US214076A - Improvement in screw-threaded pipe joints and couplings - Google Patents

Description

W. O. ALLISON. Screw-Threaded Pipe Joint and Coupling.

No. 214,076. Patented April 8,1879.

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WILLIAM G. ALLISON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO W. O. ALLISON & 00., OF SAME PLACE.

IMPROVEMENT IN SCREW-THREADED PIPE JOINTS AND COUPLINGS.

Specification forming part of Letters Patent No. 2l4.0 76, dated April 8, 1879; application filed February 8, 1879.

To all whom it may concern:

Be it known that I, WILLIAM C. ALLISON,

, finished section of screwthreaded pipe constructed according to my invention; Fig. 2, a similar view of the same prior to the burnishing of the thread, and Fig. 3 an elevation of a coupling constructed according to my invention.

Similar letters of reference indicate corresponding parts wherever used.

This invention relates to galvanized or metalizioated screw-threaded pipe joints and coupngs.

As heretofore manufactured, galvanized pipe and such articles of kindred character as embody in their construction screw-threads have in their makingbeen first galvanized and subsequently cut with threads, the effect of which has been that the threaded portions have been divested of the galvanic coating, with the result that when a portion of the thread is exposed, as in Fig. 3, it is subject to all the evil results common to ungalvanized screwthreads.

The object of my invention is the making of galvanized, coppered, or other metal-coated screw-threaded pipe joints and couplings evenly coated in all portions, to which end it consists, substantially, as follows: The pipe joint or coupling which is to be galvanized or metal-coated is first threaded in the usual manner, the thread cutting being completed before the galvanizing or metal-coating process is commenced. The threaded pipe or socket is then subjected to the galvanizing or metal-coating operation until completely coated, after which the thread-cut portions are burnished down even by any suitable device as, for instance, by a burnisher of analogous construction and operation to the thread-cutting mechanism.

It will be understood that in the use of copper and some other metals it may not be necessary to burnish or recut the metal-coated thread, said thread being of suflicient ev'eir ness and smoothness to dispense with such burnishin g or recuttin g process.

Such being my invention, it is obvious that this invention provides a joint of greater ti ghtness than it has been practicable heretofore to produce, for the reason that an intermediate layer of soft metal is placed between the screwthreaded contact surfaces of the pipe joint or coupling, which forms a cushion or packing, with the result stated, and also that, all portions being alike galvanized, the pipe is not at any point exposed to corrosive or other such destructive influence, as has heretofore been the case.

Having thus described my invention, I claim and desire to secure by Letters Patentof the United States- 1. As a new article of manufacture, a screwthreaded pipe joint or coupling, the threaded surfaces of which are provided with a zinc or other metal coating to form a packing between the contact surfaces of said joint.

2. The herein-described process of making galvanized or metal -coated screw threaded pipe joints or couplings, which consists in cutting the screw-thread upon such pipe or coupling, then galvanizing or metal-coating the cut screw, and finally burnishing or recutting the metal-coated threads, snbstantiall y I as shown and described.

In testimony whereof Ihave hereunto signed In presence of- J. BONSALL TAYLOR, J onn J OLLEY, Jr.

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