CARMAN INDUSTRIES, INC. v. WAHL

EDWARD S. SMITH, Circuit Judge.

This appeal is from the December 22, 1982, judgment of the United States District Court for the District of New Jersey holding U.S. patent No. 3,261,508 ('508) valid and infringed. Carman Industries, Inc. (Carman), appeals from that judgment. Carman commenced this action against Eugene A. Wahl and Vibra Screw, Inc. (Vibra), seeking a declaratory judgment that the '508 patent is invalid and not infringed. Vibra filed a counterclaim for patent infringement. The case was tried before the district court without a jury. After reviewing the record and briefs and, having heard oral argument, we find no clear error in the district court's findings of fact. The judgment is supported by the findings of fact. Thus, we affirm.

I.

On January 24, 1964, Eugene A. Wahl filed an application for patent for a "Vibratory Bin Activator" apparatus. U.S. patent No. 3,261,508 issued on that application on July 19, 1966.

A.

The invention relates to an apparatus that is attached to the base of a storage bin or hopper to promote the flow from the bin or hopper of solids that have poor flow characteristics.1 Prior art approaches to the problem of promoting the flow of difficult-to-handle solids involve the use of sweep arms, screw conveyors, or like elements. Claims 2, 3, 4, 6, and 7 are involved in this appeal and are set forth below:

The key point of contention with respect to the '508 patent is the compound concave surface limitations of claims 2 and 6, the only independent claims. The invention operates through a combination of three forces: the effects of the baffle member; the horizontal force supplied to the material particles through vibration of the material-receiving member; and gravity. The baffle forces the flow to proceed in an annular path down the concave surfaces of the material-receiving member. Through its vibration, the material-receiving member imparts horizontal motion to the flow, forcing the material into the void created below the baffle. In this manner the particles of material move down and in toward the center of the apparatus. The break in slope between the concave surfaces of the material-receiving member serves to "gather" the flow and accelerate the material through the central opening without competition between particles in the flow for position. Once the material passes this "break-slope," it proceeds rapidly to the lower concave surface. The break in slope between the concave surfaces serves to prevent the material from merely "crawling" down the side of the material-receiving member. Instead, the particles are presented with a sharp change in the forces being exerted on them, as indicated by the arrows in the following drawing:

B.

Judge Meanor, in a careful and comprehensive opinion, found that Carman failed to overcome the presumption of validity and he therefore held the patent valid. He found that the patent is not literally infringed but that the accused infringing device is the legal equivalent of the invention. He also found that, under the proposed construction of the claims under the doctrine of equivalents, the claims would be valid and, accordingly, held that the '508 patent is infringed by Carman's bin discharger.2 Relying on the Third Circuit's analysis of double patenting in Wahl v. Rexnord, Inc.3 the district court additionally found that the '508 patent was not invalid for double patenting. Carman appeals.

II.

Two principal issues are presented in this appeal:

In determining these issues we must accept the findings of fact of the district court unless we find them to be clearly erroneous.4

Carman argues that the "concave surfaces" limitation of claim 2 and the "concave member" limitations of claim 6 compel the conclusion that the '508 patent is not infringed by Carman's conical material-receiving member. If those limitations are interpreted to include a conical member, Carman contends that the claims would be obvious or anticipated and, therefore, the claims must be held invalid.5 With respect to double patenting, Carman urges the correctness of the trial court's earlier finding of invalidity in Wahl v. Rexnord, Inc.6

Vibra argues that it was error to conclude that the '508 patent was not literally infringed. Vibra contends that, in any event, the finding of infringement under the doctrine of equivalents should be affirmed. The '508 patent is valid in Vibra's view.

III.

With respect to the issue of validity, three grounds of invalidity are argued: (1) that the invention is anticipated under section 102; (2) that the invention would have been obvious under section 103; and (3) that the '508 patent is invalid for double patenting in view of the earlier issued design patent to Wahl allegedly covering the same subject matter.

A.

With respect to anticipation, Dumbaugh, U.S. patent No. 3,178,068 (Dumbaugh), is the closest prior art to the '508 patent.7 Dumbaugh was before the examiner during prosecution of the '508 patent. That reference discloses a conical material-receiving member having a continuous slope. Reference is made in Dumbaugh to Lee, U.S. patent No. 3,071,297 for the teaching of material-receiving member walls made up of a combination of curves having a varying, yet continuous, slope. Thus, the slope disclosed in Dumbaugh, while either uniform or variable, is nonetheless continuous. Dumbaugh also employs a baffle plate in the lower portion of the material-receiving member to regulate the flow rate and to maintain flow. Additionally, the reference includes an agitation apparatus for inducing spiral flow to the material.

The district court found several differences between Dumbaugh and the '508 patent claims. While Dumbaugh employs a baffle plate as does the '508 patent, it does not disclose a break in slope between two or more compound curved sections. Judge Meanor found that element to be a critical feature of the claimed invention. Lacking an element of the claims, the reference cannot anticipate them under section 102.

We conclude that the trial court's findings with respect to anticipation are not clearly erroneous. Dumbaugh does not disclose all of the elements of the invention and, therefore, the invention is not anticipated under 35 U.S.C. § 102.

B.

Several prior art references are cited by Carman as establishing that the invention would have been obvious within the meaning of 35 U.S.C. § 103. Dumbaugh and Lee, supra, are the most pertinent prior art references. Three additional prior art references were discussed by the court and are again propounded by Carman on appeal: Rouse, U.S. patent No. 3,012,697; British patent No. 508,528; and Wahl, U.S. patent No. 3,173,583.8 None of these three references was before the examiner. Nonetheless, the district court found that Carman had not overcome the presumption of validity.

In a careful analysis, the court below assessed the scope and content of the prior art, the differences between the prior art and the invention, and the level of ordinary skill in the art as required under Graham v. John Deere Co.9 The district court determined that while each of the references discloses some feature of the invention, there remain substantial differences between the prior art and the claimed invention. It found that none of the references teaches the break in slope between two or more curved surfaces. It determined that the differences were substantial. Additionally, Carman's evidence on the level of ordinary skill in the art was found to be inadequate.

Our review of the record reveals that the district court's findings are well documented. We find no clear error. None of the references teaches the compound slope feature of the invention. The findings of the trial judge clearly indicate that he did not feel that the conical-concave distinction was critical to the issue of obviousness and he therefore fully considered each of the references. He carefully evaluated all of the evidence relevant to the issue of obviousness and correctly ascertained the differences between the invention and the prior art. We agree fully with his conclusion that "the [prior art] does not inform persons skilled in the art that a compound slope arrangement as recited in the '508 claims could create horizontal flow characteristics * * * and thereby enhance the dischargeability of materials having poor flow characteristics." The invention would not have been obvious to one of ordinary skill in the art under section 103.

C.

The court below, applying the law of double patenting articulated by the Third Circuit in Wahl v. Rexnord, found no double patenting. Carman alleges that the precedent of this circuit on double patenting is not entirely consistent with Third Circuit precedent on this issue. The precedents of this court must control,10 but, contrary to Carman's contention, the test utilized by the Third Circuit, although not precisely in accord with our precedents, is not irreconcilable.

As a matter of legal theory, double patenting between a design and a utility patent presents significant problems. Judicial and scholarly criticism has been leveled at the concept of applying double patenting between a design and a utility patent.11 Design and utility patents are based on different statutory provisions12 and involve different subject matter.13 The scope of protection afforded by each type of patent is different. It has been asserted that these differences entirely obviate double patenting in the design-utility setting.14 However, there exists CCPA precedent to the effect that a double patenting rejection of a pending design or utility patent application can be sustained on the basis of a previously issued utility or design patent, respectively.15

The Third Circuit in Wahl reversed a summary judgment of invalidity which was based on double patenting, because of the existence of material issues of fact regarding the "identity" of the claimed design and utility inventions. In doing so, the court held that double patenting can exist between a design patent and a utility patent despite the differences in subject matter with which each type of patent is concerned. The test applied by the Third Circuit to determine whether double patenting exists is whether the two patents "cross-read," i.e., claim the same thing:16

In adopting the cross-reading standard, the Third Circuit in Wahl followed the decision in Ropat Corp. v. McGraw-Edison Co.,17 in which the Seventh Circuit sought to explain the CCPA holdings in In re Hargraves18 and In re Dubois:19

We agree with the above analysis that double patenting will be found in a design/utility situation if the two patents cross-read. Further, the precedent of this court supports a broader test of double patenting, encompassing the double patenting of obvious variations as well as of the same invention. However, rather than focusing on the point of novelty, we wish to clarify that double patenting is determined by analysis of the claims as a whole.20

Double patenting, as applied between a design and a utility patent, is a judicially created doctrine based purely on the public policy of preventing extension of the term of a patent, even where an express statutory basis for the doctrine is lacking. Double patenting may be found in a design/utility setting "irrespective of whether the patent relied on in the rejection and the application [or patent] on appeal involve the same invention, or whether they involve inventions which are obvious variations of one another."21 In the former situation ("same invention"-type) the test is whether the design and the utility patent claim the same subject matter. In the latter situation ("obviousness"-type), the test is whether the subject matter of the claims of the patent sought to be invalidated would have been obvious from the subject matter of the claims of the other patent, and vice versa. In considering that question, the disclosure of the "reference" patent may not be used as prior art. In certain situations, however, it may be used to define terms in a claim and to determine whether the embodiment claimed has been modified in an obvious manner.22

In applying the above tests, there is a heavy burden of proof on one seeking to show double patenting.23 Double patenting is rare in the context of utility versus design patents.24

We now turn to examine the facts relating to double patenting in terms of the above guidelines. The '068 (design) patent claims the visible external surface configuration of a storage bin flow promoter, as shown in the drawing below.

The claims of the '508 (utility) patent, on the other hand, are drawn to the interior construction of a flow promoter. The exterior appearance of the invention claimed in the '068 patent does not dictate the interior structure, nor does the exterior appearance disclose the function, of the invention claimed in the '508 patent. It is possible, and fully in accordance with the construction given the claims by the district court, to practice the invention claimed in the '508 patent without utilizing the claimed design. Moreover, the court found that Vibra had indeed practiced the invention claimed in the '508 patent without utilizing the design claimed in the '068 patent. Thus, the '508 patent does not claim the "same" invention as does the '068 patent.

The question then becomes whether one patent claims an obvious variation of that which the other patent claims, and vice versa. With respect to that question, Carman has failed to sustain the heavy burden referred to above. The record is wholly inadequate to establish that it would have been obvious to a person of ordinary skill in the art to make the interior of the device according to the claims of the '508 (utility) patent simply from knowledge of the exterior configuration of the device claimed in the '068 (design) patent. Thus, even if it would have been obvious to make the invention claimed in the design patent in view of the subject matter claimed in the utility patent by simply designing the exterior and interior walls of the material-receiving member to be parallel, as Carman has attempted to prove, that alone is insufficient to establish double patenting in accordance with the two-way test set forth above.

We hold that, under the above guidelines, the '508 patent does not claim the same invention as, or an obvious variation of, the invention claimed in the '068 patent. Thus, the design patent did not, in effect, extend the beginning of the term of the utility patent. For the above reasons, the '508 patent is not invalid for double patenting. We turn now to the issue of infringement.

IV.

The district court found that the '508 patent was not literally infringed but was infringed under the doctrine of equivalents. Vibra challenges the former finding and Carman the latter. Infringement is ultimately an issue of fact25 and, again, the trial judge's findings are not to be upset unless clearly erroneous.

A.

The finding that the claims are not literally infringed is based on the court's construction of the claims and, in particular, of the limitation "concave." The court received conflicting expert testimony on the meaning of the term "concave," as well as on the construction of claims. Additionally, the court noted various statements in the specification and claims of the '508 patent. These statements distinguish a concave form from a conical form. On the basis of this evidence, Judge Meanor concluded that the literal language of the claims was limited to a material-receiving member having compound concave sloped surfaces, to the exclusion of a conical shape.

We note that while opinion may vary with respect to the meaning of the term "concave," Judge Meanor correctly interpreted the literal language of the claims in light of the specification. In doing so he fully considered the conflicting expert testimony. He found that the distinction between conical and concave is disclosed in the specification and appears explicitly in claim 6. On the basis of these conclusions and findings we hold that the finding, that Carman's conical material-receiving member does not literally infringe the claims of the '508 patent, is not clearly erroneous. The district court's finding with respect to literal infringement is fully supported on the record.

B.

The claims were, however, held to be infringed under the doctrine of equivalents. The court first examined the invention and the alleged infringing device to ascertain if the circumstances were proper for application of the doctrine of equivalents26 — whether the accused device "`performs substantially the same function in substantially the same way to obtain the same result.'" These circumstances are met when the alleged infringer seeks to appropriate the invention with minor modification to avoid the literal language of the claims.27

The principal function of the invention is to promote the flow of material from the hopper. The accused infringing device also performs that function. While the accused infringing device does not perform the secondary function of stopping the flow when vibration is stopped, it was entirely proper for the court to conclude that the identity of primary function constitutes substantial identity of function for purposes of the doctrine of equivalents. There is no limitation in any of the claims in issue that would require the flow stopping function. It is apparent from the court's findings that both devices operate by inducing a similar pattern of flow through the material-receiving member. This flow is effected in both devices by the same combination of forces. The court found that the precise slope of the walls is not critical to the invention. The lateral force exerted on the flow is not substantially altered by the shape of the walls. Additionally, the same result is obtained from the invention and from the accused infringing device. We find no clear error with the finding that the accused infringing device is the legal equivalent of the invention. Therefore, we hold that application of the doctrine of equivalents was proper.

Once it is determined that the doctrine of equivalents is applicable, a finding of infringement is not certain. The doctrine of equivalents is subject to two types of limitation which may prevent a finding of infringement: (1) estoppel based on the prosecution history of the patent ("file wrapper estoppel") and (2) invalidity of the claims according to the proposed construction in view of the prior art. Estoppel, an affirmative defense,28 was not raised below. Carman strenuously argues the second limitation, however.

The court below, in an exhaustive analysis, examined the proposed construction of the claims under the doctrine of equivalents to determine whether such construction would invalidate the claims under section 102 or 103. Its analysis is more than adequate to answer this question.

Under the doctrine of equivalents, the court considered compound straight sloped (conical) walls to be the legal equivalent of compound varying sloped (concave) walls in the material-receiving member. Even with this expansion in the scope of the claims, Judge Meanor found patentable differences between the invention and the prior art. None of the references was found to disclose compound broken-sloped walls. We agree with the district court that, in spite of the broadening effect of the doctrine of equivalents, with such construction accorded the claims they would not be invalid in view of the prior art. Thus, application of the doctrine of equivalents is not limited in this case. We find no clear error in Judge Meanor's finding that the Carman device infringes the '508 patent under the doctrine of equivalents.

V.

The '508 patent was found valid under the applicable statutory and judicial criteria of validity in view of appropriate findings of fact. We agree with the district court that the '508 patent is not invalid under section 102 or 103. Additionally, the patent is not invalid for double patenting under the criteria articulated in this court's precedent. Thus, we affirm the district court's conclusion that, insofar as it is challenged here, the '508 patent is valid. We find no clear error in the findings below that the patent is infringed by Carman's device under the doctrine of equivalents, but not literally infringed. Thus, we affirm the judgment of the district court.

AFFIRMED.

NIES, Circuit Judge, concurring-in-part.

I concur in the decision that the '508 patent is not invalid for double patenting. However, I do not share the doubts that principles of double patenting should apply to design/utility patent situations. I also do not share the view that the Third Circuit standard which limited double patenting to "same invention" type is reconcilable with the decisions of the U.S. Court of Customs and Patent Appeals, e.g. In re Thorington, 418 F.2d 528, 537, 57 CCPA 759, 768, 163 USPQ 644, 650 (1969).

More significantly, I do not agree that in obviousness type double patenting each patent must be found obvious from the other. If one patent is obvious from the other and has the effect of extending its term, the second to issue is invalid. In this case I agree with the majority that it would not have been obvious to one of ordinary skill in the art with knowledge of the '068 design patent to make the claims of the '508 patent. Thus, the patentee has not obtained extended protection for the device claimed. Alternatively, since a device covered by the claims of the '508 patent need not take the shape claimed in the design patent, the term of the design patent is not being improperly extended by the utility patent.

Since I discern no possible extension of the term of protection of the invention of either patent, I agree that the '508 patent is not invalid for double patenting.