Year: 1885

page_text: the following statement :-
(t
Our invention relates to the class of dredging machines of the type known as
suction-dredgers."
Our invention consists in the novel construction of the cutter by which the
material is disintegrated; in the novel' means by which the cutter is driven or
operated, and in an adjustable suction-pipe, and in the novel use and arrangements
of the spuds.
Referring to the accompanying drawings:
Figure 1 is a side elevation of our dredger.
Figure 2 is a cross-section of the cutter taken through line X X Fig. 3.
Figure 3 is a longitudinal section of the cutter taken through line Y Y Fig. 2.
Figure 4 is a side elevation of the cutter.
Figure 5 is a detail of the gear for driving the lay shaft.
Figure 6 is a detail view, showing the method of using the spuds.
A is the scow, and B is the cutter.
This consists, as shown in Figure 3, of an
inner drum b, which has a reservoir 61. On the inner drum is the outer drum b³,
having the series of buckets b³, which as shown in Figure 4, are perforated and
extend the entire length of the face of the outer drum.
They may be arranged in straight lines across the face of the drum, or as shown
in Figure 4, they may be set spirally, or at an angle, or in any combination of
straight and curved lines.
In some cases the edges of the buckets, as shown in one instance in Figure 4,
may be broken or serrated.
Upon the end of the outer drum are small buckets b', which communicate with
the reservoir, b¹. C is the suction-pipe, the inboard end of which communicates
with a suitable pump.
Its outer end communicates with the reservoir of the cutter. This pipe is con-
nected with the scow by a ball and socket-joint D, which may be made by the cap
or casing d enclosing a ball, on a short pipe d'. Upon the suction-pipe is rigidly
fixed a sleeve c, which telescopes in the short pipe d', whereby the suction-pipe

page_text: may have a longitudinal adjustment. It thus bas freedom of motion radially in
all directions within certain limits, and has also a freedom of motion axially.
E is a trussed boom pivoted to the cutter at e. This boom, while directing the
movement of the cutter, serves also as a support for the lay shaft F, which drives
the cutter. The inner end of the lay shaft bas power transmitted to it by the
following mechanism:
The pinion G on the driving shaft of the engine H, meshes with a spur gear-
wheel I, loose on a fixed intermediate shaft J. On this shaft is pivoted a sleeve K,
from which a shaft L extends at right angles to the shaft J.
On the spur-gear I is rigidly secured a bevel-pinion M, which gears into the idler
bevel-wheel N, which is loosely mounted on the shaft L; this bevel-wheel drives
the bevel-pinion on the lay shaft F. The rear end of the trussed boom is
pivoted on the shaft L as shown. This combination of wheels and shafts allows
the cutter to be moved in all directions radiating from the centre of the system.
The outer end of the lay shaft is provided with a pinion f¹, which meshes with
an internal gear f2 on the outer drum 6 of the cutter. The inner drum is so
mounted upon the end of the suction-pipe, that it may have a rotary adjustment,
which is effected by means of the gear h, the pinion h¹, (Figure 2,) on a shaft h³,
(Figure 4,) which extends inboard and may be provided with suitable hand-gear
and locking mechanism, so contrived that when locked, the drum is incapable of
motion on its axis..
The trussed boom, the suction-pipe, and the cutter, are swung from a derrick O;
and by suitable hoisting apparatus are lowered into position for work, or raised for
adjustment or repairs.
The necessity for the radial and axial movements of the suction-pipe will be
readily perceived by the dotted lines in Figure 1. The trussed boom and lay shaft
moving on a centre distinct from the centre of movement of the suction-pipe,
renders it necessary that said pipe should have an axial adjustment; while the
lateral adjustment or movement in a horizontal plane of the trussed boom neces-
sitates the radial movement of the suction-pipe.
The perforations in the buckets 63 of the cutter afford unusual facility for the
discharge of the material taken into them, because of preventing any vacuum being
formed behind it. Moreover, the water passing through the perforations will cause
a rapid and complete discharge of the material into the reservoir.
By extending the bucket the whole length of the drum, it not only reaches the
greatest area in cutting, but avoids the friction which is encountered by and
between the detached buckets of an ordinary dredger-cutter.
The spiral-set of the bucket is advantageous by reason of being able to cut into
the material to which it is applied to greater depth as it progresses, causing the
whole of the cutter to be held firmly down to the material being cut.
The serrated or irregular edge which may be given to the buckets, effect by
reason of presenting a series of points on the line of first contact, the softening
and detaching of the material attacked by the inflowing water before the full edge
of the bucket has entered the material in place. The improvement to the cutter
effected by the movable inner drum, results from its movable adaptation to the
area of discharge of material from the buckets in the reservoir, whereby it is
enabled to regulate the proportions of material or water supplied through the
buckets in such a manner that the proportion of either water or material may be
increased or diminished to any desired extent. On the sides of the scow there are
at each corner, both forward and back, a series of spuds P; these pass through
slotted guides p which are divided transversely and centrally by a piece p¹, so that
a slot defining the limits of motion of the scow is made for each spud. There are
two spuds at each corner, and the object in view is to save time in operating the
dredger.
Our method is as follows; and is shown particularly in Figure 6.
Let us suppose the spud has just completed a cut and is ready to make a forward

page_text: The forward spud of each set has just been hoisted, and the scow will now pull
abead the distance from one end of the back slot to the other, guided by the spuds
still in place.
When the scow has reached that point indicated by the dotted lines, the rear-
most spud of each set will be wedged, as shown at Q, and the operation of cutting
the material proceeds, during which the front spud of each set will be carried
forward to the extreme end of its guide-slot and will be there dropped into position
and wedged to hold the scow, while the other spud is hoisted and carried into
position, ready to drop as soon as the scow has taken up a new position,
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is
1. A rotary cutter for a suction dredging machine, having an inner drum with
a reservoir communicating with the suction-pipe, and a rotating outer drum with
buckets on its face, said buckets being perforated and arranged across the entire
face of the drum, in a straight, or spiral, or inclined, or other course, and having
their edges straight or serrated as desired; substantially as herein described.
2. A suction dredger-cutter, comprising an outer rotating drum carrying buckets
upon its face, and an inner drum on which the outer drum rotates, and having
a reservoir communicating with the suction-pipe, said inner drum being adapted to
have a rotary adjustment, substantially as herein described.
3. In a dredger, a rotary cutter adapted to be adjusted through arcs in vertical
and horizontal planes, in combination with a suction-pipe communicating with the
cutter and adapted to have an axial or longitudinal adjustment, and to move
radially to accommodate itself to the movements of the cutter, substantially as
herein described.
4. In a dredger, a rotary cutter, a boom supporting and directing the cutter, and
pivoted to the scow of the dredger, and adapted to be adjusted through arcs in
vertical and horizontal planes, a lay shaft on the boom connected at its outer end
with and driving the cutter through suitable gears, and a series of gears and shafts,
by which power is transmitted from the engine to the inner end of the lay shaft,
in combination with a suction-pipe communicating with the cutter, and having
adjustments adapting it to accommodate itself to those of the cutter, substantially
as herein described.
5. In a dredger, having a rotary cutter and a suction-pipe communicating there-
with, the means by which the cutter is driven and its adjustments directed,
consisting of the trussed boom pivoted at its outer end to the suction-pipe, the lay
shaft on said boom connected at its outer end by gearing with the cutter, and the
series of gears and shafts at the inboard end of the boom and lay shaft as herein
described, whereby said shaft is driven from the engine during all the adjustments
of the cutter, substantially as herein described.
6. The method of controlling the movements of a dredger-scow, consisting in
retaining it by one set of spuds, moving a second-set while the scow is so held, to
a fresh position in readiness to be dropped, then moving the scow or boat on the
first set to its fresh position, and then dropping the second set to hold the scow in
said position while the spuds of the first set are hoisted, and the operation repeated,
substantially as herein described.