Kahnweiler's Pipe Joint

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


In the usual method ef forming joints for tubes for the conveyance of gas, water, or steam, great difficulty is experienced in first making them perfectly tight, and subsequently keeping them so, and enabling them to be easily turned to the positions desired. The object of the plan of joint, which we illustrate below, is to remedy the defects of the old mode of connecting swivel elbow joints, and figure 1 of the engraving represents a section through a gas or other pipe, to which the improvement is attached; figure 2 is a detached view of the open end of ditto, and figure 3 is a perspective view of the metal washer surrounding the bolt for securing the elbow to the pipe. Upon the end of a male section, A, of a joint, is cast an axial stem or rod, B, said stem projecting from a cross bar, C, which is cast with, and just within, the open end of the said section. This rod passes through the axis of the female section, E, of the joint, and through an aperture on the covered end of section E, beyond which it projects sufficiently to admit the' washers and tightening nut, D, which is screwed on its end, one of the wash- ers being of vulcanized india rubber, and the other of metal, of the shape indicated in figure 3, to fit the axial stem, which is squared on one side at this point, to prevent the washer from turning round when the joint is turned or swivelled. The face of the flansre, G, is left rough, as it comes from the mould, and the faces of the female section axe turned, so that very little work is required to make a joint of this kind air or water tight. A seg-mental pipe, H, extends from the female section, E, and communicates with another female section, arranged at right angles to the first mentioned one, and having a male section, I, attached to its open end by a rod or stem, J, and washers and nut, K, in the precise manner that the corresponding parts below are formed and fastened. Two washers, one of rubber and the other of leather, are placed between the flanges of the male and female sections of the joints, and the requisite degree of pressure to perfect the joints is given them by the tightening nuts, D, K. In this simple manner—a correct, reliable and efficacious universal joint is formed, capable of being easily moved in any direction, and without the expensive and difficult process in forming the usual conical joints heretofore employed. The patent was issued on the 29th of June, 1858, and any further information can be obtained by addressing the patentee, David Kahnweiler, 55 North 6th St., Philadelphia.

Scientific American Magazine Vol 13 Issue 51This article was published with the title “Kahnweiler's Pipe Joint” in Scientific American Magazine Vol. 13 No. 51 (), p. 404
doi:10.1038/scientificamerican08281858-404

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe