The following case illustrates the difficulty in being able to predict the outcome of patent litigation. It also provides hints at improving ones patent drafting technique. During patent litigation, the claim terms are construed in light of (1) the plain meaning of the terms, (2) the specification and (3) the prosecution history among other things.
In American Piledriver v. Geoquip and Bay Machinery, the patentee (Piledriver) sued two different entities (Geoquip and Bay Machinery) in two different venues or courts for patent infringement. Both courts construed the patent claims but both Courts defined the same terms differently. Nonetheless, both Courts came to the same conclusion that the defendants did not infringe Piledriver’s patent. Hence, the difficulty in predicting the outcome of patent litigation. Piledriver appealed.
In order to understand the holding of the case and possible strategies in writing patent applications, it is important to understand the patented technology, the claim language at issue and the design around employed by the defendants.
The invention relates to a vibratory pile driver. Vibration and weight of the pile drive the piles into the ground. The prior art utilized a pair of eccentrically weighted cylinders either intergral with the gear or connected to a gear. The rotational axes of the eccentric weights are horizontally lined up and rotated in opposite directions to remove any horizontal movement caused by rotation of the cylinders. Only the vertical movement is left. It is easier to understand operation of the invention by reviewing Figures 1 and 3 below.
The claims required an eccentric weight portion. Based on the consistent use of the terminology in the claims, the specification and the prosecution history, the court affirmed the definition of the term adopted by the Virginia court. In particular, the Virginia Court defined the term “eccentric weight portion” to mean “that portion of the counterweight that extends forward or rearward from the front or back face of the gear portion such that it shifts the center of gravity radially outward from the gear’s rotational axis.” (emphasis added). The eccentric weight portion is shown in Figure 3 above.
The accused infringing device is shown below. As can be seen, the weight which vibrates the gear is embedded within the gear itself. The eccentric weight does not extend forward or rearward.
PATENT DRAFTING TIPS:
Based on this case, in drafting a patent application, the drafter should consider the alternative design arounds and include them into the patent application if possible. Most reputable patent attorneys will include alternative embodiments. A balanced approach must be employed since adding too many different embodiments may unreasonably increase the cost of the patent application. However, if there is a purpose for adding various alternative embodiments exist, then they should be added.
The claim language also needs to be crafted so as to be broad enough to encompass those potential alternative design arounds. This is sometimes hard to do since you are called upon to look into the future. More importantly, even if the potential alternative design arounds are less optimal than the present invention, it may be beneficial to include the less desireable embodiment in the patent application.
I invite you to contact me with your patent questions at (949) 433-0900 or [email protected]. Please feel free to forward this article to your friends. As an Orange County Patent Attorney, I serve Orange County, Irvine, Los Angeles, San Diego and surrounding cities.