Title:
Vitreous clay conduit rest section
United States Patent 2236801


Abstract:
This invention relates to improvements in the rest sections of vitreous-clay conduits such as are largely used underground to encase the piping of steam-transmission and other systems. Conduits of this character are usually shipped to the job in the form of short cylindrical sections, which,...



Inventors:
Mcdonald, Albert P.
Application Number:
US26151439A
Publication Date:
04/01/1941
Filing Date:
03/13/1939
Assignee:
Mcdonald, Albert P.
Primary Class:
Other Classes:
138/106, 138/108, 285/124.2, 285/188, 285/330
International Classes:
F16L7/00
View Patent Images:



Description:

This invention relates to improvements in the rest sections of vitreous-clay conduits such as are largely used underground to encase the piping of steam-transmission and other systems. Conduits of this character are usually shipped to the job in the form of short cylindrical sections, which, at the job, are split longitudinally into upper and lower halves. The lower halves are successively laid end to end on the upper concaved surface of a sectional base drain resting upon the floor of the trench in which the conduit is to be buried. The upper halves are placed over and cemented or otherwise secured to the lower halves, after the pipes,. pipe supports and insulating material have been installed, whereupon the trench is filled in.

The present practice usually employed in supporting pipes within the conduit sections is to mount the ends of semicircular cradles on the curved side walls of the lower halves of suitably spaced sections, usually termed "rest sections," and to rest the pipes upon rollers carried by a rod which bridges the cradle. This method has a number of objections, among which may be mentioned: it lacks stability because the cradle is subject to tilting and twisting during the expansion and contraction of the pipes; and it places the load directly on the curving walls of the conduit, subjecting them to breakage, particularly when water hammer is encountered.

To avoid these objections, it has been proposed to support the cradle rigidly on various types of metal mountings which extend through an opening in the lower half of the section downwardly into the supporting material forming the base of the trench. It has also been proposed, in Patent #638,931, to provide T-shaped conduit sections at the points of support and to fill the depending branch of the T with concrete within which the pipe supports may be rigidly mounted. All of these arrangements involve various objections such as a wide departure from standard practice, involving a corresponding increase in cost, while some are subject to electrolysis. The present invention is directed to an improved pipesupporting arrangement which is modeled somewhat generally after the arrangement shown in Patent #638,931.

The principal object of the present invention is to provide a safe, practical T form of rest section which avoids the disadvantages heretofore encountered and which involves a minimum departure from the standard conduit-system practice presently followed.

The invention is illustrated in the accompanying drawings, wherein: Figure 1 is a partly broken side elevation of a conduit system embodying my invention; Figure 2 is a spigot end elevation, and Figure 3 is a top plan view of the lower half only of the rest section, shown in Figure 1, with the cradle properly positioned in the section but partly broken away for the sake of clearness; Figure 4 is a perspective view of the cradle member; Figure 5 is a perspective view of the cradle insulator; Figure 6 is a vertical section taken transversely through the lower half of an installed rest section, this section corresponding generally to one taken along line 6-6 of Figure 1, and, specically, to one taken along line 6-6 of Figure 3, the cradle again being broken for the sake of clearness; and SFigure 7 is a fragmentary section taken along line 7-7 of Figure 6.

The illustrated embodiment of my invention includes a base drain B composed of a series of conventional base-drain sections I. The sectional base drain B forms a support for a sectional conduit C, which likewise is composed of a series of conduit sections 2 of conventional shape and arrangement, and a desired number of rest sections 3 which are interposed between conventional sections 2 at suitable intervals where the use of pipe supports is desired.

Each rest section 3 is of conventional tubular character. It is provided with open bell-andspigot ends and is longitudinally recessed or otherwise designed to permit its being longitudinally split, at the job, into upper and lower halves 4 and 5. Each lower half 5 is provided, on its outer bottom wall, with an integrally formed, longitudinally directed tongue 6 which cooperates with a corresponding groove in the upper face of the base-drain sections I to form a tongue-and-groove connection of the character described and claimed in my copending application, Serial #251,721, filed January 19, 1939. If desired, it may also be provided, along its inner, upwardly curving, side walls, with opposed, integrally formed, longitudinally directed ribs 7 of triangular cross section.

In accordance with past practice, the piping is arranged to rest upon one or more rollers 8 mounted on a rod 9 bridging the inner curvature of a semi-circular cradle 10 which is centrally positioned within, and transversely arranged across, the lower half 5 of the rest section. The end portions of the cradle member curve upwardly through open segment recesses I formed at corresponding positions in opposed inner rib walls 7, each recess terminating near a well or pocket 12 adjacent the inner wall. The cradle member additionally is integrally provided, at each end, with a T-shaped aligning anchor having a stem 13 and a head 14. The stem 13 of each anchor depends from the cradle into the adjacent pocket 12, while the head 14 of the anchor forms oppositely directed, longitudinally extending arms overlying the upper surface of the inner rib wall 7 and preferably in engagement therewith. With this arrangement, the cradle may be installed simply by lowering it into place, and, when installed, is rigidly held against displacement as explained in my copending application, Serial #261,515, filed March 13, 1939, wherein a similar form of mounting is described and claimed.

In accordance with my invention, each rest section is supported directly upon the floor of the trench by piers 15 which are formed integrally on the rest section to depend vertically from the cradle engaging areas thereof and which straddle the adjacent portion of the base drain. The weight of the piping may thus be transmitted from the ends of the cradle 10 directly through the vertical piers 15 to the floor of the trench.

By so doing, such weight is transmitted along straight lines vertically through the piers thus subjecting them to safe compressive stresses only and thereby avoiding the dangerous tensile stresses which are created when the weight of the piping is transmitted along curved lines through the circularly curving bottom wall portion of the rest section.

The specifications in some installations require the piping weight to be transmitted from the cradle to the floor of the trench through some safe agency other than the walls of the rest section.

To meet this requirement, it is only necessary to provide, in the bottom of the rest section between piers 15, an opening 16 through which suitable weight-transmitting means may extend. A suitable arrangement is shown wherein the bottom of the cradle rests upon a bed 17 of cement which extends over the upper surface of the base drain.

To avoid the transmission of all the piping weight through the base drain, the cement bed is made in the form of a saddle having legs which extend downwardly between the piers and the outer sides of the base drain to the floor of the trench. To this end, the vertical inner faces of the pier are concavely curved to provide the space necessary to accommodate the legs of the concrete saddle.

The cement bed or saddle 17 should, of course, raise the cradle sufficiently to relieve the conduit walls of the piping weight but insufficiently to prevent such walls from holding the cradle against displacement.

Inasmuch as the direct contact between the cradle 10 and the concrete saddle 17 may subject the cradle to electrolysis, direct contact therebetween, preferably, is avoided by interposing, between the cradle and the saddle, an insulator 18 composed of any suitable material such as baked vitreous clay.

Having described my invention, I claim: 1. In a conduit system: a base drain resting on a foundation; a conduit rest section, having opposed cradle-engaging areas, arranged over the base drain and vertically removable therefrom; and drain-straddling piers integrally formed on the rest section to depend from the cradle-engaging areas thereof substantially vertically along opposite sides of the base drain into firm contact with the foundation.

2. An improvement in conduit systems of the character having: a series of base-drain sections arranged in end-to-end relation on a foundation; a series of bell and spigot conduit sections arranged in end-to-end relation over the base drain; and a bell and spigot rest section, having opposed cradle-engaging areas, interposed in the series of conduit sections and arranged in end-to-end relation with adjacent members thereof; comprising: weight transmitting piers for supporting said rest section directly upon said foundation, said piers being integrally formed on the rest section to depend from the cradle-engaging areas thereof substantially vertically along opposite sides of said base drain into firm contact with the foundation.

3. In a conduit system: a base drain resting on a foundation; a conduit rest section, having a bottom opening, arranged over the base drain; drain-straddling piers integrally formed on the rest section, at opposite sides of said opening, to depend substantially vertically into engagement 4 with the foundation; a cradle member transversely arranged within said rest section over said opening, the ends of said cradle engaging the side walls of said rest section adjacent the upper ends of said piers; and a saddle supporting said cradle Supon said foundation, said saddle extending across the top of the base drain at the bottom opening of the rest section with its end portions extending downwardly, between the sides of the base drain and the adjacent faces of the piers, Sinto engagement with the foundation.

ALBERT P. McDONALD.