Improvements in the Trip Motion for Corliss Valves of Steam Engines.
Year: 1888

page_text: Jate of Application, 2nd May, 1888
Complete Specification Left, 1st Feb., 1889
Complete Specification Accepted, 13th Apr.,
188
PROVISIONAL SPECIFICATION.
Improvements in the Trip Motion for Corliss Valves of Steam
Engines.
We, GEORGE GRAY RHODES of the firm of Rhodes & Critchley, of 27 Kirkgate,
Bradford, in the County of York, Consulting Engineer, and FREDERICK WILLIAM
BYWATER, of the firm of Bywater & Nephew, of Birstal Foundry, Birstal, aforesaid,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improved mechanism for the trip motion of Corliss valves:
of steam engines, and has for its object the arrangement of the whole of the apparatus
on the axis of the valve spindle.
We accomplish our object by mounting on the axis of the valve spindle, but not
secured fast thereto, an oscillating plate, and on to this plate we pivot a lever which
engages by means of a catch with a bush keyed fast to the valve spindle, whereby
as the plate is moved and the lever engages with the bush, the valve is opened. The
lever is lifted out of contact with the bush by means of a cam, which latter also works
on the valve spindle & the position of which is regulated by the governors, thereby
releasing the lever from contact with the bush sooner or later as the case may be, the
valve being closed by means of a dash pot and rod secured to the bush in the ordinary
way.
RHODES & CRITCHLEY,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in the Trip Motion for Corliss Valves of Steam
Engines.
We, GEORGE GRAY RHODES, of the firm of Rhodes & Critchley, of 27 Kirkgate,
Bradford, in the County of York, Consulting Engineer, and FREDERICK WILLIAM
BYWATER, of the firm of Bywater & Nephew, of Birstal Foundry, Birstal, aforesaid,
Engineer, 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 :-
This invention relates to improved mechanism for the trip motion of Corliss valves
of steam and other engines, and has for its object the arrangement of the whole of
the apparatus on the axis of the valve spindle.
In order to explain our invention reference must be given to the accompanying
sheets of drawings, in which Fig. 1 represents the front view of our improved trip
motion, Fig. 2 a plan, Fig. 3 an end view with the pawl or lever F removed, and the
disc D and valve box bonnet in section, and Fig. 4 a plan of Fig. 3. In all the
figures like letters denote like parts.
The valve spindle marked A of a Corliss valve of a steam engine, passes through
the front bonnet B of the valve box, the bonnet B being cast with a projection or
guide through which the valve spindle A passes, and upon this guide C we mount
an oscillating disc or plate D, which is provided with pins E and E' securely fixed
thereto by means of nuts at the back side of the disc. On to the pin E we pivot the
lever or pawl F, and on to the pin E we attach the rod G, which is connected to a
wrist plate, and by the movement of the wrist plate causes the disc D to oscillate
between the points a and b as shown by the dotted lines in Fig. 1. At the front side
of the disc D, we secure to the valve spindle A a forged steel bush H, by means of a
key K, the bush H being fitted with a projecting steel die H¹ by means of counter-
sunk screws, and we also forge solid with the bush the levers L to which we secure
the pin L, and attach to the latter the rod M in connection with a dash pot. Beyond
the bush A we mount on the valve spindle A a cam N and lever N¹, to which we fix
a pin P, the whole working loose on the valve spindle, and is for the purpose of
tripping the pawl F, the attachment from the governors of the engine being fixed to
the pin P. We secure the cam N by means of a collar O and safety pin, and also
secure the pawl F, rod G, and connection from governors to pin P in a similar
manner, and construct all the working parts of steel case hardened. The end of the
valve spindle we finish off square for the purpose of attaching a handle for actuating
the valve in starting the engine.
The various moving parts are shown in the drawings in mid position, and when the
pin E is at the point a or the commencement of the stroke, the pins E and L' are at
a and a³, (the traverse of which is shown by the dotted lines a¹ and b¹ and a² and b
respectively) then the pawl F is in contact with the bush H and engages with the

page_text: projecting steel die H', and as the rod G causes the disc D to travel from a to b;
the pawl F draws the bush H in the same direction, thus opening the valve, the same
remaining open until the pawl F is lifted out of contact with the bush H and die H¹
by the cam N as shown in Fig. 1, when the valve is closed in the usual way by the
action of a dash pot acting through the rod M, the pawl F having a regular traverse
from a to b¹.
The position of the cam N relative to the pawl F is regulated by the governors,
the lever N¹ having a traverse from c to d, and the nearer it is drawn by the lift of
the governors to the point d, the earlier is the pawl F lifted out of contact with the
die of the bush H, and therefore the earlier is the valve closed, the cam N so regu-
lating the contact of the pawl F with the die H¹ that the cut off of the steam to the
cylinder can be varied by the governors from nil up to seven-eights of the stroke of
the engine.
The pawl F is fitted with a spring recoil box R and steel die S, the pin E having
a flat side for the same. This is shown in Fig. 1 and is for the purpose of keeping
the pawl F to its work, the pressure upon the pin E causing the pawl F to never fail
in engaging with the die H¹, and in order to deaden the sound caused by the pawl F
dropping onto the bush H, we fix a leather pad T let into the bush, and secured by
screws, upon which the pawl drops.
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;
The disc D oscillating on the valve spindle guide C, the latter being a projection
from the valve box bonnet B, arranged substantially in the manner as shown and
described.
The pawl F engaging with the steel die H¹ of the bush H, the pawl F being lifted
or moved out of contact with the die by means of a cam N, the whole being arranged
and working on the axis of the valve spindle A, substantially in the manner as shown
and described, and for the purpose herein set forth.
Dated this 31st day of January 1889.