IMPROVEMENTS IN ARRANGING AND WORKING STEAM ENGINE VALVES
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Stewart Clark at the Office of
the Commissioners of Patents, with his Petition, on the 10th July
1866. A communication from abroad by John Morris Phillips and
Joseph Hewes, residing at Newark, New Jersey, United States of
America.
I, STEWART CLARK, of Seedhill, Linside, and Cumberland Mills, Paisley,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
ARRANGING AND WORKING STEAM ENGINE VALVES," to be as follows:-
This Invention has for its object improvements in arranging and working
steam engine valves. The improvements are illustrated in the Drawings
hereunto annexed.
Figure 1 shews a side elevation of one end of a cylinder engine bed and the
steam valve movement; Figure 2, a half section through the centre of steam
port; Figure 3, a section through the centre of valve movement; Figure 4, a
side elevation of valve movement shewing the position of the regulating toe
when the balls of the governor are at their lowest point; Figure 5, a side
elevation of valve movement showing the position of regulating toe when the
balls of the governor are at the highest point. The same letters refer to the
same parts in all the Drawings.
A is the cylinder; B, the outside steam passage connecting the valve boxes
at each end of the cylinder; C, the valve box; D, valve box cap; E, valve
rod stuffing box; F, valve rod and valves; G, engine bed; H, valve movement

page_text: box; I, slide block; J, crank pin; K, crank pin box; L, cut-off toe; M,
regulating toe; N, N, are the gears by which the regulating toes M are
connected to the governor by the shaft O; P, spring for forcing down the
valves; Q, screw and nuts for adjusting the power of the spring; R, crank
shaft; S, collar in valve chamber; T, screw for fastening the collar S;
U, valve chamber and steam port.
The first part of this Invention consists in operating the valve by means of
the revolving crank J, which has double the throw required to lift the valve
its proper height; as the crank J revolves it gives a vertical motion to the
slide block I, which has connected to it the cut-off toe L; the cut-off toe L is
also connected to the crank pin box K by means of the pin V, and receives
thereby a horizontal motion equal to the throw of the crank K. The governor
attachment consists in the regulating toe M and gears N, N, which are
operated by the governor in the usual manner through the shaft O, and when
the balls of the governor are at their lowest point the regulating toe M is
thrown forward (see Figure 4) allowing it to rest on the cut-off toe L
throughout the entire stroke of the piston, and allowing steam to follow full
stroke; as the balls of the governor diverge the regulating toe M is with-
drawn, allowing the valve to fall and cutting off the steam; when the governor
balls are at their highest point the regulating toe M is so far withdrawn
(see Figure 5) that the cut-off toe L may receive its motion without touching
the regulating toe M, and the valve is not opened.
The second part of this Invention consists in placing in the valve chamber
the collar S for the purpose of occupying the space in the steam passage
which is not required after the lower valve is in its place; the collar S is held
in its place by the screw T, and has a hole in it large enough to allow the
valve stem F to work freely through it, and is for the sole purpose of reducing
the quantity of steam which is necessarily thrown away at each stroke of the
piston.