Improvements in Steam or other Motive Power Engines.
Year: 1894

page_text: Date of Application, 6th Apr., 1894
Complete Specification Left, 14th Dec., 1894-Accepted, 19th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in Steam or other Motive Power Engines.
I, JAMES DUNLOP of 240 Wallgate Wigan in the County of Lancashire,
Engineer, do hereby declare the nature of this invention to be as follows:-
:—
The object of this invention is to provide a construction or arrangement of
link motion reversing gear of the type known as the "Gooch," by which
independent admission and exhaust valves may be worked, and in which the
adjustment of a single radius rod will alter the various periods of the distribution
in such a manner that for any period of cut off the corresponding periods of
release and compression will be much later than is the case when an ordinary
link motion reversing gear and a single slide valve are employed, the work by
expansion of the steam or other motive power being thereby increased while the
back pressure from compression will at no time be excessive.
The improvements consist of a double-ended lever centred at its intermediate
point on the radius rod or on the admission valve rod or spindle of an ordinary
"Gooch " link motion reversing gear and connected at one end by a link to the
centre point of the expansion or reversing link or to a point on the expansion or
reversing link-hanger within or without the centre point of such expansion or
reversing link the other end being connected by a link to the exhaust valve rod
or spindle.
i
As the motion of the centre point of an expansion or reversing link or of a point
on an expansion or reversing link-hanger is timed opposite that of the crank of an
engine while the motion of a radius rod or of an admission valve rod or spindle is
equivalent to that of an eccentric set with a certain angle of advance that is varied
by each different adjustment of the radius rod so also the motion of the end of the
double ended lever that in the above improvements is connected to the exhaust
valve rod or spindle will be equivalent to that of an eccentric set with a certain
angle of advance that is varied by each different adjustment of the radius rod but,
as will be understood from the disposition of the parts described, this angle of
advance will be less than that of the radius rod equivalent eccentric for all
positions of that rod except the " mid-gear" position when the motions will be
identical.
:
These improvements are applicable also to engines not fitted with a reversing
gear but in which a "Gooch " link motion expansion gear is used, the disposition
of the parts being the same as for a reversing gear.
Any desired type of admission or exhaust valve may be used with these
improvements.
Dated this 5th day of A nril 1894.

page_text: Improvements in Steam or other Motive Power Engines.
I, JAMES DUNLOP of 240 Wallgate, Wigan, in the County of Lancaster,
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:-
The object of this invention is to provide a construction or arrangement of link
motion reversing gear of the type known as the "Gooch," by which independent
admission and exhaust valves may be worked and in which the adjustment of
a single radius rod will alter the various periods of the distribution in such a manner
that for any period of cut off the corresponding periods of release and compression
will be much later than is the case when an ordinary link motion reversing gear and
a single slide valve are employed, the work by expansion of the steam or other
motive power being thereby increased while the back pressure from compression
will at no time be excessive.
One arrangement of this improved link motion reversing gear is shewn in
Figs. 1, 2 and 3 Sheet 1 of the accompanying drawings and represents the
improvements applied to an engine having Corliss valves. The admission valve
levers A, A 1 are linked together by the admission valve connecting rod B, and
actuated from the expansion or reversing link C by the radius rod D which
is adjusted as usual to regulate the various cut offs and the direction of revolution.
Centred at its intermediate point on the admission valve connecting rod B, is
a double ended lever F, termed the supplementary exhaust lever, which is connected
at one end to the exhaust valve levers E. E 1, by the exhaust valve connecting
rods G. G 1, its other end being connected to the centre point of the expansion or
reversing link C, by the rod H termed the supplementary exhaust rod.
By this disposition of the parts it will be understood that as the motion of the
centre point of the expansion or reversing link C is in time with the crank while
the motion of the radius rod D is equivalent to that of an eccentric set with
a certain angle of advance that is varied by each different adjustment of the radius
rod, so also the motion of the end of the supplementary exhaust lever F, where it
is connected to the exhaust valve levers E, E1, will be equivalent to that of
an eccentric set with a certain angle of advance that is varied by each different
adjustment of the radius rod D, but this angle of advance will be less than that of
the radius rod equivalent eccentric for all positions of that rod except the
"mid gear" position when the motion will be identical.
Figs. 1, 2 and 3 Sheet 2 of the accompanying drawings shew these improvements
as applied to an engine having Cornish or double-beat valves. The admission valve
levers A, A1, are linked together by the rod B, which carries the supplementary
exhaust lever F, the connection to the exhaust valve levers E, E 1, being made by
the rods G, G1. The connections to the expansion or reversing link are as
previously described.
Any desired proportion of the relative lengths of the supplementary exhaust
Jever may be used according to the differences in the angles of advance required,
and the supplementary exhaust rod instead of being connected to the centre point
of the expansion or reversing link may be connected to a point on the expansion or
reversing link-hanger, within or without the centre point of such expansion or
reversing link.
These improvements are applicable also to engines not fitted with a reversing
gear but in which a "Gooch "link motion expansion gear is used, the disposition of
the parts being the same as for a reversing gear.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. In a "Gooch " link motion reversing gear for actuating independent admission
and exhaust valves, the use of a double ended lever centred at its intermediate point
on the admission valve connecting rod or its equivalent, and connected at one end
to the centre point of the expansion or reversing link or to a point on the expansion
or reversing link hanger within or without such centre point, the other end being
connected to the exhaust valve connecting rod or its equivalent.
2. In a "Gooch" link motion expansion gear for actuating independent
admission and exhaust valves, the use of a double ended lever centred at its
intermediate point on the admission valve connecting rod or its equivalent, and
connected at one end to the end of the expansion link having a motion in time with
the crank, or to a point on the expansion link hanger within or without such end of
the expansion link, the other end being connected to the exhaust valve connecting
rod or its equivalent.
T: 10th day of Doomber 1901
JAS. DUNLOP.