IMPROVEMENTS IN MACHINERY FOR RAISING AND FORCING FLUIDS, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO STEAM ENGINES, BLAST ENGINES, EXHAUSTERS, AND OTHER MACHINES
Year: 1863

page_text: LETTERS PATENT to Stephen Holman, of 18, Cannon Street, London, E.C.,
Engineer, for the Invention of "IMPROVEMENTS IN MACHINERY FOR RAISING
AND FORCING FLUIDS, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE
TO STEAM ENGINES, BLAST ENGINES, EXHAUSTERS, AND OTHER MACHINES."
ealed the 26th April 1864, and dated the 31st October 1863.
PROVISIONAL SPECIFICATION left by the said Stephen Holman at the
Office of the Commissioners of Patents, with his Petition, on the 31st
October 1863.
I, STEPHEN HOLMAN, of 18, Cannon Street, London, E.C., in the County
of Middlesex, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MACHINERY FOR RAISING AND FORCING FLUIDS, PARTS OF WHICH
IMPROVEMENTS ARE ALSO APPLICABLE TO STEAM ENGINES, BLAST ENGINES, Ex-
HAUSTERS, AND OTHER MACHINES," to be as follows:-
This Invention relates, firstly, to a novel construction and arrangement of
pump valves and passages, by means of which a simple and efficient pump is
produced. The pump consists of a double open-ended cylinder made in a
continuous line, with a shifting oscillating double-beat valve placed in a
chamber formed midway of the double cylinder; two pistons are fitted to one
piston rod, which rod passes through the chamber and also through the oscillat-
[Price 8d.1

page_text: ing double-beat valve. The pistons may be actuated by any method of pro-
ducing a reciprocating motion. The oscillating valve which works in the
chamber between the two pistons is a delivery valve only, but is common to both
pistons, and is operated upon by each at the same time, being forced by one
and drawn by the other. The double cylinder or double barrell, as more
generally expressed, for pumps may be made in one or more pieces; to make
this more readily understood I will consider it as having two cylinders viz.,
one cylinder on each side of the delivery valve chamber, which delivery valve
serves for both cylinders or both pistons. Openings are formed in the cylinders
in close proximity to the central delivery valve chamber for the admission of
water or other fluid to follow the course of the piston. A suction valve is pro-
vided for each piston, and the pump will work in the following manner:-
Motion is communicated to the pistons simultaneously as either piston recedes
from the centre towards the open end of the cylinder; it draws the double-beat
delivery valve (through which the piston rod passes) up against the seat in the
valve chamber nearest to it, and thus creating a vacuum; the suction valve is
opened, and water or other fluid is admitted to the cylinder in the ordinary
way. At the return stroke of the piston the suction valve is closed, and the
delivery valve is forced from its seat by the water driven by the returning
piston, and at the same time drawn from it by the other piston on the other
side of the central delivery valve chamber by vacuum, and the water or other
fluid is readily discharged; the repetition of this action with every forward
and backward movement of the pistons will effect a copious and continuous
discharge of water or other fluid at the outlet pipe. The traverse or oscillation
of the discharge valve may be regulated as required for the discharge of water,
gas, air, or other fluids, and the delivery valve may be inserted through an
opening made between the suction valves, or through an opening made in any
other convenient part of the chamber. Oscillating suction valves can also be
arranged for this pump, but not to general advantage. I observe here, how-
ever, that the suction valves and the suction valve chambers and passages
may be variously modified without affecting the action and arrangement of the
oscillating double-beat valve and valve chamber between two pistons, as herein
described, and which forms the principal part of this Invention.
.
This Invention relates, secondly, to a novel arrangement of pump valves and
passages, whereby a pump of a very large working capacity is simply & cheaply
constructed. This pump consists of two pairs of barrels or cylinders, as
described in the first part of this Invention, having oscillating double-beat
delivery valves; each double barrel or pair of barrels are attached to a central
suction valve and discharge chamber; this chamber may be made to contain

page_text: two suction valves only, each suction valve to be of sufficient areal capacity to
supply two pistons at once; or it may be made to contain four valves, one for
each piston. When two suction valves only are used a diagonal division is
made in the chamber, so that the upper piston of one pair of barrels and the
lower piston of the other pair may draw simultaneously from one valve; or if
it be desired to make the both piston rods to traverse in the same direction at
once, a mere modification of the suction valve passages will be necessary
without affecting the principle. When four valves are used, the arrangement
of the valves described in the first part of this Invention will be made in
duplicate. In either case, whether two or four suction valves are used, the
chamber, the upper part of which is also an air vessel, is carried up to the
proper height to support a lever, to which the piston rods are attached or
connected by links or connecting rods for the purpose of working the pump;
the facility thus afforded by a central fulcrum for one lever to communicate
motion to four pistons is an important part of this arrangement, because a
double-working capacity is obtained at a comparatively little cost.
This Invention relates, thirdly, to a ready method of adjusting or securing
two pistons on one rod simultaneously. When india-rubber or other flexible
blocks are used for pistons within the cups two metal plates are usually placed
one on each side to keep the parts forming the piston together; the flexible
blocks will expand or spread under pressure. To regulate the pressure on the
two pistons simultaneously, I purpose placing a piece of metal tube the
required length over the rod between the two pistons the thickness of the metal
tube to form the shoulders necessary to keep the inner plates in their proper
position. It will be obvious that by screwing up a nut at either end of the
rod that it will have the effect of drawing the rod through the tube, and the
tube being confined between the two pistons they will be both tightened at
once, and vica versa.
This Invention relates, fourthly, to an adaptation of the oscillating double-
beat valve to steam engines, water engines, blast engines, exhausters, and
other machines, the arrangement of the cylinders and pistons, together with
the central valve chamber, are similar to that described in the first part of this
Invention, but there is this difference in the operation of the pump and the
steam engine, that whereas motion is communicated to the pistons of the pump,
the pistons of the steam engines are the means of communicating motion,
circular openings being made in the sides of the central valve chamber for the
admission of steam to each cylinder and piston alternately; the inner sides of
the said central valve chamber are made true, and the oscillating double-beat
valve is made true on each side. (For pumping and other purposes which require

page_text: a reciprocating action only, all cranks, fly wheels, shafts, and their appurte-
nances may be either used or dispensed with.) The valve may be actuated by
the pistons in the following manner: Steam being admitted to the cylinder it
will act against the piston and force the valve back against the seat in the
chamber nearest the other cylinder, both the pistons will then make their
stroke with the rod passing through the valve, the piston on which the steam
is acting travelling towards the open end of the cylinder, and the other piston
travelling towards the centre until it strikes the valve; the valve being less in
area than the pistons will be readily moved from its seat a sufficient distance
to cover one exhaust port and open another, and the valve may be forced
quite over against the opposite side either by the steam only, or by the help of
a spring between each piston and the valve; the exhaust steam will pass
through ports or openings formed in the oscillating valve, which ports com-
inrunicate with stationary ports or openings arranged corresponding to the
determined traverse of the valve, which is virtually an oscillating slide valve.
The valve in cross section to the line of the piston rod may be either round or
D-shaped; arrangements can also be made for condensing and working the
steam expansively. Water engines can be economically constructed on this
principle, and where a head of water can be obtained may be used as a water
ram, either in combination with a pump, as specified in the first part of this
Invention, or by extending the piston rod at one or both ends, and applying
them as ordinary plunger pumps. A mere modification only is necessary to
adapt the oscillating double-beat valve to blast engines, exhausters, syringes,
fire engines, and other machines.
I have hitherto specified a single oscillating valve only between two pistons;
two valves may be used in the same chamber between the two pistons, if
necessary, with or without springs to assist their action, and valves formed of
other material than metal, such as india-rubber (flexible or otherwise), with
suitable seatings, may be used, or facings of leather or other material may be
put on to the metal valve; and, whenever desirable, a stuffing box can be
readily applied to the valve; exterior means for working and balancing the
valve may also be employed.
I particularly claim the oscillating valve or valves worked in a chamber
(having seatings inside the chamber itself or in the cylinders) between two
pistons, and through which the piston rod passes, in the manner herein set
forth, or any mere modification thereof.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Stephen Holman in the Great Seal Patent Office on the 30th
April 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, STEPHEN
HOLMAN, of 18, Cannon Street, in the City of London, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of October, in the year of our
Lord One thousand eight hundred and sixty-three, in the
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Stephen Holman, Her special licence that I, the said
Stephen Holman, my executors, administrators, and assigns, or such others as
I, the said Stephen Holman, executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE.
MENTS IN MACHINERY FOR RAISING AND FORCING FLUIDS, PART OF WHICH IMPROVE
MENTS 18 ALSO APPLICABLE TO STEAM ENGINES; BLAST ENGINES, EXHAUSTERS, AND
OTHER MACHINES," upon the condition (amongst others) that I, the said Stephen
Holman, my executors or administrators, by an instrument in writing under
or their, on one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Stephen Holman, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
This Invention relates, firstly, to a novel construction and arrangement of
pump valves and water passages, by means of which a simple and efficient
pump is produced. The pump consists of a double open-ended cylinder
made in a continuous line with a shifting or oscillating double-beat valve
working in a chamber formed midway of the double cylinder; two pistons are
secured to one piston rod, which rod passes through the chamber and also

page_text: through the oscillating double-beat valve. The piston may be actuated by
any ordinary method of producing a reciprocating motion. The oscillating
valve which works in the chamber between the two pistons is a delivery valve
only, but is common to both pistons, and is operated upon by each at the same
time, being drawn by one and forced by the other. The double cylinder or
double barrel (as more generally, expressed for pumps) may be made in one
or more pieces, and to make it more readily understood I will consider it as
two cylinders, viz., one cylinder on each side of the delivery valve chamber,
which delivery valve serves for both pistons. Openings are formed in the
cylinders in close proximity to the central delivery valve chamber for
the admission of water or other fluid to follow the course of the piston. A
suction valve is provided for each piston, and the pump will work in the
following manner: -Motion is communicated to the pistons simultaneously
as either piston recedes from the centre towards the open ends of the cylinder;
it draws the double-beat delivery valve (through which the piston rod passes)
up against the seat in the valve chamber nearest to it, and thus creating a
vacuum the suction valve in communication with the receding piston is opened,
and water or other fluid is admitted to the cylinder in the ordinary way.
At the return stroke of the piston the suction valve is closed, and the delivery
valve is forced from its seat by the water driven by the returning piston, and
at the same time drawn from it by the other piston on the other side of the
delivery valve chamber by vacuum, and the water or other fluid
is readily discharged; the repetition of this action with every forward and
backward movement of the pistons will effect a copious and continuous dis-
charge of water or other fluid at the outlet pipe. The traverse or oscillation of
the discharge valve may be regulated as required for the discharge of water,
gas, air, or other fluids, and the delivery valve may be inserted through an
opening between the suction valves, or through an opening made in any other
.convenient part of the chamber. Oscillating suction valves might also be
arranged for the pump, but not to general advantage. I observe here, how-
ever, that the suction valves and the suction valve chambers and passages
may be variously modified without affecting the action and arrangement of the
oscillating double-beat valve and valve chambers between two pistons, as
herein described, and which forms the principal part of this Invention.
This Invention relates, secondly, to a novel arrangement of pump valves
and passages, whereby a pump of a very large working capacity is simply and
cheaply constructed. This pump consists of two pairs of barrels or cylinders,
as described in the first part of this Invention, having oscillating double beat
delivery valves; each double barrel or pair of barrels is attached to a central

page_text: suction valve and discharge chamber; this chamber may be made to contain
two suction valves only, each suction valve to be of sufficient areal capacity to
supply two pistons at once; or it may be made to contain four such suction
valves, one for each piston. When two suction valves only are used a diagonal
division is made in the chamber, so that the upper piston of one pair of barrels
and the lower piston of the other pair may draw simultaneously from one valve;
or if it be desired to make both piston rods to traverse in the same direction
at once, a mere modification of the suction valve passages will be necessary
without affecting the principle. When four valves are used, the arrangement
of the valves described in the first part of this Invention will be in duplicate.
In either case, whether two or four suction valves are used, the chamber,
the upper part of which is also an air vessel, is carried up the proper height to
support a lever, to which the piston rods are attached or connected by links or
connecting rods for the purpose of working the pump; the facility thus afforded
by a central fulcrum for one lever to work the four pistons is an important
part of this arrangement, because a double-working capacity is obtained at a
comparatively little cost.
This Invention relates, thirdly, to a ready method of adjusting or securing
two pistons on one rod simultaneously. When india-rubber or other flexible
blocks are used for pistons within the cups two metal plates are usually placed
one on each side to keep the parts forming the piston together; the flexible
blocks will expand or spread under pressure. To regulate the pressure
on the two pistons simultaneously, I purpose placing a piece of metal tube the
required length over the rod between the two pistons the thickness of the
metal tube to form the shoulders necessary to keep the inner plates in their
proper position. It will be obvious that by screwing up a nut at either end
of the rod that it will have the effect of drawing the rod through the tube,
and the tube being confined between the two pistons they will be both
tightened at once, or by unscrewing the nut they will be both loosened at
once.
This Invention relates, fourthly, to an adaptation of the oscillating double-
beat valve to steam engines, water engines, blast engines, exhausters, and other
machines, the arrangement of the cylinder and piston, together with the
central valve chamber, are similar to that described in the first part of this
Invention, but there is this difference in the operation of the pump and the
steam engine, that whereas motion is communicated to the pistons of the
pump, the pistons of the steam engine are the means of communicating
motion, circular openings being made in the sides of the central valve chamber

page_text: for the admission of steam to each cylinder and piston alternately; the inner
sides of the said central valve chamber are made true, and the oscillating
double-beat valve is made true on each side. For pumping and other pur-
poses which require a reciprocating action only, all cranks, fly wheels, shafts,
and their appurtenances may be either used or dispensed with.
The valves may be actuated by the pistons in the following manner:-Steam
being admitted to the cylinder it will act against the piston and force the valve
back against the seat in the chamber nearest the other cylinder; both the
pistons will then make their stroke with the rod passing through the valve,
the piston on which the steam is acting travelling towards the open end of the
cylinder, and the other piston travelling towards the centre until
it strikes the valve; the valve being less in area than the piston will be readily
moved from its seat a sufficient distance to cover one exhaust port and open
another, and the valve may be forced quite over against the opposite side,
either by the steam only or by the help of a spring between each piston and
the valve; the exhaust steam will pass through ports or openings formed in
the oscillating valve, which ports communicate with stationary ports or open-
ings arranged corresponding to the determined traverse of the valve, which
is virtually an oscillating slide valve. The valve in cross section to the line of
the piston rod may be either round or -shaped; arrangements can also be
made for condensing and working the steam expansively. Water engines can
be economically constructed on this principle, and where a head of water
can be obtained may be used as a water ram, either in combination with a
pump, as specified in the first part of this Invention, or by extending the
piston rod at one or both ends, and applying them as ordinary plunger pumps.
A mere modification only is necessary to adapt the oscillating double-beat
valve to blast engines, exhausters, syringes, fire engines, and other machines.
All cranks, fly wheels, shafts, and their appurtenances may be either used or
dispensed with.
i
I have hitherto specified a single oscillating valve only between two pistons;
two valves may be used in the same chamber between the two pistons, if
necessary, with or without springs to assist their action, and valves formed of
other material than metal such as india-rubber, flexible or otherwise, with
suitable seatings, may be used, or facings of leather or other material may be
put on to the metal valve; and, whenever desirable, a stuffing box can be
readily applied to the valve; exterior means for working and balancing the
valve may also be employed.
In order that this Invention may be fully understood, I will now describe

page_text: the Drawings hereunto annexed, taking first those that contain the new
features claimed; and, secondly, some of the modifications of which the
arrangement is capable.
Fig. 1 shews an elevation of pump A and steam engine B mounted on a
bed plate C, and provided with a sliding bar D, which bar is worked by the
piston rod E by means of the arm F; the bar D is so shaped that by its reci-
procating action it moves alternately the two rollers G secured to lever H,
which lever works a central spindle, having on the inside a short arm or lever
for shifting the oscillating or sliding valve between the pistons (see arm I and
valve K in illustration, Fig. 7), and also a flexible or rigid vertical lever L,
with a regulator ball M; Fig. 2 is a general plan of same; Fig. 3 is a sec-
tional view both of the pump and steam engine, as specified in the first and
fourth parts of this Invention.
.
A, A, is a double-pump barrel with a central valve chamber N; O and R
are two pistons attached to one rod Q, which is turned parallel between the
pistons; P is a central oscillating double-beat valve (bored so as to slide on
the rod Q); S is the tail-piece of the pump, arranged with two inlet passages
T1, T2, and one outlet passage U. The action of the pump will be as follows:-
The valve P is shewn in its proper position in the chamber N when the
pistons are moved in the direction indicated by arrows 1 and 3; thus the
vacuum formed by piston R will cause the fluid to open the valve covering
passage T and enter the cylinder in which it works, at the same time the
fluid will be forced out of the cylinder in which piston O works through
the central valve chamber N, as indicated by arrow 3, and will be ultimately
discharged through the outlet passage U; at the return of stroke the valve P
will shift to the other side of chamber N, and vacuum will then be formed by
piston O, which will open the valve covering passage T¹ to fill the barrel in
which piston O works; at the same time the valve covering passage T will be
closed, and the fluid which had previously followed piston R will now be
forced by it through the chamber N, in a precisely similar manner as indi-
cated by arrow 3, continuing the discharge through the outlet passage U. It
will be obvious that the central valve P serves each piston alternately, and it
is important to note that although the valve P would appear to bear with its
whole weight on rod Q, that practically by the action of the vacuum on one
side, and the pressure of the fluid on the other, the valve is kept up against
the seat on either side of the chamber N, whilst the rod passes through its
centre comparatively free.
An important modification of this pump, whereby a double-working capacity

page_text: is obtained at a comparatively small additional cost, is shewn in Fig. 18.
The number and arrangement of valves are precisely the same as in Fig. 3.
The difference of this pump consists in the simple addition of two water
passages, and making close instead of open ends to the barrels. The arrows
1, 2, and 3 indicate the ingress of fluid to the pump following the course
of pistons O and R through inlet valve T2, which valve must be of suffi-
cient areal capacity to admit the fluid to follow both the pistons O and R at
the same time. The arrows 4, 5, and 6 indicate the course of the fluid in its
discharge from the pump through the central valve chamber N, as described
in Fig. 3. The suction valves T1, T2, open alternately to allow the fluid to
follow either side of pistons O and R as they reciprocate in barrels A, A. The
arrangement of the valves is here shewn on plan; the elevation is the same as
shewn in Fig. 3.
I will now describe the oscillating valve for steam engine purposes as
shewn in Fig. 3, modifications of which are also shewn in Figs. 7, 10,
and 13.
A, B, is a double cylinder with open ends provided with two pistons C
and D affixed to one piston rod E; H is the oscillating or slide valve
shewn in the centre of the chamber I, I, through which rod E passes;
L is the steam induction pipe; M, the exhaust pipe. The valve H in the
position shewn covers both the exhaust ports, which will be readily seen
without reference to Figures. K, K, are circular openings through which
the steam is admitted to each cylinder and piston alternately; 0, 0, are
two springs loose on rod E. The arrow marked 4 indicates the direction
the pistons should move in order to bring the valve H in the position
shewn. The springs 0, 0, should be made to resist the pressure of the
steam on the area of either side of the valve H, and the valve H being of
considerably less area than the pistons C and D, the effect in practice will
be as follows:-
The steam being admitted to cylinder B through opening K, will force
the pistons in the direction indicated by arrow 4, until the spring O on
rod E near piston C reaches the valve H, the spring will then collapse
or shorten, and when shortened to a power equal to moving the valve H,
the valve will be moved to the central position shewn, in which position
the steam will be momentarily in equilibrium, but the power of the spring
near piston C will now be exerted, and the valve H will be readily pushed
past the centre, thus the opening K in cylinder B will be closed by the valve H
fitting closely into it, and the steam will be exhausted from cylinder B through

page_text: the port formed in the valve H, indicated by arrow 5; other ports are formed
at the bottom of the cylinder (communicating with the exhaust port M) and
corresponding with the traverse of the valve H, through which the steam is
exhausted from each piston alternately as now described.
Fig. 4 is a cross section through L, M, of steam engine, giving elevation of
valve H. Fig. 5 shews a cross section at X, Y, of pump, shewing elevation
of valve P.
Fig. 16 is a sectional elevation of a pump as specified in the second part of
this Invention.
A, A, and B, B, are two double barrels; C, D, E, F, are four pistons;
P, P, are two oscillating double-beat delivery valves; T1, T2, are suction
or inlet valves to barrels A, A, and pistons C, D; T3, T4, are suction or
inlet valves to barrels B, B, and pistons E, F; the barrels, pistons, and valves
are simply duplicates of the pump shewn in Fig. 3, placed vertically and
attached to a central valve box or communicating chamber, of which G forms
the inlet to both the upper and lower suction valves; H is the discharge
passage common to the four pistons; all the valves are shewn at rest. When
the pump is moved in the direction indicated by arrows 5 and 6, the pistons C
and F will force the water past valves P, P, through outlet passage H, as
indicated by arrows 7 and 8 (the central valve P in barrel B, B, will be
raised by the fluid forced out by piston F), suction valves T, T³, will at the
same time be opened to allow the fluid to follow pistons D and E, thus the
upper barrel A and the lower barrel B will be discharged by pistons C and F
whilst the lower barrel A and the upper barrel B are being filled by the fluid
following pistons D and E, and the constant repetition of this action will
effect a copious delivery through outlet passage H. This pump can be
arranged with two suction vaives only by causing two pistons to draw the
fluid through one valve simultaneously, similar to those described in Fig. 18.
Fig. 17 is a cross section at I, G, of Fig. 16.
The method of adjusting or tightening and loosening two pistons at one
time, according to the description of the third part of this Invention, will
also be explained by further reference to Fig. 16, viz., when india-rubber
or other flexible material forms the body of the pistons at C, D, E, F, it
is placed between two metal plates, as shewn at M, N; this flexible material is
contained in a cupping of leather or other substance suitable for the exterior
of the piston; a tube V, V, is fitted on the rod S, and turned the right length
to go between the plates M and O of the two pistons C and D, thus forming
a shoulder or stop for each of the said plates M and O. It will be obvious

page_text: that by screwing up the nut R the rod S will be drawn through the tube V,
which will have the effect of compressing and spreading the flexible material
at C and D, thereby causing them to fit the barrel tightly, and by unscrewing
nut R an opposite effect will be produced.
Figs. 7 to 12 inclusive shew a modification of the steam engine and pump
as shewn and described in preceding references to Fig. 3. The central valve K
is here shewn round or piston-shaped; its traverse is determined by the range
of lever I on the inner end, and lever L on the outer end of spindle M. The
steam enters the cylinders B, B, through the upper ports, and exhausts
through the lower ports, as before described; but in this arrangement two
springs are placed in pockets O, O, (see Fig. 10) with rod P passing through
them having screw adjusting nuts on the ends. The springs are confined in
pockets O, O, by caps Q, Q, and are sufficiently strong to resist the pressure
of steam on the area of either side of valve K; for example, assume the
end of valve K to have a superficial area of 10 square inches, steam at 40 lbs.
per inch would require a resistance of 400 lbs., or 200 lbs. for each spring,
but by making outside lever L in Fig. 8 double the length of inside lever I in
Fig. 7, the requisite resisting power of each spring would be 100 lbs.; the
proportions, however, are arbitrary.
A further modification is effected by combining the water passages A, A, (as
shewn in Figs. 10 and 13) with barrels B, B, and closing the ends by means
of hollow flanged covers E, E; a set of valves, viz., two suction valves T¹, T³,
and a central delivery valve P are placed in passages A, A. The action of this
engine will be understood by reference to the Figures, as follows:-When the
pistons C, D, are moved in the direction indicated by arrows 1 and 2, steam
will be acting on face F of piston C, vacuum will be at the same time formed
by piston D, and the fluid will enter through suction valve T3 to follow it, as
indicated by arrow 4; piston C will discharge at the same time through valve
chamber N, as indicated by arrow 3 in Figures 3, 10, and 13. It will be
readily understood that the steam acts only on the surfaces F and G of
pistons C and D, so that the surfaces H and I are free to act as ordinary
pump pistons; this arrangement is best suited for hot liquors.
Fig. 9 is a section through Y, Z, of Fig. 10; Fig. 11, outline plan of same;
Fig. 12, end view of flanged cover E. When valve K is worked by exterior
connections independently of the pistons, rod S will be carried through a stuffing
box at R in cover E.
Fig. 13 gives another example of the variety of modification to which the
movement of valve K may be subjected. In this Illustration, U is a com-

page_text: pensating steam balance which commands valve K through the medium of
lever I; the enlarged ends X1, X2, move steam-tight in the cylinder J, J.
The traverse of this compensating balance, and also of valve K, will be
determined by valves V, V, in the following manner:-Steam being admitted
into either cylinder B, B, it will act on whichever side of valve K is ex-
posed to the cylinder into which the steam is admitted; thus if steam is
admitted into cylinder 62, the effect will be to force valve K in the direction
of the arrow on the piston rod S, the compensating balance U will then be
moved in the opposite direction, as indicated by arrow 5, until it reaches
valve V, which valve on being opened will admit steam from the passage
indicated by arrow 6, and take in just sufficient to act on the area X³ as will
counteract and control the steam acting on the same side of valve K; this
operation will be repeated at each half stroke in a precisely similar manner.
Handles A1, A2, are attached to two cocks which will either admit or exhaust
the steam from valve chambers V, V, at pleasure.
Fig. 15 is a cross section through E¹, E. D¹ is the steam induction pipe;
D³, the exhaust pipe which leads into a tubular condenser C³, which condenser
may be readily placed in the suction pipe of any engine pumping cold water,
and thus have all the cooling influence of the water raised. Fig. 14 is plan
of condenser.
It will be observed that the central delivery valve P, in Illustrations 10
and 13, is provided with wing guides on either side, there being no rod as in
the pump arrangement, Fig. 3.
Fig. 19 shews another modification of working either the central steam
valve, as before described in Figures 3, 10, and 13, or the ordinary slide valve
in general use in modern steam engines. The pump A is here connected to
a steam cylinder of the ordinary kind, with slide valve jacket or case C on the
top.
.
;
It may be well to note here, that the ulterior object of the several methods
of operating the slide valve, shewn in Figs. 1, 3, 10, and 13, as also in
Illustration Fig. 19 now under description, is to dispense with the crank
shaft and fly wheel, if practicable, where only a reciprocating action is
required; they may, however, also be used if preferred. Arm F is fitted to
piston rod E, and is moved to and fro with it; rod G passes freely through
arm F, and is connected to lever H, which lever works on a fixed fulcrum
pin at K; lever L is fixed on the slide valve spindle at M, which works in a
stuffing box in the usual way. A ball N is fixed in any convenient position
on lever L with a view to assist in carrying it past the centre to the end of

page_text: its traverse; this lever may be either flexible or rigid. 0, 0%, are shifting
collars, which may be secured to any required position on rod G by set
screws D, D. The action will be as follows:-When the piston rod moves
in the direction of arrow 1, arm F will move rod G in the same direction by
coming in contact with collar O¹; the short ends of levers H and L, having
slots or elongated holes in them, will then move in the direction of arrow 2;
a screwed stud P is adjusted in the slot of lever H at any determined distance
from the fulcrum pin K, and projects from it into the slot in lever L; the
pin being fixed in lever H will shift up and down in the slot of lever L as it
is moved forward and backward. When stud P is at the lower part of the
slot in lever L its first movement will be comparatively slow, because stud P
describes an arc, and is near that point when a parallel line drawn longi-
tudinally through lever L would strike the extremity of the radial line of
the arc so described; the speed of lever L will therefore be greatest when
both levers H and L are vertical or in a parallel line with each other. At
this point ball N will have received sufficient momentum to carry the valve
the remainder of its traverse; this operation will be repeated at each half
stroke. Fig. 20 is an end view of Fig. 19.
I am aware that various. schemes have been devised with the same
object, copious references to which are given in an elaborate and important
article published in "The Engineer," dated April 15th, 1864, (Offices, 163,
Strand,) under the head of "Steam-moved Valves." This timely publication
will possibly refer to schemes which anticipate some points of this Invention;
I shall readily concede such to any predecessor who may establish a prior
claim.
Having thus described my Invention, and the manner in which the same is
to be carried into effect, what I claim is,-
Firstly, the peculiar combination and arrangement of pump, herein repre-
sented and described, or any modification thereof, the principal feature of
which is the central delivery valve acted upon by two pistons alternately..
Secondly, I claim the combination and arrangement of pump, herein repre-
sented and described, with four pistons and two central delivery valves, as
illustrated in Fig. 16.
Thirdly, I claim the method of adjusting two pistons simultaneously by
placing a tube over the rod, in the manner herein described.
Fourthly, I claim the construction, arrangements, and methods of operating
the central steam valve, herein described and shewn in the Drawing hereunto
annexed, or any mere modification thereof.

page_text: Fifthly, I claim the central valve, above described, when used for blast
engines, exhausters, water engines, syringes, and other machines for which a
mere modification of it is necessary.
In witness whereof, I, the said Stephen Holman, have hereunto set my
hand and seal, the Thirtieth day of April, One thousand eight hun-
dred and sixty-four.
STEPHEN HOLMAN. (L.S.)