The appellant is the registered legal owner of Letters Patent No.21809/25 of the Commonwealth of Australia. His appeal is by special leave against a judgment of the High Court of Australia which affirmed a decision of the Commissioner of Patents dismissing an application of the appellant for leave to amend the specification and drawings of his Letters Patent. The patent law of the Commonwealth is regulated by the Patents Act, 1903-21. By S.71 of the Act an applicant or a patentee may by request in writing left at the Patent Office seek leave to amend his complete specification by way of disclaimer, correction, or explanation stating the nature of the amendment and the reasons for it. The next succeeding sections up to and including 79 regulate the proceedings following upon an application under S. 71 and in particular S.78 of the Act provides that no amendment shall be allowed that would make the specification as amended claim an invention substantially larger than or substantially different from the invention claimed by the specification before amendment. The original specification of the patent in question was headed "improvements in paper bags." It contained the following description of the invention. (Their Lordships gave the details and specifications of the patent and the claims and proceeded.) The application for the patent in question was dated 17th February 1925 and acceptance was on 13th July 1925. On 7th November 1929 the appellant being then registered owner of the patent applied to amend the specification and drawings, his reasons for making the amendment being stated in the following words:
"To disclaim certain parts of the invention claimed, to disclaim an alternative form of the invention as illustrated in figure 8 of the drawings and described in the letterpress relating to the said figure 8, to better explain certain particulars of the invention, to delete certain claims, to omit the said figure 8 of the drawings and the said letterpress relating to the said figure 8 and to make consequential variations in the text to the specification."
The amendments applied for were very extensive. Substantial portions of the body of the specification were practically re-written, the whole of the 28 claims were struck out and figure 8 of the drawings and the relevant part of the text of the specification relating thereto were eliminated. 12 claims were substituted for the original 28 claims. The Commissioner of Patents refused the application on the ground that the amendments practically amounted to the re-writing of the whole of the specification and the formation of a new claim. An appeal to the High Court failed upon the ground that the amendments would have made the specification as amended claim an invention substantially different from the invention claimed by the specification before amendment.
At the date when the application for amendment was launched there was no action for infringement or proceeding for revocation pending but after the decision of the High Court the respondents, Paper Sacks Proprietary, Ltd., instituted proceedings for the revocation of the Letters Patent. Such proceedings were stayed pending the determination of the appellant's present appeal against the decision of the High Court. After the matter had been opened before their Lordship's Board the appellant's counsel under pressure of the criticisms levelled against his amendments asked leave to substitute some new amendments in place of his original amendments. The application was opposed by the respondents who urged that having regard to Ss. 80 and 81 there was no jurisdiction in their Lordships Board to grant the application and such leave could only be given by the Judge having seisin of the revocation proceedings. The two sections in question are in the following terms:
"80. Except as provided in the next following section the provisions of Ss. 71 to 79 do not apply when and so long as any action for infringement or proceeding for revocation of a patent is pending.
"81. In an action for infringement of a patent and in a proceeding for revocation of a patent the Court Justice or Judge may at any time order that the patentee shall subject to such terms as to costs or otherwise as the Court Justice or Judge may impose be at liberty to apply under the last preceding section for leave to amend his specification by way of disclaimer and may direct that in the meantime the trial or hearing of the action be postponed."
Now it was not disputed that upon an application properly instituted under S. 71 any Court having seisin of the matter would be free if no such proceedings as are mentioned in S. 81 had in the meantime been begun and remained pending to give leave to the applicant to modify his amendments and if thought proper to sanction the modified amendments but it was urged that this power ceased the moment any proceeding of the kind mentioned in S. 81 was launched. Their Lordships were unable to accept the view urged by the respondents upon the effect of Ss. 80 and 81. In their Lordships' judgment it is not the result of these sections that any limitation is imposed upon the jurisdiction of a Court having seisin of an application properly launched under S. 71 because at some date subsequent to the application under S. 71 an action for infringement or a proceeding for revocation has been instituted.
Taking this view of the matter their Lordships authorized the appellant to bring in new amendments upon the footing that success on the new amendments would not improve his position in the matter of costs. In these circumstances it was unnecessary for their Lordships to express any opinion upon the original amendments and the new amendments became the sole matter for consideration. (Their Lordships then gave the details of the amendment sought, the reasons urged for and against it and proceeded.) Now an applicant for amendment has upon him the burden of showing that his amendment falls within one or other of the three categories of disclaimer, correction, or explanation add that he is not claiming an invention which is substantially larger than or different from that originally claimed. This necessarily involves that his amendment must be unambiguous otherwise the onus upon him cannot be discharged.
It has been said that the number of combinations possible under the claims of the original specification is so great that the selection of one of them is an operation of such complication and difficulty as in itself to amount to new invention or at any rate to something more than disclaimer of all the combinations other than the one selected. Their Lordships do not think it necessary to express any view upon the question of invention by selection or upon the question whether the number of combinations possible under the original specification can make any difference in principle to the power of disclaimer. It is enough for the purpose of the present appeal to say that in their Lordships' judgment the language of claim 1 of the new amendments is of import too doubtful to enable the appellant to discharge the onus that is upon him. He fails in their Lordships' opinion to establish with sufficient certainty either that this claim is merely one of those already covered by some one or more of the old claims upon which he relies or that it does not comprise an invention substantially larger than or substantially different from that covered by the unamended specification. (Their Lordships then gave reasons for holding as above and held.) The body of the specification under the new amendments (restored as it thereby is substantially to its original condition) when read with claim 1 of the new amendments introduces in their Lordships' opinion such elements of inconsistency and doubt as make it impossible to accept the view that the appellant has discharged the onus upon him. (Their Lordships allowed certain minor amendments and advised dismissal of appeal with costs.)