General grounds for cancellation.
Section 28
SEC. 28. General grounds for cancellation.—Any person may on payment of the required fee petition the Director within three years from the date of publication of the issue of the patent in the Official Gazette, to cancel the patent or any claim thereof, on any of the following grounds: (a) That the invention is not new or patentable in accordance with section seven, eight and nine, Chapter II hereof; (b)That the specification does not comply with the requirement of section fourteen, Chapter III hereof; or (c) That the person to whom the patent was issued was not the true and actual inventor or did not derive his rights from the true and actual inventor.