IMPROVEMENTS IN LOCOMOTIVE STEAM ENGINES
Year: 1857

page_text: LETTERS PATENT to Rudolph' Bodmer, of 2, Thavies Inn, Holborn, in
the City of London, for the Invention of "IMPROVEMENTS IN LOCOMOTIVE
STEAM ENGINES."-A communication.
PROVISIONAL SPECIFICATION left by the said Rudolph Bodmer at the
Office of the Commissioners of Patents, with his Petition, on the 18th
May 1857.
I, RUDOLPH BODMER, of 2, Thavies Inn, Holborn, in the City of London,
do hereby declare the nature of the said Invention for, "IMPROVEMENTS IN Loco-
MOTIVE STEAM ENGINES, (a communication from a foreigner residing abroad,) to
be as follows:-
My improvements have for their object to prevent the driving wheels of
locomotive engines from slipping when the train is being started. They con-1
sist in a throttle valve placed within the blast pipe, and which when the train
is to be set in motion is first completely closed, the steam admission valve
being thereupon fully opened. The throttle valve is then opened just to the
extent that is necessary to allow the train to move, and it is evident that
although the whole pressure of the steam is on the piston, the speed of the
wheels must be strictly proportionate to the quantity of steam which is allowed
to escape at the throttle valve. The spinning round of the wheels is therefore
completely prevented whatever may be the amount of friction between the
wheels and the rails.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Rudolph Bodmer in the Great Seal Patent Office on the 18th
November 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RUDOLPH
BODMER, of 2, Thavies Inn, Holborn, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of May, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Rudolph Bodmer, Her special licence that I, the said Rudolph Bodmer,
my executors, administrators, and assigns, or such others as I, the said
Rudolph Bodmer, 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 Invention for "IMPROVEMENTS IN
LOCOMOTIVE STEAM ENGINES," (a communication from a foreigner residing abroad,)
upon the condition (amongst others) that I, the said Rudolph Bodmer, 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 per-
formed, 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 Rudolph Bodmer, 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 (that is to say):-
This Invention consists in the application of a throttle valve or other
suitable valve in the exhaust pipe of locomotive steam engines, by means of
which valve the exhaust pipe can be either partially or wholly closed, con-
sequently the escape of the off-steam impeded or prevented, and by the less
or more powerful back pressure, thus produced, the speed of the driving wheels
checked or regulated at pleasure. The engine driver is by the use of this
valve enabled to prevent the wheels from spinning round on starting the train,
or in wet weather to moderate the velocity of the train in going down an
inclined plane, and even to stop the train altogether in a shorter time than
could be done by the application of the breaks.

page_text: In order that this Invention may be more clearly understood and readily
carried into effect, I will now proceed to describe the same, reference being
had to the annexed Sheets of Drawings, and to the letters and figures marked
thereon.
In Sheet 1, Fig. 1 is a front view, partly in section, and Fig. 2 a
longitudinal side elevation, in section, of parts of a locomotive engine boiler,
showing the exhaust pipe fitted with a throttle valve; Fig. 3 is an elevation,
partly in section, of a portion of the exhaust pipe and of the throttle valve
on an enlarged scale; and Fig. 4, a top view of the same.
That part of the exhaust pipe which is within the smoke box is composed
of two pieces A and B, which are screwed together by means of flanges A¹
and B' and bolts, the junction of these two pieces forming a spherical recess a,
in which the throttle valve C is lodged, the blast pipe D being constructed
as usual with an adjustable regulator. The throttle valve C is fixed upon
the spindle 1 by means of a key, and fits into the spherical recess a.
A pro-
longation 1 of the spindle 1 projects beyond the flanges A¹ & B¹, passes,
through the side of the smoke box, and is there fitted with a lever 2 (see Fig. 1),
to which is hinged a rod 3, which is brought within reach of the engine driver,
and which must be fitted with a lever or handle, and so arranged that it
can be fixed. in various positions, somewhat like the lever by which the
position of the slide valves is regulated. The outer bearing for the spindle 1°
is attached to the smoke box, whilst the two inner ones, which immediately
support the throttle valve, are formed by the flanges A¹ and B¹, and must be a
steam-tight fit. It is scarcely necessary to say that the position of the throttle
valve in the exhaust pipe must be adapted to the peculiar construction of the
latter.
When the train is to be started the apparatus is applied in the following
manner: Previously to opening the regulator the throttle valve is closed, so
that on the regulator being opened the full pressure of the steam may act upon
the pistons without permitting the wheels to acquire a greater velocity than
that which the position of the throttle valve admits of. The throttle. valve is
now gradually opened, until at last, when it is fully open, the train has
acquired its proper uniform speed. In wet weather, when the rails are
slippery, or under any other circumstances calculated to facilitate the slipping
or spinning round of the wheels, the escape of the steam through the exhaust
pipe is so far checked by the throttle valve that the wheels are prevented
from moving at a greater rate than that with which the train itself can be
propelled.
It is evident, that as the velocity of the driving wheels can be regulated to

page_text: the greatest nicety by the use of the throttle valve, this apparatus can be
applied to great advantage in going down, an incline, for the purpose o of
moderating the speed of the train without using, the breaks. In a similar
manner also, and without having recourse to the regulator, the train can be
stopped more or less .suddenly. by means of the throttle valve, and that with
more safety. than by. the application of the break; and as the wheels continue
to rotate until the train: comes; to, a, stand still, which is, often not the case
when the break is used, the wheels cannot be subjected to that kind of wear
and tear which produces flat surfaces on them.
As the heavily-loaded driving wheels of locomotive engines must necessarily
produce a three or four-fold effect as compared with the waggon wheels when
locked by, the break, it is evident that by means of this throttle valve, especially
on inclined planes, the wear and tear on the driving wheels is considerably
reduced, and greater safety, effected, owing to the greater facility and efficiency
it presents for stopping the train.
In Sheet 2, .Fig. 1 is a. sectional elevation, and Fig. 2; a ground plan,
partly in section, of; an exhaust, pipe fitted with another kind of valve,, which
may. be used instead of the throttle valve previously described, for effecting
the same purpose.
It is also applicable as a blast pipe regulator.
In this case the exhaust steam is supposed to arrive by the pipe or branch A
(shown in dotted lines), and to pass through the aperture A¹ between the
piston B and the conical valve C, the former being a good but easy fit in the
tube D. The .cone C and piston. B are connected together, by the rod 1,
which is in its turn, by, means of the bell-crank lever 2, 2º, connected with the
nut 3, and as the steam is admitted, between the piston B and conical valve
C the pressure upon the latter is thus neutralized. One end 4ª of the shaft 4
is screwed into the nut 3, whilst the other end 4b, which is furnished with a
screw thread cut in the opposite direction, takes into the stationary nut 5; so
that by turning the handle 6 in one direction the conical valve C can be
depressed or opened to admit of the escape of the steam to the extent shown,
in dotted lines, whilst by turning the handle 6 in the opposite direction the
conical valve C can be raised until its upper surface, a comes in contact with
the conical part 6 of the mouthpiece E, when the escape. of the steam is.
entirely cut off. The opening through which the shaft or spindle 7, on which
the bell-crank lever 2, 23, is fixed, passes, is made, steam-tight by means of a.
cone in the cap 8, and the spindle 7 reaches from the middle of the boiler
over the width of the fire box in order to, admit of the shaft 4 running
parallel with the boiler. By means of bolts 9 passing through the lugs 10.
(see Fig. 2), the mouthpiece. E is fixed to the tube D'. It will be seen that

page_text: the cone C is guided by four wings or diaphragms c, and that it may also
be made to perform the functions of a regulating valve for the blast pipe.
Having now described the nature of the improvements which have been
communicated to me, and the manner in which the same are or may be
carried into effect, I wish it to be understood that I do not mean to confine
myself to the particular construction of valves berein-before described; but
what I claim as the Invention intended to be secured to me by the above in
part recited Letters Patent is, the regulating the speed of the driving wheels
of locomotive steam engines by impeding or altogether preventing the escape
of the off-steam by means of a throttle valve or other convenient valve applied
in the exhaust pipe.
In witness whereof, I, the said Rudolph Bodmer, have hereunto set
my hand and seal, this Eighteenth day of November, in the year of
our Lord One thousand eight hundred and fifty-seven.
RUDOLPH BODMER. (L.S.)