Vas-Cath Inc. v. Mahurkar
935 F.2d 1555 (1991)
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Rule of Law:
Drawings in an earlier-filed design patent application can satisfy the written description requirement of 35 U.S.C. § 112, first paragraph, for a later-filed utility patent application, provided the drawings reasonably convey to a person of ordinary skill in the art that the inventor was in possession of the claimed invention at the time the design application was filed.
Facts:
- Sakharam Mahurkar invented a double lumen catheter with joined semi-circular tubes and a single tapered tip, which was an improvement over prior art coaxial catheters.
- On March 8, 1982, Mahurkar filed a U.S. design patent application ('081 design application) that consisted of drawings of his catheter.
- After filing the U.S. design application, Mahurkar filed a Canadian Industrial Design application with the same drawings and additional text, which issued as Canadian patent '089 on August 9, 1982.
- On October 1, 1984, more than a year after the Canadian patent issued, Mahurkar filed a U.S. utility patent application ('601 utility application) for the catheter, which included the same drawings as the '081 design application.
- This '601 utility application, and a subsequent continuation application ('592), claimed the benefit of the March 8, 1982 filing date of the '081 design application.
- The U.S. Patent and Trademark Office issued two utility patents, the '329 and '141 patents, based on these applications.
- Vas-Cath Incorporated began manufacturing catheters similar to Mahurkar's patented design.
Procedural Posture:
- Vas-Cath sued Mahurkar in the U.S. District Court for the Northern District of Illinois, seeking a declaratory judgment that its products did not infringe Mahurkar's '329 and '141 patents.
- Vas-Cath's complaint alleged the patents were invalid under 35 U.S.C. § 102(b) because they were anticipated by Mahurkar's own Canadian '089 patent, which was published more than one year before the utility patents' 1984 filing date.
- Mahurkar counterclaimed for patent infringement.
- Both parties filed motions for summary judgment on the issue of patent validity.
- The district court granted partial summary judgment in favor of Vas-Cath, holding that the utility patents were not entitled to the 1982 filing date of the '081 design application because its drawings failed to meet the 'written description' requirement of § 112.
- The district court consequently declared both of Mahurkar's patents invalid as anticipated by the Canadian patent.
- Mahurkar (appellant) appealed the district court's judgment to the U.S. Court of Appeals for the Federal Circuit, with Vas-Cath as the appellee.
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Issue:
Do drawings alone in a design patent application satisfy the written description requirement of 35 U.S.C. § 112, first paragraph, to support the claims of a later-filed utility patent application and entitle it to the earlier filing date under 35 U.S.C. § 120?
Opinions:
Majority - Rich, Circuit Judge.
Yes, under proper circumstances, drawings alone may provide a sufficient written description of an invention as required by § 112. The test for sufficiency is whether the disclosure reasonably conveys to an artisan of ordinary skill that the inventor had possession of the later-claimed subject matter at the time the earlier application was filed. The court found that the written description requirement of 35 U.S.C. § 112 is separate and distinct from the enablement requirement. The district court erred by requiring the drawings to describe 'what is novel or important' and to 'necessarily exclude' all other variations outside the claimed range. The invention is defined by the claims, and the record showed Mahurkar patented exactly what his '081 design application drawings depicted. Furthermore, Mahurkar's expert declaration created a genuine issue of material fact as to what a person of ordinary skill in the art would have understood from the drawings regarding the claimed dimensional ranges, which Vas-Cath failed to rebut. Therefore, summary judgment was inappropriate.
Analysis:
This decision clarifies the important distinction between the written description and enablement requirements of § 112, reaffirming that they are separate legal standards. It establishes significant precedent by confirming that drawings from a design patent application can satisfy the written description requirement for a subsequent utility patent, allowing the utility patent to claim the design's earlier filing date. This holding strengthens an inventor's ability to rely on early design filings for priority and makes it more difficult for challengers to invalidate patents on summary judgment based on a lack of written description, as the inquiry is a fact-specific question viewed from the perspective of one skilled in the art.
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