VARIOUS IMPROVEMENTS IN THE CONSTRUCTION OF LOCOMOTIVE ENGINES
Year: 1815

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, RALPHI
DODDS and GEORGE STEPHENSON, both of Killingworth, in the County of
Northumberland, Engineers, send greeting.
WHEREAS His present Majesty King George the Third, in and by His Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster, the
Twenty-eighth day of February last, and in the fifty-fifth year of His reign, for
Himself, His heirs and successors, did give and grant unto us, the said Ralph
Dodds and George Stephenson, our exors, adññors, and assigns, His especial
licence, full power, sole privilege and authority, that we, the said Ralph
Dodds and George Stephenson, our exors, adñiors, and assigns, and every of
them, by ourselves and themselves, or by our and their deputy or deputies,
servants or agents, or such others as we, the said Ralph Dodds and George
Stephenson, our exors, adññiors, or assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend our new Invention of "VARIOUS IMPROVEMENTS IN THE CONSTRUCTION OF
LOCOMOTIVE ENGINES," within that part of the United Kingdom of Great Britain
and Ireland called England, tho Dominion of Wales, and Town of Berwick-
upon-Tweed, in such manner as to us, the said Ralph Dodds and George
Stephenson, our exors, adññiors, and assigns, should seem meet; and that we,
the said Ralph Dodds and George Stephenson, our exors, adñiors, and assigns,
should and lawfully might have and enjoy the whole profit, benefit, commodity,
and advantage from time to time coming, growing, accruing, and arising by
reason of our said Invention, for and during the said term of years therein

page_text: mentioned, and in which Letters Patent there is contained a proviso
obliging us, the said Ralph Dodds and George Stephenson, or the one of us,
particularly to describe and ascertain the nature of our said Invention, and
in what manner the same is to be performed, by an instrument in writing
under our hands and seals, or under the hand and seal of one of us, and to
cause the same to be enrolled in His Majesty's High Court of Chancery within
two calendar months next and immediately after the date of the said recited
Letters Patent, as in and by the same, reference being thereunto had, will
more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
Ralph Dodds and George Stephenson, do hereby describe and ascertain the
nature of our said Invention, and in what nauner the same is to be per-
formed, by the Plan or Drawing in the margin of these presents, and the
following description thereof, that is to say :-
The friction of four wheels propelled by two engines A, A, Fig. I., will
propel several tons weight upon iron railway, and the only method of pro-
pelling these wheels before our said Invention was by a cog wheel upon each
bearing axis, spurred on by a cog wheel upon each engine's axis, with an inter-
leading cog wheel to combine the two engines together to keep them at right
angles from one another, by which means the engines are propelled forward;
but these cog wheels are always liable to wear from the irregularity of the
waggonway or railway upon which they are propelled, consequently they soon
require to be renewed, and that at a considerable expence, besides there is a
great risk of breaking these wheels from the backlash or returning stroke of
the engine, which is so heavy as to cause a jolt through the whole machinery,
in consequence of the open space worn in the teeth of the cog wheels, and
it likewise causes the bearing wheels to hitch upon the railway at the
returning stroke of the engine. There was also, before our said Invention, a
method of two engines being combined together with cog wheels, which spur
themselves along a cog railway or waggonway, which cog railway or waggon-
way is attended with considerable expence in laying and relaying the same;
therefore, to obviate the inconveniences arising from the use of cog wheels
and cog railways or waggonways, we, by our said Invention, apply the power
of the engine to the travelling wheels by joining one end of each connecting
rod a, a, Fig. I. and Fig. II., to a pin fixed to one of the spokes b, b, Fig. I.
and Fig. II. of each of the travelling wheels of the carriage B, Fig. I., and
B, B, Fig. II., and the locomotive power C, Fig. I., and the other end of the
connecting rods, to the engine yoke c, c, Fig. II., which connecting rods must
be joined at both ends by ball and socket joints to give way to the rise and

page_text: fall of the road; likewise there must be a joint f, where the piston rod e,
Fig. II., is joined to the yoke c, c Fig. II., that it may give way to the ball
and socket joints. The two engines are combined together and kept at their
proper distance by each bearing axle having two cranks g, g, and h, h, Fig. I.,
near their centres with two connecting rods i, i, Fig. I., extending from one
crank to the other, which cranks must be fixed at right angles from one
another, as is represented in Fig. I.
Our said Invention also consists of another method of combining the two
engines together by fixing two grooved wheels a, a, Fig. IV., the centre of
each bearing axle B, B, Fig. IV., with an endless chain g, g, Fig. IV., to work
in the said grooves, by which means the engines are combined together, as
well by the endless chain as by the use of the aforesaid cranks. The grooved
wheels must have notches cut in the inside of them, as shewn in Fig. IV.,
where a, a, represent a side view of the inside of the grooves in order that the
projecting bolts of the chain may fall into the same notches, which will of course
supply the place of and also be much superior to cog wheels, besides
possessing another evident advantage of combining machinery together at any
convenient distance by lengthening the chain so as to avoid the use of a
multiplicity of cog wheels. Fig. V. is a transverse section of the chain (upon
a larger scale) shewing the bolts projecting from each side of the chain, which
fall into the notches of the grooved wheels h. Fig. II. also shews an end
view of the inside of one of the grooved wheels fixed in the centre of the
bearing axle k, k, Fig. II.
By the above method of applying the friction of the bearing wheels, the
engines, by our said Invention, propel sixty tons or upwards upon iron rail-
way; but should a greater burdon be required to be propelled, we then apply
the friction of two other wheels Fig. III., which wheels carry the water for
supplying the engine by attaching a groove a, a, Fig. III., to each of the last-
mentioned wheels, and a groove k, k, Fig. I., or 1, 1, Fig. II., upon the last
two bearing wheels of the carriage, with an endless chain m, m, to fall into the
said grooves, by which, when a part of the burden is added to the additional
wheels, the chain is immediately drawn tight into the grooves fixed to the said
wheels, and by the propelling force of the engine makes the chain move the
bearing wheels of the water carriage, and consequently applies the friction of
them to facilitate the propelling of the burden required. The great benefit
that will be derived from the adoption of our said Invention is, that there is no
alteration required in the waggonway, whether of wood or of iron; no cog
wheels to propel it forward; and by its simple construction we can make them
at a moderate expence, which will be a great saving, besides a great advantage

page_text: and utility to the public, particularly to those collieries that are at a remote
distance from the rivers. It is already known to the public that self-acting
locomotive engines have been used for drawing carriages; but this Specifica-
tion does not include as our Invention what has been known before, but
includes the Invention of applying the locomotive engine to the travelling
wheels, and combining the engines together by cranks or endless chains, as
before explained, which has neither been publicly carried into effect, nor been
included in the Specification of any prior Letters Patent granted to any
person or persons whomsoever.
. In witness whereof, we have hereunto set our hands and seals, the Eighth
day of April, in the fifty-fifth year of the reign of our Sovereign Lord
George the Third, by the Grace of God of the United Kingdom
of Great Britain and Ireland King, Defender of the Faith, and in the
year of our Lord One thousand eight hundred and fifteen.
AND BE IT REMEMBERED, that on the Eighth day of April, in the year
of our Lord 1815, the aforesaid Ralph Dodds and George Stephenson came
before our said Lord the King in His Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stampt
according to the tenor of the Statute made for that purpose.