Interference No. 104,190 application Serial No. 08/369,379 with its January 6, 1995 filing date. Thus, the record shows a period of inactivity of a little over 36 months. Under applicable precedent, this time period is sufficient to trigger the inference of abandonment, suppression or concealment. Accordingly, we hold that the burden has shifted to the junior party to rebut the inference with appropriate evidence. An inference of suppression or concealment may be overcome with evidence that the reason for the delay was to perfect the invention. Lutzker v. Plet, 843 F.2d 1364, 1367, 6 USPQ2d 1370, 1372 (Fed. Cir. 1988)(citing Dewey v. Lawton, 347 F.2d 629, 632, 146 USPQ 187, 189-90 (CCPA 1965)), which permitted "testing and refinement" of the invention for more than one year after reduction to practice; and Schnick v. Fenn, 227 F.2d 935, 941-42, 125 USPQ 567, 573-74 (CCPA 1960), which per-mitted a delay of about eleven months after reduction to practice while "continuing 'the development of the best design'" in further perfecting the 27Page: Previous 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 NextLast modified: November 3, 2007