There were two suits in this case. One by the plaintiff Bajaj Auto Limited which filed a suit under Section 108 of the Patents Act, 1970 for the relief of permanent injunction in respect of the plaintiff’s patent and/or from using the technology/invention described in the said patent and/or manufacturing, marketing, selling, offering for sale or exporting 2/3 wheelers, including the proposed 125-CC FLAME motorcycle containing an internal combustion engine or any internal combustion engine or product which infringes the plaintiff’s patent claiming of damages for infringement of patent etc. Pending the said suit, the plaintiff prayed for an order of temporary injunction restraining the respondent from in any manner infringing the applicant’s patent.
Plaintiff in another suit, TVS Motor Company filed the suit on the basis of groundless threat of infringement under Section 106 of the Patents Act, for declaring that the threats held out by the defendant that the plaintiff is infringing the defendant’s patent and that the defendant is proposing to take infringement action against the plaintiff are unjustified and also for permanent injunction restraining the defendant from continuing the issuance of threats and thereby interfering with the launch and sale of product TVS Flame apart from directing the defendant to compensate the plaintiff by way of damages sustained on account of the unjustified threats made by the plaintiff. Pending the said suit, the plaintiff filed for an order of interim injunction restraining the respondent from interfering with the manufacture and marketing of applicant’s products.
Except the use of three valves, the product which was attempted to be marketed by the respondent was prima facie similar to the applicant’s patented product.
Issue: Whether the Defendants infringed the patent or combination even though it made some improvements to the main patented article?
They have infringed the patent if they have used that combination. If they have used that combination, and also something added to it, that combination remaining a necessary part of their machine, but the addition to it being an improvement, without acknowledgement that they are only using an improvement, then that would be an infringement.
If they had invented such a machine, they would have been entitled to take out a patent, not for that machine as a new machine, but for an improvement upon the Plaintiffs’ machine. If they had claimed the improvement on the Plaintiffs’ machine, they could not use their improved machine without paying the proper price to the Plaintiffs for having used their machine although improved. If they used it without paying, they would infringe.
Therefore, the defence of variant must be real and essential to the features and purpose of plaintiff’s product.
The Court in this case observed that while deciding the test for variant three questions have been raised and answered by the English Court in Improver Corporation and Ors. v. Remington Consumer Products Ltd. and Ors., which are as follows:
The proper approach to the interpretation of patents registered under the Patents Act 1949 was explained by Lord Diplock in Catnic Components Ltd. v. Hill & Smith Ltd. The language should be given a “purposive” and not necessarily a literal construction. If the issue was whether a feature embodied in an alleged infringement which fell outside the primary, literal or a contextual meaning of a descriptive word or phrase in the claim (“a variant”) was nevertheless within its language as properly interpreted, the court should ask itself the following three questions:
(1) Does the variant have a material effect upon the way the invention works? If yes;, the variant is outside the claim. If no –
(2) Would this (i.e. that the variant had no material effect) have been obvious at the date of publication of the patent- to a reader skilled in the art. If no, the variant is outside the claim. If yes –
(3) Would the reader skilled in the art nevertheless have understood from the language of the claim that the patentee intended that strict compliance with the primary meaning was an essential requirement of the invention. If yes, the variant is outside the claim.
The Court subsequently in para 54 observed that-
“It is also clear as per the decisions, for the purpose of deciding the novel features to constitute “pith and marrow” a purposive construction has to be given in order to make it essential requirement of the invention that any variant would follow outside the monopoly even if it could not have material effect upon the working of invention.”
 1990 FSR 181