IMPROVEMENTS IN ROAD LOCOMOTIVES AND TRACTION ENGINES."
Year: 1880

page_text: LETTERS PATENT to James Marshall, of Gainsborough, in the County of
Lincoln, for an Invention of "IMPROVEMENTS IN ROAD LOCOMOTIVES AND
TRACTION ENGINES."
PROVISIONAL SPECIFICATION left by the said James Marshall at the
Office of the Commissioners of Patents on the 14th October 1880.
JAMES MARSHALL of Gainsborough, in the County of Lincoln. " IMPROVE-
MENTS IN ROAD LOCOMOTIVES AND TRACTION ENGINES."
This Invention relates to the arrangement of the driving gear of road locomotive
or traction engines, in such manner as without the use of sleeves or pinions sliding on
feathers to enable the speed to be altered, by putting into gear one wheel and
pinion, which may be effected by means of a lever of simple form, and whereby
also the crank shaft may be thrown out of gear with the main axle when the
engine is required for driving machinery off the fly wheel.
For these purposes on the crank shaft are keyed two pinions of different
diameters arranged a certain distance apart; parallel with the crank shaft is a counter
shaft able to move lengthwise. On this counter shaft are keyed, two wheels of
suitable diameters for gearing into the pinions of the crank shaft, the larger of the
wheels on the counter shaft being designed to gear with the smaller pinion of the
crank shaft, and the smaller wheel of the counter shaft with the larger pinion of
the crank shaft.
In one position of the counter shaft its two wheels are out of gear with both
pinions of the crank shaft, but by moving the counter shaft endwise in one
direction or the other, one or other of its wheels will be brought into gear with the
corresponding pinion of the crank shaft, according as the fast or slow speed is
required.
The counter shaft is provided with a broad pinion, which notwithstanding the
endwise movements of the shaft remains constantly in gear with a wheel keyed on
a second counter shaft, from which motion is communicated to the main axle in the
usual manner. This broad pinion is provided with a wide shroud of not less
diameter than the tops of the teeth, and the first counter shaft bearing is made of
sufficient diameter so as to allow the pinion to slide into it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Marshall in the Great Seal Patent Office on the 12th April
1881.
JAMES MARSHALL, of Gainsborough, in the County of Lincoln.
IN ROAD LOCOMOTIVES AND TRACTION ENGINES."
"IMPROVEMENTS
This Invention relates to the arrangement of the driving gear of road locomotive
or traction engines, in such manner as without the use of sleeves or pinions sliding
on feathers to enable the speed to be altered by putting into gear one wheel and
pinion, which may be effected by means of a lever of simple form, and whereby also
the crank shaft may be thrown out of gear with the main axle when the engine is
required for driving machinery off the fly-wheel.
For these purposes, on the crank shaft are keyed two pinions of different
diameters arranged a certain distance apart; parallel with the crank shaft is a counter
aliaft able to move lengthwise. On this counter shaft are keyed two wheels of
suitable diameters for gearing into the pinions of the crank shaft, the larger of the
wheels on the countershaft being designed to gear with the smaller pinion of the
crank shaft, and the smaller wheel of the counter shaft with the larger pinion of
the crank shaft.
In one position of the counter shaft its two wheels are out of gear with both
pinions of the crank shaft, but by moving the countershaft end wise in one direction
or the other, one or other of its wheels will be brought into gear with the
corresponding pinion of the crank shaft, according as the fast or slow speed is
required.
The counter shaft is provided with a broad pinion, which notwithstanding the
end wise movements of the shaft remains constantly in gear with a wheel keyed on
a second countershaft, from which motion is communicated to the main axle in
the usual manner.
This broad pinion is provided with a wide shroud of not less
diameter than the tops of the teeth, and the first countershaft bearing is made of
sufficient diameter so as to allow the pinion to slide in it.
Referring to the accompanying Sheet of Drawings
Figure 1 is a side elevation of the hinder part of a road locomotive fitted with
gearing according to my Invention.
Figure 2 is an end elevation of the same.
Figure 3 is a top plan partly in section of the gearing.
On the crank shaft A are keyed two pinions E and F of different diameters,
E being the small and F the larger pinion.
On the first countershaft B are keyed two wheels G and H of suitable diameters
for gearing into the pinions E and F respectively; on the opposite end of the first
countershaft B is keyed a broad pinion J. In Figures 3 the wheels G and H are
shewn in such a position as to be out of gear with both of the pinions E and F,
If the countershaft B on which the wheels G, H, are keyed be slid lengthwise
in either direction, either the wheel G will be brought into gear with pinion E, or
the wheel H will gear with pinion F, as the case may be. E and G gearing together
give the slow travelling speed, and F and H gearing together give the quick
travelling speed. To produce the changes of speed and also to throw the counter-
shaft out of gear, the said countershaft B is moved endways by the arrangement of
lever R (whose fulcrum is at R'), screw S, and handwheel T, shewn in Fig. 2. The
broad pinion J (like the wheels G and H).is keyed firmly to the shaft B, and is made
sufficiently broad on its face not to be thrown out of gear with the wheel M by
the endwise movement of the countershaft B in either direction. To prevent the
pinion J from overhanging its bearing excessively in any of its three positions, it
is provided with a wide shroud, of which the diameter is not less than the diameter

page_text: of the circle described by the tops of the teeth, and the bearing N of the first
countershaft B is made of such internal diameter or bore as to allow the broad pinion
to slide and rotate in it. The wheel M is keyed on to the second countershaft O,
from which motion is communicated to the main axle in the usual manner.
Having now described the nature of the said Invention, and the manner in which
it is to be or may be carried into practical effect, I would have it understood that
what I consider to be novel and original, and therefore claim as secured to me
under the Letters Patent hereinbefore in part recited is, in a traction engine or road
locomotive, the arrangement hereinabove described and shewn for transmitting
fast or slow motion at will from the crank shaft to the travelling mechanism, and
particularly I claim providing for endwise movement of the first countershaft and
the wheels keyed or fixed upon it, by the use of a broad pinion keyed or fixed upon
such shaft, and a bearing in which that pinion is able to slide whilst remaining
in gear with the second countershaft or travelling mechanism, substantially as
described.
In witness whereof, I, the said James Marshall, have hereunto set my hand
and seal, this Eleventh day of April, in the year of our Lord One thousand
eight hundred and eighty one.
JAMES MARSHALL. (L.S.)