
| US6293637B1 (en) | Earthquake-resistant electronic equipment frame | |
| US6349837B1 (en) | Stiffened relay rack | |
| US6036290A (en) | Seismic subframe for electrical enclosure | |
| US6561602B1 (en) | Equipment mounting racks and cabinets | |
| US5004107A (en) | Earthquake braced racks | |
| JP2000514603A (en) | Equipment rack | |
| JP2693906B2 (en) | Communication device mounting frame | |
| US6629614B2 (en) | Mounting for telecommunications equipment | |
| US6527351B1 (en) | Equipment mounting racks and cabinets | |
| US5979672A (en) | Earthquake resistant enclosure for electronic equipment | |
| US4899892A (en) | Earthquake-resistant electronic equipment frame | |
| US4073107A (en) | Curtain wall structure | |
| KR101681111B1 (en) | A high and low voltage metal-clad switchgear having earthquake-proof construction | |
| EP0784137A1 (en) | Apparatus and method for protecting buildings from earthquakes | |
| CA2235657A1 (en) | Seismic resistant equipment rack | |
| US5884886A (en) | Support frame for a structural component | |
| CA2053989C (en) | Rectilinear building structure | |
| KR101027917B1 (en) | External case for distributing board having earthquake-resistant frame | |
| US6889853B2 (en) | Earthquake-resistant equipment rack | |
| GB2299619A (en) | Anti-theft device for ATM | |
| JPH03129709A (en) | Transformer | |
| JP2000220318A (en) | Vibration control wall | |
| KR101518822B1 (en) | Earthquake-proof switch board installed with duct-type supporting parts |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |