Appeal from concurrent decisions of the Patent Office tribunals in an interference proceeding awarding priority of invention to Alfred H. Dyson, the senior party.
The invention relates to improvements in automatic telephone sys-. terns, and the issue is expressed in 11 counts. Each of the -three tribunals of the Patent Office found that appellants had failed to establish conception of the invention prior to Dyson’s filing date. The *987Examiner of Interferences made no finding on the question of diligence, but the Examiners in Chief and the Assistant Commissioner found that, even assuming prior conception on the part of appellants, the result would be the same, because appellants had failed to show diligence in reducing the invention to practice.
Appellants’ contentions have been very thoroughly and ably presented, both by brief and argument, but, having in mind that appellants are the junior parties and that there are three concurrent decisions against them, we are not so clearly convinced that the ruling of the Patent Office on the question of diligence was erroneous as to feel warranted in reversing the case on that point. There was a period of several months of inactivity at a critical period, or just before and after Dyson entered the field, and the circumstances were such that we are unable to say that the Patent Office clearly was in error in ruling that this delay constituted lack of diligence. It is unnecessary, therefore, for us to make any finding on the question of priority of conception, and we express no view thereon.
The decision must be affirmed.
Affirmed.