Improvements in Locomotives.
Year: 1893

page_text: Cate of Application, 6th Oct., 1893-Accepted, 11th Nov., 1893
COMPLETE SPECIFICATION.
Improvements in Locomotives.
I, CHRISTIAN ERDBRINK, of 7, Ifflandstrasse, Hanover, in the Empire of
Germany, Government Architect, 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 locomotives the exhaust steam is generally exhausted through a joint blast
pipe and serves as is well known to increase the draught. Attempts have been
made to adapt a division tongue or midfeather in the joint blast-pipe nozzle and
thus separate from each other the exhaust steam of the two pistons so as to prevent
the exhaust steain exerting a back pressure upon the said pistons.
Heretofore the fact has not been recognised that to obviate the defects which
result in the joint introduction of the exhaust steam of both cylinders into one blast
nozzle and that to attain as good a draught as possible it is not only necessary to
separate the two exhaust pipes completely from each other, but also to give the
same a certain relative position which is the only way of obviating the said defects
hereinafter more particularly detailed.
The present joint blast pipe arrangement causes chiefly the exhaust steam of one
cylinder to exert a back pressure upon the piston of the other cylinder when at its
full speed (middle position) which greatly reduces the useful effect of the latter
cylinder; this joint exit of the exhaust steam from the two cylinders causes also a
jerk upon the fire which is very injurious and heretofore unavoidable.
Heretofore the exhaust steam on its exit from the joint blast pipe had a very
large area on the locomotive working at a full charge, the moment the slide valve
had opened the exhaust channel and owing to the density of the jet tore with it
temporarily the combustible gases. This caused the combustible air in the furnace
to be drawn through rapidly and thus an imperfect combustion. The large orifice
of the blast pipe which caused the said sudden exit of the exhaust steam in a dense
jet, has heretofore been necessary to prevent a too great injurious back pressure of
the exhaust steam upon both the pistons.
In this invention, through the concentric arrangement of the two blast pipe
orifices, the inner of which has a circular section and the outer a ring like section,
the exhaust steam of both cylinders have their exit separate from each other and
each of the orifices through which the exhaust steam of each cylinder passes
separate from the exhaust steam of the other may naturally be formed smaller than
the joint nozzle heretofore in use for the exhaust steam; the steam jet on its
exit is therefore of a comparatively smaller section and can therefore not act
tearingly and thus injurious to the fire upon the bars. The exhaust steam of one
cylinder in no way affects the power of the piston of the other cylinder and the
delay caused in the exit of the exhaust steain resulting from the contracted exit
nozzle is yet useful for giving off work on its own piston, as the same is still on its
The concentric
outward stroke at the commencement of the exhaustion of steam.
arrangement of the two nozzles insures also the central exit of each steam jet in
the middle of the chimney, which is absolutely necessary for the creation of a good
draught.
The advantages which these contracted separate exit orifices for each exhaustion
of steam offer in respect of a better production of steam, must also not be
underated.
The tearing action upon the fire being reduced by the smaller sections of the
separated nozzles, a uniform draught through the fire bars is attained and thus a
better utilization of air and better combustion. Through the reduced section of
the separated nozzle an increased velocity of the exit of the exhaust steam is

page_text: obtained which increases the draught. This reduced section of nozzle also renders
the steam more compact; the chimney is not so readily filled with the expanding
steam and the exhaust steam remains thus longer in contact with the gases from
the furnace surrounding it, is heated by the same and has its water property
diminished which in combination with the reduced tearing action prevents the so
called "
"spitting."
And in order that my invention may be more fully understood I have caused to
be appended hereunto one sheet of drawings marked with letters of reference
indicating like parts in the various figures.
Fig. 1 is a plan in section and Fig. 2 a vertical cross section of my improvements.
a is the pipe for the exhaust steam of the left hand cylinder, the pipe for the
exhaust steam of the right hand cylinder of the locomotive. Both pipes are joined
by a corner piece consisting of two pipes c, d, one inserted into the other, whereby
an inner circular exit orifice o and an outer ring like exit orifice o' is formed.
Through these two orifices o, o', the exhaust steam leaves the left and the right
hand cylinders and are in proportion smaller in section than that of the joint blast
pipe heretofore in use, whereby the better result is as hereinbefore described.
This device is not only applicable for ordinary locomotives, i.e. for such in which
each cylinder is fed directly with steam at boiler pressure but also for compound
locomotives which permit of feeding the high pressure cylinder as well as the two
cylinders with steam at boiler pressure. In such compound locomotives the exhaust
pipe of the large cylinder is carried to the ring like blast pipe orifice o' and the
exhaust pipe of the high pressure cylinder is connected to the inner orifice o by
means of the outlet pipe b, so that on feeding the high pressure and low pressure
cylinder with steam at boiler pressure, the exhaust steam of the high pressure
cylinder has its exit direct through the pipe 6 and the orifice o and the exhaust
steam of the large cylinder through the pipe a and the ring like orifice o'.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is―
"In locomotives."
1st. The employment of two separate blast pipes the orifices of which surround
each other and receive the exhaust steam from each cylinder separately, substan-
tially as and for the purpose set forth.
2nd. The employment of two separate blast pipes the orifices of which surround
each other and receive the exhaust steam from each cylinder separately in such a
manner that the exhaust steam of the one cylinder enters the chimney through a
ring like orifice and that of the other through a circular orifice, substantially as
and for the purpose set forth.
3rd. A joint nozzle for two blast pipes consisting of two pipes b & c one inserted
into the other, the pipe c of which surrounds the pipe bring like, substantially as
and for the purpose set forth.
Dated this 5th day of October 1893.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.