IMPROVEMENTS IN DIRECT ACTING STEAM ENGINES
Year: 1885

page_text: We SAMUEL GRAHAM BROWNE Engineer and WILLIAM BOBY Engineer both of
No 11 Queen Victoria Street London in the County of Middlesex do hereby declare
the nature of our invention for IMPROVEMENTS IN DIRECT ACTING STEAM ENGINES
to be as follows:-
:-
Our Invention relates to Improvements in the valve gear and parts of Direct
Acting Steam Engines, simple, expansive, or compounded condensing; and more
particularly relates to that class of engine known as Duplex Pumping Engines, in
which the movement of the piston in one engine, controlls the valve gear of the
opposite engine. Provision however is made when desired that either engine can
be used independently, actuating its own gear.
Our invention broadly consists in the use of a special valve gear, and the
arrangement of steam ports and valves. With this in view we use working levers
connected (at one end) to, and moved by, the piston rods in their plane, such levers
passing through trunioned bearings or rocking shafts; and the other terminal ends
used for actuating the valve connecting gear. The working centres of the trunioned
bearings are so placed that the elliptical curve described by the terminal ends of
the working levers (controlling the valves) enables a long piston stroke to be used,
with a short and rapid central valve traverse, and with practically no valve
movement during a portion of the stroke, permitting the exhaust to remain fully
open for a longer period than could be obtained from a radial movement. Suitable
connections are provided so that each working lever actuates the valve of its
opposite cylinder. Where engines are required to work independently, we provide
the trunioned bearings with arms or levers to which the valve rods may be attached
(as well as to the working levers) videlicet, when working in duplex the connecting
rods would be attached to the working levers, and to the trunioned arms when
working independently; the position of the connections being so changed in the
latter case that the valve motion of each engine would be actuated by the movement
of its own piston rod, through its working lever. When engines are designed to
work independently we propose to actuate the main valves of the engines through
the intervention of steam moved pistons, working in supplemental cylinders, as
described in our patent No 465 dated January second 1884. The valve rods
operating the supplemental valves (controlling the reciprocation of the main valves)
being connected to the working levers or to the trunioned arms, the action and

page_text: movement of the valve gear being identical whether working the main valves
directly or the supplemental valves. The steam cylinders are of similar general
construction to those described in the above mentioned patent; the steam ports
entering some distance from the covers. In addition to these we provide other
steam ports leading to the ends and controlled by the main valve. To such other
ports we connect inlets from the cylinders so placed that when the pistons are
nearing the ends of their strokes, steam will be admitted from the then driving end
(through suitable passages in the piston) behind the pistons to cushion them,
provision being made to cut off steam from the then driving ports with the object
of saving steam in the necessary clearance spaces. Where the engines are fitted
with expansion valves we move the same from levers attached to the trunioned
bearings, providing suitable linked or other adjustments for making the traverse
variable.
In compounded condensing engines where steam moved valves are used, we
propose connecting the exhaust of the supplemental cylinders to the respective
ends of the low pressure cylinders, with the object of destroying any vacuum in
the clearance spaces, and providing a cushion for the low pressure pistons.
Double
valves thus ☐ being used for the purpose. The main valves of
the low pressure cylinders may be reciprocated directly from the valve gear or from
the main valves of the high pressure cylinders.
To more fully illustrate our invention we refer to the accompanying diagrams.
Referring to Fig. 1. A. A. A. represents the piston traverse B. B. B. the elliptical
movement of terminal ends of working levers C. C. C the comparative movement
of trunioned levers, D. D. D. radial traverse of expansion levers, all such movements
being operated by working lever F. Fig. 3.
Fig. 2. When working in duplex the connecting rods 1 and 2 are suitably
connected to the working lever (at 1 Fig. 3) and rocking levers 5 and 6 keyed to
the rocking shafts 3 and 4, such shafts actuating cylindrical valves directly or
valves through suitable connections as may be desired. When working
independently the rods 1 and 2 are connected to the trunioned levers (at J Fig. 3)
and respectively to rocking levers 6 and 5 which have been moved to the opposite
ends of the rocking shaft to positions 64 and 54, the position of one rocking lever
being reversed as shown 54 Fig. 1. the trunioned levers thus working the valves of
their own cylinders. When working in duplex it being necessary to have one
valve working in reverse movement, where desireable in manufacture, we may
reverse one set of ports as shewn on Fig. 4, any lost motion required in the valve
gear we provide for by using adjustable cams, links, or by moveable stops as
shewn 7. 7. and 8. 8. 7 and 84. It may be desirable that such stops work in.
suitable cylinders with the object of providing an air cushion, Fig. 4. The main
ports O. Ŏ are shewn reversed, (those in. the opposite cylinders leading direct).
The ports N. N. being covered respectively by the valves K; when about the
centre of its traverse. The valve K is provided with a cut off valve L which has
sufficient lap to cut off steam from the steam inlet M for any required time such
valve being provided with the object of 'cutting off steam just before the reversal
of the valve K from steam to exhaust. We show a cylindrical valve, with the cut
off valve held in position by a spring but in practice may use any suitable class
of valve accomplishing the same function, say for instance a ☐ valve as shewn in
Fig. 5. The inlets P. P from the cylinder connect to the ports N. N. (and are
provided with non return valves R R) admit steam from the driving end of the
cylinder when uncovered by the passages Q. Q. in the traverse, of the piston T
When engines are required to work expansively we provide suitable expansion
valves worked by rods 9. 9. from levers H. H. Fig. 3, such expansion valves being
arranged to have an adjustable width or traverse to vary the cut off, provision being
made for lost motion in the working bridles or connecting rods with the object
of reducing the traverse of the expansion valve, as compared with the movement
of the levers H.
Fig. 6. illustrates an arrangement providing for lost motion to a variable degree

page_text: The connecting rods U are fitted with suitable pistons V (moveable by right and
left hand threads cut on the rod U) such pistons working in suitable cylinders W
in which slots are cut and in which the pins X of pistons V traverse.
The swivel connection Y is suitably connected to the valves. In the cylinders W
we provide two holes Z which on being over-run by the pistons in their traverse
an air cushion is formed between the pistons and cylinder ends. By revolving the
cylinders W the relative positions of the pistons are altered thus providing for any
required lost motion. If desired their positions may be altered by rotating the
right and left handed threads instead of the cylinders, suitable provision being made
for reversing this action.
The diagrams hereunto annexed are simply explanatory of our provisional
specification and not intended as drawings showing the construction and details
of our Engines, which we reserve for our complete specification.

page_text: We SAMUEL GRAHAM BROWNE, Engineer, and WILLIAM BOBY, Engineer, both
of No. 11 Queen Victoria Street, London, in the County of Middlesex, 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:-
Our Invention relates to improvements in the valve gear and parts of Direct
Acting Steam Engines, and more particularly relates to that class of engines known
as Duplex Pumping Engines, which may be arranged for working in duplex only,
or suitably for working each cylinder and pump as an independent engine. When
such engines are required to work either in duplex or independently, the recipro-
cations of the main valves are governed by steam moved pistons controlled by
supplemental valves. When working in duplex the controlling supplemental
valves are actuated each from the piston rod of the opposite engine; when working
independently each is actuated from its own piston rod, suitable connecting gear
being provided. The expansion valves are worked from the piston rods of their
own cylinders. Suitable provision is made for either a fixed or variable amount
of lost motion, as may be required, in the traverse of the main and expansion
valves as shewn, or by other suitable mechanical equivalents.
For a more detailed description of our invention we refer to the accompanying
drawings of which :-
=
Sheet 1 shews a duplex engine suitable for duplex working only. Fig. 1 shews
a section through cylinder at A A. Fig. 2 is a plan of engine. Fig. 3 is a plan of
valve shewing lap beyond the edges of the main ports, but no lap in relation to
the secondary ports. Fig. 4 shews arrangement of ports in the main piston and in
the walls of the cylinder.
Sheet 2, Figs. 5 & 6 shew an elevation and plan of a duplex engine which can
be worked as two independent engines when required. Fig. 7 is a section through
valve chest. Fig. 8 is a section through the main valve chest of a duplex engine
suitable for duplex working only, the valves being of cylindrical form and provided
with a cut off valve preventing the admission of steam into the valve chest during
a portion of the movement of the valve. Fig. 9 is an arrangement for providing
variable lost motion.
Sheet 3. Fig. 10 is a plan of a duplex engine suitable for duplex working only.
Fig. 11 is a section at E E of the main slide h¹ which is arranged to give a motion
to the piston in the reverse direction to that of the movement of the valve itself.
Fig. 12 is an arrangement of a cylindrical valve giving a similar reverse motion to
a supplemental piston, the exhausts from this valve being connected respectively to
the ends of the low pressure cylinder of a compound condensing engine, thereby
providing a small amount of steam at the end of the stroke of the engine enabling
a cushion to be formed in the low pressure cylinder. Fig. 13 is an arrangement
for supplementing the cushion at the end of the low pressure cylinders when
desirable, steam being supplied from the steam jacket of cylinder or from any other

page_text: suitable source and admitted to the cylinder through the valve X when it is
pushed from its seat by the contact of the piston; the volute spring Z returning
it to its seat as the piston moves on its return stroke.
Referring to Sheet 1, the working levers c. c are connected at their lower ends to
the piston rods a¹ through guide pieces or crossheads b, their upper ends passing
through trunnioned bearings d d and connected to linked rods e. e which in their
turn actuate the valve rods and links g g, g¹ g¹ through rocking shafts ff. The
reciprocations of the piston rods a¹ a¹ transmit through this gearing the required
motion to the valves ǹ h. The expansion valves i are reciprocated by the rods J J
which are attached to arms j. j on the trunnioned bearings d'd; thus both the main
and expansion valves are worked by the reciprocations of the pistons a a; a fixed
amount of lost motion is here shewn in the case of both the main and expansion
valves. The main valve h controls the admission of steam both to the main
ports K K and the secondary ports L L leading to the ends of the cylinders, some
amount of lap is provided by the valves where covering the main ports, but none
where they cover the secondary ports, the object being to start the engine slowly
by means of the small ports, yet to avoid having a dead centre resulting from the
lap over the main ports; Fig. 3 is a sectional plan shewing clearly the relations of
the edges of the valve to those of the respective ports. Fig. 10 Sheet 3 shews
another arrangement for connecting the working levers c c to the slide valves h¹ h³
without employing the rocking shafts f. f¹, the cross levers få få taking their
places. To enable one slide valve to give the piston controlled by it a direction of
motion contrary to its own, we may employ the form shewn at Fig. 11 in which k
is the port through which steam is admitted to drive the piston, it is however
shewn as being just cut off by the expansion valve i; or we may employ ports
crossed as shewn in Fig. 8 Sheet 2.
In the arrangement shewn in Fig. 7 Sheet 2 the movement of the supplemental
valve P is similar to the movement of the valves shewn in Fig. 8, the main valve y
being moved by the piston Q. When working in duplex the valve rod F actuates
the supplemental valve in cylinder R through the rocking shaft S and the valve
rod F actuates the supplemental valve in cylinder R¹ through the rocking shaft S¹.
The connecting levers M M¹ are moveable on the rocking shafts S S¹ so that when
the engines are required to work separately the lever Mis moved on the rocking
shaft S and connected to the valve rod F1 and the lever M¹ to the valve rod F.
The valve in cylinder R¹ acting upon crossed ports it becomes necessary in
independent working to reverse the action of these crossed ports, which may be
effected by disconnecting the lost motion cylinder U from the lever M¹, turning the
lever M so that it points upwards, and connecting the joint p¹ on the lost motion
cylinder U to it. The valve rods F F¹ are disconnected from the ends of the
working levers c. c and attached to the arms of the trunnioned bearings at T T¹
enabling each cylinder to give motion to its own slide valve. As the supplemental
valves P are only required to move when in independent gear, during a short.
period near the end of the stroke of the main piston, sufficient lost motion is
given them by adjusting the two pistons OO to the positions shewn on Fig. 9.
When working the engines without expansion in duplex gear, the two pistons 00
can be adjusted by means of the right and left hand threads F2 F3 and the band
wheels F to give no lost motion, or as little as may be required; similarly when
working the engines expansively in duplex the pistons, OO can be adjusted to
give the desired amount of lost motion to prevent one piston from overtaking the
0 other before the completion of its stroke. The ends of the cylinder U form
dashpots to prevent shock in striking the pistons OO. The lost motion may be
obtained by adjustable cams and roller as described in our patent No. 465 of the
second of January 1884, or by any other mechanical equivalent.
The pistons a a are provided with ports N N, Fig. 4 Sheet 1, communicating
5 when the pistons near the ends of their strokes with passages n n, in which a non-
return valve n¹ is placed. When the piston a in its traverse has just cut off the
port K (Fig. 1) then in exhaust, steam is admitted from the driving side through

page_text: the said ports N n to the exhaust side of the piston, which in completing its traverse
cuts off the connection between the ports Nn, imprisoning the steam securely even
should the small valve n¹ fail to act.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is;
1st. A. Direct Acting Duplex Engine constructed combined or arranged sub-
stantially as herein described and shewn in the accompanying drawings.
2nd. In Direct Acting Duplex Engines, the use of a lever connected to the
piston rod at one end and working in its plane, the other end passing through a
trunnioned bearing and actuating the main or supplemental valve in the manner
set forth.
3rd. The arrangement of gear as shewn and described by which the engines may
be worked in duplex, or each worked as an independent engine.
4th. In Direct Acting Engines working expansively, and in which the movement
of the main valve is obtained by the use of a lever connected to the piston rod at
one end and working in its plane, the other end passing through a trunnioned
bearing, actuating the expansion valve by a connection fixed to, or in one piece
with the trunnioned bearing.
5th. In Direct Acting Duplex Engines in which the movement of the main valve
is obtained by the use of a lever connected to the piston rod at one end and
working in its plane, the other end passing through a trunnioned bearing, actuating
the main valves by a connection fixed to or in one piece with the trunnioned
bearing.
6th. In Direct Acting Engines, the arrangement for a variable lost motion as
shown in Fig. 9 Sheet 2, either for duplex or simple working.
7th. The use of the ports N in the main piston, in combination with the passages n
and valve n¹ for the purpose set forth.
8th. In Compounded Condensing Direct Acting Engines the cushioning arrange-
ment herein before described and shown Fig: 12 of the Drawings.
By or oury 1000.
For the Applicants,
W. E. GEDGE,
Agent.