8/8/2015 Allan Woodworth | UC Berkeley | Mechanical Engineering | IEOR 190G | Fall 2008 | Linde Air Products Co. v. Graver Tank & Manufacturing (1950)

Outline 8/8/2015 Allan Woodworth Players Welding Claims of Infringement Rulings and Appeals Overall Impact

Players 8/8/2015 Allan Woodworth Linde Air Products  Numerous products such as the USA’s first oxygen liquidation plant and hydrostatic forklift. Grover Tank Co.  Makes tanks (the kind that hold things such as air or oil) Lincoln Electric Co.  Makes flux

Welding 8/8/2015 Allan Woodworth What is welding?  A process that joins materials (usually metals) through coalescence.  Generally done by melting the workpieces and adding a filler material that cools to become a strong joint.

Metal Arc Welding 8/8/2015 Allan Woodworth

Flux 8/8/2015 Allan Woodworth Flux protects the weld from oxygen and other gases. As the electrode melts the flux disintegrates giving off protective vapors and creating a protective molten slag.

Patent 8/8/2015 Allan Woodworth Linde owned a patent for an electronic welding process ( ) 29 Claims

Dispute 8/8/2015 Allan Woodworth Linde sued Graver Co. and others for infringing the patent on their welding composition and process. Graver Co. said we’re not infringing because our flux uses manganese instead of magnesium. Magnesium Manganese

Dispute Continued 8/8/2015 Allan Woodworth The patent claims the use of an alkaline earth metal silicate which includes Magnesium Silicate but not Magnesium silicate.

District Court Ruling 8/8/2015 Allan Woodworth District Court found “that the Lincoln Electric Co. made, and the other petitioners used and sold, a flux substantially identical with that set forth in the valid composition claims of the patent in suit, and which could be made by a person skilled in the art merely by following its teachings. The petitioners introduced no evidence to show that their accused flux was derived either from the prior art, by independent experiment, or from any source other than the teachings of the patent in suit. The court found infringement of each of the four claims, and concluded that the respondent was entitled to a permanent injunction against future infringement and to an accounting for profits and damages…”

Appeals Court 8/8/2015 Allan Woodworth The case was sent to an appeals court which agreed with the decision made by the district court. The case was then sent to the 7 th district court which actually strengthened the infringement case claiming even more of the claims were infringed than originally ruled by the court. Finally, the case was sent to the Supreme Court and upheld claiming that though the “infringement was not literal” there was still infringement based on the “Doctrine of Equivalents.”

Doctrine of Equivalents 8/8/2015 Allan Woodworth It performs substantially the same function in substantially the same way to yield substantially the same result. then it is EQUIVALENT

Questions? 8/8/2015 Allan Woodworth