Homework 3 - Nonobviousness Analysis - Graham Patent
Patent in Question: Clamp for Vibrating Shank Plows (2,627,798; Graham, 1953)
This patent claims a mounting device for a rocking plow that consists of a fixed part and a moving part. The lower face of the moving part is attached to the upper face of the plow shank; and the combination of the moving part and plow shank pivots about the stationary part, allowing for the rocking motion of the plow. The moving part and stationary part are connected in the rear by a horizontal dowel, allowing for a pivoting motion, and the moving part and the plow shank are clamped in the front by a nut and bolt. The plow shank, moving part, and stationary part are all connected in the front by a vertical dowel with a spring, so that they are normally all held together (lowering the plow into the ground) but the plow can be lifted by encountering a rock, etc. which extends the spring until the spring has enough force to pull it back. An I-beam member runs across the multiple arms of the blow to act as a stabilizing member and is clamped on top and bottom by hooked arms which are attacked to a vertical rod.
Referenced Patent: Vibrating Plow and Mounting Therefore (2,493,811; Graham, 1950)
This patent is for a plow and corresponding mounting configuration that produces a rocking movement that is desirable when plowing a field. The plow shanks are attached to a pivot that consists of a moving part and a stationary part. The moving part pivots about the rear end of the stationary part and the configuration is fastened in the front by a dowel with a spring, that produces the rocking motion. The upper face of the moving arm is mated with the lower face of the plow shank, attaching the plow shank bewteen the two arms of the mounting device. An I-beam member runs the span of the plow to act as a stabilizing member, and its lower flange is fastened to each plow arm by hooked clamps.
Referenced Patent: Fastening Device (2,014,451; Pfeifer, 1935)
This patent details a fastening system intended to provide a secure seal when attaching corrugated sheet metal to other construction elements. The relevant part of the patent is a hooked clamp used to attach the bottom flange of a C-shaped member to some other construction element. The clamp is shaped to mate with the lower face of the bottom flange and then hook up to also mate with the upper face of the bottom flange. This provides a secure fit and stable mounting configuration. The clamp could obviously be altered to fit different beam shapes.
Argument for the Validity of the Patent (Nonobvious)
It can be argued that the patent is nonobvious and thus valid because it is an improvement on the prior art. Other similar plows and mounting configurations have been produced, such as patent '811, but the patent in question ('798) provides a more stable configuration by clamping the I-beam support both on the bottom flange and the top flange with hooked arms, fastened to the fixed part of the clamp by a bolt. According to the Patent Clause of the Constitution, the invention is both novel and useful - the latter evidenced by its wide commercial success.
The clamp in question is similar to the clamp of a previously patented plow and mounting device ('811) but improves upon the stability of the clamp and the I-beam stabilizer. It also appears that the new clamp allows for a greater range of pivotal motion of the plow shank by mounting the shank on the underside of the pivot arm instead of between the pivot arm and the fixed part. This inversion would allow the plow shank to pivot further before its rear end made contact with the fixed part of the clamp, in turn allowing the plow to accomodate larger rocks and obstructions without damage.
Argument for the Invalidity of the Patent (Obvious)
The patent in question would not be valid under the Patent Act of 1952, specifically under the US Code, Title 35 Section 103. This states that the level of invention and novelty of a patentable item must be beyond the ability of a person with ordinary skill in the art. In this case, a person of ordinary skill could be assumed to be anyone with experience in the plow industry, or a mechanical engineer.
The patent '798 does not differentiate itself enough from the patent '811 to be considered nonobvious. The only appreciable changes include a more stable mounting configuration of the I-beam crossbar and mounting the plow shank below the pivot arm instead of above it. While these may yield improved results and an overall better project, anyone with a basic knowledge of mechanics, including a senior aerospace engineering major, would be able to realize that clamping the I-beam on top as well as on bottom would provide much more stability, and that mounting the shank below the pivot arm would increase the range of motion of the plow.
Additionally, the devices used to clamp the I-beam resemble the hooked clamps detailed in a patent by Pfeifer ('451) for use in fastening corrugated metal. While this patent was designed for an entirely different purpose, it is explicitly patented for any use. The hooked member was designed to clamp the bottom flange of a half-I-beam structure, and it would be obvious to anyone that this would be a useful way to clamp any I-beam flange.
The patent '798 may demonstrate a notable improvement on the prior art, but the only novel thing about the invention is how it combines a number of older inventions. And this combination is in no way surprising or beyond the understanding of anyone familiar with basic mechanics. Therefore, under Section 103, this patent must be found obvious and thus invalid.