By Evarist Baimu Nyaga Mawalla - Home

that at the trial the plaintiff would success in establishing his right to apermanent injunction. Cyanamid appealed.d. Held – the appeal would be allowed and the order of the patent judgerestored for the following reasons (i) The grant of interlocutoryinjections for infringement of patents was governed by the sameprinciples as those in other actions. There was no rule of law that the courtwas precluded from considering whether, on a balance of convenience aninterlocutory injunction should be granted unless the plaintiff succeeded inestablishing a prima facie case or a probability that he would besuccessful at the trial of the action All that was necessary was that thecourt should be satisfied that the claim was not frivolous or vexatious i.e.that there was a serious question to be tried see p 508 j to p 509 a, p 510b to d and f and p 512 f to j, post). (ii) The affidavit evidence showed thatthere were serious question to be tried and hat it was therefore necessarythat the balance of convenience should be considered.e. The factors which the judge had properly taken into account in consideringthe balance of convenience were that Ethicon which had a dominantposition in the market for absorbable surgical sutures, had not yet putXLG sutures on the market whereas Cyanamid were in the course ofestablishing a growing market in PHAE sutures in competition withEthicon’s catgut sutures; if Ethicon were allowed to market XLG sutures,Cyanamid if ultimately successful in proving infringementf. Would have lost its chance of continuing to increase it share in the totalmarket for absorbable sutures. There were no grounds for interfering withthe judge’s assessment of the balance of convenience or with thediscretion that he had exercised in granting the injection (see p 511 g top 512 j, post)NotesFor the principles governing the grant of interlocutory injunctions see 21halsbury’s laws )3 rdEdn) 364-366 paras 763-766 and for cases on the subject see 28 (2)Digest (Reissue) 968-9806j-161g. For interlocutory injunction to restrain infringement of patent, see 29Halsbury’s lawa )rdEdn) 105 para 216 and for cases on the ground for granting or refudininterlocutory injunction, see 26 Degest (Repl) 979-987, 3229-3317.Cases referred to in opinionsDonmar Production ltd v Bart (1964) (1967) 2 All ER 338, (1967) I WLR740, Digest (Cont Vol C) 174, J3ia298