Improvements in and Connected with Grabs for Excavating or Dredging.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
Improvements in and Connected with Grabs for Excavating or
Dredging.
I, FRANCIS GOULD MORONY STONEY, of Waterside Ironworks, Ipswich, in the
County of Suffolk, Engineer, do hereby declare the nature of this Invention to be as
follows, that is to say :-
My said Invention has for its object to improve the construction and action of
excavating or dredging apparatus of the kind working with a grab or kind of
bucket formed in two parts hinged together, and which can be lowered in an
open condition, be then closed to grip or enclose the materials to be excavated
or dredged, be next raised in the closed condition, and be finally opened to
deposit the raised materials in a truck or on a lighter, or otherwise as may
be desired. By the application of my Invention the closing and opening of the
grab are effected in an improved and simple but effective and powerful manner,
and in such a way as to be quite independent of the position of the grab and
of its rising or lowering movements.
My improved grab is suspended in the loop of a chain the two portions of which
pass over pulleys at the outer end of a jib to two winding barrels baving in con-
nection with them suitable gearing with engaging clutches arranged so that both
barrels can be worked together for raising or lowering the grab, or in opposite
directions for opening or closing it. In the loop of the chain there is a sprocket
wheel or chain pulley held in what may be termed the grab frame and which has the
grab itself connected to it; and when the chain barrels are turned in opposite
directions the chain makes this chain wheel rotate, but when the chain barrels are
turned both in the same direction the chain wheel acts simply as a means of attaching
the chain to the grab frame. It is by the rotation of the chain wheel, that the
opening and closing of the grab are effected, the parts by means of which the
actions are done being susceptible of considerable modification.
In one modification the chain wheel is fixed on the middle of a horizontal screw
shaft, having the part at one side right-handed and the part at the other side left-
handed. The ends of the screw shaft work in internal screws in two cross bars
jointed to two pairs of levers, which are centered at their upper ends above the
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page_text: chain wheel to the grab frame, and which have their lower ends below the chain
wheel jointed to short arms fixed to the two halves of the grab or bucket. When
the grab is closed the axis of its hinges is a little lower than the joints connecting
the grab to the levers which are then apart at their widest. When the chain
wheel and its screw shaft turn so as to draw the levers together they move the
connecting joints towards each other, causing the bottom parts of the grab to open
outwards and when the levers are moved outwards they close the grab, effecting
this operation with considerable force. The grab will grip blocks or masses which
it cannot enclose within its bucket-like shells, and it can be raised with them in
that condition.
In a second modification a combinination of toggle levers is substituted for the
screw shaft, for moving the main levers which act directly on the grab. On the
shaft of the main chain wheel small chain wheels are fixed and chains passing round
them are fixed to the joints of the toggle levers. The toggle combination consists of
four equal aru.s or levers with two joints connected to the main levers and the other
two above and below the axis of the main chain wheel. When the joints above and
below the axis are drawn inwards the main levers are pushed out and vice versa.
In the modifications described the grab is held entirely by the main levers, it may
however, as in a third modification, he hinged to a horizontal bar forming part of the
grab frame and situated below the inain chain pulley. In this modification the main
chain pulley acts (as in the second) by means of chains moved by small chain pulleys
on its shaft. There are two chains, and each has one end fixed to one half part of the
grab at what is the outer or top edge when the grab is closed, the other end of
the chain being fixed to the outer end of an arm fixed to the other half part of the
grab. When the chains are moved in the direction to pull on the parts connected
to the top edges of the grab they draw them upwards together and thereby make the
bottom parts separate and open. When the pull is made to act on the other ends of
the chains which are fixed to the arms, the action makes the grab close. The chains
pass round guide pulleys on the grab frame placed so that the chains may pass in
suitable directions to the parts of the grab.
When the grab is used in a considerable depth of water it may be desirable to apply
tension to the main chain by means of weighted pulleys round which the parts of the
chain are led between the end of the jib and the winding barrels.
Dated this Seventeenth day of February 1888.
EDMUND HUNT,
Applicant's Agent.

page_text: Improvements in and Connected with Grads for Excavating or
Dredging.
I, FRANCIS GOULD MORONY STONEY, of Waterside Ironworks, Ipswich, in the County
of Suffolk, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement, that is to say :-
My said Invention has for its object to improve the construction and action of
excavating or dredging apparatus of the kind working with a grab or kind of bucket
formed in two parts hinged together, and which can be lowered in an open condition, be
then closed to grip or enclose the materials to be excavated or dredged, be next raised
in the closed condition, and be finally opened to deposit the raised materials in a truck
or on a lighter or otherwise as may be desired. By the application of my Invention
the closing and opening of the grab are effected in an improved and simple but
effective and powerful manner, and in such a way as to be quite independent of
the position of the grab and of its rising or lowering movements.
My improved grab is suspended in the loop of a chain the two portions of
which pass over pulleys at the outer end of a jib to two winding barrels, having
in connection with them suitable gearing with engaging clutches arranged so that
both barrels can be worked together for raising or lowering the grab, or in opposite
directions for opening or closing it. In the loop of the chain there is a sprocket
wheel or chain pulley held in what may be termed the grab frame, and which has
the grab itself connected to it; and when the chain barrels are turned in opposite
directions the chain makes this chain pulley rotate, but when the chain barrels are
turned both in the same direction the chain wheel acts simply as a means of attaching
a chain to the grab frame. It is by the rotation of the chain wheel that the
opening and closing of the grab are effected, the parts by means of which the
actions are done being susceptible of considerable modification.
And in order that my said Invention and the manner of performing the same may
be properly understood I hereunto append two sheets of explanatory drawings to be
hereinafter referred to and representing by way of example various modifications of
my improved apparatus.
.
Figure, 1, on sheet, 1, of the drawings is an elevation of the grab in its closed
condition, figure, 2, is a cross-sectional elevation corresponding to figure, 1, and
figure, 3, is a cross-sectional elevation of the grab in its open position. Figures, 4,
and 5, on sheet, 2, are diagrams of modifications of the opening and closing details;
and figure, 6, is a sectional elevation of gearing for working the winding barrels. In
these drawings the same reference numerals are used to mark the same or like parts
wherever they are repeated.
In the arrangement shown in figures, 1, 2, and 3, the grab bucket has its halves or
shells, 7, shaped so as when closed to include a space which is nearly half a cylinder,
and the two shells are jointed to each other by hinges, 8, at parts of the ends of the

page_text: axis of the cylinder. The shells, 7, are fixed to two pairs of arms, 9, which are
jointed to the lower ends of two pairs of levers, 10, having their upper ends jointed to
a small frame, 11. Between the levers, 10, of each pair there is fitted so as to be able
to turn a little, a crossbar, 12, the middle of which has made across it a screw-tapped
hole to receive one end of a screw-threaded shaft or spindle, 13. The shaft, 13, has
fast on its middle a chain pulley, 14, and the parts of the screw shaft on opposite sides
of this chain pulley are one right-handed and the other left-handed; with which
arrangement the levers, 10, will be drawn together or forced apart accordingly as the
shaft is turned in one direction or the other. The grab and parts attached to it are
suspended by means of the pulley, 14, in the loop of a chain, 15, (indicated by broken
lines) the two side portions of which pass between guide pulleys, 16, on the small
frame, 11, and over two pulleys, 17, which are at the outer end of a jib which carries
the grab.
The chain ends, 15, are attached to separate winding barrels, 18, 19, figure, 6,
which can be turned together in either direction or separately in opposite directions.
The barrels, 18, 19, which are loose on a shaft, have fast to them spurwheels, 20, 21,
in gear with pinions, 22, 23, one fast and the other loose on a shaft, 24, which may be
turned by any suitable arrangement of winch gearing. The loose pinion, 23, has in
the same piece with it a bevil wheel, 25, in gear with two bevil pinions, 26, upon
radial spindles fitted to a wheel-like frame, 27, loose on the shaft, 24. On the other
side of the frame, 27, the bevil pinions, 26, gear with a bevil wheel, 28, fast on the
shaft, 24, and a clutch disk, 29, is fitted on the boss of the wheel, 28, so that it can be
moved a short distance along the shaft by means of a clutch lever. The clutch disk, 29,
is made with an internal conical surface to frictionally engage with an external
conical surface formed on the bevil wheel, 28, and with an external conical surface to
frictionally engage with an internal conical surface on a stationary piece, 30, which is
fixed to the framing of the winch; and the clutch disk, 29, engages with the bevil
wheel, 28, or with the stationary piece, 30), accordingly as it moved towards or from
the loose pinion, 23. In figure, 6, the clutch disk is shown as in gear with the bevil
wheel, 28, and will consequently rotate therewith, and as the clutch disk is made to
engage by teeth or projections with the wheel-like frame, 27, it will carry that frame
with it and as the pinions, 26, do not turn they will make the bevil wheel, 25, and
loose pinion, 23, turn in the same direction as the shaft, 24, and both barrels, 18, 19,
will consequently turn in the same direction. If the clutch disk, 29, is shifted it will
engage with the stationary piece, 30, and be thereby held stationary, and it will make
the wheel-like frame, 27, stationary. The bevil wheel, 28, will then turn the pinions, 26,
which will impart an opposite rotation to the bevil wheel, 25, and pinion, 23, and the
barrels, 18, 19, will be turned in opposite directions.
Any other convenient arrangement of gearing may be employed for driving two
winding barrels together or in opposite directions for the purpose of working my
improved grab.
When the doubled chain, 15, is by means of the winding barrels, 18, 19, worked so
as to turn the grab pulley, 14, and screw shaft, 13, in one direction this shaft will force
out the levers, 10, and make them close the grab shells, 7, as shown in figure, 2. And
when the doubled chain, 15, is worked so as to turn the screw shaft, 13, in the opposite
direction this shaft will draw together the levers, 10), and make them open the shells, 7,
as shown in figure, 3. When required the shells, 7, may be repeatedly opened and
closed again without raising the grab.
In a second modification of the opening and closing mechanism, which will be
understood from figure, 4, a combination of toggle levers, 31, is substituted for the
screw shaft, 13, for moving the main levers, 10, which act directly on the grab. On
the shaft of the main chain wheel, 14, small chain wheels are fixed and chains
indicated by dotted lines passing round them are fixed to the joints of the toggle
levers, 31. The toggle combination consists of four equal arms or levers with two
joints connected to the main levers, 10, and the other two above and below the axis of
the main chain wheel, 14. When the joints above and below the axis are drawn
inwards the main levers, 10, are pushed out and vice versâ.
8

page_text: In the modifications described the grab is held entirely by the main levers, 10, it
may however, as in a third modification which will be understood from figure, 5, be
hinged to a horizontal bar, 32, forming part of a frame, 33, and situated below
the main chain pulley, 14. In this modification the main chain pulley, 14, acts (as in
the second) by means of chains moved by smail chain pulleys, 34, on its shaft. There
are two chains, indicated by dotted lines, and each has one end fixed to one half
part or shell, 7, of the grab at, 35, which is at the outer or top edge when the grab is
closed, the other end of the chain being fixed to the outer end of an arm, 9, fixed
to the other half part or shell, 7. When the chains are moved in the directions to
pull on the parts connected at 35, to the top edges of the shells, 7, they draw them
upwards together and thereby make the bottom parts separate and open.
When the
pull is made to act on the other ends of the chains which are fixed to the arms, 9, the
action makes the grab close. The chains pass round guide pulleys, 36, on the frame, 33,
placed so that the chains may pass in suitable directions to the parts of the grab to
which they are attached.
1
When the grab is used in a considerable depth of water it may be desirable to
apply tension to the main chain, 15, by means of weighted pulleys round which
the parts of the chain are led between the end of the jib and the winding
barrels.
Having now particularly described and ascertained the nature of my said Inven-
Lion and in what manner the saine is to be performed, I declare that what I
claim is :-
1-The improved construction of dredging or excavating grabs and their actuating
mechanisin and comprising in combination a doubled raising or lowering chain with
winding gearing for working the two parts of the chain together or oppositely, and a
chain pulley in the loop of the chain and connected to the grab by parts which
close or open the grab when the pulley is turned by the chain, the parts being
arranged and operating substantially as and for the purposes hereinbefore
described.
2-The improved construction of grab shown in figures, 1, 2, and 3, of the accom-
panying drawings and consisting of two shells hinged together and opened and closed
by means of arms fixed to them and jointed to levers moved together or apart by a right-
and-left screw shaft substantially as hereinbefore described.
3-The arrangement of gearing shown in figure, 6, of the accompanying drawings,
for moving the two parts of the doubled grab suspending and actuating chain together
or oppositely substantially as herein before described.
Dated this Fifteenth day of November 1888.
EDMUND HUNT,
Applicant's Agent.