Year: 1894

page_text: Date of Application, 3rd July, 1894
Complete Specification Left, 3rd Apr., 1895-Accepted, 29th June, 1895
A communication from K. LAUSMANN, Engineer, of Jurjew, Dorpat, Russia.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improved reversing gear for steam engines, gas-motors,
water-motors and other machines; and more particularly applicable to those
whereof the steam distribution is operated by valves or revolving discs.
If for example the valve distribution of a steam engine be considered whereof
the valves are operated by cam-discs or eccentrics rotated by a shaft which. is
itself rotated and reversed by bevel-gear driven by the main shaft, it is obvious
that the motion of the engine will be reversed if the driving bevel wheels engage
with the driven wheel at 180 degrees of the circumference apart; care being taken
however that the direction of rotation of the shaft operating the slide-valves shall
remain the same notwithstanding the reversal of the cam or eccentric shaft. If
moreover with this reversing gear, it is necessary to provide for the lap and lead in
the steam admission, the interval of engagement with the driven bevel-wheel,
between the two drivers must not be arranged at precisely 180° apart, but the
angular opening corresponding to the lead must be taken into account.
The same holds good for a rotary slide-valve. In this case if the change in the
point of engagement be made, in a similar manner, as between the main shaft and
the shaft of the rotary valve, while the latter is permitted to continue its rotation
in the same direction, the motion of the engine will be reversed.
A construction of the reversing gear which will accomplish the purpose in view
is as follows;-
On the cam or eccentric shaft two bevel wheels are so mounted as to rotate
loosely on the shaft but cannot move in the direction of its longitudinal axis. Both
these toothed wheels are constantly engaged with an intermediate toothed bevel
wheel conveniently keyed to the shaft on which it is mounted. This latter shaft
drives the rotary slide-valve directly or the distribution mechanism of the steam
cylinder etc. by means of suitable intermediate organs or parts. On the eccentric
shaft between the two loose toothed wheels is secured a coupling clutch which
while revolving with said shaft can be shifted to and fro in the longitudinal
direction of the shaft by means of a fork. The clutch is fitted with a projection
or stud at either end which in relation to each other's position circumferentially
occupy positions on opposite sides forming the necessary angular interval, say for
instance 180°. In the boss of each of the first-named toothed wheels a notch or
recess is formed, with which the clutch stud or projection is adapted to engage.
When the clutch is shifted over so as to bring one of the projections into engage-
ment with the corresponding notch or recess of one of the toothed wheels the said
wheel must then rotate with the shaft, whence it follows that the valve operating
shaft is rotated in one direction. If on the other hand the clutch sleeve be shifted
over so that the projection is withdrawn from the recess or notch then the valve
operating shaft momentarily ceases rotation. But if the movement of the clutch
PQ27
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page_text: .
be continued, the other projection is brought into engagement with the recess or
notch in the second toothed wheel, whereupon the engine is reversed, for the
distribution organs or parts are thus, by reason of the opposite positions of the two
projections on the coupling clutch brought into the reversing position in relation
to the crank on the main shaft which will then rotate in the opposite direction,
while the direction of rotation of the three wheels remains as before. Hence it
will be seen that the rotation of the valve operating shaft remains unchanged in
direction notwithstanding the reversal of the crank shaft. '.
The distribution organs which are actuated by the valve operating shaft
consequently operate in exactly the same way as before only that the crank is in
the opposite position in relation to them so that though unchanged in their action
they nevertheless reverse the working of the engine.
This reversing gear may be used with all kinds of distribution mechanism that
is driven by the valve operating shaft namely it is particularly adapted for use
with rotary slide valves and distribution valves, in steam and gas motors but it may
also be applied to hydraulic engines etc.
It may be remarked further that it is not necessary that the clutch studs or
projections should be placed in opposite positions to each other circumferentially
inasmuch as it is possible to regulate the amount or extent of reversal by an
adjustment of the engagement of the teeth of the wheels on the main shaft
relatively with those of the wheel on the valve operating shaft or otherwise by the
mounting of the machine.
Dated this 3rd day of July 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
Improvements in or relating to Reversing Gear for Steam and
other Motors.
A communication from KARL LAUSMANN, Engineer, of Jurjew, Dorpat, Russia.
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
Chartered Patent Agent, 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 improved reversing-gear for steam engines, gas-motors,
water-motors and other machines; and more particularly applicable to those whereof
the steam-distribution is operated by valves or revolving discs.
If, for example, the valve-distribution of a steam-engine be considered, whereof
the valves are operated by cam-discs or eccentrics rotated by a shaft which is itself
rotated and reversed by bevel-gear driven by the main-shaft, it is obvious that the
motion of the engine will be reversed if the driving bevel-wheels engage with the
driven wheel at 180 degrees of the circumference apart; care being taken, however,
that the direction of rotation of the shaft operating the slide-valves shall remain
the same notwithstanding the reversal of the cam- or eccentric-shaft. If, moreover,
with this reversing-gear, it is necessary to provide for the lap and lead in the steam
admission, the interval of engagement with the driven bevel-wheel, between the two
drivers must not be arranged at precisely 180° apart, but the angular opening
corresponding to the lead must be taken into account:
The same holds good for a rotary slide-valve. In this case, if the change in the
point of engagement be made, in a similar manner, as between the main shaft and
the shaft of the rotary valve, while, the latter is permitted to continue its rotation
in the same direction, the motion of the engine will be reversed.

page_text: A construction of the reversing-gear which will¨accomplish the purpose in view
is shown in the accompanying drawing.
On the cam or eccentric-shaft L the two bevel-wheels Z' and Z' are so mounted
as to rotate loosely thereon but cannot move in the direction of its longitudinal
axis. Both these toothed wheels are constantly engaged with an intermediate
toothed bevel wheel Z' keyed to the shaft a. This latter shaft a drives the rotary
slide-valve directly, or the distribution-mechanism of the steam cylinder, etc., by
means of suitable intermediate organs or parts. On the shaft L between the
two loose toothed wheels Z. Z is secured a coupling clutch which, while
revolving with said shaft L, can be shifted to and fro in the longitudinal direction
thereof by means of a fork g. The clutch k is fitted with a projection or stud n at
either end which, in relation to each other's position circumferentially, occupy
positions on opposite sides forming the necessary angular interval, say, for
instance 180°. In the boss of each toothed-wheel Z' and Z a notch or recess is
formed (as shown in dotted lines on the drawing) with which the corresponding
stud or projection n is adapted to engage.
When the clutch k is shifted over by
means of the fork g so as to bring one of the projections n into engagement with
the corresponding notch or recess of one of the toothed wheels Z¹ or Z', the said
wheel must then rotate with the shaft L; thus if the clutch be moved to the right,
as shown in the drawing, 71 and L will rotate together say in the direction
indicated by the arrow on the wheel Z'; whence it follows that Z' and a will
rotate in the direction indicated by the arrow on Z while Z runs loose on the
shaft L, driven by Z³ in the direction indicated by the arrow shown thereon in the
drawing. If, on the other hand, the clutch & be shifted over to the left, so that
the projection n is withdrawn from the recess or notch in Z', then the wheel Z' and
shaft a momentarily cease rotation. But if the movement of the clutch to the
left be continued, the other projection n is brought into engagement with the recess
or notch in the wheel Z3, whereupon the engine is reversed, for the distribution-
organs or parts are thus, by reason of the opposite positions of the two projections n
on the coupling-clutch k, brought into the reversing position, in relation to the
crank on the inain-shaft L. The main-shaft L will then rotate in the opposite
direction as indicated by the arrows in dotted lines on the drawing; while the
direction of rotation of the three wheels Z' Z Z³ remains as before, only now Z
becomes the driving wheel, while Z' is driven loose upon shaft L by means of Z³.
Hence it will be seen that the rotation of shaft a remains unchanged in direction,
notwithstanding the reversal of the crank-shaft L.
The distribution organs which are actuated by the valve-operating shaft a
consequently operate in exactly the same way as before, only that the crank is in.
the opposite position, in relation to them, so that, though unchanged in their action,
they nevertheless reverse the working of the engine.
This reversing-gear may be used with all kinds of distribution-mechanism that
is driven by the shaft a; namely, it is particularly adapted for use with rotary and
other distribution valves, in steam and gas motors, but it may also be applied to
hydraulic engines, etc.
It may be remarked, further, that it is not necessary that the clutch studs or
projections should be placed in opposite positions to each other, circumferentially,
inasmuch as it is possible to regulate the amount or extent of reversal by an
adjustment of the engagement of the teeth of the wheels Z' Z, relatively, with
those of the wheel Z3, or, otherwise, by the mounting of the machine.
Having now particularly described and ascertained the nature of the invention,
as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is ;-
1. Valve-gear for fluid pressure engines characterised by a valve-driving shaft
in such operative connection with the main shaft of the engine that it will rotate
only in one direction whether the engine be running forward or backward and that

page_text: its. setting is angularly adjustable in relation to the crank shaft substantially as
described.
2. In valve gear such as described in Claim 1 a countershaft (a) geared by means
of a bevel toothed wheel (Z') with a pair of bevel-wheels (Z' and Z') running
loose on the crank-shaft (L), and capable of being alternately coupled with the
said crank-shaft (L) by means of a clutch such as (k) substantially as described
and illustrated in the accompanying drawings.
Deted this 3rd day of April 1895...
W. P. THOMPSON & BOULT
Agents for the Applicant.