US1195830A - James r - Google Patents

Description

La. MCWANE.

CAST IRON PIPE.

` APPLICATION FlLEA-D MAY I8, 1915.

' 1,195,830., y Patented Aug. 22,1916.

n -rArs Ar ricerca JAMES R. li/iCWANE. 0F BIRMINGHAM, ALABAMA.

CAST-IRON PIPE.

Liosso.

Specification of Letters Patent. Patented Aug. 22, 1916.

Appli-cation filed May l18, 1915. Serial No. 28,968.

To alloc/1.0m t may concern.'

Be it known that I, JAMES R. MCVANE,

citizen of the United States, residing ,at

Birmingham, in the county of Jefferson and State of Alabama, have invented a new and useful Cast-Iron Pipe, of which the following is a specification. v

This invention has reference to cast iron p ipe, and its object is \to provide a form of pipe wherein certain objections to standard cast iron pipel are overcome.

Standard castiron pipe is cast in upright molds in units of relatively great length with one end a spigot end and the other a bell end. Experience has shown that such pipes must be cast with walls of considerable thickness and oftentimes much thicker than is needed in service in order to yovercome the possibility of the development of defects which would render the pipe units useless for the purpose for which they are intended.

There is considerably more metal in the standard cast iron pipe unit than is necessary for many purposes, but the excess metal has been put into the castings because of the diiculty in makinga sound casting with less metal and because it has been found that a pipe made of lighter section is liable tobreak in handling.

On account of the difficulties in casting solid pipes in thin section even though the pressure to be withstood. would warrant such thin section, there hasbeen a very material waste in the employment of excess metal and in the payment of freight u'ponsuchy excess metal.

There are many purposes where cast iron pipe of much` lighter section than is customary could be used, provided suchpipes could be molded successfully, and could be y handled to the destination without breakage. The pressure in gas mains and in many water supply lines is a relatively very light pressure, and hence a light section would serve every purpose.

A cast iron pipe providing a pipcemploying very materially less metal than heretofore, and yet having an inherent strength resisting breakage, and meeting the conditions present in the casting of the pipes in upright to be necessary to avoid breakage. Between these ends and representing byk far the greater portion of the length of the pipe, the full thickness is continued in the form of longitudinal ribs of considerable circum ferential breadth, .and these ribs are joined by circumferential ribs, or by spiral or helical ribs of relatively short pitch, whereby a very material portion of the surface of the pipe betweenthe twoends is of reduced thicknessbetween the longitudinal and circumferential ribs, so that thereduced portions are in the form of panels. Such a pipe is especially adapted for casting in uprightmolds and for casting'in units of full length and integral throughout, and particularly does such a pipe avoid the troubles heretoinstances the construction has been such as molds, is realized by the present invention. Y

The improved pipe follows the lines of ordinary cast iron pipe in having a bell end and a spigot end, which may each be of a thickness throughout which experience has shown to preclude the successful casting thereof in upright molds for, reasons which will hereinafter appear. i

The invention will be best understood from al consideration of the following detailed description, taken vin connection with the accompanying drawings forming a part of this specification, with the further understanding that while the drawings show a practical form df the invention, the latter isnot confined to any strict conformity with the showing of the drawings` but may be changed and modified, so long as such changes and modifications mark no material departure from ythe salient features of the invention. l

In the drawings :-Figure l is an elevation of a pipe constructed in accordance with the invention with a portion of each end brokenaway to show the cross-sectional shape thereof. Fig. 2 is a transverse section of Fig. l through a set of panels, the showing of the figure being on a larger scale than Fig. l. Fig. 3 is an elevation of a fragment of the pipe showing a modified arrangement.

Referring to the drawings, and especially to Figs. 1 and 2, there is shown a pipe l such as is employed in gas andA waterfpipe lines, and such pipe has a spigot end 2 and a bell end 3 of standard form. Such pipes are one-piece structures,. and are made' of cast metal. The -mol'd employed is filled with the molten metal while the mold is in the upright position with the bell end down- 5, ward.

molded experience has shown that both' as a matter o f-strength and-to permit the casting of the pipes, the thickness of the metal of the walls of the pipe must reacha certain 1o amount., If the walls of the pipe be as thin as they might be for the service to which 'the pipe is put, then the -dropping of the hot metal poured into such thin vspace as would represent a thin walled pipe, scatters as it drops and is cooled off to such an extent that when it finally settles such cooled ofiI particles do not coalesce and the result is an imperfect casting and ,a leaky pipe. Moreover, a pipe as tliin as the service would 20 permit is liable to break at the spigot end during transportation. Should it happen that thereare any impurities in the molten metal they are liable to lodge in a. thin walled pipe' and cause a leak. Because of such conditions it is thelcustom to cast the pipe with thick enough walls to sufficiently strengthen the spigot end, which is the end liable to be broken, and to prevent the formation of what is known as cold shots due 80 to the scattering and cooling off of the metalk `.ff\...w`lien poured into a thin space from above,

or-tlie lodginent of impurities liable in thin Walled pipes to produce leaks. To overcome all these difficulties of casting and at the same time materially reduce `the weight of the pipewithout sacrifice of any of the advantages, the pipe is formed with a circular series of longitudinal ribs il extending from the spigot end 2 where the pipe is of' full vthickness all the way around, to the bell end 3 where the pipe is also of full 4thickness all the way around. The ribs 4l are likewise of full thickness andare joined at suitable intervals by transverse circumferential ribs 5 which in Fig. l are shown as perpendicular to the ribs 4, but these ribs may beotherwise arranged with relation to the longitudinal ribs 4, as, for instance, there may be generally circumferential ribs I 5 extending spirally or helically about the pipe, as in Fig. 3.

In either instance the spaces bounded by the longitudinal and transverse lribs have the walls much thinner, these spaces being in thevform of panels AG of suitable shape. The interior lof the pipe is smooth or unbroken throughout and of standard diaineter, while the exterior of the pipe` at the points corresponding to the spigot end 2, the bell end 3 and the ribs 4 and 5 or 5VIL are all'of a thickness-of wall which experience has taught meets the conditions of casting and strength. The thickness of theivalls of the panels 6, however, may be quite materilally less than that of the ribs and other As these pipes have been heretofore v niayfcoincide with the longitudinal ribs 4, which latter are represented fin the mold by 80 l channels of ample width and depth.

In the pouring rthe hot metal quickly gravitates to the lower end and then the level of the accumulating metal rises with the hot metal rapidly finding its way through the transverse 'channels and into the thin walled panels. The relatively vthick masses of metal accumulating inthe channels represented inthe spacesprovided for the formation. of the ribs 4 maintain the heat of the metal at suchhigh point that there is no scattering or formation of cold shots during the pouring operation. Moreover, in the event of there being any impurities in the metal being poured,.these impurities tend to accumulate in the channels corwherefore only pure metal finds its way into the thin walled parts representing the panels,V

so that these panels have their, walls perfect and hence the metal is 4solid and well knitted together, and leaks are less likely to occur.

Those parts of the mold corresponding to the ribs form channels througlrvvhich the hot metal is conducted in relatively thick masses and provide gates through which the molten iron is carried to the thin portions. The ribs not only lcontribute to the producsuch as represented in since for many purposes responding to the ribs of the finished pipe,

tion of a sound casting despite the thin walls of the panels, but also provide ample strength for `the casting and prevent breakage in handling. v Q 1 lVlien a cast iron pipe is broken in handling the break usually occuis at the spigot end which is the weak part. By carrying the ribs throughout the' length of the pipe to about withinsix inches of the spigot end and forming such spigot end of the same secltion as in any ordinary bell and spigot lcast iron pipe, such full or plain portion of full thickness serves to strengthen the pipe at.

the weak point, and it also furnishes a full, smooth surface for calking.

A cast iron pipe such a's shown in the drawing has all the strength for many Apurposes of a cast iron pipe of full thickness throughout, and, moreover, is materially lighter in weight, this representing a corresponding material saving in metal and a very material saving in transportation costs.

The improved pipe besides being excel-i1 lently suited for purposes where there'is internal pressure, is even better suited for use where the strain is external, as, for instance, in thecase of culverts. ABecause of the saving in metal and transportation costs cast iron pipes constructed can economically be used in placesoil other types of metal culverts, because castjiron has lasting Nualities when used underground which is not found in metal'culverts which haveonly the advantage 'over cast iron culw verts in the matter of lightness and cheapness, which advantages are in a large measure present in the improved pipe of this invention.

While it. has been heretofore proposed to produce pipes of short lengths longitudinally divided into sections l and provided with external ribs, the arrangement has been such as to prevent the formation of such sectional pipes in vertical molds, nor could such ribbed sectional pipe be cast of such light Weight as is provided by the pipe herein described with the great degree of strength and the uniform distribution thereof.

What is claimed is Ik' 1. A oneepiece cast iron pipe having end and body portions with the latter provided with external depressions forming'panels with walls of standard pipe of the same internal diameter, said panels being arranged to define on the exterior of the body portion of the pipe longitudinal ribs and inter-connecting lateral ribs, said ribs corresponding in thickness diametrically of the pipe to the thickness of the wall in standard cast iron pipe of the same internal dimensions, whereby the longitudinal rib-producing channels in the mold provide passageways for relatively thick masses Of molten metal during pouring and thereby prevent the formation of cold shots and at the same time segregate impurities, and whereby the weight of the pipe is lessened over that of standard pipe of the same dimensions by the reduction in thickness of the walls of the pipe at the panel portions. l

2. A one-piece cast iron pipe having end portions joined by longitudinal .relatively broad ribs with interconnecting relatively broad ribs joining the longitudinal ribs, said longitudinal and connecting ribs defining panels with the end portions ,of the pipe and the'ribs having a thickness corresponding to the thickness of wall of standard cast iron pipe of the same internal dimensions and the panel portions being of less thickness of wall than the ribs.

3. A onepiece cast iron pipe having spigot and bell portions of as herein "described,

of less thickness than the walls smooth exterior with longitudinal ribs disposed about the body of the pipe and connecting the end portions,` andflafterally extended ribs con necting the longitudinal ribs, the lateral and longitudinal ribs delining panels with the walls of the pipe at the ribsand at the Vspigot and bell portions of substantially equal thickness, and with the walls of the panel portions of less thickness than the lirst-named portions.' V

4. An elongated one-piece cast iron pipe having a circular series of substantially parallel longitudinal ribs on its exterior of a thickness of wall permitting the casting of the pipe in an uprightv mold and with thin walled portions between the ribs, whereby during the casting operation the channels in the molds in which the longitudinal ribs are formed provide passageways for relatively thick masses of molten metal segregating impurities and preventing the formation of cold shots, and also distributingv to the thin walled portions spending in thickness to the thickness ofl wall of standard cast iron pipe of the same internal dimensions and extending -Iboth longitudinally and laterally of the pipe to admit of the formation in a vertical mold of a light weight lpipe substantially free from materialimperfections dueto cold shots or impurities.

6. A onepiece cast iron pipe having on its exterior longitudinal ribs corresponding in diametric thickness to the thickness of wall of standardcast iron pipe of the same internal dimensions, said ribs being spaced about the pipe in accordance withthe spacing of and in alinement with the pouring gates of the mold in which the pipe is cast, whereby the channels in which the ribs are formed convey and distribute the metal to the portions of the mold between the ribforming channels and whereby the pipe is prevented from breakage in handling and under pressure.

In testimony, that I claim the foregoing as my` own, I have hereto aflixed my sig.-

Witnesses:

C. W. HENRY,

HARRY J. EARLY.

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