US1688727A - Cast-iron pipe - Google Patents

Description

1 u w u v m v H 1%: MWIIHPHIW J. R. MCWANE Oet. 23, 1928.

CAST IRON PIPE Filed Jan. 12, 1926 Patented @et. 23, 1928.

UNITED STATES JAMES R. MCWANE, OF BIRMINGHAM, ALABAMA.

CAST-IRON PIPE.

Application filed January 12, 1926. Serial No. 80,781.

This invention relates to cast iron pipes.

The object is to provide a cast iron pipe of adequate strength which maybe conveniently and economically used in many places where, at present, it is deemed necessary to use steel or wrought iron pipe, by reason of the fact that the latter has, heretofore, been more easily cut to length and threaded.

A full and complete understanding of the invention may be obtained from a consideration of the following detailed description, taken in connection with the accompanying drawing forming a part of this specification.

In the drawing, in which similar reference characters designate corresponding parts throughout the several figures z- Figure 1 is a plan view of the preferred form of the invention shown in duplicate or twin form in connection with the drag section of a horizontal pipe flask.

Figure 2 is a longitudinal section, drawn on a larger scale, of a short piece of pipe cut to a desired length from one end of one of the pipes shown in. Figure 1.

Figure 8 is a transverse sectional View taken on the line 33 of Figure 2.

Figure 4: is a plan view of a pair of twin pipes having a modified form.

One of the difficulties in the use of threaded cast iron pipe has been that the thickness of sectionmust be greater in the cast iron than in wrought iron or steel pipe on account of its brittleness. T0 overcome this it has been the practice of some engineers to use fittings of larger diameters for a given capacity of pipe than are used for wrought iron or steel pipe, but this expedient requires that either the entire wall thickness of the cast iron pipe must be increasechor at the ends where the threading is done, the diameter must be enlarged on the outside, for it must be borne in mind that the bore of the pipe should be smooth and uninterrupted.

Heretofore it has not been found practicable to make a small cast iron pipe in quantities, in the usual, vertical method of casting without excessive cost. However, my experience has shown that the smaller pipes, such as service pipes, etc., may be cast expeditiously and advantageously, in twin form and in great quantities, by using the horizontal method with green sand molds and green sand cores, and by allowing the molten metal to enter the molds through a plurality of gates, spaced apart throughout the length of the pipes. In breaking off these gates from the twin pipes, often small portions in or beyond the surface of the pipe are broken. Besides, there is always danger of shrinkage, or the presence of sand holes at these places, which, though not necessarily causing leakage of the pipe or seriously impairing its strength, makes for imperfect threads, which may result in a leak after the pipe has been in use for some time, and which may prevent securing of two threaded sections because of an imperfection in the end of the thread.

A specific object is to provide a cast iron pipe that Vill take a perfect thread on its terminals, the pipe being of any desired length cut from the full length pipe, without weakening caused by cutting the thread, and at the same time to provide a pipe wherein the breaking off of the gates will not in any way affect such threads.

Referring to Figure 1 of the drawing there is shown the lower section or drag 1 of a pipe flask used in horizontal casting, and the usual sand mold 2 formed therein to be used in the usual manner with a corresponding cope, not shown. The usual, continuous sand cores 3 carried by core bars 4 are supported by their ends at each end of the drag, said molds and cores being arranged parallel to each other and in the same horizontal plane. The cores and molds are preferably made of green sand, and to form the twin pipes, as shown, the molten metal is poured from a multiple lip ladle into 7 a corresponding number of sprue holes formed in the sand of the-cope, thence flowing into gates 5 having branch connections 6 at either side, and into the spaces left to mold the two pipes 7.

In the preferred form of the invention, as illustrated in Figure 1,'each pipe is provided, at either side of the transverse center line, indicated at c, with an equal number of uniformly spaced, circumferential enlargements 8 extending for the entire length of the same.

The center enlargement 9 is somewhat longer, longitudinally of the pipe, than the other enlargements 8, and the same is located with considerably more of its length to one side of said center than to the other, so that the said enlar ements 8 of one series are differently spaced relative to the center line 0 than the other series. Since the lengths of all of the enlargements 8 are the same, this arrangement causes one terminal enlargement 10, to be somewhat longer than the interme diate enlargements 8, and, at the same time, causes the other terminal enlargement 11 to be somewhat shorter, as clearly shown in Figure 1. The enlargements 8, 9, l0 and 11 are all of the same thickness and are cast as integral bands or collars, increasing the diameter and hence strengthening the pipe at these points and providing added material for cutting a terminal thread on any one of the en largements.

The reduced portions 12 between each of the bands or collars preferably have the normal thickness of an ordinary cast iron pipe of this character, said portions 12 being all of the same length or width and coinciding with the aforesaid branch connections 6 of the gates 55. The molds are each provided with a suitable opening opposite each of the reduced, annular portions 12 of each pipe 7, to form, when the molten metal enters, a longitudinally disposed web or boss-13 joining the inner side of each pipe, and each band or collar defining the same, and having connection with a branch of the gate, which latter maybe safely broken off without weakening the side of the reduced portion 12 having the thickness of a normal pipe.

With this arrangement it will be seen that a pipe of any desired length may be cut from the original. pipe, even to the fractional part of feet and inches, for if, by measuring from one end of the pipe it is found that a pipe of the desired length terminates with one of the reduced portions 12, it is only necessary to reverse the pipe or measure from the other end, when it will be found that the desired length will terminate at one of the intermediate bands or collars 8 or opposite the central band or collar 9, when the pipe may be severed and the terminals threaded, as indicated at 14 in Figure 2. From this figure it will be seen that the threads may be safety cut into the greater diameter of the bands or collars without weakening the pipe. By the provision of the aforesaid webs or bosses 13, the branch arms of the gates may be safely broken off, even though said break may extend somewhat into the wall of the metal, as shown in said figure.

Atconsiderable saving of metal is effected by the provision of the spaced areas of increased thickness of the walls over a pipe having the entire length of the pipe of increased thickness. Another additional disadvantage of the latter form of construct-ion is that a measurement might terminate at one of the broken branches of the gate which would cause an imperfection in the thread and a workman would not think to reverse the pipe and measure from the other end. On the other hand the aforesaid spaced areas define perfectly threadable points and suggest the reversal of the pipe, when necessary, to bring the measurement opposite one of said areas, which is clear of imperfections.

In Figure 4 twin pipes are shown cast and joined together in the same. way, to have the gates broken from the same and to provide for fractional length pipes when necessary, though this form of the invention has the disadvantage that both pipes are necessary to provide any fractional length pipe. In other words, if the desired length may not be cut from one of the pipes, by reason of the meas urement terminating at one of the reduced portions, the said pipe may be produced from the other full-length pipe, for it will be ob served that the collar or enlargement 15 located at the center of one of the twin pipes is longer than the central enlargement 16 of the other pipe, and that the intermediate collars 17 of each pipe are thus arranged in staggered relation to each other and that the continuous series of equally spaced enlargements 17 extend, on each pipe, from the center to one end only. The gates have their branch connections joined to the reduced portions of each pipe throughout their lengths, and the plain ends of the pipes 7, of normal thickness, have their ends provided with terminal collars 18, with one or more of the intermediate collars or enlargements 17 formed upon the same.

If a sectional pipe of greater length than half of the original pipe is desired, the same may be out from either of the pipes of the twin formation, shown in Figure 1 of the drawing, as the preferred form of the invention, by measuring from one end or the other, as above described, and the sameis true in the case ofa relatively short pipe of less than half the length of the original pipe, as will be clearly understood. In the secondary form, shown in Figure 4, the desired sectional pipe of more than half the length of the original may be cut from one or the other of the twin pipes by including the plain half of that pipe, and the short pipe may be secured from that end of one pipe or the other having the continuous series of enlargements formed thereon, so that it is necessary to have both of the pipes of the latter form on hand in order to secure any desired length of sectional pipe within the limits imposed by the standard pipe length. r r

From the foregoing it will be seen that a simple structural change has been made in cast iron pipe, which will enable users to obtain fractional pipe of any desired length, each terminal of the latter being provided with an exterior, annular enlargement with out imperfections for receiving threads which may be out without weakening the pipe, the broken gates, no matter what the length of the fractional pipe may be, being spaced from the point where the threads are cut. The improved construction renders cast iron pipe practicable for service in many places where only steel or wrought iron pipe has heretofore been used, with the resulting longer life of the pipe system afforded by the cast iron product.

Inn

Obviously the invention is capable of being embodied in several forms.

What is claimed is 1. A cast iron pipe section having exterior circumferential enlargements adapted for threading, said enlargements being spaced apart and extending from one end to the longitudinal center of the pipe section; and a similar enlargement formed at the other end; all the enlargements being formed without weakening the pipe, which is of standard thickness at its thinnest portions.

2. A cast iron pipe section having walls of standard thickness, spaced bands or enlarge ments cast integrally on the exterior of the pipe, said enlargements being of uniform thickness and length, the series extending from one end substantially to the center of the pipe, and a similar band or enlargement formed at the other end of the pipe section but of a different length from that of the band at the end first mentioned.

3. A cast iron pipe section having walls of standard thickness, spaced bands or enlargements cast integrally on the exterior of the pipe and of uniform thickness, the length of of each enlargement being greater than the space between two adjacent enlargements; all the enlargements being formed without weakening the pipe, which is of standard thickness at its thinnest portions.

4. A cast iron pipe section having spaced circumferential enlargements cast integrally on the exterior for being threaded, said enlargements extending from one end to the center of the section and being of uniform length except the terminal enlargements and the enlargement at said center, which is long or than the others.

5. A cast iron pipe section having integrally formed bands or collars on the exterior thereof .and spaced apart from end to end of the same, the band or collar at the center of the pipe being longer than the others, and the band or collar at one end of the pipe section being longer than that at the other end.

6. A cast iron pipe section having integrally formed, spaced bands or collars on the exterior thereof and extending from end to end of the same, the band at the center of the series extending more to one side of the longitudinal center of the pipe than to the other.

7. A cast iron pipe having exterior bands formed integrally thereon, each band being equally spaced apart, the series of bands extending from end to end of the pipe, the central band of the series being longer than all the rest and located nearer to one end of the pipe than the other, all the intermediate bands being of uniform length, and one terminal band being longer and the other terminal band shorter than the intermediate bands.

8. A cast iron pipe having walls of normal thickness and provided with external reinforcing bands cast integrally therewith, said bands being spaced apart, and a series of longitudinally disposed bosses formed on the pipe betwen each pair of bands and joined to the latter at its ends, said bosses having connection with the pouring gate or gates, so that the latter may be broken off without weakening the pipe. I

9. A cast iron pipe having walls of normal thickness and a bore or passageway of uniform diameter, a series of spaced, circumferential bands or collars on the exterior of the pipe and formed integrally therewith, the series at one side of the center being staggered with those at the other side relative to the center to enable the pipe to be cut through one or the other of the bands or collars to yield a shorter pipe of any given length Within the limits of the original pipe, the enlarged terminals of said shorter pipe being adapted to be threaded Without weakening the pipe.

10. Cast iron pipes adapted to be cast horizontally in pairs and having spaced bands or enlargements formed integrally around the exterior thereof, longitudinally alinged bosses formed on the pipes between the bands and joined to the latter, saidbosses having connection with a common gate to permitthe latter to be broken off Without breaking or weakening the pipe.

11. A cast iron pipe having its normal thickness of wall increased at intervals on the exterior thereof by spaced bands cast integrally therewith, said bands at'one side of the center being differentially spaced compared with those of the other side, so that the pipe may be cut through one of the bands in one series or the other to produce a. pipe of the desired length having an enlarged terminal at each end for threading.

In testimony, that I claim the foregoing as my own, I have hereto affixed nay-signature.

JAMES R. MoWANE.

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