Mitros:Homework 3 (2/4/2011)

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Relevant Patents

Glencoe/Rolf patent 2739518 (Issued in 1956, however, the device was marketed in May 1951, before Graham's '798 patent was filed)

Graham '811

Graham '798

Argument for Obviousness

In analyzing patent '798, it has been determined that the patent is invalid in light of the content of the previous art (as will be shown by both the '811 Graham patent and the Glencoe device) as well as the ordinary level of skill in the art required to devise the item contained in patent '798 . Therefore, by section 103 the patent should be considered obvious as has been defined by the standards of the courts and should be found invalid.

In order to establish the nature of the previous art, both the Glencoe mechanism and patent '811 were taken into consideration. Patent '811 claims to contain "a plow structure wherein the pumping action of the ground working tools enhance the desirable features of the plow and...improved mounting [that] reduces or eliminates the breakage of the ground working devices since they yield automatically under action of the springs when they strike immovable objects such as rocks or other destructions." Patent '798 claims the same general function except with a "simple and efficient manner and without producing destructive strains on the plow frame or excessive wear on the mounting parts." When comparing the structures of the two items contained within the patents the two mechanisms are very similar in nature. Both achieve the same general motion that allows the shank to rise over solid objects in the ground. This is done by attaching the shank to a spring and hinge system rigidly attached to a plow. However, there are two noticeable differences between the two systems. In '811, the shank is sandwiched between the fixed upper plate of the hinge and the lower plate which rotates relative to the top plate on a revolute joint. When a force is applied on the end of the shank, the part of the shank that rests in between the hinge pushes down on the lower plate, compressing the spring and rod device. When the force is no longer applied, the stored potential energy of the spring pulls both the lower plate and the shank back to its initial position. The shank is in not rigidly attached to the lower hinge and sliding is prevented by the rod and spring system that passes through the hinge and shank. In the '798 patent the shank is attached beneath the lower plate of the hinge. This is done by using a stirrup towards the back of the plate and bolting the front end of the shank and plate together. This different mounting prevents the "excessive wear on mounting parts" mentioned earlier. In patent '811, when the shank and lower plate were forced to rotate down, the shank had to use the rear edge of the upper plate as a fulcrum point to engage and push the lower hinge down. Over time this would wear out the upper plate. By attaching the shank to the bottom of the lower plate, this engagement with the upper plate was eliminated and the subsequent wear that was caused by it. However, this is not something that would be outside the skills of an ordinary mechanic in the art. Both patents require that one of the hinge plates be rigidly attached to the plow in order for the system to allow the proper motion of the shank. This left one of two options for positioning the shank on the moving plate. Either positioning the shank above the moving plate, as was done first in '811, or finding a way to mount it to the bottom of the moving plate, as was later done in '798. A mechanic who was seeking to address the wear out problem would be faced with only one other possible configuration with which to mount the shank to the underside of the hinge. In this configuration the shank would have to pull the hinge down instead of pushing it down. This would require that the shank be rigidly attached to the hinge as was done in '798. Since there was only one of two possibilities for mounting the shank in the design, and the variations in construction required to either push the lower hinge in the one configuration, or pull the hinge in the other configuration are limited, it can be assumed that an ordinary mechanic skilled in the art would be capable of producing the item contained in '798.

In the Glencoe patent, it claims to contain an invention that "relates to shank holders...which must necessarily be able to rock or pivot at its forward end to permit the implement to yield when exceptionally heavy obstructions are met." Essentially, it claims to meet the same requirements as set forth in patents '811 and '798. In fact, much like patent '798 it claims to also "provide the maximum in freedom of pivotal movement... so that no undue strain is placed upon any part of the mounting or holder for the shank." Upon further examining the device, all the elements it contains are also found within patent '798. The only significant difference being that the shank is mounted on the top of the rotating plate. However, the shank is still held in place through the use of the same stirrup type device as well as rigidly connected to the lower plate by a bolt at the end of the shank. From the Glencoe patent it is obvious that the use of these two tools for mounting an object prone to flexing has been previously established in the art and available as public knowledge.

The claims of patent '798 depend primarily upon the location where the shank is mounted to the mechanism as well as the way in which it is rigidly connected. The previous existence of the Glencoe patent and patent '811 show that these methods were already within the scope of the previous art and within the level of skill of an ordinary mechanic. Therefore, patent '798 should be considered obvious in its nature and should be considered an invalid patent.

Argument for Nonobviousness

Upon investigating patent '798 in light of the claims made within the Glencoe patent and patent '811 it can be argued that the contents of patent '798 are nonobvious in the scope of the previous art. When it comes to nonobviousness, there are three general criteria to consider: 1) The scope and content of the prior art; 2) The difference between the prior art and the patent in question; 3) The level of ordinary skill in the art. It can be argued that in the case of '798 these criteria have been satisfied and the patent was nonobvious.

When comparing '798 to '811 and the Glencoe patent, an understanding of the scope and content of the prior art can be developed. Additionally, these patents provide an example of the differences in the prior compared to '798. Looking at '811 it was clear that before '811, there was a well defined need to find a way to allow plows to safely work in soils that contain rocks and other hard objects without causing irreparable damage to the plow. '811 was the attempt to provide a solution to that problem. However, the way it was designed, it was common for the top plate of the hinge to be worn down by the shank constantly pivoting on it. This particular part was difficult to replace. Therefore, patent '811 failed to fully satisfy long desired needs that the previous art desired to find a solution to. The design in '798 addresses these concerns and provided a more comprehensive and complete solution to the problem at hand. Even though '798's general function is similar to that of '811, its long term functioning provides a completely different outcome by preventing the inevitable and irreparable damage that was common with the '811 patenet

When addressing the issue of the level of skill required to develop '798, the conclusion is that the design would be outside the skill of the ordinary mechanic. If the mechanic were to start with the mechanism contained in '811 and told to address its problem of wear on the upper plate, going out of the way to mount the shank to the bottom plate would not be the obvious solution. Instead, it would seem plausible to address the location of contact and redesign it in a way that would prevent the wear. For example, one might decide to have the end of the upper plate curved so as to allow the shank to bend naturally along it. Or perhaps providing some sort of soft padding along the edge that could be easily replaced over time rather than having to replace the entire part. This point can be evidenced in the mechanism provided in the Glencoe patent. Even though the Glencoe patent contains most of the same parts as '798, it still mounts the shank above the lower plate. One could argue that its inventor, Mr. Rolf, had skills beyond that of an ordinary mechanic in the art as evidenced by him being awarded a patent for a mechanism in the same art. Yet even he continued to mount the shank on the top of the lower hinge plate. Therefore, it seems unlikely that an ordinary mechanic would have pursued the idea of mounting the shank to the bottom of the lower plate.

Therefore, by showing that '798 met the three general requirements of nonobviousness, the patent should be considered nonobvious and valid.