[1448]. Joy’s valve gear, operated by a pin on the connecting rod. The slotted T lever is connected to the hand lever for reversing, and when reversed stands at the same angle from a vertical line but on the opposite side. The fulcrum of the valve rod lever has a sliding motion in the slot of the T lever.

[1449]. Variable expansion gear by hand power. There are many applications of this type used to vary the travel of a cut-off valve.

[1450]. Corliss valve gear, operated by a single eccentric, has two steam and two exhaust valves similar to [No. 1642], worked from pins on a rocking wrist plate. The steam valves have trips, regulated by the governor, on a similar principle to [No. 1445].

[1451]. Crank shaft governor with shifting eccentric: the centrifugal action of the weights, acting against springs, is used to revolve the inner eccentric so as to vary the throw of the main eccentric from which the slide valve is driven.

[1452]. Another form: in this also the throw of the eccentric is varied by the action of the governor ball.

[1453]. Another form of automatic governor expansion trip gear in connection with Cornish valves; a single eccentric operates the four valves, and the contacts of the catches and steam valve levers are regulated by the governor, the lower or exhaust valves having a constant motion.

[Larger plate.]

[1454]. Double angular slide valve for varying the cut off by a transverse motion given to the valve from outside, either by hand gear or by the governor, the valve being made wider than the valve face, as dotted lines.

[1455]. H. Jack’s variable expansion gear, with one eccentric. Patent No. 4167/85.