IMPROVEMENTS IN THE CONSTRUC- TION OF TRACTION ENGINES
Year: 1863

page_text: LETTERS PATENT to Thomas Aveling, of Rochester, in the County of
Kent, Engineer, for the Invention of "IMPROVEMENTS IN THE CONSTRUC-
TION OF TRACTION ENGINES."
Sealed the 16th June 1863, and dated the 7th January 1863.
PROVISIONAL SPECIFICATION left by the said Thomas Aveling at the
Office of the Commissioners of Patents, with his Petition, on the
7th January 1863.
I, THOMAS AVELING, of Rochester, in the County of Kent, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF TRACTION ENGINES," to be as follows:-
The object of this Invention is to improve the construction and efficiency
of traction engines. In these engines the motion is communicated through
gearing from the crank shaft to the driving wheels. The intermediate
gearing I mount on a counter shaft, the bearings for which I form in the
same brackets that carry the crank shaft. Keyed to the opposite ends of the
counter shaft are spur wheels having different numbers of teeth to suit twc
different speeds of driving, and into these wheels gear spur pinions of varying
diameter on the crank shaft. These pinions are free to slide on their shaft
in order that either may be thrown into action at pleasure according to
the driving speed required. They are by preference shifted by hand and kept
in or out of gear, as the case may be, by the application of elastic clips com-
posed of leather and steel which clasping the shaft at either side of the boss

page_text: of the pinions, will act like a fixed collar. on the shaft and maintain them in
the required lateral position. The driving motion I prefer to transmit through
a chain and chain pinion and wheel. The chain pinion is keyed to the
counter shaft, and to allow of the slack of the chain being taken up, I set the
counter shaft bearings in segment slots struck from the axis of the crank shaft.
The bearings may be raised to any required height suitable for bringing the
chain to tension by means of blocks and then held firmly by binding screws.
For still further varying the speed it is only necessary to shift the chain
pinion for one of less or more teeth.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Aveling in the Great Seal Patent Office on the
7th July 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
A FELING, of Rochester, in the County of Kent, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of January, in the year of our
Lord One thousand eight hundred and sixty-three, in the twenty-sixth year of
Her reign, did, for Ilerself, Her heirs and successors, give and grant unto me,
the said Thomas Aveling, Her special license, that I, the said Thomas Aveling,
my executors, administrators, and assigns, or such others as I, the said Thomas
Aveling, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF TRACTION ENGINES," upon the condition (amongst others) that I,
the said Thomas Aveling, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and imine-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Aveling, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-

page_text: This Invention relates to the application to traction engines of certain
improvements in their details of construction with the view both of simplifying
their construction and greatly enhancing their efficiency. It is well known
that it is desirable to change the relative speeds of the carrying wheels and
the crank shaft according to the. varying levels or the character of the ground
over which the engine is travelling. To effect this, many.complex or cumbrous
contrivances have been adopted which not only increased, the weight but the
cost of the engine. I now propose to attain this end by the novel means
shewn in the accompanying Drawing, in which Fig. 1 is a side elevation
and Fig. 2 an end view of so much of a traction engine as will serve to
explain the nature of my improvements, the motion of the crank shaft being
transmitted through an endless chain (according to my Patent of September
the First, One thousand eight hundred and fifty-nine, No. 1995;) to the
driven wheel. The carrying wheels A, A*, are made broad and cast with an
annular rib in the middle of the periphery for running on hard ground and
with lateral projections for ensuring a firm bite of the ground. On the boss of
the wheel A is keyed the ordinary chain wheel B, round which the chain C
passes from a chain pinion D. This chain pinion is keyed on to a transverse
shaft E which is carried by brackets F that serve also to carry the crank
shaft G. By thus mounting these two shafts E and G on the same brackets
the use of additional fastenings for securing the brackets to the boiler are
avoided, while at the same time, by the peculiar arrangement of the shafts,
the distance between the chain pinion D and the crank shaft G is increased
sufficiently to permit of the use of a larger diameter of pinion than usual,
which is a matter of considerable importance as respects the maintenance of
the gearing in efficient working order. Keyed to the opposite ends of
the counter shaft E are spur wheels H, H*, having different numbers of teeth
to suit two different speeds of driving, and into these wheels gear spur pinions
1, 1, of varying diameter on the crank shaft. These pinions are free to slide
on feathers.on their shaft in order that either may be thrown into action at
pleasure according to the driving speed required. They are by preference shifted
by hand and kept in or out of gear as the case may be by the application of
elastic clips composed of a strip of thin steel lined with leather. The clips are
made to clasp the shaft and retain their position thereon. But when the pinions
require to be shifted the clips are first taken off the shaft and the pinions being
shifted laterally by hand the clips are again applied, but so as to bear against
either side of the boss of the pinions. They will thus act like a fixed collar
on the shaft, maintaining the pinions in the required lateral position. To
allow of the slack of the chain C being taken up, the counter shaft bearings

page_text: are set in segment slots in the brackets F, as shewn best in the detached view
Fig. 3. The segment slot it will be seen is struck from the axis of the crank
shaft G. The bearings of the counter shaft may be raised to any required
height (within the limits of the slotted brackets) suitable for bringing the
chain to tension by the insertion of blocks a, a, below the bearings, and they
are then to be held firmly by a binding screw b. From this explanation it
will be understood that when it is desired to reduce the speed transmitted to
the driven wheel in order that the engine may be enabled to ascend an incline,
it will only be necessary to throw the small pinion I into gear with its spur wheel
H, the larger pinion I* being slidden out of gear with its spur wheel H*.
It will also be seen that when the greatest stress is put on the gearing the
strain will be directly through the gearing, and thus the counter shaft E will
not suffer from torsion. When however the work is less severe the motion will
be transmitted through the pinion and wheel I*, H*, and thence through the
shaft E to the chain pinion D. In order to provide for a still further variation
of speed it is only necessary to change the pinion D for one of less or more
teeth, and two additional speeds will be thereby obtained.
Having now set forth the nature of the Invention of "Improvements in the
Construction of Traction Engines," and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part
recited Letters Patent, I claim the construction of the brackets F as described
for carrying the crank shaft and counter shaft and allowing of the latter being
raised or lowered to suit the length of the endless chain, and also the mode
of transmitting the power to the chain pinion from the crank shaft by sliding
pinions mounted on that shaft and working into spur wheels on the axle of
the chain pinion.
In witness whereof, I, the said Thomas Ave. ing, have hereunto set
my hand and seal, the Second day of July, in the year' of our
T
One thousand night hundred and sixty-three.
THO. AVELING. (L.S.)