IMPROVEMENTS IN DIRECT-ACTING STEAM PUMPS
Year: 1877

page_text: LETTERS PATENT to William Craig, of 76, Manor Road, New Cross, in the
County of Kent, for the Invention of "IMPROVEMENTS IN DIRECT-ACTING
STEAM PUMPS."
:
Sealed the 18th January 1878, and dated the 19th July 1877.
PROVISIONAL SPECIFICATION left by the said William Craig at the Office
of the Commissioners of Patents on the 19th July 1877.
WILLIAM CRAIG, of 76, Manor Road, New Cross, in the County of Kent. IM-
PROVEMENTS IN DIRECT-ACTING STEAM PUMPS."
My Invention relates to that class of steam pumps in which the main steam slide
valves are actuated by the steam without the intervention of eccentrics, cranks, or
cams, the auxilliary slide valves for governing the action of the steam upon such
main slide valves being actuated by the main steam piston or piston rod.
My said Invention is applicable to such steam punips whether working hori-
zontally, vertically, or obliquely, and whether the pump be of the plunger or of the
single or double-acting piston type, but the special object of the improvements is
to produce a vertical direct-acting steam plunger or piston pump without cranks,
eccentrics, or cams, adapted for feeding boilers and other purposes, which, besides
being simple and cheap in construction, shall act with greater certainty than the
vertical direct-acting steam pumps with steam-moved valves heretofore in use. In
order to effect this object I employ the usual arrangement of steam cylinder and
pump barrel in line with each other, and either formed in one single casting or in
various parts properly secured together; but instead of forming or mounting the
valve chest on the side of the steam cylinder, as heretofore usually practised, I
place the said valve chest on the end or cover of the stean cylinder opposite to that
at which the pump barrel is placed, such valve chest with its contained valves being
by preference placed concentrically and in line with the axis of the steam cylinder
itself, but they may be placed eccentrically with regard to the said axis.

page_text: The steam valves are of the sliding cylindrical kind, consisting of a main valve
for governing the inlet and outlet of the steam to and from the steam cylinder, and
of an auxilliary valve preferably arranged to work within the main valve for
governing the inlet and outlet of steam to and from the faces or ends of the said
main valve, and I sometimes employ in connexion with the aforesaid main steam
valve a double set of ports and passages, formed in the opposite sides of the valve
chest, and communicating with the two ends of the steam cylinder, whereby the
said valve is more perfectly balanced, and the same amount of travel thereof effects
a greater opening of port or area of steam passage than is usually obtained with
this class of steam valve.
In order to operate the auxilliary valve at the proper times to govern the admission
of steam to and from the faces or ends of the main steam valve when the main
steam piston approaches the end of its stroke, I employ a rod connected to the said
auxilliary valve, which rod extends into a hole or recess formed in the piston and
piston rod or pump plunger, such rod being acted upon by suitable parts connected
to the piston coming in contact with stops on the said rod as the piston approaches
the end of its stroke in either direction.
The ports and passages in the main steam and auxilliary valves are so arranged
in relation to each other and to the ports and passages in the valve chest, and the
surfaces of the auxilliary valve are so adapted to those of the main steam valve, that
the reduced pressure consequent upon the exhaustion of the steam from one side or
end of the main and auxilliary valves assists the steam pressure acting on the other
side or end of the main and auxilliary valves, tending to hold them both firmly and
with certainty in their proper positions, while the main steam piston is making its
stroke, and until the auxilliary valve is moved thereby, preparatory to a fresh
stroke of the main steam valve. This effect takes place especially when a condenser
is employed in connexion with the steam cylinder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Craig in the Great Seal Patent Office on the 19th
January 1878.
WILLIAM CRAIG, of 76, Manor Road, New Cross, in the County of Kent.
PROVEMENTS IN DIRECT-ACTING STEAM PUMPS."
IM-
My Invention relates to that class of steam pumps in which the main steam slide
valves are actuated by the stearn without the intervention of eccentrics, cranks, or
cams, the auxilliary slide valves for governing the action of the steam upon such
main slide valves being actuated by the main steam piston or piston rod.
In
My said Invention is applicable to such, steam pumps, whether working horizon-
tally, vertically, or obliquely, and whether the pump be of the plunger or of the
single or double-acting piston type, but the special object of the improvements is to
produce a vertical direct-acting steam plunger or piston pump without cranks,
eccentrics, or cams, adapted for feeding boilers and other purposes, which, besides
being simple and cheap in construction, shall act with greater certainty than the
vertical direct-acting steam pumps with steam-moved valves heretofore in use.
order to effect this object I employ the usual arrangement of steam cylinder and
pump barrel in line with each other, and either formed in one single casting or in
various parts properly secured together; but instead of forming or mounting the
valve chest on the side of the steam cylinder, as heretofore usually practised, 1 place
the said valve chest on the end or cover of the steam cylinder opposite to that at
which the pump barrel is placed, such valve chest with its contained valves being
by preference placed concentrically and in line with the axis of the steam cylinder
itself, but they may be placed eccentrically with regard to the said axis.
The steam valves are of the sliding cylindrical kind, consisting of a main valve
for governing the inlet and outlet of the steam to and from the steam cylinder, and
of an auxilliary valve preferably arranged to work within the main valve for
governing the inlet and outlet of steam to and from the faces or ends of the said
main valve, and I sometimes employ in connection with the aforesaid main steam
valve a double set of ports and passages formed in the opposite sides of the valve
chest and communicating with the two ends of the steain cylinder, whereby the
said valve is more perfectly balanced, and the same amount of travel thereof effects
a greater opening of port or area of steain passage than is usually obtained with
this class of steam valve.
In order to operate the auxilliary valve at the proper times to govern the
admission of steam to and from the faces or ends of the main steam valve when the
main steam piston approaches the end of its stroke, I employ a rod connected to
the said auxilliary valve, which rod extends into a hole or recess formed in the piston
and piston rod or pump plunger, such rod being acted upon by suitable parts con
nected to the piston, coming in contact with stops on the said rod as the piston
approaches the end of its stroke in either direction.
The ports and passages in the main steam and auxilliary valves are so arranged
in relation to each other, and to the ports and passages in the valve chest, and the
surfaces of the auxilliary valve are so adapted to those of the main steam valve,
that the reduced pressure consequent upon the exhaustion of the steam from one
side or end of the main and auxilliary valves assists the steam pressure acting on
the other side or end of the main and auxilliary valves, tending to hold them both
firmly and with certainty in their proper positions, while the inain steam piston is
making its stroke, and until the auxilliary valve is moved thereby, preparatory to a
fresh stroke of the main steam valve. This effect takes place especially when a
condenser is employed in connexion with the steam cylinder.
Figure 1 of the Drawings represents a vertical section of a direct-acting steam
plunger pump constructed in accordance with my Invention, the steam valves

page_text: being removed in order to shew more clearly the steam and exhaust in ports in u
valve chamber.
Figure 2 is a vertical section at right angles to Figure 1, with valves in position;
Figure 3 an elevation, and Figure 4 a half plan of same.
Figures 5, 6, and 7 are enlarged elevations and a section of the valves removed
from the valve chest.
Figure 8 is a horizontal section through the valves and valve chest at line A, A,
of Figures 1 and 2.
Figure 9 is a partial vertical section of the arrangement adapted to a double-
action piston pump.
Similar letters refer to like parts in all the Figures.
A is the steam cylinder; B, the piston; C, the pump barrel; D, the plunger
(in Figures 1, 2, and 3); and D¹ the pump piston, and D³ the piston rod in Figure 9.
The plunger D or piston D³, as the case may be, passes through stuffing boxes E
and F in the usual way; G is the valve chest bolted or otherwise secured on to the
end of the steam cylinder A; H is the cylindrical main valve for governing the inlet
and outlet of the steam to and from the steam cylinder A, such main valve H being
actuated, as herein-after explained, by steam admitted to the ends thereof by the
auxilliary valve I, which latter is operated at the proper time by the rod J attached
thereto; the said rod J extends into the hole or recess K formed in the piston B and
plunger C, Figures 1 and 2, or piston B and piston rod D2, Figure 9, as the case
may be. This rod J is acted upon by the tappet or catch piece L (screwed or
otherwise fixed into the end of the hole or recess K), coming in contact with the
stop or enlargement M of the rod J, as the piston B approaches the end of its
downward stroke, and against the stop or enlargement N as it approaches the end
of its upward stroke.
The main cylindrical steam valve H is adapted to slide in the cylindrical steam
chest in the manner now well known in connexion with this class of valves; it has
formed in it two grooves H', H2, which communicate by the opening O at all times
with the chamber P, into which steam enters from the boiler through the passage Q.
The grooves H1, H2, also communicate with the chamber R opposite to the
chamber P, conducting steam from the latter thereto, by which means the pressure
of steam in the chamber P acting against the surface of the main valve H exposed
at the opening O is balanced. S, S, are the exhaust recesses in the main steam
valve, corresponding to the exhaust ports T, T, in the valve chest, such exhaust
ports or passages uniting into one passage U leading to the exhaust outlet V ;
W, W, are steam ports and passages leading to the lower end of the steam cylinder,
and X, X, are steam ports and passages leading to the upper end of the steam
cylinder.
The auxilliary valve I is adapted to slide in a cylindrical hole formed through the
main steam valve H, and as shewn in Figures 2 and 6, may be formed in two halves
for convenience of introduction into the main steam valve, the two halves being
united by the rod J passing through them, and secured by a nut at the top, as shewn.
The auxilliary valve I has formed at its ends, heads, or collars, which limit its
endlong or sliding movement in the main steam valve.
Instead of forming the auxilliary valve in two halves, it may be made in one
piece by leaving one of the heads or collars loose, and fixing it to the auxilliary
valve by screwing it thereto, or by other suitable means after the said auxilliary
valve has been passed into the main steam valve. In the auxilliary valve are
formed the small passages I¹, 11, 12, 12, adapted to correspond alternately, according
as the auxilliary valve is moved in one direction or the other in the main valve,
with small passages or ports Y, Y, Z, Z, formed in the latter for the purposes to be
hereafter explained.
The suction and delivery valve boxes are connected to the nozzle C¹, Figures 1,3,
and 9, as may be convenient and suitable.
In Figures 1, 2, and 3 the base plate, pump barrel, distance piece, and steam
cylinder are shewn cast in one piece.

page_text: In Figure 9 the pump barrel is shewn cast in one piece, and the steam cylinder
distance piece and pump cover in another, but it is evident that this constructive
detail may be varied according to circumstances and convenience.
The action of the parts is as follows-When the piston B arrives at or near the
end of the up stroke the tappet or catch piece L comes in contact with the stop or
enlargement N, and raises the rod J and with it the auxilliary valve I until the
ports and passages I', I', come opposite the ports or passages Y, Y, in the main
valve H. Steam then passes from the groove H' through the passages I¹, I¹, into
the space below the auxilliary valve I, and acting on the under sides of the auxilliary
and main valves raises them both until the groove H¹ comes opposite the steam
ports X, X, thus admitting steam to the top side of the piston B. The same upward
movement of the main valve brings the exhaust recesses S, S, over the steam
ports W, W, thus opening communication between the exhaust outlet and the under
side of the piston. When the piston B arrives at or near the end of the down
stroke the tappet or catch piece L comes in contact with the stop or enlargement M
and draws down the rod J, and with it the auxilliary valve I, until the ports or
passages I, I, come opposite the ports or passages Z, Z, in the main valve H. Steam
then passes from the groove H2 through the passages I², I², into the space above the
auxilliary valve I, and acting on the upper side of the auxilliary and main valves
presses then both downwards until the groove H2 comes opposite the steam
ports Y, Y, thus admitting the steam to the under side of the piston B. The same
downward movement of the main valve brings the exhaust recesses S, S, over the
steam ports Z, Z, thus opening communication between the exhaust outlet and the
upper side of the piston. In Figure 2 the parts are shewn in the positions last
described, suitable for the ascent of the piston.
It will be understood that the movement of the auxilliary valve upwards, which
brings the ports or passages I', I', opposite the ports or passages Y, Y, in the main
valve H, so as to admit steam from the groove H' to the space below the said
auxilliary and main steam valves, also brings the ports or passages I², I², opposite
the ports or passages Y', Y', in the main valve, which open into the exhaust recesses
thereof, by which means the steam which has acted above the auxilliary and main
valves to press them downwards is allowed to escape, and that conversely the
movement of the auxilliary valve downwards which brings the ports or passages I2, I²,
opposite the ports or passages Z, Z, in the main valve H, so as to admit steam from
the groove H2 to the space above the said auxilliary and main steam valves, also
brings the ports or passages I', I', opposite the ports or passages Z', Z', in the main
valve which open into the exhaust recess thereof, by which means the steam
which has acted below the auxilliary and main valves to press them upwards is
allowed to escape.
In the arrangement above described and illustrated in Figures 1 and 2, a set of
steam and exhaust ports and passages are used on opposite sides of the main steam
valve, whereby, as herein-before described, the said valve is more equally balanced
than when one set only is used, and a greater opening of port with a given amount
of travel of valve may be obtained than is usual with this class of steam valve,
but I do not confine myself to that arrangement, as in some cases I employ only one
set of such ports and passages, and then only one set of small ports I¹ and I² is
required in the auxilliary valve.
Cushioning the steam at the end of the stroke of the steam piston may be
effected by causing the steam passages to enter the cylinder at a short distance
from the ends in the manner well known in connexion with this class of direct-
acting steam pump.
To enable the auxilliary valve I to be moved by hand when necessary, the rod 2
passes through the stuffing box 3 at the top of the valve chest, and carries at its
lower end a pin 4, the head of which enters a recess in the rod J, the nut 5 which
screws on to the rod J encircling the pin 4. The head of the pin may be made to
act upon the rod J, and consequently the auxilliary valve attached thereto, by
drawing out or pushing in the rod 2, the play of the head of the pin 4 in the

page_text: recess of the rod J allowing of the motion of the latter with the auxilliary valve
when the pump is at work without giving motion to the rod 2.
In the Drawings the auxilliary and steam valves and valve chest are shewn
concentric with the steam cylinder, and such arrangement is in most cases preferable
on account of simplicity and facility of manufacture, but I do not confine myself
to their arrangement in that way as they may be placed eccentrically with regard
to the axis of the steam cylinder without departing from my Invention.
In the Drawing the pump and cylinder are shewn vertical, but they may be
arranged horizontally or obliquely, as may be required.
Having now described the nature of the said Invention and the manner in which
the same is to or may be performed, I would have it understood that I make no
claim to the parts separately, but what I do claim as my Invention is,―
Firstly. Arranging the cylindrical steam-moved valves and valve chests of direct-
acting steam pumps on the ends or covers of the steam cylinders, in such manner
that the said valves shall operate in line with or parallel to the axes of the said steam
cylinders, as herein-before described and illustrated in the Drawings.
Secondly. The employment of a double set of steam ports and passages on
opposite sides of
cylindrical steam-moved valve, substantially as herein-before
described and illustrated in the Drawings and for the purposes set forth.
Thirdly. The arrangement and combination of parts for operating the auxilliary
valve I by the motion of the steam piston, such parts being wholly contained
within the steam cylinder and steam chest, and consisting of the rod J connected
with the auxilliary valve I, the hole or recess K in the piston and pump plunger or
piston rod, the stops N and M on the rod and the tappet or catch piece L fixed to the
piston, the whole arranged, combined, and operating substantially as herein-before
described, and illustrated in the Drawings.
Fourthly. The construction and use of direct-acting steam pumps, wherein the
slide valves are operated in line with the cylinder, with or without the double sets
of ports and passages in the valve chest, and having the auxilliary valve operated
by the movement of the steam piston by means of parts wholly contained within
the steam cylinder and valve chest, the various parts being arranged, combined, and
operated substantially as herein-before described and illustrated in the Drawings,
In witness whereof, I, the said William Craig, have hereunto set my hand
and seal, this Eighteenth day of January, in the year of our Lord One
thousand eight hundred and seventy-eight.
WILLIAM
DIY
CRAIG. (L.S.)