CA1073227A - Pipe for underdraining - Google Patents

Abstract

TITLE OF THE INVENTION
Pipe for Underdraining ABSTRACT OF THE DISCLOSURE
A pipe for underdrainage comprises (1) a liquid collecting pipe; (2) a plurality of discontinuous protrusions on the outer surface of the liquid -collecting pipe; (3) a filter layer capable of passing substantially liquid only, not solid, the filter layer being disposed around the liquid-collecting pipe and contacting the top portions of the pro-trusions; and (4) a liquid-conducting way composed of a space communicating both in the longitudinal direction and in the peripheral direction as the liquid collecting pipe and defined by the protrusions, the outer surface of the liquid-collecting pipe and the inner surface of the filter layer.

Description

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,AClCGROUND OF THE INVF.NTION
-1. Field of the Invention Thls invention relates to a pipe for underdr~ining.

2. Description of the Prior ~rt Since prior art pipes for underdraining have -through holes on the pipe wall and nothing else, various filter materials such as rubbles, gravels, chaffs and the like are disposed around the pipe for the purpose of preventing choking of the through holes and enhancing the water-collecting capaci-ty. Howe~er, it is very difficult to prevent completely clogging and further the working is complicated and requires many hands.

SUMMARY OF THE INVENTION
_ An object of the present invention is to provide a pipe for underdraining free from the above mentioned drawbacks !
Another object of the present invention is to provide a pipe for underdrainage having a filter member substantially free from clogging.
A further object of the present invention is to provide a pipe for underdrainage which can be easily arranged.
Still another object of the present invention is to provide a pipe for underdrainage which enables to construct an underdrain-age system without requiring many hands.
According to the present invention, there is provided a pipe for underdrainage which comprises:
(1) a liquid-collecting pipe;
(2) a plurality of discontinuous protrusions on the outer surface of the liquid-collecting pipe;

(3) a plurality of through-holes on the outer surface of the liquid collecting pipe and between the discontinuous protrusions;

(4) A filter layer which permits the passage of liquid wnile substantially excluding solids, the filter layer being , ,~

2 ~ :
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, lisposed around the liquid collecting pipe and contac-ting the top portions of the protrusions; and

(5) a liquid-conduc-ting way composed of a space communicating both in the longitudinal direction and in the peripheral direction of the liquid collecting pipe and defined by the protrusions, the outer surface of the liquid-collecting pipe and the inner surface of the filter layer.

BRIEF DESCRIPTION OF THE DF~AWING
FIG. 1 is an oblique view of an embodiment of the present invention;
FIG. 2 is a cross-sectional view of the embodiment in FIG. l;
FIG. 3 is a cross-sectional view of another embodiment of : the present invention;
FIG. 4 is an oblique view of a further embodiment of the present invention;
FIG. 5 is an oblique view of a still another embodiment of the present invention;
FIG. 6 is an oblique view of a still further embodiment of the present invention;
FIG. 7 is an oblique view of a still another embodiment of : the present invention; .
FIG. 8 and FIG. 9 are oblique views of still further embodiments of the present invention;
FIGS. 10A, 10B, 10C and lOD show connecting portions of ' ~ pipes for underdraining of the present invention, FIGS. 10A and .
lOB are side views of joint members, and FIGS. 10C and lOD are - -cross sectional views thereof;

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~' : ' FIG. 11 is a side view, partially in section, of liquid collecting pipes connected with each other; and FIG. 12 is an oblique view of a further embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following the present invention is explained referring to the attached drawing.
A pipe for underdrainage 1 is composed of a liquid-collecting pipe 2, discontinuous protrusion portions 3, 3 ----and a filter layer 4 as shown in FIG. 1 and FIG. 2 (the filter layer is not shown in FIG. 1). A liquid-conducting way 5 is defined by the outer surface of liquid-collecting pipe and the filter layer 4.
In FIG. 1, protrusions 3, 3---- are regularly disposed zigzag and partly overlap in the peripheral direction.
However, the protrusions may be disposed irregularly since the protrusions are used for forming a certain space between filter layer 4 and the outer surface of liquid-collecting pipe 2.
The shape of protrusion 3 in FIG. 1 and FIG. 2 is a semicircular hollow rod or a rod having any other optional cross section. The protrusions 3 may be integrally formed with liquid-collecting pipe 2 or may be removably formed on liquid-collecting pipe 2.
In FIG. 1 and FIG. 2, the cross sectional shape of liquid-collecting pipe 2 is circular, but may be elliptical, triangular, or rectangular. And the protrusions 3 may be distributed all over the surface of the liquid-collecting ~1~ 13~Z~Y

l 1I p:ipe or di~pose~1 only at some partieular areas of sa.i.cl surrnce~
2 Suc1l deYi~ factors m~y ~e op-t.iona-LIy selecte(1 depen(1i.
3 !1 upon the ~urpose or constructil1~ t11e underdrc1ina~e .~ystc~
~ The refe~re11ce nulllera~ 6 deno-tes A li.qu:id way w1~ere a 1.:i.(lllid 5 ¦1 ~uch ~s w.~ter colleeted in the liquid-collectinS pipe l`:lows,

6 ¦ in FIGS. l - l1.
:[t is poss:ible to s11~1pe the protrusions 3 ~s il.:l llYt-8 ratod in FIG. 3 in sueh a way ~1at the wall thiekness :is uniform. l~hen the protrusions are so shaped, a hig11 stren~t of the pipe i.s ob-tainedlwit:h a small amount of plastics.
ll The s11ape of tlle protru.sions may be any form as far as a 12 space ean ~e formed between the outer surface of liquicl-13 colleeting pipe 2 and filter layer 1~, and may be optional.1.y ~lL seleeted for produeing desirclble resultsO
Il1 FIG. 1~, button-like protrusions 3, 3 ~ are 16 ¦ re~ularly d1.sposed zigzag on tl1e outer surfaee of liquid-17 ! eolleçting pi.pe 2, but mcly be irre~ularly d1sposed an~ the 18 ~ shape of protrusions 1!1ay be ~rustoeonieal.
l9 In FIG. 5, reetan~ular protr~sions 3, 3 ---- are ZO -disposed ~igzag, and the spaee volume ~etween the outer surfaee 21 of the liquid-eolleeting pipe 2 ~nd a filter layer 4 (not sho~n) 22 is not redueed by soil pre~sure beeause the size of the 23 ~ protruded portion is very large.
24 When the protrusions are in a form of strip, they inay be disposecl on the surfaee of liquid-colleeting pipe 2 26 longitudinally ~FIG. l and FIG~ 5), spirally and obliquely 27 (FIG. ~) or peripherally tFIG~-7)o This dispos.i.tion m~y be 2B seleeted optionally dependin~ upon the purpose of eonstrl1ction 29 and the tensile and the eompression strengt11s.
Colleetion of liquid into a li~u:id-colleeting pipe 2 ~ . 1 1 .
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1I can l~e accelerelted by provi.dills snla.ll throusll-holes a1; the 2 I pipe well.l of a li.qui.d-col].ecting pipe 2 whicll can conll~ icute 3 11' e~ uid-con(luctins way ~ith el liqll:i(l way 6.
4 ¦I FIG. o and liIG. 9 XIIOW Slll~ll throush-holes 7, 7 ----~ provided on the pipe wa:l.l of a liqu:Ld-collecting pi.pe 2.
6 The we~ter passing throllgh the fil-ter layer (not sho~ ) f:Lows .7 in the li~luid-conductins way and flows into the li~lu:id-co:l:l.ectin~
pipe 2 through the small through-lloles 7, 7----, and the snltl:Ll through-holes l-re provi.ded among protrusions. However, small through-hols3s may be provided at the protrusions. Furt:her, 11 small through-?loles may be provided on the liquid-collect.ing 12 pipes in the other embodiments in the drawing.
13 Conventional underdrelinage pipes having such smelll .
1:hrough-llole5 on the pipe we~ll suffer frolll clogging oi: the . .
1;hrough-holes while the u.nder(lrainase pipes accordins to t]le 16 present i.nvention are free from such drawback as clog~;ing celused by sand and~soil because a li(luid-conductin$ way 5 18 formed by a filter layer and protrusions is present.
19 Instcad of the sme~ll throu~;h-holes 7, ~ater can b~ ].ed into the liquid-collecting pipe 2 at the joint portion, 21 and if desired, small through-holcs may be provided tosether.
22 According to the present invention, the under~
23 drainage pipes may be ].ong or sllort, and when they are sl~ort, 24 if desired, they may be connected one another as shown in FIG. 10 a~d FIG. 11. :
26 FIG. lOA shows butt joint of underdrainase pipes ~1 27 by using a jo:int lS). IJI this case, liqu.id-condl.lcting ways 5 28 of both pipes ars~ directly connected and therefore, snla~
29 through-ho:Les 7 (e.g. in FIG. 8) are necesselry to i.ntrodllce ~30 , welter :in-to a liqui.d wa~r 6 :in l:he l:iqui.d-col.l.. ect:i.ns pipc 2.

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3;~ty ~ IG. 10C is a Ct'OS.S s~ct:i.on of th~ ~joint portioll of ~1(i. 10~.
2 1 ~ICI. l0M ~hows an elnl~o(l:iln-llt of introdllcil1s wa-ter :i.nto -t;he 3 ~ uid-co.l.l~cti.l1$ pipe 5 through the end portions of u~l-lel-~ drai.nase pipes. A concel1tric pipe type join-t 10 h.ls di.s-jl continuo~ls protrusions ll insille~ and in thi~ case, water G I celn be led intc, a liqu:id way 6 from a liquid-conduct:illg w~y 5,

7 1! but it is prcferal)ly to proYide the small through hol~s o 1I together.
9 11 ~IG. 10D is a cross section of the joint port.i.oll of ¦~ FIG. l0B.
ll I When the joint l0 h.ls a concentrlc contil1uous pro-12 ~¦ trusion inside (not shown), s~lall through-holes are necess~ry 13 I to comlllunicate the liqllid-conductins way with the liquid way, l~ ¦ ~ut even in such case, the small throu~h-holes are di.spen~able ¦ if tlle cross sectional shape in the .1.ongitudinal direction ¦ 16 I has a curved li.ne 12 in FIG. l0B (assuming that the protru.s:i~n 17 ¦ ll is continuous though the protrusions ll in FIG. 10B are I . ¦ discontinuous ones) and thereb~ the communication between 19 l¦ the li~uid-conducting way and the liquid way is not disturbed ¦ by the joint. ~ -21 I IDstead of the joint members 109 l0 in ~IG. l0, Z2 there ma~ bc used a pipe type joint having both reduced ends 23 or both enlarged ends for comlection.
24 It is also possi~le to connect the underdrainase pipes without e~lpIoying any particular joint member. I~or , .
6 example, in FIG.. ll, a liquid-collectins p:i.pe 2 has an .:
27 enl~r~ed end portion 7t an~ the left end of an ~Inderdrai.nase 28 pipe at the right hand is fitted into the enlarged end . Z9 portion 7 and there~y a liquid-conductins way 5 is con~ un.icl1ted `l 3 ¦ w:ith a liqllid way in the liq~lid-collectll1s pipe 2 at the left ,`, : i - ' ' ,, _ 7 --: , .
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1 l` halnl Thus, a l.iq~lid such as watcr pa.ss~s throush a f:il.tcr 2 k~ycr l~ an~ f].ow.s :in a li~1u~ colldllctin~ 5 (lerined l~y l:l1c 3 I filter layl~r ~l, tho outer surface of the li~luid col.l~cti 4 1 pipe and pJotrusions 3 a~ thell flows in-to a li.quicl way 6 at the enlarsed portion 7.
6 ¦ A furt~ler example of connectin~ the underdrainase 7 ¦ pipes of tllc presellt invel1tion is tllat one un~er~rairla~e pi.po

8 ! havins no filter layer at the end por-tion is fitted i.nto a

9 cylindrical filter layer extended from one end of the othcr ¦ underdrainase pipe.
1l As mentioned above, the li.quid-conduct:ins way is 12 communicated with tlle liqu:id way inside of the ]i~ui~-collectin~

13 pipe at the end portion and/or througll small throush-holes 1~ at the pipe wall of the l:iquid-collecting pipe, and the liquid-collecting efficiellcy is el~hanced.
16 ~IG. 12 shows allother embodimellt of the present 17 inventioll whicl-}las protruslons 2 d:isposed in a peripheral ;:

~8 direction and having recesses 4, and the recesses 4 are not '.:

1~ uniformly distributed Alons the peri.phery, but are present ~t 20 ~ two particular portions. Thi.s type of recess distribution is s 21 convenient for manufacturing the pipe by plastic moldin~, `22 i.e. for removing separated molds after moldins. In other 23 wor~s, a liquid-collectin~ p:ipe is firstly shaped and then 24 put between metal molds havins recesses and protrusions on the inside surface while the shaped pipe .is still hot and thereby ~26 a recess an(l protrusion pattern is formed on the surface of ; 27~ the pipe. In the above procedure, a two-sepa:rable metal mold 28 is usua].ly used and it is preferable to posltion thc rccesses at two portions to W}liCh directions from the axis of tl~e 3 pipe the two Inetal molds are separated for easy removal.
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1 ll In a s:illlil.lr way, :if a -tllree-separnble or more separal~le 2 ,ll mold iS used~ tllc recesses .,ro pro~ cecl.~t tl~c port.iol-ls or 3 tl~e pcriphcry to whicll (lir~c tiOJIS from tllo axis of tl 4 l' the sep.ll~.lt~ IllOl~lS are removed.
The fi.lter layer l~ WhiCIl captures solid partic].os 6 such as soil and sands flowins togetller w.ith und-3rgroull(l W.l ~er 7 and s~rface w~ter nnd al:Lows substantially liquid onLy to 8 pass through, ~sed in the present invention may be a syntllctic 9 resin nct, a net made of synthetic or natural fibers, a wovcn cloth, non-woven cloth,,a sheet-like material havin~ t}~ou~h-11 ¦ holes prochlced by a mec}lan:ical means, a foamed she~t, or a 12 foamed sheet having smnl:L throu~h-holes produced by rupturing 13 l foams during the foam shaping, or combination thereof, di.allleter 1l~ of the small hole is usually 0.1 - 5 mm., preferred with 1 ~ 2 mlll~ when produced by rupturing foams of a foa~ned sheet.
16 The filter layer 4 lllay be dispose~ around the 17 1 liquid-collecting pipe having protrusions by simply coveri.n~
lo the liquid-collecting pipe or fixed to the top portions of 19 the protrusions. Where both the protrusions and the filter : 20 layer are composed of s~nthetic resills, they can be .thermally .
21 adhered with each other so that the production7 construction . 22 and maintenance are easy and sure.
3 As mentioned above, the liquid-collecting way 5 24 of the underdrainage pipe according to the present invention communicates longitudinally as well as peripherally on tlle ~26 outer surface of the liquid-collecti.ng pipe 2 so that the ; a7 liquid can freely flow to various di.rections and the flow 28 . state is very good. The protrusions 3 function as ribs for 29 the liquid-co.l.lecting pipe so that mechanical stren~th of ~3 the li~uid-collectin~ pipe 2 is enh~nced. Wllere the ,,, ~ I _ 9 _ ~ :
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Z'7 ~ uid-col.lect~ p:ipe 2 alld tllo fil-ter layer It ar~ made of 2 syntllet:i.c res:i.JIS~ ~hey are li.gll-k, d~ra~le alld eorrosiorl-3 1I resistallt. In particular, where t:hey are n~acle of poLyo.l.efin, 4 l~ clo~ging harclly occurs.
¦I Tlle un(lerdlainage pipes according to t]le preserlt 6 1 invelltion can ~e easily used to ec~nstruet a sure under-7 ¦ drai.nage system witllout using con~entional filter materiuls c3 1 such as cllaffs, rubbles, and gravels~ but if desired~ suel~
9 ¦ eonventional filter material.s may be used together w:i.th tl~o 1 underdrainage pipes of ~he present invention.
l1 The underdra:inage pipe of the present inventi.on lllAy ~ -12 l be buried in the ground for facili.tatillg dra:inage at agricultura:l 13 l fields, ].ands for housing, damp grounds, playing fielcls, ll~ ancl telmis eourts. Play:ing fields and tennis eourts ean ~e used in a short time after rain.

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Claims (7)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A pipe for underdrainage which comprises:
(1) a liquid-collecting pipe;
(2) a plurality of discontinuous protrusions on the outer surface of the liquid collecting pipe;
(3) a plurality of through-holes on the outer surface of the liquid collecting pipe and between the discontinuous protrusions;
(4) a filter layer which permits the passage of liquid while substantially excluding solids, the filter layer being disposed around the liquid collecting pipe and contacting the top portions of the protrusions; and (5) a liquid conducting way composed of a space communi-cating both in the longitudinal direction and in the peripheral direction of the liquid collecting pipe and defined by the protru-sions, the outer surface of the liquid collecting pipe and the inner surface of the filter layer.

2. A pipe for underdrainage according to Claim 1 in which the protrusions are button-like.

3. A pipe for underdrainage according to Claim 1 in which the protrusions discontinuously extend in the longitudinal direction as to the liquid-collecting pipe.

4. A pipe for underdrainage according to Claim 1 in which the protrusions discontinuously extend in the peripheral direction as to the liquid-collecting pipe.

5. A pipe for underdrainage according to Claim 1 in which the protrusions discontinuously extend spirally.

6. A pipe for underdrainage according to Claim 1 in which the protrusions are hollow.

7. A pipe for underdrainage according to Claim 1 in which the protrusions are hollow and discontinuously extend in the peripheral direction as to the liquid collecting pipe and the filter layer is composed of a foamed sheet having small through-holes.