This is a suit for patent infringement in which plaintiff has charged defendants with the infringement of plaintiff’s patent relating to cans containing a starting fuel for diesel engines. Defendants, by counterclaim, have charged plaintiff with infringement of their patent. Plaintiff noticed the depositions of two witnesses who are employed by Pace, Inc. This company now packages plaintiff’s starting fluids. The witnesses appeared voluntarily on behalf of plaintiff, and on direct-examination testified as experts and gave opinion testimony against the validity of defendants’ patent. On cross-examination by the defendants’ attorney, these witnesses refused to answer all questions relating to the formulation of the spray starting fluid packaged for plaintiff and the method employed by Pace in loading the packages for plaintiff.
The witnesses asserted that their counsel had advised them not to answer questions relating to the business of Pace. On argument of this motion, plaintiff has taken the position that the questions propounded by defendants were not within the scope of the direct examination and, therefore, were not permissible cross-examination.
In our opinion, these questions are certainly relevant to the subject matter of this action. As to the argument that the questions did not come within the scope of the direct examination, it is enough to note that Rule 26(f) of the Federal Rules of Civil Procedure, 28 U. S.C.A. provides that:
“A party shall not be deemed to make a person his own witness for any purpose by taking his deposition.”
Professor Moore, commenting on this Rule, says:
“Moreover, if the party taking the deposition examines the deponent only as to one issue in the case, it would seem that another party may examine the deponent on any other issues by direct examination without the necessity of serving a prior notice of the taking of deposition. In so doing, he does not make the deponent his witness.” Moore’s FEDERAL PRACTICE, Vol. 4, p. 1185.
We agree with Professor Moore that, the ordinary trial limitations on the scope of cross-examination are not grounds for *213a witness refusing to answer a question asked during the taking of his deposition for purposes of discovery.
ORDER
And now, to wit, this 13th day of July, 1962, It Is Hereby Ordered that the witnesses Ira A. Wolfson and Morris H. Unthank appear at a time and place designated by defendants’ attorney for the purpose of answering the questions listed in defendants’ amended motion..