IMPROVEMENTS IN OR CONNECTED WITH THE CONSTRUCTION OF DREDGER BUCKET-BACKS AND LINKS."
Year: 1880

page_text: LETTERS PATENT to Washington Bagshawe, of Newcastle-on-Tyne, for an
Invention of "IMPROVEMENTS IN OR CONNECTED WITH THE CONSTRUCTION
OF DREDGER BUCKET-BACKS AND LINKS."
PROVISIONAL SPECIFICATION left by the said Washington Bagshawe at
the Office of the Commissioners of Patents on the 16th March 1880.
"IMPROVEMENTS IN OR
WASHINGTON BAGSHAWE, of Newcastle-on-Tyne.
CONNECTED WITH THE CONSTRUCTION OF DREDGER BUCKET-BACKS AND LINKS."
The object of this Invention, which relates to improvements in or connected
with the construction of dredger bucket backs and links, is to increase the
durability of these parts of dredging apparatus in such a manner that the parts
thereof which are subject to the most wear may be easily replaced.
It is well known that the wear and tear of buckets and links form the most
expensive item in the cost of repairs in a dredger.
In the ordinary iron buckets having the links rivetted to the backs, besides the
links getting rapidly worn away by the action of the tumblers on their narrow
surfaces, the rivets also from the heavy strain they have to bear soon get loose and
wear the rivet holes larger, necessitating constant re-rivetting with rivets always
increasing in size, until the holes become too large for further rivetting, when the
bucket becomes useless before otherwise worn out.
In the ordinary cast steel bucket-back the wear, and tear of the rivets is avoided,
and the bars on the backs wear very much longer than those made of iron, but
when they are sufficiently worn by the action of the tumblers there is no
satisfactory way of repairing them, and although the bucket is in other respects
in working condition it is thereby rendered useless.
The especial object of my Invention is to overcome these objections by constructing
the bucket-backs and intermediate links in such a manner that the wear and
tear shall fall upon removable parts, and this I effect by adapting removable
wearing plates to both the buckets and the links.
This provision allows of the wearing plates when sufficiently worn away being.
easily replaced by others, rendering the bucket again in good condition, and the
large increase obtained in the wearing surfaces further renders them more

page_text: durable, thus reducing the cost of repairs to the buckets and tumblers to a
minimum.
In carrying my Invention into effect I manufacture the dredger bucket-backs
and intermediate links in cast steel or in malleable cast iron. For the ordinary
form of buckets in use the links or bars are cast onto the backs, so that there are
no rivets to give way, and instead of having the two bars or links on the back
separate they are joined together, forming a kind of hollow box girder, the wearing
surfaces of which are provided with recesses into which the above mentioned
removable wearing plates constructed of soft or hardened steel are fitted, being
secured in position close to the faces of the recesses by keys, and one or more
taper headed headed bolts, buckets of other forms being fitted in a similar manner.
For buckets and links of small size but one such wearing plate may be keyed
and bolted in position in its recess, the bolts passing through the plate and flange
of the link, but for links of large size is preferable to have two separate wearing
plates, each being similarly secured.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Washington Bagshawe in the Great Seal Patent Office on the 10th
September 1880.
OR
WASHINGTON BAGSHAWE, of Newcastle-on-Tyne. "IMPROVEMENTS IN
CONNECTED WITH THE CONSTRUCTION OF DREDGER BUCKET BACKS AND LINKS."
The object of this Invention, which relates to improvements in or connected
with the construction of dredger bucket-backs and links, is to increase the
durability of these parts of dredging apparatus by constructing them in such
a manner that the parts thereof which are subject to the most wear may be easily
replaced.
It is well known that the wear and tear of buckets and links form the most
expensive item in the cost of repairs in a dredger. In the ordinary iron buckets
having the links rivetted to the backs, besides the links getting rapidly worn
away by the action of the tumblers on their narrow surfaces, the rivets also, from
the heavy strain they have to bear, soon get loose and wear the rivet holes larger,
necessitating constant re-rivetting with rivets always increasing in size, until the
holes become too large for further rivetting, when the bucket becomes useless before
otherwise worn out.
In the ordinary cast steel bucket-back the wear and tear of the rivets is avoided,
and the bars on the backs wear very much longer than those made of iron, but
when they are sufficiently worn by the action of the tumblers there is no satisfactory
way of repairing them, and although the bucket is in other respects in working
condition it is thereby rendered useless.
The especial object of my Invention is to overcome this objection by constructing
the bucket backs and intermediate links in such a manner that the wear and tear
shall fall upon removable parts, and this I effect by adapting removable wearing
plates to both the buckets and the links.
This provision allows of the wearing-plates when sufficiently worn away being
easily replaced by others, rendering the bucket again in good condition, and the
large increase obtained in the wearing surfaces further renders them more
durable, thus reducing the cost of repairs to the buckets and tumblers to a
minimum.
In carrying my Invention into effect I manufacture the dredger bucket-backs
and intermediate links in cast steel or in malleable cast iron. For the ordinary
form of buckets in use the links or bars are cast onto the backs, as illustrated in
Figures 1 to 3 of the accompanying Sheet of explanatory Drawings, so that there are
no rivets to give way, and instead of having the two bars or links on the back
separate they are joined together, as shown, forming a kind of hollow box girder,
the wearing surfaces of which are provided with recesses into which the above
mentioned removable wearing plates 1 constructed of soft or hardened steel or
chilled iron are fitted, being secured by keys 2 in position close to the faces of the
recesses, and one or more taper headed bolts 3, or by any other suitable means,
buckets of other forms being fitted in a similar manner.
For buckets and links of small size but one such wearing plate may be keyed
and bolted or rivetted in position in its recess, the bolts or rivets passing through
the plate and flange of the link, as illustrated in Figures 4 and 5, but for links of
large size it is preferable to have two separate wearing plates, each being similarly
secured, as illustrated in Figures 6 and 7.
On the accompanying Sheet of Drawings Figure 1 represents a side view; Figure 2,
a plan view; Figure 3, an end view, partly in section through the line ab, Figure-1;-
Figure 4, a side view; Figure 5, a plan view; Figure 6, a side view, partly in section;
Figure 7, a plan view; Figures 8 and 9, transverse sections of Figure 4 through the

page_text: lines -d, ef, respectively; and Figures 10 and 11, transverse sections of Figure 6
through the lines g-h, i-j, respectively.
Having now described the nature and object of my said Invention together with
the manner in which the same is to be or may be performed or carried into practical
effect, I would remark in conclusion that what I claim as the Invention secured to
me by the herein before in part recited Letters Patent is,―
The improved manufacture and use of dredger bucket backs and links in cast
steel or other suitable material, constructed substantially in the manner herein before
described, or in such other equivalent manner as to admit of the application of
removable wearing plates, and the application of such removable wearing plates to
both bucket backs and links.
In witness whereof, I, the said Washington Bagshawe, have hereunto set my
hand and seal, this Eleventh day of August, in the year of our Lord One
thousand eight hundred and eighty.