Fig. 3380.

In [3379] and [3380] the valve gear (which is the distinctive feature of the engine) is represented with the parts in the position they occupy when the cut off occurs at half stroke, the piston having moved from the head end of the cylinder. In [Figs. 3381] and [3382] the parts are shown in position with the crank on the dead centre and the piston at the crank end of the cylinder, valve v having opened its port to the amount of the lead.

VOL. II.THE CORLISS VALVE GEAR.PLATE XXXIV.
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Fig. 3381.

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Fig. 3382.

Referring to [Fig. 3379], motion from the eccentric is imparted by the rod m to the wrist plate y, to which are connected the rods c, c′, for operating the admission valves, whose shafts are seen at s, s′, and the rods f, f′, for operating the exhaust valves, whose shafts are seen at t, t′.

The mechanism for the steam or admission valves may be divided into three elements: first, that for operating the valve to open the port for admission; second, that for closing the valve to effect the cut off; and third, that which determines the point in the stroke at which the cut off shall occur.