Improvements in Steam Fire Engines and Pumping Engines.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Steam Fire Engines and Pumping Engines.
JAMES CADOUX HUDSON, 75, Upper Ground Street, Blackfriars Road, London,
Engineer, do hereby declare the nature of this invention to be as follows:-
-
In portable, floating, and fixed steam fire or pumping engines of the rotating
pattern where the movement of the piston is controlled by a crank and connect-
ing rod
or crosshead, and with fire pumps having one, two, or three double
acting high pressure steam cylinders it has been the practice to use a slide
valve to the steam cylinder worked by an eccentric or other device and cutting
off steam at about 75 per cent. of the stroke.
In
with
11
per
a
not occur at
ย
treble
My improvement consists in supplying each steam cylinder with a variable
cut off valve so that when starting the engine a cut off of 75 per cent. more or
less can be used and after the engine is at work the cut off can be reduced and
varied to suit the work to be done thus effecting considerable economy in the
consumption of steam and still enabling the engine to be more readily started
than if a fixed expansion of 25 per cent. or 50 per cent, was in use.
more difficult to start
a single cylinder pumping engine it is
a high grade of expansion than with low grade, and in
double cylinder high pressure engine self starting does
cent. or in
all points if the cylinder cut off is less than 50
if less than 33% per cent. Whereas with a variable expansion the engine
can be started at a low grade of expansion and subsequently increased to as high
a grade as is desirable. The variable cut off can be obtained by means of adjust-
able plates working on the back of main slide valve and moved by separate
eccentrics as in a well known arrangement for ordinary steam engines or some
other suitable device. For single, double, or treble cylinder engines I can also
use an expansion arrangement by means of a roller attached to the end of slide
rod, or to a vibrating link attached to slide rod, the roller running on a cam on
crankshaft, the cam being formed to give any desired degree of expansion and
a proper opening and closing of the steam, exhaust, pre-exhaust and compression.
The roller is kept in contact with the cam by the slide rod passing out of the
steam chest being of sufficient area to allow the steam to force the rod out of
the steam chest and keep the roller in contact with the cam, or I assist the action
by means of a spring. I can also place two or more such cams side by side formed
for various degrees of expansion and allow the roller to engage with one or the
other of these as desired giving the roller a movement across the face of these
cams. The vibrating link carrying roller will also allow the slide valve to be
moved and the engine thus started from a position when the slide valve might
otherwise be inoperative. In engines having two or more cylinders the degree
of expansion will be altered simultaneously by connecting the variable expansion
gear of each together. Since I should generally use a steam cylinder of large
proportionate area to the pump cylinder I obtain a fire pump which will work
at high grade of expansion and economically and deliver a large quantity of

page_text: water at moderate pressure which is desirable when working through short lines
of hose and by working with a lower grade of expansion will also deliver a less
quantity of water at much higher pressure which is desirable when working
through long lines of hose. These improvements will apply to other pumps than
fire pumps.
Datod this 25th lov of Luna 1808
Improvements in Steam Fire Engines and Pumping Engines.
JAMES CADOUX HUDSON, 75, Upper Ground Street, Blackfriars Road, London,
Engineer, 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:-
-
In portable, floating, and fixed steam fire or pumping engines of the rotating
pattern where the movement of the piston is controlled by a crank and connect-
ing rod, or crosshead, and with fire pumps having one, two, or three double
acting high pressure steam cylinders, it has been the practice to use a slide
valve to the steam cylinder worked by an eccentric or other device and cutting
off steam at about 75 per cent. of the stroke.
My improvement consists in supplying each steam cylinder with a variable
cut off valve so that when starting the engine a cut off of 75 per cent. more or
less can be used; and after the engine is at work the cut off can be reduced and
varied to suit the work to be done-thus effecting considerable economy in the
consumption of steam and still enabling the engine to be more readily started
than if a fixed expansion of 25% or 50% was in use. In a single cylinder
pumping engine it is more difficult to start with a high grade of expansion than
with a low grade, and in a double cylinder high pressure engine self starting
does not occur at all points if the cylinder cut off is less than 50%; or in a
treble if less than 33 per cent. Whereas, with a variable expansion the engine
can be started at a low grade of expansion and subsequently increased to as high
a grade as is desirable. The variable cut off can be obtained by means of adjust-
able plates working on the back of main slide valve and moved by separate
eccentrics as in a well known arrangement for ordinary steam engines or some
other suitable device. For single, double, or treble cylinder engines I can also
use an expansion arrangement by means of a roller attached to the end of slide
rod, or to a vibrating link attached to slide rod, the roller running on a cam on
crankshaft, the cam being formed to give any desired degree of expansion and
a proper opening and closing of the steam, exhaust, pre-exhaust and compression.
The roller is kept in contact with the cam by the slide rod passing out of the
steam chest being of sufficient area to allow the stram to force the rod out of
the steam chest and keep the roller in contact with the cam, or I assist the action
by means of a spring. I can also place two or more such cams side by side formed
for various degrees of expansion and allow the roller to engage with one or the
other of them as desired giving the roller a movement across the face of these
cams. The vibrating link carrying roller will also allow the slide valve to be
moved and the engine thus started from a position when the slide valve might
otherwise be inoperative. In engines having two or more cylinders the degree
of expansion will be altered simultaneously by connecting the variable expansion
gear of each together. Since I should generally use a steam cylinder of large
proportionate area to the pump cylinder I obtain a fire pump which will work

page_text: at high grade of expansion and economically and deliver a large quantity of
water at moderate pressure which is desirable when working through short iines
of hose and by working with a lower grade of expansion will also deliver a less
quantity of water at much higher pressure which is desirable when working
through long lines of hose. These improvements will apply to other pumps than
fire pumps.
In order that my said invention may be most fully understood and
readily carried into effect 1 will proceed to describe the drawings hereunto
annexed.
readily carried into effect I will proceed to describe the drawings hereunto
annexed.
DESCRIPTION OF DRAWINGS.
Fig. 1 is a sectional front elevation of a double cylinder steam fire or pumping
engine fitted with one arrangement of variable expansion gear according to my
improvements.
Fig. 2 is a part side elevation of the same.
Fig. 3 is a plan of same.
Fig. 4 is a part sectional front elevation of a single double or treble cylinder
steam fire or pumping engine fitted with a modified fixed expansion arrangement
the slide valve being controlled by cam roller and vibrating link.
Fig. 5 is a part side elevation of the same.
Fig. 6 is a part sectional front elevation of a single, double or treble cylinder
steam fire engine fitted with a cam and roller variable expansion gear the steam
distribution being by piston valve in place of ordinary slide valve.
Fig. 7 is a side elevation of the same.
Fig. 8 is a sectional plan of same shewing variable expansion gear.
Fig. 9 is a front elevation of a three cylinder engine fitted with variable
expansion gear consisting of eccentrics, main & cut off valves and the like as
in a steam engine of ordinary construction.
Fig. 10 is a part elevation of the same.
Fig. 11 is a plan of cylinders.
Fig. 12 is a sectional plan shewing valve gear of centre cylinder.
Fig. 13 is a front elevation of a part of three cylinder engine fitted with the
cam and roller variable expansion gear.
Fig. 14 is a side elevation of the same.
Fig. 15 is a plan of cylinders.
Fig. 16 is a sectional plan shewing valve and adjustment gear.
Referring now to Figs. 1, 2 & 3 (A) (A) are the steam cylinders, (B) the
crankshaft of ordinary construction, (C) the main slide valve driven by eccen-
tric (D) and valve rod (E) the cut off valves (F) (1) being driven by the eccen-
tric (G) and valve rod (H), this rod passes out of top of steam chest (I) through
stuffing box (J) and is connected to the expansion adjustment gear on the top
of cylinders (A) (A). The cut off valves (F) (F) are connected to the valve
rod (H) by the right and left hand screw (K) (K) and by rotating the rod (H)
the valves (F) (F) are adjusted by being opened or closed as may be desired,
the valve rod (H) being rotated by means of wheel (L) and worn (M) carried
on spindle (N) and supported by brackets (0). This part of the adjustment
gear is in duplicate for each engine the valves (F) (F) of each cylinder (A)
being adjusted simultaneously in one operation by turning the hand wheel (P)
attached to the end of worm spindle (N), this spindle being extended to the gear
on the opposite cylinder and thus being common to both. The valve rod (H)
is connected to the eccentric (6) by a swivel joint (Q) which also forms an oil
reservoir (R)--thus the rod (H) is free to revolve, and the opposite end of the
rod (H) passing through the wheel (L) is free to move upwards or downwards
under the action of the eccentric (G)-the valve rod (H) being rotated by
keys (S) (S) fixed to the wheel (L) and sliding in slots or grooves (T) (T) in the
valve rod (H). A cap (1) attached to the bracket (0) on wheel (L) covers and
protects the ends of valve rod (H) and also forms an oil reservoir.
A part of the worm spindle (N) is screwed at (V) to receive a nut (W) to

page_text: which is attached an index (X) and by revolving the spindle (N) either in one
direction or the other the nut (W) and index (A) is moved to the right or to the
left, thus the position of the nut (W) on the screw (V) indicates the relative
position of the cut off valves (F) (F). The nut (W) and screw (\) is protected
by a cover (1) attached to the bracket (0) and having a slot (Z) to receive the
index (X) of the nut (W), and upon the outside of the cover (Y) is engraved
the various grades of cut off to which it may be desired to adjust the valves (r) (c)
the screw (1), nut (W) and index (X) with cover (Y) may be situated in any
other position on the worm spindle (N) such as in the centre as shewn at (X)
in dotted lines.
Referring to Figs. 4 & 5 (A) is the steam cylinder (B2) the crankshaft, (12)
the steam chest containing the slide valve (C) of ordinary construction driven
by a cam (2) and valve rod (E) to which is attached the roller (2) and link
or lever (G) vibrating on the pin (H) the outer surface of the cam (*) which is
in contact with the roller (F) is shaped to give the requisite movement to the
slide valve (C) for any fixed points of cut off release and compression. The
roller (2) is held in contact with the cam (1) by reason of the downward
pressure which the rod (E2) receives from the steam and this may be further
assisted by a spring (I) having one end attached to the link or lever (G2) and
the opposite end connected to some part of the engine frame (J). To enable
an engine having a high grade of cut off to be more readily started the valve (C)
may be moved by a handle (h) at the end of the lever (G) or by any other suit-
able device.
In Figs. 6, 7, & 8 (A) is the steam cylinder (B) the crankshaft (3) the steam
chest containing the piston valve (C) driven by the cam (D³) and roller (F3)
and valve rod (3). The cam (1) is formed in such a manner as to give approxi-
mately the same movement to the valve (C) as would be effected by placing side
by side a number of separate cams formed respectively to give various grades of cut
off, release, and compression. Thus with the roller (F) in the position shewn
a high grade of cut off of say 25% and any desired point of release and com-
pression would be obtained, then by moving the roller (F) to the right to the
extreme opposite side of the cam (13), a low grade of cut off say of 80% and
the same or any other desired point of release and compression would be obtained
and any intermediate position of the roller would give a grade of cut off between
these two extremes. The moving of the roller (3) across the face of the cam (1)
may be performed by a link or lever (G3) having fork or jaw (H) between which
the roller (F) revolves, this lever (G³) is attached at its opposite end to a
spindle (13) supported and vibrating in a bearing or boss (J³) on a part of the
engine frame. Thus the levers or links (G) (G³) together with the rollers (F)
(F3) may be moved transversely across the face of the cams (D) (D³) and held
in any desired position. (This movement may be performed by a screw (K³)
at the end of spindle (13) and a hand wheel (L) and nut (M³) supported by a
bracket (N) or any other suitable device may be employed to give the required
movement to the roller-a modified arrangement is shewn in dotted lines
when (0) is a lever vibrating on a pin (P3) having a forked end (3) to engage
clutch (R) on spindle (1) the opposite end having handle (S3). This lever may
be held in any desired position by a spring stop (T) or any other suitable
device. The spindle (1) being common to both engines the adjustment of cut
off is effected simultaneously in one operation Figs. 9, 10, 11 & 12 (A) (A³) (A$)
are the steam cylinders, (B) the crankshaft. (I) (I) (I) the steam chest con-
taining main and expansion valves ((") (F³), ((%) (F), the valves of the two
outside cylinders (A) (A) being driven direct upwards by the eccentrics (D) (G)
and valve rods (E) (H) all as described in connection with Figs. 1, 2 & 3.
The valves (C5) (F5) of the centre cylinder (A) are driven by the eccen-
trics (D) (G) bell crank levers (L') (L) vibrating on rocking shaft (K) the
valve rods (H) (H) (H) of the expansion valves (F) (F³) (F) are continued
upwards and through the stuffing boxes (J*) (J³) (J) for connection to any suit-

page_text: able arrangement of adjusting gear preferably that described in connection with
Figs. 1, 2 & 3.
Figs. 13, 14, 15 & 16 (Aº) (A) (A") are the steam cylinders (I) (Iº) (1º) the
valve chests containing piston valves similar to that described in connection
with Fig. 6, (K) is a shaft revolving in bearings or brackets (L) (L) and
receiving motion from the crankshaft (B) by spur gearing or any other suitable
device. (1) (1) (16) are variable cut off cams being similar to the one described
in connection with Figs. 7 & 8 the piston valve receives its motion through the
roller (F) and the valve rod (E). In this case the cams (D") are moved trans-
versely by sliding the shaft (K) in the bearings (L) thus by moving to the right
or to the left a high or low grade of expansion and any desired point of release
and compression may be obtained. The required transverse movement to the
shaft (K) may be imparted by a screw (M), hand wheel (N) and running
nut (0) engaging with the end of shaft (K) or any other suitable device may
be employed to give this movement such as the lever (0) and clutch (R3) des-
cribed in connection with Fig. 8. The shaft (K) being common to each of the
cams (D) the cut off for each cylinder is performed simultaneously at one
operation. This arrangement of variable cut off cams is equally applicable to
a double engine also the arrangement of cams shewn in connection with the
double engine Figs. 6, 7 & 8 is equally applicable to a single or three cylinder
engine, also the arrangement of cam & roller described in connection with Figs. 4
& 5 applies to either single, double or treble engines.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is;-
Firstly. In portable steam fire engines having one two or three simple cylinders
I claim the arrangement of working the steam expansively to a higher grade
than heretofore by means of expansion gear having main slide and cut off slide,
or main slide and variable cut off slide to the steam cylinder or cylinders vari-
able at will or other arrangements to accomplish the same end or by means of
cam or cams formed and arranged to allow a fixed or variable cut off to the slide
valve or piston valve of steam cylinder or cylinders as described and illustrated
and for the purposes specified and explained.
Secondly. In Hoating or stationary steam fire engines and pumping engines
having one, two or three simple cylinders I claim the arrangement of working
the steam expansively to higher grade than heretofore by means of expansion
gear having main slide, and cut off slide or main slide and variable cut off slide
to the steam cylinder or eylinders variable at will or other arrangement to accom-
plish the same end or by means of cam or cams formed and arranged to allow a
fixed or variable cut off to the slide valve or piston valve of steam cylinder or
cylinders as described and illustrated and for the purpose specified and explained.
Dated this 25th day of March 1899.
JAMES CADOUX HUDSON.