WO2001086086A1

WO2001086086A1 - Modular tile for building structures

Info

Publication number: WO2001086086A1
Application number: PCT/EP2001/005167
Authority: WO
Inventors: Adriano Morigi
Original assignee: U.S. Commercial Service
Priority date: 2000-05-05
Filing date: 2001-05-07
Publication date: 2001-11-15
Also published as: AU6391401A; EP1278923A1; ITTO20000423A0; IT1320332B1; ITTO20000423A1

Abstract

Modular tile (1) for building structures presenting a longer symmetrical axis A1 and a shorter symmetrical axis A2 which are at right angles to each other and which define four identical modular L-shaped sections (M4) on the tile (1) itself and presenting a respective rectangular lateral section: the tile (1) presents two side hollows (4) which are suitable for housing at least one lateral section (3) of another tile (1) in the same building structure.

Description

MODULAR TILE FOR BUILDING STRUCTURES

DESCRIPTION The present invention relates to a modular tile for building structures. A well-known technique in the building industry, for the construction of structures such as, for example, floors, slabs or the internal and external walls of buildings, is the use of tiles of a quadrangular shape, made of ordinary clay and fired in a kiln. Tiles of this type may be solid or hollow, which is to say that the latter type presents a determined number of internal channels suitable for reducing the overall weight, and these tiles are aligned in respective rows in which the tiles in each tow are staggered in relations to the tiles in the two adjacent rows, and a layer of mortar or cement is usually interposed between two adjacent rows of tiles in order to consolidate the building structure.

In the specific case of building a wall, once the necessary precautions have been taken regarding the vertical and linear nature of the wall itself, the positioning of the tiles of the type described above would be carried out fairly simply and rapidly if it were not for the fact that, in order to match the external sides of the wall with relative pillars or other architectural elements, such as doors and windows, some of the tiles have to be broken into at least two parts . It is obvious that the work involved in this adjustment to the length of the tiles is both time consuming in terms of man-hours and haphazard in terms of material .

The use of tiles of the type described above causes further problems in terms of man-hours because of the time necessary for the mortar or cement to harden; this is due to the fact that, before any kind of cables for electrical or telephone services - or any kind of pipes - can be installed, time must be spent waiting for the mortar or cement to become hard. Further problems are linked to the fact that other tiles must be broken in order to obtain the relevant housing channels in the newly-constructed walls, as well as which the newly-hardened mortar or cement must be broken - an operation which requires considerable time and effort. Finally, no matter how precise the checking of the vertical and linear nature of the wall might have been, walls which have been built using the kind of tiles described above generally display some irregularities, which means that it is usually necessary to carry out further finishing operations - a fact which clearly results in additional overall costs .

The aim of the present invention is to realise a modular tile for building structures which will avoid the inconveniences described above and which will, at the same time, permit a rapid and precise construction of the building structure itself.

According to the present invention, a modular tile for building structures will be realised, characterised by the fact that it comprises a first L-shaped modular section, which is provided with a longer and a shorter sides forming a right angle in relation to each other, and of which the longer side has a greater length than the shorter side. The invention will now be described in relation to the attached drawings, which illustrate a non- limiting embodiment of the invention, in which: FIGURE 1 shows a plan form of a first preferred embodiment of a modular tile for building structures according to the present invention; FIGURE 2 is a prospective view of the modular tile shown in FIGURE 1; FIGURE 3 illustrates, in section, a second preferred form of embodiment of the modular tile shown in FIGURE 1; FIGURE 4 illustrates, in section, a third preferred form of embodiment of the modular tile shown in

FIGURE 1;

FIGURE 5 illustrates, in section, a fourth preferred

form of embodiment of the modular tile shown in

FIGURE 1; FIGURES 6 and 7 are prospective views of a first modular part of the modular tile shown in

FIGURE 1; FIGURES 8 and 9 are prospective views of a second modular part of the modular tile shown in

FIGURE 1; FIGURES 10 and 11 are prospective views of a third

modular art of the modular tile shown in FIGURE 1;

FIGURE 12 shows a plan form of a further preferred form of embodiment of the modular tile shown in

FIGURE 1;

FIGURES 13 and 14 show a plan form of further preferred forms of embodiment of the modular tile shown in FIGURE 12 and in FIGURE 1; and FIGURE 15 illustrates, in section, another preferred form of embodiment of the modular tile shown in

FIGURE 1. With reference to FIGURE 1, the number 1 indicates, in its entirety, a modular tile for building structures such as, for example, floors, slabs, and internal external walls of buildings, but for reasons of clarity, the description which follows will make specific reference to the construction of walls, unless otherwise stated.

In a plan view, the modular tile 1 is double-T- shaped, and it presents two symmetrical axes, Al and A2, which are transverse in relation to each other, two longer sides L_max which are parallel to each other and to the axis Al, and two shorter sides L_min which are parallel to each other and to the axis A2. The sides L_max and _min present respective lengths l_max and l_min which are at least one order of size greater than a thickness S of the modular tile 1 itself, and the length l_max is equal to three times half the length of the length l_min. Furthermore, the thickness S may be less than the thickness of well-known modular tiles currently in use and so have the advantage, the external dimensions being equal, of having a greater usable surface.

The modular tile 1 comprises a central section 2 which has got a rectangular plan and extends along the axis Al, and four lateral sections 3, which have got a rectangular plan and are arranged two by two at opposite ends of the central section 2 and which are limited by the relative sides L_min and which extend opposite the central section 2 itself parallel to the axis A2. The two lateral sections 3 which are arranged along the same side L_max of the modular tile 1 present a first respective external side L3 which is parallel to the axis Al and is equal to a quarter of the length l_max of the side L_max itself and a second respective external side L3 which is parallel to the axis Al, it is equal to the first relevant side L3 , and it is axially staggered with respect relevant side L3. The two first side L3 define a hollow 4 between them, which determines an irregularity along the relative side L_max, and presents a length measured along the axis Al which is equal to half the length l_max and a depth measured along the axis A2 which is equal to a third of the length of the side L3.

A partial explanation of a description, which will be better^' explained later on, involves the positioning of the modular tile 1 for the construction of wall by placing the tiles 1 themselves on top of each other in parallel rows. The modular tiles 1 in each row are horizontally staggered in relation to the modular tiles 1 in the two rows adjacent to them, and they are arranged in such a way that the axes Al and A2 are respectively orientated horizontally and vertically, and in such a way that the hollows 4 of each modular tile 1 are engaged by two lateral sections 3 of the two adjacent modular tiles 1.

According to the illustration shown in FIGURE 2, the modular tile 1 comprises two flat walls 5, which are arranged on respective parallel planes and a lying plane P which is formed by the two symmetrical axes Al and A2 in a position facing each other. Each wall 5 presents a double T shape on the lying plane P itself, like on the modular tile 1, and has a thickness S_p which is less than the thickness S of the modular tile 1.

The modular tile 1 also comprises a number of connecting baffles between the two walls 5 which are arranged between the walls 5 themselves and are parallel to the axis A2. In particular, the modular tile 1 comprises two lateral baffles 6 which are arranged along the side L_min, and three pairs of internal baffles 7, and the baffles 7 of each pair define three channels 8, which present a substantially square shape on a right-angled plane to the lying plane P, while the baffles 7 of each pair define, with the baffles 7 of the other pairs and the other baffles 6, four channels 9 which present a substantially rectangular shape on a right-angled plane to the lying plane P. The lateral baffles 6 are arranged in a substantially indented position in relation to the external outline of the modular tile 1, and they define two projecting edges 10 on the walls 5 in correspondence to both the sides L_m:Ln, the two projecting edges 10 are parallel to the axis A2 and they are suitable for spacing the modular tile 1 from the two modular tiles 1 which are arranged adjacent to it in the same row in order to define, with the projecting edges 10 of the last modular tile 1, another channel 11 which, like the channels 8 and 9, is suitable for permitting the passage of cables and/or material for reinforcing the wall and/or pipes for the plumbing and heating system.

The modular tile 1 also comprises four further internal connecting baffles 12 between the two walls 5, which are arranged inside and along the four rectangular-shaped channels 9. As shown in FIGURE 3, it is possible to make an alternative modular tile 1' without the baffles 12, in order to make the modular tile 1 lighter. Each of the baffles 6, 7 and 12 presents at least three passing holes 13, which define, with the passing holes 13 of the other baffles 6, 7 and 12, respective passing conduits parallel to the axis Al which are suitable for permitting the passage of cables and/or pipes for the plumbing and heating system or for making the modular tile 1 lighter.

The modular tile 1 which is illustrated in FIGURE 2 present five conduits 14, whereas the modular tile 1" illustrated in FIGURE 5 presents only three conduits 14', two of which are obtained by combining two conduits 14 and 14' . In both cases, the most lateral conduits 14 and 14' create two further projecting edges 16 on the walls 5, the projecting edges 16 are parallel to the axis Al and are suitable for spacing the modular tile 1 from the two modular tiles 1 arranged in the two adjacent rows in order to define, with the projecting edges 16 of these last modular tiles 1, further channels 17 which have the same function as the channels 11.

According to the illustration shown in FIGURE 2, each wall 5 comprises sixteen extra channels 15 for purposes of lightening, which are arranged parallel to the axis A2 and through the wall 5 itself, and they are subdivided into groups which have four channels 15 each and which are located by the four rectangular-shaped channels 9.

According to the illustration shown in FIGURE 4, it is possible to make an alternative modular tile 1" in which each of the above-mentioned groups of channels 15 can, as an alternative, present a reduced number of channels 15', or even just two channels 15', and, according to the illustration shown in FIGURE 5, it is possible to make an alternative modular tile 1'" in which each the two flat walls 5 can be also provided with extra channels 15" which are parallel to the axis Al and have got the same purposes of the channels 15 and 15'.

The illustration shown in FIGURE 15 shows a modular tile 1^IV which is a further alternative embodiment of the modular tile 1 and differs from the modular tile 1 because one of the two walls 5 has got a double thickness with respect to the other wall 5 and it is provided with a double number of channels 15 which are arranged in two parallel rows.

According to a form of embodiment which is not illustrated, but which is easily understandable from the description given above, all the channels of the modular tile 1 can be completely filled, either with the same material used in the construction of the modular tile 1, or with different material in order to construct walls which are insulated or soundproof and in order to give to these walls a good resistance and sturdiness. Furthermore, the channels 15 and 15' can be filled by polystyrene foams of other sound absorbent materials to improve soundproofing of the building structures.

According to another form of embodiment which is not illustrated, but which is easily understandable from the description given above, when the modular tile 1 is used for building structures such as roofs, the wall 5 which is arranged above is not provided with the relevant projecting edges 10: in this way two modular tiles 1 arranged close to each other and in contact along their relevant side L_min form a open channel 14 which is suitable to be filled and allows the filling of all the channels 15 improving the anti-seismic characteristics of the roofs.

In its basic form, as well in all its variations, the modular tile 1 which has just been described above should be considered to be a modular unit Ml, that is to say a unit which permits the construction of building structures when assembled with other units of the same kind, but it should also be considered to be a modular unit in itself, that is to say a unit which can give rise to further sub- modules or modular sections. In particular, the two symmetrical axes Al and A2 create four modular portions M4 on the modular tile 1 which are L-shaped and identical to each other. Each modular section M4 involves a relative lateral section 3 and a quarter of the central section 2, and is laterally delimited towards the outside by half of a side L_min, by a side L3 , and by half of a hollow 4, while it is laterally delimited towards the inside by a respective longer side LI which extends along the axis Al and presents a length which is equal to half of the length L_max, and is also delimited by a shorter side L2 which extends along the axis A2 , and which presents a length equal to two thirds of the length of the side LI.

As is illustrated in FIGURES 6 and 7, each modular section M4 creates a fraction 100 of modular tile which is conceptually identical to the modular tile 1 as regards all the characteristics which have been described so far, and which is suitable for being assembled together with the modular tile 1 for the construction of building structures. For example, a fraction 100 may be used at the end sides of an initial row at the bottom of a wall, or of a last upper row of the wall itself, and the relative lateral section 3 may be inserted inside one half of a hollow 4 of a modular tile 1 in a row adjacent to the first or last one.

Two different modular sections M2 and M2 ' , which are respectively T and C shaped, may be obtained by uniting two modular sections M4 along the respective sides LI or the respective sides L2.

As is illustrated in FIGURES 8 and 9, each modular section M2 creates a fraction 200 of modular tile which is conceptually identical to the modular tile 1 as regards all the characteristics which have been described so far, and which is suitable for being assembled together with the modular tile 1 for the construction of building structures. For example, a fraction 200 may be used at the end of an intermediate and the relative lateral sections 3 may be inserted inside a hollow 4 of two modular tiles 1 in two adj acent rows .

As is illustrated in FIGURES 10 and 11, each modular section M2' creates a fraction 200' of modular tile which is conceptually identical to the modular tile 1 as regards all the characteristics which have been described so far, and which is suitable for being assembled together with the modular tile 1 for the construction of building structures. For example, a fraction 200' may be used at the end sides of an initial row at the bottom of a wall, or of a last upper row of the wall itself, and the relative lateral sections 3 may be inserted inside two hollows 4 of two modular tiles 1 in a row adjacent to the first or last one. Furthermore, by uniting two modular sections M2 along the sides L2 , or two modular sections M2 ' along the sides LI it is possible to create the original modular unit Ml, that it is to say the modular tile 1. As is illustrated in FIGURES 12, by uniting two modular sections M2 along the side L_min it is possible to create another alternative modular tile 300, which differs from the modular tile 1 for the fact that each side L3 and each half hollow 4 are swapped so that the central section 2 of each modular section M2 is arranged close to the central section 2 of the other modular section M2 and the lateral section 3 of each modular section M2 is arranged opposite to the lateral section 3 of the other modular section M2 with respect to the relevant central section 2. In this way, the modular tile 300 is provided along the axis Al with an external outline which is complementary to the outline of the modular tile 1 along the same axis Al . As is illustrated in FIGURES 13, by providing each external long sides of the modular tile 300 with a respective hollow 301 it possible to obtain another alternative modular tile 300' with four hollows 301 placed just next the axis Al and the axis A2. The dimension of each hollow 301 along the relevant axis Al, A2 is a half of the dimension of the same hollow 301 along the other axis A2 , Al, and each hollow 301 defines a seat for a small tile 302 whose shape is quadrangular . Finally, as is illustrated in FIGURES 14, by providing each sides L_min and each hollow 4 of the modular tile 1 with a respective hollow 401 it possible to obtain another alternative modular tile 400 with four hollows 401 placed just next the axis Al and the axis A2. The dimension of each hollow 401 along the relevant axis Al, A2 is a half of the dimension of the same hollow 401 along the other axis A2 , Al , and each hollow 401 define a seat for a small tile 402 whose shape is quadrangular. The construction of a wall by means of the use of the modular tiles 301 or 401 gives to the wall a more reliable and solid structure.

The modular tile 1 has got eight sharp edges E whereas the modular tile 301 and the modular tile 401 have got sixteen sharp edges E, and by varying the number of edge E it is possible to obtain different kind of modular tiles whose simplest example is given by the modular tile 1.

It is obvious from the above description that each of the modular sections M2, M2 ' and M4, or that is to say the fractions 200, 200' and 100, can be constructed as individual units or by dividing a modular tile 1, which may be made of steel or clay by using a mold in which the channels 8 and 9 are defined by tubular elements in the mold itself, while the channels 14 are defined by further tubular elements which are subsequently introduced inside the mold by means of the preceding tubular elements.

The construction of a wall by means of the use of the modular tiles described above may be carried out extremely simply and rapidly, without any kind of inconvenience regarding the linear and vertical nature of the wall itself. In particular, every time that a row of modular tiles has been finished, a semi-liquid material such as mortar may be injected via the channels 8 and 9 in order to completely fill the interior of the modular tile 1 and this operation may be carried out row by row until the wall is completed. This filling operation may be carried out extremely quickly and it means that the resulting building structure is more solid in comparison with the kind of building structures currently being constructed, and this kind of filling operation may be carried ^' out using materials other than mortar, such as material that will improve the wall's insulation capacity in terms of heat and soundproofing .

In the case that cables for electrical or telephone services have to be installed along the wall, flexible tubular conduits for housing the cables themselves may be inserted by means of the channels 14 before any mortar is injected. These conduits are connected to the outside by means of junction boxes which are housed in respective seats which are obtained through a wall 5 of the modular tile 1. These seats are not illustrated.

The modularity of the modular tile 1 and of its derivative modular sections means that it is possible to construct any kind of wall without wasting any building material, due to the fact that all the necessary elements may by easily estimated and accounted for when the wall itself is being planned. Using the modular tile 1 thus means that it will no longer be necessary to divide the modular tile 1 itself during the construction phase in order to obtain cropped sections, which are generally of an irregular shape, and which results in considerable wastage in terms of man hours and building material .

On the other hand, _. in the case in which building work must be carried out in pre-existing situations, that is , to say when the external structure in not planned with the use of the modular tile 1 in mind, the structure of the modular tile 1 is such that it is possible to carry out any kind of adjustment in a much shorter time than is currently possible, as it is sufficient to use a simple flexible cutter, which is usually to be found on all building sites, in order to cut cropped sections from the modular tile 1, or from one of its modular sections . In the case in which the modular tile 1 or its modular sections have to be used for the construction of a floor, the modular tile 1, instead of presenting two projecting edges 10 for each side L^, will be provided with a single projecting edge 10, which is arranged towards the lower end. The lack of one projecting edge 10 means that it is possible to leave free the upper spaces between one modular tile 1 and another, in such a way that during the casting of the cement, the cement may penetrate inside the channels 8, 9 and 14 in such a way as to render the floor even more solid. Furthermore, reinforcement of the floor can be easily carried out by introducing iron rods through the channels 8, 9 and 14 before the casting of the cement. It is clear, from what has just been explained, that the use of the modular tile 1 considerably simplifies and speeds up the construction of a floor without, however, compromising any of its technical features.

By miniaturizing the dimensions of the modular tiles above described and, furthermore, by changing the material, it is also possible to make building structures particularly suitable for the games of children.

It is intended that the present invention not be limited to the forms of embodiment herein described and illustrated, which are to be considered as examples of preferred forms of embodiment for a modular tile for building structures, and which may be subject to further modifications in terms of the shape and arrangement of parts, constructive details and assembly.

Claims

1. Modular tile (1) for building structures characterised by the fact that it comprises a first L-shaped modular section (M4) which is provided with a longer and a shorter side (LI, L2) forming a right angle in relation to each other, and of which the longer side (LI) has a greater length than the shorter side (L2) .

2. Modular tile according to Claim 1, characterised by the fact that the first modular section (M4) presents two further external sides (L3) which are parallel to each other and to the longer side (LI) and the length of which is equal to half the length of the longer side (LI) itself; the two external sides (L3) are staggered in relation to each other.

3. Modular tile according to Claim 2, characterised by the fact that it comprises a second modular section (M4) which is identical to the first modular section (M4) , and which is arranged laterally to the first modular section itself along a first side (LI) (L2) of the said two sides (LI; L2) in order to form a third modular section (M2) of the modular tile itself; the third modular section (M2) presents a respective external side (L3) which is defined by the linear sum of a second side (LI) (L2) of the said two sides (LI; L2) .

4. Modular tile according to Claim 3 , characterised by the fact that the first and second modular sections (M4) are arranged next to each other along the longer side (LI) ; the third modular section (M2) presenting a plan view in the shape of an L.

5. Modular tile according to Claim 3, characterised by the fact that the first and second modular sections (M4) are arranged next to each other along the shorter side L2 ; the third modular section (M2) presenting a plan view in the shape of a C.

6. Modular tile according to Claims 4 or 5, characterised by the fact that it comprises a fourth modular section (M2) which is identical to the third modular section (M2) and which is arranged laterally to the second modular section (M2) itself along the said second side (L2) (LI) to form a modular unit (Ml) which presents, in a plan view, the shape of a double T.

7. Modular tile according to Claim 6, characterised by the fact that it comprises: a longer symmetrical axis (A) and a shorter symmetrical axis (A2) which are at right angles to each other and which define on the modular unit (Ml) itself four identical modular sections (M4) ; and a number of internal lightening channels (8, 9) which are parallel to at least two symmetrical axes.

8. Modular tile according to Claim 7, characterised by the fact that it comprises: two flat walls (5) , which are arranged on respective planes which are parallel to each other and to a lying plane (P) which is formed by the two symmetrical axes (Al, A2) , and presenting a shape in the form of a double T on the lying plane P itself; and a number of connecting baffles (6, 7) between the two walls (5) themselves which are arranged parallel one of the two symmetrical axes.

9. Modular tile according to Claim 8, characterised by the fact that it comprises two lateral baffles (6) and three pairs of internal baffles (7) which define, in relation to each other and to the lateral baffles (6) themselves, seven channels (8, 9) which are parallel to each other.

10. Modular tile according to Claim 9, characterised by the fact that three channels (8) of the said seven channels (8,9) present a substantially square shape in a section at right angles to the shorter symmetrical axis (A2) , and four channels (9) of the said seven channels (8,9) present a substantially rectangular shape in a section at right angles to the shorter symmetrical axis (A2) .

11. Modular tile according to Claim 10, characterised by the fact that it comprises four further internal connecting baffles (12) between the two walls (5) which are arranged through the said four rectangular-shaped channels (9) .

12. Modular tile according to Claim 11, characterised by the fact that each baffle (6, 7, 12) presents at least three passing holes (13) and defines, along with the passing holes (13) of the other baffles (6, 7, 12) respective passing conduits (14) which are parallel to the longer symmetrical axis (Al) .

13. Modular tile according to Claim 12, characterised by the fact that each baffle (6, 7, 12) presents five passing holes (13) and defines, with the passing holes (13) of the other baffles (6, 7, 12) respective passing conduits (14') which are parallel to the longer symmetrical axis (Al) .

14. Modular tile according to Claim 9 or 10, characterised by the fact that the said two walls (5) comprise a number of projecting edges (10, 16) which are suitable for defining further passing channels (11, 17) which are parallel to either the longer axis (Al) or the shorter axis (A2) .

15. Modular tile according to any of the above Claims from 8 to 14, characterised by the fact that each of the said walls (5) comprises a determined number of extra channels (15) for purposes of lightening which are arranged parallel to the shorter symmetrical axis (A2) and which are subdivided into groups created by the four rectangular channels (9) .

16. Modular tile according to Claim 15, characterised by the fact that each group of extra channels comprises two extra channels (15) .

17. Modular tile according to Claim 15, characterised by the fact that each group of extra channels comprises four extra channels (15) .

18. Modular tile according to Claim 7, characterised by the fact that the longer side (LI) presents a length which is twice the length of the shorter side (L2) .

19. Modular tile according to Claim 7, characterised by the fact of presenting an overall length (l_max) measured along the longer axis which is equal to twice the length of the longer side (LI) .

20. Modular tile according to Claim 19, characterised by the fact that the said external sides (L3) present a length which is equal to a quarter of the overall length (l_max) and are staggered in relation to each other at a distance equal to a third of their length.

21. Modular tile according to Claims 7, characterised by the fact that it comprises a fourth modular section (M2) which is identical to the third

modular section (M2) and which is arranged laterally to the second modular section (M2) itself along a respective longer side (L_min) to form a modular tile

(300, 300') which presents two opposite lateral portions (3, 3) shorter than the two respective central portions (2, 2) along the shorter symmetrical axis (A2) .

22. Modular tile according to Claim 21,

characterised by the fact that each external side is provided with a respective hollow (301) the dimension of which along the relevant axis (Al) (A2) being a half of the dimension of the same hollow (301) along the other axis (A2) (Al) .

23. Modular tile according to Claim 22, characterised by the fact that each hollow (301) defines a seat for a quadrangular tile (302) .

24. Modular tile according to Claim 7, characterised by the fact that it is provided with at least four hollows (401) placed just next the two axis (Al, A2) .

25. Modular tile according to Claim 24, characterised by the fact that the dimension of each hollow (401) along the relevant axis (Al) (A2) is a half of the dimension of the same hollow (401) along the other axis (A2) (Al) .

26. Modular tile according to Claim 25, characterised by the fact that each hollow (401) defines a seat for a quadrangular tile (302) .

27. Modular tile according to Claim 7, characterised by comprising at least eight external edges (E) in a plan view.

28. Modular tile according to Claim 7 or 23 or 26, characterised by comprising a plurality of external edges (E) whose number is more than eight and it is, in a plan view, at least sixteen.

29. Modular tile according to Claim 7 or 23 or 26, characterised by the fact that miniaturizing the dimensions of the same modular tile it is possible to make building structures particularly suitable for the games of children.

30. Modular tile according to any of the above Claims from 15 to 16, characterised by the fact that one of the two walls (5) has got a double thickness with respect to the other wall (5) and it is provided with a double number of extra channels (15) .

31. Modular tile according to Claim 30, characterised by the fact that the extra channels (15) in the wall (5) with the double thickness are arranged in two parallel rows.