CHAPTER VI GRANT, DURATION AND EFFECT OF PATENTS 44. 45. 46. 47. 48. 49. 50. 51. 52. Granting and sealing of patent Effect of patent Duration of patent Restoration of lapsed patent Rights of patentee of restored patent Joint ownership in patents Correction of clerical errors and amendment of documents Amendment of specification Rectification of register CHAPTER VIII LICENCES 53. 54. 55. 56. 57. 58. Licences of right Cancellation of endorsement on patent Compulsory licences in respect of dependent patents Compulsory licence in case of abuse of patent rights Termination of contracts relating to licences Effect of licence CHAPTER IX ASSIGNMENT, ATTACHMENT AND HYPOTHECATION OF PATENTS AND APPLICATIONS FOR PATENTS 59. 60. Assignment and devolution of patents by operation of law Assignment, attachment and hypothecation of patent or application for patent CHAPTER X REVOCATING OF PATENTS 61. 62. 63. 64. Grounds for application for revocation of patent Patents comprising more than one invention After revocation on ground of fraud inventor may obtain patent in certain circumstances Voluntary surrender of patent CHAPTER XI INFRINGEMENT 65. 66. 67. 68. 69. 69A. 70. 71. Proceedings for infringement Restriction on recovery of damages for infringement Presumptions in relation to new substances Relief for infringement of partially valid specification Declaration as to non-infringement Acts of non-infringement Remedy for groundless threats of infringement proceedings Special provisions as to vessels, aircraft and land vehicles of convention countries CHAPTER XII EVIDENCE