Pickering v. McCullough

• Decision Date: 01 October 1881
• Citation: 26 L.Ed. 749,104 U.S. 310
• Parties: PICKERING v. MCCULLOUGH
• Court: U.S. Supreme Court

104 U.S. 310

104 U.S. 310

26 L.Ed. 749

PICKERING v. MCCULLOUGH.

October Term, 1881

APPEAL from the Circuit Court of the United States for the Western District of Pennsylvania.

The facts are stated in the opinion of the court.

Mr. James E. Maynadier for the appellants.

Mr. William Bakewell, contra.

MR. JUSTICE MATTHEWS delivered the opinion of the court.

This is a bill in equity, filed by the appellants, to restrain the appellees from infringing reissued letters-patent No. 6166, dated Dec. 8, 1874, to George Nimmo, for an improvement in moulding crucibles, and for an account, the patent having been reissued to the complainants as assignees of Nimmo, the inventor and original patentee.

The original patent, No. 49,140, granted to him, bears dated Aug. 1, 1865.

The subject of the alleged invention is an improvement in the manufacture of moulding crucibles and pots, made of a plastic material, composed of plumbago, or so-called black-lead and fire-clay, used principally in the manufacture of steel. They were formerly made by hand, on a common potter's wheel, the hand and eye of the skilled workman building them up in the desired shape, as the material revolved upon the wheel. It is recited in the original patent to Nimmo that they had also been made in a mould, by a pressing instrument, for which reference is made to letters-patent, granted Oct. 26, 1852, to John Akrill. It is stated also by Nimmo, in the specification to his original patent, that 'difficulty has heretofore been experienced in removing the crucibles from the mould, in consequence of the adhesive nature of the black-lead compound or mixture employed for such crucibles. The amount of water, also, that is required to make the mixture sufficiently plastic causes the material frequently to crack and break in shrinking as it dries.'

The following is the description of the invention, as contained in the specification, referring to the drawing accompanying it:——

'The nature of my said invention consists in the manufacture of crucibles in a plaster mould, which gives shape to the pot externally and absorbs the moisture from the pot, causing it to dry uniformly and at the same time shrink away from the mould, preventing the air acting on the outside of the pot until after the moisture has been mostly absorbed, and prevents the pot from splitting or cracking from unequal contraction in drying. I mount my plaster mould in a revolving chuck, and employ a rib attached to a lever for spreading the plastic crucible material on the inside of the mould, and at the same time hardening, consolidating, and polishing the crucible on the inside by means of said rib.

'In the drawings is a bed carrying the vertical spindle, on the upper end of which is the hollow chuck, into which the plaster mould fits, and these parts are revolved by a belt to a wheel and crank, or by any other competent means. Near the chuck is an upright frame, with rollers over which the chain or rope passes, on one end of which is the counter-weight, and on the other the lever, having a handle at one end and carrying the rib. This lever is guided by the upright frame, and when not in use is drawn up by the weight. The crucible material is placed in the plaster mould, and partially spread by hand or by a conical muller. The back end of the lever is then brought beneath the stop or fulcrum, and pressed down until the lever takes a stop. The rib on the lever smooths, compresses, hardens, and polishes the interior of the mould, forming a perfect crucible, possessing great strength and beauty. At the same time there is great uniformity in the crucibles made in this manner. The crucible and mould are to be lifted off the chuck, and another mould introduced in the chuck, and the operation repeated.

'The crucible and mould are set aside. When the plaster of the mould has absorbed the moisture from the crucible, and the crucible has contracted away from the mould, and become sufficiently dry to be exposed to the air without risk of cracking, the crucible is to be removed and dried in any usual manner, and may be baked or burned.'

The claims are as follows:——

'What I claim and desire to secure by letters-patent is,——

'1. Manufacturing crucibles in a plaster mould, in the manner and for the purposes specified.

'2. Lever l and rib n, applied in the manner specified to form the interior of a crucible contained within a revolving mould, as set forth.

'3. The combination of the revolving chuck c, plaster mould d, lever l, and rib n, as and for the purposes specified.

'4. Mounting the lever l and rib n in the frame g in the manner specified, in combination with the counterpoise k, fulcrum o, and stop p, for determining the size of the interior of the crucible, as specified.'

It is conceded by counsel for the appellants that the claims in this patent were invalid, as being too broad, and that it was for this reason, and for a more definite and limited description of the real invention intended to be claimed, that it was surrendered and reissued.

The state of the art, at the date of his original patent, is described by Nimmo in the reissue, as follows:——

'Long prior to said Nimmo's invention the mode of manufacturing certain articles of pottery by means of a rib or former to give the desired shape to the inside of the article, and a revolving plaster vessel to properly present the 'ball' (as the lump of tempered clay is called) to and support it under the action of the rib, was well known; but this mode of manufacture was not applicable in the manufacture of crucibles, because the crucible would be injured or destroyed the crucile would be injured or destroyed in removing the rib, by the end of the rib striking the upper part of the crucible, as will be plain to all skilled in the art of crucible-making, and acquainted with the mode of manufacture above referred to.

'Another mode of manufacturing certain articles of pottery-ware by means of a rib or former for the inside of the article, and a revolving table (a common potter's wheel) which partially presented the ball to and supported it under the action of the rib, the workman using his hands to aid in presenting the ball to and supporting it under the action of the rib, is described in a French work published in 1857, entitled 'Lecons de C eramique,' par M. A. Salvetat, volume second, pages 121-2. This last-named mode of manufacture was applicable to the manufacture of crucibles, the apparatus being such that the rib was guided so as to cause it to approach the axis of the pot, where it was necessary that it should do so in order to prevent injury to the pot; but, even if useful at all in that manufacture, it is without doubt very much inferior to the mode of manufacture invented by Nimmo, and hereinafter described, the distinguishing difference between them being that the ball is presented to the rib and supported under its action, not by a flat revolving metal disk, but by a vessel made of plaster, which takes the place of both the flat revolving disk and the workman's hands, performing all the functions performed by this disk and the hands of the workman, but in a much more perfect manner and in less time.

'The invention of said Nimmo is, in fact, an improvement on the mode of manufacture, as well as on the apparatus, described in Salvetat's work, the improvement consisting in the different mode of presenting and supporting the ball; but we do not wish to be understood as claiming this mode of presenting and supporting the ball as the invention of said Nimmo, as his improved mode of manufacture is new solely because it is, as a whole, substantially different from the mode described by Salvetat, and from the mode first above referred to; indeed, as a short general description of Nimmo's improved mode, it may...