[0001] This invention relates to drain constructions of the kind generally used for collecting
surface water from roadways, paths or other hard paved surfaces on which water or
other liquids tend to collect.
[0002] Many drainage systems have been used including open gutters, formed by an open channel
in the surface to be drained. The channel is often formed in a series of blocks, precast
or cast in situ, arranged end-to-end. In many circumstances, however, it may be desirable
to cover such a drainage channel with some form of grating in order to prevent entry
of debris into the channel and also to provide minimum interruption to the continuity
of the surface. This is often desirable on a roadway or other surface over which foot
traffic or vehicles run. Installation of conventional drainage channels of the above-mentioned
kind is expensive, and the use of gratings is-also expensive, due to the cost of the
actual grating itself and also the cost of seatings or other fixtures in which the
grating is located.
[0003] It is the object of this invention to provide a drain construction which is effective
in use and construction as well as being inexpensive to produce and simple to install.
[0004] According to the invention there is provided an assembly for use in drain construction
characterised by an elongate, generally tubular conduit having, extending along the
length thereof, an elongate opening which is narrower than the conduit and faces upwardly
in use of the assembly, and two spaced elongate wall members connected to the conduit
along opposite sides of the opening and extending away from the opening so as to define
between them a slot communicating, through the opening, with the interior of the conduit.
[0005] Such an assembly may be installed, in a drain construction, by forming a trench in
the ground, locating the assembly within the trench with the slot defined by the wall
members facing upwardly and the upper edges of the wall members substantially level
with the surface of the ground, and then filling the trench up to ground level around
the assembly with a material, e.g. a settable material such as concrete, which is
such as to embed and support the assembly.
[0006] With this arrangement any water on the top surface of the surrounding material, or
any surrounding surface, may flow into the slot and thence down into the drainage
conduit.
[0007] Preferably, adjustable spacing means are provided between the elongate wall members.
[0008] With this arrangeme:-.-, movement in the surrounding material due to changes in temperature
can be accommodated by allowing the wall members to move apart or towards each other
as the surrounding material moves.
[0009] The adjustable spacing means may include spring means, such as a helical compression
spring, interconnecting the wall members in a manner tending to urge the wall members
apart. Alternatively, the adjustable spacing means may comprise a temperature responsive
device connected between the wall members in a manner to adjust the spacing between
the wall members in accordance with the ambient temperature. Preferably, the adjustable
spacing means are enclosed in a protective sleeve extending between the wall members.
The protective sleeve may comprise two telescoping parts which slide relatively to
one another to accommodate relative movement between said wall members.
[0010] The generally tubular conduit may be formed of flexible material so that adjustment
of the spacing between the wall members is accompanied by corresponding adjustment
of the width of the opening in the conduit, said adjustment being permitted by flexure
of the walls of the conduit.
[0011] There may be provided on each wall member a plurality of alternative locations for
attachment of the conduit thereto, whereby the depth of the slot provided between
the wall members, relative to the conduit, may be adjusted.
[0012] A location for attachment of the conduit to each wall member may be provided by at
least one longitudinally extending groove along the outer surface of the wall member
into which grooves are engageable the two edges of the conduit which define the aforesaid
opening therein. Preferably, the conduit is formed of resiliently flexible material,
such as a resilient plastics, and said edges of the conduit are retained in said grooves
by the resilience of the conduit.
[0013] The conduit may be generally circular in cross-section.
[0014] The width of the slot defined by said wall members preferably increases as it extends
towards the conduit.
[0015] The edge of each wall member remote from the conduit may be provided with an outwardly
extending flange, and each outwardly extending flange may be formed, on the surface
thereof facing away from the conduit, with spaced grooves extending transversely to,
and opening into, the slot defined by the wall members. Preferably, the bottom walls
of said grooves are inclined towards the conduit as they extend towards the slot defined
between the wall members.
[0016] A number of the assemblies may be placed end-to-end so that the slots and internal
drainage conduits are in communication.
[0017] The invention will now be described by way of example with reference to the accompanying
drawings in which:
Figure 1 is a perspective view of a drain construction arranged in accordance with
the present invention,
Figure 2 is a cross-sectional view of a spring spacer used in the drain construction.
[0018] The drain construction shown in the drawings includes an assembly comprising two
generally angle section wall members 10 and 11 and a resilient conduit tube 12. The
members 10 and 11 are preferably made from cast iron or plastics material and are
of similar section. Each is provided along its upper edge with a tapering, shorter
outwardly extending flange which is formed on its upper surface with spaced tapering
grooves 13 to give a castellated effect at the upper edge of a slot defined between
the members. This arrangement tends to dissipate energy in the flow of water across
the assembly, thus encouraging the water to flow into the slot. The grooves taper
outwardly so as to provide, in the base of each groove, a downward sloping surface
leading into the slot.
[0019] The longer flanges of the members 10 and 11 extend downwardly but slope away from
one another towards the lower ends so that the slot is of increasing width. On the
external surface of each wall member, and near the lower edge thereof, is a series
of spaced horizontal ridges and grooves 14, 15 which run lengthwise of the members
10 and 11 respectively.
[0020] The conduit tube 12, which is made from a resilient material such as, for example,
plastics material, is of generally circular configuration but with an upwardly presented
longitudinal opening. The edges of the tube which define the opening are engaged in
one of the grooves 15 in the respective wall members 10 and 11. In the construction
shown there are three such grooves 15 on each of the members and it is possible to
engage the tube edges into any chosen pair. By this means the capacity of the drain
is adjustable by regulating the depth of the slot and the cross-sectional area of
the conduit 12 in relation to the width of the slot between the two members 10 and
11. The tube 12 is conveniently made initially as a complete tube which is split and
the two sides separated in order to engage in the grooves 15 in the members 10 and
11 as shown.
[0021] To support the two members 10 and 11 and to space them apart there are a number of
spacers which are positioned at intervals along the lengths of the members 10 and
11.
[0022] Referring to Figure 2, each spacer comprises a helical compression spring 21, opposite
ends of which abut plates 18, 19 on the inner surfaces of the wall members 10, 11
respectively. The spring is located by screws 22, 23 which project through the wall
members and into the ends of the spring. It is protected against dirt and debris by
two telescopically slideable tubes 16, 17 which surround the spring 21, the ends of
the tubes being closed by the plates 18, 19.
[0023] The spring 21 permits the members 10 and 11 to move towards and away from one another
as a result of movement or expansion of the material surrounding the assembly.
[0024] In an alternative arrangement the spacers may be temperature responsive piston and
cylinder units containing fluid which is responsive to temperature change to tend
to expand the unit, so as to keep the members 10, 11 apart while allowing some relative
movement thereof.
[0025] As shown in Figure 1, in use the assembly is embedded in a body of material, indicated
at 24, such as concrete or tarmac or construction material including polymer structures.
The material is settable and provides a flat top surface. Any expansion or contraction
of this material results in movement of the members 10 and 11 towards or away from
one another and this is accommodated by the spring spacers.
[0026] Keying elements 25 are provided on the sides of the members 10 and 11 to lock them
into the settable material 24.
[0027] The method of making the drain construction comprises assembling the members 10 and
11 and the tube 12 in correct relationship, as shown, the spring spacers being inserted
at intervals along the length of the assembly. Further similar assemblies are placed
end-to-end to provide a continuous drain. Typically, each assembly may have a length
of one metre or longer. Connecting members (not shovm) in the form of sleeves surrounding
the tube 12 may be fitted to provide a water-tight or substantially water-tight seal
between adjacent lengths of the drain. In this way a complete drain, with a continuous
open slot and a continuous drainage conduit may be simply formed in minimum time.
[0028] The assemblies are placed in a prepared trench and are suspended by hooks 28 from
battens 27 which are long enough to reach datum levels in the surrounding surface.
The hooks 28 are adjustable in length, having adjustment nuts 28 engaging threads
on the upper ends thereof. The hooked lower ends engage the spring spacers already
described.
[0029] Once the assemblies are in place, the trench is back-filled with settable material
to the required level corresponding to the top surfaces of the flanges of the members
10 and 11.
[0030] Alternatively, the assembly may be initially below the required level, and the placing
of the settable material may be such as to lift the assembly into the correct position
so that its top surface lies level with that of the settable material itself.
[0031] In order to prevent settable material dropping into the slot, this may be filled
with boards or other components which are afterwards removed.
[0032] If it is desired that the slot should be discontinuous, bridge pieces are inserted
at spaced positions along the length of the slot.
[0033] This assembly provides a continuous drain which may have a fall from one end to another.
Longitudinal and transverse levels are taken into account. Any expansion or contraction
of the settable material or its surrounding material as a result of changes in temperature,
or other movement, is readily accommodated by movement of the members 10 and 11 under
the influence of the spring spacers.
[0034] The spring or equivalent spacers may be used in other circumstances in bridge or
road engineering where expansion is to be accommodated.
1. An assembly for use in drain construction characterised by an elongate, generally
tubular conduit (12), having, extending along the length thereof, an elongate opening
which is narrower than the conduit and faces upwardly in use of the assembly, and
two spaced elongate wall members (10, 11) connected to the conduit along opposite
sides of the opening and extending away from the opening so as to define between them
a slot communicating, through the opening, with the interior of the conduit (12).
2. An assembly according to Claim 1, characterised in that adjustable spacing means
(21) are provided between said elongate wall members (10, 11).
3. An assembly according to Claim 2, characterised in that said adjustable spacing
means include spring means (21) interconnecting the wall members (10, 11) in a manner
tending to urge the wall members apart.
4. An assembly according to Claim 3, characterised in that said spring means comprise
a helical compression spring (21).
5. An assembly according to Claim 2, characterised in that said adjustable spacing
means comprise a temperature responsive device connected between the wall members
(10, 11) in a manner to adjust the spacing between the wall members in accordance
with the ambient temperature.
6. An assembly according to any of Claims 3 to 5, characterised in that said adjustable
spacing means are enclosed in a protective sleeve (16, 17) extending between the wall
members (10, 11).
7. An assembly according to Claim 6, characterised in that the protective sleeve comprises
two telescoping parts (16, 17) which may slide relatively to one another to accommodate
relative movement between said wall members (10, 11).
8. An assembly according to any of the preceding claims characterised in that the
generally tubular conduit (12) is formed of flexible material so that adjustment of
the spacing between the wall members (10,11) is accompanied by corresponding adjustment
of the width of the opening in the conduit, said adjustment being permitted by flexure
of the walls of the conduit.
9. An assembly according to any of the preceding claims, characterised in that there
are provided on each wall member (10,11) a plurality of alternative locations (15)
for attachment of the conduit thereto, whereby the depth of the slot provided between
the wall members, relative to the conduit, may be adjusted.
10. An assembly according to any of the preceding claims, characterised in that a
location for attachment of the conduit to each wall member (10, 11) is provided by
at least one longitudinally extending groove (15) along the outer surface of the wall
member, into which grooves are engageable the two edges of the conduit (12) which
define the aforesaid opening therein.
11. An assembly according to Claim 10, characterised in that the conduit (12) is formed
of resiliently flexible material arid said edges of the conduit are retained in said
grooves (15) by the resilience of the conduit.
12. An assembly according to any of Claims 1 to 11, characterised in that the conduit
(12) is formed from resiliently flexible plastics material.
13. An assembly according to any of Claims 1 to 12, characterised in that the conduit
(12) is generally circular in cross-section.
14. An assembly according to any of Claims 1 to 13, characterised in that the width
of the slot defined by said wall members (10, 11) increases as it extends towards
the conduit (12).
15. An assembly according to any of Claims 1 to 14, characterised in that the edge
of each wall member (10, 11) remote from the conduit is provided with an outwardly
extending flange.
16. An assembly according to Claim 15, characterised in that each outwardly extending
flange is formed, on the surface thereof facing away from the conduit (12) with spaced
grooves (13) extending transversely to, and opening into, the slot defined by the
wall members (10, 11).
17. An assembly according to Claim 16, characterised in that the bottom walls of said
grooves (13) are inclined towards the conduit (12) as they extend towards the slot
defined between the wall members (10,11).
18. A method of installing a drain construction for draining water from the surface
of the ground, characterised by the steps of forming a trench in the ground, locating
within the trench at least one assembly according to any of Claims 1 to 17, with the
slot defined by said wall members (10, 11) facing upwardly and the upper edges of
the wall members substantially level with the surface of the ground, and then filling
the trench up to ground level around the assembly with a material (24) which is such
as to embed and support the assembly.
19. A method according to Claim 18 characterised in that the material (24) in which
the assembly is embedded is concrete.
20. A drain construction when formed by the method of Claim 18 or Claim 19.