Vapor Blast Mfg. Co. v. Pangborn Corp.

93 F. Supp. 792, 87 U.S.P.Q. (BNA) 65, 1950 U.S. Dist. LEXIS 2413
CourtDistrict Court, D. Maryland
DecidedSeptember 29, 1950
DocketCiv. A. No. 4459
StatusPublished
Cited by2 cases

This text of 93 F. Supp. 792 (Vapor Blast Mfg. Co. v. Pangborn Corp.) is published on Counsel Stack Legal Research, covering District Court, D. Maryland primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Vapor Blast Mfg. Co. v. Pangborn Corp., 93 F. Supp. 792, 87 U.S.P.Q. (BNA) 65, 1950 U.S. Dist. LEXIS 2413 (D. Md. 1950).

Opinion

COLEMAN, Chief Judge.

This is a patent suit involving the use of fluid-borne abrasives to finish or polish surfaces of metals, with particular relation to polishing with such accuracy as to produce highly finished surfaces on parts having a very minute tolerance. There is only one patent involved. No. 2,462,480-, issued February 22, 1949, to Arthur H. Eppler, on application dated January 8, 1944. While the patent embraces 21 claims, only two, Nos. IS -and 21, are in suit, the former being a method and the latter an -apparatus claim. One of the plaintiffs is the patentee and the other, Vapor Blast Manufacturing Company, a Wisconsin corporation having its principal place of business in MiL waukee, is a licensee under the patent. The defendant, Pangborn Corporation, is a Maryland corporation having its principal place of business in Hagerstown, Maryland. To the charge of infringement it defends with a denial, and also with the charge that the patent is invalid because (1) anticipated by the. prior art and (2) the two claims in suit are not sufficiently definite.

[794]*794What is claimed for the patent may best be indicated by quoting the following from the patent specifications:

“A primary abject of the invention is to use fluid-borne abrasives to finish or polish surfaces and to be able to control the finishing and polishing operation with such accuracy as to be able to produce a highly finished surface on parts having the most minute tolerances.
“Another object of the invention is to provide a new type of satin finish on metals, which has important advantages for bearings, and other purposes. In bearings the improved finish produced according to the method hereinafter to be disclosed holds an oil film in the bearing more satisfactorily than any other type of finish. Moreover, the finish has advantages quite apart from bearings in that it is very attractive and is rust resistant, and shows an increase amounting to as much as five to ten percent in tensile strength as • compared with the same parts finished ¡by other methods.
“An important object of the invention lies- in the fact that the wide control possible in its use permits of every type of operation from the coarsest rough or deburring cut to the finish honing or polishing. As will ¡hereinafter be more fully explained, the results achieved result from a novel method and apparatus using the abrasive in suspension in a liquid. I am able to deliver up to four to six times as much weight of abrasive material per minute as in any previous fluid-borne abrasive apparatus, at the same time controlling results so effectively as to be able to finish' ¡the most delicate parts.
“The abrasive comprises a liquid carrier having the abrasive material in suspension. In the past, liquids have been used as carriers for abrasive material, but in general the abrasives have been introduced into the carrier at the nozzle, and in no instance has the abrasive been in suspension in the carrier. ,
“In the sand blasting art the finest abrasive capable of effective use in an air blast has been of the order of 80 mesh, and all attempts to use a liquid vehicle or carrier for abrasives have involved the use of the same sorts of abrasives generally used in pneumatic sand blasting -apparatus. I have discovered that by using finer abrasives or by using emulsifying agents, or by both of these procedures, I am able to maintain the abrasive in suspension so that with the entire mass of emulsion in constant circulation I am able to assure a substantially uniform distribution of the abrasive throughout the liquid vehicle.
“For the high degree of polishing, which is one of the outstanding achievements of the invention, the finenesi of the abrasive exceeds anything previously thought usable in this art. As -above pointed out, 80 mesh abrasive is the finest ordinarily used in sand blasting. The finest abrasives available on the market for use in-lapping compounds and such other fine polishing work are about 650 to 700 mesh. This is the approximate fineness of talcum powder. The abrasives which-1 use in the practice of the present invention range all the way from 100 tO' 2500 mesh, the latter comprising -an impalpable powder. The- preferred range of sizes is from approximately 200- mesh to approximately 1300 mesh.
“The liquid vehicle is preferably water with chemicals added. In the apparatus disclosed I may, for ordinary work, use 50 pounds of abrasive -in a dry state to 50 pounds of the aqueous vehicle. To the water I preferably add a rust inhibiting chemical, such as the product commercially known aS' Metrolux, which 'contains trisodium phosphate, sodium chromate, and a form of lime which contains boron.”

The two claims in suit read as follows: “No. 15 (the method claim). A method of cleaning and polishing which comprises the suspension of a predetermined amount of abrasive particles in a predetermined amount of carrier liquid, circulating the liquid suspension of abrasive particles upon a predetermined path while maintaining the portions of liquid and abrasive approximately constant and maintaining the distribution of the abrasive approximately constant throughout the carrier liquid, and jetting portions of the circulating carrier liquid and abrasive against the surface to be cleaned or polished.” No. 21 (the ap[795]*795paratas claim) : “Polishing apparatus comprising a charge of liquid carrier and abrasive particles in suspension therein in approximately fixed proportions, a collecting sump, a work support above the sump from which portions of the treating charge will drain into the sump, a nozzle, an air supply connection to the nozzle, an emulsion supply for said nozzle including a circulatory system leading from and returning to said sump and intermediately in communication with the nozzle and means for pumping the said oharge through the system to supply the nozzle with portions of the charge under pressure.”

The method and apparatus called for by the above claims are obviously so interwoven that while the language of the two claims differs, it is appropriate to consider them together. And while the language in both claims may prima facie appear to involve a device that is rather complicated in construction and operation, when the technical phraseology is translated into more simple language neither apparatus nor method is actually complicated. . Thus, what is called for by these claims may be more simply stated as follows: (1) a metal sump tank in which is placed in liquid suspension a predetermined amount of abrasive particles; (2) a circulatory, system whereby this emulsion is pumped from the bottom of the sump tank through a pipe to a so-called supply tank above the top of the sump tank; two outlets from this supply tank, one leading from inside the lower portion of it, in the form of a supply line and referred to as the secondary circulation line, at the end of which is a nozzle supplied with a compressed air line through Which the emulsion may be ejected, under pressure as desired, against the articles to be aibraided and polished; and another outlet in the form, of an overflow pipe, and referred to as the primary circulation line which extends from the supply tank into, the lower part of the sump dank and through which the emulsion flows, by gravity, from the former to the latter tank.

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Related

Pennsylvania Crusher Co. v. Bethlehem Steel Co.
95 F. Supp. 696 (W.D. Pennsylvania, 1951)
Vapor Blast Mfg. Co. v. Pangborn Corporation
186 F.2d 230 (Fourth Circuit, 1950)

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Bluebook (online)
93 F. Supp. 792, 87 U.S.P.Q. (BNA) 65, 1950 U.S. Dist. LEXIS 2413, Counsel Stack Legal Research, https://law.counselstack.com/opinion/vapor-blast-mfg-co-v-pangborn-corp-mdd-1950.