Doctrine of Equivalents Case List
Add your case to the list with a one-paragraph (approximately 250 words) summary of the facts at issues, i.e., "an umbrella is or is not equivalent to a parasol because..."
Please put the cases in chronological order. If two are from the same year, then put them in alphabetical order. Also put your name, your login name or NDID number with your case. Use the following for a template.
- Goodwine v. Batill, 123 US 4567 (1066)
This case concerned a patent for an iPad and the patentee sued the maker of an iPod for infringement. The important part of the claim was "a device for playing music and other media comprising a touch screen..." The court held that iPod infringed the iPad patent because the ... was equivalent to the ... because ...
- AMEC Liquidating Trust v. IVAC Corporation, 885 F.2d 1574 (1989)
AMEC had a patent for a thermometer with a plastic cover held on by a hooking type mechanism. IVAC created a thermometer with a cover held on by a ring that created a friction lock. The CAFC held the IVAC invention was non-infringing on the AMEC patent because under the doctrine of equivalents, it did not perform the same function in the same way. The AMEC thermometer cover used an inscription fit, which created deep scratches in the cover. The IVAC thermometer used a friction fit, which only created superficial scratches in the cover. The CAFC found that the superficial scratches did not constitute an inscription fit. Also, the CAFC decided that AMEC did not present any evidence proving that the ring in the IVAC patent was equivalent to the “hook” in the AMEC patent. Because of this, the patent was non-infringing under the doctrine of equivalents.
- Johnston v. IVAC Corp., 885 F.2d 1574 (1989)
The inventor, Turner, invented a thermometer probe cover that stays on (this was owned by AMEC). It kept the cover on via a sharp metal hook to tear into the cover’s plastic. IVAC developed a thermometer that served a similar purpose of keeping the probe cover on, except that it did so with a ring on the probe (to hold the cover via friction). IVAC intentionally left the probe free of any sharp edge to ease the removal of the probe cover when needed. District Court of Southern California ruled in summary judgment that IVAC’s thermometer probe covers do not infringe AMEC’s. On appeal from AMEC, the Court of Appeals affirmed the judgment. A ring that does not tear the plastic cover is not equivalent to the hook that does. 
- Lemelson v. General Mills, Inc., 968 F.2d 1202 (1992)
Lemelson sued Mattel, alleging that Mattel's "Hot Wheels" toy car track infringed on his patented toy track. The U.S. District Court for the Northern District of Illinois found in favor of the plaintiff. Mattel appealed to the CAFC. The Court held that the "Hot Wheels" track did not contain all the limitations of the patent; it was equivalent to the prior art. That is, Lemelson's patent could not be both valid in light of the prior art and infringed upon by Mattel. Furthermore, upon his first application, claim 3 of Lemelson's patent had five clauses. The PTO examiner found the patent to be indistinguishable from the prior art. Lemelson added clauses [f] and [g] and received a patent. The important parts of the claim were, "[f] said guide means include a pair of spaced apart runner portions for defining the pathway of a vehicle moving over said track, [g] said spaced apart runner portions include upwardly extending rails for guiding the wheels of a vehicle." The Court held that "Hot wheels" did not contain any elements equivalent to the clauses [f] and [g]. The Court also noted that the public is entitled to the PTO record to determine the scope and meaning of claims.
- Valmont Industries Inc. v. Reinke Manufacturing Company Inc., 983 F.2d 1039 (1993)
This case concerns an adaption for center-pivot (i.e. rotating) irrigation systems. The adaption (an apparatus that attaches to the main frame of the sprinkler) allows the corners of a field, normally missed by the standard rotating irrigation system, to be watered. The infringement issue relates to the means by which the position of the sprinkler is detected, relative to the field. The patent uses a method of pivot angle encoders, while the "infringing" patent uses buried electromagnetic cables to guide the sprinkler around the field.
The CAFC ruled that the second device was not infringing, reversing the decision of the district court. The district court argued that the means of controlling the system were equivalent. The CAFC's argument was that while the two irrigation systems performed substantially the same overall function to obtain substantially the same overall result as the claimed invention, the way those results were achieved was substantially different. "Comparison of these two control means compels the conclusion that the claimed control means and Reinke's control means are not structurally equivalent.[...][E]ven though both the control means in the specification and the control means on Reinke's device use electric signals, the structures generating those signals are strikingly different."
Because the doctrine of equivalence requires that the two devices perform substantially the same function in substantially the same way to achieve substantially the same results, the two control systems were not equivalent under the doctrine of equivalence because they did not meet the "way" requirement of the doctrine of equivalence.
- William Bradshaw and Robert Shepherd v. Igloo Products Corp. 1997 WL 543109 (US District Court, N.D.Ill.)
William Bradshaw sued Igloo Products for infringement of a wheeled cooler. Bradshaw’s patent was for a cooler with a pulling handle and two lifting handles, one of which was connected on the same axle as the pulling handle. The Igloo products in question were the Rolling Kool Locker which had a rotatable lifting hand that can also be used to pull the cooler and the Cool Roller which had separate lifting and pulling handles coupled to separate axles. The court decided that the prior art for the Cool Roller was a different patent, the Mason patent. This patent was for a wheeled cooler with separate lifting and pulling handles. The Mason patent was granted before Bradshaw’s patent. The court ruled that the Cool Roller fell under the Mason patent. Therefore, if Bradshaw’s patent were to be expanded to include the Cool Roller’s handles, it would be an invalid patent as a result of the prior art, the Mason patent. This leads to a method of deciding infringement. If the product in question mimics prior art, then it cannot infringe the patent otherwise that patent would be invalid. In deciding infringement for the Rolling Kool Locker, the court decided that it was up to a jury to decide whether the Kool Lockers handles were equivalent to Bradshaw’s patent, since there was no other glaring evidence.
- Hale Propeller, L.L.C. v Ryan Marine Products Pty., LTD., et al, 151 F. Supp .2d 183 (2001) Connecticut District Court
Ryan owned patent 4411073, issued on 25 October 1983, which concerned devices to measure the pitch of propeller blades. Ryan originally filed the claim on 13 July 1981 it was rejected and then ammended on 4 October 1982. Hale's device called the "Hale Propeller MRI" was developed in 1997. In question are claims 1(b),(c),(f), and 6. A third party, Michigan Wheel Corporation, a distributor of Hale's invention filed for patent invalidity. The important differences between Hale's and Ryan's device are that Hale's does not use gears or worm-drives to rotate the blade and the device does not give direct readouts of the measurements using electric circuits. The issue with claim 1(b) was if a roller was a necessary part of the structure because it prevents skipping of the probe making the measurements more accurate. The court used means-plus-function to rule that the roller was important and Hale did not infringe. The issue with claim 1(c) deals with whether a worm or gear drive is necessary to rotate the blade. Ryan's patent discloses a hand-cranked device, like Hales, but includes a worm-drive. Part of Ryan's ammendment to his claim was to include worm gear to the hand-cranking device and therefore the court used prosecution history estoppel to make their decision because Ryan forfeited that claim (hand-cranked device without worm-drive) in order to get the patent and therefore cannot use doctrine of equivalents to get the claim back. The issue of claim 1(f) was whether the computer in the claim was a special computer needed for the readouts. The court ruled that the claim was not that narrow, but then the court ruled that claim 6 dealt with a computer that receives measurement data from the optical encoder and therefore Hale did not infringe. The patent was also ruled valid using the roller and worm drive to prove that it was non-obvious §103, definitively disclosed §112, and not anticipated by prior art §102(b).
- Siemens Medical Solutions USA, Inc. v. Saint-Gobain Ceramics & Plastics, Inc. Nos. 2010-1145, 2010-117. (2001) United States Court of Appeals, Federal Circuit
This case began as an infringement lawsuit by Siemens Medical Solutions USA, inc. against Saint-Gobain Ceramics and Plastics, Inc. for the alleged infringement of a patent held by Siemens for a scintillator, a part of an x-ray machine that detects radiation. Saint-Gobain owned a patent for a similar device and the circuit court found that this patent infringed on the patent held by Siemens, which was filed earlier. Though the doctrine of equivalents was used to rule infringement, Saint-Gobain was found to have accidentally, rather than willfully infringed and Siemens was awarded 52.3 million dollars.
Siemens filed for patent number 4,958,080 on August 4, 1989. This patent was for a scintillator containing cerium-doped- lutetium oxyorthosilicate. This is a component of a radiation detector that absorbs gamma-ray photons from an x-ray machine and converts them to visible light so the results can be interpreted. Saint-Gobain also produces scintillators, filing patent number 6,6424,420 in 2000 for a cerium-doped lutetium-yttrium orthosilicate. The chemical composition differs from that of the Siemens' patent as %10 of the lutetium is substituted for yttrium. These scintillators were sold by Saint-Gobain to Philips Medical Systems, a competitor of Siemens. The circuit court found that the composition of Saint-Gobain's scintillator preformed largely the same function in the same manner as Siemens' patent, and therefore was infringement under the doctrine of equivalence.
Saint-Gobain filed a motion for a new trail, on the basis that the jury was not told that infringement by the doctrine of equivalence must be proved by clear evidence and argued that damages should be remitted. The Federal Appeals Court did not grant Saint-Gobain a new trial, but did reduces the damages to 44 million.
- Sunbeam Products, Inc. v. Homedics, Inc., Slip Copy, 2010 WL 5230892 (2010)
This case involved a patent for a force-transmitting bearing used with a platform scale. Sunbeam held a patent which specified bearings which were attached to the platform via loose tabs which allowed the bearings to move horizontally. The patent claims required the base of the bearing to be oriented parallel to the platform and remain parallel to the platform at all times. The structure of the accused device was such that the bearings were connection to the platforms using dimples on the lower surface of the platform which the bearings fit into. Sunbeam had criticized prior art which used a similar dimple connection during prosecution beacuse of the potential for unwanted force moments applied by the bearing. The CAFC upheld the District Court's finding of no infringement based on the doctrine of equivalents because bearings which rocked and pivoted, as the accused device did, did not fall within the reach of the patent claims because they did not remain parallel to the platform at all times.
- Kustom Signals, Inc. v. Applied Concepts, Inc., 264 F.3d 1326 (2001)
Kustom Signals held a patent for a multimode traffic radar system which will show either the fastest speed or the strongest signal. Three of the claims used the word "or" in their wording. Kustom claimed that the "or" was a logical operator meaning one, the other, or both. Applied Concepts had designed a radar system which returned both the fastest speed and the strongest signal. The Court held that the word "or" was to hold its traditional, customary meaning as being exclusive, not inclusive, of the two statements.
901 41 7852