770 , fZOSSAI. mUPOBTXB. �edges of the valve were made to curve sliglitly downward, so tbat. the steam, ou issaing betwecn the valve and its seat, would impinge against the curved projeoting portion of the valve, and would be deflected into an annular chamber which Buriounded the pjcntral passage for the steam. He said that he thus made use of the recoil action of the steam against the valve, but he gave notice that he did not claim broadly this use of the recoil action, and of the extension of the valve laterally bexp»,d its ^^eat. In fact, these two fea- tures were found in Beyer'a patent, which was issued a few months earlier ithan Naylor's. Ashcroft, the assignee of Naylor, was less modest. When he re-issued the patent he olaimed the valve with its downward curved lip, and the annular recess, adding, by way of caution, "substantially as described." The courts held that, in view of what Beyer had described and patented, Naylor could not sustain abroad claim to a curved lip or an annular recess, generally, but must be limited to his own peculiar form of construction. �Eichardson's patent of 1866 embodied the same general mode of construction and operation as was shown in Beyer and Naylor, and in other patents now produced in evidence. Judge Shepley thus describea it : �"In the Richardson valve, wh^n the valve opens, the steam expands and flows into the annular space around the ground joint. Its free escape is prevented by a stricture, or narrow space formed by the edge of the lip and the valve seat. Thus, the steam esoaping from the valve is made to act by its expansive force upon an additional area outside the valve proper, to assist in raising the valve ; this stricture being enlarged as the valve is considerably lifled from its seat, and varying in size as the quaa-' tity varies of the issuing steam." 1 Holmes, 369. �The difficulty to be overcome in all these valves which use an additionallifting area after the valve is open, is to Umit the lift so that too muoh steam shall not escape. It seems that Eichardson's valve accomplished this by a careful adap- tation of the width of his opening, or stricture, to the size of his chamber and the strength of his spring. ' In the reported case Judge Shepley said, and Mr. Justice Clififord, in the supreme court, agreed with him, that Eichardson had suc- ceeded in making a working valve of this kind which would lose but two and a half pounds when blowing off at a pressure ��� �
