United States Gypsum Company, and v. National Gypsum Company, And

387 F.2d 799
CourtCourt of Appeals for the Seventh Circuit
DecidedMarch 18, 1968
Docket15127_1
StatusPublished
Cited by11 cases

This text of 387 F.2d 799 (United States Gypsum Company, and v. National Gypsum Company, And) is published on Counsel Stack Legal Research, covering Court of Appeals for the Seventh Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
United States Gypsum Company, and v. National Gypsum Company, And, 387 F.2d 799 (7th Cir. 1968).

Opinion

FAIRCHILD, Circuit Judge.

United States Gypsum Company sued National Gypsum Company and Plaza Plastering Co. for infringement 1 of the Gill patent. 2 The district court found *800 the patent valid but not infringed. All parties appealed.

We conclude that the district court misconstrued the patent, that the patent was infringed if valid, and that the cause should go back to the district court to consider and determine certain issues as to validity, after supplementary trial if deemed necessary.

The patent contains five claims, the first to a combination and the other four to methods, the parties and the district court having usually treated claim 5 as representative of the method claims. All claims concern the art of producing smooth, seamless joints in walls made of wallboard.

Drywall construction is presently used in over 70 percent of residential construction. Large sheets of wallboard are nailed to studding to form interior walls. Where two sheets joint, the industry has for a long time used a cement or “mud” and strips of bridging material such as cloth, metal, or paper. Machines are widely used to apply the tape. Those machines generally apply the cement to the back of the tape just before the tape is placed along the joint. Later a top coat cement is applied to make the joint smooth and indistinguishable from the rest of the wall.

The several types of tape met with varying difficulties. Loosely woven cloth tape did not have sufficient transverse strength. Smooth metal tape did not form a solid bond with adhesives. Metal tape with holes allowed the cement to exude through the holes and harden into “keys” which helped to hold the tape tight, but required sanding. Paper tape with punched holes often caused the pattern of holes to show through the finishing coat, and when used in the taping machines caused difficulty because the adhesive came through the holes before the tape was on the wall. Perforation by punching often left burrs, and nodules of cement were likely to form on the surface of the tape away from the wall. Paper tape without perforation was also used some years ago, but apparently blisters will form unless there is some way for the air to escape.

The Gill patent is directed at a particular kind of tape, with minute perforations, to be used on wallboard joints, although four claims pertain only to a method of using it, and in claim 1, the tape itself is patented only as one element of a combination. The patent office had refused to patent the tape alone and the machine devised for producing it.

Claims 1 and 5 of the Gill patent are:

“1. The combination with wall-boards attached to a support and having edges in substantially abutting relationship forming a wallboard joint, of a strong thin cellulosic strip having perforations throughout with diameters from about 0.02 inch to 0.002 inch, said strip being adhesively secured over said joint and the edges of said wallboards adjacent thereto.
“5. The method of covering the joint between adjacent wallboards which comprises adhesively securing over said joint a strip of strong paper provided with substantially uniformly arranged spark-produced perforations having diameters from about 0.02 inch to 0.002 inch to permit the escape of air entrapped beneath said strip while substantially preventing the escape therethrough of adhesive employed to secure the strip in place.”

Infringement.

The district judge first addressed himself to the question of infringement. It is clear that National has produced and sold spark perforated paper tape for use on wallboard joints and that Plaza has so used it, all without license under the Gill patent. It also appears that National’s management knew of the patent and considered that there would be infringement if the patent were valid. The court, however, considered the National tape sufficiently different from the tape described in Gill so that its use did not infringe. The conclusion was based on an interpretation of Gill in three particulars which, with all respect, we consider erroneous.

*801 Claims 1, 2, and 5 state that the perforations in the tape have “diameters from about 0.02 inch to 0.002 inch * * * Claim 3 says “diameters from substantially 0.02 inch to substantially 0.002 inch”, and Claim 4 says “diameters of substantially 0.005 inch”.

Elsewhere, in the specifications, Gill explained: “The perforations, resulting from the high potential spark passing between pairs of electrodes are minute, averaging about .005 inch in diameter, generally within the range of from .002 inch to .02 inch in diameter. Many of the openings are somewhat elongated or oval, and the diameters specified are the average diameters arrived at by averaging the minimum and maximum dimensions of the openings.”

The perforations in a sample of National tape ranged in average diameter from a maximum of .0168 inch to a minimum of .0024 inch, all within the range indicated by Gill. The overall average was .0073 inch, larger than the .005 inch average indicated by Gill. This difference in the overall average was considered significant by the district judge. We disagree.

Claims 1, 3 and 4 refer to “perforations throughout”. Perforations in the sample of National tape, which was 2Via inches wide, did not occur, generally, within the outer half-inch (approximately) on either side. The district judge construed “throughout” in the claims as requiring the perforation to appear throughout the complete width of the tape. Claims 2 and 5 refer to “substantially uniformly arranged” perforations. The district judge noted a description of the National tape: “The perforations appear to be arranged roughly in six rows, although the pattern seemed almost random and was not too uniform,” and recalled his own observation “that it was arranged in rows as though it were fanned in a pattern.”

Statements by Gill in the specifications make it clear that the expression “throughout” did not mean that the perforations must be distributed close to and up to each edge of the tape. Using tape with the common width of 2%6 inches, the suggested distribution would leave a margin, without holes, of % inch along each edge. This is very close to the half inch margin in the National tape.

It is also said:

“The hole spacing and pattern in the tape are erratic. This results from the fact that the path of the sparks between pairs of electrodes varies considerably, due primarily to the lack of uniformity of the electrical resistance or conductivity on the tape itself.”

The material just quoted shows that the- phrase “substantially uniformly arranged” did not contemplate the symmetry and exactness of pattern which the district judge seems to have found essential.

Against the prior art background of punch perforated holes, the gist of the invention (if all tests of invention be met), was the use of tape with much smaller spark produced holes. The differences in average size of the perforations and in the exact pattern of distribution do not seem to us to warrant the significance accorded by the district judge.

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387 F.2d 799, Counsel Stack Legal Research, https://law.counselstack.com/opinion/united-states-gypsum-company-and-v-national-gypsum-company-and-ca7-1968.