Improvements in Valve Gear for Steam and other Motive-power Engines.
Year: 1890

page_text: Date of Application, 18th June, 1890-Accepted, 19th July. 1890
COMPLETE SPECIFICATION.
Improvements in Valve Gear for Steam and other Motive-power
Engines.
.1 WALTER MARTIN MUSGRAVE of The Globe Iron Works Bolton Lancashire
Mechanical 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
anu by the following statement :-
The object of my invention is to simplify the valve gear at present used by Messrs.
John Musgrave & Sons Ltd. of Bolton Lancashire.
Referring to the plans accompanying this specification Fig. 1 Sheet 1 gives a
general elevation of valve gear for actuating the steam valves of a Corliss engine.
A rocking motion is communicated to the lever which is fitted with steel wearing
pieces B B of the usual form. Corresponding wearing pieces are fitted to the steam
rods C C. D is the cushioning cylinder containing a spring for closing the valves all
the details being of the usual kind.
The rocking lever A on arriving at the end of its stroke engages with one of the
steam rods & on the return stroke pushes the rod before it thus opening the steam
valve. The point of contact between the wearing pieces upon the steam rod & that
upon the lever A taking a circular path the portion of steam rod E is brought sooner
or later according to the position of the governor into contact with one of the
rollers F F which causes the steam rod to disengage with the lever. The spring in the
cushioning cylinder then closes the valve.
The rollers F F are actuated by the levers J J which are caused to act simulta-
neously by means of suitable levers & connecting rods as shown upon the plans &
described below.
Referring to fig. 1 Sheet 1 the levers J J are attached to the levers K K which are
connected to the lever I by the rods M M. Right & left hand screws are provided
upon the latter for the purpose of adjusting each valve independently.
The lever L is connected to the governor through the lever N & the rod O. The
rod O may also be attached direct to the rods M M. The rod O on being moved by
the governor as the load upon the engine varies & acting through the rods & levers
above described raises or depresses the rollers F F thus altering the point at which the
steam rods are disengaged & the steam valves closed.
Fig. 2 Sheet 2 shows the levers K K coupled to the lever L by means of the
rods M M & the rod P. The point T is furnished with a suitable guide R so that an
equal motion may be transmitted to each of the levers K K. The rod P may instead
of being attached to the lever L be coupled direct to the governor.
Fig. 3 Sheet 2 shows the levers K K coupled together by a single rod M. The rod
is provided with a right & left hand screw which enables the point of cut off to be
equalized at each end of the cylinder-any further adjustment being made by a similar
screw upon the rod O. The rod O is coupled either to one of the levers K at a
suitable radius from its centre or to a separate lever as found convenient.
Figs. 4 & 5 Sheet 2 shows the levers K K coupled directly together by teeth cut
upon their outer extremities. One of the levers is provided with a slot & its position
is detormined by the lever S which is attached to the lever J & is also provided with
a slot.
One of the slots or both of them are placed at an angle with a radial line drawn
through their centres their relative positions may then be altered by moving the
binding screw U thus equalizing the point of cut off.
-
Instead of the rollers FF the levers J J may be formed into cams but I prefer to
use the rollers as the friction of the parts is then reduced.

page_text: Having now particularly described & ascertained the nature of my said inven-
tion & in what manner the same is to be performed 1 declare that what I
claim is :-
In valve gear of the type shown & described
The various arrangements for coupling the levers J J to the governing rod so as to
<secure their simultaneous action or any mere modification of the same.
Dated this 17th day of June 1890.
WALTER MARTIN MUSGRAVE.