Improvements in Grab or Clam Dredger Buckets.
Year: 1889

page_text: Date of Application, 12th July, 1889
Complete Specification Left, 28th Nov., 1889-Accepted, 4th Jan, 1890
PROVISIONAL SPECIFICATION.
Improvements in Grab or Clam Dredger Buckets.
I EDWARD YOUNGMAN HARRISON, Master and Engineer of the steam dredger
"Zein" at present working at the Richmond River in the Colony of New South
Wales do hereby declare the nature of my said invention to be as follows:-
This invention has reference to improvements in grab or clam dredger buckets
whether for lifting silt or mud or of open construction for lifting stone and ballast
such buckets having two jaws and being worked by chains arranged to control the
closing and opening of such jaws and it has been specially devised in order that
compared with the buckets heretofore constructed the complication in working the
closing and opening chains may be considerably reduced that they may be manu-
factured of comparatively lighter material and yet retain as great strength and
that they may be used with greater success in obtaining their load and that they
may be more simple in make and in use.
These improvements in grab or clam dredger buckets will now be described in
detail by reference to the drawings in which Figure 1 is a plan of a grab dredger
bucket constructed. according to my invention and Figure 2 is a sido elevation of
same (both with chains unattached), Figure 3 is a sectional elevation, and Figure 4
is an end elevation of the same with the jaws opened and the closing and hauling
chain slack.
A and B are the jaws-C hinge bolt-D hauling and closing chain-E opening
chain. A B are central partitions-A B diagonal stays-A3 B are lugs or eyes-
A B are strengthening pieces or bars-A B are bottom teeth-Care hinge plates
or straps-D strengthening piece on partition A'-D2 shackle-D³ case or jaws
fixed to partition B-D sheave or pulley on pin D in jaws D3-D and D' cases
or jaws fixed respectively to partitions A and B and taking over bolt C-D³ is
sheave or pulley-E are slings-E junction shackle.
In operation the grab dredger bucket is slung and lowered in the position shown
in Figure 4 when chain E tightening slings E keeps the jaws A and B fully dis-
tended. To fill the bucket the opening chain E is slackened and the hauling and
closing chain D is wound up when it pulling around sheave D8 and sheave D₁ will
close the jaws A and B and when they have closed over a load will raise such load
to where required and when it is slackened chain E being tight the jaws A and B
will open and discharge the contents of the bucket.
Figures 5 and 6 are side and end elevations respectively of a modified form of
grab dredger bucket constructed according to my invention and in this case a stone
A and B are prongs or
and ballast lifter instead of a silt or mud lifter is shewn.
jaws-Chinge bolt-D hauling and closing chain-E opening chain-A3 B are lugs
or eyes A* B* (dotted) show where joints in prongs A and B might be placed.
Care lugs on hinge C-D are slings-D2 junction shackle E slings-E² rack
plate Eslings--E junction shackle. In this bucket similar operations to those
described will have like effect that is by hauling on chain E the jaws or prongs A
and B will open and become distended and by hauling on chain D the jaws or
prongs will grasp and lift a load.
Although I have shewn the preferable construction of bucket for their respective
uses it is to be understood that I might dispense with the use of sheaves or
pulleys for guiding the hauling and closing chain as explained in the first described
bucket and attach such chain to brackets on the hinge bolt as explained in last
described bucket and it is also to be understood that I do not confine myself to the

page_text: precise mechanical means by which my invention may be carried out so long as the
nature of the same be retained.
Dated this Thirteenth day of May One thousand eight hundred and eighty
EDWD. Y. HARRISON.
COMPLETE SPECIFICATION.
Improvements in Grab or Clam Dredger Buckets.
"
I EDWARD YOUNGMAN HARRISON Master and Engineer of the steam dredger
"Zeta," of "Ballina Richmond River in the Colony of New South Wales 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:-
This invention has reference to improvements in grab or clam dredger buckets
whether for lifting silt or mud or of open construction for lifting stone and ballast
such buckets having two jaws and being worked by chains arranged to control the
closing and opening of such jaws and it has been specially devised in order that
compared with the buckets heretofore constructed the complication in working the
closing and opening chains may be considerably reduced that they may be manu-
factured of comparatively lighter material and yet retain as great strength and that
they may be used with greater success in obtaining their load and that they may be
more simple in make and in use.
These improvements in grab or clam dredger buckets will now be described in
detail by reference to the drawings filed with my Provisional Specification in which
Figure 1 is a plan of a grab dredger bucket constructed according to my invention
and Figure 2 is a side elevation of same (both with chains unattached), Figure 3 is a
sectional elevation and Figure 4 is an end elevation of the same with the jaws opened
and the closing and hauling chain slack.
A and B are the jaws-Chinge bolt-D hauling and closing chain-E opening
chain. A¹ B¹ are central partitions-A2 B² diagonal stays-A³ ³ are lugs or eyes-
A B aro strengthening pieces or bars-A' B' are bottom teeth-C¹ are hinge plates
or straps D strengthening piece on partition A'-D shackle-D³ case or jaws
fixed to partition B-D sheave or pulley on pin D in jaws D³-D and D' cases
or jaws fixed respectively to partitions A and B and taking over bolt C-D³ is
sheave or pulley-E' are slings-E junction shackle.
In operation the grab dredger bucket is slung and lowered in the position shown in
Figure 4 when chain E tightening slings E' keep the jaws A and
fully distended.
To fill the bucket the opening chain E is slackened and the hauling and closing
chain D is wound up when it pulling around sheave D and sheave D will close the
jaws A and B and when they have closed over a load will raise such load to where
required and when it is slackened chain E being tight the jaws A and B will open
and discharge the contents of the bucket.
Figures 5 and 6 are side and end elevations respectively of a modified form of
grab dredger bucket constructed according to my invention and in this case a stone
and ballast lifter instead of a silt or mud-lifter is shewo. A and B are prongs or
jaws-hinge bolt-D hauling and closing chain-E opening chain-A B are lugs
or eyes-A* B* (dotted) show where joints in prongs A and B might be placed.
Care lugs on hinge C-D are slings-D2 junction shackle-E' slings-E' rack
plate Eslings-junction shackle. In this bucket similar operations to those
described will have like effect that is by hauling on chain E the jaws or prongs A
and B will open and become distended and by hauling on chain D the jaws or
prongs will grasp and lift a load.
"
Although I have shewn the preferable construction of bucket for their respective

page_text: ses it is to be understood that I might dispense with the use of sheaves or pulleys
or guiding the hauling and closing chain as explained in the first described bucket
nd attach such chain to brackets on the hinge bolt as explained in last described
bucket and is also to be understood that I do not confine myself to the precise
nechanical means by which my invention may be carried out so long as the nature of
he same be retained.
Having now particularly described and ascertained the nature of my said inven-
ion and in what manner the same is to be performed I declare that what I
claim is :-
First A grab dredger bucket having two sides, sets of jaws or prongs hinged to
a common bolt from one of which the hauling and closing chain is led around a
pulley or sheave on the other and back round a pulley or sheave on said common
bolt and from the outsides of both of which the opening chain is led substantially as
herein described and explained.
Second A grab dredger bucket having two sets of jaws or prongs or two sides
hinged to a common centre to which the hauling or closing chain is attached and to
the outsides of which jaws or prongs a bi-furcated opening chain is attached sub-
stantially as herein described and explained.
Third In a grab dredger bucket the combination and arrangement with partitions
brackets or braces within the sides or jaws of an attachment for the hauling and
closing chain and of jaws or casings for guiding sheaves or pulleys and of such
guiding sheaves or pulleys substantially as herein described and explained and as
illustrated in Figures 1 to 4 of the drawings.
Fourth In a grab dredger bucket the combination and arrangement with jaws or
prongs or two sides hinged to a common bolt of brackets or eyes on such bolt for
attachment of the hauling and closing chain of outside sling chains to a common
junction and of rack plates attached to a bifurcated closing chain substantially
as herein described and explained and as illustrated in Figures 5 and 6 of the
drawings.
Dated this First day of July One thousand eight hundred and eighty nine.
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