Year: 1888

page_text: I, CHARLES LAURENCE SMITH, of 20 Wilde Street, Dansom Lane, Hull, in the
County of Hull, Fitter, 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 :—
The buckets or grabs employed for excavating or dredging, have generally to be
worked with two operating sets of chains and gear; the one set for raising and
lowering the bucket or grab, the other set for closing together and opening apart
the two halves of the bucket or grab which are hinged to the frame suspended from
the lifting chain.
My invention has for its object to dispense with the second set of chain and gear, so
that a
single operating chain with its gear serves not only for raising or lowering
the bucket or grab but also for closing and opening its hinged halves.
I effect this by applying to the bucket or grab and its chain appliances such as
I will describe referring to the accompanying drawings.
Fig. 1 is a side view and Fig. 2 is an end view shewing a dredging bucket
suspended from the jib of a crane with appliances according to my invention for
opening and closing the halves of the bucket.
Figs. 3 and 4 shew these appliances to an enlarged scale, Fig. 3 being a vertical
section and Fig. 4 a plan on X X of the upper part of the bucket frame and the
stationary socket above it. The cross bar A' of the bucket frame A to which are
jointed the two halves B B of the bucket has mounted in it as usual the triple barrel,
on the middle part C on which is partly wound the main suspending chain D, and on
the two-side parts of which C¹ C' are wound the closing chains D¹ D'.
The main chain D passes up through a tube E at the top of the bucket frame A,
and through a socket F which is suspended by two side chains or other attach-
ments FF from the bracket G which at the end of the jib J carries the pulley H for
the main chain D. At a suitable part of the chain D I provide a link having a
projecting rounded collar d and in the lower part of the tube E I pivot two or more

page_text: triggers e e having their outer ends loaded so that they operate as pawls allowing tho
collar d to pass them as it descends, but catching this collar as it ascends. The tube E
with its triggers can be moved a little up or down. When it is held up the triggers e e
are free to catch the collar d, but when the tube E is allowed to descend, the heavy
outer ends of the triggers e e are held up by the plate a in such a position that the
collar d can ascend escaping the inner ends of the triggers. When the collar d is
prevented by the triggers e e from ascending the chain B when it is pulled up cannot
turn the barrel C and therefore cannot close the bucket which can therefore be raised
or lowered in its open condition. But when the collar d can pass the triggers e e on
pulling up the chain D it turns the barrels CCC thereby closing together the
halves of the bucket, which can therefore be raised or lowered in its closed condition.
By the arrangement described, the opening or closing of the bucket is thus made to
depend upon whether the tube E is held up or is free to descend. In order to govern
the action of the tube E it is made with a collar e¹ at its top and the socket F is
provided with two or more triggers f loaded at their outer ends which have internal
catch shoulders at A to receive a disc plate K that lies free on the top of the frame A.
The triggers owing to the weight of their outer ends, take such positions that their
inner ends escape the collar e¹ of the tube E, which is therefore free to drop. But
when the disc K is raised along with the bucket it spreads out the outer ends of the
triggers and lodges on their catch shoulders & holding the triggers in such positions
that their inner ends engage under the collar e¹ raising the tube E and thereby
causing its triggers e to engage the collar d on the chain D.
The operation with this apparatus is as follows.
The chain D being slacked out, the bucket descends open to the bottom where it
rests. The tube E being now down its triggers e e are clear of d so that on hauling
up the chain D, the first action is to turn the barrels C C¹ C' and thus to close
together the two halves of the bucket, which thereupon is raised with its contents
until the dise K approaches but does not reach the triggers f. The jib can then
be swung round to bring the bucket over the spot where its contents are to be
discharged. Then on raising the bucket sufficiently the disc K acts on the triggers f
(causing their upper ends to engage under the shoulder e¹) and is held by their
shoulders k. The chain D being then lowered the lower parts of the triggers fare
opened a little the disc K falls and the tube E being held up by the triggers while
the chain descends the bucket opens. The bucket is now swung open into the
position where it has to be lowered for dredging; it is raised a little and the collar d
catching the triggers e raises E so that the triggers f become released by their own
weight releasing E. The bucket is then lowered open until it reaches the material
which it has to raise, when the operation is repeated.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
In combination with a self closing bucket or grab for excavating or dredging,
the collar d on the main chain, the tube E with its triggers ee and collar e the
suspended socket F with its triggers and dise K, arranged and operating sub-
stantially as and for the purpose herein set forth.
Dated this 18th day of December 1888.