Improvements in the Valve Gear of Engines.
Year: 1894

page_text: Date of Application, 2nd Aug., 1894
Complete Specification Left, 1st May, 1895-Accepted, 1st June, 1895
Improvements in the Valve Gear of Engines.
I, JAMES RUSSELL HOPPER, of No. 1 Lodging House Hopper Danilov
Shipock Street Moscow in the Empire of Russia do hereby declare the nature of
this invention to be as follows: :―
This invention relates to the valve motion of steam engines of the Corliss type
and provides means whereby a single valve at each end of the cylinder may be
made to give an equally good steam distribution to that obtained by separate inlet
and exhaust valves at each end of the cylinder the cut off being controlled by a
suitable form of trip gear for high pressure cylinders and slow running engines and
by a suitable form of link motion for the intermediate and low pressure cylinders
of compound or multiexpansion engines and for quick running engines but in the
latter case the steam distribution is equally good to that obtained by separate inlet
and exhaust valves only within the limits of cut off usually employed in inter-
mediate and low pressure cylinders.
Figure 1 is a side elevation and Figure 2 an end elevation of the arrangement
with trip gear, and Figure 3 is a section of the valves and passages. The crank A
keyed on the spindle of the Corliss valve has pivoted on its crank pin B a double
ended lever C having the pin D at its upper end connected by the rod E to the
pin F in the wrist plate G and the pin H at its lower end connected by the rod K
to any suitable form of automatic trip gear L actuated in the ordinary manner by
an eccentric or other positive motion and controlled by the ordinary automatic
governor or band adjustment and having a spring or steam buffer or cushioning
cylinder M which causes the lower end of lever C when released by the trip gear
to return to a position in which the centre of the pin H coincides with the centre
of the Corliss valve spindle. The wrist plate or lever G is actuated in the ordinary
manner by an eccentric or other positive motion giving the driving pin O an equal
reciprocating motion on each side of the fuleran of the wrist plate or lever. The
position of the pin F is chosen so that it transforms the equal motion of pin O
into an unequal reciprocating motion of the pin D and upper end of the lever C.
When steam requires to be exhausted from the cylinder of the steam engine the
trip gear being released and the pin H being held by the spring or steam buffer as
above described the lever C and crank A act as a single lever and the pin D
receiving motion in the direction of the wrist plate or the side on which pin F
imparts to it the longer travel of the unequal motion and gives the Corliss valve
the required opening for exhaust which takes place through the body of the valve.
When steam requires to be admitted to the cylinder the trip gear comes into
action and by moving the pin H of the lever C in a direction away from the wrist
plate causes the pin B and crank A to nove in the same direction and gives the
Corliss valve the required opening for admission which takes place over the
outside edge of the valve. At the same time the pin D receives motion in
the same direction from the pin F which on this side imparts to it a short travel.
This motion assists in opening the Corliss valve giving a larger opening for
admission at the beginning of the steam stroke. The reduced motion of the pin D
during the steam stroke admits of a corresponding reduction of the outside lap of
the valve and of the travel of the trip gear. The trip gear controls the opening
and closing of the valve for admission and variable cut off in the same manner as
if applied to a separate inlet valve and both exhaust and trip gear eccentrics have
the angular advance of the crank usual in cylinders of the four valve type.

page_text: Figure 4 is a side elevation and Figure 5 an end elevation of the arrangement
with a link motion and Figure 6 is a section of the valves and passages. In this
arrangement the crank A keyed on the spindle of the Corliss valve has pivoted on
its crank pin B one end of a lever Ċ which has at its other end the pin D
connected by the rod E to the pin F in the wrist plate or lever G. The lever C
also has the pin H at a suitable point between the pins B and D connected by the
rod K to the pin L in the wrist plate M. The wrist plate G is actuated in the
ordinary manner by an eccentric or other positive motion through the rod N and
the rocking lever O which gives the pin Pan equal reciprocating motion on each
side of its central position in mid travel. The position of the pin F is chosen so
that it transforms the equal motion of the pin P into a motion of the pin D and
the upper end of the lever C which is longer when moving on the side of mid
travel towards the wrist plate and shorter when moving on the opposite side of
mid travel. The wrist plate or lever M is actuated also by an eccentric or other
positive motion through the rod R block and pin S and slotted link Tone end of
which is pivotted on the pin U of the rocking lever O which gives the pin W an
equal reciprocating motion on each side of its central position in mid travel.
The position of the pin L is chosen so that it transforms the equal motion of the
pin W into a motion of the pin H and the middle part of the lever C similar to
that produced by the pin F on the pin D. When the block and pin S are at the
end of the slot nearest to the pin U the two wrist plates move approximately
together and in the same direction. When the pins P and W are moving on the
side of mid travel away from the valve the pin imparts to the pin D the longer
travel of the unequal motion and the lever C through the pin H as a fulcrum moves
the pin B and crank A opening the valve for exhausting steam from the cylinder,
which takes place through the body of the valve. The pin L at the same time
imparts to the pin H the shorter travel of the unequal motion which acts in the
same direction and assists in opening the valve. When the pins P and W are
moving on the side of mid travel towards the valve, the pin Limparts to the pin H
the longer travel of the unequal motion and the lever through the pin D as a
fulcrum moves the pin B and crank A opening the valve for admission of steam
to the cylinder which takes place over the outside edge of the valve. The pin F
at the same time imparts to the pin D the shorter travel of the unequal motion
which acts in the same direction and assists in opening the valve. The above
position of the block and piu S is for the latest point of cut off. To vary the
point of cut off the block and pin S may be raised or lowered in the slot by an
automatic governor or hand adjustment which will vary the cut off in the ordinary
manner of a link motion the eccentric connected with the link T having the
angular advance usually given to the eccentric for backward gear in reversing link
motions. On account of the reduced travel of the pin H during the exhaust stroke
the travel of the valve is very little shortened by the action of the link T and the
valve both opens and closes the exhaust much later in the stroke than it would if
worked by link motion only. The reduced travel of the pin D during the steam
stroke gives a larger opening of port for a given range of cut off.
Dated this 1st day of August 1894.
F
COMPLETE SPECIFICATION.
Improvements in the Valve Gear of Engines.
J, JAMES RUSSELL HOPPER, of No. 1 Lodging House, Hopper Damlor,
Shipock Street, Moscow, in the Empire of Russia, do hereby declare the nature of 5
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 the valve motion of steam engines of the Corliss type

page_text: and provides means whereby a single valve at each end of the cylinder may be
made to give an equally good steam distribution to that obtained by separate iulet
and exhaust valves at each end of the cylinder the cut-off being controlled by a
suitable form of trip gear for high pressure cylinders and slow running engines
and by a suitable form of link motion for the intermediate and low pressure
cylinders of compound or multi-expansion engines and for quick running engines
but in the latter case the steam distribution is equally good to that obtained by
separate inlet and exhaust valves only within the limits of cut off usually employed
in intermediate and low pressure cylinders.
The drawings which I will now refer to are those left with the Provisional
Specification.
Figure 1 is a side elevation and Figure 2 an end elevation of the arrangement
with trip gear, and Figure 3 is a section of the valves and passages.
The crank A keyed on the spindle of the Corliss valve has pivotted on its
crank piu B a double ended lever C having the pin D at its upper end connected
by the rod E to the pin F in the wrist plate G and the pin H at its lower end
connected by the rod K to any suitable form of automatic trip gear 1. actuated in
the ordinary manner by an eccentric or other positive motion and controlled by
the ordinary automatic governor or hand adjustment and having a spring or steam
buffer or cushioning cylinder M which causes the lower end of lever C when
released by the trip gear to return to a position in which the centre of the pin H
coincides with the centre of the Corliss valve spindle. The wristplate or lever G
is actuated in the ordinary manner by an eccentric or other positive motion giving
the driving pin O an equal reciprocating motion on each side of the fulcrum of the
wrist plate or lever. The position of the pin F is chosen so that it transforms
the equal motion of pin into an unequal reciprocating motion of the pin D
and upper end of the lever C. When steam requires to be exhausted from the
cylinder of the steam engine the trip gear being released and the pin H being
held by the spring or steam buffer as above described the lever C and crank A
act as a single lever and the pin D receiving motion in the direction of the
wrist plate or the side on which pin F imparts to it the longer travel of the
unequal motion and gives the Corliss valve the required opening for exhaust
which takes place through the body of the valve. When steam requires to be
admitted to the cylinder the trip gear comes into action and by moving the
pin H of the lever C in a direction away from the wrist plate causes the pin B
and crank A to move in the same direction and gives the Corliss valve the
required opening for admission which takes place over the outside edge of the
valve. At the same time the pin D receives motion in the same direction from
the pin which on this side imparts to it a short travel. This motion assists in
opening the Corliss valve giving a larger opening for admission at the beginning
of the steam stroke. The reduced motion of the pin D during the steam stroke
admits of a corresponding reduction of the outside lap of the valve and of the
travel of the trip gear. The trip gear controls the opening and closing of the
valve for admission and variable cut-off in the same manner as if applied to a
separate inlet valve and both exhaust and trip gear eccentrics have the angular
advance of the crank usual in cylinders of the four valve type.
Figure 4 is a side elevation and Figure 5 an end elevation of the arrangement
with a link motion and Figure 6 is a section of the valves and passages.
In this arrangement the crank A keyed on the spindle of the Corliss valve has
pivotted on its crank pin B one end of a lever C, which has at its other end the
pin D connected by the rod E to the pin F in the wrist plate or lever G. The
lever C also has the pin H at a suitable point between the pins B and D connected
by the rod K to the pin L in the wrist plate M. The wrist plate G is actuated
in the ordinary manner by an eccentric or other positive motion through the rod N
and the rocking lever O which gives the pin P an equal reciprocating motion on
each side of its central position in mid travel. The position of the pin F is chosen
so that it transforms the equal motion of the pin P into a motion of the pin D and

page_text: the upper end of the lever C which is longer when moving on the side of mid
travel towards the wrist plate and shorter when moving on the opposite side of
mid travel. The wrist plate or lever M is actuated also by an eccentric or other
positive motion through the rod R block and pin S and slotted link T one end of
which is pivotted on the pin U of the rocking lever O which gives the pin W an
equal reciprocating motion on each side of its central position in mid travel. The
position of the pin L is chosen so that it transforms the equal motion of the pin W
into a motion of the pin H and the middle part of the lever C. similar to that
produced by the pin Fon the pin D.
When the block and pin S are at the end of the slot nearest to the pin U the
two wrist plates move approximately together and in the same direction.
When the pins P and W are moving on the side of mid travel away from the
valve the pin F imparts to the pin D the longer travel of the unequal motion and
the lever C through the pin H as a fulcrum moves the pin B and crank A opening
the valve for exhausting steam from the cylinder, which takes place through the
body of the valve. The pin L at the same time imparts to the pin H the shorter
travel of the unequal motion which acts in the same direction and assists in
opening the valve.
When the pins P and W are moving on the side of mid travel
towards the valve, the pin L'imparts to the pin H the longer travel of the
unequal motion and the lever C through the pin D as a fulcrum moves the pin B
and crank A opening the valve for admission of steam to the cylinder which takes
place over the outside edge of the valve. The pin Fat the same time imparts to
the pin D the shorter travel of the unequal motion which acts in the same direction
and assists in opening the valve. The above position of the block and pin S is for
the latest point of cut-off. To vary the point of cut-off the block and pin S may
be raised or lowered in the slot by an automatic governor or hand adjustment
which will vary the cut-off in the ordinary manner of a link motion the eccentric
connected with the link T having the angular advance usually given to the
cccentric for backward gear in reversing link motions. On account of the reduced
travel of the pin H during the exhaust stroke the travel of the valve is very little
shortened by the action of the link T and the valve both opens and closes the
exhaust much later in the stroke than it would if worked by link motion only.
The reduced travel of the pin D during the steam stroke gives a larger opening
of port for a given range of cut-off.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. Valve gear substantially as herein described.
2. Valve gear in which the valve receives its movement substantially as described
through a lever or part C connected with the valve at B and also connected at
points D and H with two rods E and K; such rods acting alternately the one
serving as a fulcrum whilst the valve is mainly or entirely moved by the other and
vice versa.
3. Valve gear in which the valve receives its movement substantially as described
through a lever or part C and rods E and K acting alternately as above stated
and in which one of the said rods receives a variable movement either by trip
gear or link motion.
4. The combination, substantially as described of the valve, the lever or part C,
the rods E and K and the wrist plates or levers from which the rods E and K
derive their movement.
Dated this 30th day of April 1895.
CARPMAEL & Co.,
Agents for the Applicant.