CERTAIN IMPROVEMENTS IN LOCOMOTIVE CARRIAGES INTENDED TO BE EMPLOYED ON ORDINARY ROADS
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDMUND
LEAHY, of Cork, in the Kingdom of Ireland, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fifteenth day of January, in the ninth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Edmund Leahy, Her especial licence, full power, sole privilege and authority,
that I, the said Edmund Leahy, my executors, administrators, and assigns,
and such others as I, the said Edmund Leahy, my executors, administrators,
or assigns, should at any time agree with, and no others, from time to time
and at all times during the term of years therein mentioned, should and
lawfully might make, use, exercise, and vend, within England, Wales, and
the Town of Berwick-upon-Tweed, my Invention of "CERTAIN IMPROVEMENTS
IN LOCOMOTIVE CARRIAGES INTENDED TO BE EMPLOYED ON ORDINARY ROADS ;" in
which said Letters Patent is contained a proviso obliging me, the said
Edmund Leahy, by an instrument in writing under my hand and seal,
particularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, and to cause the same to be
enrolled in Her Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part 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, I, the said

page_text: Edmund Leahy, do hereby declare, that the nature of my said Invention,
and the manner in which the same is to be performed, is particularly
described and ascertained in and by the following description thereof, reference
being had to the Drawings hereunto annexed, and to the letters and figures
marked thereon (that is to say):-
The object of this Invention is to ease the motion and reduce the friction
of the wheels of carriages while passing over different surfaces, such as
common roads, soft ground, and irregular surfaces. The improvements
consist in the adaptation of a series of short rails to the wheels of carriages,
which rails are arranged and linked together in a manner somewhat resembling
an endless chain. The carriage, by means of these rails, may be drawn or
propelled by animal or steam or other power, and each wheel will always bear
upon at least one of the rails or links of the chain with which it is, as it were,
encircled. The chain of rails may be sustained upon the periphery of the
wheels, or upon rollers attached to the carriage and arranged around the
circumference of the wheel or wheels; or, if preferred, large rollers, having their
bearings in the framing of the carriage, may be placed in front and rear of the
carriage wheels, to support the chains of rails, and guide them under and over
the carrying wheels as the carriage is drawn or propelled forward. The
first arrangement will be found the simplest, viz., having the chain of rails
sustained by means of rollers or otherwise on the periphery of the wheels
which sustain the carriage and load. In this case, the upper part or half
circumference of the wheels sustains the chain of rails, excepting only those
links or rails that may be under the wheel, and resting on the ground, to
receive the wheel as it rolls along. By this arrangement the chain of
rails, when on, under, and around the wheel, presents the appearance of a
polygon circumscribing the circle of the wheel. The arrangement of the chain
of rails should not, however, resemble with accuracy such a circumscribing
polygon. They should have somewhat greater length than such an accurate
polygon, thereby admitting of the necessary motion which almost continually
takes place in the rails or links when in use, because one link (and sometimes
more) will be always on the ground and immoveable whilst the wheel is rolling
over it, all the other links or rails having at the same time a motion corre-
sponding very nearly with that of the wheel which they encircle.
They will
also be found to have a secondary but short local motion between themselves
backwards and forwards on the periphery of the wheel. According as the
wheel has passed over one link or rail, it is taken up behind by the rotary motion
of the wheel, and another is at the same time dropped down in front, which,
resting on the ground, alike to the former, the wheel rolls over it in like

page_text: manner, and so on; each link or rail, being successively brought under the
wheel, remains stationary on the ground whilst the wheel is passing over it,
and produces the same effect as a continued line of railway or tramway made
with edge rails or plate rails, each equal in length to a link in my circum-
scribing chain of rails. When the chains of rails get motion by being
sustained upon the periphery of the working or principal wheels of the carriage,
the speed of the circumscribing polygons or chains of rails will vary slightly
from that of the wheels which respectively carry them, and consequently the
wheels will move the links or rails through a space differing in some degree
with that which they themselves pass through. I have also designated this
as "a local motion," it being confined to the links or rails themselves. I have
already mentioned that another such motion is found to exist consequent on
some one link or rail of the chain being of necessity stationary on the ground
whilst the wheel is moving upon it.
In the accompanying Drawings I have shewn two methods or plans by which
I am enabled to prevent any considerable friction of the chains while travelling
round the. carriage wheels. One mode is by applying elastic wheels or elastic
friction rollers to. the links or rails. These rollers are designed to ease the
"local motion" of the rails, and prevent their surfaces from coming into contact
with the periphery of the wheels excepting only when the rails or links are
bearing on the ground: The rollers, bearing upon the working or principal
wheels, freely permit that slight "local motion" in the rails when passing
round the upper part of the wheel above alluded to, and at the same time the
rollers, being. themselves sufficiently elastic, under certain pressure will yield
readily when they are underneath the wheels, and thereby oppose no material
obstruction to the perfect and continuous contact of the periphery of the wheel
and the surface of the rail or rails upon the ground. The other mode of
accomplishing the same object, viz., preventing any considerable friction of the
chains against the periphery of the carriage wheels, is by attaching elastic
circular bands to the wheels, over which bands solid or inelastic rollers
attached to the sides of the links or rails are made to run, in order to keep the
links or rails free from the upper part of the periphery of the wheels. Both
these contrivances will be the less needed in practice as larger wheels are used,
and as the links or rails are reduced in length to about a twentieth part or less
of the circumference of the wheel. In general, it may be said that the use of
rollers will be less and less necessary according as the length of each link or
rail is reduced; but it is obvious that in practice they must not be made much
if anything shorter than twelve or eighteen inches each, and therefore carrying
wheels of large diameter will be found most advantageous.

page_text: DESCRIPTION OF THE DRAWINGS.
Note. The same letters correspond with similar parts in all the Drawings,
unless when otherwise specially described; it is not therefore deemed necessary
to repeat the description of each Drawing when similar parts happen to have
been described on any one.
Fig. 1, Sheet 1, represents the chain of rails or links provided with elastic
friction rollers, and applied around the wheel of a carriage. Fig. 2 is a cross
section of the upper part of the wheel taken in the line a, a, of Fig. 1, and
shewing the relative position of the rails with respect to the periphery of the
wheels. Fig. 3 is a section taken through the middle of the lower rails, and
shewing the wheel travelling over their flat surface. In this Figure the wheel.
is represented as passing over the junction of two rails, which lie flat upon.
the ground.
Fig. 1, Sheet 2, represents an arrangement, in which solid friction rollers
are employed in place of the elastic rollers. In this case an elastic band is
attached to the wheel, and upon it the solid rollers work. A represents the
axle of the wheel; B, the nave; C, a dovetailed clamp and guide for the
elastic band of the wheel (see Sheet 2); D, the links or rails arranged as a
chain around the wheel; E, Sheet 1, is the periphery upon which the elastic
rollers work; E, Sheet 2, is the elastic band upon which the solid rollers
work; F, the side view of the elastic rollers fixed to the rails or links, the cir-
cumference of each roller being connected with its centre by means of an elastic
spiral spoke or spokes in place of rigid spokes; F', side view of the solid rollers
fixed on the connecting or joint pins of the rails or otherwise; G, the centre
or screw pin or joint pin connecting the links or rails upon which they turn;
K, the felloes of thewheel; S, the surface over which the carriage moves.
Fig. 1, Sheet 3, represents a side view of a link or rail, in which h, h¹,
represent the feet of the rails; 9, 9', the eyes for the joint pins to connect the
adjoining rails. Fig. 2, a section of Fig. 1 (on the line c, d). k, the surface of
the rail; h, h¹, the feet. Fig. 3, a section of Fig. 1 (on the line a, b). F, elastic
rollers; n, n, the sides or flanges of the rails. Fig. 4, an end view of Fig. 1.
Fig. 5, ground plan of Fig. 1. h, h, the feet, which bear upon the ground;
k, k, the surface of rails on which the wheel moves. Fig. 6, plan shewing the
position of the feet of two adjoining links or rails on the ground at the moment
the wheel is passing from one rail to another.
I, Fig. 2, Sheet 1, represents the circumference or binding of the wheel; K,
the felloes; k, the surface of the rails; E, the periphery on which the elastic
rollers bear; F, the elastic rollers.

page_text: Fig, 2, Sheet 2, is a section of Fig. 1, taken in the line x, x. E¹ is the
elastic band; C are clamps and guides, in which projecting pieces C*, C*,
attached to the elastic band E', work.
Having now particularly described my Invention, I wish it to be understood
that I claim, under the above in part recited Letters Patent, the construction
and arrangement of rotating rails as above set forth.
In witness whereof, I, the said Edmund Leahy, have hereunto set my
hand and seal, this Fifteenth day of July, in the year of our Lord
One thousand eight hundred and forty-six.