IMPROVEMENTS IN STEAM ENGINES
Year: 1864

page_text: LETTERS PATENT to William Edward Gedge, of the Firm of John Gedge
and Son, of No. 11, Wellington Street, Strand, in the County of Middle-
sex, Patent Agent, for the Invention of "IMPROVEMENTS IN STEAM
ENGINES." A communication from abroad by Arthur de Montméja, of
20 Faubourg St. Martin. Paris. France.
PROVISIONAL SPECIFICATION left by the said William Edward Gedge
at the Office of the Commissioners of Patents, with his Petition, on the
16th December 1864.
I, WILLIAM EDWARD GEDGE, of the Firm of John Gedge and Son, of No.
11, Wellington Street, Strand, in the County of Middlesex, Patent Agent,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
STEAM ENGINES," (a communication to me from abroad by Arthur de
Montméja, of 39, Faubourg St. Martin, Paris, France,) to be as follows:-
This Invention consists in a new mode of distributing the steam, reversing
motion by apparatus independent of the engine, and the application of these
improvements to engines with fixed or with oscillating cylinders. The engine
is composed of an oscillating cylinder in which moves a piston acting directly
on the horizontal shaft. This latter carries but one eccentric for the feed
pump and one grooved pulley to receive the belt or band of the regulator.

page_text: The feed pump may also be worked by one of the pivots or trunions of the
cylinder by means of a small lever arm perpendicular to the trunion, and
which joins on to the end of the piston rod of the pump. The entire modifi-
cation bears on the distribution of the steam and the reversing action.
Firstly, as to the distribution of the steam.-The oscillating cylinder is sup-
ported by two pivots or trunions, which are received in bearings in the framing
as in ordinary engines, excepting that they pass a little way beyond these
bearings; and further, one of them, more bulky than the other, is hollowed,
following its axis by a conical cavity, which may be compared to the seat of a
stop-cock. In this conical cavity, the base of which should be rather large
compared with its height, is received a key in form of a truncated cone. The
key and its seat are ground to fit exactly the one on the other. This latter,
which is nothing but the pivot of the cylinder, is pierced with two orifices
diametrically opposed to each other, and in which fit the tubes that are to
conduct the steam over or under the piston, supposing the machine to be
vertical. They give exit to the steam which has acted on this same piston.
On the accompanying Sheet of Drawing, forming part of this Provisional
Specification, Figure 1 represents a section of this part. The key (as shewn
Figure 2) is constructed like that of an ordinary cock, in the middle of which
two cuts or slots have been made, separated by a full part, the length and the
breadth of which are exactly the same as that of the orifices of the seat. It
will be at once understood that the key being placed in the seat may take
successively the several positions shewn Figures 3, 4, and 5, in relation to the
orifices with which the seat is pierced. These Figures represent transverse
sections, and consequently the key is only represented by the full or solid
part separating the two cuts or slots before mentioned. This full space I
term the diaphragm. Suppose the pipes A communicating with the upper
part of the cylinder, and those B with its lower part; suppose, on the other
hand, that all the points a are in communication with the boiler, and the
points 6 with the atmosphere, what would be the consequence? At Figure 3
the machine would be at dead point, at Figure 4 the steam would act on the
upper face of the piston, and that which was beneath the piston would escape
at 6 into the air; at Figure 5 the steam would act on the lower face of the
piston, and that which had previously acted on its upper face will be put in
communication with the waste steam pipe. If the steam arrived by b, to
escape afterwards at a, the machine would move in an opposite direction to the
first motion, which is termed reversing action. I will now explain how it is
that the steam may enter alternately by a or by b. In Figure 6 a and b indicate
the notches or chambers of the key A; C and D are pipes which each
open

page_text: in one of the chambers a¹ and 61; one of these pipes will serve for the
introduction of the steam, whereas the other is intended for its escape. The
key remaining fixed the distribution of the steam will take place by the
oscillation of the cylinder, one of the orifices of distribution communicating,
for example, with the chamber a¹ will receive the steam from the boiler,
whereas the other will communicate with the chamber and the pipe D,
which is for the moment a waste pipe.
.
Secondly, reversing action.-The Figure 6 represents not only the method
of distribution, but also the manner in which the pipes C and D may be put
in communication the one with the atmosphere, the other with the boiler, and
how this arrangement may be changed at will by making D communicate
with the atmosphere and C with the boiler. At B is a cock with four open-
ings, in which are adjusted the pipes C, D, E, V. The cock is represented so
as to shew section of the seat and of the key, which is constructed like that
which enters the pivot or trunion of the cylinder. The pipe V communicates
with the boiler, and it is in this conduit that is placed an obturator governed
by the centrifugal force regulator. The pipe E serves for the waste, and the
pipes C and D go to the distributing apparatus. In this Figure the steam
arriving by V goes into the chamber 6, follows the pipe D, and gains the
chamber b, from whence it is alternately distributed on each of the faces of the
cylinder. The exit of the steam therefore takes place first by the chamber a,
then by the pipe C, the chamber a', and the pipe E. If now the key of the
cock B be turned in a contrary direction, as at Figure 7, the steam will
go from V into a', the pipe C, and the chamber a, to be distributed 'in the
cylinder, and the exit will take place by b, D, 6', and finally by E. For a machine
without reversing action, one of the pipes C or D would be fixed to the
boiler, and the other would go to the atmosphere, or into the condenser.
to the method of fixing the key in the trunion of the cylinder, a channel is
made through the key in the direction of its length, which channel will
contain a jointed rod, fixed by one part to the bottom and centre of the seat,
and the other part of which will extend outside the key and terminate in form
of serew car: ying a bolt to tighten the key in the seat. This key may enter
and come out to a certain extent, but should not turn on itself, and for this
purpose it will be held by two small ears or lugs placed on one side and the
other of the truncated cone, and guided by iron rods, which pass through them
and will be fixed to the frame of the machine (see Figure 8).
As
Double cylinder engines.-The cylinders may occupy various positions as
regards each other, but in all cases each machine will be constructed after the

page_text: manner above described; there will, however, be a steam cock common to
It
both, in which the pipes C and D will branch at C' and D', Figure 9.
is proposed to adapt to machines constructed according to this Invention a
feed pump, the barrel terminating in a cock, the extremity of the handle of
the key of which is jointed at right angles to the rod of a float contained in
the boiler, and placed at such a level that when the water rises too high the
float is lifted and its rod transmits the motion to the key of the cock, which
by means of a pipe brings back to the feeding tank the excess of water fur-
nished by the pump. If, on the contrary, the water level lowers in the boiler,
the float descends, the overflow cock closes, and the feeding is resumed. A
conical valve might be substituted in lieu of the cock.
The application of these improvements to fixed cylinder engines is as
follows:-
First process. The cylinder carries only one pivot, in which the dis-
tribution and the reversing must be effected, as in the case of an oscillating
cylinder. For this purpose the distributing cone C (Figure 10) carries a
lever arm a, jointed at 6 to a long rod B. This rod is provided with two
angle blocks a and b, against which the head of the piston P strikes before
the end of each journey. This meeting of the piston and the angle blocks
sets the distributing cone in motion. The reversing gear differs from that
described for the oscillating engines only in a modification of the position of
the tubes, which, instead of taking into the thickness of the cone, come together
in the pivot at a, b, (Figure 11), absolutely like the pipes c and d, which
serve for the distribution in the cylinder.
Second process. Same arrangement as in the preceding, excepting that
the cone is moved by an excentric fixed on the horizontal shaft.
Third process. The distributing cone carries two lugs a and b (Figure 12),
on each of which will be observed a strong pin projecting as shewn in profile
at a², b¹. A metal rod fits on the one part to an excentric carried by the
horizontal shaft, and on the other part to one or other of the pins, accordingly
as the engine is to work forward or backward. The cock with reversing
action is therefore suppressed, and the pivot receives two pipes a and b
(Figure 13), one of which goes to the boiler and the other directly to the
atmosphere. The following is the mechanism by which it will be easy to
cause the slide rod to act on one or the other of the pins a, b, so as to reverse
motion-The rod T (Figure 14) spreads out at D, and is pierced at A with
an orifice which permits the introduction of the pins a¹ and b. At P is a
handle which serves to move the rod T, and carry it on to one or other pin.

page_text: For that purpose the rod T is lengthened and penetrates into a handle M, in
which it may slide with gentle friction. A segment of a circle A¹ guides the
handle and prevents its participating in the movement of the rod. The
management of this part thus becomes more easy. Figure 15 represents a
section of the segment of a circle A', shewing a groove .in which slides the
handle M, without participating in the movements of the rod T. Two stops R
and R¹ permit the fixing of the slide rod on the one or the other of the pins of
the distributing cone, and to reverse the motion of the engine.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Gedge in the Great Seal Patent Office on
the 15th June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD GEDGE, of the Firm of John Gedge and Son, of No. 11, Wellington
Street, Strand, in the County of Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of December, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Edward Gedge, Her special licence that I, the said
William Edward Gedge, my executors, administrators, and assigns, or such
others as I, the said William Edward Gedge, my 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 Inven-
tion for "IMPROVEMENTS IN STEAM ENGINES," (a communication to me from
abroad by Arthur de Montméja, of 39, Faubourg St. Martin, Paris, France,)
upon the condition (amongst others) that I, the said William Edward Gedge,
my executors or administrators, by an instrument in writing under my, or their,
or 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.

page_text: NOW KNOW YE, that I, the said William Edward Gedge, do hereby
declare the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
The Invention consists in a new mode of distributing the steam, reversing
motion by apparatus independent of the engine, and the application of these
improvements to engines with fixed or with oscillating cylinders. The
engine is composed of an oscillating cylinder, in which moves a piston acting
directly on the horizontal shaft. This latter carries but one eccentric for
the feed pump, and one grooved pulley to receive the belt or band of the
regulator. The feed pump may also be worked by one of the pivots or
trunions, of the cylinder by means of a small lever arm perpendicular to
the trunion and which joins on to the end of the piston rod of the pump.
The entire modification bears on the distribution of the steam and the
reversing action.
Firstly, as to the distribution of the steam. The oscillating cylinder is
supported by two pivots or trunions, which are received in bearings in the
framing as in ordinary engines, excepting that they pass a little way beyond
these bearings; and further, one of them, more bulky than the other, is hollowed,
following its axis by a conical cavity, which may be compared to the seat of a
stop-cock. In this conical cavity, the base of which should be rather large
compared with its height, is received a key in form of a truncated cone. The
key and its seat are ground to fit exactly the one on the other. This latter, which
is nothing but the pivot of the cylinder, is pierced with two orifices diametri-
cally opposed to each other, and in which fits the tubes that are to conduct the
steam over or under the piston, supposing the machine to be vertical. They
give exit to the steam which has acted on this same piston. On the accom-
panying Sheet of Drawing forming part of this Specification, Figure 1 repre-
sents a section of this part. The key (as shewn Figure 2) is constructed like
that of an ordinary cock, in the middle of which two cuts or slots have been
made, separated by a full part, the length and the breadth of which are exactly
the same as that of the orifices of the seat. It will be at once understood that
the key being placed in the seat may take successively the several positions
shewn Figures 3, 4, and 5, in relation to the orifices with which the seat is
pierced. These Figures represent transverse sections, and consequently the
key is only represented by the full or solid part separating the two cuts or slots
before mentioned. This full space I term the diaphragm. Suppose the pipes
A communicating with the upper part of the cylinder, and those B with its

page_text: lower part; suppose, on the other hand, that all the points a are in communi-
cation with the boiler, and the points 6 with the atmosphere, what would be
the consequence? At Figure 3 the machine would be at dead point; at
Figure 4 the steam would act on the upper face of the piston, and that which
was beneath the piston would escape at 6 into the air; at Figure 5 the steam
would act on the lower face of the piston, and that which had previously acted
on its upper face will be put in communication with the waste steam pipe.
If the steam arrived by 6, to escape afterwards at a, the machine would move
in an opposite direction to the first motion, which is termed reversing action.
I will now explain how it is that the steam may enter alternately by a or by b.
In Figure 6 a and b indicate the notches or or chambers of the key. A, C, and
D, are pipes which each open in one of the chambers a' and '; one of these
pipes will serve for the introduction of the steam, whereas the other is intended
for its escape. The key remaining fixed, the distribution of the steam will
take place by the oscillation of the cylinder. One of the orifices of distribution
communicating, for example, with the chamber a' will receive the steam from
the boiler, whereas the other will communicate with the chamber and the
pipe D, which is for the moment a waste pipe.
Secondly, reversing action.-The Figure 6 represents not only the method
of distribution, but also the manner in which the pipes C and D may be put
in communication the one with the atmosphere, the other with the boiled, and
how this arrangement may be changed at will by making D communicate
with the atmosphere and C with the boiler. At B is a cock with four openings,
in which are adjusted the pipes C, D, E, V. The cock is represented so as
to shew section of the seat and of the key, which is constructed like that
which enters the pivot or trunion of the cylinder. The pipe V communicates
with the boiler, and it is in this conduit that is placed an obturator governed
by the centrifugal force regulator. The pipe E serves for the waste, and the
pipes C and D go to the distributing apparatus. In this Figure the steam
arriving by V goes into the chamber 6, follows the pipe D, and gains the
chamber b, from whence it is alternately distributed on each of the faces of
the cylinder. The exit of the steam therefore takes place first by the
chamber a, then by the pipe C, the chamber a', and the pipe E. If now the
key of the cock B be turned in a contrary direction, as at Figure 7, the steam
will go from V into a', the pipe C, and the chamber a, to be distributed in the
cylinder, and the exit will take place by b, D, b', and finally by E. For a
machine without reversing action, one of the pipes C or D would be fixed to
the boiler, and the other would go to the atmosphere or into the condenser.

page_text: As to the method of fixing the key in the trunion of the cylinder, a channel is
made through the key in the direction of its length, which channel will contain
a jointed rod fixed by one part to the bottom and centre of the seat, and the
other part of which will extend outside the key and terminate in form of screw,
carrying a bolt to tighten the key in the seat. This key may enter and coine
out to a certain extent, but should not turn on itself, and for this purpose it
will be held by two small ears or lugs placed on one side and the other of the
truncated cone, and guided by iron rods, which pass through them and will be
fixed to the frame of the machine (see Figure 8).
Double cylinder engines.-The cylinders may occupy various positions as
regards each other, but in all cases each machine will be constructed after the
manner above described; there will, however, be a steam cock common to
both, in which the pipes C and D will branch at C and D', Figure 9. It is
proposed to adapt to machines constructed according to this Invention a feed
pump, the barrel terminating in a cock, the extremity of the handle of the key
of which is jointed at right angles to the rod of a float contained in the boiler,
and placed at such a level that when the water runs too high the float is lifted
and its rod transmits the motion to the key of the cock, which by means of a
pipe brings back to the feeding tank the excess of water furnished by the
pump. If, on the contrary, the water level lowers in the boiler, the float
descends, the overflow cock closes, and the feeding is resumed. A conical
valve might be substituted in lieu of the cock.
.
The application of these improvements to fixed cylinder engines is as
follows:-
First process. The cylinder carries only one pivot, in which the dis-
tribution and the reversing motion must be effected, as in the case of an oscil-
lating cylinder. For this purpose the distributing cone C (Figure 10) carries
a lever arm a, jointed at b to a long rod B. This rod is provided with two
angle blocks a¹ and b', against which the head of the piston P strikes before
the end of each journey. This meeting of the piston and the angle blocks
sets the distributing cone in motion. The reversing gear differs from that
described for the oscillating engines only in a modification of the position of
the tubes, which, instead of taking into the thickness of the cone, come
together in the pivot at a, b, (Figure 11), absolutely like the pipes c and d,
which serve for the distribution in the cylinder.
Second process. Same arrangement as in the preceding, excepting that
the cone is moved by an excentric fixed on the horizontal shaft.
Third process. The distributing cone carries two lugs a and b (Figure 12),

page_text: on each of which will be observed a strong pin projecting as shewn in profile
at a', 6' (Figure 12*). A metal rod fits on the one part to an eccentric
carried by the horizontal shaft and on the other part to one or other of the
pins accordingly as the engine is to work forward or backward. The cock
with reversing action is therefore suppressed, and the pivot receives two
pipes a and b (Figure 13), one of which goes to the boiler and the other
directly to the atmosphere.
The following is the mechanism by which it will be easy to cause the slide
rod to act on one or the other of the pins a, b, so as to reverse motion :-The
rod T (Figure 14) spreads out at D, and is pierced at A with an orifice, which
permits the introduction of the pins a' and b. At P is a handle, which serves
to move the rod T, and carry it on to one or other pin. For that purpose the
rod T is lengthened, and penetrates into a handle M, in which it may slide
with gentle friction. A segment of a circle guides the handle, and prevents
its participating in the movement of the rod. The management of this part
thus becomes more casy. Figure 15 represents a section of the segment of a
circle A', shewing a groove in which slides the handle M, without participating
in the movements of the rod T. Two stops R and R' permit the fixing of
the slide rod on the one or the other of the pins of the distributing cone, and
to reverse the motion of the engine.
Variable expansion gear.-An arrangement of expansion gear forming part
of this Invention is shewn Figures 16 and 17, but preference is given to
that shewn Figure 18, of which the following is a description :-The variable
expansion is produced in this improved arrangement of steam engine by means
of a moveable cone penetrating into the fixed cone already described. These
two cones are concentric, and while having a common axis, their surfaces,
described by different generating points, are divergent towards the summit,
the effect of which arrangement is to establish compensations in tho wear of
the surfaces. T, T, indicates the pivot or trunion of the cylinder; P, P, con-
duits leading from it, to give alternately entrance and escape to the steani
which acts on the piston. The large fixed cone T', T, receives two pipes V
and E in its greatest thickness. The pipe V comes from the boiler, and that
E serves for the escape without the necessity of a special cock to change the
steam entrance and escape at will, as is the case in the machines without
expansion gear, and a reverse action will be obtained by means of the cone C,'
as hereafter described. The pipes V and E each end in a chamber V' and E'.
From the chamber V the steam passes into one of the chambers A or B, while
the escape will take place from the chambers B or A into the chambers E¹

page_text: and the pipe E. The communication between the chambers A and B and the
chambers V¹ and E¹ takes place by the orifices o and o¹ made in the side of the
hollow cone.
I now pass to the description of the cone C. This cone, of which the
diaphragm only is shewn in the section drawn, has for object to intercept
at a given moment the access of the steam to one of the chambers A or B,
so as to produce the expansion. It is evident that its action on the escape-
ment must be entirely nil, otherwise there would be counter-pressures and
loss of power, and to this end the diaphragm does not occupy the middle of
the cone and however great the oscillation of this latter, one of the orifices o
and o always communicates with the chamber E¹ and the pipe E. This same
diaphragm is pierced with two steam ports m and n, which have each the
same dimensions as the orifices o and o¹. Each of these steam ports divides a
corresponding extremity of the diaphragms in two parts a and b, then a¹ and b'.
The parts a and a¹ have the requisite thickness to obliterate or cover exactly
the openings o and o¹. The parts b and b¹ are of no special thickness, as they
fulfil no other office than that of preventing all communication between V¹
and E. In this Figure the steam arrives in the chamber A by passing through
the conduit m. If the cone moves in the direction of from V towards E at a
certain moment the solid part a will obliterate the opening o, and if the cone
moves further in the same direction the opening o will again find itself in
connection with the steam. If now the cone accomplishes but or this dis-
placement forward and backward, it will be understood that there is expansion
of the steam. If now by any sort of mechanism the orifice o¹ is put in
connection with the lower extremity of the diaphragm, the engine will work in
an opposite direction to the first, because the distribution will take place from
V¹ into B, B, and the escape from A, A, into E', the orifice o being withdrawn
from the action of the diaphragm. The mechanism by which the cone is
moved and the expansion gear regulated is as follows:-An eccentric A
(Figure 19), carried by the horizontal shaft, and making with the crank an
angle of 90%, governs a rod B, jointed at C. The rod C, C¹, is raised or
lowered in a slide bar G by means of a screw V.
bar are engraved the degrees of expansion, and a
rod C, C¹, indicates which of these degrees presides in the working of the
engine. The rod C, C¹, governs the come-and-go motion of the expansion
cone D by the aid of two rods T, T', which surmount this cone, one of which
corresponds to the forward and the other to the backward action. By a very
simple clickwork the head of the rod C, C', fixes itself to one or other of the
On the front of the slide
small cursor fixed to the

page_text: rods T, T. The screw V causing the rise and fall of the rod C, C¹, along T or
T, the variable expansion is produced at the desired degree.
In witness whereof, I, the said William Edward Gedge, have hereunto set
my hand and seal, this Fifteenth day of June, in the year of our Lord
One thousand eight hundred and sixty-five.
W. E. GEDGE. (LS.)