US3858614A - Cable trough - Google Patents

Abstract

A precast concrete trough having a first member with bottom cross braces, sides and removable top and a second member having a single cross brace and sides fitting exterior of the first member.

Description

United States Patent 11 1 1111 3,858,614 Moore et al. 1 1 Jan. 7, 1975 [54] CABLE TROUGH 2,862,367 12/1958 Silverstein ct a1. 61/11 1 1 William Gabe" Moore; Frank 1 331231332 51133? F3317???51:11:11: .31.???1133 Hendricks, Jr., both of R0. Box 3573, 5000 Castlewood Rd., FOREIGN PATENTS OR APPLICATIONS VKiQ A QQQQLAYQ .5 Mn 61,476 4/1968 Germany 138/105 23,953 8/1901 Switzerland... 138/105 [22] filed. Nov- 1972 1,221,181 1/1960 France 138/155 [21] Appl. No.: 306,870

- Related U.S. Application Data Primary Examiner-Herbert Goldstein [63] Continuation-impart of Ser. No. 158,706, July 1, Attorney, Agent, -M Bernard, Brown 1971. Roberts & Sutherland [52] U.S. Cl. 138/105, 174/37 51 1111.01. F161 1/00,1-:02 1 29/10 1571 ABSTRACT Fieid of Search 138/103 105, 108, A precast concrete trough having a first member with 138/175; 61/11; 174/37 38, 48 bottom cross braces, sides and removable top and a second member having a single cross brace and sides [56] References Cited fitting exterior of the first member.

UNITED STATES PATENTS Mahoney et a1. 138/175 2 Claims, 6 Drawing Figures 'II-ATENTEDJAN 71975 3.858.614

SHEET 3 OF 3 CABLE TROUGH CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part, and claims the priority of our prior patent application entitled Cable Trough tiled July 1, 1971, Ser. No. 158,706.

BACKGROUND OF THE INVENTION Control cable and metal conduit in electric power substations must be enclosed and protected to prevent abrasion with a consequent breaking of insulation and power failure. Prior methods of protecting the cable include direct burial or burial of the cable encased in plastic conduit, aluminum cable trays, and poured in place concrete cable troughs.

There has heretofore been invented a precast concrete structure, which when assembled, forms the basis for an underground trench. It is illustrated in US. Letters Pat. No. 3,862,367, entitled Precast Cable Trench. It includes a bracket having upstanding posts, supporting ledges outside the posts and a central base. Separate side wall panels rest on the ledges and are biased against the posts by the dirt fill when the device is in stalled in a trench.

SUMMARY OF THE INVENTION This invention is a precast concrete trough that has a unitary base adapted for completely above ground installation. The unitary base member has cross braces on which the conduit may rest and side members which support and protect the conduit and serve as a mounting for the protective top.

The principal advantage of this invention is the ease of installation and consequent cost reduction in building the substation, and ultimately, the cost of electric power to the consumer. After major construction of the substation, this concrete trough may be rapidly put in place, directly on the ground, and the cables laid thereon with little or no prior preparation of the ground and no subsequent replacement of the fill.

This is in contrast to the prior cable casing devices which require the construction of a trench before installation of the cable protective device and the cable itself, and then require the replacement of the dirt into the trench and the removal of the excess fill.

The invention will be further described with reference to the attached drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of the cable trough including the slip joint, end closures, and universal angle joint section.

FIG. 2 is a perspective drawing of an underground installation partially cut away.

FIG. 3 is a cross-section of the cable trough taken on lines 3-3 of FIG. 2.

FIG. 4 is a perspective of an above-ground installation showing the universal joint abutting a control station.

FIG. 5 is a perspective view of the cable trough as assembled prior to filling in an underground installation.

FIG. 6 is a cross-section taken on the lines 6-6 of FIG. 5.

DESCRIPTION OF PREFERRED EMBODIMENTS The major components of this invention are the cable trough 10, the slip-joint 11, the trough cover 12, the end closure 13, and the universal angle joint 19.

Each individual cable trough 10, is an integral precast reinforced concrete body. It has side walls 20 and 21, which are connected at the outer edges of the lower inside wall, by trough bottom braces, 22 and 23. Each brace has reinforcing bevel 24 at either end. The brace is generally rectangular with rounded edges at the top to prevent abrading the cables.

The side wall has hand holds 25, on the outer surfaces, and has an internal taper in the vertical plane 26, and a bevel 27.

The tapered feature of the side wall allows the cable trough 10 to be cast in the inverted position and removed easily from the mold while the end bevels 27 allow a more secure interfitting of the pieces in the assembled form. The top cover as shown is half the length of each individual cable trough, and is a unitary structure having a body 30 and recesses 31, to allow a secure fit on the top of the side walls. Both the cable trough 10, the trough cover 12, and the other portions will have conventional reinforcing bars 28.

The end closure 13 has a terminating wall 34 of a height equal to the height of side walls 20 and 21 of the cable trough. The end closure also has side braces 35 and 36, at the end of the terminating wall, and spaced apart so that they may slide with their inner surface slightly outside the outer surfaces of side walls 20 and 21 of the last cable trough.

The slip-joint 11 is attached to the center of sliding walls 38 and 39. These sliding walls are spaced apart a distance, like the side braces of the end closure, to allow them to slide with their inner surfaces slightly outside the outer surface of the side walls of the cable trough.

The universal angle joint 19 has, as parts, four posts 14, four drive pins 15, one or more blanks 16, a frame 17, and a series of universal joint covers 18.

The four posts are spaced so that their inner surfaces fit outside outer surfaces of the connecting cable troughs 10. The drive pins are partially inserted in the ground and the posts are mounted on the pins through post bores 40.

The frame 17 is a unitary structure having four angle iron spanning bars 42, joined at their ends and having downwardly facing frame pins 43 which cooperate with the upper end of the post bore 40 to further align the universal angle joint and to serve as a mount for the universal cover 18, which has a cover body 46 and end recesses 47 to allow a secure fit between the cover and the frame.

The inner sides of the posts 40 have vertical post grooves 41 which allow blank 15 having the blank body 44 and blank tongue 45 to interfit when the universal angle joint is used as an L or T joint rather than a crossjoint.

OPERATION OF THE INVENTION The operation of this invention will be described primarily with respect to its construction and installation since the structure operates only in repose to protect the cable.

The installation will of course depend on where the cables are to be strung and which types of cables are involved. Shown in FIG. 4 is a cable running from the ladder entrance of control house 55, through the uni- 3 versal angle joint to a cable getaway into an underground metal conduit 53.

A particular feature of this invention is that this cable trough is as well suited to above-ground installation As below-ground installation. The above-ground installation is illustrated in FIG. 4 while a below-ground installation is shown in FIG. 2, which requires digging a tench 50, followed by installation of the cable trough, and then backfilling and carting leftover fill.

Each of the cable trough sections are laid in place in abutting ajoinment, with their beveled ends assuring a more complete seal. I

The position of the universal angle joint would conventionally be laid out initially, the pins driven into the ground and the posts mounted thereon. I

As the line of cable troughs approach the terminating point, the slip-joint may be used to fill in the side wall space between two fixed points. I

The end closure is also somewhat laterally adjustable to form a termination for cable troughs leading to an underground conduit getaway.

After the cable troughs are installed, but before the conduit is laid in place, a fill 51 such as a few inches of pea gravel, is placed in the section between the cross braces. This fill insures proper drainage and also holds the above-ground installation in position.

The conventional flexible control cable 52 or the metal conduit 53 may be placed directly on top of the cross brace 22. An alternative is to use a wall fastener 56 to hold the conduit above the floor of the trough.

I claim:

1. A precast concrete trough for supporting and enclosing electric cables for above-ground or belowground installation, which comprises a series of abutted sections in which each section has:

a. a unitary base member including side walls and cross braces,

b. said cross braces of generally rectangular cros section,

c. said cross braces having enlarged reinforced bevels at either end,

d. said cross braces in parallel alignment and abutting the inner surface of said side wallsat the lateral extremities of said side walls,

c. said cross braces further aligned so that their lower surface is aligned with the lower surface of said side walls,

f. said side walls case into the unitary base piece with said cross braces to form a unitary free standing structure capable of supporting and enclosing the electric cables in an above-ground installation, an aperture formed by the side walls and the cross braces in the bottom of the section for entrance and exit of the electric cable,

h. a top member demountably attached to the base member and spanning the distance between the side walls, said top member generally rectangular and forming a load bearing surface.

. an expansion section having a single elongated, generally rectangular, base section with enlarged bevels at either end and a pair of side walls, said cross brace abutting said side walls at the center of the inner surface, the lower surface of the cross brace further aligned with the lower surfaces of the side walls, the inner surfaces of the side walls so spaced apart to slide outside the outer surfaces of the side walls of the said abutting sections.

2. The combination of claim 1 further including an angle section assembly for interconnecting runs of troughs, said angle section comprising four vertical rectangular posts, each post having a central bore, anchoring pins adapted for partial sinking in the ground, said stakes cooperating with said bore, a rectangular spanning frame having depending pins, said pins cooperating with the bore at the top of said posts, said spanning frame of a length to space said vertical posts apart so that the inner surfaces of the posts fit outside the outer surface of the vertical wall of said abutting sections, said vertical posts having on their inner walls vertical grooves, a blanking wall fitting in said vertical grooves and blanking the space between said posts and top sections resting on said spanning frame.

Claims (2)

1. A precast concrete trough for supporting and enclosing electric cables for above-ground or below-ground installation, which comprises a series of abutted sections in which each section has: a. a unitary base member including side walls and cross braces, b. said cross braces of generally rectangular cross section, c. said cross braces having enlarged reinforced bevels at either end, d. said cross braces in parallel alignment and abutting the inner surface of said side walls at the lateral extremities of said side walls, e. said cross braces further aligned so that their lower surface is aligned with the lower surface of said side walls, f. said side walls case into the unitary base piece with said cross braces to form a unitary free standing structure capable of supporting and enclosing the electric cables in an above-ground installation, g. an aperture formed by the side walls and the cross braces in the bottom of the section for entrance and exit of the electric cable, h. a top member demountably attached to the base member and spanning the distance between the side walls, said top member generally rectangular and forming a load bearing surface. i. an expansion section having a single elongated, generally rectangular, base section with enlarged bevels at either end and a pair of side walls, said cross brace abutting said side walls at the center of the inner surface, the lower surface of the cross brace further aligned with the lower surfaces of the side walls, the inner surfaces of the side walls so spaced apart to slide outside the outer surfaces of the side walls of the said abutting sections.

2. The combination of claim 1 further including an angle section assembly for interconnecting runs of troughs, said angle section comprising four vertical rectangular posts, each post having a central bore, anchoring pins adapted for partial sinking in the ground, said stakes cooperating with said bore, a rectangular spanning frame having depending pins, said pins cooperating with the bore at the top of said posts, said spanning frame of a length to space said vertical posts apart so that the inner surfaces of the posts fit outside the outer surface of the vertical wall of said abutting sections, said vertical posts having on their inner walls vertical grooves, a blanking wall fitting in said vertical grooves and blanking the space between said posts and top sections resting on said spanning frame.

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