A recent decision by the Patent Trial and Appeal Board (PTAB) addressed a dispute between GKN and JTEKT on GKN's patent (US 8,215,440) related to a vehicle drivetrain with connectable secondary axles. Claim 1 of the patent relates to:
A drive train of a vehicle, comprising a primary drive train and a secondary drive train, further comprising: a primary axle which is permanently driven via the primary drive train; and a secondary axle as part of the secondary drive train; wherein the secondary axle is connectable to the primary axle via a switch-on mechanism of a switch-on device in order to allow the integration of the secondary drive train into the drive train so that the overall drive train power is transferred over both the primary axle and the secondary axle, and wherein when the secondary axle is connected to the primary axle, the secondary drive train power is conveyed via at least one side shaft couplings into side shafts of the secondary axle and is transmitted to wheels of the secondary axle the secondary drive train having a shutdown section located between the switch-on device and the at least one side shaft coupling, whereby: the switch-on mechanism and/or the side shaft couplings comprise at least one frictionally engaged coupling and when the secondary axle is disconnected from the primary axle in order to transfer the overall drive train power via the primary axle only, the shutdown section of the secondary drive train is decoupled from both the primary axle of the primary drive train and the wheels of the secondary axle.
JTEKT attacked the patent based on several prior art references. GKN disclaimed some of the broader claims, but continued to defend some of the more narrow claims. The PTAB reached a split decision, invaliding claims 6 and 7 but finding claims 2 and 3 not invalid. Find the decision here: IPR2016-00046.
An interesting part of the case relates to the question of obviousness, for example with regard to claim 2. Claim 2 states:
The drive train as claimed in claim 1, having a side shaft coupling for each side shaft of the secondary axle and wherein when the secondary axle is connected to the primary axle, the side shaft couplings allow a driving power distribution without a differential gearing between the drive wheels of the secondary axle to ensure transverse compensation
GKN (patent owner) admitted that the combination of references showed all the elements, but contended that JTEKT did not sufficiently prove that it would be obvious to make the combination. Even though JTEKT's expert testified that the reason to make the combination would be to save weight, there was no evidence in either of the references that making such a substitution would or could save weight. The PTAB explained:
As GKN argues, Mr. Becker fails to provide any additional support for this statement. For example, Mr. Becker fails to substantiate his view that JTEKT’s proposed substitution of Watanabe’s dual clutch system for Teraoka’s single clutch and bevel gear differential would predictably result in a decrease in vehicle weight. Instead, Mr. Becker’s testimony merely mimics the language in the Petition ...
We further find that JTEKT’s citations to Mr. Becker’s deposition testimony fails to support JTEKT’s rationale for modifying Teraoka with the teachings of Watanabe. Mr. Becker’s testimony at page 94, lines 4–9, provides that general considerations in driveline design are weight and cost. See Ex. 2020, 94:4–9. Similarly, Mr. Becker’s testimony at pages 110 and 111 and 140 and 141 provides that weight is one problem to be solved in driveline design and that “cost, weight, performance, etc.” are reasons for eliminating Teraoka’s bevel gear differential, without indicating that there would be a weight savings. See id. at 110:13–111:16, 140:13–141:19. Mr. Becker’s testimony at pages 136 to 137 and 175 is equivocal and of little probative value, as he testifies that there may be a weight savings switching from a bevel gear differential to a clutch pack. See id. at 136:11–137:10, 175:14–22. That is, we find that Mr. Becker’s testimony merely emphasizes that weight is a consideration in designing vehicle components and fails to support the position that a person having ordinary skill in the art would have been motivated to implement JTEKT’s proposed modification of Teraoka with Watanabe to predictably save weight. ...
JTEKT’s position appears to be that reducing weight is a consideration in vehicle modification and, because the proposed modification may reduce the vehicle weight, that an artisan of ordinary skill would have been motivated to make that modification. Indeed, JTEKT asserts that “reducing weight and cost are recognized and implicit goals in virtually all manufacturing.” Pet. Reply 4. Following JTEKT’s reasoning to its logical conclusion, a person having ordinary skill in the relevant art would be motivated to make any modification to a manufactured item if there were a possibility that such a modification would result in a reduction of weight or cost, regardless of the probability of realizing such a reduction.
Such arguments against obviousness can be difficult before the PTAB, but as this case shows they are not unwinnable. A key here was that later in the opinion, the PTAB explains how the actual disclosure of the cited references (Teraoka and Wtanabe) actually indicate that the alleged weight savings would not be achieved by the proposed combination. JTEKT brought these issues upon itself by possibly citing too many reasons for supporting the combination.