37. Avoidance of restrictive condition in contracts.-
(1) Subject to the provisions of this section, any condition of a contract for the sale or lease of a patented article or of an article made by a patented process or for license to exploit a patented article or process, or relating to any such sale, lease or license, shall be void so far as it purports-
(a) to require the purchaser, lessee or licensee to acquire from the vendor, lessor or licensor, or his nominees, or prohibit him from acquiring from any specified person, or from acquiring except from the vendor, lessor or licensor, or his nominees, any article other than the patented article or an article made by the patented process; or
(b) to prohibit the purchaser, lessee or licensee from using articles, whether patented or not, which are not supplied by, or any patented process which does not belong to, the vendor, lessor or licensor, or his nominees, or to restrict the right of the purchaser, lessee or licensee to use any such article or process.
(2) In proceedings against any person for infringement of a patent, it shall be a defence to prove that at the time of the infringement there was in force a contract relating to the patent made by or with the consent of the plaintiff and containing a condition void by virtue of this section.
(3) A condition of a contract shall not he void by virtue of this section if-
(a) at the time of the making of the contract the vendor, lessor or licensor was willing to sell or lease the article, or grant a license to use or exploit the article or process, as the case may be, to the purchaser, lessee or licensee, on reasonable terms specified in the contract and without any such condition as is mentioned in sub-section (1); and
(b) the purchaser, lessee or licensee is entitled under the contract to relieve himself of his liability to observe the condition upon giving to the other party three months notice in writing and subject to payment to him of a just compensation.