Anderson's-Black Rock, Inc. v. Pavement Salvage Co.
Headline: Patent on asphalt paving machine combining a radiant heater with standard paver invalidated as obvious, allowing competitors and road crews to use similar equipment without infringement.
Holding: The Court held that combining known paving elements and a radiant-heat burner into one machine was obvious and not patentable, so the patent covering the heater-equipped paver is invalid.
- Allows manufacturers and road crews to use radiant-heated pavers without this patent's restrictions.
- Clarifies that combining known parts for convenience is not a patentable invention.
- Reduces legal leverage for patent claims based on commercial success alone.
Summary
Background
A company (respondent) owned a patent assigned by an inventor for a machine meant to fix the “cold joint” problem in asphalt paving. The invention put a radiant-heat burner, a spreader, and a tamper/screed together on one paving machine chassis. The alleged infringer (petitioner) put a radiant heater on a standard paver. Earlier patents and machines already showed radiant heaters and standard pavers separately.
Reasoning
The Court asked whether putting these known parts together created a real invention. It found each piece was old in the field and the heater itself was already known. The heater works independently and would solve the problem even if used separately; combining it with the paver was mainly a convenience and did not produce a new function or a synergistic result. Expert doubts and commercial success did not make the combination inventive. Applying the legal test for obviousness, the Court concluded the combination was obvious to someone skilled in paving technology and therefore not patentable.
Real world impact
The Supreme Court reversed the intermediate court and held the patent invalid for obviousness under the patent statute. That means this particular patent cannot be used to block others from using the same heater-on-paver idea. The decision rests on the view that adding known parts together without a new function does not deserve a monopoly under the patent laws.
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