IMPROVEMENTS IN STEAM ENGINES
Year: 1884

page_text: I THOMAS CRADDOCK of 23 Waterford Road Fulham in the County of Middlesex
Engineer do hereby declare the nature of my Invention for IMPROVEMENTS IN
STEAM ENGINES to be as follows:-
This Invention in Steam Engines relates to Condenser, Emgine, and Steam
Valves, and is supplementary to those for which I obtained the following Patents.
In 1840 No 8432, 1846 N° 11,473, 1852 N° 51, 1854 N° 1922, 1857 N° 931
and 1857 No 1162, each one of these, and this one there apply for are found in
connection one with the other in perfecting the combination of principles that for
the first time I practically put together before the public.
The boiler that formed the first part of this Provisional Specification originally
is now moved to another place, to it the following allusions refer. The Condenser
improvements are the result of the thought given to the boiler, and as far as suitable
to the Condenser like strutural improvements are embodied in it. These structural
improvements greatly reduce the number of joints, and tubes, by which the steam
passes through the condenser to the air pump; they also greatly simplify the
general structure, whilst, they render it more efficient in practice. But for the
enormous increase in volume the same weight of steam at 6 lbs absolute pressure
assumes, as compared with its volume at 700 lbs per square inch, my judgment
and practical experience united to impel me to make my condenser as well as my
boiler of one tube. I actually do so for small power, by starting with a refrigerative
taper tube, or channel with as much internal area as otherwise is permissible which
suppose to be equal to supply exhaust steam for 680 feet of this taper tube. This
680 feet of tube is wound into circles, the first is 6 feet diameter, and the center
circle is 4 inches in diameter it is then wound back in the reverse direction, and is
used up, when it has made the second circle of 6 feet in diameter. Between these
two layers of tube there is a full half inch, also between all the surfaces, for the due
action of water, or air, to cool them. These tubes are placed flat horizontally in
action; the above though in and out is but one unbroken chanuel, the steam
entering the upper 6 feet circle, returns out at the bottom 6 feet circle, and as it
thus forms in itself a division, I call it a double division. Had it only gon to the
center, it would have been a single division, and had it made four layers of tube,
.

page_text: without break of channel, it would have been a fourfold division, and so on.
I now
pass to a 12 feet outside diameter circle which only differs from the above, in size,
in having the usual inch tube, and in place of one tube there are 23 each 114 feet
long, which work into these inches as a 23 threaded screw, although here are
23 channels, yet as they all enter into and form one division, I call it a double
division. Now this double division in the both cases, is, in each case, a condenser,
the first having 680 feet of taper tube in it; and the last having 2622 feet of inch
tube in it. Let us now place 42 of these divisions one above another, and the both
condensers stand 7 feet high. But the tube now for the first is 28560 feet; and
for the last 110124 feet. I give one other modification of the 12 feet diameter
scale, and still 7 feet high. This is made (say) of 68 variable sized, and threaded
tube screw, made cylinders; the center cylinder is 4 inches outside diameter and
7 feet long, made of 1 tube 114 feet long, and inch diameter as before; the other
67 increasing in internal diameter at least 1 inch as their number increases, so that
they encircle each other from center to cimference of the condenser, and thus placed
vertically these (in this case 68 divisions) make up this condenser. Here the
threads, or tubes, in the 12 feet cylinder, are (say) from 36 to 48. As to length
and number of tubes, and total length in feet, it is near enough here to say, the
total length may here be stated as given in the former illustration. Any one can
see these points are mere matters of practice, and give ample aid thereto. I retain
my old solid metal joint as it is practically the best, it is air tight, and durable so.
The improvements in my Engine. In order to know what my engines have
been, I refer in addition to my previous Specifications to the Mechanic's Magazine
1843 Pages 182 and 516, also 1848 page 241, and 1860 page 55. See also Mining
Journal 1869 Page 526, from which proof positive is obtained that I am here
building on my own foundation. There my pressure was from 100 lbs to 200 lbs
pressure per square inch. Now it is from 100 lbs to 700 lbs per square inch, hence
it is that my three and four cylinder engines are now produced, which expand the
same steam through all of them to the condenser. The pistons of all these cylinders
can be connected to one crank or to as many cranks as pistons. The cylinders of
these engines are so placed, that the crank shaft works at right angles to what it
does in other engines, and the crank works between the two smaller cylinders, the
other one, or two, larger cylinders are over the whole, not necessarily so, but by
preference, in this case; here also the 2.3 or 4 cylinder jackets with valve faces, and
steam passages form one casting. The working cylinders being bushes; See my
Specification 1852 N° 51 as the original of this mode. If desired the 4 cylinders
make two engines, the crranks of which can be at right angles or any angle desired;
the steam still expanding through the 4 cylinders; which then would be cast in
pairs, and bushed as above. In the first case I use one connecting rod for the 4, and
in the latter one for each pair. In some cases it is desirable both with pair, and
fourfold cylinders, to use two cranks acting in the same plune, in such case I use
two connecting rods, which then act as side rods. The 4, 3 or 2 pistons are so
firmly bound together, that in this engine the 2, 3 or 4 pistons act without strain,
through one connecting rod. I effect this object by the aid of my ring cross head,
and my connecting rod, see 1852 N° 51 and the Mining Journal July 1869
Page 526, from that source came the ideas upon which the solidity and practical
result here realized sprung, and now I use any connecting rod, that is best suited
to its use, with little more loss of space than with my own rod. In the tandem
engine I have introduced improvements, attaining the same end, which is rigidty,
reduced height of engine for a given length of stroke, and for a given power, reduced
weight and bulk of engine. Under this head, I further guard against internal con-
densation, by coating the interior of the cylinder lids, and top and bottom of the
pistons, with non conducting material.
The improvements in my engine necessitated
balancing the pressure to which they are subject.
the pistons drive the engine through one crank, I
these in my valves, and mode of
By these improvements when all
make two of my valves serve the

page_text: four cylinders; these two valves have but one eccentric, and valve rod.
I move
the expansive valve from the back of the steam valve on to an independent face,
and work it with its own eccentric, it being set to the normal cut-off, but free to
move forward, is made to act as a substitute for the throttle vale, in regulating the
speed of the engine. The governors being the actuator. In place of the link
motion, I use a simple direct means to start stop and reverse the engine. The
slide valve is defective for expansive engines with the cranks at or near right
angles, this I have before sought to remove but not with complete success, I trust
I have done that now.
D11012
.....

page_text: I THOMAS CRADDOCK of 26 Cedar Road Walham Green S.W in the County
of Middlesex Engineer do hereby declare the nature of my invention for
IMPROVEMENTS IN STEAM ENGINES and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This Invention has for its object Improvements in Steam Engines.
In the provisional Specification of this Invention, apart from Drawings all that
is important is clearly indicated, so that the following reference to the Drawings
present a clear delineation of it. Sheet 1 presents one of its modifications adapted
for use in water or air, with or without self-motion. The same letters refer to all
parts having like functions throughout these Drawings. Thus A indicates the
exhaust pipe and fixed axis of the condenser; B the body of the condenser revolving,
or vibrating on, or round A. If no motion be required all is connected in a fixed
way to A, in this case the passage B to the air pump can be at any desired point.
Suppose it is required to have motion, then all the moving parts are connected
with B, and the immovable parts with A. It is best here to say that owing to the
small scale, the full number of pipes are not seen in the drawings. Suppose the
first double ring (see Fig. 1) made of 100, *" tubes 50 of them proceeding from 5
radial arms B on one side the centre and 50 from 5 radial arms on the opposite
side of the centre, which revolve or vibrate as seen in the horizontal direction; from
these arms B the 100, "tubes C go in the vertical direction (see Fig. 3) and
receiving the steam from B conveys it to E and 120, 1" tubes D, 60 on each side
there receive it, and deliver the condensed product first into F and then into B and
to the air pump. These 220 tubes form the first or outer double ring of a condenser
which is 12 feet in diameter-See Fig. 1.
In Fig. 1 is seen the peculiar formation given to B which renders B so adaptable
for its purpose of simplifying the condenser and surrounding the products with
cold water going to the air pump which prevent their being heated on their
passage through B and A to the air pump. The double ring of 12 feet diameter is
the first of 34 double rings diminishing in diameter as they approach the centre,
and the tubes may diminish to one " and two inch tubes in the smallest double
ring. The tubes C and D are all inserted into half inch strips of good brass. These
strips are cast straight, curved, or even round rings their weight is small as with
the pattern accurately set out it leaves its own cores, so as by passing the proper
size rimer through them the holes tin by mere dipping. The ends of the tubes that
go into their holes being tinned also, the tubes when inserted in the holes are
swelled out on the one side and at the same time swelled to fit the hole tight and
flanged over on what is the inner side when bolted on their seats. In this state a
dip in melted tin renders the whole solid and quite air tight with the two ends
of any desired length of tube thus prepared-further remark on this head is
needless. It may be thought that because the tubes are thickly set in these tube
plates H that they must be quite as close in the whole Division, but 6 inches away
from the joints described any desired separation can be given. At this point, the
reader will see he has a condenser say in the D tube part, 84 inches high composed
of 34 double rings of tube or 68 single rings with the " tubes inside the two rings
that form the double ring and each of these 34 divisions is complete in itself, and
therefore apart from the seat H each may form a separate condenser, and then we
have 34 condensers with surfaces corresponding with diameters. Moreover any
one of these 34 when combined is removable and replacable without interfering

page_text: with any of the then 33 divisions. In former days the weight of my condenser
rested on a toe but here on the rollers G. These rollers can be fixed on a rail and
not attached to the condenser, and any number of rollers can then be used on the
rail with adjusting means to effect equality of weight on each roller. In my former
Specifications to which reference is here given the means of imparting motion to
the condenser are given in detail. When the condenser is placed in a cistern of
water the weight of condenser, the rail and rollers would be borne on the top of
the cistern.
As
The ten radial arms B at bottom, can be reduced to the two seen in section in
Fig. 1. At their extremity increase of width to admit 50 tubes in each one is all
that is required. But at the centre end the area should be equal to that in the
steam pipe, with this modification of the arms these 50 C tubes in their insertion
in the H plate would present a C tube between every D tube; by being so placed
the steam, as it were, goes direct out of the C tube into the D tube, and the sectional
area of E would not require alteration but only its length to admit the 110 tubes
which now would require to be inserted in this plate H. To adapt the tubes C to
thus alternate with the tubes D in this plate H the tubes C require a bend; but
properly made the bend in them, would improve the condenser; As there should
not be a tube in it, without a bend to neutralize expansion and contraction.
seen in Fig. 3 the D tubes would fill up by this modification the void space.
Figures 6 and 7-Show two horizontal modifications of my condenser B B.
present two vertical channels on to which the D tube plates bolt at H; when the
divisions, as before, are made. Here the condenser has 42 divisions in the 7 feet
high, and each of these have 48 D tubes in it. But here the condenser is made in
two half circles; therefore there are 96 tubes in each double layer of the complete
circle. This requires as before two inches deep at H. Here the drawings with
these and the preceding remarks to the D tubes are so plain as to require no more
words on that point. The steam enters the D tubes at B. B. near the centre and
after traversing through them the water and uncondensed products are discharged
into another channel marked B. Fig. 6 does this at the circumference, and Fig. 7
near the centre. Why the air pump channels and steam channels are both marked
B is to fix the reader's attention to the peculiar formation of this B part; he then
perceives that the channel to the air pump has a horizontal channel which
terminates in a vertical continuation to which the water end of the D tubes attach
in the same way as they attach at the steam end; here the large stuffing box is
outside. But the air pump channel stuffing box is seen inside at 2.
The only
difference to note in these two modifications is that in Fig. 7 the tubes D proceed
direct to the outside and works back to near the centre. This is best suited for
condensation in water, where the condenser either stands still or vibrates. Fig 6
is best suited for rotary motion in the air as it proceeds from near the centre to
the circumference. This Fig. 6 shows a square steam central exhaust pipe from
which the D tubes proceed as seen at H at the circumference. This central steam
channel may be round, tapering from 18 or 20 inches diameter at the bottom to
4 inches diameter at the top; in this case the brass strips in which the D tube
joints are made may be in the form of eccentric clips, being bored to fit the round
pipe, would then as on the eccentric, clasp the round pipe. Or they may be rings;
but at the loss of much the half circles practically present.
(Engine) Drawing 2. illustrates the improvement in Engine and mode of
applying and holding the valves to their faces. Fig. 1 is a Front elevation.
Fig. 2, a side elevation and Fig. 3 a plan; it there represents a four cylinder
engine, but is clearly adapted to a double, treble or four cylinder engine; A is the
high pressure cylinder. B the next high pressure, C the next and D the low
pressure cylinder; The 4 piston rods of C and D connect direct on to the ring
cross-head G.-H is the connecting rod, the two piston rods of B are also connected
with this cross-head-See Fig. 2, there also is seen the connection of the A cylinder
piston rod. The ring crosshead G is seen to have a space within it at 2. 2. for the
vibration of the connecting rod H. This crosshead here, as in the following engines

page_text: presents every facility for guide bars, and brasses, but as those and the frame have.
nothing new about them, nothing more need be said on those points. Fig. 4 is a
Front elevation of my 3 cylinder engine with the crank working between the two
high pressure cylinders A and B: with C standing above them. Fig. 5 is a side
elevation and Fig. 6 a plan. Here is the ring crosshead G with H the connecting.
rod. On looking to Figs. 4 and 5; J J is seen, these two parts are seen firmly
connected to the ring cross-head G at that point and at bottom receives the piston
rods A and B; the piston rod of C being fixed to the bar K that braces it altogether
at that point also. In one view of this engine which only differs from this in the
cylinders A and B being 2 feet 7 inches apart, whilst in this they are only 13 inches.
apart, the whole height of engine from centre of crank shaft to top, over all, is but
7 feet 3 inches, with a 2 feet 6 inch stroke, the connecting rod being 6 feet 3 inches
between centres; here we see that by the increase of 18 inches in width between
the cylinders A and B we diminish the height by 5 feet.
Engine Drawing 2. Figs. 7 and 8 show my side rod Engine. A. A. are two
high pressure cylinders receiving alike steam from the boiler; B receives the steam
from them and the cylinder Ď receives its steam from B and passes it to the
condenser. This engine though of four cylinders acts as a three cylinder engine.
FF are the two piston rods of the A cylinders; the piston rod of the B cylinder is
behind that of D which is seen in plan as E; G is the cross head and H the side
rods.
Valve. My valves are plainly shown in my 1846 Specification as applied with
and without the old steam, or valve box; and with the pistons starting together
from the same end of the two cylinders or the opposite ends of the two cylinders,
and in the following Specifications to which reference is here given all is seen as
done by me. Therefore of the valves here it is sufficient to say the Boiler steam
presents itself at O to enter the first cylinder A and the cross hollows convey the
exhaust into the cylinder B from B the exhaust steam presents itself at O in the
centre of the D cylinder valve face, and thereby all must be clear, when it is said
that the two outer hollows seen in the low pressure valve face, have to do with the
exhaust of the D cylinder. It is to the parts indicated by M. N. P. X. X. V. V.
and R. see Figs 9. 10. 11 and 12, also Figs 4 and 5, in the last Figs: these valves
are partly seen at I Fig 4 the end opposite the eccentric rod joint presents itself in
part, and in Fig: 5 the side view is partially seen with the valve rod. Its position
in these two views and Fig. 6 is obvious, and from them the faces of the Cylinders
and how the valves and pressure boxes act is easily understood; on referring to
Fig 9 here 0. 1 and 2 clearly indicates the two valves. To begin with M in the
middle of Fig: 9 we have as there seen a round wrought iron plain plate of 3% of
an inch thick in the present case; on to this is laid two round plates of sheet steel
or copper of the same diameter as the iron plate, these steel plates are best shaped
slightly skimming-dish like with the margins that rivet on to the iron brought to
lic flat on the iron; After rivetting if desirable this joint can be brazed-Thus N
and N are two steam tight, say, round boxes, into which the same steam as it were
acts through these boxes on the back of each of these two valves as on their faces;
the communication takes place through the pipe, and passages seen.
As all the
parts seen in Fig 9 move together the pipes of course do so and in practice may
not be 2 inches in length and 1/2 inch diameter-This part so made is then bolted
in between the two rings see V and V Figs 9 10 and 11 at P what appears as
section lines represent rings of wrought iron ½ inch wide or deep and nearly
1/, thick, these move freely one within the other. In the make of these rings no
fitting is required; on looking to my Specification 1857 N° 931 Sheet 4 Figs. 18
and 30 these rings are substituted by rod iron merely cut to its proper length.
At X fig 10 the incline plane is shown on which these rings rest, and in X Fig 9
is seen a round 1/2 inch plate, on to which is riveted 6 projecting pieces of iron
adapted to the slots seen at X Fig 10 so that by screw pins in this round plate ✗
the whole or any of the area of the pressure boxes is caused to press on the back of
the valves or on the inclined planes through which the slots X are made. From

page_text: what is here said and found in N° 931 of 1857 the parts under notice will be clearly
understood. This V part in addition to its use described, also clasps the two valves,
and to it the valve rod R is jointed so that it being moved by the eccentric its
motion is given to both valves, One joint more and all is clear; which is seen in
Fig: 12 which is an end view in which Z indicates the cylinder valve face, see also
fig: 11 and there Y indicates four rollers as rolling not on the valves or the Cylinder
faces but parallel with them. The axis of these rollers have also their bearings in
the V part See Fig: 12. The reason for these rollers is seen on perceiving that
without them the high pressure steam valve would over-power the low, and the
parts under notice would unfavorably press up against the C cylinder valve face;
these rollers prevent that so that the pressure is variable at pleasure on either or
both of the valves by the screw pins above referred to which increases or decreases
the area of the pressure boxes, that act on the back of either valve. The rollers
of 1857 are the best. Figs 13 and 14 show the part of my invention relating to
internal condensation by the interior of bottom and top lids of steam Cylinders and
the top and bottom of their pistons; A is the body of a piston that indicates first
the lip all round as D, on lids and pistons, under this lip is fitted first a 1/2 inch or
more of wood or other suitable material and over that Asbestos Millboard or
Vulcanized rubber C these also go under the lip d and are screwed to the wood b
or such substance as is found best adapted for the purpose, All here said of the
piston applies equally to the lids of the Steam Cylinder Fig: 14 is the plan that
relates to Steam Cylinder lids and pistons.
Before stating my Claims in this invention it is but right that I say that in all
its parts the root or origin of those parts is found in my former Specifications,
beginning with 1840 and extending to 1857, reference to which is given in this
specification.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
First. The combination of parts indicated by A B E F and H which form the
seats, joints and communication between the steam cylinder and air pump, so that
the D or the C and D) channels either as taper, or, ordinary tube of any desired
length complete the condenser substantially as hereinbefore described and illustrated
by sheet 1 of the accompanying Drawings.
Second. The combination of my ring crosshead with piston rods, connecting rods,
cranks and four cylinders, through which to expand the steam, seen in drawing in
tanden form, but adapted to effect the same object with any number of cranks up
to four; the parts J J and K with crank between the A and B cylinders are
included also the two small cylinders combined with cylinders B and D, sub-
stantially as hereinbefore described and illustrated by sheet 2 of the accompanying
Drawings.
Third. The method of holding the valves to their faces and the arrangement for
working two valves with one eccentric as herein before described, but I do not claim
the valves themselves in this specification they having formed the subject of my
previous patent No 11473 A.D. 1846.
Fourth. Covering the non-rubbing surfaces of pistons, and the inner side of
cylinder covers with layers of non-conducting material for the purpose of preventing
internal condensation as shewn and described in Figs 13 and 14.
Dated this 30th day of September 1884.
THOMAS CRADDOCK.