In the 1894 case of Keeler v. Standard Folding Bed Company, the U.S Supreme Court ruled on a patent dispute between two companies over folding bed designs. The plaintiff, Keeler, claimed that Standard Folding Bed Company had infringed upon his patented design for a folding bed. However, the court found that while there were similarities in both designs' functionality and purpose (i.e., to save space), they differed significantly in their mechanical construction and operation methods - enough so to not constitute infringement under patent law. The court held that an invention must be new and useful but also non-obvious to someone skilled in its particular field or industry. In this case, it was determined that any skilled mechanic could have made similar modifications as those seen in Keeler's design without infringing upon his patent rights. This ruling established important precedents regarding what constitutes 'obviousness' within patent law – namely that minor alterations or improvements on existing inventions do not necessarily warrant new patents if these changes would be obvious to anyone with expertise in the relevant field.

In the dissenting opinion for Keeler v. Standard Folding Bed Company, it was argued that the patent in question should not be invalidated due to lack of novelty or non-obviousness. The justice disagreed with the majority's interpretation of what constitutes an 'invention,' arguing that even small improvements on existing designs can and should be considered inventions if they provide new and useful results. He contended that while the design may seem simple or obvious after its creation, this does not mean it would have been so before its existence. Furthermore, he pointed out inconsistencies in how similar cases had been handled by courts previously, suggesting a need for clearer guidelines regarding patents' validity criteria.