PROCEDURE FOR MANUFACTURING A SCREEN-MAT AS AN IN-LAY FOR SYSTEMATIC-SCREEN FIELDS, AND A SCREEN-IN-LAY FOR SYSTEMATIC-SCREEN FIELDS

17-11-1988 дата публикации
Номер:
AU0001612488A
Автор: NAME NOT GIVEN
Принадлежит: Steinhaus GmbH
Контакты:
Номер заявки: 1612488
Дата заявки: 13-05-1988

[1]

(54) Title PROCEDURE FOR MANUFACTURING A SCREEN-MAT AS AN IN-LAY FOR SYSTEMATIC-SCREEN FIELDS, AND A SCREEN-IN-LAY FOR SYSTEMATIC-SCREEN FIELDS International Patent Classification(s) (5\y B07B 001/46 B07B 001/00 (21) Application No.: 16124/88 (22) Application Date : 13.05.88 (30) Priority Data (31) Number (32; Date (33) Country 3716472 16.05.87 DE FEDERAL REPUBLIC OF GERMANY (43) Publication Date : 17.11.88 (44) Publication Date of Accepted Application : 21.02.91 (71) Applicant(s) STEINHAUS GMBH (72) Inventor(s) KURT WOLFF (74) Attorney or Agent SPRUSON & FERGUSON, GPO Box 3898, SYDNEY NSW 2001 (56) Prior Art Documents AU 559443 21009/83 B07B 1/46, 1/04 AU 512919 29598/77 B07B 1/46, F16S 3/08 (57) Claim 1. A method of manufacturing by extrusion square or rectangularscreen-mats of a rubber-elastic, thermoplastic, synthetic material with perforated zones, ^or screen in-lays of systematic-screeh fields, the Screen-mats having boshable, continuous, longitudinal protruding ribs on the underside of longitudinal edges thereof, and being attached integrally thereto, the method comprising a section corresponding in length to the screen-mat being cut from flatmaterial; and on the underside, in an area between the longitudinal edges of the material section, transverse strips are glued on or welded on, which strips have bosh ribs protruding from their lower tides.5. A serein in-lay for systematic-screen fields with square or rectangular frame elements Which can be attached to a substructure, on which a correspondingly square or rectangular screen-mat made of a thermoplastic synthetic material being cut from an endless flat material and having perforated areas is attached in such a way as to be removable which screeR-mat has bofhable, continuous ribs, which can be boshed into e0rresponding recessions at the upper sides of the flanges of the frame'.. /2!', ! -Ik1 Vw S\ 'j >J[.l' w; **+'•i; mi jfef; ,.

[2]

!', ! -Ik1 Vw S\ 'j >J[.l' w; **+'•i; mi jfef; ,.

[3]

(11)AU-B-16124/88-a-(tO)606948elements, wherein at least one longitudinal rib formed Integrally onto the longitudinal edges of said flat material runs through until Its end Is formed onto the underside of each of the two longitudinal edges of the screen-mat, and strips protruding downwards are attached at the underside of the two transverse sides of the screen-mat between the two longitudinal edges, which have bosh ribs protruding downwards which are perpendicular to the longitudinal ribs. i : rMMNHMMxi S & F Ref: 55902 FORM 10COMMONWEALTH OF AUSTRALIAPATENTS ACT 1952COMPLETE SPECIFICATION(ORIGINAL) FOR OFFICE USE: Class Int Class Complete Specification Lodged Accepted Publi shed • • •• Priority: .Related Art: ""Name and Address ►••••• of Applicant: Steinhaus GmbH Platanenalle 46 D - 4330 Mulheim FEDERAL REPUBLIC OF GERMANY » • ••« ••« Address for Service; Spruson & Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia > • • • •• • Complete Specification for the Invention entitled: »;•••: Procedure for Manufacturing a Screen-Mat as an In-Lay for Systematic-Screen Fieldstand a Screen-In-Lay for Systematic-Screen" Fields The following statement is a full description of this inyention, including the best method of performing it know*! to me/us 5845/3 i f ^i.Aiim"rThe present invention concerns a procedure for manufacturing a screen-in-lay for systematic-screen fields, and such a screen-in-lay, with square or rectangular frame elements which can be attached to a substructure, on which a correspondingly square or rectangular screen-mat made of a rubber-elastic material, with perforated areas Is attached In5 such a way as to be removable. The screen-mat has boshable, continuous ribs, which can be boshed into corresponding recessions at the upper sides of the flanges of the frame elements. The manufacturing expense for such a screen in-lay Is to be reduced by having a section of a flat material cut off for the manufacture of the screen-mat, such that only minimal work must10 still be undertaken on such a section in order to obtain a completed screen-mat. For this purpose, at least one longitudinal rib running through until the ends is formed onto the underside of each of the two longitudinal edges of the screen-mat, the strips protruding downwards are••• attached at the underside of the two transverse sides of the screen-mat •• • . '.3 5 between the two longitudinal edges, which have bosh ribs downwards which are perpendicular to the longitudinal ribs. » • • •• • • A screen in-lay is known from Publication DE-U1 82 35 2125 on which »• • • bosh ribs are installed at the lower side to the screen-mat, parallel along the outside edges; these are either placed upon the screen-mat or20 constructed as part of the latter. However, to place the bosh ribsclrcumferentlally around the lower edge of the screen^mat is a complicated and therefore expensive work procedure, while on the other hand, the construction of such a screen-mat with such bosh ribs incorporated into it which are Installed clrcumferentlally upon it, is made more expensive due25 to the fact that, in the usual casting manufacturing process, a separate,*open casting mold has to be provided, and the open-casting procedures in*centrifuges or casting plates are very expensive. Such screen-mats are j manufactured of duroplastlc synthetics such as polyurethane, either with orwithout sifting-holes. In manufacturing without sifting holes, a 30 subsequent manufacture of sifting-holes by means of punching occurs. The punched out pieces, the so-called hole-scraps, are not recyclable and are hence waste."URLF/25931'MmmilIt H the object of the present Invention to overcome or substantially ameliorate the above disadvantages.There Is disclosed herein a method of manufacturing by extrusion square or rectangular screen-mats of a rubber-elastic, thermoplastic, synthetic material with perforated zones, for screen In-lays of 5 systematic-screen fields, the screen-mats having boshable, continuous, longitudinal protruding ribs on the underside of longitudinal edges thereof, and being attached Integrally thereto, the method comprising a section corresponding In length to the screen-mat being cut from flat material; and on the underside, In an area between the longitudinal edges 10 of the material section, transverse strips are glued on or welded on, which strips have bosh ribs protruding from their lower sides.There Is further disclosed herein a screen in-lay for systematic-screen fields with square or rectangular frame elements which • •• • • •••can be attached to a substructure, on which a correspondingly square or •.55 rectangular screen-mat made of a thermoplastic synthetic material being cut ..I from an endless flat material and having perforated areas is attached in , such a way as to be removable, which screen-mat has boshable, continuous > • • •••ribs, which can be boshed into corresponding recessions at the upper sides Of the flanges of the frame elements, wherein at least one longitudinal rib 20 formed Integrally onto the longitudinal edges of said flat material runs through until Its end Is formed onto the underside of each of the two ViifS »• •♦• •••• •••• *longitudinal edges of the screen-mat, and strips protruding downwards are attached at the underside of the two transverse sides of the screen-mat*between the two longitudinal edges, which have bosh ribs protruding 25 downwards which are perpendicular to the Tpngltudlnal ribs.*The screen-mat may be manufactured of an, feasily-manufactured flat*material of rubber-elastic production material, whereby the flat material*is first of all extruded using a suitable 'syntheitlc, advantageously in such*a way that the longitudinal ribs of what is to become the screen-mat which 30 are to serve as bosh elemehts, are already formed integrally onto the twolongitudinal edges. Thermoplastic synthetic material is suitable for extrusion, and offers the additional advantage that, with the renewed application of heat and pressure, possibly after being reduced to small*3- pieces, the parts involved can be repeatedly reformed. Thus, superfluous or rejected parts made of thermoplastic synthetic material are not waste material; rather that material can be used to manufacture new parts. Although it is basically possible that the perforated areas of the inventive screen-mat may be formed in the material immediately during the extrusion procedure, or immediately thereafter, it is especially advantageous to punch the holes into the completed flat material, or into the cut-off section thereof which corresponds to the length of the screen-mats. For in that case, the punched-out portions, the so-called hole-scraps, may if necessary be passed back to the raw material from which the flat material is formed. That is only possible because a thermoplastic synthetic material is used for the screen-mat.It ic important ^RatT[/strike]bosh' means may be installedsubsequently at the transverse sides of the flat sections, which are cut off to the lengths of • ••• •• •• • • screen-mats, for the complete edge-circumferential attachment of the I screen-mat onto the frame-flang'es, by gluingon or weldingon stripswhich • for this purpose protrude downward, between the longitudinal edges, and at short intervals between the longitudinalribs of the flat-material section concerned, whichstripsagain have ribsprotruding downwards. Thus it is ' possibleto produce screen-mats of prescribedwidth,but of variable length, extremely economically,usingthe practicallyendlessly#»J • * reproduceable flat material,which may be stored in rolls of great length.

[4]

« •» It is of no importance whether or not the perforated areas reach to the edge of the screen-mat at the transverse sides,since a reinforcemeht of the transverse sides by '.eans of the separately-attached bosh strips will in any case result. On the other hand, it is possible to provide transverse-flanges in the flatmaterial between perforated areas which are separated from one another, along the longitudinalmiddle of which flanges the flat material is separated during the cutting-off of the flat-material • •••tpo&y we. •30 • sections. In this way, transverse-edges •^P^^obtained at the cut-off flat-material transverse-sections, at the bottom sides of which the bosh strips can then be glued or welded on. That, of course, presupposes that a certain grid-measurement be maintainedduring the cutting-off of the individualmaterial sections, whichmeasurement shallbe predetermined by the interval of the transverse flanges between the perforated zones of the flat material. -^[strips which, if appropriate, protrude downwards from the transverse edges of the completed screen-mat, and the bosh ribs lab located there,, require that depressions be provided in the basically Bfheah WW-4- •Am 4^ a^^^^o^^v .<^ihJ3u£tt6/&3&<&»S»iZ._£«&B&'3.&^l*Ja*1*~~u^fV.^ Ttg]r~r.r^-..*-..™»*.~-T-.—-^ parallel-planed top side of the frame flanges with the negative contour of the strips protruding downward from the underside of the screen-mat. Corresponding groove-shaped recessions are located at the bottom of these depressions for the reception of the bosh ribs which are installed on the strips attached to the underside of the screen-mat.

[5]

cofY-vpnse -[strike]The st[/strike]a[strike]ted[/strike] ad[strike]vantages [/strike][strike]are provid[/strike]e[strike]d also with[/strike]'screen in-lays/v«4fr screen-mats which have one or more medial flanges parallel to the edge flanges. These medial flanges, too, are part of the original flat material, whereby here, too, a form-locking connection using one or more of the bosh 10 ribs formed onto the underside of the medial flanges, with the corresponding medial flanges of the flat-material elements is possible.Since the inventivescreen in-layis also useful for equippingoscillatingscreens, the additional form-locking connection between the medialflanges of the screen-mat and of the frame element,, respectively, can be dispensed with. .-.j For use with especiallycriticalsifting-material with a tendency to infiltrate the screen-mat in the area of its bearingpoints, it is advantageous to provide at least two parallel bosh ribs and grooves each for the form-locking connection between the screen-mat and the frame flanges, which should be installed as close to the two mutually opposite ':« longitudinaledges of the frame flanges.. It is also possible to give the installed sereen-mat a drum-head-like • •• » ••» • •• tension by means of the TnstalTatign of the bosh ribs onto the screen-mat on the one hand and the correspondingly-selected intervals of the associated bosh grooves on the upper side of the frame elements on the other, particularly if the transverse intervals, of the longitudinal bosh strips, on the underside of the screen-mat are less than the transverse intervals of the corresponding bosh grooves on the upper side of the framed elements.

[6]

*- Additionaladvantageous embodiment characteristicsof the invention •' may be deduced from the subordinate claims. The invention will below be- explained in greater detail by reference to the drawing and by way of a single embodiment exatople. The drawing: shows in top-diagonal perspective view a screen-in-lay element for a systeitiatic-sGreen field. In particular, the drawing shows a frame element 1 which can be rigidly connected by means Of attachment meahs, which are not shown, with a substructure of a systematic-scmn field. In particular, bosh or expansion anchors can be used for this purpose, which anchors can be fdrmed onto the * ( frame eleftient 1 with an underside-overlap, provided that element is made of eah 1072P-5- a sufficiently-elastic working material. A large number of such frame elements 1, which have a square and/or rectangular basic shape, are required to cover a systematic-screen field, whereby the frame elements 1 are arranged in such a way as to interlock tightly with one another. They represent in each case only the intermediate element which carries the activesifting element, and can remain rigidly connected to the substructure if the sifting elements are to be replaced. Each frame element 1 is composed of longitudinal flanges 2 and transverse flanges 3, the upper sides of which form a support. In addition,medial flanges 4 may extend between the transverse flanges 3, parallel to the longitudinal flanges 2. Bosh grooves 5 are formed into the upper sides of the longitudinal flanges 2, which serve as a support, and possibly, too, into the medial flanges 4, which grooves are parallel to one another in the longitudinaldirection of the frame element 1. In each case, they extend up to the transverse-sideends of the frame element 1. On their supporting upper sides, the transverse f'anges 3 have bosh grooves 6 which are parallel to one another in the transverse direction, whereby in this case, the supporting upper sides are formed in each case by the bottom » • • ••• 16 of the depressions 15. Tie bosh grooves 6 may, for technical reasons •25 • relating to the shape, be drawn through to the longitudinalsides of the frame element 1, whereby intersticeswith the bosh grooves 5 of the • •• longitudinal flanges 2, and possibly also with those of the medial flanges• ••• • 4, wi 11 then be formed.

[7]

I A screen-mat 7 made of a thermoplasticsyntheticmaterial is snapped m»»monto the upper side of the frame element 1, which has perforated zones 8 in the area between the longitudinalflanges 2 of the frame element 1. At least along the underside of its edges 9, the screen-mat 7 is connected by '.••. form-lock by means of the bosh grooves 5 with the longitudinalflanges 2 of . the form element 1, which purpose is served by corresponding longitudinal •30 * ribs 11 at the underside in the edge area of the screen-mat 7. Beyond the area of contact of the longitudinalribs11, the screen-mat 7 , the screen-mat 7 has a level support surface, whereby the longitudinal ribs 11 which protrude above the underside of the screen-mat are formed integrally as part of the screen-mat. In the same manner, the screen-mat 7 may have one or more flanges 12 along its longitudinal median, with one or more longitudinal ribs 11 placed against its underside. Strips 13 of approximately the same width as the transverse flanges 3ais of the frame element 1 are attached to the underside of the screen-mat 1 V\between the median flange 12 and the longitudinal edges 9, which overlap liah 10721* the screen-mat 7 on the lower side. The strips 13 can be glued or welded onto the underside of the screen-mat 7, so that they protrude downwards past the supporting surface of the screen-mat 7. The above-mentioned depressions 15 at the upper side of the frame element 1 in the area of the transverse flanges 3 form the negative profile of the strips 13, so that when the screen-mat 7 is boshed onto the frame element 1, the strips 13 can protrude into these depressions 15 in such a way as to form-lock. Bosh ribs 14 running in the transverse direction serve to bosh the strips 13 together with the bosh grooves 6 in the area of the depressions 10 15 of the transverse flanges 3 of the frame element 1, which ribs are formed integrally onto the strips 13 and protrude downward beyond the underside of the latter. Due to the later attachment of the strips 13 onto the screen-mat 7, the bosh ribs 14 cannot run transversely across the entire width of the screen-mat 7 in the.

[8]

• •»• • • •• The strips 13 can even be attached sufficientlyfirmly to the *. I screen-mat 7 if — as shown in the drawing — the perforated zones 8 run * ...! through to the transverse side. The strip 13 covers perforated zone 8 ..., from the bottom in the transverse edge area in such a way that the sifted *** material cannot affect the transverse flanges 3 of the frame element 1, W* which are below it. The sqreen-mat 7 is. connected detachably to the frame element 1 at • •• i • • •• its uh-derside along the longitudinal edges 9 and the frame ribs 14, by means of the bosh ribs 1.1. It can therefore be replaced, like an • •• independent exchangeable part, without the frame element 1 having to be .. removed from the supporting structure of the systematic-screen field. Thus, the screen-mat 7 is an in and of itselfexchangeable,activesifting element. .^..^ During production, the screen-mat 7 is cut off from a prefabricated ". flat material, whereby the bosh flanges 11 are already formed into the flat •30 • material along the longitudinal edges of the latter. The perforated zones 8 can also be formed in during production of the flat material, or else punched in afterwards. After cutting of the flat material to the necessary length of each screen-mat 7, the strips 13 with the bosh ribs 14 running in transverse direction are glued or welded onto the underside of the sereen-mat 7. The strips, too, may be cut off of a prefabricated flat materlal.

[9]

n SBfheah 1072P -7- IThe claims defining the Invention are as follows:1.A method of manufacturing by extrusion square or rectangular screen-mats of a rubber-elastic, thermoplastic, synthetic material with perforated zones,, for screen In-lays of systematic-screen fields, the screen-mats having boshable, continuous, longitudinal protruding rtbs on the underside of longitudinal edges thereof, and being attached Integrally thereto, the method comprising a section corresponding in length to the screen-mat being cut from flat material; and on the underside, in an area between the longitudinal edges of the material section, transverse strips are glued on or welded on, which strips have bosh ribs protruding from their lower sides.2.The method of Claim 1, wherein the flat material is first of all produced without the perforated zones, and the perforated zones are thereafter punched into the flat material.3.The method of Claim 1, wherein the perforated zones are punched into the cut-off flat material sections.4.The method of Claim 1, wherein the perforated zones are formed into the synthetic material during extrusion.5.A screen in-lay for systematic-screen fieldswith square or rectangular frame elements which can be attached to a substructure, on which a correspondingly square or rectangular screen-mat made of a thermoplastic synthetic material being cut from an endlessflat material and having perforated areas Is attached in such a way as to be removable, which screen-mat has boshable, continuous ribs, which can be boshed into corresponding recessions at the upper sides of the flanges of the frame elements, wherein at least one longitudinalrib formed Integrally onto the longitudinal edges of saidfUt material runs through until its end is formed Onto the Underside of each of the two longitudinal edges of the Screen-mat, and strips protruding downwards are attached at the underside of the two transverse sides of the screen-mat between the two longitudinal edges, which have bosh ribs protruding downwards which are perpendicular to the longitudinal ribs,6.A screen In-lay according to Claim 5, wherein the strips on the transverse sides of the screen-mat overlap the underside of the latter, and that the transverse frame flanges provide depressions as negative contours • ••• » • imfmmr^M^t totfe^. JJ^-j^-jrfitrYtnpaafiM-iiau j^aA'^^Bfte^^J<aBk....,-ww.jarti't asw. Jin.ta^j^^v4i^ • • *•• ••*of the protruding strips, at the bottom of which the recessions for the reception of the bosh ribs are attached to the strips.?. A screen In-lay according to Claim 5 or 6, wherein the screen-mat has continuous perforated areas up to Its ends, and the strips are attached to the screen-mat by covering the end areas of the perforated areas.8.A screen In-lay according to any of Claims 5 to 7, wherein the strips are glued or welded together with the screen-mat.9.A screen In-lay according to any of Claims 5 to 8, wherein at least two mutually parallel longitudinal ribs are Installed at the underside of the longitudinal edges of the screen-mat, as well as two mutually parallel bosh ribs on the bosh strips, and at least two bosh grooves, corresponding to the upper sides of the frame flanges are Installed in such a way that the bosh connections are located close to the two edges of the frame flanges.10.A screen in-lay according to any of Claims 5 to 9, wherein the screen-mat and the frame element have medial flanges, whereby the longltudinany-running medial flange of the screen-mat is likewise formed by longitudinal flanges protruding downwards.11.A screen in-lay according to Claim 10, wherein the median longitudinal flanges of the screen-mat likewise have longitudinalribs at their undersides, and bosh grooves are correspondingly installed at the upper sides of the median flanges of the frame elements.12.A method of manufacturing square or rectangular screen-mats, the method being substantially as hereinbefore described with reference to the accompanying drawings.13.A screen in-lay substantially as hereinbefore described with reference to the accompanying drawings.DATED this THIRTIETH day of OCTOBER 1990 Steinhaus GmbHPatent Attorneys for the Applicant SPRUSON & FERGUSON-1j0^RLF/2593ffim —i iiifri--------^--^ 16 124/88 • • ••• •••• •• •••• • « • •••• ••• • •• ••• • ••* • •



[10]

The invention concerns a procedure for manufacturing a screen-in-lay for systematic-screen fields with square or rectangular frame elements which can be attached to a substructure, on which a correspondingly square or rectangular screen-mat made of a rubber-elastic material, with perforated areas is attached in such a way as to be removable. The screen-mat has boshable, continuous ribs, which can be boshed into corresponding recessions at the upper sides of the flanges of the frame elements. The manufacturing expense for such a screen in-lay is to be reduced by having a section of a flat material cut off for the manufacture of the screen mat, such that only minimal work must still be undertaken on such a section in order to obtain a completed screen mat. For this purpose, at least one longitudinal rib running through until the ends is formed onto the underside of each of the two longitudinal edges of the screen-mat, and strips protruding downwards are attached at the underside of the two transverse sides of the screen mat between the two longitudinal edges, which have bosh ribs downwards which are perpendicular to the longitudinal ribs.



Method of manufacturing square or rectangular screen mats of a rubber-elastic material with performated zones, for screen in-lays of systematic-screen fields, whereby the screen mats have boshable, continuous ribs on the undersides of their edges,

characterized in that

the rubber-elastic material is a thermoplastic synthetic material; that a flat material is made therefrom, at the two longitudinal edges of which the ribs are attached integrally so as to protude from the underside; that a section corresponding in length to the screen mat is cut off from the flat material; and that on the underside, in the area between the longitudinal edges of the material section, strips are glued on or welded on, which strips have bosh ribs protruding from their lower sides.

Method according to claim 1,

characterized in that

the stips to be attached in the area between the longitudinal edges of the material section are glued or welded directly onto the underside of the material section, overlapping the latter from the bottom.

Method according to claim 1,

characterized in that

the flat material is first of all produced without the perforated areas, and that the perforated areas are thereafter punched into the flat material.

Method according to claim 1,

characterized in that

the perforated areas are punched into the cut-off flat material sections.

Method according to claim 1,

characterized in that

the flat material is extruded of synthetic material, and that the perforated areas are formed into the synthetic material during extrusion.

A screen in-lay for systematic-screen fields with square or rectangular frame elements which can be attached to a substructure, on which a correspondingly square or rectangular screen-mat made of a rubber-elastic material, with perforated areas is attached in such a way as to be removable

characterized in that

the screen-mat (7) comprises boshable, continuous ribs (9,10), which can be boshed into corresponding recessions at the upper sides of the flanges of the frame elements (1), that at least one longitudinal rib (11) running through until the ends are formed onto the underside of each of the two longitudinal edges (9) of the screen-mat (7) and that strips (13) protruding downwards are attached at the underside of the two transverse sides of the screen mat (7) between the two longitudinal edges, which have bosh ribs (14) protruding downwards which are perpendicular to the longitudinal ribs (11).

A screen in-lay according to claim 6,

characterized in that

the strips (13) on the transverse sides of the screen-mat (7) overlap the underside of the latter, and that the transverse frame flanges (3) provide depressions (15) as negativ contours of the protruding strips (13), at the bottoms (16) of which the recessions (6) for the reception of the bosh ribs (14) are attached to the strips (13).

A screen in-lay according to claim 6 or 7,

characterized in that

the screen-mat (7) has continuous perforated areas (8) up to its ends, and that the strips (13) are attached to the screen-mat (7) by covering the end areas of the perforated areas (8).

A screen in-lay according to claims 6 to 8,

characterized in that,

the strips (13) are glued or welded together with the screen-mat (7).

A screen in-lay according to claims 6 to 9,

characterized in that,

at least two mutually parallel longitudinal ribs (11) are installed at the underside of the longitudinal edges (10) of the screen-mat (7), as well as two mutually parallel bosh ribs (14) on the bosh strips (13), and that at least two bosh grooves (5,6) corresponding to the upper sides of the frame flanges (2,3) are installed in such a way that the bosh connections are located close to the two edges of the frame flanges (2,3).

A screen in-lay according to claims 6 to 10,

characterized in that

the screen-mat (7) and the frame element (1) have medial flanges (4,12), whereby the longitudinally-running medial flange (12) of the screen-mat (7) is likewise formed by longitudinal flanges protuding downwards.

A screen in-lay according to claim 11,

characterized in that

the median longitudinal flanges (12) of the screen mat (7) likewise have longitudinal ribs (11) at their undersides, and that bosh groves are correspondingly installed at the upper sides of the median flanges (4) of the frame elements (1).

A screen in-lay according to claims 6 to 12,

characterized in that

the screen mat (7) consists of a thermoplastic synthetic material.