IMPROVEMENTS IN AND APPLICABLE TO DREDGING MACHINES
Year: 1875

page_text: LETTERS PATENT to Edwin Muir, of the City of Manchester, Civil
Engineer, for the Invention of " IMPROVEMENTS IN AND APPLICABLE TO
DREDGING MACHINES."
Sealed the 7th April 1876, and dated the 13th October 1875.
PROVISIONAL SPECIFICATION left by the said Edwin Muir at the
Office of the Commissioners of Patents, with his Petition, on the
13th October 1875.
I, EDWIN MUIR, of the City of Manchester, Civil Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN AND
APPLICABLE TO DREDGING MACHINES," to be as follows:-
The object of this Invention is so to construct a dredging machine
as to enable the framework which carries the buckets to be raised and
lowered at pleasure, and thus not only afford facility for adjusting the
angle at which the dredging buckets shall work, but also render such
dredging machine capable of passing beneath canal and other bridges,
and also to enter low places, which at present is impracticable. Now

page_text: this Invention consists in mounting such framework upon horizontal
trunnions working in suitable bearings, which form an axis for giving
a partial revolution to the framework, so that such framework may be
turned upon its axis, and thus be brought to approach to a parallel
line with the deck when required to pass under a bridge or other low
lying structure. The raising and lowering of this framework or turning
upon its axis being effected by a chain actuated by a crab, windlass,
or other suitable mechanism. The driving pulley which actuates the
endless chain carrying the buckets is mounted upon the trunnions, and
thus however the framework may be turned upon its axis the driving
strap does not required to be removed off the pulley.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edwin Muir in the Great Seal Patent Office
on the 13th April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWIN
MUIR, of the City of Manchester, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of October, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
ninth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Edwin Muir, Her special licence, that
I, the said Edwin Muir, my executors, administrators, and assigns,
or such others as I, the said Edwin Muir, 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 AND APPLICABLE TO
DREDGING MACHINES," upon the condition (amongst others) that I, the
said Edwin Muir, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
par-
ticularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to bo
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Edwin Muir, 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 :—
The object of this Invention is so to construct a dredging machine
as to enable the framework which carries the buckets to be raised and
lowered at pleasure, and thus not only afford facility for adjusting the
angle at which the dredging buckets shall work, but also render such
dredging machine capable of passing beneath canal and other bridges,
) and also to enter low places which at present is impracticable. Now
this Invention consists in mounting such framework upon horizontal
trunnions working in suitable bearings, which form an axis for giving
a partial revolution to the framework, so that such framework may be
turned upon its axis, and thus be brought to approach to a parallel
line with the deck when required to pass under a bridge or other low
lying structure, the raising and lowing of this framework or turning
upon its axis being effected upon a chain actuated by a crab, windlass,
or other suitable mechanism. The driving pulley which actuates the
endless chain carrying the buckets is mounted upon the trunnions,
and thus however the framework may be turned upon its axis the
driving strap does not require to be removed off the pulley.
In order that this my said Invention may be more readily understood
and carried into practical effect, I have hereunto annexed a Drawing
illustrating a dredger with my improvements applied thereto.
Fig. 1 represents a side sectional view, and Fig. 2, an end view of
so much of a dredger as is necessary to illustrate the application of my
improvements.
In both the views A is the framework supporting the buckets B,
which are carried by the endless chain C in the ordinary manner; D, D,
are trunnions secured to either side of the framework A, as illustrated,
and which trunnions are mounted in the pedestals D¹. The framework
A is thus capable of turning partially round upon such trunnions which
form an axis for the purpose, and being hollow such trunnions form the
bearings for a shaft E, which carries at one extremity the strap pulley
F, and at the other extremity a spur toothed pinion G gearing into a
train of toothed wheelwork (seen dotted in Fig. 1) for communicating
the necessary motion to the chain wheel H. It will thus be seen that

page_text: by this method of mounting the framework A may be turned to any
required angle either for the purpose of passing beneath a bridge (for
instance to the position seen dotted in Fig. 1), or for adjusting the
depth at which the dredging buckets shall operate upon the bed of the
canal or other place requiring dredging. The turning of the framework
A upon its axis being performed by preference by a crab I from the
barrels J of which chains K are connected to the framework A as
illustrated.
It will be readily apparent that this method of mounting is applicable
to existing as well as new dredgers, and that instead of hollow
trunnions solid studs or a solid metal shaft might be employed as an
axis for the framework with substantially the same effect.
Having thus particularly described and ascertained the nature of this
my said Invention together with the best methods with which I am
acquainted for carrying the same into practical effect, I wish it to be
understood that I claim constructing dredgers with the bucket frame-
work capable of turning upon an axis, as and for the purposes
herein-before described and illustrated on the accompanying Drawing..
In witness whereof, I, the said Edwin Muir, have hereunto set
my hand and seal, this Eleventh day of April, in the year of
our Lord One thousand eight hundred and seventy-six.