Poillon v. Schmidt

37 How. Pr. 77
CourtUnited States Circuit Court
DecidedFebruary 15, 1869
StatusPublished

This text of 37 How. Pr. 77 (Poillon v. Schmidt) is published on Counsel Stack Legal Research, covering United States Circuit Court primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Poillon v. Schmidt, 37 How. Pr. 77 (uscirct 1869).

Opinion

Blatchford, J.

This is an action at law, for the infringement of letters patent, granted to thé plaintiff on the 21st of July, LS-57, for a new and useful “means” for rendering joints steam-tight.

The invention was made by William S. Gale, and assigned to the plaintiff.

The specification speaks of the invention as u a substitute for all known means of packing pistons or other steam joints.” It consists of a grooved or a corrugated surface with an opposing smooth or plain surface. The grooves may be made in the surface ot the piston or in the interior surface of the clyinder as preferred. The specification describes as follows, the working of the structure :

The steam as it is let into the cylinder, rushes in between the piston and cylinder, and fills up the grooves and the intervening space, between the piston and cylinder, where it practically forms a complete packing.

The steam which fills the grooves and intervenes between the piston and cylinder, also acts as a cushion to practically relieve the piston and cylinder from contact and friction. The grooves may be one or many, at more or less distance apart, more or less wide or deep, and they may be perpendicular or more or less oblique to the moving surface and of any sectional form. The best method is to groove one moving surface and leave the opposing surface smooth,to make the grooves thin and frequent, and the corresponding ribs or flanges of the same or about the same thickness as the width of the grooves. The grooves need not be deep, from one-quarter to one-half inch will answer. The piston can be of any ordinary size and dimension now in use or a trifle larger. It should fit easy, and does not require to be in actual contact with the cylinder. To cut the grooves perpendicular to the axis of the joint or to the moving surface, and in the sectional form of a parallelogram is the better way, and sufficient for all purposes, and is the most simple and cheap in construction. See representation in the acompanying [82]*82drawing. It will be apparent that my grooves and intervening ribs may be used on any joint between two surfaces subject to the operation of steam under pressure, to cause steam to become self packing. The particular point of my invention and discovery, and its importance will be perceived from the following: Since the introduction of steam as a motive power, it has always been supposed that two contiguous surfaces could only be rendered steam-tight by actual contact. Hence, every steam engine that has heretofore been made has depended upon smooth surfaces in contact, or else upon some character of elastic packing, that would set steam-tight against its adjacent surface. To accomplish this, great varieties of metallic and other packings have been devised and vast expenses incurred to make the pistons and other moving joints steam-tight, and this course has heretofore been universally pursued. I believe myself therefore, to be the original and first inventor or discoverer of the fact that steam when introduced into small grooves is one of the contiguous surfaces will itself form a packing, within said surfaces actually being in contact. I, however,wish it to be understood, that I do not claim the grooved surfaces in themselves, as these have heretofore been used for other purposes and have been used in connection with air engines. The claim is to “the method herein described of causing steam to become a packing to itself in steam cylinders or other parts of steam machinery by allowing the .steam to act in one or more grooves substantially as specified.” The case has been tried before the court wúthout a jury-

If the patent be valid the infringement is not denied. The defense is put upon the ground of a want of novelty in the invention; what is adduced to defeat the patent is a publication in aworkin german,called the “Schauplatz” published at Weimar,in Grennany,in 1847. The text of the publication is accompanied by a drawring and is this, as translated.” Mr. Cave uses for his blowing machines a very ingeniously [83]*83arranged piston, whereby the leather packing becomes unnecessary, which is perfectly air-tight, has no friction, does nor become heated, and requires no cost for keeping it in order.

This piston consists of a hollow cast iron ring, which has a diameter about two or three millimetus less than the cylinder, and whose outer surface has the greatest practicable number of annular and squares, depressions a, b, c, d. If now, for example, a piston arranged in this way goes upward and compresses the air which is found above it, and then this air, in part, presses in between the walls of the cylinder and the outer wall of the piston, having reached a, it freely expands, so that it compresses the air therein contained, and then loses for once a part of the force by which it had been pressed in, by which its motion is hindered, and there is opposed to it on the other side to which it tends to go, a certain resistance. It follows from this, that the air passed into ct, works backward one after another, into the grooves b, c, d, with a force which constantly decreases, and which for a sufficient number of grooves can become zero. Therefore, theoretically considered, the number of grooves must stand in direct proportion to the pressure. Mr. Cave, has employed these pistons for very many blowing cylinders, and even too for one, of three metres in diameter. He has made careful experiments with this contrivance, and the results obtained agree in all respects with the theory; an essential condition for the employment of this piston is a jierfect cirtricity of the cylinder a condition which we can now easily obtain by means of the vertical boring machine.

The first question to be decided is, wdiat is the proper construction of the plaintiffs patent, if it claims merely arrangement of the grooves in one of the two surfaces? If one be a moving surface, then undoubtedly the arrangement of Mr. Cave, is an answer to the patent, but the specification says that the inventor does not claim ‘‘the grooved surfaces in themselves.” Nor does he claim the use of the grooved [84]*84surfaces in . connection with air, for the specification states that they have been used in connection with air engines. The inventor, from the language of the specification, may fairly be said to have had in view the explanations of Cave, which used grooved surfaces in an air engine. He .puts his invention however, upon an entirely different point, and claims that notwithstanding Cave, he has made a patentable invention; he says that he has discovered the fact that steam may be made to pack'in and of itself, or to become what he calls ‘‘self-packing;” that prior to his invention it had always been supposed that ever since steam has been introduced as a motive power, that two contiguous surfaces could be rendered steam-tight only by actual contact; that consequently all steam engines had depended for steam-tight moving joints on the contact of smooth surfaces or on elastic packing set steam-tight against its adjacent surface; that in carrying out this idea great varities of packing had been devised at great expense, and that he first discovered the fact, that steam when introduced into small grooves in one of two contiguous surfaces, will itself form a packing without the surfaces being in actual contact. It was not attempted to be shown on the part of defense that these allegations of the specification are not true, otherwise than by introducing the description and drawing of the Cave apparatus.

But it was insisted that air, the elastic fluid used in the

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Bluebook (online)
37 How. Pr. 77, Counsel Stack Legal Research, https://law.counselstack.com/opinion/poillon-v-schmidt-uscirct-1869.