And if more is required to make our point, there is the venerable case of Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1851), cited approvingly in KSR Int’l Co. v. Teleflex Inc., supra, 550 U.S. at 406, 415, which denied patentability to an invention consisting of the substitution of a clay or porcelain knob for a metallic or wood knob in a doorknob (the doorknob itself, as distinct from the knob on the end of it, being an assemblage of knob, shank, and spindle). Other substitution cases in which patentability was denied on grounds of obviousness include Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 1535–38 (Fed. Cir. 1983); Brunswick Corp. v. Champion Spark Plug Co., 689 F.2d 740, 749-50 (7th Cir. 1982), and Lyle/Carlstrom Associates, Inc. v. Manhattan Store Interiors, Inc., 635 F. Supp. 1371, 1381-83 (E.D.N.Y. 1986), aff’d, 824 F.2d 977 (Fed. Cir. 1987). These decisions, too, support our conclusion that the judgment must be reversed with instructions to dismiss the suit.