USRE18785E - A corpora - Google Patents

Description

CURRIE April 1933.

SEWER PIPE Original Filed Aug. 2, 1929 c Wf W Cay 7" WM Q2 5 Reissued Apr. 4, 1933 UNITED STATES PATENT OFFICE CLARE H. CURRIE, OF WEBSTER CITY, IOWA, ASSIGNOIBI, BY MESNE ASSIGNMENTS, FIFO L. E. ARMSTRONG REALTY &INVESTMENT 00., 0F FORT DODGE, IOWA, A CORPORA- TION OF IOWA SEWER PIPE Original No. 1,834,603, dated December 1, 1931, Serial No. 383,005, filed August 2, 1929. Application for reissue filed January 13, 1933. SeriaLNo. 651,501.

This invention relates to improvements in sewer pipe, and more particularly to pipe or pipe lines used in large sewage handling and disposal systems and method of constructing the same. I

By alluding to pipe for sewage systems of large capacity, a distinction is made between the precast vitrified clay pipe used for laying small sewage pipe lines and those of large dimensions which are usually made continuous and of concrete moulded in forms erected in the trench or excavation. For sewage conveying, however, it is es:- sential to protect or cover the surface of concrete pipe lines from the destructive and corrosive action of the acid constituents of the sewage being handled, and therefore it is common practice to line the inner surface of concrete pipe with a non-corrosive material, such as vitrified clay. I

In the present disclosure this lining has the form of thin segmental plates called liners, and the purpose of the'invention is .to provide an improved. method for anchoring the liners to the surrounding concrete body of the pipe, and further to provide a method of construction for pipe lines which will insure the sealing of the inner lining to the passage of gases to the'concrete and otherwise lend itself to the erection of continuous poured concrete pipe lines as dist' guished from pre-cast' pipe sections, although the latter is also contemplated. I

A preferred embodiment of .my invention is disclosed in the accompanying drawing, in which i Figure 1 is a view in cross section of a sewer pipe constructed in accordance with .my invention;

Figure 2 1s a view in longitudinal section through the plpe as taken on line 2-2 of Figure 1;"

Figure liner, and r a Figure 4 is an-enlarged detail view in cross section of the pipe at one of the lugs, showing the several forms that may be used.

As clearly shown in Figure 1, the pipe is cylindric in shape and of the required diameter and thickness, and consisting of an out- 3 is a perspective view of a single er layer or shell 1 of concrete and an inner layer or lining of vitrified clay'2, made up of a multitude of pre-cast segmentsor CHIVlIlH-Q ear plates '3 joined with each other by lap j oints at their four edges. The concrete outer shell is considerably thicker than the inner lining, in fact, the thickness of the lining not a vital factor as its function is primarily that of a protective coating for the inside of the pipe.

Each liner or segmental plate is rectangu lar in shape, either square, or elongated in one direction, as desired, but curved on an arcof a circle corresponding to theinternal diameter of the pipe. As shown in Figure 3,

each liner is slightly longer in the direction of the pipe, and at one end (left) there is an ofi'set flange or lip 3a similar to the bellshaped flange at the end of the ordinary pre-cast sewer pipe. The opposite end of the liner is plain, a joint or overlap being made with the forward end of an adjacent plate having the same lip 3a, the lap occurring on theoutside of the liners so that the inner surface is perfectly smooth.

The side edges f each plate are cast to provide square shoulders 36, 3b of a depth one-half the thickness of the liner and a width about twice the thickness. These shoulders, however, face in opposite directions, one outwardly and the other inwardly,

The shouldered side edges of each plate joins with plates on either side, the upwardly facing shoulder ofone overlapping or interfitting with the outwardly facing shoulder of r,

the next and so on, entirely around one circular row or course of-plates or liners as shown Figure 1. Each circular row of liners may not, however, register with those of the next, but may be preferably staggered so that the longitudinal joints between the liners of one circular course fall between the joints of the courses on either side, as'in Figure 2.

And, finally, each liner has one ormore holes 4 cored through it along'the'longitudinal center line. As shown (Figure '3), there are two of such holes provided, one being spacedinwardly from each end about one-fourth the length ofthe liner; On the inner face of the liner these holes are counter-sunk.

These liners are moulded or cast of clay and then fired in the same manner that pipe and other vitrified products are made, so

that their exterior surfaces present the same hard glazed finish common to such prodiu' o I The preferred method of constructing a pipe line, incorporating the liners, will be understood from the following: Two cylindric forms A and B of suitable length would be used, one'for the inside and the other for ofthe liners. These lugs have theshape of pins or bolts with a flat conical headat one end of a round shank, and are preferably made ofsome non-corrosive metal such as Monel metal (a nickel alloy) or other suitable material. The .holes in the liners are sized to receive the lugs with a snug fit, the

I. heads seating. flush in the countersunk recesses on the inner faces ofthe liners and the shank extending through and beyond the outer surfaces thereof, to be eventually embedded in the concrete outer shell or layer.

Consequently, the length of the lugs is governed by the distance they should extend into the concrete to provide a firm anchorage, and, if desired, notches may be formed 1 along the shank, as shown in Figure 4, to

increase the holding capacity ofthese lugs. Other modifications in the, lugs will be later noted. Y 3 3 Having erected the lining about the inner form with the lugs in place, the entire outer surface of .the lining 2 is then coated .or sprayed with a sealingcompound, such as 1 asphaltum, tar. or other suitable substance whichis not aflfected by the: destructive acid gases in the sewage This coating serves not only to fill in and seal the joints and crevices between liners and between the lugs and the holes, but provides an intermediate protective layerzfi between the inner lining and the outer body of concrete.

The lining having thus been erected and sealed, the outer form B is then placed aroundthe inner form and the concrete poured in the usual manner and allowed to set and harden. The forms, which would be-ofsectional design, are then removed and the same operation repeated for the next section of the pipe.

Thepipe so constructed would thus have an inner lining of'yitrified clay, an intermediate layer of sealing compound, and an outer shell or layer of concrete in which are firmly embedded the ends of the lugs which anchor the lining to the concrete structure of the pipe.

One of thechief advantages of this method of construction is the use of the separate lugs inserted through cored holes in the liners, as compared for instance, with ribs, beads, grooves orother anchoring devices cast on the outer face of the liners for the purpose of affording an anchorage in the concrete. In the manufacture of the liners, the ease of drawing them from the moulds determines the shape and arrangement of these integral anchoring devices. As a result, an anchoring projection which is suitable from a manufacturing standpoint is not generally practical in the construction of the sewer pipefon account of the difiiculty in obtaining a perfect anchorage in the iconcrete, due to the fact that in pouring the concrete it does not fill in completely around the projections, but leaves pockets or voids which weaken the pipe structure, this being particularly true where the projections extend longitudinally of the liners. With the use of the separate lugs, however, it is only necessary tocore holes through the plates, thereby materially simplifying the manufacture of the lining material. Again,-

the lugsmay be made of a material more suitable for anchoring purposes than that of the liner itself, such as metal, and their shape is such that the concrete readily flows between and around them so that they become firmly embedded. Moreover, separate anchoring members permit of variation in their length and shape, to meet different operating conditions. For'instance, the shanks of the lugs may be lengthened to extend I through the concrete shell, with their projecting ends 56 threaded to receive locking members or threaded extensions provided at both ends, as shown in dotted lines (Figure 4), andwhich can be used for supporting the formsif the contractor desires,

c Having set forth a preferred embodiment of my invention, I claim:

1. Asewer pipe comprising an outer shell .of 'cementitiousmaterial, a protective lining for the interior of said shell consisting of plate-like sections laid edge to edge, a layer'of a sealing compound interposed between said outer shell and lining and anchoring members inserted through holes in said plates and embedded injsaid shell.

2. A sewer pipe'comprising an outer shell of cementitious material, a relative thin intermediate layer of an initially plastic sealing compound and an inner lining consist- .ing of plates of a corrosion resistant material laid edge toedge and anchoring members adapted to be inserted through holes in said plates from the interior of said pipe fastened in said outer shell.

3. A sewer'pipe comprising an outer cylindric shell of relatively thick concrete, a thin layer of a non-corrosive sealing compound covering the inner surface of said shell, an inner lining consisting of thin plates of a vitreous substance joined edge to edge, and anchor members consisting of pins of non-corrosive material passing through holes in said plates with their shank portions embedded radially in said outer shell.

4. A sewer pipe comprising an outer cylindric shell of relatively thick concrete, a thin layer of a non-corrosive sealing compound covering the inner surface of said shell, an inner vitreous lining of relatively thin plates adapted to be laid edge to edge and having holes therethrough, and anchoring members consisting of pins of a non-corrosive metal adapted to be inserted through the holes in said plates from the inside of the pipe and their shank portions embedded in said outer shell.

Signed at Fort Dodge, Iowa, this 12th day of December, A. D. 1932.

CLARE H. CURRIE.

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