BWC --- HW 1.28

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Homework 1.28 There are two references cited that pertain to the homework at hand. I will first discuss the relevant items in each document, and then apply the analysis of Hotchkiss and A&P to the patent that I’ve chosen and determine the patentability of my patent with all things considered. Patent #2576981, herein referred to as Vogt, was filed in December 1951 by R. Vogt. In short, it is a winglet that is twisted like a propeller to gain a thrust advantage. At this time, it was well known to aerodynamicists that an end plate on a wing reduces the lift induced drag on a wing. However, such an end plate also results in an increase in total drag, as the resulting skin friction is greater than any improvement otherwise. A greatly contributing factor to this topic was a report filed in 1950 by NACA regarding various plates on the ends of wings. In short, engineers were researching ways to garner the benefits of reducing the lift-induced drag without paying an even greater penalty in the skin friction realm. Vogt’s solution was to design a propeller-like winglet that would account for the extra skin friction drag by producing a thrust vector, which when combined with the reduced lift-induced drag, would be of greater magnitude than the resulting increase in skin friction drag. Specifically “It is a primary object of this invention to provide wing tip fin means capable of converting part of the energy in the top vortices of an airplane wing into useful thrust” – Vogt Throughout Vogt, it becomes even more clear that this is the main object of his invention. While other consequences are noted, such as a beneficial reduction in wing bending moments at the root, they are not the primary aspect of this invention. There is little to no ( < 5 deg ) leading edge sweep present. Patent #4245804, filed in January 1981 by Ishimitsu, also addresses the issue of optimizing a winglet structure. The main focus of this patent is to find a suitable winglet solution for high-speed aircraft. Nonetheless, there are still some applicable aspects of this document that should be considered when considering my patent. First, the winglet only extends upwards, and is a continuation of the wing rather than an attachment. This is done to prevent any unwanted shock waves from forming at the connection between the wing and the winglet. Second, the wing and winglet do not meet at a perpendicular angle, but rather stop short of it. Finally, there is a significant leading edge sweet ( 55-75 deg) present to benefit from a certain type of vortex flow. Ishimitsu states “In this respect, it has been discovered that utilizing such a sweep angle generates a vortical flow pattern along the base of the tip fin which maintains boundary layer attachment during high speed flight to thereby prevent drag penalties that could at least offset the gains in aerodynamic efficiency effected by the invention” – Ishimitsu While Ishimitsu does not directly address a wing operating at high coefficients of lift, the same principle would apply. With the patent that I have chosen to analyze, Jupp and Rees try to address the problem of an effective winglet in high lift situations. They recognize that the winglet will not perform adequately in a high lift situation without some additional precautions being taken to account for separating flow. Vogt did not address this topic, but Ishimitsu did. Jupp and Rees use a high leading edge sweep winglet that extends both above and below the wing to provide the benefits of a winglet while not paying an excessive drag penalty. Now I will apply the opinions from Hotchkiss to my patent in light of the previous discussion. Justice Nelson held that substituting clay for metal or wood does not in itself deserve a patent. His analysis was that if such a trivial change was granted a patent, it would hinder the promotion of the sciences rather than benefit it. In light of this, I would argue that Jupp and Rees would not have been granted a patent for their invention for two reasons. First, the idea of a highly swept winglet was already disclosed by Ishimitsu. He discussed the benefit of sweeping a winglet to benefit from the resulting vortex flow. Even though he did not put it specifically in the context of a high lift scenario, the idea was still put forth nonetheless. The fact that Ishimitsu’s design called for the continuation of the wing rather than adding an attachment onto the wing has minimal impact at best. Justice Nelson would argue that the improvement from Ishimitsu and Vogt to Jupp and Rees was an obvious progress in the field of aerodynamics. To quote Justice Nelson “It was the work of the skillful mechanic, not that of the inventor” – Justice Nelson In the case with the A&P Tea Co., I also think that my present patent application would have got denied, for reasons already discussed. The effect of a highly swept winglet was already discussed by Ishimitsu, if by no one else. Whether or not Ishimitsu put the winglet above or below, or both, is not important, but rather trivial since the important part of his design, as quoted above, was to give the winglet a high leading edge sweep angle to garner the benefits of a vortical flow. In conclusion, I feel as though the principles put forth in both cases would stand in the way of Jupp and Rees gaining a patent for their work as it truly does not present anything new, but rather, just a trivial change from prior art.