Year: 1886

page_text: Date of Application, 6th Dec., 1886.
Complete Left, 6th Sept., 1887.
Complete Accepted, 7th Oct., 1887
We SYLVANUS EDDINGTON, and JOHN EVAN STEEVENSON, both of Chelmsford, in
the County of Essex, Engineers, do hereby declare the nature of this invention to
be as follows:-
Our improvements in traction or road locomotive engines relate to the change gear
for varying the speed at which the engine travels; to the introduction of springs
into the gear for preventing breakage of the teeth of the wheels, and to means for
preventing the uncovering of the crown of the fire-box when the engine is on an
incline, and of preventing priming.
The first improvement has for its object. to simplify the construction of the
change-gear, save weight, and lessen the width occupied by the gear so as to
enable the engine to be made narrower than usual; and it consists in a con-
struction and arrangement of the change gear whereby the second motion wheel is
made movable in its own plane towards and from the crank-shaft for the purpose
of being geared with either of two pinions of different diameters thereon, the
arrangement being such that when the second motion wheel is in gear with either
of those pinions, the second motion pinion will also be in gear with the wheel
on the driving wheel axle.
.
The second improvement consists in the construction of a gear wheel with a loose
toothed rim, and in the introduction of springs acting in a circumferential direction
between said rim and the boss of the wheel whereby limited independent circum-
ferential motion of the rim is permitted and shocks due to back lash or over
running liable to break the teeth of the gear, are deadened.

page_text: ine third improvement consists of a division plate in the barrel of the boiler
extending from the front for such a distance towards the fire-box of the boiler as
to limit the water-space at the front end so as to prevent the level rising beyond
a certain height above the tubes at that end, thus preventing the water leaving
the crown of the fire-box wholly uncovered when the front of the engine is on a
lower level than the firebox end.
The slow-speed pinion is keyed on the crank shaft, and the fast-speed pinion is
preferably fitted to slide on the boss of the slow-speed pinion (or
the shaft itself) with a groove and feather connection.
might be on
The fast-speed pinion is cupped, and is so much larger than the other pinion,
that when it is to be thrown into gear, it can ho slid over the same so as to
bring its toothed rim into the same plane therewith, the sliding motion being
effected by a forked lever embracing the grooved boss of the pinion, as well
understood.
Or, instead of the larger pinion being cupped, it might be of the ordinary form,
the two pinions in that case sliding together on the crank shaft with a key-way
connection between the double pinion and the shaft. The second motion wheel and
pinion rotate together, and are movable in their own plane towards or from the
-crank shaft, so that they can be shifted in position as required, to allow for the
difference of diameter of the fast and slow-speed pinions.
The preferred mode of making the second motion wheel and pinion movable as
above mentioned, is by mounting said wheel and pinion to turn loose upon an
eccentric boss on the overhanging end of the second motion shaft and by making the
shaft rotate to a limited extent in its bearings, the shaft being locked in either of its
two positions, the radius of eccentricity of the boss being such that the necessary
change of position of second motion wheel will be effected by about a quarter of a
revolution of the shaft and preferably without the teeth of the second motion pinion
being, in the course of this movement, wholly disengaged from those of the wheel
which it drives. It will be obvious that instead of the shaft turning with the
eccentric boss it may be fixed, and the latter be a loose bush turning on it. Or, the
motion may be effected by making the axis of the second motion wheel and pinion
slide in a straight elot, or equivalent guide.
The second improvement consists in making the toothed rim of the wheel, to which
the improvement is applied, loose and with sprockets formed at intervals on its inner
periphery which are received in a groove in the rim of the body of the wheel. In
this groove, pairs of snugs are formed at intervals corresponding with the sprockets,
each sprocket being received between a pair of snugs and being free to play
between them, so that if the springs hereafter mentioned were omitted, the toothed
rim would be able to revolvo freely. In the groove in the interval between one
sprocket and its pair of snugs, and the next sprocket and its pair of snugs, spiral
springs are interposed, so that the toothed rim can move around the body of the
wheel to a limited extent controlled by the elasticity of the springs, whereby the
injurious effects of shocks are avoided.
The sprockets and snugs are of the same angular length and the springs are
compressed when they are inserted and their expansion being prevented by their
abutting at both ends both against the snugs and sprockets they at once commence to
take up the lost motion.
Any number of springs may be used, six being preferred, there being consequently
six sprockets on the rim and a corresponding number of pairs of snugs in the
grooved rim.
The grooved rim of the wheel is preferably constructed with one half of the rim
removable and each half having snugs cast on it which come opposite one another in
pairs to form abutments for the ends of the springs.
This improvement may be applied to the second or third motion gear wheels as
preferred.
According to the third improvement, a division plate in the barrel of the boiler,
extends from the front tube plate at about the normal level of the water, to a point

page_text: 5
above the rear tube plate and at a height at that end preferably somewhat above the
usual water level.
This plate serves to prevent the water flowing to the front end of the boiler and so
keeps the crown of the fire-box covered when the engine is on an incline. It also
serves to prevent priming. A blow-off pipe with cock is attached to the boiler at a
point above the front end of the division plate, so that any water which may
accumulate upon said plate can be blown out.
S. EDDINGTON.
J. E. STEEVENSON.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: We, SYLVANUS EDDINGTON and JOHN EVAN STEEVENSON, both of Chelmsford
in the County of Essex, Engineers, 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 :-
Our improvements in traction or road locomotives engines relate to the change!
gear for varying the speed at which the engine travels; to the introduction of springs
into the gear for preventing breakage of the teeth of the wheels; and to means for
preventing the uncovering of the crown of the fire-box when the engine is on an
incline, and of avoiding priming of the boiler.
The first improvement has for its object to simplify the construction of the change-
gear,
diminish the weight, and lessen the width occupied by the gear, so as to enable
the engine to be made narrower than usual; and it consists in a construction and
arrangement of the change gear whereby the second motion wheel is made movable
in its own plane towards and away from the crank shaft for the purpose of being
geared with either of two pinions of different diameters on the said shaft, the arrange-
ment being such that when the second motion wheel is in gear with either of those
pinions the second motion pinion will also be in gear with the wheol on the driving
wheel axle.
The second improvement consists of a gear wheel constructed with a loose toothed
rim and having springs, acting in a circumferential direction, introduced between said
rim and the boss of the wheel whereby limited independent circumferential motion of
the rim is permitted and shocks due to back lash or to over running are deadened,
and liability of breakage of the teeth of the gear, avoided.
The third improvement consists in the employment of a division plate in the barrel
of the boiler, the said plate extending from the front end of the boiler for such a
distance towards the fire-box as to limit the height of the water-space at the front end
and so prevent the water accumulating at the front end and the crown of the fire-box
being left wholly uncovered when the front end of the engine is on a lower level than
the firebox end.
Reference is to be had to the accompanying drawings forming part of this
specification, wherein figure 1 is a longitudinal section of a traction engine provided
with the improvements, the fast motion being in gear and parts of the framing broken
away to shew the gearing. Figure 2 is a transverse section approximately in the
plane of the second motion and driving wheel shafts. Figure 3 shows the pinions on
the crank shaft in the position they occupy when the slow motion is in gear, the
larger pinion being in section. Figures 4, 5, and 6 are detail views of parts of the
improved gear, drawn to a larger scale. The same lotters of reference indicate
the same parts in all the figures.
A is the crank shaft, B the second motion shaft, and C the driving wheel shaft.
D and E are respectively the slow and fast speed pinions upon the crank shaft. Fis

page_text: the second motion wheel, G the second motion pinion (indicated by its pitch line only,
in figure 1) and H the wheel on the driving wheel shaft in gear with said pinion.
The slow speed pinion D is keyed on the crank shaft A and the fast speed pinion E is
fitted to slide preferably on the boss of the slow speed pinion D (or on the crank
shaft A itself) with a groove and feather connection between the pinion E and the
part on which it slides. The fast speed pinion E is cupped, as shewn in cross-section
in figure 3, and is so much larger than the pinion D that when it is to be thrown into
gear with wheel F it can be slid over the pinion D so as to bring its toothed rim into
the same plane therewith, the sliding motion of the pinion E being effected by a
forked lever embracing the grooved boss of the pinion, as well understood. Or,
instead of the larger pinion being cupped, it might be of the ordinary form, the two
pinions in that case sliding together on the crank shaft with a key-way connection
between the double pinion and the shaft.
The second motion wheel and pinion F G rotate together as one, and may be moved
in a plane perpendicular to their axis, towards or from the crank shaft A, so that the
wheel F can be shifted in position as required to allow for the difference of diameter
of the fast and slow speed pinions D and E according as the one or other of these is
to be geared therewith. The preferred mode of making the second motion wheel and
pinion movable as above mentioned, by mounting said wheel and pinion to turn
loose upon an eccentric boss and journal bb carried by the overhanging end of the
second motion shaft B and by making the said shaft rotate to a limited extent in its
bearings the shaft being locked in either of its two positions by a pin 62. The radius
of eccentricity of the boss and journal is such that the necessary change of
position of the second motion wheel F will be effected by about a quarter of a
revolution of the shaft B and preferably without the teeth of the second motion
pinion G being in the course of this movement, wholly disengaged from those of the
wheel H. The arc 1-2, figure 1, shews the path described by the eccentric axis of
the second motion wheel and pinion in moving the wheel from the position (shewn
by full lines in figure 1) which it occupies when in gear with pinion E to that (shewn
by its pitch line) which it occupies when in gear with pinion D. It will be obvious
that the shaft B may be fixed and the eccentric boss and journal turn upon it;
or the motion may be effected by making the axis of the second motion wheel and
pinion F, G, slide in a straight slot or equivalent guide.
The second improvement is illustrated as applied to the second motion wheel F.
The toothed rim of this wheel is loose and has sprockets formed at intervals
around its inner periphery which are in the central plane of the wheel and are received
in a groove in the rim of the wheel body. Upon the inner sides of this groove, pairs
of inwardly projecting snugs or abutments are formed at corresponding intervals,
there being sufficient space between the opposite snugs to give free passage to the
sprockets, so that if the springs hereafter mentioned were omitted, the toothed
rim would be able to revolve freely. Each sprocket is situated between a pair of
snugs and spiral springs I are laid circumferentially in the grooved rim of the wheel
body between the successive sets of sprockets and snugs. The sprockets and
snugs i are of the same angular length and the springs are compressed when they are
inserted and their expansion being prevented by their abutting at both ends both
against the sprockets and the adjacent snugs they commence to take up the lost
motion immediately it occurs, whereby the injurious effects of shocks are avoided.
Relative circular motion of the toothed rim and the wheel body is thus permitted to a
limited extent controlled by the elasticity of the springs, as shewn in figure 6, the
rim being driven in the direction of the arrow, causing the sprockets to bear against
the one end of the springs whose other ends abut in their turn against the snugs.
Any number of springs may be used, six being preferred, there being consequently
six sprockets on the rim and a corresponding number of pairs of snugs in the grooved
riu. The grooved rim of the wheel is preferably constructed (as shewn in figure 4)
with one-half of the rim removable, both halves having snugs or abutments for the
ends of the springs. This improvement may be applied to the third motion gear
wheel H, if preferred.

page_text: The third improvement consists of a division plate K in the barrel of the
boiler, said plate extending from the front tube plate at about the normal level
of the water, to a point above the rear tube plate and at a height at that end
preferably somewhat above the usual water level. This plate prevents the water
leaving the crown of the fire box uncovered when the engine is on an incline
(as shown in figure 1). It also serves to prevent priming by maintaining a
sufficient steam space near the point where steam is taken from the boiler.
A blow-off pipe with cock is attached to the boiler at a point above the front
end of the division plate, so that any water which may accumulate upon said
plate, can be blown off.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, I declare that what I claim is ;-
1st. A change gear for a traction engine or road locomotive, consisting in the
combination of a second motion wheel and pinion so mounted as to be movable
in their own plane towards and from the first motion shaft, with first motion
change pinions of different diameters on the same shaft, and of which one at
least is movable into and out of the plane of the second motion wheel, substantially
as specified.
2nd. A change gear for a traction engine or road locomotive consisting in the
combination of a second motion wheel and pinion so mounted as to be movable
in their own plane towards and from the first motion shaft with first motion
change pinions of different diameters, the pinion of larger diameter being so
formed as to permit of its toothed rim being brought into the same working
plane as the smaller pinion, substantially as described and shewn in the drawings.
3rd. The construction of one of the gear wheels of a traction engine or road
locomotive with a toothed rim free to move circumferentially upon the body of
the wheel to an extent limited by springs interposed between abutments on the
loose rim and on the body of the wheel, and through which strains are transmitted.
4th. The construction of yielding toothed gear wheel herein described, consisting
in the combination of a loose toothed rim having internal sprockets, with a grooved
rim on the body of the wheel in which the sprockets are received, the said groove
having pairs of snugs or abutments, and with spiral springs laying in the groove
and interposed between, the sprockets of the toothed rim and the abutments in
the grooved rim, substantially as described and shewn in the drawings.
5th. In a traction engine or road locomotive, the employment of a division
plate in the barrel of the boiler extending from the front tube plate rearwards
and upwards in such position as to confine the water and prevent the uncovering
of the crown plate, substantially as described.
Dated this 6th day of September 1887.