[0001] The present invention relates to a mobile weir for temporary closing of channels
and port entrances.
[0002] In greater detail, the present invention relates to a submergible mobile weir specifically
structured for being positioned in a point corresponding to a navigable port entrance
that connects a closed lagoon to the immediately adjacent open sea so as to be able,
if need be, to block the flow of water that from the sea flows towards the lagoon
and vice versa, preventing only in this case the naval traffic that passes through
the access to the port.
[0003] As is known, the level of the sea water is subject to periodic fluctuations (traditionally
referred to as tides), which, in coincidence with other atmospheric events of extraordinary
intensity, can pour into the lagoon such a large amount of water as to raise the level
of the water within the lagoon itself to such a high value as to jeopardize the static
stability of the buildings and of the building works distributed along the coast and/or
overlooking the lagoon itself.
[0004] The US patents Nos.
US-3756032 and
US-4836711 and the European patent No.
EP-0397609 propose a solution to this problem by means of the use of a submergible mobile weir
made up of a reinforced-concrete base, which extends on the seafloor of the port entrance
for the entire width of the entrance itself, and of y a series of plane rectangular
mobile floodgates, which are hinged edgewise on the reinforced-concrete base adjacent
to one another so as to occupy the entire width of the port entrance without solution
of continuity, and are able to swing with respect to the base about a horizontal reference
axis common to all the floodgates.
[0005] In greater detail, the mobile floodgates are able to swing between a lowered position,
in which the floodgates rest on the seafloor in a substantially horizontal position,
and a raised position, in which the floodgates extend in cantilever fashion from the
base in a direction substantially perpendicular to the seafloor of the port entrance
so as to emerge partially above the surface of the water and form a barrage that extends
without solution of continuity for the entire width of the port entrance so as to
prevent the passage of the water through the port entrance itself.
[0006] As regards, instead, the displacement of the mobile floodgates, swinging of the floodgates
from the lowered position to the raised position and subsequent return into the lowered
position are obtained by appropriately varying the buoyancy of the individual floodgates.
Each of the floodgates is in fact provided internally with a tank for regulation of
the position, which, in a way similar to the compensation tanks or ballast tanks present
in submarines, is designed to be filled with water and/or pressurized air so as to
be able to regulate the buoyancy of the floodgate, and the mobile weir is provided
with a system for supply of pressurized air, which, upon command, is able to send
into the tank for regulation of the position of each mobile floodgate an amount of
air sufficient to produce a buoyant force higher than the weight of the floodgate
itself so as to cause slow and progressive raising of all the mobile floodgates from
the lowered position to the raised position and the consequent constitution of the
barrage.
[0007] To facilitate installation of the individual mobile floodgates and the subsequent
maintenance operations of the weir, in the
U.S. patent No. US-4836711 and in the European patent No.
EP-0397609 there is moreover envisaged connection of each mobile floodgate to the reinforced-concrete
base sunken in the seafloor of the port entrance by means of a pair of disconnectable
hinges, each of which is made up of a fixed portion, which is stably anchored to the
reinforced-concrete base immediately on top of an internal service compartment, and
a mobile portion, which is instead stably fixed on the side of the mobile floodgate,
incorporates the hinge articulation joint, and is finally structured so as to be coupleable
to the fixed portion in a stable, but easily releasable, way, guaranteeing in any
case the necessary structural stiffness.
[0008] In greater detail, the mobile portion of the disconnectable hinge is basically made
up of a plane appendage, which extends in cantilever fashion from the side of the
mobile floodgate, an intermediate fork hinged so that it is free to turn on the distal
end of the plane appendage by means of a transverse pin perpendicular to the plane
of lie of the plane appendage itself, and finally an engagement head substantially
shaped like a truncated cone, which is rigidly fixed on the end of the trunk of the
intermediate fork.
[0009] In the case in point, in order to guarantee the necessary mechanical strength, the
engagement head of the hinge is normally made up of two circular metal plates of appropriate
thickness and of different diameter, which are set sharing one and the same reference
axis, at a pre-set distance from one another, and of a series of transverse stiffening
ribs, which are welded edgewise on the two circular plates so as to form a structure
with high stiffness. The fork of the hinge is instead constituted by a flanged metal
disk of appropriate thickness, which is designed to be fixed via bolts to the center
of the circular plate of larger diameter of the engagement head, and by two plane
metal appendages of appropriate thickness, which are welded edgewise on one and the
same face of the flanged disk so as to extend in cantilever fashion in a direction
perpendicular to the aforesaid face remaining parallel and facing one another.
[0010] The fixed portion of the disconnectable hinge is, instead, basically made up of an
anchorage platform, which is embedded in or in any case anchored to the reinforced-concrete
wall of the base, and is provided with a central seat that has a shape complementary
to that of the engagement head of the mobile portion of the hinge, and of an engagement
and clamping member, which is designed, in sequence, to engage the engagement head
of the mobile portion of the hinge and then to withhold the engagement head so that
it bears upon the central seat of the anchorage platform exerting a tensile force
of a pre-set value.
[0011] Unfortunately, since the mobile portion of the disconnectable hinge is subject to
extremely high mechanical stresses, it must be made up of pieces of high-strength
stainless steel, and must be assembled with extreme care on account of the extremely
small mechanical tolerances, verifying systematically proper positioning of each piece
and the quality of each individual weld. This need obviously results in long construction
times and wide use of high-quality material, with consequent explosion of the production
costs.
[0012] The particularly complex shape of the engagement head of the mobile portion of the
hinge does not moreover enable widespread use of automatic welders, which contributes
to a further increase in the costs of production of the disconnectable hinges. The
hourly cost of a skilled technician is in fact higher than that of automatic welders.
[0013] The aim of the present invention is hence to provide a mobile weir for temporary
closing of channels and port entrances that will be provided with disconnectable hinges
that will be more economically advantageous to produce.
[0014] According to the present invention, a mobile weir for temporary closing of channels
and port entrances is provided as specified in Claim 1 and preferably, but not necessarily,
in any one of the dependent claims.
[0015] The present invention will now be described with reference to the annexed drawings,
which illustrate a non-limiting example of embodiment thereof and which:
- Figure 1 is a schematic perspective view of a mobile weir for temporary closing of
channels and port entrances provided according to the teachings of the present invention;
- Figure 2 is a side view of a mobile floodgate used in the mobile weir illustrated
in Figure 1, with parts in cross section and parts removed for reasons of clarity;
whilst
- Figures 3 and 4 are two perspective views of a part of the disconnectable hinge illustrated
in Figures 1 and 2.
[0016] With reference to Figures 1 and 2, designated as a whole by 1 is a mobile weir for
temporary closing of channels and port entrances specifically structured for being
positioned on the seafloor F of a navigable port entrance connecting a closed lagoon
to the immediately adjacent open sea.
[0017] The mobile weir 1 essentially comprises a base 2 made of reinforced concrete or the
like, which extends at the seafloor F of the port entrance for the entire width of
the entrance itself, and a series of plane mobile floodgates or flap gates 3 of a
substantially rectangular shape, which are hinged edgewise on the base 2 adjacent
to one another so as to occupy without solution of continuity the entire width of
the port entrance, and so as to be able to swing about a horizontal axis A common
to all mobile floodgates 3.
[0018] In greater detail, said mobile floodgates 3 are able to swing around one and the
same horizontal axis A between a lowered position, in which the mobile floodgates
3 rest on the seafloor F of the port entrance in a substantially horizontal position,
and a raised position (see Figure 1), in which the mobile floodgates 3 extend in cantilever
fashion from the base 2 in a direction substantially perpendicular to the seafloor
F of the port entrance so as to emerge partially above the surface of the water and
form a barrage that extends without solution of continuity from one bank of the port
entrance to the other so as to prevent the passage of water through the port entrance
itself.
[0019] With reference to Figures 1 and 2, each mobile floodgate 3, in particular, is connected
to the base 2 by means of at least one pair of disconnectable hinges 4 (just two of
which are visible in Figure 1), which are positioned on the side of the mobile floodgate
3 so as to enable swinging of the mobile floodgate 3 about the axis A, and has a box
structure so as to form inside it at least one tank for regulation of the position,
which is designed to be filled with water and/or pressurized air so as to be able
to regulate the buoyancy of the mobile floodgate 3.
[0020] In addition to what has been said above, the mobile weir 1 is provided also with
a system for supply of pressurized air (not illustrated), which, upon command, is
able to pump within the tank for regulation of the position of each mobile floodgate
3 an amount of pressurized air sufficient to empty the aforesaid tank at least partially
of the water filling it so as to generate a buoyant force higher than the weight of
the mobile floodgate 3 itself. Said buoyant force is hence able to cause the progressive
raising of all the mobile floodgates 3 from the lowered position to the raised position
and the consequent creation of the aforesaid barrage.
[0021] With reference to Figures 1 and 2, in particular, each mobile floodgate 3 is made
preferably, but not necessarily, of corrosion-resistant metal material, and basically
comprises an internal load-bearing framework 5, which is designed to bestow upon the
mobile floodgate 3 the necessary structural stiffness, and a substantially parallelepipedal
outer box-like shell 6, which coats the load-bearing framework 5 completely so as
to form an enclosed space, which is to be filled with water and/or pressurized air
so as to function as ballast tank for regulation of the position of the mobile floodgate
3, and is moreover provided with a series of through openings 6a for taking in and
sending out the water, through which the sea water can enter and exit freely from
the box-like shell 6, i.e., from the ballast tank for regulation of the position of
the floodgate.
[0022] The load-bearing framework 5 is formed, instead, by a series of longitudinal stiffening
beams or centerings 7, which extend in a direction perpendicular to the axis A of
rotation of the mobile floodgates 3 and are moreover arranged parallel and set alongside
one another in one and the same reference plane, and by a series of reinforcement
cross members (not illustrated), each of which is designed to connect two adjacent
beams or centerings 7 rigidly to one another as well as to the box-like shell 6.
[0023] As regards, instead, the disconnectable hinges 4, each of these is made up of a fixed
portion 4a (schematically illustrated in Figure 1), which is stably anchored to the
base 2 immediately on top of an internal service compartment 2a, and of a mobile portion
4b, which is instead fixed on the side of the mobile floodgate 3, incorporates the
joint for articulation of the hinge about the axis A, and is finally structured so
as to be coupleable to the fixed portion 4a in a stable, but easily releasable, way.
[0024] In particular, with reference to Figures 2, 3 and 4, the mobile portion 4b of the
disconnectable hinge 4 comprises: an engagement head 8, which is substantially shaped
like a truncated cone, extends sharing an axis L locally perpendicular to the axis
A and is finally structured so as to be fittable in the fixed portion 4a of the disconnectable
hinge 4 in a stable, but readily releasable, way, providing at the same time a fluid-tight
coupling; a bracket 9 for connection to the floodgate, which is structured so as to
be fixed in cantilever fashion directly on the load-bearing framework 5 of the mobile
floodgate 3, in a position corresponding to the side thereof, and is provided with
a plane appendage, which extends in cantilever fashion from the side of the mobile
floodgate 3 remaining locally perpendicular to the axis A; and finally an intermediate
fork 10, which extends in cantilever fashion from the head 8, and is pivoted on the
plane appendage of the bracket 9 by means of a transverse through pin 11 sharing the
axis A so as to be able to swing freely about the aforesaid axis A.
[0025] In greater detail, in the example illustrated, the bracket 9 for connection to the
floodgate is constituted by a plane metal plate 9 of appropriate thickness and of
a substantially rectangular shape, which lies in a plane locally perpendicular to
the axis A, is provided with a through hole designed to be rotatably engaged by the
through pin 11, and finally is provided with a flanged side edge with which it is
to be bolted edgewise on the flanged end 7a of a purposely provided beam or centering
7 of the load-bearing framework 5, which projects from the box-like shell 6.
[0026] In other words, the bracket 9 is fixed to the side of the mobile floodgate 3 by means
of a rigid and disconnectable mechanical coupling.
[0027] With reference to Figure 1, the fixed portion 4a of the disconnectable hinge 4 is
instead formed by an anchorage platform 12, which is stably fixed on the base 2 and
is provided with a central seat substantially shaped like a truncated cone, which
is shaped so as to be able to receive the head 8 of the mobile portion 4b, and by
an engagement and clamping member 13, which is designed, in sequence, to engage the
head 8 of the mobile portion 4b and then withhold said head 8 so that it bears upon
the central seat exerting a tensile force of a pre-set value. The anchorage platform
12 and the engagement and clamping member 13 are both of the type known and will not
be described further.
[0028] With reference to Figures 2, 3 and 4, unlike the currently known solutions, the fork
10 is made in one piece with head 8 by means of a die-casting process.
[0029] In greater detail, the head 8 is formed by a substantially bell-shaped metal body
14, which develops sharing the axis L, and is provided with a blind internal cavity
14a, which communicates with the outside through a central opening made on one of
the two axial ends of the body, whilst the fork 10 is formed by two substantially
trapezial plane appendages 15 that extend in cantilever fashion from the roof of the
metal body 14, i.e., from the vault of the bell, until they reach the plane appendage
of the bracket 9 remaining locally parallel and facing one another and the axis L.
[0030] The two plane appendages 15 are obviously arranged on opposite sides of the plane
of lie of the plane appendage of the bracket 9 and of the midplane of the metal body
14 - said planes in the example illustrated coinciding with one another -, and are
both provided with a through hole designed to be rotatably engaged by the through
pin 11.
[0031] To obtain the necessary shape of a truncated cone, the head 8 is moreover provided
with two projecting annular flanges 16 and 17 of different diameter, which extend
in cantilever fashion from the metal body 14 at the two axial ends thereof remaining
locally coplanar to two reference planes perpendicular to the axis L.
[0032] The annular flange 16 surrounds the roof of the metal body 14, departing from which
are the two plane appendages 15, and has the side delimited by a truncated-cone surface
16a which is coaxial with axis L, and that converges towards the annular flange 17.
The annular flange 17 surrounds, instead, the axial end of the metal body 14 in which
the inlet to the internal cavity 14a of the body is made, and has the side delimited
by barrel-, or spherical-annulus-shaped toroidal surface 17a which is coaxial with
axis L. The maximum diameter of the annular flange 17 is moreover smaller than the
minimum diameter of the projecting annular flange 16.
[0033] Finally, in the example illustrated, the two annular flanges 16 and 17 are skirted
by two collars or annular skirts 18 and 19 made of high-strength material, which are
designed to come into direct contact with the walls of the anchorage platform 12 that
delimit the central seat thereof.
[0034] With reference to Figure 4, the head 8 is finally provided with an engagement plate
or bushing 20, which is provided with a central through hole 20a, shaped so as to
be engaged in a known way by the mobile stem 13a of the member for 13 engagement and
clamping of the fixed portion 4a of the disconnectable hinge 4, and is fixed in a
rigid way on the axial end of the metal body 14 in which the inlet to the internal
cavity 14a of the body is made in such a way that the through hole 20a is aligned
with the inlet to the internal cavity 14a.
[0035] In particular, in the example illustrated, the engagement plate or bushing 20 shares
the axis L, and is fixed in a rigid way on the axial end of the metal body 14 by means
of a series of anchoring bolts of a known type.
[0036] In a different embodiment, the inlet to the internal cavity 14a of the body is circular,
and is provided with a thread, whilst the engagement plate or bushing 20 is sized
so as to be screwed at least partially within the aforesaid inlet of the internal
cavity 14a.
[0037] Operation of the mobile weir 1 is similar to the mobile barriers for temporary closing
of channels and port entrances described in the patents Nos.
US-3756032,
US-4836711 and
EP-0397609, and does hence not require any further explanation.
[0038] The advantages deriving from the adoption of the disconnectable hinges 4 with the
head 8 and the fork 10 made of a single piece are considerable: thanks to the absence
of welds, the head 8 and the fork 10 of the hinge have, given the same mechanical
strength, an overall volume and weight sensibly lower than those of the disconnectable
hinges experimented up to now, enabling an unexpected reduction in the costs of production.
[0039] Notwithstanding the fact that the die-casting process is intrinsically more costly
than welding, the higher cost of the die-casting process is in fact amply compensated
for by the savings deriving from the reduction of the amount of material used for
each single piece and by the reduction of the costs of labour and handling of the
piece.
[0040] In addition, the mechanical flanged coupling between the bracket 9 of the disconnectable
hinge 4 and the beam or centering 7 of the mobile floodgate 3 enables rapid separation
of the two elements, enormously speeding up the maintenance operations.
[0041] As is known, in fact, the mobile floodgate 3 and the mobile portion 4b of the disconnectable
hinge 4 require completely different maintenance operations, which, with the adoption
of the solution described above, can be performed simultaneously in two distinct places.
In addition, the possibility of detaching from the mobile floodgate 3 the mobile portions
4b of the two disconnectable hinges 4 renders handling of the single parts much more
convenient.
[0042] The fact that the fork 10 is made of a single piece with the head 8 moreover enables
sizing of the mechanical flanged coupling between the bracket 9 of the disconnectable
hinge 4 and the beam or centering 7 of the mobile floodgate 3 so as to constitute
a preferential point of failure of the structure, on which, with relatively contained
costs of renewal, the mechanical impulsive stresses deriving from impact of a vessel
of large dimensions against the mobile floodgate 3 would be discharged.
[0043] Finally, it is clear that modifications and variations may be made to the mobile
weir 1 described and illustrated above, without thereby departing from the scope of
the present invention.
1. A mobile weir (1) for temporary closing of channels and port entrances comprising
a base (2) extending on the seafloor of the port entrance, and a series of mobile
floodgates (3) which are hinged edgewise on the base (2) adjacent to one another,
so as to be able to swing about a substantially horizontal main axis of rotation (A)
between a lowered position, in which the mobile floodgates (3) rest on the seafloor
(F) of the port entrance, and a raised position, in which the mobile floodgates (3)
extend in cantilever fashion from the base (2) in a direction substantially perpendicular
to the seafloor (F) so as to emerge partially above the surface of the water and form
a barrage designed to prevent the passage of water through said port entrance; each
mobile floodgate (3) being connected to the base (2) by means of a plurality of disconnectable
hinges (4) which are made up of a fixed portion (4a) stably anchored to the base (2),
and a mobile portion (4b) which is instead fixed to the mobile floodgate (3), incorporates
the joint for articulation of the hinge about said main axis of rotation (A), and
is finally structured so as to be coupleable to the fixed portion (4a) in a stable,
but readily releasable, way;
the mobile portion (4b) of at least one disconnectable hinge (4) comprising an engagement
head (8) structured so as to be fittable in the fixed portion (4a) of the disconnectable
hinge (4) itself in a stable, but readily releasable, manner, a bracket (9) for connection
to the floodgate, which is provided with a plane appendage (9) extending in cantilever
fashion from the side of the mobile floodgate (3), remaining locally perpendicular
to the main axis of rotation (A), and finally an intermediate fork (10) extending
in cantilever fashion from the engagement head (8) and pivoted on the plane appendage
of said bracket (9) by means of a through pin (11) coaxial to said main axis of rotation
(A);
said mobile weir (1) being characterized in that said fork (10) is made in one piece with the head (8) by means of a die-casting process.
2. Mobile weir according to Claim 1, characterized in that said engagement head (8) comprises a substantially bell-shaped metal body (14) which
develops according to a reference axis (L) locally perpendicular to said main axis
of rotation (A), and is provided with an internal cavity (14a) which communicates
with the outside through a central opening made on one of the two axial ends of the
metal body (14) itself; whilst said fork (10) is formed by two plane appendages (15)
which extend in cantilever fashion from the roof of said metal body (14) until they
reach the plane appendage (9) of said bracket (9), remaining locally parallel and
facing one another and said reference axis (L); the plane appendages (15) that form
said fork (10) being both provided with a respective through hole designed to be engaged
in a rotatable way by said through pin (11).
3. Mobile weir according to Claim 2, characterized in that said engagement head (8) also comprises an engagement plate or bushing (20) which
is centrally provided with a through hole (20a), and is fixed in a rigid way on the
end of the metal body (14) in which the inlet to the internal cavity (14a) of the
body is made so that said through hole (20a) is aligned with the inlet of said internal
cavity (14a).
4. Mobile weir according to Claim 3, characterized in that said engagement plate or bushing (20) is fixed in a rigid way on the end of the metal
body (14) by means of bolts.
5. Mobile weir according to Claim 3, characterized in that the inlet to the internal cavity (14a) of said body is circular and is provided with
a thread, and said engagement plate or bushing (20) is sized so as to be screwed at
least partially within the inlet of said internal cavity (14a).
6. Mobile weir according to any one of Claims 2 to 5, characterized in that said engagement head (8) also comprises a first (16) and a second projecting annular
flange (17) which extend in cantilever fashion from the metal body (14) at the two
axial ends thereof, remaining locally coplanar to two reference planes perpendicular
to said reference axis (L).
7. Mobile weir according to Claim 6, characterized in that said first annular flange (16) surrounds the roof of the metal body (14), departing
from which are the two plane appendages (15) that form said fork (10), and has the
side delimited by a truncated-cone surface (16a) which is coaxial with said reference
axis (L) and that converges towards said second annular flange (17).
8. Mobile weir according to Claim 6 or Claim 7, characterized in that said second annular flange (17) surrounds the axial end of the metal body (14) in
which the inlet to said internal cavity (14a) is made, and has the side delimited
by a barrel-, or spherical-annulus-shaped toroidal surface (17a) coaxial to said reference
axis (L).
9. Mobile weir according to any one of the preceding claims, characterized in that said bracket (9) for connection to the floodgate is fixed to the side of the mobile
floodgate (3) by means of a rigid and disconnectable mechanical coupling.
10. Mobile weir according to Claim 9, characterized in that said rigid and disconnectable mechanical coupling is a flanged coupling.