Improvements in and relating to Dredging Apparatus.
Year: 1894

page_text: Date of Application, 31st July, 1894-Accepted, 8th Sept., 1894
COMPLETE SPECIFICATION.
Improvements in and relating to Dredging Apparatus.
I, EPHRAIEM CHAQUETTE, a citizen of the United States of America, residing
at 160 Howard Avenue, in the City of Bridgeport, County of Fairfield, and State
of Connecticut, one of the United States of America, Mechanical 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 :-
The invention relates to dredging apparatus, and has in view the following
objects:
First, to guide the digging clams positively and at all times within suitable
ways;
Second, to greatly increase the capacity of an apparatus of this description and
to economize in the power necessary to swing the digging elements throughout their
field of operation;
Third, to do away with the unwieldy and top-heavy crane, which displaces and
often wrecks the dredging boat;
Fourth, to enable the digging element to travel and operate close to the boat,
thereby lessening all strain and preserving the stability of the boat;
Fifth, to provide an automatically operated chute to receive the dumpings from
the clams, which chute shall at all times occupy the same relative position with
respect to the guide for the digging clams;
Sixth, to provide means for receiving the dumpings from the chute and for
conveying them automatically to any suitable receptacle;
Seventh, to provide means for thinning the consistency of the dumpings by
automatically introducing water into said dumpings, whereby they may be removed
with greater facility or may be readily pumped and forced through a pipe line, so
as to be delivered at a remote point.
There are many parts of my improved apparatus which may be modified by
changes such as are within the range of ordinary mechanical skill, and I do not
therefore wish to be limited to the details of construction herein shown and
described.
In order that those skilled in the art to which my invention appertains may fully
understand its construction and operation, I will proceed to describe the same,
reference being had to the accompanying drawings which form a part of this
Specification, and in which-
Figure 1 is a vertical longitudinal sectional elevation of my improved apparatus ;
Figure 2, a horizontal section at the line a-a of Figure 1;
Figure 3, a broken sectional elevation of my improved apparatus similar to
Figure 1, but on an enlarged scale;
Figure 4, a section at the line of Figure 3, and
Figure 5, a section on an enlarged scale at the line e-c of Figure 2, and showing
respectively the position of the operating parts when the digging element is
depressed and the clams opened and closed.
Similar numbers of reference denote like parts in the several figures of the
drawings.
1 is the deck of any suitable boat, and 2 an arcuate rack bar secured to said deck
at the bow of the boat. 3 is a hollow king-bolt bolted to the deck, and 4 is a thimble
swivelled around said bolt so as to turn freely and held in position by means of a
cap 5 over the top of the bolt and bolted or otherwise secured thereto. 6 is a table

page_text: through the rear of which the thimble extends from top to bottom, said thimble
and table being rigidly secured together in any ordinary manner.
Depending from the bottom of the table are hangers 7 within which is journalled
a shaft 8 having mounted thereon pinions 9, 10. The pinion 9 meshes with the
rack 2, while the pinion 10 meshes with and receives motion from a worm (not
shown) on the lower end of a vertical shaft 11 journalled in the frame work of the
table, which shaft is revolved by means of any suitable and ordinary gearing
operated primarily from any ordinary steam-engine, A, mounted on the table.
12 are rollers, shown in dotted lines at Figure 2, journalled on the bottom of the
table in the arc of a circle and normally resting upon an arcuate track 13
immediately in front of the rack bar 2.
The forward extremity of the table extends beyond the bow of the boat, and
bolted or otherwise firmly secured to this extremity are the guide cages 14, which
extend vertically upward. Each of these cages is provided with vertical guide
ways 15 on opposite sides and within said cages are plunger frames 16 provided
with ribs 17 at their sides adapted to fit within the ways 15. 18 are the digging
clams of any suitable shape and pivoted at 19 within the bottom part of the
frames 16.
Since the cages and the parts contained and operated therein constitute duplicate
sets of instrumentalities exactly alike, I will hereinafter refer in my description to
only one of these sets. Mounted in the frame 16 is an ordinary tight cylinder 20
having ports 21, 22 (see Figure 5), at the upper and lower ends thereof, and within
this cylinder is a piston 23 whose rod 24 depends through any suitable packing
beyond the cylinder and carries at its lower end a block 25. 26 are toggle levers
whose ends are pivoted respectively, to the clams 18 and to the block 25, so that it
will be understood that when the rod is depressed the clams will be closed, while
the elevation of said rod will open the clams.
27, 28, are ducts which lead from any suitable steam, compressed air, or hydraulic
source into the ports 21 22, above and below the piston, for the purpose of actuating
the latter in the well known manner.
Extending loosely through a cross-bar 29 of the frame 16 is a vertical pin 30 to
the bottom of which is secured a housing 31, within which latter and around the
pin is a coil spring 32 confined between the bottom of the housing and the cross
bar. Secured to the top of the pin 30 is a block 33 to which is attached the cable 34
for elevating the frame. 35 are bell-cranks pivoted at 36 to the inside of the
frame 16 and at opposite sides thereof, and 37 are pawls which extend through and
are guided within sockets 38 in the sides of the frame and are capable of engaging
and interlocking with ratchet bars 39 on the inside of the cage 14. The lower legs
of the bell-cranks are loosely pivoted at 42, 43, to the upper legs of said cranks and
to the block 33 respectively.
As
When the weight of the plunger frame is sustained by the cable 34, the block 33
will be pulled upward thereby compressing the spring 32 and bringing the housing 31
into abutment against the cross-bar 29, while at the same time the rods 41 will be
elevated, thereby keeping the pawls 37 out of engagement with the ratchet 39.
soon as the digging clams strike the bottom to he dredged, the cable 34 will be
relieved and will slacken, and the spring 32 will distend, thereby lowering the rods 41
and throwing the pawls 37 into engagement with the ratchets 39 to lock the plunger
frame as against any upward movement which would otherwise be caused by the
closing of the clams 18, especially if the latter are operating in hard soil or other
substances which offers considerable resistance. This locking of the frame which
carries the digging clams has the effect of greatly increasing the daily capacity of
the dredging apparatus, since it insures a full load within the clam and moreover
renders the latter capable of successful operation in instances where the usual
digging devices would fail.
Also the opening and closing of the digging clams by the application of steam,
compressed air, or water, is a very important feature, since it insures rapidity, and
moreover, does away with the unwieldy chains heretofore used in this connection.

page_text: Of course any suitable and ordinary means may be employed for the purpose of
opening and closing the clams, and although I prefer to use the devices shown for
locking the plunger frame, still they are not essential to the operation of my present
invention and may be dispensed with.
I will not describe any particular means for controlling the supply and exhaust of
steam &c., through the ducts 27, 28, since this can be effected in various ways, all
of which are very ordinary.
From the foregoing it will be readily understood that the digging clement is at
all times confined and guided in its movements by positive means, and this enables
the digging to be effected and the dredgings to be delivered at places that are pre-
determined, and furthermore, permits of the use of automatically operated appliances
for the purpose of receiving the dumpings and conveying them to any convenient
receptacle.
44 is an elongated mud-trough secured to the frame of the table 6 and extending
at its front end close to the cage 14, while its rear end is open and overhangs any
suitable mud depository hereinafter to be explained.
The floor of this trough a little forward of the rear end thereof is provided with
a chute 45 which depends vertically and leads into any suitable pump.
Journalled within this trough at each end thereof are sprocket wheels 46, and
47 is a chain carried by said wheels and having secured thereto at intervals hoes 48,
which latter at their lowest position extend in close proximity to the bottom of the
trough.
49 is the main mud chute having its lower extremity rigidly mounted on the
rod 50 which latter is journalled between the sides of the cage. Rigidly secured
around this rod 50 is a rocker bar 51, and pivoted to the cage above the chute 49
are dogs 52, 53. The pivotal point of the dog 52 is at or about its center, as
shown at 54, which makes this dog a lever of the first class, while the pivotal point
of the dog 53 is at its outer end, as shown at 55, which makes said dog a lever of
the second class. Pivoted to the outer end of the dog 52 and to the inuer end of
the bar 51 is a connecting lever 56, and pivoted to the middle portion of the dog 53
and to the outer extremity of said bar is a connecting lever 57. From the fore-
going it will be understood that the elevation of the inner end of the dog 53 will
cause the chute 49 to be thrown inward within the cage, while the depression of
the inner end of the dog 52 will cause said chute to be thrown outward without
the cage.
These dogs are peculiarly constructed in that the dog 52 has its nose hinged to
the body as shown at 58 in such manner that such nose resists any impact from
above, but yields readily to any force applied at its underside and folds backward
out of the way, while the nose of the dog 53 is similarly hinged at 59 with the
exception that it resists any impact from below and yields to a force applied from
above. 60, 61, are flat springs secured to the bodies of these dogs and bearing
against the noses to keep the latter normally closed.
Carried by the frame 16 is a shoulder 62, which when said frame descends,
strikes the dog 52, thereby throwing the chute 49 without the cage and bringing
the dog 53 to a horizontal position. On the continued downward movement of the
frame the hinged nose of the dog 53 will yield to the passage of the shoulder 62.
When the frame ascends the shoulder will strike against the dog 53 and throw the
chute within the cage, the hinged nose of the dog 52 yielding to the shoulder
as the latter continues to move upward to its normally elevated position.
The locations of these dogs and this shoulder with respect to the cage and frame
are such that said dogs are always operated to swing the chute in its two
positions when the digging clams occupy a horizontal plane above that of the chute,
and it will therefore be readily understood that there can be no interference with
the chute, and furthermore, that the latter will always automatically assume the
position necessary to receive the dumpings from the clams.
The cable 34 is passed over the pulley 63 journalled in the top of the cage, and is
wound around the usual drum 64, which latter is operated in any well known

page_text: manner by an ordinary hoisting engine B. I will not describe this engine or any
details of the mechanism used for winding up and releasing the cable, since they
are all very ordinary and form no part of my invention.
After the dredgings have been delivered by the chute 49 within the trough 44, it
becomes necessary to get rid of them in some manner. In open water dredging
where the dumpings are to be carried away in a scow and deposited in any suitable
place, said dumpings are emptied from the open rear end of said trough into a
depository, which latter carries them into the scow. I will accordingly first
describe the devices which I employ in this last-named instance..
65 is a frame between the sides of which are journalled two series of rollers 66, 67,
the former above the latter, and between the sides at each end of this frame are
journalled square pulleys 68. 69 are buckets hinged together at their sides, as
at 70, and extending after the manner of an endless belt around the series of
rollers 66.
The lower rollers 67 afford an anti-friction support for the inverted buckets.
This bucket-carrying frame is not fixed to any part of the boat, but is usually
pivotally hung on a support 71, rising from the deck and supported at the outer
end which overhangs the boat either by the scow or by any other suitable means.
The object of the pivotal hanging of this frame is to allow for the rising and
falling of the tide, and also to allow for the change in the clevation of the support
for the frame away from the boat. For instance, in excavating for canals, the
outer end of the frame would be supported on the bank, and as the latter may be
irregular and may vary as to height, it would never do to fix this frame in a
horizontal position.
The location of this frame is such that the buckets are immediately below the
open rear end of the trough 44, and these buckets are the depositories for the
dumpings from the trough 44. Ou the shaft 72 of one of the square pulleys 68 is
a spur gear 73 which meshes with a pinion 74 carried by the shaft of any suitable
power pulley 75 operated in the usual manner from an ordinary engine C, whereby
said square pulley is revolved and the series of buckets caused to travel after the
manner of an endless belt around pulleys. This movement of the buckets will
carry the dredgings and dump them into any suitable scow.
To the shaft of the rear sprocket 46 is secured the pulley 76 which is belted up
in any usual manner to a power pulley 77 operated in any ordinary manner from
the engine A, whereby the chain 47 and hoes 48 are caused to travel continuously
through the trough 44.
The operation of my improved apparatus as hereinbefore described, is as
follows:-
:-
It will be remembered that there are two sets of digging devices and delivery
chutes, and, in order that the trough 44 may receive the dumpings from both
chutes without making such trough throughout its length of a width equal to the
combined widths of the chutes, I provide at the end of the trough at its sides flaring
wings 78 (only one of which is shown) which extend beneath the chutes throughout
their area and receive and guide the dumpings into the trough.
During the operation of digging by one set of clams the other set of clams is
dumping its contents into the trough. The chute 45 is closed when the dumpings
are to be disposed of by means of the buckets 69.
The chain 47 and buckets 69 are always in operation so that the dredgings are
being continually forced throughout the trough 44 into said buckets and thence
deposited in a scow or otherwise. It will be noticed that the chutes 49, trough 44,
and the digging elements, all swing in harmony with the table 6, so that their
relative positions in a vertical plane with respect to each other never change.
It will also be evident that the amount of time heretofore consumed in swinging
the clams around above the scow for the purpose of dumping, and back again to
digging position, is saved by the use of my apparatus, since the transfer of the
dumpings to the scow is accomplished by means independent of the digging clams,
which continue their fuuction of digging during such transfer. This is a very

page_text: important advantage, since, with a single set of my improved digging devices I can
do twice as much work in a given time as that heretofore accomplished by any
other similar apparatus.
The table which carries the digging devices is readily shifted at any time by
means of power from the engine A in the manner heretofore described, and in this
immediate connection I will say that my construction for accomplishing this result
not only does away with the unwieldy crane heretofore used, but also enables the
digging devices to travel close to the boat in their circuit of operation, thus greatly
lessening the strain on the boat incident to the use of such crane, and economizing
in the power necessary to swing the digging devices throughout their field of
operation.
It will be seen that the capacity of my apparatus is still further increased by
the provision of duplicate sets of digging devices, which work alternately and
continuously, and this is a feature hitherto unknown in apparatus of this description.
If desired, I can add more sets of these digging elements to still further increase
the capacity of my apparatus, but I prefer to use the number shown for the reason
that their capacity is sufficient for ordinary circumstances and they require a
smaller force of operators than would be required in the instance of a larger
system.
In
Heretofore it has been impracticable to operate a gang of digging clams for the
reason that each pair of digging clams must be swung from separate cranes operated
independently, and this would cause the boat to be continually displaced, and
furthermore would so rack and strain the latter as to wreck it in a short time.
my improvement, a most important feature resides in the positive guiding of the
digging devices within a stationary cage, and furthermore in dumping the contents
of the digging clams and conveying said contents into any suitable receptacle
without shifting such cage.
Instead of the trough and the devices operated therein and the travelling buckets,
I can use any other suitable means for conveying the dumpings from the chutes 49
to the place where said dumpings are finally deposited. For instance, I could
employ an inclined trough leading directly from the chutes into a scow, the gist of
my invention in this respect resting in the broad idea of automatically delivering
the dumpings from the digging clams into any suitable receptacle without shifting
or swinging said clams or the cages within which they are guided.
When not in use, the frame 65 is unshipped from the support 71 and placed in
any suitable and convenient part of the boat.
In the construction of dykes or levees, a suitable stationary support for the outer
end of the frame 65 is provided, which support may be shifted from time to time as
the boat is advanced, or said support may be in the nature of an elongated track
along which said frame may travel during the movement of the boat.
It frequently happens that an apparatus of this description is required for the
purpose of filling in or reclaiming land that is unfit for cultivation in its primary
state owing to the fact that it is submerged, or of a swampy nature, and in this
connection my improvement has great utility owing to its extreme rapidity of
operation. For accomplishing this purpose last referred to I dispense with the
frame 65 and the buckets carried thereby, and utilize instead thereof, a pumping
apparatus which receives the dredgings and forces them through a long pipe line,
which latter leads to the point at which they are to be deposited. This has
hitherto been accomplished under serious disadvantages owing to the slowness in
the operation of the digging devices and to the difficulty experienced in reducing
hard and solid dredgings to the consistency necessary for forcing through the
pump. It has heretofore been necessary to employ manual labor for the purpose
of mixing the dredgings with water in order that they might flow freely so as to
present no obstruction to their passage through the pump and pipe line, but it has
been found well nigh impossible to regulate the proper supply of water to the
dredgings, and furthermore the mixing of these two elements has been very
imperfectly performed, the result being that the deposit on the land to be

page_text: reclaimed has invariably been covered with water at the depth of from six inches
to a foot.
All these disadvantages above named are avoided by the use of my improvement,
and I will now proceed to describe the means which I employ for the purpose of
pumping and forcing these dredgings for delivery through a pipe line at a remote
point.
79 is any suitable force pump preferably located below the deck of the boat and
operated by any well known and ordinary means.
I will not describe the construction of this pump or the manner of operating it,
since they may be very ordinary and form no part of my present invention, which
latter has to do only with the proper delivery of the dredgings to the pump.
80 is a leader pipe to which the chute 45 is swivelled at 81, so that said chute
and pipe form a direct vertical passage leading from the trough 44 directly into
the pump. As before stated, any suitable cover or plug (not shown) may be used
to stop up the mouth of the chute in the bottom of the trough when the pump is
not to be used, and such cover is of course removed when the pump is placed in
operation. The chute is swivelled to the leader pipe 80 in order that the relative
position of such chute and pipe may not be changed during the swinging movements
of the table 6.
When the dredgings are of such a nature that they can readily flow through the
pump and pipe line I do not bring into operation any means for introducing water
into the trough to thin out the dredgings, and the latter, as fast as they are dumped
will be hauled along by the hoes 48 until they drop into the chute 45.
Whenever the digging devices strike hard or mucky soil which must be dug up
in cakes or lumps, the latter as soon as they fall into the trough are soaked with
water introduced through a pipe 82 into the forward end of the trough, and such
lumps or cakes are chopped up by the hoes 48 and are thoroughly mixed by the
latter with water during the passage throughout the trough to the chute 45. This
pipe 82 leads from a reservoir 83 which is automatically supplied with water in the
manner which I will now describe.
84 are shafts which are journalled in the frame of the boat in any suitable
manner and which carry square pulleys 85. 86 is an endless chain carried by
said pulleys, and 87 are cans which are secured one to every other link of the
.chain.
88 is a water tank in the bottom of the boat which is kept supplied from the
surrounding water and into which the cans 87 dip as they are carried downward.
The upper pulley 85 is so located that as the cans are carried over the same they
will empty their contents into the reservoir 83.
The upper shaft 84 is revolved by means of any suitable and ordinary connections
and appliances (not shown) operated from the engine B. 89 is a valve in the
pipe 82 and by means of which the supply of water within the trough may be
regulated according to the nature of the dredgings.
Thus it will be readily understood that only enough water will be delivered in
the trough to reduce the dredgings to a condition suitable for the passage through
the pump and pipe line.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a dredging apparatus, the combination of a pivoted horizontally supported
table capable of swinging in the arc of a circle, a vertically disposed cage secured
to the front end of said table, and the digging devices contained within and
positively guided by said cage, and means for operating said devices, substantially
as set forth.
2. In a dredging apparatus, the combination of a horizontally swinging table
carrying vertically guided digging devices, means automatically operated by said
devices for receiving the dredgings, means for elevating and lowering said devices,

page_text: and means for opening and closing the same at pre-determined times, and instru-
mentalities independent of the digging devices for conveying the dredgings
automatically to any suitable receptacle, substantially as set forth.
3. In a dredging apparatus, the combination of vertically guided and operating
digging devices, means for elevating and lowering the same, and appliances for
opening and closing them at pre-determined times, a chute automatically operated
by the digging devices for receiving the dumpings from the latter, and instru-
mentalities for conveying said dumpings to any suitable receptacle, substantially as
set forth.
4. In a dredging apparatus, a horizontally supported and swinging table carrying
the following elements, namely, digging devices positively guided in a vertical
plane, an automatically operated chute for receiving the dumpings from said
devices, and a conveyor for delivering said dumpings into any suitable receptacle,
substantially as set forth.
5. In a dredging apparatus, the combination of a pivoted horizontally swinging
table, a vertically disposed guide cage secured to the outer end of said table, a
plunger frame guided within said cage and capable of a free vertical movement
therein, digging clams pivoted in the bottom of said frame, means for opening and
closing said clams at pre-determined times, means for elevating and lowering said
frame, a chute automatically operated by said frame to swing in and out of said
cage and to be in position for receiving the dumpings from said clams when they
are opened, and means independent of the digging devices for conveying the
dumpings to any suitable receptacle, substantially as set forth.
6. The combination of the cage, the plunger frame guided therein and carrying
the digging devices, the pivoted chute, the rocker bar rigid with said chute, the
dogs pivoted to the cage and having noses which project within said cage, the
levers whose ends are pivotally connected to said dogs and rocker bar, and
the shoulder carried by the plunger frame and capable of acting against said dogs
to swing the chute in and out of said cage, substantially as set forth.
7. In combination with the automatically operated chute in which the dumpings
are delivered from the digging clams, the trough into which said chute leads
having therein a continually operating series of devices for conveying the dumpings
to any suitable receptacle, substantially as set forth.
8. In a dredging apparatus, the combination with vertically guided and operating
digging devices, of means independent of said devices for receiving the dumpings
therefrom and conveying them to any suitable receptacle, substantially as set forth.
9. In a dredging apparatus, the combination of the digging devices carried by a
table having a horizontally swinging movement, the automatically operated chute and
the trough carried by said table, and devices automatically operated within said
trough and independent of the digging devices for conveying the dumpings from
the latter to any suitable receptacle, substantially as set forth.
10. In a dredging apparatus, the combination with the digging devices and the
trough into which the dredgings are dumped, of means for introducing water within
said trough and into said dredgings, and devices for mixing said dredgings and
water and for conveying the same to any suitable receptacle, as a force pump
substantially as set forth.
11. In a dredging apparatus, the combination of the trough leading into a force
pump or other suitable receptacle for the dredgings, the chute leading into the
forward end of said trough, the digging devices, and means carried thereby for
automatically swinging said chute beneath and beyond the digging devices at pre-
determined times, instrumentalities continuously operated within said trough for
conveying the dredgings throughout the same, and means for automatically intro-
ducing water within said trough, thereby thinning the consistency of the dredgings,
substantially as set forth.
12. The combination of the arcuate rack secured to the forward extremity of a
dredging boat, the table pivoted to the deck of the boat and carrying a rotary
pinion meshing with said rack, the vertically disposed cage rigid with the forward

page_text: end of said table, the digging devices guided and operated within said cage, the
trough carried by said table and leading into any suitable receptacle for the
dredgings, the automatically adjustable chute for receiving the dredgings from
the digging devices and leading into said trough, automatically operated instrumen-
talities within said trough for conveying the dredgings to said receptacle, and means
for revolving said pinion whereby the table and the parts carried thereby are shifted
bodily but without changing their relative positions, substantially as set forth.
13. In a dredging apparatus, the combination of the hollow king-bolt, the table
pivoted around the same, the digging devices carried by the forward end of said
table, the instrumentalities for receiving and conveying the dredgings carried by
said table, and a vertical chute leading from the bottom of the conveying instru-
mentality and near the rear end thereof through said bolt into any suitable force
pump, substantially as set forth.
14. The combination of the shafts journalled within the frame of the boat at
points near the top and bottom thereof respectively, the square pulleys carried by
said shafts, the endless chain carried by said pulleys, the cans secured to the links
of said chain, the water tank at the bottom of the boat and through which said
cans are passed, and the reservoir in the upper part of the boat and into which
said cans successively empty their contents, substantially as set forth.
15. In a dredging apparatus, the combination of a pivoted horizontally supported
table capable of swinging in the arc of a circle, a vertically disposed cage secured
to the front end of said table, the series of independently operating frames carrying
the digging clams and contained within and positively guided by said cage, means
for opening and closing said clams, and means for lowering and elevating said
frames, substantially as set forth.
16. In a dredging apparatus, the combination of a horizontally swinging table
carrying a series of independently operating and vertically guided frames, the
digging clams depending from said frame, chutes automatically operated by the
latter during their upward movement for receiving the dredgings, means for
elevating and lowering said frames independently of each other, means for opening
and closing the clams at pre-determined times and instrumentalities independent of
the clams for conveying the dredgings to any suitable receptacle, substantially as set
forth.
17. In a dredging apparatus, the combination of the vertically disposed cage, the
plunger frame guided therein and carrying digging clams, and means, as a chute,
independent of the digging devices for receiving the dumpings from the latter in
their elevated position and for conveying them to any suitable receptacle,
substantially as set forth.
18. The combination of the vertically guided and operating digging clams, the
automatically operated chute independent of said clams and into which the
dumpings from the latter are delivered, the trough into which said chute leads, and
devices operating continually within said trough for conveying the dumpings to any
suitable depository, substantially as set forth.
19. In a dredging apparatus, the combination of the vertical cage, the series of
independent plunger frames operating and guided within said cage, the digging
clams depending from said frames, means for elevating and lowering the latter,
means for opening and closing said clams at the ends of the upward and downward
movements respectively of said frames, and means for receiving the dumpings from
the clams when the latter are opened at the end of the upward movements of the
frames, substantially as set forth.
20. In a dredging apparatus, the combination of the digging devices, the trough
leading into a force pump, means for delivering the dredgings from the digging
devices into said trough, instrumentalities continuously operated within the latter
for conveying the dredgings throughout the same, and means for introducing a
regulated supply of water within said trough and upon the dredgings, substantially
as set forth.

page_text: 21. In a dredging apparatus, the frame supporting the devices for removing the
dredgings pivotally hung to the deck of the boat.
22. In a dredging apparatus, the combination of the vertical cage, the plunger
frame guided and operated therein and carrying the digging devices, and means for
locking said cage and frame together when the latter is in its lowest position,
substantially as set forth.
23. In a dredging apparatus, the combination of the vertical cage supported by
the dredging boat and incapable of vertical movement, the plunger frame guided
and operated within said cage, the digging devices carried by said frame, and
appliances carried by said frame and automatically operated by the vertical
movements thereof for locking said frame and cage together when the frame is at
its lowest position, substantially as set forth.
24. In a dredging apparatus, the combination of the vertically guided and
operated plunger frame, the digging clams pivoted at the bottom of said frame,
instrumentalities carried by said frame and operatively connected to the digging
clams for opening and closing the latter, and means for operating said instru-
inentalities, substantially as set forth.
25. In a dredging apparatus, the combination of the stationary vertical cage
having ratchet bars, the plunger frame guided and operated therein, the pawls
carried by said frame and capable of being thrown into and out of engagement
with said bars, the bell cranks pivoted to the frame and loosely connected at their
lower legs to said pawl, the vertical resiliently acting lifting pin carried by said
frame and having at its upper end a block to which is secured the hoisting cable,
and the rods 41 pivotally connected to the upper legs of said bell cranks and to
said block, substantially as set forth.
26. The combination of the stationary vertical cage having vertical ratchet bars
on the inside thereof, the plunger frame guided and operated therein and carrying
at its lower end the digging clams, the vertical lifting pin extending freely through
a cross bar of said frame and being secured at its lower end below said cross bar
with a block, the coil spring within the housing and around said pin and confined
between the cross bar and the bottom of the housing, pawls carried by said frame
and capable of being thrown into and out of engagement with said ratchet bars,
bell cranks pivoted to said frame and having their lower legs loosely connected with
said pawls, rods having their ends respectively pivoted to the upper legs of said
cranks and to said block, and means, as a cable, secured to said block for operating
the frame, substantially as set forth.
27. The combination of the plunger frame and the digging clams pivoted at the
lower end thereof, the cylinder carried by said frame and having at the top and
bottom inlet ports, the piston within said cylinder and extending downwardly
therefrom and having on its lower extremity a block, the toggle levers pivotally
connected to said block and to the digging clams, and means for introducing steam
alternately into said cylinder through said ports, substantially as set forth.
28. The combination of the valve casing each having at diametrically opposite
points inlet and outlet openings and each provided with an exhaust opening leading
at right angles to the inlet and outlet openings, the block having T-shaped ports as
described and snugly fitting within said casing but capable of rotation, said ports
being disposed in planes at right angles to each other, and means for rotating said
blocks in harmony, substantially as set forth.
29. In a dredging apparatus, the combination of the vertical cage, the plunger
frame guided and operated therein and carrying the digging devices, a cable
whereby said frame is elevated and lowered, and means dependent upon the slacking
of said cable for automatically looking said cage and frame together, substantially
as set forth.
30. In a dredging apparatus, the combination of the vertical cage supported by
the dredging boat, the plunger frame guided and operated within said cage, the
digging devices carried by said frame, the cable whereby the latter is elevated and
lowered, and appliances secured in part to the cage and in part carried by said

page_text: frame and adapted to be automatically operated by the slacking of said cable to
lock said frame and cage together, substantially as set forth.
31. In a dredging apparatus, the combination of the vertical cage and plunger
frame guided and operated therein and carrying the digging devices, and
automatically operated locking devices secured in part to the cage and in part
carried by the frame for locking said cage and frame together, substantially as set
forth.
Dated this 21st don of Tu... 1001
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.