. Railway mechanical engineer . de valvegear for locomotives having an eccentric rod driven by a returncrank and constrained at an intermediate point by a radiushanger suspended by a curved guide, the free end of the eccen-tric rod being operatively connected to a bell-crank sustainedby the guide yoke. This was described by Charles Brown onpage 271 of the October 1, 1880, issue of Engineering (Lctndon).A description of a similar gear prepared by the writer waspublislii-d in tlic RiiUrond Ca::cltc, issue of May 20, 1903, page termined, the points F and /• showing the location of the radiushange
. Railway mechanical engineer . de valvegear for locomotives having an eccentric rod driven by a returncrank and constrained at an intermediate point by a radiushanger suspended by a curved guide, the free end of the eccen-tric rod being operatively connected to a bell-crank sustainedby the guide yoke. This was described by Charles Brown onpage 271 of the October 1, 1880, issue of Engineering (Lctndon).A description of a similar gear prepared by the writer waspublislii-d in tlic RiiUrond Ca::cltc, issue of May 20, 1903, page termined, the points F and /• showing the location of the radiushanger connection for the two cut-oflF positions may be the length of the radius hanger and the radiusof the reverse link is now in order. The length of the radiushanger is determined by locating a point, W, which is equidistantfrom points F, F and F, the distance ]VF being the requiredlength of the hanger, and the arc Oil, struck from the point Fas a center, becomes the center line of the reverse link. Point w. Laying Out the Southern Valve Gear for Unequal Cut-offs 377. Following the gear disclosed by Mr. Brown we liave hadthe Marshall, Bremme, Klug, Wyllie, Strong and finally tlieSouthern gears, all kinematically one and the same. Referring to the Marshall gear a statement is made in the In-ternational Text Book Companys volume on steam engine andboiler design to the effect that no definite rules for its layoutcan be given. The following direct method of determining thelength of the radius hanger and the radius of the curved guidewill be of interest. It is well known that in order to equalize the amount of workdone by the two ends of the cylinder, it is necessary to maintaina higher mean effective pressure in the crank end than in tliehead end, which may be done by providing a later cut-off in thecrank end. The diagram shows a method of laying out theSouthern valve gear in order to obtain this effect, the diagrambeing constructed on the assumption of a worki
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
