Improvements in the Construction of Corliss Valves and Trip Gear for Steam Engines.
Year: 1894

page_text: Date of Application, 28th Aug., 1894-Accepted, 6th Oct., 1894
COMPLETE SPECIFICATION.
Improvements in the Construction of Corliss Valves and Trip Gear
for Steam Engines.
We, JOSEPH POLLIT, and EUSTACE WIGZELL, Engineers, of Bank Foundry,
Sowerby Bridge, in the County of York, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
In order that our improvement may be the more clearly understood we describe
same in conjunction with the drawings annexed hereto.
From the circular valve for admitting the steam at one end of the stroke of
the piston, we have a valve rod, C. Figs. 2 and 3, formed with a jaw or slot,
A. Fig. 3, so as to allow the circular valve to come against its face, and at the
same time hold it so as to oscillate it to and fro. The underside, B, of this jaw is
made conical, the rod, C, passing through a stuffing box, the end of the liner, D.
Fig. 3, being made conical, to correspond with the cone on the underside, B, of
the jaw or slot, A.. Fig. 3, keeping it steam tight. The stuffing-box we keep steam
tight by means of woodite packings, E Fig. 3, or packings made of other suitable
material, these packings being made to fit the rod on the inside and cone shaped
on the outside, so that should there be any leakage of steam through the liner, D.
Fig. 3, it closes the cone shaped packing, E, tight on to the rod or spindle, C.
On this valve spindle or rod C, there is a cam shaped piece G, Figs. 2. and 3.
keyed on, and from this piece there is a connector, H. Fig. 3, leading to a cam
shaped piece, F. Fig. 3 placed at a given distance from the cam shaped piece G,
and formed in a radius struck from the rod C. Along the connecting piece, H.
Fig. 3, there is a hardened steel strip, I, dovetailed and bolted by two bolts, J. J.
Fig. 3. On the cam shaped piece, G Figs. 2 and 3, there is a projection, taking a
pin, K Fig. 2, towards the cam shaped piece F Fig. 3, and leading down to the
dash pot, which keeps the cam shaped piece, G Figs. 2 and 3, which is keyed to
the valve rod C, in such a position that the circular valve is closed.
The end of the valve rod C. is supported by a bracket, L Fig. 3, this bracket
being a part of the stuffing box or valve chest cover, M. Fig. 3.
The end of the valve rod C. is bushed, and outside this bush there is a double
crank N Figs. 2 and 3, with a tube shaped projection running over the bush at the
end of the spindle. This tube shaped projection works inside the bearing at the
end of the bracket L Fig. 3.
On one end of the double crank or lever, N, there is a pin, O Fig. 2, which is
coupled by a lever to a disc or double crank, a reciprocating movement being
obtained from an eccentric. The other end of the double crank or lever N, has a
latch, P Fig. 2, with a tongue like projection, Q, and on the latch P, there is a
hardened steel strip, R, corresponding with the steel strip I Fig. 3. and V'd on and
held in position by two bolts S., which works in a radius swung from the rod C.
Fig. 2. There is a spring screwed into the pin T, passing through a hole, U, in
the latch P, shown in Fig. 2, which keeps the latch downwards, and the steel
strip R. Fig. 2 against the steel strip I Fig. 3.
In between the cam shaped piece G, and the cam shaped piece F, working on
the spindle C, there is a cam shaped piece, V. Figs. 2 and 3, with a projection, so
formed that it lifts the tongue shaped piece Q, connected to the latch P. Fig. 2,
and thus releases the cam shaped piece F, the hardened steel strip R. being lifted
clear by the hardened steel strip I, and the rod K³ being brought down by the
dash pot and the valve closed

page_text: Should the dash pot fail to close the valve, on the pin K on the cam shaped
piece G, Fig. 2, and on the reverse side from the rod K¹, there is a roller, or a
projection, of a given size, taking the crank lever N, which being worked from an
eccentric, pushes the dash pot rod, K¹, down into its place as it comes into contact
with the roller or projection on the pin K.
The cam shaped piece V Figs. 2 & 3, has a projection, with a bolt, to which is
attached a disc, Y. Fig. 3, running round outside and against the cam shaped
piece G, from which a rod, W. Fig. 2, connects it to the governor.
On the disc Y, there is also a pin and a rod, A¹ Figs. 2 & 3 which connects the
cam shaped piece V, Figs. 2 & 3, with the valve on the other end of the cylinder,
Fig. 1, only, instead of being at the top of the valve spindle, as at A¹ Fig. 2, it
comes on the bottom, as shown at B' Fig. 1, thus reversing the motion, which is
regulated by a left and right handed screw C. The motion given out by the
governor rod, W, is thus transmitted through the rod and pieces to the trip gear
of the valve at the end of the cylinder, this being of a similar construction to
that shown in Fig. 2.
Fig. 4. shows the cam shaped piece G, steel strip I, cam V, disc Y, and projection
for pin K, and pin for taking rod A'.
The two exhaust valves are placed under the steam valves, the construction of
the valves being similar to that shown in Fig. 2, worked to and fro by a disc or
double crank from an eccentric, the valve rods being constructed in a similar
manner to that shown in Fig. 3, with a jaw A; a cone B, packing E, and
bracket L.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed we declare that what
we claim is :--
1. The improved construction of Corliss valves and trip gear for steam engines,
substantially as described and shown in drawings.
Dated this 28th dox of August 1894