Vapor Blast Mfg. Co. v. Pangborn Corporation

186 F.2d 230, 88 U.S.P.Q. (BNA) 35, 1950 U.S. App. LEXIS 4167
CourtCourt of Appeals for the Fourth Circuit
DecidedDecember 30, 1950
Docket6175_1
StatusPublished
Cited by12 cases

This text of 186 F.2d 230 (Vapor Blast Mfg. Co. v. Pangborn Corporation) is published on Counsel Stack Legal Research, covering Court of Appeals for the Fourth Circuit 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 Corporation, 186 F.2d 230, 88 U.S.P.Q. (BNA) 35, 1950 U.S. App. LEXIS 4167 (4th Cir. 1950).

Opinion

DOBIE, Circuit Judge.

Plaintiffs, Vapor Blast Manufacturing Company (hereinafter called Vapor) and A. H. Eppler, instituted a civil action in the United States District Court of the District of Maryland, against the Pang-born Corporation (hereinafter called Pang-born), alleging infringement by Pangbom o'f the Eppler patent, No. 2,462,480. Only claims 15 and 21 of the patent are here in suit. The District Judge concluded:

“Summarizing our conclusions they are: (1) Defendant’s device infringes both of the claims of the Eppler patent in suit, numbers 15 and 21; (2) these claims are sufficiently specific in the light of the specifications ; but (3) they are invalid because anticipated by the prior British patent to Mathewson.” [93 F.Supp. 792, 798.] The complaint was, accordingly, dismissed and plaintiffs have duly appealed to us.

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 *232 liquid, and jetting portions of the circulating carrier liquid and abrasive against the -surface to be -cleaned or polished.”

“No. 21 (the apparatus claim) : Polishing apparatus comprising a charge of liquid carrier and abrasive particles in suspension therein in approximately fixed portions, 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 intermediate in communication with the nozzle and means for pumping the said charge through the system to supply the nozzle with portions of the charge under pressure.”

The details of the Eppler patent are made clearer by the rather elaborate specifications of the patent, from which we quote:

“A primary object of the invention i-s 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 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 it-s use permits of every type of operation from the coarsest rough or de-burring cut to the finest 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. % He jf; $

“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 fineness of the abrasive exceeds anything previously though usable in this art. As above pointed out, 80 mesh abrasive is the finest ordinarily used in sand bla-sting. 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 I 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 di-sclosed I may, for ordinary work, use 50 pounds of abrasive in a dry state to 50 pounds of the aqueous vehicle. To the *233 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. * * * * * *

“It is very desirable to use air rather than water as a means of imparting energy to the jet delivered from the nozzle. If water were added the character of the emulsion would constantly he changing. It is important to the control of the character of the finish and the amount of metal to be removed that the proportion of water to abrasive in the emulsion be kept relatively constant. Moreover, the fact that I employ chemicals in the emulsion makes it desirable to avoid undue dilution. Since the only water added to the emulsion is that which flushes the packing of the pump, I am able to operate over long periods with a -single charge of emulsion without materially changing the specified proportions of the ingredients. However, air would not be as satisfactory to impel the abrasive jet if the air had to do work in delivering the emulsion to the nozzle, as much of the force of the jet would then be lost. It will be noted that the circulation maintained by the pump is such that at all times a supply of emulsion is maintained in the overhead tank 37 at a constant pressure to flow by gravity to and from the nozzle whether or not the air valve is open. Thu-s, the only function of the air is to give force to the jet issuing from the nozzle.”

We first discuss the validity of the claims in suit. Claim 15, the process claim, and Claim 21, the apparatus claim, as the District Judge observed, “are obviously so interwoven that while the language of the two claims differs, it is appropriate to consider them together.” This becomes even more obvious upon a reading of the specifications.

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186 F.2d 230, 88 U.S.P.Q. (BNA) 35, 1950 U.S. App. LEXIS 4167, Counsel Stack Legal Research, https://law.counselstack.com/opinion/vapor-blast-mfg-co-v-pangborn-corporation-ca4-1950.