IMPROVEMENTS IN PROPELLING
Year: 1852

page_text: LETTERS PATENT to Thomas Allan, of Adam Street, in the City of.
Westminster, Civil Engineer, for the Invention of." IMPROVEMENTS
IN PROPELLING."
Sealed the 16th March 1853, and dated the 1st October 1852.
PROVISIONAL SPECIFICATION left by the said Thomas Allan at
the Office of the Commissioners of Patents, with his Petition,.
on the 1st October 1852.
I, THOMAS ALLAN, of Adam Street, in the City of Westminster,
Civil Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN PROPELLING" to be as follows:-
These improvements are based on one general principle, namely, the
using of the spring as the retainer, accumulator, and transmitter of the
full force of the power applied, thus overcoming that rigidity of impulse
which necessarily pervades all applications of power against a non-
elastic fluid like water or other rigid fulcrum.
I propose for paddle wheels that the radii of the wheels should be
formed of strong compound springs, the effect of which on the engine
or propelling machine will be to ease it under circumstances of severe

page_text: pressure or shock, such as is given in a heavy rolling sea, and will go
far to prevent the derangement and damage to the propelling of the
machinery which might otherwise occur. The engines would also work
more steadily and easily and with less strain, than when a rigid and
unyielding propeller is-employed. The effect will be something
analogous to a man with a springy oar rowing against another with the
straight unshaped piece of wood (although with the same surface of
blade). In applying this principle to the screw I propose forming the
screw of a series of spring blades, the. one resting on the other, and
each blade progressively increasing in length, the whole together being
shaped like the tail of any fast swimming fish. Other arrangements
may be found as effectual and more simplified.
For locomotive driving wheels I propose to make the spokes all
springs, and in some-instances-and in some respects the tyres likewise.
The springs could be formed like a C spring, fixed to the nave and
joined to the inside of the tyre. The tyre in some cases might be made
of the continuation of the C spring, and likewise form part of it, which
again would require an outer tyre of vulcanized india-rubber or other
pliable substance.
:
In the case of a locomotive on common roads this construction of
wheel would take a greater grip of the ground,,and thus overcome the
tendency to slip to which common road gradients necessarily subject
motive machinery.
Other forms of springs may be used, and this principle may be applied
to wheels for vehicles generally in various ways, so as even to dispense
with the springs now.eniployed.nt

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of October, in the year. of
our Lord One thousand eight hundred and fifty-two, in the sixteenth
year of Her reign, did, Herself, Her heirs and successors, give
the for
and grant unto me, the said Thomas Allan, Her special licence that
I, the said Thomas Allan, my executors, administrators, and assigns,
or such others as I, the said Thomas Allan, my executors, administra
tors, 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 PRO-
PELLING," upon the condition (amongst others) that I, the said Thomas
Allan, 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 immediately after the date of the said Letters Patent!
NOW KNOW YE, that I, the said Thomas Allan, do hereby declare
the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and
by the following statement, that is to say:
My improvements are founded on one general principle, which is
that of the application of the spring as the retainer; accumulator, and
transmitter of the full effect of any motive p power, whether employed in
propelling vessels by means of the paddle wheel or screw, or carriages
on railways or common roads by means of driving wheels, whereby I am
enabled to overcome the difficulties arising from the rigidity of inipulse
necessarily attendant on the application of motive power when³ acting
against a non-elastic fulcrum, such as water in the case of the paddle
wheel and screw, and the rails or roads in that of the driving wheels
In applying my improved principle of action to paddle wheels for the
propulsion of vessels I form the spokes or radii of the wheel of strong
compound springs, to which the float boards are attached by screws,
bolts and nuts, as usual, and either with or without a rim to the
'the wheel?
or

page_text: The springs used in forming the spokes of the wheel may be of any
approved construction, and either tapering away from the boss to the
extremity of the spoke, or of the same thickness throughout their length,
and the number of plates used and their thickness will depend on the
diameter of the wheel and the strain to which it is likely to be exposed.
Additional springs, extending from spoke to spoke, on each side of the
wheel might also be used, to enable the spokes to withstand better the
effects of their concussion against the water.
The probable effect of this arrangement will be to relieve the engine
or propelling power from a considerable portion of the severe strain
experienced in a heavy rolling sea, and thus to reduce the chance of
damage to the engines and wheel, whilst under ordinary circumstances
the engines will work with greater freedom and ease, and a much
greater speed will be attained.
When I apply my improvements to screw and other similar sub-
merged propellers I make the blades or arms of a series of steel plates
or springs, the central ones being the longest, and the side plates
gradually reduced in length, so as to make the thickness of each blade
taper or diminish gradually from the boss to the extreme point. Or I
form the blades of a series of plates of spring steel, gradually diminishing
in length, placed side by side against each other, the longest being
towards the extremity of the shaft, so that the entire screw formed in
this manner is not unlike the tail of any fast swimming fish. By this
means the blades may be set at a much higher pitch than usual, so that
a higher speed will be obtained, and the jarring and vibration produced
by the blade of the screw, which is for the time being undermost, work-
ing in denser water than the upper one, will be greatly reduced, if not
entirely removed.
In applying my improved system of construction to the driving
wheels of locomotive engines I make the spokes of springs, and in
some cases the tires also, either wholly or partially. The spring spokes
might be formed like the C spring, or the volute, being fixed at one
end to the nave, and at the other to the interior of the tire. The tire
might also be composed by continuing the spring spokes in length,
and bending the super-requisite lengths into a circular form, and then

page_text: encircling the whole with an outer tire of vulcanized india-rubber, solid
or tubular, or other elastic substance. In the case of a locomotive for
common roads this construction of wheel would take a greater grip of
the ground, and thus overcome that tendency to slip, which has hitherto
proved the great obstacle to locomotive progress on common roads, where
the gradients vary considerably.
And having now described the nature of my said Invention, and in
what manner the same may or is to be performed, I declare that what
I claim is,
The introduction and application of springs in the construction of
propellers for vessels (whether on the principle of the paddle wheel or
screw), and in the driving wheels of locomotive engines for railways
and common roads, in the manner and for the purposes herein-before
explained.
In witness whereof, I, the said Thomas Allan, have hereunto
set my hand and seal, this Thirtieth day of March One thousand
eight hundred and fifty-three.
THOMAS ALLAN. (L.S.)