ements in Valve Gear for Steam and other Motive Power Engines.
Year: 1892

page_text: UBATA
Application, 12th Apr., 1802
Complete Specification Left, 11th Jan
cation, 12th Apr., 1892
Complete Specification Left, 11th Jan., 1893-4
PROVISIO
FICATION.
Feb., 1893
ements in Valve Gear for Steam and other Motive Power
Engines.
I, JAMES LUMB of Perseverance Engine Works, Elland in the County of
York, Engineer, do hereby declare the nature of my said invention to be as
follows:-
This invention relates to improvements in valve gear for steam and other motive-
power engines, and is especially designed and arranged for operating one or more
cut-off valves mounted on a valve spindle and working in conjunction with what are
well known as slide valves. The cut-off valve spindle is fitted with a sliding cross-
head, the latter being fitted with either a die or with a notch, with or in which
operates a die or a notch on or in a rod, arm, or lever pivoted to a lever actuated
by an eccentric and rod or other equivalents to give a reciprocating motion to the
same to move the valve spindle and valve or valves in either direction for the
admission of steam or other fluid or gas forming the driving medium. To
the sliding crosshead of the cut-off valve spindle are pivoted toe or other levers
to operate on the pivoted rod, arm, or lever as the valve spindle is slid in either
direction, by which the same is released to allow of the said spindle and valve or
valves being shot back to effect the cut-off by means of a "dash-pot" provided
with piston and springs, or by any suitable springs or other equivalents. The
dash-pot" and other mechanism may be provided with any suitable air or other
cushion with means to regulate the strength of same. To the upper end of each
toe or other lever, employed for releasing the pivoted rod, arm, or lever from the
sliding crosshead of the valve spindle, is attached a rod which couples to a double
lever on a fixed centre on which is mounted a lever for coupling to the main or
other governor, and by which the cut-off is automatically regulated according to
the load to be driven. The levers and the rods connecting the same with the
toe or other levers are provided with means to allow of adjustment according to
the requirements of the cut-off valves. This invention is equally applicable for
operating cut-off slide valves whether working in a horizontal, vertical, or other
position, in which case levers and other apparatus are employed for coupling the
same and effecting the necessary motions.
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Suitable fixings, slides, and other bearings are provided according to the class
of engine this invention may be applicable.
EDMUND CHADWICK,
Agent.
COMPLETE SPECIFICATION.
Improvements in Valve Gear for Steam and other Motive Power
Engines.
I, JAMES LUMB, of Perseverance Engine Works, Elland, in the County of
York, 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 improvements in valve gear for steam and motive power
engines, and is specially designed and arranged for operating one or more cut off
valves mounted on a spindle and working in conjunction with what are well known
The cut off valve spindle is fitted with a sliding crosshead; the
11

page_text: latter being fitted with either a die or with a notch, with or in which operates a
die or a notch on or in a rod, arm or lever, pivoted to a lever actuated by an
eccentric and rod or other equivalents to give a reciprocating motion to the same
to move the valve spindle and valve or valves in either direction, for the admission
of steam or other fluid or gas forming the driving medium. To the sliding cross-
head of the cut off spindle are pivoted, toe or other levers to operate on the pivoted
rod, arm, or lever as the valve spindle is slid in either direction, by which the same
is released to allow of the said spindle and valve or valves, being shot back to effect
the cut off, by means of a "dashpot" provided with pistons and spring, or by any
suitable spring or other equivalents. The "dashpot" and other mechanism may
be provided with any suitable air or other cushion with means to regulate strength
of same.
To the upper end of each toe or other lever, employed for releasing the pivoted
rod, arm, or lever. From the sliding crosshead of the valve spindle is attached a
rod which couples to double lever on a fixed centre, on which is mounted a lever
for coupling to the main or other governor, and by which the cut off is automatically
regulated, according to the load to be driven. The levers and rods connecting the
same with toe or other levers are provided with means to allow of adjustment,
according to the requirements of the cut off valves. This invention is equally
applicable for operating cut off slide valves, whether working in a horizontal,
vertical, or other position, in which case levers and other apparatus are employed
for coupling the same and effecting the necessary motions. Suitable fixings, slides,
and other bearings are provided according to the class of engine this invention
may be applicable.
In order that my invention may be better understood, I now give reference to
the accompaning sheets of drawings.
Fig. 1 is a plan view, Fig. 2 is a side view, Fig. 3 is a section through Z. Z.
and Fig. 4 is a section, showing one arrangement of valves for which this invention
is specially designed.
X is an ordinary slide valve, at the back of which is an intermediate or anchor
plate A 1, at the back of A 1 is a cut off plate Y, coupled to the cut off spindle N
by means of a nut or sleeve B 2. A is a sliding block or crosshead, in which is
fastened, by means of setscrews a steel catch bit B, which stands sufficiently
high above A to form catching edges at each side. This catch bit is made square,
so that it is reversable. In sliding crosshead A are also two rock shafts or pins C
and C 1, on which said pins are fastened toe pieces D and D 1, and on the outer
end C and C 1 are also fastened levers or arms E and E 1. F is a spring box or
dashpot, which may be fitted with loose covers at each end, to be held on with
bolts or setscrews; or one end of the dashpot may be made whole with the
dashpot, but the other end must be fitted with a loose cover. The dashpot F is
fitted up inside with two pistons G and G 1 and a spiral spring H, which said
spring must be sufficiently compressed to push pistons G and G 1 hard against the
ends of dashpot F. Through F I also have a shaft or spindle I which I term
the dashpot spindle; I is formed with a long swell J. I also have on spindle I a
loose bush or sleeve K, held at the proper distance from J by lock nuts L and L 1.
Through lock nut L is fitted a split pin or cottar, for the purpose of finding its
position again, should the nut be removed.
The dashpot ends are bored large enough to receive the swell J and sleeve Kh.
While the pistons G and G 1 are only bored large enough to receive the body of
the spindle. Therefore as the swell J and sleeve K will pass freely through the
ends of the dashpot F, but not through pistons G and G 1, the spindle I whether
pushed or pulled in one direction or the other, will carry one piston with it while
passing through the other thus compressing the spring H, until released, when
spring H will immediately shoot I and cut off plate Y back to their middle
position.
The dashpot F may be mounted either on the same bracket or fixing M, which
forms or carries the slide for crosshead A. or it may be mounted on a seperate

page_text: block A. To spindle I
bracket in a convenient place of position for coupling spindle I up to sliding
To spindle I is coupled the cut off valve spindle N. In any suitable
position, I have a rocking shaft O, which I show carried by brackets or frames P
and P 1, bolted on top of dashpot F.
On this shaft O are fastened a double ended lever Q, and another lever R.
Levers E and E 1 are coupled one to each end of lever QQ, by means of rods S
and S 1. The length of which rods may be regulated or adjusted, by means of
regulating nuts or sleeves T and T 1. Lever R is connected to governors in the
usual way by suitable rods and levers.
which is fixed a steel catch bit V, similar to one in crosshead A. U is coupled to
U is what I term the top catch plate, in
a rod W, which rod W may be worked by an eccentric, camm, or other equivalent,
to give it a reciprocating motion.
Now it is evident that if U be moved backwards or forwards far enongh, one
edge of V will engage with one edge of B, and will push or pull crosshead Å in the
same direction that catch plate U is moving; and in doing this it will compress
spring H in dashpot F, and at the same time move the cut off plate Y. But it will
also be evident that as A is reciprocated the upper ends of levers E and El will
remain stationary according to the position of the governors. Consequently the
toe pieces D and D 1 will oscillate, and the points will alternately rise and fall.
When catch plate U is pushing crosshead A, the rising of the toe piece D, will
by lifting U, release crosshead A, which will be shot back to its middle position by
spring H in dashpot F, but U will go on to the end of its travel; and the catch
bits V and B will next engage at the opposite edge and catch plate U will pull
crosshead A until released by toe piece D1 and will be shot back to its middle
position by spring H in dashpot F. This operation will be repeated each revolution
of the engine. As the governors move up and down through any variation in
speed, caused by any variation in load or steam pressure, the rod W will be moved
up and down as the case might be, thus altering the position of the ends of
levers E and E 1, thereby the point of cut off.
Having now described the nature and particulars of my invention, together
with the manner and means of putting the same into practical operation, I
would have it understood that I do not restrict myself to all the exact forms of
mechanism herein illustrusted, but what I believe to be new, and therefore claim as
my invention as follows:-
Firstly :—In mechanism for producing a variable automatic cut off in connection
with ordinary slide valves. The combination therewith of one crosshead A with
one catch bit B in it, to do duty for both ends of the cylinder.
Secondly-In mechanism for producing a variable automatic cut off in connection
with ordinary slide valves. The combination therewith of one top catch plate U
with one catch bit V in it, to do duty for both ends of the cylinder.
Lastly-The general arrangement, construction, and combination of parts,
substantially as herein set forth and illustrated by drawings, of mechanism for
producing a variable automatic cut off in connection with ordinary slide valves.
1
T
1902
JAMES LUMB.