US1523021A - Centrifugal metal-pipe mold - Google Patents

Description

Jan. 13. 1925 1,523,021

' J. B. LADD CENTRIFUGAL METAL PIPE MOLD Original Fil d ly 12, 1922 2 Sheets-Shee l Br Wye ATTORNEY Jan. 13. 1925. 1,523,021

J. B. LADD CENTRIFUGAL METAL PIPE MOLD 0rigina1 Filed July 12, 1922 2 Sheets-Sheet 2 INVENTOH 7W I6.

ATTORNEY Patented Jan. 13, 1925.

STATES JAMES B. LADD, OF ARDMORE, PENNSYLVANIA, ASSIGNOR TO UNITED STATES CAST IRON PIPE & FOUNDRY COMPANY, OF BURLINGTON, NEW JERSEY, A CORPORA- TION OF NEW JERSEY.

CENTRIFUGALH METAL-PIPE- MOLD.

Application filed July 12, 1922, Serial No. 574,470. Renewed December 6, 1924.

To all whom it may concern:

Be it known that I, JAMES B. LADn, a citizen of the United States of America, and resident of Ardmore, in the county of Montgomery, in the State of Pennsylvania, have invented a certain new and useful Improvement in Centrifugal Metal-Pipe Molds, of which the following is a true and exact description, reference being had to the accompanying drawings, which form a part thereof.

My invention relates to metal pipe molds such as are generally used in the centrifugal casting of pipes. Such molds, which are cooled externally, usually by a water jacket, have their interior surface subjected to great strains by reason of the alternate heating and cooling of the inside of the mold during the operations of casting pipes, the inside of the mold being, at the time of pouring, exposed to the temperature of the molten iron while the outside of the mold remains at all times much cooler and, in the case of water cooled molds, at a temperature probably not exceeding 200 F. In another application filed by me, on the 12 July 1922 Serial No. 574,469 I have described and shown as a means for obviating or diminishing the destructive strains of the inside of the mold, the formation on said inside of the mold of a series of narrow slots or grooves of such width that the molten metal even under the pressure exerted by the rapid rotation of the mold, would not penetrate into the grooves, but which at the same time permit the segments into which the inside of the mold is divided to expand separately and thus avoid the great strains to which the uninterrupted surface of the mold would be subjected. My present invention has for its object to further improve molds provided with internal slots by so constructing them that they may be more easily cooled and so that the outer and cooler portion of the mold will offer less resistance to the expansion of the inner portion than has heretofore been the case. Primarily, my object is to provide for the air cooling of such a mold, but my new mold may also be advantageously used with water cooling. My invention consists, generally speaking, in constructing a mcldwith narrow slots formed on its inner surface and with transversely runningslots formed on its outer surface,

should extend close to the internal slots.

My invention will be best understood as described in connection with the drawings in which- Figure 1 is a sectional view of my improved mold.

Figure 2 is a cross section of the mold on an enlarged scale.

Figure 3 is an enlarged view of a section of the mold, as shown in Fig. 1.

Figure 4 is an enlarged view of a segment of the mold shown on the same section as Fig. 3.

Figure 5 is a view generally similar to Fig. 3, but showing a modification.

Figure 6 is a view showing another modification.

Figure 7 is a sectional view of a modification.

Figure 8, a cross section on line 88 of Fig. 7.

Figure 9 is an enlarged view of a section of the mold shown in Fig. 7 and Figure 10, a view showing a modification.

A, Fig. 1, indicates the mold, and B the ring at the smaller end of, the mold for forming the end of the pipe, and C the core at the other end of the mold for forming the bell, A indicating the enlarged end of the mold. Through the interior of the mold I form a series of symmetrically disposed longitudinal slots indicated at D, D, etc. These must be so narrow that the melted metal will not be forced into them when it is poured into the mold and for this purpose, should not much exceed two hundredths of an inch, and should be between one hundredth and two hundredths of an inch in width. These slots will permit the metal in the segments into which they divide the interior of the mold, to expand and contract without exposing the interior of the mold, as a whole, to destructive strains. E, E, etc. are circumferential slots which may be and should' be quite broad and which, when the mold is to be air cooled, may and should intersect the longitudinal slots D, as indicated til intersect the slots D, but be separated therefrom by a thin metal web, as indicated at G in Fig. 5. H

Instead of making the slots E parallel to each other as indicated in the other figures, these slots may consist of a helix 6, as indicated in Fig. 6.

In Figs. 7 to 10, the mold A is shown as having interior circumferential slots (Z and outer longitudinal slots e the slots intersecting each other inFigs. 7 8 and 9, and being separated by a thin metal shell 9 as shown in Fig. 10. This construction is obviously an equivalent, generally speaking, for the first described construction.

It is obvious that my-construction provides for an energetic cooling of the mold as the exterior slots increase the cooling surface and bring the cooling medium close to the pipe casting.

It is also obvious that my construction produces a mold that is free to ex and and contract, both longitudinally-an circumferentially, regardless of the difference in temperature of interior and exterior of the mold because the interior slots permit of free expansion and contraction ofthe in terior of the mold in one direction and the exterior slots permit free expansion in the other direction.

Having now described my invention, what I claim as new and desire to secure by Let ters Patent, is:

1. A centrifugal metallic pipe mold haring narrow slots in its inner face and transversely running slots in its outer surface.

2. A centrifugal metallic pipe mold having narrow slots in its inner face and transversely running slots in its outer surface extending inward to intersect the inner slots.

3. A centrifugal metallic pipe mold having longitudinal narrow'slot's in its inner face and circumferential slots in its outer surface.

4. A centrifugal metallic pipe mold having longitudinal narrow.slots in its inner face and circumferential slots in its outer surface extending inward to intersect the longitudinal slots.

' JAMES B. LADD.

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