Reversing or Controlling the Direction of Motion of Engines.
Year: 1887

page_text: Reversing or Controlling the Direction of Motion of Engines.
**pparatus for Stopping and
I WILLIAM ALLAN of Scotland House Sunderland in the county of Durham,
Engineer 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:-
This invention relates to a certain new or improved means of and apparatus for
stopping and reversing or controlling the direction of motion of engines and is
applicable to many kinds of engines but more particularly so to engines of the
inverted or horizontal direct acting type such for example as Marine Engines.
The object of the invention is to provide a ready method of reversing engines in
motion by a single manual action and without the necessity of shutting off steam,
and also to simplify construction by dispensing with the use of one of the pair of
excentrics and link motion, drag and other rods generally necessitated by the usual
construction of engines.
In order to accomplish my object I provide a supplementary shaft or sleeve upon
which for each cylinder and its slide valve one excentric sheave is keyed and
connected in the usual manner with the slide valve. This supplementary shaft or
sleeve is driven by suitable gear and connections direct from the main engine and a
lifferential gear is provided whereby the shaft or sleeve may be moved so as to alter
he angle of the excentric sheave in relation to the crank and thereby stop or reverse
he action of the slide valve and consequently the direction of motion of the engine.
[Price 8d.1

page_text: I will now fully describe my invention referring in so doing to the accompanying
drawings which chiefly represent the invention as applied to a triple expansion marine
engine, but it is obvious that it is equally applicable to other kinds of engines the.
number of cylinders being immaterial and one such application is illustrated in
figure 5.
5
Figure 1 is a front elevation showing the general arrangement of main driving and
supplementary excentric shafts with differential gear. Figure 2 is an end elevation,
the said gear being shown in elevation on line y.. figure 1. Figure 3 is a sectional
elevation through differential gear. Figure 4 is a sectional plan of same showing
supplementary and driving shafts and mode of connection. Figure 5 is a partly 1
sectional view of another arrangement of my invention. Similar letters refer to
similar parts in all of these figures.
C
a is a supplementary shaft carried in bearings, affixed to the columns or cylinder
supports on which the excentrics a¹a' a' are keyed and connected in the usual manner
to the cylinder slide valves, on the fore end of shaft a, a bevel wheel is keyed. In 1
line with shaft a a short length of shaft is suitably mounted, one end of which is
dowelled into and rests in the shaft a. Upon the shaft c a bevel wheel corre-
sponding to but at a suitable distance from is keyed. Between these two bevel
wheels a combined sector and pinion carrier dis slung free to rotate on the
shaft c.
On one side of the boss of the combined sector and pinion carrier the
an arm or arms carrying
toothed sector is formed, on either side of which projects
a pinion or pinions e which gears or gear with the bevel wheels bb. The toothed
sector gears with the worm which is carried in suitable bearings and provided
with a hand wheel / actuating same or it may be actuated by steam: The shaft c may
be driven as shown direct from the main engine crankshafts by securing to the end
or coupling flange of the latter a flange with double crank pin gly, that is, a steel
casting or forging having a crank ping to which another or outside crank pin
depends. These pins are placed at right angles to one another to prevent dead
centreing and may have any suitable throw.
On the driving shaft e a similar double crank pin c c is fixed the crank pins e¹¹
and are connected together by suitable rods; or the shaft c may be driven by
means of gear or levers attached to and worked by the main engine connecting rod
gudgeons, in this case the supplementary shaft would be hollow with the driving pins
at each end.
C
The action is as follows:-On the revolution of the main engine crank shafts the
shaft c is rotated by the connections c¹², y¹², and rods as described or other suitable
means, and its bevel wheel driving the pinion or pinions e e gives motion to the
excentric or supplementary shaft a.
By turning the hand wheel h and worm ƒ a corresponding alteration is made in th
Hence it follows that the angles of the excentri
pinions e e and excentric shaft a.
sheaves in relation to the crank will also be altered and the engine stopped or reverse
as described by the simple motion of the hand wheel 1, and by the use of one excentri
only to each slide valve.
go
ahead
It will be apparent that when the pinions e e are geared to suit say the "
position for excentrics, their being shifted to the opposite angle makes them drivers
the excentric shaft bevel wheel itself and consequently the excentric shaft is move
accordingly.
An arrangement of my invention which presents considerable advantages und
certain circumstances is shown in figure 5. In this arrangement in which o
cylinder and one excentric only are shown, the excentric a' is mounted on a sleeve
The bevel wheel is fixed to the sleeve a a
which is loose upon the crankshaft s.
the bevel wheel is keyed upon the crank shaft s, the differential gear is arranged
before described and by the motion of the wheel and worm the sleeve a and excentric
may be moved to the required angle in relation to the crank.

page_text: Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
1. The arrangement for operating a slide valve of an engino consisting of an
excentric mounted upon a supplementary shaft or sleeve which is driven through
interposed gearing such as hereinbefore described so that by varying the position of
an intermediate wheel the position of the excentric in relation to the crank may be
varied substantially as herein before described.
2. The arrangement of the excentric in combination with the wheels band and
pinion e suitably mounted substantially as and for the purposes hereinbefore described.
3. The several arrangements of my improved apparatus shown respectively in
figures 1 to 4 and figure 5.