Note: Descriptions are shown in the official language in which they were submitted.
~17'~053
BACKGROU~1D OF THE I~VENTlON
1. Field of the lnvention
The present invention relates to the control of
soil erosion especially on the sides of rivers, drainage
canals and riverbeds, on levees, beaches and the like. The
present invention more particularly relates to an articu-
lated erosion control system comprising a plurality of
blocks, each of which is connected to the adjacent block by
an interlocking connection provided by the blocks themselves
which interlocking connection maintains horizonal block
placement yet allows articulated movement in all directions
of the blocks with respect to one another allowing
conformation of the overall block system to the underlying
terrain.
2. General Background
Erosion of land is a problem generally accompanied
by water flow at the interface of the land and the water
such as on the side of a riverbed or on a beach. Erosion can
also occur as a result of rainfall as it proceeds through a
particular basin to the river which empties that area.
Erosion is prevented in a natural sense by the
growth of trees, grass, vegetation and the like with their
root systems functioning to consolidate the underlying soil
and prevent the mechanical erosion by both water and wind,
but mainly water.
The natural vegetation is removed purposefully in
rnany instances as when streams are channe1ized, or cleaned,
or when levees are reformed. Other times vegecation removal
and resulting erosion is natural, caused by flooding or the
3~ mechanical action of streams, rivers and generally by
natural water flow.
A
S,3
Land which has been stripped of the natural
vegetation is highly susceptible to erosion by wind and rain
since the consolidation provided by vegetation is missing.
This occurs on sloped terrain, as well as on terrain which
is flattened.
The erosion problem is compounded by the removal
of forrests, overgrazing of land, burning, construction of
highways and the like, and the channelization of streams.
Planting rapidly growing vegetation on areas which
have been stripped is sometimes successful but usually only
where the vegetation grows rapidly and extensively enough so
that the soil is protected. In areas where water is
continually flowing such as on riverbanks, the growth of
vegetation can usually not be done quickly enough to prevent
erosion. Various systems of revetment have been used to
augment or rep]ace vegetation as an erosion barrier. The art
has used loose fill barriers (riprap), continuous paving
mats (some with weep holes to relieve pore pressure) and
porous paving mats to control erosion.
"Riprap" which is known for control of erosion is
basically a barrier or coverage comprising a plurality of
large chunks of concrete (obtained, for example, in salvage
operations) which are dumped in a particular area. The
concrete chunks are usually of random size, with some so
~5 large as to no~ provide protection and washouts occur
underneath. Further, the placement is often random, not
adequately covering the subject area.
1~7Z(~53
Solid continuous paving mats of concrete are
highly costly because of the extensive amount of concrete
required, the difficulty and costs of installation, and the
problems of hydrostatic pore pressure which are created once
the concrete is in place.
Paving blocks of concrete and other materials are
known. Flexible porous concrete mats have been used as an
erosion controlling protective surface.
Different patents directed to using revetment
blocks and structures for preventillg soil erosion have been
issued. U.S. patents
242,689
306,251
314~022
541,815
572,762
984,121
994,999
1,039,579
1,162,499
1,379,440
1,597,114
-1,636,114
1,691,848
1,772,821
1,822,602
1,834,060
1,847,852
1,927,834
1,939,417
1,991,196
li7Z~53
1,993,217
2,008,866
2,047,197
2,143,461
2,159,685
2,221,416
2,295,422
2,454,292
2,577,170
2,662,343
2,674,B56
2,876,628
3,096,621
3,176,468
3,210,944
3,301,148
3,343,468
3,344,609
3,386,252
3,421,417
3,597,928
4,227,829
disclose blocks and erosion control systems.
U.S. Patent ~o. 4,227,820 discloses a device com-
prising a matrix of cellular concrete blocks, each of which
has internal passageways for cables to pass therethrough and
interconnect a matrix of concrete blocks. The free ends of
the cables are anchored into the ground after which operation
the soil is spread over the blocks to reinforce surface thus
controlling soil erosion.
2~'j3
U.S. Patent 4,~ discloses a ground covering
with adjoining plates which are clamped together by
tensioning elements extendin& through the plates and
parallel to them.
Nijdorn in U.S. Patent 3,922,865 describes a
mattress having a filter cloth with metal bars woven
thereinto. Spaced concrete blocks are connected to these
bars.
Appelton in U.S. Patent 3,903,702 teaches the use
of a revetment structure with similar interfitting units
which form a flexible mattress. The units are provided with
a series of interconnected ribs which make opposite sides of
the units reflections of each other.
U.S. Patent 3,597,928 discloses the use of porous
flexible supporting sheets with mat of blocks which are
placed on these sheets. Each mat consists of a plurality of
blocks with drainage passageways thcrethrough and the blocks
are secured to the sheets by adhesive means.
Nelson in U.S. Patent 3,386,252 discloses a riprap
structure for waterways, comprising rectangular blocks
interconnected by a rod which extends through the blocks to
provide for hooking the blocks at diagonally opposite corner
ends and forming a matrix.
Dixon, U.S. Patent 2,876,628 discloses a rapidly
sinking articulated revetment for riverbanks comprising
rigid blocks interconnected by flexible cables. The upper
surface of each block has recesses from which openings
extend through the whole block to provide for water
passageways.
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1~7;2()S3
Louckes in U.S. Patent 2,674,856 teaches the use
of a similar flexible revetment mat which flexibility comes
fro~ the use of reinforced wires extending continuously from
one concrete block to another to form a mattress for
protection of river banks from erosion.
U.S. Patent 2,159,685 describes a concrete riprap
consisting of precast units connected by interlocking bars
which pass through the orificcs in thc body of each unit.
A revetment in U.S. Patent 2,008,866 comprises a
number of rectangular concrete blocks arranged diagonally
and hooked together by crossed rods to form a mat.
Mason in U.S. Patent 1,987,150 teaches the use of
a revetment containing filled asphalt in a certain
proportion. A mat of such asphalt is p~aced adjacent a
mattress consisting of slabs interlocked by cables or clips
passed through the rings at each corner of a slab.
U.S. Patent 1,359,475 describes a seawall
construction comprising concrete panels with mating tongues
and groovcs at their edgcs and lockcd Logether b~y metal rods
passing through the notches in the tongues and grooves.
Edinger in U.S. Patent 1,164,708 discloses an
enbankment protection construction composed of interlocking
rectangular concrete slabs with integrally made hook flanges
and interengaging keys and sockets for locking the slabs in
a mattress.
Edinger's U.S. Patent 1,164,707 discloses a
flexible concrete slab revetment construction composed of
concrete slsbs with in-egrally formed concrete joincs
interlocking the slabs, these .slabs bcing preferably of a
triangular contour.
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U.S. Patent 763,171 teaches the use of enbankment
linings consisting of brick or stone blocks interlocked by
wires passing through the perforations in the block bodies.
Villa in U.S. Patent 554,354 discloses a covering
for protecting banks from erosion, this covering comprising
cement or terra-cotta prismatie plates interconnected by
wires which pass through the plates to form rows of units
adapted to cover riverbeds and banks, and free ends of wires
are fastened to trees or piles driven into the bank.
Flexible mats, though generally more expensive
than riprap or continuous paving barriers, are usually more
stable. Flexible mats are not as prone to under-cutting
erosion, by water, and provide greater relief for hydro-
static pressure. Flexible mat.s do cxhihit failure, however,
when individual elements of the mat are displaced by
hydrostatic pressure or wave action, for example.
Applicant has provided an improved flexible mat
structure which relieves hydrostatic pressure, conforms to
the underlying surface, and retains its structural
integrity. The noted advantages may be achieved at a cost
which is competiLive to known structures.
3. General Discussion of the Present Invention
. The present invention provides a lock block and
key block system which allows arLiculated connections to be
formed between che lock block and the key block so that a
mat of the key blocks and lock blocks can be formed in the
field by the interlocking of the blocks themselves without
extraneous connectors, wires, cables, and the like. A mat
formed with the preferred embodiment of the apparatus of the
present invention retains its interlocking integrity even
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after temporary connections which might be used in placement
of a mat assembly have been eroded or corroded away. The
preferred embodiment provides at least a lock block having
sockets spaced around about the periphery thereof which can
be connected in two radial directions to an adjacent pair of
blocks. The connection between blocks is provided by a
socket on one block and an enlarged head on the adjoining
block which occupies the socket and allows the two blocks to
articulate with respect to one another in a pivotal fashion.
The sockets and locking heads provide narrowed portions
which discourage disassembly by horizontal movement once the
blocks are in the position. Sidewalls of the sockets and
locking heads can be bevelled to allow for the surfaces of
adjoining blocks to form anglcs with respect to one another
as when the blocks occupy a curved contour, dome, valley, or
like irregularity in terrain.
In the preferred cmbodiment, the lock block is
hexagonal having rounded sockets outcropping on three of the
peripheral sides. The remaining two sides can have
immediately inside their surface vertical openings or
passageways which might allow for hydraulic flow, the
passage of vegetation, and the accumulation of soil and
silt.- The key block in the preferred embodiment is a
three-armed key block having a central hub with three
locking arms projecting radially (preferably
equi-radially-spaced) with enlarged locking heads being
provided at the tip of each arm. The center of each locking
head and the center of each locking arm form respectively
equilateral triangles of identical dimension on each key
3~ block and on each lock block.
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In the preferred embodiment, the equilateral
triangular geometric placement of the key block socket
centers and the lock block locking head centers insures
interlocking points of articulation between adjacent blocks.
Flexibility in each direction is provided and in an
alternative embodiment a twist-in lock assembly is provided
which allows easy assembly of adjacent blocks yet
discourages substantial vertical relative movement
therebetween thereafter which might result in disassembly.
The present invention provides an articulated
erosion control system having at least one lock block and a
pair of key blocks. The key blocks are connectable to the
lock block independently in an interlocking fashion with
each of the lock blocks, with the key block - lock block
connections being in separate directions and in an
articulated fashion. This allows multi-directional
flexibility which allows an entire mat system formed of the
blocks to conform easily to changes in terrain both with
regard to curvature and irregular size.
Thus, it is an object of the present invention to
provide a three dimensional interlocking mat assembly for
erosion control.
Still another object of the present invention is
to provide an articulated erosion control system having
flexibility in every direction.
Another object of the present invention is to
provide an interlocking mat for use in erosion control
system with the interlocking connections being spaced in an
equilateral triangular fashion.
11~2~1~i3
Still another object of the present invention is
to provide a twist-in lock for attaching adjacent blocks
which allows easy assembly but discourages disassembly due
to relative vertical movement of adjacent blocks.
5A further object of the present invention is to
provide an articulated erosion control mat system which can
be easily adapted to disposable sling type lifting and
placement.
Another object of the present invention is to
10provide an alternative wire interconnecting system for
assembling a plurality of adjacent blocks forming an overall
articulated erosion control system.
Still another object of the present invention is
to provide an articulated erosion control system useful in
15the controlling of waves at seashores, surfs, and the like.
It is another object of the present invention to
provide an articulated erosio~n control system having a
plurality of blocks which can be interconnected on sight
without the use of further connection devices than the
blocks themselves.
Stil~ another object of the present invention is
to provide an overall articulated erosion control system
which easily conforms to changes in terrain relief and
shape.
25Still another object of the present invention is
to provide an articulated erosion control system which
allows vegetation to grow through the system.
Another object of the prcsent invention is to
provide an articulated erosion control system which can use
but does not rely upon a mat or other interconnection
between adjacent blocks for its long term performance.
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1~7Z~S3
BRIEF DESCRIPTIO~ OF THE DRAWI~'GS
For a further understanding of the nature and
objects of the present invention, reference should be had to
the following detailed description, taken in conjunction
with the accompanying drawings, in which like parts are
given like reference numerals and wherein:
Figures l-lA are perspective views of the lock
block portion of the preferred embodiment of the apparatus
of the present invention;
Figures 2-2A are perspective views of the key
block portion of the preferred embodiment of the apparatus
of the present invention;
Figures 3A-3C are sequential views illustrating
assembly of the key block and lock block portions of the
preferred embodiment of the apparatus of the present
invention and further illustratill~ the wave control
embodiment of the key block portion;
Figures 4A, 4B are sectional schematic views
illustrating the bevelled sidewall portions of the key block
and lock block;
Figure 5 is a top view of the wave control cone
embodiment of the lock block portion of the preferred
embodiment of the apparatus of the present invention;
Figure 6 is a top view of the wave control cone
embodiment of the key ~block portion of the preferred
embodiment of the apparatus of the prcsent invention;
Figure 5A is a sectional view taken along lines
SA-5A of figure 5;
Figure 6A is a sectional view taken along lines
6A-6A of figure 6;
117Z053
Figure 7 is a top view of the articulated erosion
control mat system of the present invention illustrating a
plurality of key blocks and lock ~locks interconnected;
Figure 8 is a perspective view of a plurality of
key blocks and lock blocks interconnected to provide the
articulated erosion control system o the present invention
and illustrating the vertical support system portion
thereof;
Figure 8A is a perspective view of the hanger
portion of the preferred embodiment of the apparatus of the
present invention useful in the embodiment of figure 8;
Figure 9 is a section view of the preferred
embodiment of the appartus of the present invention during
lifting;
Figure 10 is a schematic vie~ illustrating lifting
of the preferred embodiment of the apparatus of the present
invention using a flexible mat to lift.
1~7Z~;?53
DETAILED DESCRIPTION OF THE PREFERRED _MBODIMENT
In figures 1 and 2 there is seen respectively the
lock block 20 portion of the preferred embodiment of the
apparatus of the present invention (Figure 1) and the key
block 50 portion of the preferred embodiment of the
apparatus of the present invention (Figure 2).
As will be described more fully hereinafter, each
block 20, 50 can be integral and blocks 20, 50 attach
together by interlocking. The blocks 20, 50 so provided
ln interlock to form an enlarged articulated mat 10 which can
be seen in figures 7-8, which mat allows articulation of the
individual blocks and some relative vertical movement, yet
maintains horizontal spacing thus allowing the mat 10 to
conform to the underlying terrain.
15The assembled articulated erosion control system
10 can be lifted (as during installation) by a spreader bar
or crane and assumes a curved position characteristic of a
flexible sheet supported at its ends (see figures 9 and 10).
Figures 1 and 2 show more particularly the
20construction of lock block 20 and key hlock 50.
In figure 1 can be seen lock block 20 which
provides upper and lower coplanar and preferably parallel
surfaces which terminate at a peripheral terminal sidewall.
A hexagonal shape is preferable with hexagonal sidewalls
2521-26 being shown in figure 1.
Three alternate sidewalls 22, 24, and 26 provide
sockets 30-32 which are open recesses at surface 20S of
block 20 as well as being open recesses at sidewalls 22, 24,
and 26 and at the bottom 20B of block 20. As will be
30described more fully hereinafter, each socket 30, 31, and 32
1~72~53
provides a place or the interlocking connection of key
block 50 thereto with three key blocks being attachable
respectively at sockets 30-32 of each lock block 20 to form
the articulated erosion control system 10 as shown in
figures 7 and ~.
The upper surface 20S of block 20 provides an
etching of radial V-shaped channels 39 and circular V-shaped
channels 40 which provide recesses that will during
operation gather soil allowing natural vegetation to grow on
the surface of block 20 further enhancing erosion control
and aesthetics.
A plurality of vertical preferably cylindrical
channels 34-37 are provided through block 20 which allow
hydrostatic flow through block 20 as well as allowing the
growth of vegetation therethrough which enhances the
anchoring of block 20 to its final position.
Figure 2 shows more particul~rly the construction
of key block 50. Key block 50 c~mprises a central hub 52
from which extend radially a plurality of spaced locking
arms 55-57 with three being shown in the embodiment of
figure 2.
Each locking arm 55-57 has attached at its
outermost tip portion to an enlarged locking head 60-62
respectively with each being slightly smaller than but
?.5 correspondingly sized ta register and fit within one of
sockets 30-32 provided on lock block 20. Vertical channels
65-67 are provided respectively through heads 60-62 to allow
fluid flow therethrough for hydraulic relief. Also
vegetation can grow through channels 65-67 to aid in
securement of block 50 to its underlying terrain. Each
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1~7ZOS3
socket 30-32 may provide at its lowermost portion an annular
rib 45 with a corresponding annular recess 68 being provided
around the bottom of each locking head 60-62. This
combination provides a stop which disallows a drop through
of locking heads 60-62 through its respective socket. This
connection is seen in figure 8 and once this assembly is
completed the upper surface 20S of block 20 and the upper
surface 51 of key block 50 would be substantially coplanar
as shown in the drawings in figure 8.
An additional feature, not shown in the drawings,
may be used to retain the assembled lock blocks 20 and key
blocks 50 joined in the desired coplanar relationship. A
flexible adhesive may be placed in the joint formed by
locking heads 60-62 and sockets 30-32, for example, at the
point of contact between annular ribs 45 and annular
recesses 68. A continuous bead may be used or the
application of adhesive could be discontinuous. Any suitable
rubber-like or flexible adhesive could be used. A
one-component polyurethane adhesive manufactured by Sika
Corporation, Lyndhurst, N.J. under the trademark SIKAFLEX
has been found to be satisfactory.
Figures 3A-3C show more particularly the assembly
of a single key block being placed into three lock blocks
20.
In the embodiments of figures 3A-3C and in those
sequential views shown, note the key block being provided as
designated by the numeral 80 with key block 50 having a wave
control cone 90 portion which extends upwardly a distance
of, for example, three times the overall height of the key
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1~72~)53
block 80 itself. Wave control cone 90 can provide a
truncated top 92 which gradually contours to meet locking
heads 95-97 with each locking head being provided with a
vertical channel 100-102. Though the wave control is shown,
in Figures 3A-3C, as a truncated cone 90, it will be
appreciated that another equivalent shape could also be
used, such as a cone, a cylinder, a pyramid, a truncated
pyramid or other polyhedron.
In the embodiment of figures 3A-3C, the axis of
each locking head 95-97 is skewed as shown in figure 4A.
This requires that the assembly of key block 80 into lock
blocks 20 be in downward and rotational (spiral) fashion
which is shown by the curved arrow 81 in figures 3A-3B.
Sockets 30-32 of lock block 20 are similarly skewed with the
inner curved sidewall 42-44 of each socket 30-32 being
angularly disposed with respect to the bottom 20B of lock
block 20. The connection betwee~n the lock blocks 20 and key
block 80 is accomplished by joining a key block 80
simultaneously to three lock blocks 20. The three lock
blocks 20 are placed in an array having the proper spacing
and key block 80 is positioned over the array and joined
thereto by a vertical helical motion, as shown in figure 3C.
To assemble an entire mat 10, two rows of lock blocks 20 are
laid out in an array similar to that shown in figure 7, a
row of key blocks 80 is then assembled into the array by
helical joining, as shown in figure 3C. An adjacent third
row of lock blocks 20 is then laid and a second row of key
blocks 80 is assembled into the lock blocks 20. Subsequent
laying of additional rows of lock blocks 20 and key blocks
80 is repeated until construction of the mat 10 is complete.
In figure 4A there can be seen a gap G which is provided due
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- r
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to the differing angular orientations of the inner curved
wall 42 of socket 30 as compared with the angular
orientation of the outer wall portion of enlarged locking
head 96. This gap G allows for adjustment when an entire mat
10 of assembled lock blocks ~0 and key blocks 50 are lifted
as shown in figures 9 and 10. Another embodiment of this
adjustable feature when the mat 10 is lifted is seen in
figure 4B where the locking head 96 of key block 50 would be
of a shorter height H2 than the height Hl of the lock block
120 with the gaps G being also shown between and arrows 110
illustrating movement of the upper portion of adjacent lock
blocks 20 toward the locking head 96 of key block 80. The
presence of the gaps G allow flexible articulated movement
of the mat l0 lo conform to thc sh;l~e of the substrate or
support on which the mat 10 is placed. The mat 10 can often
accommodate to hills, curves and depressions without the
necessity of forming special a`rrays to fill or fit within
spaces in the total array.
Figure 3C illustrate a complcted connection of key
block 90 into three lock blocks 20. Once this combined
downward and rotational connection (actually a spiral or
helical movement) is completed, it will be apparent to one
skillediin the art that vertical movement between key block
and lock block 20 will be difficult or at least
discouraged. Arrow 111 in figure 4A illustrates the problems
which locking head 96 would have in moving upwardly from
socket 30. The rotational movement as illustrated would be
easy to achieve manually upon assembly, but the same helical
movement of locking heads 95-97 would not normally be
duplicated by nature as by hydraulic action, waves or the
like to a mat 10 once it is in place. In figures S and 6 are
117~2~53
illustrated top views of the wave control embodiment 125 of
lock block 120 as well as the wave control cone embodiment
90 of key block 80.
In ~he embodiment of figures 5-6, each recess
30-32 is generally circular providing a center with an
equilateral triangle "T" being formed by passing a line
through the center of each recess and parallel to the
adjacent face 22, 24, 26. The articulated connections
between adjacent blocks 20, 50 or 20, 80 or 120, 80 would
also fall on these sides of equilateral triangles. In figure
6, T-2 designates an equilateral triangle formed by
intersecting each locking head 95-97 at its center with a
line perpendicular to the radial center line of each locking
arm 82-86. These triangles T and T-2 will have common sides
when the lock block and key block are assembled with the
interlocking connections of an entire mat forming an array
of equilateral triangles.
In figures 5A and 6A are seen sectional views
illustrating more particularly the construction of each of
lock block 120 and key block 80 with lock block 120 in
figures 5 and 5A providing a wave control cone 125 having a
truncated top 126.
Figures 7 and 8 illustrate a connected assembly 10
of articulated erosion control system 10 with a plurality of
lock blocks 20 being shown assembled with a plurality of key
blocks S0. Note that an articulated erosion control system
is formed which allows slight relative movement of the
blocks 20, 50 with respect to one another allowing it to
conform to irrcgularities in the tcrrain and allowing slight
3~ degrees of vertical and horizontal movcment bctween each
1172~3
block. While three-way locking is shown here, two-way and
four-way locking could also be used. For example, lock
blocks with four sockets and key blocks with two locking
tips could be used.
In figures 8-8A there can be seen the use of
hangers 150 which are substantially U-shaped providing
parallel side rods 151, 152 each of which is provided at its
upper portion with an eyelet 154, 155 with each eyelet
providing an opening 156 through which a suitable hanger
line 200 can be placed with a network of hanger lines being
used to interlace the provided hangers 150 in such a fashion
as to allow the entire mat to be supported as shown in
figure 9, during lifting of mat assembly 10. Alternatively,
mat 10 could be supported from below using a continuous
flexible sheet or net which would support mat 10 in a
vertical direc~ion with the interlocking connection taught
herein maintaining horizontal spacing. In Figures 7 and 10
an underlying supportive sheet (preferably perforated to
allow for fluid flow therethrough) is schematically shown as
210.
Figure 10 schematically illustrates a support
cable 160 attaching to beam B at eyelet 162 with bottom
eyelets 164, 165 also being provided with side support
cables 166, 168 which would attach to hanger line 200 and
thus support mat 10 during lifting and installation onto an
area which needs erosion control.
Since blocks 20, 50 provide themselves the
interlocking necessary to maintain the integrity and
connections of mat 10, erosion control in a particular area
3~ will be maintained even after sheet S or cable 200 with
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1~72053
hangers 150 have corroded away as occurs. Thus, the utility
of sheet S or hangers lS0 and cable 200 could be primarily
for installation, assembly, transportation and lifting, with
the interlocking mat above taught serving by itself to
control erosion and wave action.
Because many varying and different embodiments may
be made within the scope of the inventive concept herein
taught, and because many modifications may be made in the
embodiments herein detailed in accordance with the
descriptive requirement of the law, it is to be understood
that the details herein are to be interpreted as
illustrative and not in a limiting sense. The invention is
to be limited only by the scope of the claims appended
hereto.
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