To what liberality of construction these claims are entitled depends to a certain extent upon the character of the invention, and whether it is what is termed in ordinary parlance a “pioneer.” This word, although used somewhat loosely, is commonly understood to denote a patent covering a function never before-performed, a wholly novel device, or one of such novelty and importance as to mark a distinct step in the progress of the art, as distinguished from a mere improvement or perfection of what had gone before. Most conspicuous examples of such patents are: The one to Howe of the sewing machine; to Morse of the electrical telegraph; and to Bell of the telephone. The record in this case would indicate that the same honorable appellation might be safely bestowed upon the original air-brake of Westinghouse, and perhaps also upon his automatic brake.
Eibel Process Co. v. Minnesota & Ontario Paper Co., 261 U.S. 45, 43 S. Ct. 322, 67 L. Ed. 523 (1923).
The Patent Office treated the Dickinson invention as a primary or generic one. So did the Court of Appeals of the District of Columbia (25 App. D.C. 316), Judge Rose of the District Court of Maryland (Hildreth v. Lauer & Suter Co., 208 Fed. 1005), and the Circuit Court of Appeals of the Fourth Circuit (Lauter & Suter Co. v. Hildreth, 219 Fed. 753). In this view, after a consideration of the record, and for the reasons stated, we concur. The history of the art shows that Dickinson took the important but long delayed and therefore not obvious step from the pulling of candy by two hands guided by a human mind and will to the performance of the same function by machine. The ultimate effect of this step with the mechanical or patentable improvements of his device was to make candy pulling more sanitary, to reduce 35*35 its cost to one-tenth of what it had been before him, and to enlarge the field of the art. He was, therefore, a pioneer.
Hildreth v. Mastoras, 257 U.S. 27, 34-35 (1921)(emphasis added).