Patents Act 1977

3 (1) Any question whether an act done before the appointed day infringes an existing patent or the privileges or rights arising under a complete specification which has been published shall be determined in accordance with the law relating to infringement in force immediately before that day and, in addition to those provisions of the 1949 Act which continue to apply by virtue of Schedule 1 above, section 70 of that Act shall apply accordingly.

(2) Sections 60 to 71 above shall apply to an act done on or after the appointed day which infringes an existing patent or the privileges or rights arising under a complete specification which has been published (whether before, on or after the appointed day) as they apply to infringements of a patent under this Act or the rights conferred by an application for such a patent, and shall so apply subject to sub-paragraph (3) below, the modifications contained in paragraph 2 of Schedule 2 above and the further modification that section 69(2) and (3) above shall not apply in relation to an existing application.

(3) Where an act is commenced before the appointed day and continues to be done on or after that day, then, if it would not, under the law in force immediately before that day, amount to an infringement of an existing patent or the privileges or rights arising under a complete specification, its continuance on or after that day shall not amount to the infringement of that patent or those privileges or rights.