. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . s thelever forward the instant the latch is re-leased. Now consider the lever locked inposition. The latch on the sector acts asa fulcrum, and the reaction on the pivotof the reverse lever is 159 lbs., while thereaction on the latch is lbs. Again,consider the lever as being pulled the reach rod is a fulcrum, and, with278 lbs. on the end, the reaction on thepivot is 494J4 lbs. In practice these forcesare supposed to be taken up by the coun-terbalance spring, but they should be
. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . s thelever forward the instant the latch is re-leased. Now consider the lever locked inposition. The latch on the sector acts asa fulcrum, and the reaction on the pivotof the reverse lever is 159 lbs., while thereaction on the latch is lbs. Again,consider the lever as being pulled the reach rod is a fulcrum, and, with278 lbs. on the end, the reaction on thepivot is 494J4 lbs. In practice these forcesare supposed to be taken up by the coun-terbalance spring, but they should be con-sidered in the design to allow for emer-gencies. There is another force acting on the re-verse lever when it is operated with the• engine under steam. Assume the link inFig. 2 to move from full gear forwards tofull gear back. The* link block will movein the slot from B to A, or a horizontaldistance equal to C A. At the same timethe point of suspension will move a verti-cal distance equal to C B. This is equiva-lent to moving the weight on the valve upan inclined plane, B A. By the usual rule. ESSENTIAL PARTS OF VALVE GEAR. the power required equals the load on thevalve multiplied by the distance A C, anddivided by C B. This, of course, is a veryrough calculation, as the link is constantlychanging its position, and the powerchanges with the angle, but it serves toshow the effect of moving the valve onhandling the reverse lever when the en-gine is using steam. The small rectangle at the bottom of thelink will illustrate another force actingthrough the link on the reverse lever. Thefigure is not drawn to scale, but it maybe constructed for any given case as fol-lows : From the eccentric rod pin, D, con-tinue the line of motion of the rod to F,making D F equal to the force acting at D. Complete the parallelogram so that tliesides D E and F G are parallel to the linkarc, and the sides E F and D G arc parallelto the motion of the end of the link. Nowthe force D F is broken into
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