US3022972A - Supporting trough - Google Patents

Description

Feb. 27, 1962 R. F. E. BUNSTON SUPPORTING TROUGH 5 Sheets-Sheet 1 1 Filed July 21, 1959 UUEEEEE FL .I

INVENTOR Roy 5 E. BunsTon AZwL M A TTOR VEY R. F. E. BUNSTON SUPPORTING TROUGH Feb. 27, 1962 5 Sheets-Sheet 2 Filed July 21, 1959 INVENTOR 207 15 5uns7on BY 4 TTORNEY Feb. 27, 1962 R. F. E. BUNSTON SUPPORTING TROUGH 5 Sheets-Sheet 3 Filed July 21, 1959 HIUHIUUUHIUHUUHIUD IN V EN TOR Roy E E. BunsTon EUODDDDDUEDD:

BY .JiMZM A TTORNEY Feb. 27, 1962 R. F. E. BUNSTON SUPPORTING TROUGH 5 Sheets-Sheet 4 F I G .l4

Filed July 21, 1959 FIG .9

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' I SUPPORTING TROUGH Filed July 21, 1959 5 Sheets-Sheet s FIG.IO

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' IN V EN TOR. Roy E E. Buns'lbn IZZ 14 TTORNEV United States Patent 3,022,972 SUPPORTWG TRGUGH Roy F. E. Bunston, Markham, Ontario, Canada, assignor to Burndy Corporation, a corporation of New York Filed July 21, 1959, Ser. No. 828,638 8 Claims. (Cl. 24868) This invention relates to supporting trough and, more particularly, to cable or pipe tray units which may be joined to form a unitary supporting trough system.

Cable and pipe supporting trough systems are extensively used in power stations and large industrial plants to support a plurality of cables or wires for the transmission of electrical energy and for the support of piping or tubing used in the transmission of fluids both liquid and gaseous. Usually, a plurality of prefabricated channel or tray units are assembled at the plant location to form the supporting trough system.

In the past the prefabricated cable tray units have generally been one of two forms. The first type may be designated as a mesh channel unit. Such mesh units included a bottom for the trough which was usually manufactured of expanded sheet metal. The expanded metal bottom was joined along its longitudinal edges to channel supports or side rails. In one embodiment of this type of mesh channel unit, the expanded metal bottom had its edges upturned to provide side walls for the trough. The upstanding edges of the expanded metal were finished ofi by attaching a sheet metal binder strip to the edges of the wall in order to present a smooth lip which would not cut into the cable.

The second type of channel unit may be designated punched sheet metal type channel unit. The channel unit of this known type was generally formed of a single sheet of metal in which the sides of the trough unit were constructed by forming or bending the two opposite portions of the sheet metal bottom to form the upstanding walls. Transverse slits were punched in the bottom of the unit intermediate the wall portion and the edges of the slots were downwardly extruded to provide a rounded lip for each of the slits.

The mesh type of channel unit provided a substantial air fiow through the openings in the bottom and the slits in the punched sheet metal type provided a similar but somewhat lesser flow of air. The mesh unit was difficult to interconnect to other units while the downward turned edges of the slits in the punched sheet metal type often interfered with the easy support of the trough system. Both types of units required a relatively heavy gauge of metal to be used in order to support the weight of the cable and piping carried by the system and to allow for a proper margin of safety in the event that workmen used a trough as a catwalk during construction of the plant or building in which it was installed. In addition; the required heavy metal gauge made the prefabricated unit quite heavy and awkward to handle during installation.

In certain locations it is necessary to install covers for the trough unit to prevent the accidental dropping of tools 7 'iee a new and novel supporting trough unit which is materially stronger than the prior art units described.

Another object of this invention is to provide a new and novel cable tray unit which is substantially lighter in weight than known types of trough when comparedto units of equal supporting strength.

Still another object of this invention is to provide a new and novel supporting trough unit which provides for both a transverse and vertical air circulation around the supported elements.

Further objects of this invention provide for the ease of attachment of cables or piping to the trough structure; for the ease of support of the assembled system and in general for all the advantages of the known trough units in addition to unique advantages unknown in the Prior art while overcoming the disadvantages of the known supporting trough systems.

According to the present invention, the cable tray unit comprises a bottom and two longitudinally extending supporting channels. The bottom of the tray comprises a ribbed floor having alternating ridges and grooves. The ridges extend the full transverse width between the side channels to provide additional strength to the floor as a result of this beam effect. The grooves between the ridges include a plurality of cut-outs or holes intermediate the side channels to provide for vertical air flow and for the clamping or lashing of the wires, cables or pipes to the tray unit.

The supporting channel side elements include formed stiffening rib elements which longitudinally extend the length of the tray to provide additional strength in the longitudinal direction. The side rails include folded over or formed top elements to materially increase the strength and to protect the ends of screws utilized in attaching covers to the tray element.

The above-mentioned and other features and objects of the invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of the ribbed bottom for use in the cable trough of this invention;

' FIG. 2' is a cross-sectional view of theribbed bottom taken along lines 2-2 of FIG. 1;

FIG. 3 is a perspective view of the side rail for use in the cable trough of this invention;

FIG. 4 is a perspective view of the cable trough units assembled to form a cable trough system in accordance with the principles of this invention;

FIG. 5 is a perspective view of part of a cable trough system utilizing the cable trough units of this invention;

FIG. 6 is a perspective View partly in section showing the means for joining the cables to the cable trough units;

FIGS. 7, 8, and 9 are various embodiments of bend section units for use in conjunction with the cable trough units of this invention;

FIG. 10 is one embodiment of a cross connector for use in assembling a cable trough system;

FIG. 11 is a partial view in perspective of the supporting element for use in the cross connector of FIG. 10;

FIG. 12 is an alternate embodiment of a cross connector for use in a cable trough system;

FIG. 13 is a perspective view partly in section of a corner support for use with accessories used in the cable trough of this invention;

FIG. 14 is a plan view of a reducer section for use with the cable trough system of this invention;

FIG. 15 is a perspective view of a ladder type cable trough in accordance with the principles of this invention and FIG. 16 is a cross sectional view of the cable trough unit of this invention with a cover attached.

Referring to FIGS. 1 and 2 of the drawing, a cable tray bottom member 16 for use in the cable tray unit of this invention is therein shown to comprise a plurality of alternating ridges l2 and grooves 1 Each ridge 12 had a flat floor section 16 joining the vertically depending side flanges 18. The ridge sections 12 extend the full width of the bottom 10. The groove section 14 joins the bottom of the vertically depending flanges 18 of the ridge 12. A plurality of spaced connecting strips 29 join the depending flanges l8to form a plurality of openings or holes 22 which may. be punched out of or otherwise formed in the grooves 14 to fashion the connecting strips 29. The connecting strips 26 provide additional support against transverse forces.

Referring to FIG. 3 of the drawing, one of the side rails 24 for use in the cable tray unit of this invention is therein shown to comprise a rolled steel form having a horizontal member or supporting lip 26 and a vertical member or side wall 28. The vertical side wall 28 has a longitudinally extending integral stiffening rib 36 formed therein to provide a beam effect which materially assists in resisting deformation in an axis perpendicular to the longitudinally extending axis of the side rail 24. The upper portion of the vertical side wall 28 is turned in on itself and folded over the provide a finished edge 32 having a longitudinally extending hollow of rectangular cross section 34. The end 36 of the side rail 24 is formed in such a manner that it is slightly spaced apart from the vertical side wall 28. Such spacing permits complete galvanizing or otherwise plating to protect the entire side rail 24 against corrosion. However, when forces due to the weight of the cables or pipes supported are applied to the lip 26, the silght opening between end 36 and wall 28 tends to close, providing additional resistance to deflection of the side rail 24. An additional stiffening rib 38 is formed where the lip 26 meets the vertical wall 28. The combination of the folded over end 32 and the stifienin ribs 30 and 38 provide a strengthening section modulus which, combined with the ribbed flooring provides great rigidity, both longitudinally and transversely.

Referring to FIG. 4 of the drawing, the assembled cable tray of my invention is therein shown to comprise a pair of side rails 24 similar to those illustrated in FIG. 3 and a bottom member as shown in FIG. 1 which is integrally joined to the lips 26 of'the side rails 24 by means of spot welding in the groove margins as shown by reference numeral 40 or otherwise attaching the ribbed bottom 10 to the side rails 24. Each supporting trough unit is terminated by coupling means 42 so that they may be easily assembled to form continuous length of trough.

The coupling means illustrated comprises mating hinge elements 44 and 46 attached to the ends of the side rails 24 of each trough unit 48, 50 and 52. The mating hinge units 44 and 46 are positioned in such a manner as to cause their coupling elements 54 to interleave and a coupling pin is inserted to join the side rails ends as shown at 58. It is, of course, obvious that other coupling means can be utilized to join the cable tray units.

The ribbed floor 10 of the trough units with its plurality of ridges 12 extending between the side rails 24 act as beam members providing a maximum resistance to transverse deflection, giving a maximum strength to the entire unit. The stiffening ribs 34 and 38 in addition to the folded over portion 36a of the side rails provide rigidity along the longitud nal axis of the unit. Due to the additional -strength provided, the supporting trough of my invention has equal or better strength when compared to the prior art units. For example, in order to support 100 pounds of pipe or cable plus a workman on a 24 inch Wide trough, the prior art units found that it was necessary to use a 14 gauge metal in forming the trough. The supporting trough of this invention can support the same load by using 20 gauge metal for the bottom with 16 gauge material for the side rails. In general, the prior art devices having a mesh bottom were 15% heavier than the cable tray of this invention. This lighter weight makes this trough easier to install, more economical and allows it to be supplied in longer lengths than the prior art units.

Again referring to FIG. 4 it is seen that units 48 and 50 may be joined without the use of any joiner strip. The unique design of the ribbed bottom 10 permits the tray units to be out along a groove 14. Since the pipe or cable rests on the floor 16 of the ridges 12 the supported elements do not come in contact with the cut edge and this eliminates the danger of damaging the cable insulation eliminating the need for a joiner strip.

As shown in FIG. 5, the assembled trough units may be supported by means of a hanger fixture 60 of the trapeze type depending from an overhead support. Since no portion of the trough depends below the lips 26 of the side rails 24, an even undersurface is achieved which allows ease in supporting the unit. Alternately, the trough units may be supported by a cantilever beam 62 supported by an insert 64 mounted to the vertical wall. The cantilever beam 62 is terminated by an upstanding lip 66 en.- gaging the side wall 28 and end 32 of the rail 24 and preventing inadvertent lateral movement of the trough units.

Referring to FIG. 6 there is therein shown various means for attaching the pipe or cable 68 and 70 to the tray bottom 10 of this invention. The supported pipes or cable 68 and 7t rests on the elevated portion 16 of the ridges 12 formed in the ribbed floor 10. A cable clamp 72 of standard size and shape may be inserted in the openings 22 formed in the grooves 14 on the ribbed door It). The nut and bolt 74 of the cable clamp 72 are tightened to firmly grasp the cable 68 and resist move.- ment transverse to the axis of the tray. Alternately, the cable may be lashed to the connecting members of the grooves by means of a cord or wire 76. Thus the cables may be attached either to the opening 22 or to the com necting strips 20 as is deemed most desirable for the particular application. It is also apparent from'FIG. 6

that vertical air circulation is provided through the open.- ings 22 in the ribbed bottom 10 and around the cables by air flow in the grooves 14. These mutually perpendicular air currents tend to provide adequate cooling for the cable.

In order to provide accessory units for the cable tray system of this invention so that they may be formed into a system, various accessories are shown in FIGS. 7-14.

FIG. 7 illustrates one method of providing a bend to join two straight tray units to change the axial direction of the system. The bend of FIG. 7 is formed of two curved side rails 78 and 80 and a ribbed bottom 82. The bottom unit 82 is formed of wedge shaped ridges 84 and radially extending grooves 86. The width of the grooves 86 is maintained constant so that the same punch equipment utilized to form the grooves in flooring 0* the straight units may be used in forming the curved flooringof FIG. 7. The sheet metal bottom 82 is placed under the punch to form the first groove and the material is then rotated and moved to form the successive grooves in the bend. The bottom 82 is integrally joined to the side rails to form the bend. In order to provide for ease of attachment the Wedges are formed with a depressed portion 86 where additional spot Welding is utilized to form a more rigid unit. It has been found where the width of the bend is increased, additional air How is advantageous. In order to provide this additional air flow auxiliary radial grooves 88 are formed in the wedge-shaped ridges of the bend. These-auxiliary radial grooves 88 do not extend the full length of the floor but are incorporated in the width portion of the wedge shaped ridges. It is, of course, realized that whereas the bends illustrated have their inner and outer side rails curved about a common center, it is equally possible to form these side rails with a'common radius so that the curves or bends will smoothly fit together in a horizontal plane.

Referring to FIG. 9 of the drawing, an alternate embodiment of a bend 90 is therein shown to comprise a plurality of straight section rib floors 92 and 94 which have been cut to form the bend-90. A corner brace 96 similar to the brace illustrated in FIG. 13 and hereinafter described is utilized to provide the support between the inner side rail 78a and the straight sections 92 and 94 of the ribbed flooring.

Referring to FIG. 10, one embodiment of a crossconnection is therein shown to comprise a plurality of straight ribbed flooring sections 98, 99, and 100 which have had their corners removed and are supported by a brace 102 similar to that shown in FIG. 11. The brace 102 is joined at its ends to the lips of the paired rails 104, 106 and 108, 110, and provides a supporting lip 112 to which the ends of the straight ribbed floor bottoms 98 and 100 are joined. The lip 112 of the supporting brace 102 is integrally formed with a reinforcing ridge or beam section 114 which fits under the end ridge 116 of the ribbed flooring section 98 while the lip 112 supports the end of flooring sections 100.

Alternately, straight sections of ribbed flooring 118, 120 and 122 may be utilized to form a cross connector such as illustrated in FIG. 12 which is composed of the ribbed flooring section, four curved side rails 124 are joined at their outer extremeties to the straight ribbed floor sections and corner brace 126 such as illustrated in FIG. 13. The corner brace 126 used in conjunction with ribbed flooring sections includes a supporting beam 128 and a corner 130. The corner 130 formed with a lip 132 which is utilized to support the side of straight section 102 in FIG. 12 or the edge of straight section 92 in FIG. 9. The depressed portion 134 of the corner 130 is spot welded to the lip of the inner side rail. A support member 136 has its ends joined to the lips of the side rail and supports the corner 130. The lips 138 of the support member are utilized to support the edge of the straight ribbed floor section 118. Thus the silled floor sections are supported on the lips 132 and 138 of the corner base member 126.

FIG. 14 illustrates one embodiment of a reducer section 140 for joining wide and narrow straight trough sections. The reducer section is composed of a ribbed floor section 142 cut to the desired width and one straight rail section 114 and a bent rail section 146. The rail sections 144 and 146 are similar to the rail illustrated in FIG. 3 and the rolled bottom 142 is joined thereto.

Referring to FIG. 15 an embodiment of a ladder type cable trough 148 is therein seen to comprise a pair of side rails 15!) and 152 similar to the side rails illustrated in FIG. 3 integrally joined by a plurality of spaced bracing ladder rungs 154. Each ladder rung 154 is ribbed or corrugated to form a plurality of beam units having flat floor sections 156 joining depending flanges 158. A plurality of interconnecting strips 160 join the bottom edges of the depending fianegs 158 of the rungs 154 to form the grooves sections. The rungs 154 are integrally joined to the lips 162 of the side rails 150 and 152 to form a continuous ladder structure.

Due to the beam effect of the rungs 154 and the stiffened side rails 150 and 152 the unit illustrated in FIG. 15 achieves substantial rigidity against vertical and transverse deflection.

Referring to FIG. 16 it is often desirable to append a cover to the cable tray of this invention. Since the edges 164 of the side rails are folded over to provide a flat top surface enclosing a protected hollow section, it is merely necessary to place a sheet metal cover 166 extending between the folded over edges 164 and use sheet metal screws 168 to join the cover 166 to the side rails. The ends of the screw 168 are disposed within the hollow of the folded edges and are thus prevented from damaging the cables inadvertently. Alternately the cover may be formed with a lip 170 and the screw 172 inscrted from the side.

. I have thus described my invention, 'but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, 'andthat the invention maybe carried out in other ways without departing from the spirit of my invention, and therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention are attained and new results accomplished, as it is obvious that particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

I claim:

1. A supporting trough, comprising: a pair of spaced apart, longitudinally extending side rails; each rail comprising a vertical member and a horizontal member; a plurality of longitudinally spaced apart transverse beams interconnecting said pair of side rails; said plurality of beams comprising a plurality of vertical members and a plurality of upper and lower horizontal members alternately interconnecting the upper edges of adjacent vertical members and the lower edges of adjacent vertical members; each end of each said lower beam horizontal member overlapping a rail horizontal member and attached thereto.

2. A supporting trough according to claim 1 wherein each said lower beam horizontal member has a plurality of holes formed therein.

3. A supporting trough according to claim 1 wherein said vertical and horizontal members of said rails are flat plates each joined to the other along an edge thereof; said vertical plate being divided into a minor portion adjacent the free edge of said vertical plate, and 'a major portion adjacent the edge attached to said horizontal plate, said minor vertical plate portion bent out of the plane of said vertical plate, first in a direction normal to the vertical plate plane and towards the center of the trough, then parallel to the vertical plate plane and towards the center of the trough and finally normal to the vertical plate plane and towards said vertical plate plane, said free edge being located adjacent yet spaced from said major vertical plate portion.

4. A supporting trough according to claim 1 wherein said horizontal and vertical members are provided by a single sheet of metal bent into an L-shaped cross-section, said horizontal member being below said vertical member.

5. A supporting trough, comprising: a pair of spaced apart, longitudinally extending side rails; each rail comprising a vertical member and a horizontal member; a trough bottom between said pair of rails comprising a corrugated sheet having transverse parallel, spaced apart corrugations extending from sheet edge to sheet edge, said corrugations forming said sheet into spaced apart transverse vertical and upper and lower horizontal elements; the ends of said sheet lower horizontal elements overlapping and attached to said rail horizontal members.

6. A supporting trough according to claim 5 wherein each said sheet lower horizontal element has a plurality of holes formed therein.

7. A supporting trough according to claim 4 wherein said vertical and horizontal members are flat plates each joined to the other along an edge thereof; said vertical plate being divided into a minor portion adjacent the free edge of said vertical plate, and a major portion adjacent the edge attached to said horizontal plate, said minor vertical plate portion being bent out of the plane of said veiti'cl ialt, fi'rst "in 5 dii'btibh fibir'hel 't?) 'th iiftiiil pllte plane and tbwards the center 6f the tru'gh, then parallel to the vei'tical 'plate plane afid towards the efitei Of the trough and finally normal t6 the vertical 'plate 'pl'a'n hd towards said 've'rtical plate plane, "said free edge being located adjacent yet spaced from said mjor verfica-I plate por tio n.

8. A supporting trough ae'cbrdin'g {0' elai'm 5 wherein said horizbntl and vertical members are provided by a single sheet of metal hen; into an 'L' shped 'crbseetion, Sid horizontal member being belbw 893d 'Vfticl ihem= ber.

Reta-mesfined 'an the me bf this patch UNITED STATES PATENTS

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