Hotchkiss v. Greenwood (Robins)
US Supreme court 1850
Evidence: Patent granted 29th July 1841.
Patent was for a new type of door/cabinet knob made out of clay and porcelin.
Suit brought against the defendants for alleged infringment in Circuit Court of the US for Ohio.
Defendants allege plantiffs were not the original or first inventors.
Justice Nelson gave the opinion
The earlier trial, the plantiffs had asked the judge to instruct the jury that although the clay knob, spindle and shank had already been known, the process of combining them was unique and new and therefore the patent was valid.
The court refused to give the instruction, and instead said that if the knobs and spindle and shank were of the same form as before, and if the method of attaching them by dovetail to each other, and no more ingenuity or skill was required other than that possessed by an ordinary mecahnic, then the patent was invalid.
The plantiffs wanted it declared a mistrial based on this.
The new porcelin and clay knob prevented the shank from immediately acting upon the knob, which made the porcelin knob stronger and therfore was a new invention. The use of different materials is not patentable, but an improvement is.
However, this was concluded to not require ingenuity, it could be done by a skilled mechanic and the imporvemnt in sturdiness could have been accomplished using many materials, not only those patented.