Del Zotto Products of Florida makes building forms and precast concrete products. Its Gold Rock blocks include a protruding lifting device on the top surface, and a recess on the bottom surface. It is possible to position the Gold Blocks, one on top of the other, using the lifting device and recess to align the blocks. Problem is, Stone Strong, LLC owns a number of patents directed generally to concrete blocks which have a lift loop on the top of the block which fits into a recess in the bottom of the block above to assist with aligning blocks. Stone Strong sued for patent infringement.
The key factor in resolving this determinative issue is the size of the recess or notch on the bottom of the blocks in relation to the size of the lift loop on the top of the blocks. Obviously, as the tolerance between the two features increases, the efficiency of the alignment function rapidly decreases to a point that it becomes nonexistent. Clearly, however, a notch or recess that is one foot wide at the bottom, decreasing to 9½ inches at the top, with a height of 5 inches receiving a steel loop 4 inches in diameter, provides a capability of being used as an aid in alignment, and the claims of the patents in suit (as previously quoted) were literally infringed when Del Zotto offered to sell its Gold Rock forms and blocks. See Bell Communications 10 Research, Inc. v. Vitalink Communications Corp., 55 F.3d 615, 622-23 (Fed. Cir. 1995) (“[A]n accused product that sometimes, but not always, embodies a claimed method nonetheless infringes.”); Paper Converting Mach. Co. v. Magna-Graphics Corp., 745 F.2d 11, 20 (Fed. Cir 1984) (“[I]mperfect practice of an invention does not avoid infringement.”); Roche Prods., Inc. v. Bolar Pharmaceutical Co., 733 F.2d 858, 861 (Fed. Cir. 1984) (“Section 271(a) prohibits, on its face, any and all uses of a patented invention.”).