
182 S.E.2d 839 (1971)
12 N.C. App. 199
Reginald S. HAMEL, Ancillary Administrator of the Estate of William Thomas McDowell, Jr.
v.
YOUNG SPRING & WIRE CORPORATION, a Michigan Corporation et al.
No. 7126SC363.
Court of Appeals of North Carolina.
August 18, 1971.
Certiorari Denied October 5, 1971.
*842 Claude R. Dunbar, Spartanburg, Hunter M. Jones, Charlotte, for plaintiff appellant.
Carpenter, Golding, Crews & Meekins, by John G. Golding, and Michael K. Gordon, Charlotte, for defendant appellant-appellee, Twin-States Truck Equipment Co.
John H. Small, R. C. Carmichael, Jr., Charlotte, for defendant appellees, Young Spring & Wire Corp., Paul Hardeman, Inc., and Daybrook-Ottawa Corp.
Certiorari Denied by Supreme Court October 5, 1971.
CAMPBELL, Judge.
Plaintiff assigns as error that portion of the charge to the jury that defendants were not required to anticipate negligence on the part of Duke in maintaining and servicing the Strata-Tower. We are of the opinion that this portion of the charge was proper and correct. To hold that defendants had to anticipate negligence on the part of Duke in maintaining the Strata-Tower would impose an improper burden. In effect, it would mean that manufacturers would have a duty to oversee the maintenance and servicing of all equipment manufactured and sold by them, wherever situated; otherwise they might be held liable for injuries resulting through no defect in the manufacture of the equipment but through the negligence of a third party in the maintenance of the equipment. Generally, "`one is not under a duty of anticipating negligence on the part of others, but in the absence of anything which gives or should give notice to the contrary, *843 a person is entitled to assume, and to act upon the assumption that others will exercise care for their own safety.'" Hawes v. Atlantic Refining Co., 236 N.C. 643, 74 S.E.2d 17 (1953).
Negligence by a third party in maintaining or servicing equipment is to be distinguished from negligence by a third party in failing to discover a negligently manufactured part. In the latter case, the negligence of the third party in failing to discover the defect does not intervene and supersede the original negligence of the manufacturer. Gwyn v. Lucky City Motors, Inc., 252 N.C. 123, 113 S.E.2d 302 (1960). But that is not the situation here in reference to that portion of the charge complained of. "* * * A manufacturer does not warrant that his product is incapable of deteriorating into a dangerous state if mishandled or kept too long before being used. * * *" (Emphasis added) Terry v. Double Cola Bottling Co., 263 N.C. 1, 138 S.E.2d 753 (1964), concurring opinion by Sharp, J.
Plaintiff also contends that the trial judge erred in charging the jury as to the duty of the manufacturer. That portion of the charge was as follows:
"Members of the jury, I instruct you that the manufacturer of a machine which is dangerous because of the way in which it functions and patently so, owes to those who use it a duty merely to make it free from latent defects or defects which are concealed danger. So in a case such as this the plaintiff must prove the existence of a latent defect or a danger not known to the plaintiff or other users of the Strata-tower in question."
The North Carolina Supreme Court approved of the same language used in the charge above in the case of Kientz v. Carlton, 245 N.C. 236, 96 S.E.2d 14 (1957). No error is found to appear.
Plaintiff makes other assignments of error to the charge. We have considered each of these assignments of error and find that the charge, considered in its entirety, was fair and free from prejudicial error.
Plaintiff also assigns as error the exclusion of testimony by employees of Duke as to the safeness of the Strata-Tower. Such testimony calls for the opinion of the witnesses, yet none of the witnesses had been tendered or qualified as an expert. When an objection to such testimony is made, the proper procedure is for the party offering the witness as an expert to request a finding of his qualification; absent such a request and absent a finding or admission that the witness is qualified, the exclusion of his testimony will not be reviewed on appeal. State Highway Commission v. Matthis, 2 N.C.App. 233, 163 S.E.2d 35 (1968); Stansbury, N.C. Evidence 2d, § 133. The competency of a witness to testify as an expert is a question addressed to the sound discretion of the trial judge, and his discretion is ordinarily conclusive. State Highway Commission v. Matthis, supra. No question of abuse of discretion is raised and none is found.
We note that at the close of all the evidence the trial judge withheld a ruling on the motion of Daybrook for a directed verdict and did not rule on this motion until after the jury verdict. We do not approve of this procedure and think it preferable to rule upon a motion for a directed verdict prior to the submission of a case to the jury. After a case has been submitted to a jury, the proper motion to be ruled upon at that time is a motion for judgment notwithstanding the verdict under Rule 50.
The other assignments of error have been considered, but we are of the opinion that the trial was free of prejudicial error.
In light of the disposition of this case, we do not deem it necessary to discuss the appeal of the defendant Twin-States from *844 the denial of its motion for a directed verdict against Daybrook on its cross-action for indemnity on the implied warranty.
Affirmed.
MALLARD, C. J., and HEDRICK, J., concur.
