In the case of Jeffrey Manufacturing Company v. Blagg, 1914, the U.S Supreme Court dealt with a patent dispute. The plaintiff, Jeffrey Manufacturing Company claimed that Blagg had infringed on their patented mining machine design which was used for undercutting coal in mines. However, the defendant argued that he had not violated any patents as his machine was based on an older model and did not incorporate any new or unique features from Jeffrey's patented design. After considering both arguments and examining the machines in question, it was determined by lower courts that there were no significant differences between them to warrant a patent infringement claim. The Supreme Court upheld this decision upon appeal stating that while minor alterations may have been made to improve efficiency or durability of these machines over time; they did not constitute substantial changes worthy of new patents nor could they be considered as infringing upon existing ones if similar designs already existed prior to those improvements being made.

In the dissenting opinion for Jeffrey Manufacturing Company v. Blagg, it was argued that the majority's decision to uphold a patent infringement claim against the defendant was incorrect. The dissenting justices believed that there were significant differences between the plaintiff's patented design and the defendant's product, enough so as not to constitute an infringement of patent rights. They contended that these differences should have been taken into account by lower courts when making their decisions. Furthermore, they disagreed with how previous court rulings on similar cases had been interpreted in this case, arguing instead for a more nuanced understanding of what constitutes 'equivalent' designs under patent law. Ultimately, they felt that upholding such broad claims could potentially stifle innovation and competition within industries.