ANDREW BETTS BROWN AND BROWN BROTHERS & Co., LD.V. JOHN HASTIE & CO., LD
Reports of Patent Design and Trade Mark Cases
Pioneer or Master Patent.-Oombination of known mechanical appliances. for a neio purpose.-Essence and substance of invention.-Construction of 10 Spec1fication.-Claim.-Infringement. Stearn is admitted to steering enqine« by a controlling valve, tohich. 1;S shut iohen the engine lis at rest. Means had long been sought to prevent leakage through the controlling valve when shut. In 1897 a Patent was granted to B., the object 0/ which he described as follouie :-" To prevent or considerably 15
... siderably 15 "di'minish the leakage of steam hereinbefore referred to. For this purpose I "fit in a passaqe or casing through which the steam enters the controlling " valve casing a double-beat valve which has formed or fiaed on it oppositely " inclined surfaces which are acted upon by counterpart inclines fitted in " connection with the controlling valve, so that 01~the mooemen t of the controlling 20 "valve it acts through the inclined surfaces to open the double-beat valve and " admits steam." The Patentee added :-" Instead of the equilibrium valve A " (the double-beat valve) " any equivalent device may be used. For example; the " inclines mas] be on the stern of a small valve which opening first admits the " steam under a larger valve opened by the further motion of the small valve." 25 He claimed :-" In connection with the valves of steering and like eng'ines,jitting " in a passage or casing, through uihich. the steam enters the controlling valve H casing, a, double-beat or equivalent valve having opposite inclines acted on by "counterpart inclines moving with the controlling valve, the paris being " arranged and operatiru) s'ubstantially as and f01' the purposes hereinbefore 30 "described." The double-beat valve used as a stop valve was a uieli-knoum mechanical device. It had been applied in continuous engines to work automatically ioith. the distribut~ng valve so as to cut off the steam from the distributing valve casing during a part of each stroke. It had never been applied to the controlling ualues of steering enqinee, nor had the leakiness of 35 these valves been successfully remedied 'in any other UJCl,Y. by Held (affirming the judqment of Kyllachy, L.O.), that 'in construing the SlJecification it must be considered what,_having regard to the state ofprior knowledge, was the field open to the inventor; that in the circumstances the Patent was a pioneer or master Patent; that it was not to be constru-ed as claiming only the double-beat valve actuated by inclined planes slid'ing on counterpar t inclines, 5 but as claiming the application to steering and the like engines, for the purpose of preventing leakage of steam while the engine 1:S not working, of a separate stop valve working in unison with the controllinq valve.