[0001] The present invention refers to a lateral seal for collapsible dams, and in particular
to a lateral seal for collapsible dams of the type comprising at least one rigid element
hinged at one of their ends to the bottom of the waterway inside of which the dam
is arranged.
[0002] There exist known collapsible dams of the previously defined type which have as a
lateral sealing element sealing strips for example of rubber which when the rigid
element rotates around the axis on which it is arranged, slide on the surface on the
side of the waterway.
[0003] However, this type of lateral seal for collapsible dams presents the drawback of
wearing-out the sealing strips as well as of acting as a brake for the movement of
the rigid lateral element or elements hinged to the bottom of the waterway, particularly
for dams having limited overall dimensions.
[0004] The aim of the present invention is to provide a lateral seal for collapsible dams
of the previously defined type which is durable, which increases its sealing capacity
when the pressures exercised by the water on the collapsible dam itself increase,
and which can be controlled so as to provide the sealing in any raised position assumed
by the dam itself.
[0005] One object of the present invention is a lateral seal for collapsible dams of the
type comprising at least one rigid element hinged at one of their ends to the bottom
of a respective waterway, characterized by the fact of comprising ledge sealing means
on the lateral walls of the waterway.
[0006] The present invention will be better understood from the following detailed description,
made by way of a non limiting example, with reference to the attached sheets of drawings,
wherein:
- Figure 1 shows a perspective view of a collapsible dam provided with lateral sealing
means according to the present invention:
- Figure 2 shows a perspective view of a large size collapsible dam provided with
lateral sealing means according to the present invention;
- Figures 3 and 4 show in cross-section two types of sealing strips that can be associated
to the lateral sealing means according to the present invention.
[0007] In the more general idea of solution of a lateral seal for collapsible dams of the
type comprising one or several rigid elements hinged at one of their ends to the bottom
of a waterway, said lateral seam is provided by means of a ledge sealing means.
[0008] In Figure 1 there is shown a perspective view of a collapsible dam 1, provided with
lateral sealing means according to the present invention.
[0009] Said collapsible dam 1 comprises a rigid element 2, formed for example by a metallic
tank into which air can be introduced for causing it to float and to raise it with
respect to the upstream water basin 3 formed by the dam 1 itself.
[0010] Said rigid element 2 is connected along its end 4 by a hinge 6 to the bottom 5 of
the waterway.
[0011] The seal between the side edges 7 of the rigid element 2 (only one can be seen in
Figure 1) and the lateral walls 8 and 9 of the waterway, is provided by means of a
ledge sealing means.
[0012] Said ledge sealing means in the particular embodiment represented in Figure 1 and
applicable in particular to collapsible dams having limited overall dimensions, can
oscillate around an axis parallel to the axis of the hinge 6 which connects the rigid
element 2 to the bottom 5 of the waterway.
[0013] Said ledge sealing means comprises in the embodiment represented in said Figure 1,
a rigid and preferably metallic L-shaped bar lo, hinged at its end 11 to an axis parallel
t& the axis of the hinge 6. In particular, as shown in the Figure, the said two axes
can coincide.
[0014] As an alternative, said bar lo can be hinged to the bottom 5 of the waterway by means
of a ball joint (not shown in the Figures).
[0015] Said ledge sealing means comprises moreover blind threaded holes 12 present in the
lateral sides 8 and 9 of the waterway, so that bolts 13, associated to said bar lo,
can be engaged through the holes present on the side of said bar lo facing the lateral
sides 8 and 9 of the waterway.
[0016] As an alternative to blind threaded holes 12 and bolts 13 a hydraulic-jack (not shown)
can be connected to the bar lo for varying the position of said bar lo on the lateral
sides 8 and 9 of the waterway.
[0017] Said ledge sealing means lo can also be seen in detail in Figure 3, where is shown
a type of gasket that can be applied to said ledge sealing means.
[0018] In the particular embodiment shown in said Figure 3, said gasket is a labyrinth seal
14 comprising a series of staggered grooves and projections present on the facing
surfaces of the rigid bar lo and of the side edge 7 of the rigid element 2.
[0019] As an alternative to the solution shown in Figure 3, said gasket can be formed by
one or several continuous elements of elastomeric material or by one or several inflatable
seals, always of elastomeric material.
[0020] In Figure 2 there is shown a large size collapsible dam 15 for great depths, comprising
one or more rigid elements 16, connected at one of their ends 17, by a hinge 18, to
the bottom 19 of the waterway.
[0021] Said rigid elements 16 comprise air tanks 2
0, into which can be introduced air for causing them to be lifted from their seat 21
found in the bottom 19 of the waterway, which seat 21 is suitable to receive said
rigid elements 16 when the collapsible dam 15 is in its collapsed position.
[0022] A sheet 22, for example of a rubberized fabric, closes the opening that exists between
the upper lip 21' of the seat 21 and the upper edge 23 of the rigid elements 16, for
preventing any eventual sediment from settling in said seat 21, when the collapsible
dam 15 is raised.
[0023] Said rigid elements 16 are connected to each other in a water-tight manner by sealing
elements 24 formed for example by appropriate gaskets or rubberized fabrics.
[0024] The lateral seal between said rigid elements 16 and the banks 25 of the waterway
comprises ledge sealing means.
[0025] Said means comprise in the particular embodiment represented in Figure 2 a shoulder
26, projecting from the lateral bank 25 of the waterway, itself,, which is contacted
by the lateral edge 27 of the rigid element 16 adjacent to the said lateral bank 25
of the waterway.
[0026] Said ledge sealing means can comprise gaskets (see Figure 4) such as for example
one or more'continuous sealing strips 28 of elastomeric material, present either on
the surface of shoulder 26 facing the rigid element 16, or on the surface of the lateral
edge 27 of rigid element 16 facing the said shoulder 26, or on both of the said facing
surfaces.
[0027] As an alternative to said continuous sealing strips 28 there can be either a labyrinth-type
seal, such as the one shown in Figure 3, or an inflatable gasket of elastomeric material.
[0028] For collapsible dams having large dimensions and for great depths such as those represented
in Figures 2, said rigid elements 16 can be connected to the bottom of the waterway
by tie rods, so as to limit the amplitude of the raising oscillations, in order not
to stress sheet 22.
[0029] Said tie rods comprise in the particular embodiment shown in said Figure 2, chains
29 for example in two rows connected at one end to the bottom of the seat 21 and at
the other end to said rigid elements 16.
[0030] As can easily be understood from the previous descpript- ion, the lateral sealing
means for collapsible dams according to the present invention achieves the above mentioned
aims.
[0031] In fact, the solution represented in Figures 1 and 3, allows small sized collapsible
dams provided with the lateral sealing means according to the present invention, to
effect the sealing for any position assumed by the dam itself, since said ledge sealing
means can also be raised or lowered, as desired.
[0032] Moreover the collapsible dams provided with sealing means according to the present
invention increase their own sealing capacity, just as the head of water in the basin
3 upstream is increased, since the thrust that the water exercises upon the dam (see
arrow in Figure 1) is unloaded on the ledge sealing means, increasing, as a consequence,
the pressure exercised between the side edges of the rigid element and the ledge sealing
means themselves.
[0033] Moreover, since during the raising and lowering of the rigid elements constituting
the dam itself, there occurs no sliding of the sealing means and the gasket against
the surfaces, there is eliminated any wearing-out of the said sealing means and the
gaskets.
[0034] The solution represented in Figures 2 and 4 also guarantees for large dimension collapsible
dams 15 provided with sealing means according to the present invention, an efficient
seal even if the pressure that the water exercises on the dam itself, increases (see
arrow of Figure 2).
[0035] In fact, the increase in the thrust of the water also increases the pressure that
the lateral rigid elements 16 exercise against the shoulder 26 present on the banks
25 of the waterway.
[0036] Moreover the tie rods which connect the rigid elements 16 to the bottom of the seat
21 and which are received by the seat 21 if the rigid elements 16 lie on the bottom,
prevent in particular overturning of the rigid elements 16 not adjacent to the banks
25 of the waterway in case of very high water thrusts besides maintaining the sheet
22 which protects--said seat 21 free from any stress.
[0037] What is more, both the solutions represented permit the collapsible dam to support
differences in depths, even from the side where there is the hinge that connects the
rigid element of the collapsible dam to the bottom of the waterway (i.e. from the
direction opposite to that indicated by the arrows in Figures 1 and 2).
[0038] In fact, the upward thrust resulting from the air present in the air tanks of the
rigid elements, can compensate the pressure exercised on the dam by the higher water
level present on the side of the collapsible dam where said dam is hinged.
[0039] Moreover for the dam represented in Figures 1 and 3 the resistance also to great
differences in depth, opposed to those indicated by the arrows of Figure 1, can be
obtained by rendering the bar lo fast with the rigid element 2, and effecting the
seal between the bar lo and lateral side 8 or 9 of the waterway with the eventual
interpositioning of gaskets.
[0040] Although several particular embodiments of a lateral seal for collapsible dams according
to this invention have been illustrated and described, it is understood that also
included in its scope are any other alternative embodiments accessible to a technician
of this field.
1. Lateral seal for collapsible dams of the type comprising rigid elements hinged
at one of their ends to the bottom of a waterway into which the dam itself has been
placed, characterized by the fact of comprising ledge sealing means (lo or 26) in
the area of the lateral walls (8, 9 or 25) of the waterway.
2. Lateral seal for collapsible dams according to claim 1, characterized by the fact
that said ledge sealing means (lo) can oscillate around the axis (6) at which the
rigid elements (2) of the dam itself are hinged.
3. Lateral seal for collapsible dams according to claims 1 and 2, characterized by
the fact that said sealing means comprise an L-shaped bar (lo) hinged at one end blind
threaded holes (12) in the lateral walls (8, 9) of the waterway, and bolts (13) associated
to said bar engageable in said holes.
4. Lateral seal for collapsible dams according to claim 1, characterized by the fact
that said lateral ledge sealing means (26) are fixed.
5. Lateral seal for collapsible dams according to claim 4, characterized by the fact
that said ledge sealing means comprise a shoulder (26) projecting from each lateral
wall (25) of the waterway.
6. Lateral seal for collapsible dams according to claims 1, 4 or 5, characterized
by the fact that the said rigid-elements hinged at one of their ends are associated
tie rods (29) for limiting their oscillating movement.
7. Lateral seal for collapsible dams according to any of the preceding claims, characterized
by the fact that said ledge sealing means comprise gaskets (14 or 28).