LG Expends Significant Efforts to Secure Patent Rights on Battery Heat Exchanger

LG has a significant portfolio in the battery space, and has shown a willingness to aggressively pursue patent protection even on very specific improvements.  A recent example relates to a patent application centered on the structure of a serpentine heat exchanger (element 100 in the figures below) and an inlet tube of the heat exchanger.

Figure 7 of LG’s patent application shows a schematic of a first side of the heat exchanger 100

Figure 7 of LG’s patent application shows a schematic of a first side of the heat exchanger 100

Figure 9, a schematic of an inlet extension portion 229 including inlet tube 204 of heat exchanger 100

Figure 9, a schematic of an inlet extension portion 229 including inlet tube 204 of heat exchanger 100

LG claimed this invention as:

1. A battery cell assembly, comprising a battery cell . . . a heat exchanger . . . an inlet tube having a portion disposed within the inlet extension portion and another portion extending outwardly from the inlet extension portion . . . .

The Patent Office Examiner rejected the application, citing a prior art reference - Ouchi. Ouchi discloses flattened tubes 21 which are open at two ends and fluidically connected to headers 31 and 32.

 

Ouchi Figure 9, a perspective view of tube 21

Ouchi Figure 9, a perspective view of tube 21

Ouchi Figure 13, a front elevation of a heat exchanger

Ouchi Figure 13, a front elevation of a heat exchanger

Thus, Ouchi only discloses headers having ports 36 and 37 which are connected to heat exchanger tubes 21. The teachings of Ouchi provide no inlet tubes or inlet extension portion. The Examiner therefore relied on a secondary reference, Hoshino, which discloses tubes 11 and header 13 to allegedly provide an inlet tube disposed within and inlet extension as illustrated below.

Hoshino Figure 3, a perspective view showing the join between the header 13 and the tubes 11

Hoshino Figure 3, a perspective view showing the join between the header 13 and the tubes 11

                Hoshino, however, only provides another set of headers and heat exchange tubes which, similarly, fail to include an inlet tube.

                LG therefore appealed to the PTAB arguing that the Examiner improperly rejected the application because it was improper to rely on Hoshino in order to allege that the heat exchange tubes, soldered to a header and included within the header, disclose the inlet tube and inlet extension portion. Even assuming that the similar heat exchanging tubes of Ouchi and Hoshino (both include tubes fluidically connected to headers) were combined, LG was of the opinion that they teach totally different elements of the claims.

The PTAB, siding with LG, wisely points out that “[t]he claims require the two-walled structure with the four wrapped portions include the inlet extension. It is that structure within which the inlet tube must be disposed. The structure of Ouchi including wrapped portions is tube 21. The Examiner does not identify an inlet extension on Ouchi’s tube 21 within which an inlet tube is disposed.”

Thankfully, this board decision corrects an Examiner’s broad overreach and failure to thoroughly examine the claims as a whole and confirmed that LG was correct to fight for patent rights by appealing to the PTAB to review the Examiner’s position.