Improvements in Steam and other Fluid Pressure Engines
Year: 1895

page_text: Date of Application, 1st June, 1895
Complete Specification Left, 1st Apr., 1896-Accepted, 2nd May, 1896
PROVISIONAL SPECIFICATION.
Improvements in Steam and other Fluid Pressure Engines.
I, SAMUEL ROBINSON of 35 Hugon Road, Fulham in the County of Middlesex,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention has reference to steam and other fluid pressure engines and its
chief objects are first to obviate in such engines the effect of back pressure due to
atmospheric resistance and further to obtain in some cases a motion power from
atmospheric pressure in addition to the power obtained from the steam or other
motive fluid and these objects I mainly attain as hereinafter described by putting
both ends of the engine cylinder or opposite ends of two or more cylinders
simultaneously in communication with the exhaust passage that leads or conducts
the expended steam or other motive fluid to the air or to receivers and thence to
the air so that any back pressure from atmospheric resistance acts in reverse
directions and is thereby neutralized; and in some cases the back pressure is more
than counter-balanced so that there is an actual power obtained from the
atmospheric pressure; secondly to provide for utilizing the expended steam or
some of the expended steam from the cylinders in which the high pressure steam
has acted as a retarding power instead of as an impelling power whereby I am
able to apply to a locomotive for example a resistance which is practically a brake
power for stopping the locomotive; thirdly to enable the engine to be readily
converted from a double acting engine to a single acting engine and vice versa or
so as to work with one cylinder inoperative, by altering the relative positions of
the slide valves; fourthly to transmit from the connecting rod which has the
peculiar motion received from the crank a rectilinear motion for operating the
valves and giving them an irregular motion corresponding with the irregular
motion that the pistons receive through the connecting rods from the cranks; and
fifthly a special construction and arrangement of slide valves and mode of working
them as hereinafter described.
My improved engine comprises 3 cylinders of equal capacity and preferably
arranged abreast. For convenience of description I will call these cylinders A, B
and C respectively, C being the middle cylinder. Their pistons are worked by
cranks from the same shaft. The cranks of the pistons of cylinders A and B are
opposite each other or approximately and the crank of the piston of cylinder C is
approximately at right angles to the other two cranks. The engine can be worked
either with cylinder C double acting and cylinders A and B single acting, or
with all three cylinders single acting or with A and B single acting
and C inoperative as may be required the change from one style of working to
another being effected by altering the relative positions of the slide valves as
hereinafter described.
There are 3 slide valves one of which, hereinafter called the main valve, is of
special construction and works on the valve seat; it serves to conduct the steam
or other motive fluid (hereinafter included in the word steam) to and from
cylinders A and B and also to partly conduct the steam to and from cylinder C ;
the other, two valves hereinafter for convenience of description called
respectively. X and Y, are ordinary slide valves and work upon the back or outer
face of, the main valve, one at or near each end of same; the main valve is
ourfoved on both faces.

page_text: There are 6 passages in the valve seat, hereinafter respectively referred to as
passages 1, 2, 34, 5 and 6. Passage 1 leads to the front end of cylinder C that is
to say the end nearer the crank shaft, passage 2 is the exhaust for C cylinder;
passage 3 leads to a permanently open exhaust passage (hereinafter called the air
passage) which communicates between the front ends of cylinders A and B and
also with the final exhaust of C cylinder; passage 4 leads to the back end of
cylinder A; passage 5 to the ends of cylinder B and passage 6 to the back end of
cylinder C.
There are 6 parts in the inner face of the main valve that is to say in the face
that works upon the valve seat just described these ports are hereinafter respectively
referred to as ports 1, 2, 3, 4, 5 and 6. There are four ports hereinafter respectively
referred to as ports 7, 8, 9 and 10 in the back face of the main valve. Ports 7
and 8 act in connection with valve X and ports 9 and 10 in connection with
valve Y. There are 5 passages or chambers in the main valve, hereinafter
respectively referred to as passages a, b, c, d and e. Passage a communicates
between ports 1 and 7; passage between ports 2, 8 and 9; passage e between
ports 3 and 5; passage d between port 4 and the live steam supply for cylinders A
and B; and passage e between ports 6 and 10. The live steam is supplied to the
passage and to the port 4 through two pockets one at each side of the main
valve these pockets being supplied with steam through a port at right angles.
Cylinder C receives its supply of live steam from the valve box the supply to
which is separate from that to the main valve. The live steam in the valve box
presses upon the outer face of the main valve and is balanced by the upper
pressure of the live steam within this valve in the passage d so that the usual great
friction due to the valve being forced hard down upon its seat by the steam
pressure in the valve box is avoided by the two separate steam supplies.
Having explained the construction of the cylinders and valves and the
arrangement of the various ports and passages I will now proceed to describe the
operation, of the engine in the several forms into which it can be converted or in
which it can be worked as has been already herein mentioned.
I will first take the case in which all the three cylinders work as single acting
cylinders. In this case valve X remains in gear and moves independently while
valve Y is thrown out of gear and moves with the main valve. Let us assume
that the working of the engine has reached a point in which the piston of
cylinder A is at the back end of its cylinder, that is to say the end further from
the crank shaft, the piston of B cylinder at the front end of its cylinder and the
piston of cylinder C about the middle of its cylinder, having made about half its
stroke towards the front end inoperative. In this position of the ports A will
receive live steam through passage 4 and its piston will begin to make its stroke,
the piston of B will have just finished its stroke and B will begin to exhaust at the
back end through passage 5, passage c and passage 3 into the air passage which
communicates with the front ends of both cylinders A and B; and the air passage
will also be in communication through passage 2, port 2, passage b, port 1,
passage a, passage 1, port 7, port 8, X valve, also ports 9 and 10, Y valve,
passage 6 and port 6 and chamber e, and therefore with both ends of C cylinder
for the time being. The exhaust steam from B occupies five of the cylinder
chambers, viz. - both ends of cylinder B, the front end of cylinder A and both
ends of cylinder C. As the back pressure at the back end of B is equalized by
the back pressure at the front end of A cylinder, the back pressure on both sides
of C piston acts on the front end of B cylinder piston while it is making its return
stroke. When the piston of cylinder A has made about half its stroke, steam
being cut off at about one-third, the piston of C cylinder has reached the point to
receive live steam at the front end, the valve X begins to open and live steam
enters through passage 1, port 1 and passage a. At this instant only four
chambers communicate with the air, viz. both sides of B, the front of A and the
back of C, and the atmospheric pressure can only effect a balance. When C has
made about half its stroke by live steam and being cut off about one-third,

page_text: A piston will have completed its stroke and B will have reached the position to
receive live steam. Cylinder A will now exhaust from the back end through
port 4 into port 3 and passage c to the front of B and the front of A through the
air
passage, thence to passage 6 ports 9 and 10, passage 6, passage e, port 6 to back
end of C piston. Live steam now enters B at the back end through passage d and
port 4 in the valve to port 5 in the valve seat; and the back pressure at the back
of C is balanced by the back pressure at the front of A piston; as is also the case
with the back pressure at the back of A and the front of B piston. When B has
made about half its stroke with live steam and cut off about one third, piston C has
completed its stroke; X valve is now exhausting both side of piston C through
port 1, passage a, passage I, ports 8 and 7, passages 9, 10, 6 and e and port 6. At
this instant the back pressure is in five chambers, viz. both sides of C piston, the
front of B and both sides of A, the back pressure at the front of B is balanced by
that at the back of cylinder A and the back pressure at both sides of C acts on A
to impel it while returning the last half stroke. B has now finished its stroke by
live steam and expansion, A has reached its starting position and C is at about
half stroke. A revolution is thus completed. There have been two-thirds of
expansion in each cylinder, two-thirds of the time approximately the engine has no
back pressure and one-third of the time the pressure of the air actually assist the
steam pressure.
When it is required to work C cylinder double acting, that is to say to admit
live steam to both ends alternately while cylinders A and B work single acting as
before, the two valves X and Y are inade to move together instead of Y valve
moving with the main valve; X valve will move as before and Y valve will move
independently of either the main valve or X valve. While X is closed Y will
admit steam and vice versa and steam exhausted from the back ends of cylinders A
and B after propelling their positions, will be conducted to the two ends of
cylinder C alternately and the exhaust steam from the two ends of cylinder C
alternately will be conducted to the air passage, whereby the back pressure is
neutralized.
When it is required to work cylinders A and B single acting while cylinder C is
inoperative during both strokes both valves X and Y are thrown out of gear, so
that no live steam can enter C at either end, but the exhaust or expended steam
from A and B alternately will enter the two ends of C simultaneously. The
pressure of the air influences and acts on the pistons on the receding side.
When it is required to utilize the steam, either live steam or the expended steam
as a retarding or brake power a valve situated on the passage called the air passage
is wholly or partly closed so that any steam in the cylinder chambers is locked up,
so to speak, and compression occurs by and from the momentum of the train.
The slide valves X and Y when in gear move a greater distance and at a quicker
speed than the main valve; their movement is due to the movement of the crank
pins and of the piston connecting rod. As the motion of the pistons is irregular
and I intend the valve motion to have an irregular motion corresponding with that
of the pistons so as to prevent or diminish the lap or lead hitherto found necessary;
I dispense with excentrics and convert the motion which the connecting rod
describes and which is given to it by or through the crank motion into a straight
motion similar to that of the piston in all respects. I can effect this as follows:-
I attach to the pin which secure the strap of the other connecting rod and the
connecting rod together a chair or bracket or support for a round spindle or for a
spindle and block or roller. This bracket and roller being fastened to the pins
which secure the straps of the connecting rod naturally move the same as the
connecting rod does. The roller or block is made to work in a slotted link having
a stem which works between guide rollers having spindles resting on bearings in a
frame on the bed plate of the engine. Thus the motion of the connecting rod is
transmitted to the slotted link and the stem of the link being guided as explained
moves the said link in a vertical or straight line, that is to say it rises and falls
with the connecting rod, and the stem of the link has therefore given to it precisely

page_text: the same motion as the piston. In proportion to the stroke of the piston and the
stroke or throw of the main valve the stem of the link transmits this motion to a
bell crank lever on the weigh shaft and thence to the valve spindle. When the
valve is set this motion may be relied upon to move the valve whichever way the
engine is required to work, forward or the reverse. There is a recess in each side
of the main valve to provide for a nut. The spindles of this valve are screw
threaded and I mount thereon a sort of chair or saddle forming a double slide with
an arm thereon which constitutes a fulcrum for levers that work the slide valves X
and Y. These levers transmit the same irregular motion to these two valves, but
this motion is greater than that of the main valve and proportionately quicker,
because these valves have to travel a greater distance than the main valve; the
requisite increased travel is obtained by means of counter levers.
Dated this 1st day of June 1895.
SAMUEL ROBINSON.
Improvements in Steam and other Fluid Pressure Engines.
I, SAMUEL ROBINSON formerly of 35 Hugon Road Fulham in the County of
Middlesex, but now of Hugon House, Station Road, Newport in the County of
Salop Mechanical Engineer, do hereby declare the nature of the said invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
My invention has reference to steam and other fluid pressure engines (herein-
after included in the expression "steam engine") and its chief objects are first to
obviate in such engines the effect of back pressure due to atmospheric resistance,
and further to obtain in some cases a motive power from atmospheric pressure in
addition to the power obtained from the steam or other motive fluid (hereinafter
included in the expression "steam") and these objects I mainly attain as herein-
after described by putting both ends of the engine cylinder or opposite ends of
two or more cylinders simultaneously in communication with the exhaust passage
that leads or conducts the expended steam or other motive fluid to the air or to
receivers and thence to the air, so that any back pressure from atmospheric
resistance acts in reverse directions and is thereby neutralized; and in some cases
owing to the exhaust steam pressure in some of the chambers being in equilibrium
this pressure cannot be affected by the atmospheric pressure, but in the chamber in
which the steam pressure is not in equilibrium the atmospheric pressure can act
and therefore impels the piston on its return stroke, so that the retarding effect of
back pressure is not only obviated but there is an actual power obtained from the
atmospheric pressure; secondly to provide for utilizing the expended steam or
some of the expended steam from the cylinders in which the high pressure steam
has acted as a retarding power instead of as an impelling power, whereby I am
able to apply to a locomotive for example a resistance which is practically a brake
power for stopping the locomotive; thirdly to enable the engine to be readily
converted from a double acting engine to a single acting engine and vice versa or so
as to work with one cylinder inoperative, by altering the relative positions of the
slide valves; fourthly to transmit from the connecting rod which has the peculiar
motion received from the crank, a rectilinear motion for operating the valves and
giving them an irregular motion corresponding with the irregular motion that the
pistons receive through the connecting rods from the cranks; and fifthly a special
construction and arrangement' of slide valves and mode of working them as herein-
after described.
Although this invention is applicable to various types of steam engines, I am of
opinion that the greatest advantage will be gained from its use in connection with

page_text: railway locomotive steam engines. I shall therefore proceed to describe by way of
example the application of my invention to engines having respectively three and
two co-operating steam cylinders, with reference to the accompanying sheets of
illustrative drawings, in which
Figure is a longitudinal section of a three cylinder engine constructed
according to my invention, the three cylinders being of equal capacity;
Figure 2 is a transverse section of the same; Figure 3 (Sheet 3) is a plan of
the same with the valve box and valves removed.
Figures 4, 5 and 6 are diagrams of this engine showing the pistons and cranks
in three several positions.
Figures 7, 8, 9 and 10 are respectively a side elevation, an end elevation and a
plan and an underside view of the main valve of this engine.
Figures 11, 12 and 13 are respectively a side elevation, an end elevation and a
plan of the valve operating gear.
. Figure 14 (Sheet 1) is an elevation showing the general arrangement of a
locomotive constructed with the three cylinder engine.
Figures 15, 16 and 17 are diagrams illustrating a two cylinder engine constructed
according to my invention.
Figures 15 and 15B are views showing the valve seats of the two cylinders
respectively.
Figures 18, 19 and 20 are respectively a longitudinal section, a transverse section
and a plan on a larger scale of the valve of this engine.
Figures 21, 22 and 23 are diagrams illustrating a three cylinder compound engine
constructed according to my invention.
The
My improved three cylinder engine illustrated in Figures 1 to 14, comprises.
three cylinders A B C of equal capacity, preferably arranged abreast, C being the
middle cylinder. Their pistons are worked by cranks from the same shaft.
cranks of the pistons of cylinders A and B are opposite each other or approximately
so, and the crank of the piston of cylinder C is approximately at right angles to
the other two cranks. The engine can be worked either with cylinder C double
acting and cylinders A and B single acting, or with all three cylinders single
acting or with A and B single acting and C inoperative as may be required, the
change from one style of working to another being effected by altering the relative
positions of the slide valves as hereinafter described.
There are three slide valves. X Y Z one of which Z, hereinafter called the
main valve, is of special construction and works on a valve seat formed over the
cylinder C; it serves to conduct the steam to and from cylinders A and B and also
to partly conduct the steam to and from cylinder C. The other two valves X
and Y are ordinary slide valves and work upon the back or outer face of the main
valve, one at or near each end of sanie; the main valve is surfaced on both
faces.
There are six passages 1 2 3 4 5 and 6 in the valve seat (the same effect may
however be produced with five ports only). Passage 1 leads to the front end of
cylinder C that is to say the end nearer the crank shaft; passage 2 is the exhaust
for cylinder C; passage 3 leads to a permanently open exhaust passage K
(hereinafter called the air passage) which communicates between the front ends of
cylinders A and B and also with the final exhaust 2° of cylinder C; passage 4
leads to the back end of cylinder A; passage 5 to the back end of cylinder B';
and passage 6 to the back end of cylinder C.
There are six ports in the under or inner face of the main valve Z, that is to say
in the face that works upon the valve seat just described. These ports are marked
and hereinafter respectively referred to as ports 1 2 3 4 5² and 62. There are
four ports marked and hereinafter respectively referred to as ports 7, 8, 9 and 10
in the top or outer face of the main valve. Ports 7 and 8 are controlled by valve X
and ports 9 and 10 are controlled by valve Y. There are five passages or chambers
in the main valve, marked and hereinafter respectively referred to as passages ab c'd
and e.
Passage a effects communication between ports 12 and 7; passage b between

page_text: ports 2, 8 and 9; passage c between ports 3 and 52; passage d between port 4² and
the live steam supply 4 for cylinders A and B and passage e between ports 6 and 10.
The live steam is supplied from the pipe 4ª to the passage d and to the port 4*
through two pockets Z Z one at each side of the main valve. Cylinder C receives
its supply of live steam from the valve box, the supply to which is separate from
that to the main valve and is effected through the passage 4° (Figure 3). The live
steam in the valve box presses upon the outer face of the main valve Z and is
approximately balanced by the upward pressure of the live steam in the passage d
within this valve so that the usual great friction due to the valve being forced hard
down upon its scat by the steam pressure in the valve box is avoided by the two
separate steam supplies.
Having explained the construction of the cylinders and valves and the arrangement
of the various ports and passages I will now proceed to describe the operation of
the engine in the several forms into which it can be converted or in which it can
be worked as has been already herein mentioned.
I will first take the case in which all the three cylinders work as single acting
cylinders, reference being had more particularly to the diagrammatic Figures 4, 5
and 6. In this case valve X remains in gear and moves independently while valve Y
is thrown out of gear and moves with the main valve Z. Let us assume that the
working of the engine has reached a point in which the piston of cylinder A is at
the back end of its cylinder, that is to say the end further from the crank shaft,
the piston of B cylinder at the front end of its cylinder and the piston of C cylinder
about the middle of its cylinder, having made about half its stroke towards the
front end inoperative. In this position of the parts the back end of cylinder A
will receive live steam through passage 4 and its piston will begin to make its
stroke, the piston of cylinder B will have just finished its stroke and B will begin
to exhaust at the back end through passage 5, passage c and passage 3 into the air
passage K which communicates with the front ends of both cylinders A and B ;
and the air passage will also be in communication through passage 2, port 2,
passage b, port 1, passage a, passage 1, port 7, port 8, valve X; also ports 9 and 10,
valve Y, passage 6 and port 62 and chamber e, and therefore with both ends of
cylinder C for the time being. The exhaust steam from cylinder B occupies five
of the cylinder chambers namely both ends of cylinder B, the front end of cylinder A
and both ends of cylinder C. As the back pressure at the back end of B is
equalized by the back pressure at the front end of A cylinder, the back pressure
on both sides of C piston acts upon the front end of B cylinder piston while it is
making its return stroke. When the piston of cylinder A has made about half its
stroke, steam being cut off at about one third, the piston of C cylinder has reached
the point to receive live steam at the front end, the valve X begins to open and
live steam enters through passage 1, port 12 and passage a. At this instant only
four chambers communicate with the air, namely both sides of B, the front of A
and the back of C, and the atmospheric pressure cannot effect a balance. When C
has made about half.its stroke by live steam and being cut off about one third, the
piston in the cylinder A will have completed its stroke and the piston in the
cylinder B will have reached the position to receive live steam. Cylinder A will
now exhaust from the back end through port 4 into port 3 and passage c to the
front of cylinder B and the front of cylinder A through the air passage, thence to
the passage b, ports 9 and 10, passage 6, passage e, port 6 to back end of the
piston in cylinder C. Live steam now enters cylinder B at the back end through
passage d and port 43 in the valve to port 5 in the valve seat; and the back
pressure at the back of C is balanced by the back pressure at the front of piston A,
as is also the case with the back pressure at the back of A and the front of piston B.
When B has made about half its stroke with live steam and cut off about one third,
piston C has completed its stroke; valve X is now exhausting both sides of piston C
through port 1, passage a, ports 7 and 8, passages 9, 10 passage e and port 6. At
this instant the expended steam is in five chambers viz.-both sides of piston C,
the front of B and both sides of A. The back pressure at the front of B is

page_text: B has
balanced by that at the back of cylinder A, and the back pressure at both sides
of C acts on A to impel it while returning through the last half stroke.
now finished its stroke by live steam and expansion, A has reached its starting
position, and C is at about half stroke, one revolution of the crank shaft having
been thus completed. There have been two thirds of expansion in each cylinder,
two thirds of the time approximately the engine has no back pressure and one
third of the time the pressure of the air actually assists the steam pressure.
When it is required to work cylinder C double acting, that is to say to admit
live steam to both ends alternately while cylinders A and B work single acting as
before, the two valves X and Y are made to move together instead of valve Y
moving with the main valve. Valve X will move as before and valve Y will move
independently of either the main valve or valve X. While X is closed, Y will
admit steam and vice versa, and steam exhausted from the back ends of the
cylinders A and B after propelling their pistons, will be conducted to the two ends
of cylinder C alternately and the exhaust steam from the two ends of cylinder C
alternately will be conducted to the air passage, whereby the back pressure is
neutralized.
When it is required to work cylinders A and B single acting, while cylinder C
is inoperative during both strokes, both valves X and Y are thrown out of gear so
that no live steam can enter C at either end, but the exhaust or expended steam
from A and B alternately will enter the two ends of C simultaneously. The
pressure of the air influences and acts on the pistons on the receding side.
When it is required to utilize the steam, either live steam or the expended steam
as a retarding or brake power, a valve (not shown) situated on the air passage K
is wholly or partly closed so that any steam in the cylinder chambers is locked up,
so to speak, and compression occurs by and from the momentum of the train.
The slide valves X and Y when in gear move a greater distance and at a quicker
speed than the main valve Z; their movement is due to the movement of the crank
pins and of the piston connecting rod. As the motion of the pistons is irregular
and I intend the valve motion to have an irregular motion corresponding with that
of the pistons so as to prevent or diminish the lap or lead hitherto found necessary;
dispense with excentrics and convert the motion which is given to the connecting
rod by the crank motion into a straight motion similar to that of the piston in all
respects. I can effect this as follows:-Referring to Figures 11, 12 and 13 I attach
to the pins 11 which secure the strap of the connecting rod and the connecting rod
together, a bracket or support 12 for a round spindle or for a spindle and block 13.
This bracket and the block 13 being fastened to the pins which secure the strap of
The block 13
the connecting rod move the same as the connecting rod does.
is made to work in a slotted link 14 having a stem 14" which works between guide
rollers 15 having spindles resting on bearings in a frame on the bed plate of the
engine. Thus the motion of the connecting rod is transmitted to the slotted link 14,
and the stem 14" of the link being guided as explained moves the said link in a
vertical or straight line, that is to say, it rises and falls with the connecting rod,
and the stem 14 of the link has therefore given to it precisely the same motion
as the piston. In proportion to the stroke of the piston and the stroke or throw
of the main valve Z the stem 14" of the link transmits this motion to a bell crank
lever 16 on the weigh shaft 17 and thence through rods 18 to the spindles 19, 19 of
the main valve Z. The spindles 19, 19 are screw threaded and I mount thereon
a sort of chair or saddle 20 forming a double slide with an arm 20" thereon carrying
a pin 20° which constitutes a movable fulcrum for levers 21, 22, that work the
spindles 23, 24 of the slide valves X and Y respectively. These levers are
arranged to transmit the same irregular motion to these two valves but this motion
is greater than that of the main valve and proportionately quicker, because these
valves have to travel a greater distance than the main valve; the requisite
increased travel is obtained by means of counter levers. Suitable_mechanism for
this purpose is shown more particularly in Figures 12 and 13. The lever 22 is
prolonged at 22" beyond the movable fulcrum pin 20%, and this prolonged portion 22*

page_text: is arranged to oscillate on or about a pin 25 mounted loosely in or fixed to (as the
case may be) any convenient fixed part of the engine framing. The saddle 20
works on a V slide 26 also fixed to any convenient part of the engine framing. The
valve spindle 24 is guided by means of a slide block 24 working in V guides in
the saddle 20, whilst the valve spindle 23 is similarly guided by means of
a slide block 23ª working in V guides in the slide block 24" of the valve
spindle 23.
In the two cylinder locomotive engine (see Figures 15 to 20) the cranks are at
right angles to each other. The piston of cylinder A in Figure 15 is shown at
the back end of its cylinder, and the crank pin of cylinder A is on the inner
horizontal line, the valve V has commenced to admit live steam from the boiler.
The crank pin of cylinder A will next move towards the top vertical position,
and the crank pin of cylinder C will move towards the inner horizontal position
(see Figure 16). In consequence of this, when the crank of cylinder A has
arrived at the top vertical position (Figure 17) its piston will have moved
about of its stroke, the valve having cut off steam at one-third.
In this position of the pistons, and cranks, the piston of cylinder A is engaged
with live steam and the piston of cylinder C with expanding steam.
The expended steam at the front end of the piston of cylinder A and the
expended steam at the back end of the piston of cylinder C is exhausting.
Therefore the atmospheric pressure on each piston is the same, (instead of as
hitherto each being independent of the other) for a time viz., while the crank pins
of cylinders A and C are moving in opposite directions, which they will do, until
the crank pin of cylinder A. has reached the top vertical position. Now owing
to the position of the exhaust steam also of the pistons and crank pins during the
time the cranks and pistons are moving in opposite directions there can be no
resistance from the air pressure. The steam enclosed by the lap of the valve will
commence to expand. In the meantime, the piston of cylinder C has reached the
back end of its cylinder and the valve commences to admit live steam from the
boiler to the back end of cylinder C, and to uncover the exhaust port to the front
end of cylinder C, and thence to the atmosphere. Thus the front sides of the
pistons of cylinders A and C are both exposed to atmospheric pressure, and while
the piston of cylinder A is making its last half strcke the piston of cylinder C
makes its first half stroke and both pistons are exposed to the atmosphere. As the
air pressure never exceeds 15 pounds per square inch, only 15 pounds per square
inch are lost by resistance as in ordinary cases. Now by allowing the expended
steam in cylinders C and A to be in communication because these pistons and
cranks are independent as regards expended steam, any pressure on the front side
of the pistons, less then the steam effort at the back of the said pistons, (especially
as both are in communication with each other and with the atmosphere) cannot
increase the resistance beyond 15 pounds per square inch on each piston, as in
ordinary cases.
But there is another advantage to be gained by uniting these two volumes of
expended steam while exhausting, viz., to save the large percentage of heat which
is exhausted from the locomotive or other engines, and the great amount of friction
to which the existing valves are subjected.
Owing to the steam pressure from the boiler affecting the rear side of the valve
only, great friction is produced between the valves and their seats. To lessen this
friction, I provide mechanism for conducting the expended steam on the pistons of
cylinders A and C into the atmosphere simultaneously when either of the ends of
the cylinders A and C require to be exhausted. Thus half the back pressure due
to the air and steam pressures coming in contact as in the existing system of engines
is annihilated by my system of putting the expended steam from the two pistons
into, communication with the atmospheric pressure simultaneously. The maximum
throw of the valve in this example is 5 inches, lead of slide valve, lap of slide
valve 1, width of steam port 12. Now, if the valves are set out, and carefully
constructed to, the above dimensions, then notwithstanding that the lead of the

page_text: valve is the cut off does not take place until the crank pin has arrived at the
extreme vertical point, consequently, the piston has travelled 12 of its stroke.
The size of the inlet port is invariable viz. 143. The steam admitted must return
back by the inlet port and then to the exhaust port.
When the steam is allowed to exhaust at about 1 of the stroke, obviously about
70 per cent. of steam energy is exhausted into the air. The chief cause of this is
due to the excess of steam admitted to the engine cylinder. To counteract this
loss I construct the valve V so that it will conduct the steam from the valve box*
first to the valve, then to the inlet port of the cylinder, which enables me to effect
a properly limited supply of steam to the cylinder. Always considering that in
this example the size of the inlet port is invariably 12, the steam admitted must
return back by the inlet port, and then to the exhaust port, and as the steam
from the boiler is in communication with the piston for of the stroke, compression
occurs during of the stroke approximately. Now, provide a port of a given
area or capacity at each end of the valve. This port in each end of the valve
never passes beyond the inlet port of the cylinder.
I have reversed. the position of the foot, or feet, that is to say that part which
provides for the lap, and which controls the expansion, which has hitherto been
situated on the outer part of the slide valve. That is to say, I provide the lap v
on the cup part of the valve. On the outer side, two ports only are seen, which
ports conduct the initial steam to the inlet ports at both ends of the cylinder. On
the inner side or valve face are the bars or feet, which form the lap, and which
control the expansion, their inner edges constitute the exhaust port. The exhaust
steam may be conducted from one cylinder to the other as before described, either
by using a stationary valve in combination with two other valves, or by providing
what is hereinbefore called the air passage, which is in constant communication
with the two cylinders and the atmosphere.
In converting compound engines as at present constructed into compound engines
working on my improved principle I can utilize the present compound cylinders,
and carry out my invention by using the type of valve herein before described
to work on the present valve seats in the present high pressure cylinders. I
I also
require a slide valve similar to that which is used in the present compound cylinders
on this cylinder face but all depends upon the position which the compound valve
and the cranks occupy. I require to exhaust the compound cylinders four times
each revolution, the same as in the ordinary engines not compounded. Referring
to the diagrammatic Figures 21, 22 and 23 the initial steam cylinder cranks are in
the ordinary positions, but the crank pin of cylinder C is opposite the crank pin
of cylinder B, consequently, two of the three cranks and pistous are compelled to
move in an opposite direction thereby securing a constant equilibrity in the cylinders,
which as before explained, answers the purpose of a vacuum in the condensing
engine. The ports on the present valve seat need not be disturbed, the ordinary
excentrics and link motion also need not be removed.
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. A steam engine or other fluid pressure engine in which the steam or other
elastic fluid is caused to act in combination with the pressure of the atmosphere
in such a manner as, without the use of a vacuum, to eliminate and in some cases
to utilize for motive power purposes, the effect of back pressure due to atmospheric
resistance, substantially as described.
2. A steam engine or other fluid pressure engine having three engine cylinders
and arranged and operating on the principle set forth in Claim 1, substantially
as herein before described with reference to Figures 1 to 14 of the accompanying
drawings.
3. A steam engine or other fluid pressure engine having two engine cylinders
arranged and operating on the principle set forth in Claim 1, substantially as

page_text: herein before described with reference to Figures 15 to 20 of the accompanying
drawings.
4. A steam engine or other fluid pressure engine. having 2 or 3 cylinders
constructed and worked in such manner that 2 cylinders are placed in communi-
cation with the exhaust simultaneously whereby half the back pressure due to
atmospheric resistance is obviated and the friction on the valve is considerably
decreased, substantially as described.
5. In a steam engine or other fluid pressure engine the improved valve V. with
inside lap v and with steam supply ports v v² constructed, arranged and operating
substantially as herein before described and for the purpose specified with reference
to Figures 18, 19 and 20 of the accompanying drawings.
6. In a steam or other fluid pressure engine, having three engine cylinders
arranged and operating on the principle set forth in Claim 1, the combination and
arrangement of the three valves X, Y, Z, constructed and operating substantially
as hereinbefore described and for the purpose specified with reference to Figures 7
to 13 of the accompanying drawings.
7. In a steam engine or other fluid pressure engine having one or more engine
cylinders, the construction and arrangement of gear for imparting to the valve or
valves an irregular motion analogous to that of the engine piston or pistons,
substantially as herein before described with reference to Figures 11, 12 and 13 of
the accompanying drawings.
Dated this 1st day of April 1896.
SAMUEL ROBINSON.