Intellectual property — patents — short-term patent — construction of patent — whether invalid by reason of insufficiency — test for determining sufficiency
P was the registered owner of a Hong Kong short-term patent (the “Patent”) for a “rotator and wedge” method of extracting building piles from the ground (the “Method”). D1 awarded a subcontract to P to remove 364 H-piles at a MTR station (the “Site”) for the High Speed Railway between Hong Kong and mainland China (the “Project”). P engaged D2 as a subcontractor to supply equipment and operators for the pile removal works at the Site. Subsequently, D1 considered terminating the subcontract due to slower than expected progress. P eventually obtained the Patent. Following further contractual disputes, D1 terminated the subcontract with P, engaged D2 directly to provide machinery and operators and continued to remove the H-piles at the Site allegedly using the Method employed by P. P commenced patent infringement proceedings against Ds. The key concepts of the Method were the use of a wedge as a jamming and immobilising device between the pile and the internal surface of the steel casing; and the trapping of the pile inside the casing, which rotated, causing the pile to twist and to break at a predetermined point. Ds argued that inter alia the Patent was invalid due to insufficiency, as the description of the patented process in the search report by a designated patent office filed by P was different from the Method claimed in that the wedge was used as a cutting rather than a jamming device. D also denied infringement, arguing that the Patent specifically referred to the use of a circular wedge, whereas the pile removal works performed by D1 used only a star-shaped wedge.
Held, dismissing the action, that:
- Short-term patents were governed by s. 113 of the Patents Ordinance (Cap. 514). Under s. 117, the Registrar shall examine only whether a short-term patent application satisfied the “minimum requirements” and the “formal requirements” respectively provided for in ss. 114 and 115 of the Ordinance and not the validity of the patent.
- In determining the sufficiency of the specification, the question was whether it disclosed a sufficiently clear and complete invention which could be performed by a competent person skilled in the art without undue burden. As for errors in a specification, a specification was sufficient if the skilled addressee could rectify the mistakes and supply the omissions without the exercise of any inventive faculty.
- Here, the Patent was invalid due to insufficiency. Essential particulars were missing from the specification and a combination of six factors invalidated the Patent. First, the use of a wedge as a jamming and immobilising device was the key concept of the patented process, but the Patent did not specify whether the circular wedge was used as a cutting or a jamming device. Second, the specification did not state what caused the wedge to rotate inside the casing. Third, the reference to the circular shape of the wedge was confusing. Fourth, the diagrams relating to the Patent were confusing as they did not suggest the wedges were used as a jamming device; and did not depict the key concept of trapping the pile inside the casing, as alleged by P. Fifth, the Patent stated the Method could be used for the extraction of both bored piles and H-piles, but persons skilled in the art would be confused as to the exact process identified in the Patent which would fit both kinds of piles. Sixth, there were numerous flaws in the description of the patented process in the Patent. Even a person skilled in the art using his common general knowledge, would have difficulty ascertaining the exact invented process covered by the Patent. Thus, the alleged invention had not been disclosed clearly and enough for it to be performed by a person skilled in the art without undue burden.
- If this finding were wrong, it was relevant that the description of the patented method in the search report was inconsistent with that of the specification of the Patent. As such, the search report filed by P was defective because the prior art search was conducted on the basis of the understanding of the Patent as described by the examiner, and this was different from the Method claimed by P. Consequently, the Patent was not a valid patent covering the rotator and wedge method.