IMPROVE- MENTS IN DRAWBRIDGES APPLICABLE TO RAIL AND OTHER ROAD-WAYS
Year: 1854

page_text: PROVISIONAL SPECIFICATION left by tho said James Brunlees at the
Office of the Commissioners of Patents, with his Petition, on the 28th
June 1854.
I, JAMES BRUNLEES, of Manchester, in the County of Lancaster, Civil
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN DRAWBRIDGES APPLICABLE TO RAIL AND OTHER ROAD-WAYS" to be as
follows:-.
My Invention consists in so constructing the road-ways of bridges that they
shall be capable of being lowered below the general level, and drawn backward
beneath the surface thereof. For instance, suppose it be desired to construct
a railway across a stream which is required at times to be free for navigation;
I mount the rails in any suitable manner upon piers, beyond which on one
side I cause the moveable part to extend, and there support it by apparatus
which may be removed at pleasure; when it is desired to withdraw the bridge,
these supports are lowered, and the rails allowed to descend, by a slight pre-
ponderance of weight at that end, until it is below the general level, and

page_text: resting upon an inclined plane. along which and beneath the roadway it is
drawn by means of a rack and pinions. The bridge is again formed by turning
the pinions in the contrary direction, and is secured in its proper position by
suitable attachments.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Brunlees in the Great Seal Patent Office on the
27th December 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
BRUNLEES, of Manchester, in the County of Lancaster, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of June, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said James Brunlees, Her especial license that I, the said James Brunlees,"
my executors, administrators, and assigns, or such others as I, the said
James Brunlees, 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
DRAWBRIDGES APPLICABLE TO RAIL AND OTHER ROAD-WAYS," upon the condition
(amongst others) that I, the said James Brunlees, 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 J, the said James Brunlees, 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 and accompanying Drawings (that is to say) :-
My Invention consists in so constructing the roadways of bridges that they
shall be capable of being lowered below the general level, and drawn backward
beneath the surface thereof.

page_text: In order to illustrate my Invention, I shall suppose it desired to construct a
railway across a river which is required at times to be free for navigation, and
the accompanying Drawing will shew a method by which this may be carried
into practical effect.
Fig. 1 is an elevation, partly in section, and Figs. 2 and 3, transverse
sections. The general construction of the bridge may be regulated according
to desire, and forms no part of my Invention; but the construction I have
shewn is supposed to be of iron. The permanently fixed roadway extends to
the right of E, and to the left of F, between which two points the moveable
part is applied.
Constructed as shewn in the Drawing, this part is formed of lattice girders
a, supporting transverse planks of wood b, to which are attached longitudinal
sleepers c, carrying rails d of any ordinary form. Beneath the drawbridge are
situate inclined rails e, mounted upon lattice girders f, which are supported on
pillars g; two other pillars g are provided with bearings, within which is placed
a shaft h, provided at one end with a worm wheel i, the teeth of which are in
gear with a worm j, fixed to an upright shaft k, turning in a socket carried by
the pillars of the bridge, and furnished at its upper end with a winch handle 7,
above a platform m. Upon the shaft h are two excentrics n, which when
turned upwards (as shewn in Fig. 1) by means of the winch handle 1, are
beneath the lower surface of the drawbridge, and become supports for it at onc
end. In order that the excentrics n may not be turned beyond the proper
distance, they are provided with pins, which pass into slots formed in lugs o,
attached to the bridge, which therefore act as stops, by which the motion of the
shaft is determined. In order to prevent the excentrics from turning in the
other direction when used as supports, I adapt to the shaft k a notched wheel
situate within the platform m, into which wheel a catch is placed, when the
proper position has been obtained. The other end of the drawbridge rests
upon two pillars, and is provided with plates (one of which is shewn at p),
furnished with holes, through which a bolt 7 passes, such bolt, however, being
capable of withdrawal by means of a lever connected thereto, and extending
upward above the level of the roadway. These two apparatus form supports
at either end, but the bridge has a bearing about its centre, by the contact of
one pair of a series of rollers r, which rest upon the inclined rails e. Beneath
the centre of the drawbridge is attached a toothed rack s, in gear with which is
a pinion t. mounted upon a shaft u, supported by the pillars; this shaft has a
toothed wheel v, in gear with a pinion w, affixed to a shaft x, upon which
there is a winch handle, capable of being turned from the platform. The railings.
y on either side of the drawbridge are affixed to stationary parts, and always

page_text: remain therefore in the position shewn. According to the position shewn in
Fig. 1, the bridge is adapted for being passed over, the rails of the stationary
part and those at d being on a level. When the withdrawal of the bridge is
required, the bolt q is to be withdrawn, so as to liberate one end thereof, the
shaft h being then caused to revolve, so as to turn downward the excentrics n;
a slight preponderance given in construction to the drawbridge will cause it to
drop at the end E, until a series of rollers r shall have arrived in contact with
the inclined rails e, mounted upon the girders f; this change of position will
have brought the upper surfaces of the rails d' beneath the transverse framing
which carries the rails, and upon the shaft u being now turned, the pinion t
will, by operating on the rack s, cause the bridge to move along the incline
until arrested at G, and the river will be free, as required. This position of the
parts is shewn in the transverse section, Fig. 3. When it is required to restore
the roadway, the same operations in a reversed direction will effect that object.
I have in the foregoing description given as an example a railway bridge
situate across a river, but it will be evident that my Invention may be adapted
to ordinary roadways, and that it may be applied to other situations, as, for
instance, crossings of other lines of rail or other roads or canals, which crossings
are required occasionally to be removed. I would also observe, that although
I have shewn certain mechanical means whereby the moveable part may be
supported and withdrawn, I do not confine myself thereto, as the same may
be modified to suit particular purposes, and which modifications will readily
suggest themselves to all competent persons.
Having thus described and ascertained the nature of my said Invention, and
the manner in which the same is to be performed, 1 desire it to be under-
stood that I claim, as secured to me under the above in part recited Letters
Patent, so constructing bridges of rail or other road-ways that they shall be
capable of being lowered and withdrawn beneath the general level.
In witness whereof, I, the said James Brunlees, have hereunto set my hand
and seal, this Twenty-sixth day of December, in the year of our Lord
One thousand eight hundred and fifty-four.
JAMES BRUNLEES. (..s.)