IMPROVEMENTS IN LOCOMOTIVE ENGINES
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by Edward Slaughter at the Office of
the Commissioners of Patents, with his Petition, on the 19th January
1867.
I, EDWARD SLAUGHTER, of the Avonside Engine Company, Limited, St.
Philips, Bristol, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN LOCOMOTIVE ENGINES," to be as follows:-
This Invention has for its object improvements in locomotive engines, and is
applicable, firstly, to that class of locomotive engine called bogie engines; this
class of engine does not differ, so far as the driven wheels are concerned, from
the ordinary locomotive engine, which has one or more pairs of wheels made.
tractive by their direct connection with the cylinders, or by means of coupling.
rods; but for the purpose of facilitating their working on very curved lines
their carrying axles and wheels (which are generally though not always placed
at the front end) are disposed in a separate frame, called a bogie frame, so
arranged as to allow the axle or axles to point to the centre of the curve in
which the locomotive is travelling. Hitherto the wheels of the bogie have
not been made trractive, but have been used simply to carry a certain portion
of the weight of the engine.
My Invention has for its object to make the weight carried by the bogie
tractive by the addition of one or more steam cylinders, and the usual
appliances constituting a perfectly independent engine attached to the bogie
frame. I intend that steam shall be supplied to the bogie engine from the
same boiler which supplies the locomotive proper; the boiler must therefore

page_text: be proportioned for the supply of steam not only to the cylinders of the
main engine, but to those of the bogie engines; also with the object of making
the entire compound locomotive tractive, at the same time that the chief
object for which the bogie system is adopted, viz., the facilitating the working
round curves of small radius is preserved. I desire it to be understood that
by my Invention it is not at all necessary that the wheels of the bogie shall
be of the same diameter as those of the locomotive proper, on the contrary,
I assume that they would be of a different and smaller diameter, but I do
intend that the number of revolutions of the wheels of the bogie, and therefore
the reciprocations of the pistons of the bogie engines shall be so proportioned
as that the peripheries of the bogie and main engine wheels shall be made to
pass over the rails at the same speed, or as nearly as may be possible in
practice without other connection between them than the rails themselves. As
the bogie engine is only connected with the main boiler and engine framing by
a central pin or a moving plate or bearer, it is clear that the steam and exhaust
pipes attached to the bogie engine cylinders must be furnished with such articula-
tions; ball and socket, or universal joints, radial stuffing boxes, or other systems
known to practical men, as may be best adapted to make a perfectly steam-
tight connection; or connecting pipes may be used of such a length and
formed with a sufficient number of bends as to permit of their being employed
without the above enumerated systems of jointing; but I prefer to employ for
the steam connections perfectly designed pipes furnished with simple or radial
stuffing boxes or elongating or other joint pipes. For the exhaust pipes, which
I intend should be led into the chimney of the main engine to assist in blowing
the fire more simple universal jointing may be used. Whenever it may be
desired to produce a very powerful locomotive bogie engine, and yet to limit both
the weight carried upon any one axle, and possibly to limit the total weight of
the engine per foot run of railway occupied, say, from buffer to buffer, in
reference to the strength of bridges, works of art, or any governmental require-
ments, it is manifest that a great length of wheel base would be imperative;
but a great length of wheel base is not admissible where the curves of a
railway are sharp.
My Invention has for its object to permit of any required length of wheel
base, for bogie engines may be placed at either or both ends of the engine
proper, and the driving and coupled wheels of the engine proper may be
either four, six, or eight in number, and disposed as close to each other as
their diameters may permit. Such engines as those supposed may carry their
own water and fuel, and make tractive the weight of such water and fuel so
long as it exists, or they may be supplied with tenders in the ordinary way.

page_text: It will be clear to practical men that the dispositions of the wheels of
bogie engines may be such as that each axle whether of the main engine or
the bogie engine may carry an equal or nearly equal weight, and that in the
case of tank engines the tanks and fuel boxes may be so disposed in reference
to the axles of the main or bogie engines, and so connected together as that
the consumption of the water and fuel may diminish the weight over such
axles equally, or with a near approach to equality. I am quite aware that
other systems of compound and articulated locomotive engines have been
invented, having for their object to make the whole weight tractive, and to
pass round sharp curves; these have consisted mostly of two separate engines
joined together either by the boiler itself or by a frame containing the boiler
resting upon axles, but the peculiarity of this part of my Invention consists in
retaining the ordinary locomotive with its boiler and driving wheels, and
employing in addition the ordinary begie made tractive by the addition of a
steam engine to it. If desired the distribution of steam may be made to both
the main and the bogie engines from one regulator valve, and the starting and
reversing gear of both engines in spite of the movement of the bogie engine
frame may be so connected as that the combined engines may be worked and
treated as one engine. Locomotive engines have in some cases been here-
tofore constructed with what are known as radial axle boxes by which a pair
of wheels with its axle fitted with radial axle boxes, and carrying a certain
portion of the weight of the locomotive engine is compelled to point to the
centre of the curve of a railway over which it is travelling, and thus the
working of a locomotive engine round sharp curves is greatly facilitated.
According to my Invention I make tractive that portion of the weight of
a locomotive engine resting upon such radiating axles, for which purpose I
adapt to them a frame containing one or more steam cylinders with all
proper appliances to constitute a separate engine. I connect this engine by
its steam pipe with the boiler of the main engine at the central point from
which the curve of the axle boxes with their guides is struck, and at which
point consequently there is simply an almost imperceptible reciprocating hori-
zontal motion. I provide for this horizontal motion by a stuffing box of the
ordinary character, and I convey the exhaust steam from the cylinder to
the chimney by a simple pipe, which may or may not be furnished with
articulated jointings. It may not always be convenient to take the steam
from the main boiler at the central point from which the curve of the axle
boxes is struck; where this is so it would be necessary to adopt radial stuffing
boxes for the steam, and exhaust connections or elongating pipes, as set forth
in the description of my tractive bogie engine.

page_text: I wish it to be further understood that I do not confine myself to the
employment of one auxiliary radial engine in connection with the main loco-
motive engine, but I claim to employ if desired one such engine at either or
both ends of the main locomotive engine.
According to another arrangement I carry the locomotive boiler on a frame
which rests (by means of moveable bearing points) on two other frames, and
each end of the boiler frame is jointed to the end of the moving frame below
it; the moving frames are supported on two or more pair of wheels, and carry
an engine for making some or all of these wheels tractive; the cylinders of
these engines are placed at the end of each frame, where it is jointed to the
boiler frame, and the steam to supply the cylinders is by preference led
through the pivots or joints upon which the frame turns. The boiler I prefer
to construct in the form of two ordinary locomotive boilers placed end to end,
the fire-box being in the centre, and fed from the side, an ordinary boiler may
however be employed, and in place of employing two frames, such as above
described, pivotted one to either end of the boiler frame, one frame only
pivotted to one end of the boiler frame may be employed. In this case one or
more pair of wheels will be placed at the other end of the boiler frame. By
the arrangement above described the admission of steam to the cylinders
carried by the moving frames is simplified by reason of both the joints upon
which the frame turns and the steam cylinders of the engine being at one and
the same end of the moving frame, in place of the joint being in the contro
and the cylinders at one end as heretofore.