(3) No suit shall be brought for any infringement of a patent granted under this section committed before the actual date on which such patent was granted.
53. Term of Patent
(1) Subject to the provisions of this Act, the term of every patent granted under this Act shall -
- a. in respect of an invention claiming the method or process of manufacture of a substance, where the substance is intended for use, or is capable of being used, as food or as a medicine or drug, be five years from the date of sealing of the patent,
or seven years from the date of the patent whichever period is shorter; and
- b. in respect of any other invention, be fourteen years from the date of the patent.
(2) A patent shall cease to have effect notwithstanding anything therein or in this Act on the expiration of the period prescribed for the payment of any renewal fee, if that fee is not paid within the prescribed period or within that period as extended under this section.
(3) The period prescribed for the payment of any renewal fee shall be extended to such period, not being more than six months longer than the prescribed period, as may be specified in a request made to the Controller if the request is made and the renewal fee and the prescribed additional fee paid before the expiration of the period so specified.
CHAPTER IX
PATENTS OF ADDITION
54. Patents of addition
(1) Subject to the provisions contained in this section, where an application is made for a patent in respect of any improvement in or modification of an invention described or disclosed in the complete specification filed therefor (in this Act referred to as the "main invention") and the applicant also applies or has applied for a patent for that invention or is the patentee in respect thereof, the Controller may, if the applicant so requests, grant the patent for the improvement or modification as a patent of addition.
(2) Subject to the provisions contained in this section, where an invention, being an improvement in or modification of another invention, is the subject of an independent patent and the patentee in respect of that patent is also the patentee in respect of the patent for the main invention, the Controller may, if the patentee so requests, by order, revoke the patent for the improvement or modification and grant to the patentee a patent of addition in respect thereof, bearing the same date as the date of the patent so revoked.
(3) A patent shall not be granted as a patent of addition unless the date of filing of the complete specification was the same as or later than the date of filing of the complete specification in respect of the main invention.
(4) A patent of addition shall not be sealed before the sealing of the patent for the main invention; and if the period within which, but for the provisions of this sub-section, a request for the sealing of a patent of addition could be made under section 43 expires before the period within which a request for the sealing of the patent for the main invention may be so made, the request for the sealing of the patent of addition may be made at any time within the last mentioned period.
55. Term of Patents of addition
(1) A patent of addition shall be granted for a term equal to that of the patent for the main
