IMPROVEMENTS IN THE MANUFACTURE OF DREDGING BUCKETS."
Year: 1880

page_text: LETTERS PATENT to Robert Hadfield, of Bloomsbury, in the County of
Middlesex, for an Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
DREDGING BUCKETS."
PROVISIONAL SPECIFICATION left by the said Robert Hadfield at the Office
of the Commissioners of Patents on the 8th December 1880.
ROBERT HADFIELD, of Bloomsbury, in the County of Middlesex. " IMPROVE-
MENTS IN THE MANUFACTURE OF DREDGING BUCKETS."
This Invention has for its object improvements in the manufacture of that
class of buckets known as dredger buckets.
Hitherto such buckets have been built up of wrought iron and rivetted together,
while the heads of such rivets were not only extremely liable to oxidise and
otherwise wear away, but to work loose and drop out at the same time that they
promoted friction, and materially lessened the holding capacity of the bucket.
Now my Invention consists in casting such buckets in steel which has heretofore
been impracticable, and I make such buckets of any ordinary size and form.
The advantages of such improved method of manufacture of dredger buckets are
numerous. In consequence of the denseness and homogeneity of the steel, buckets
so cast are not only lighter, but possess double the strength of an ordinary
composite dredger bucket built up of the best wrought iron and rivetted together,
as herein before mentioned, besides which the holding capacity of my improved steel
bucket is considerably increased, owing to there being no projecting rivet heads
either outside or inside, thus greatly reducing friction.
In addition to this owing to my improved steel bucket being cast in a single
homogeneous piece, it has a far smoother wearing surface than the ordinary bucket,
and owing to the reduced friction induced thereby, as also to its density and
perfect homogeneity, it becomes far more durable, and is practically rendered
indestructible by ordinary usage.

page_text: In pursuance of
Дебьего Ialen ше
by the said Robert Hadfield in the Great Seal Patent Office on the 3rd June
1881.
"
ROBERT HADFIELD, of Bloomsbury, in the County of Middlesex. IMPROVE-
MENTS IN THE MANUFACTURE OF DREDGING BUCKETS,"
This Invention has for its object improvements in the manufacture of dredging
buckets.
Hitherto such buckets have been built up of wrought iron and rivetted together,
thus rendering their manufacture both laborious and costly. The heads of the
rivets are also extremely liable to oxidise and wear away, and to work loose and
drop out, while they promote friction, and materially lessen the holding capacity
of the bucket.
These various disadvantages I obviate by casting such dredging buckets in steel,
which has heretofore been impracticable. To effect this I take a mould or casting
box of any suitable shape and size, and made either of sand or composition, or
partly of metal and partly of sand, or of any other suitable composition. The
interior of the mould is so constructed as to form a space or matrix of the required
shape, into which I run, pour, or otherwise introduce molten steel of any suitable
quality and temper, and so form a steel dredging bucket. The steel employed
may be either hard, soft, or medium steel, made either by the crucible, Bessemer,
Siemens, or other similar process. When the bucket is so cast I allow it to cool,
after which I take it out of the mould and carefully anneal the same, thus greatly
improving the strength and tenacity of the bucket, which is then ready for use.
Such buckets may be cast of any ordinary size and form.
The advantages of this improved method of manufacture are numerous.
Firstly. I considerably economise the labour and cost of manufacture, while the
article produced is far superior to any dredging-bucket hitherto in use.
Secondly. In consequence of the denseness and homogeneity of the steel,
dredging buckets so manufactured are not only lighter, but possess double the
strength of the ordinary composite dredging bucket, even when built up of the
best wrought iron and rivetted together, as before mentioned.
Thirdly. The containing capacity of my improved steel dredging bucket is
considerably increased, there being no projecting rivet heads therein either outside
or inside.
Fourthly. Owing to such improved steel dredging bucket being cast in a single
homogeneous piece, as also to the absence of all rivet heads as before mentioned,
it has a far smoother wearing surface than the ordinary dredging bucket, thus
greatly reducing the friction, and this together with its density and perfect
homogeneity render it far more durable and practically indestructible by ordinary
usage.
Fifthly. It affords great facility for repairing the bucket inexpensively and
effectually, as the links cast on the bottom thereof can when worn in the holes
be steel bushed in the ordinary manner; also, the lip of the bucket can be made
good when necessary by attaching a piece of hard steel thereto.
In the accompanying Drawings Figure 1 shews a front elevation, Figure 2 an
end view, and Figure 3 a side elevation of one of my improved cast steel dredging
buckets; a indicates the links, and b the body of the bucket.
Having thus described the nature of my said Invention, and the manner of
carrying the same into effect, I would here observe that I wish it to be understood
that I do not confine myself to casting my improved dredger bucket in steel only,
as I may cast the same in iron or any other suitable metal; what, I claim as my

page_text: Invention is, producing a dredging bucket of increased containing capacity,
durability, and lightness, by casting the same in steel, iron, or other suitable
metal, substantially in the manner and for the purposes hereinbefore described
and illustrated.
In witness whereof, I, the said Robert Hadfield, have hereunto set my hand
and seal, this Thirty-first day of May, in the year of our Lord One thousand
eight hundred and eighty one.
ROBERT HADFIELD. (L.S.)