Abstract:
The invention relates to horizontally and vertically linked paving stones ( 10 ). According to the invention, projections ( 18 ) and recesses ( 19 ) are provided in the area of the bottom part ( 16 ) of the paving stones ( 10 ) used for a paved surface in order to link said paving stones horizontally and vertically. These projections and recesses engage with each other with a positive fit so as to interlock adjacent stones in a horizontal and vertical direction. The paving stones ( 10 ) are characterised in that the width of the joints ( 32 ) formed between adjacent paving stones ( 10 ) increases in a downward direction so as to form a gap which diverges downwards. This means that the material used for filling the joints can be introduced efficiently and reliably as far as the underside.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a (concrete) paving stone for producing surfacings over the ground, in particular paved surfaces, the paving stones being laid with (longitudinal and transverse) joints being formed between adjacent paving stones and the joints being filled with joint filling material. The invention also relates to a set of paving stones and a device for producing paving stones for curved sets. 
     The forming of paving stones from concrete has to meet increasingly high requirements. The outer appearance is to be attractive. Nevertheless, the paving stones are to form a surfacing over the ground that is resistant to rolling traffic loads by vertically and horizontally interlocking with adjacent paving stones—horizontal and vertical linkage. The invention is concerned with paving stones which ensure by the way in which they are formed a horizontal linkage and a vertical linkage within the paved surface. It deals with the special forming of such paving stones and the production of paving stones for curved sets. 
     SUMMARY OF THE INVENTION 
     The invention is based on the object of designing paving stones with horizontal linkage and vertical linkage in such a way that a supporting, load-bearing surfacing over the ground can be produced and special configurations of paved surfaces are possible. 
     To achieve this object, the paving stone according to the invention is characterized in that the joints formed between the adjacent paving stones have on account of appropriate shaping of side surfaces of the paving stones a cross section diverging downwards from an upper side of the stone to an underside of the stone. 
     The way in which the paving stone is formed according to the invention ensures that the longitudinal joints and/or transverse joints between the adjacent paving stones permit reliable filling with joint filling material, in particular sand and/or gravel. According to the invention, the gap width of the joints increases downwards, so that wedging of particles of the joint filling material is avoided. Wherever the joints are bounded by corresponding sloping surfaces of the paving stones, they have an angle which is less than the angle of repose of the joint filling material, in other words in particular less than 30°. 
     Furthermore, it is envisaged that the paving stones are provided with spacers at certain, selected regions of the side surfaces, to be specific exclusively in the region of a lower part of the stone. 
     For forming a paved surface with obliquely directed rows of paving stones, a set of edge stones according to the invention is proposed. 
     Finally, the invention comprises the special shaping of a concrete stone mould for the production of wedge-shaped paving stones. For this purpose, according to the invention moulding ridges are arranged on a pulling plate, converging in the pulling direction of the said plate. In a corresponding way, the (wedge-shaped) paving stones of different sizes are arranged in rows in such a way that the (transverse) dimensions decrease in the pulling direction of the pulling plate. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     Further details of the invention relate to the shaping of the paving stones or sets and to the device for producing the same. Exemplary embodiments of the paving stones, the sets and the device are explained in more detail below with reference to the drawings, in which: 
     FIG. 1 shows a paving stone with horizontal and vertical linkage in plan view, 
     FIG. 2 shows the paving stone according to FIG. 1 in a view from an underside, 
     FIG. 3 shows a cross section through the paving stone according to FIG.  1  and FIG. 2 in a central transverse plane, 
     FIG. 4 shows a cross section through the paving stone according to FIG.  1  and FIG. 2 in a lateral transverse plane, 
     FIG. 5 shows a detail of a paved surface, to be specific two adjacent paving stones, in vertical section, 
     FIG. 6 shows a portion of a paved surface in plan view, 
     FIG. 7 shows the paved surface according to FIG. 6 in a view from below, 
     FIG. 8 shows a paving stone, to be specific an edge stone, for a paved surface according to FIG. 7 in a view from below, 
     FIG. 9 shows a further edge stone for the paved surface according to FIG. 7 in a view from below, 
     FIG. 10 shows a set of paving stones, to be specific a curved set, in a view from below, 
     FIG. 11 shows a device, to be specific a stone mould, for producing paving stones in plan view, 
     FIG. 12 shows a detail of the device according to FIG. 11, to be specific a pulling plate, likewise in plan view, 
     FIG. 13 shows the pulling plate according to FIG. 12 in cross section, 
     FIG. 14 shows paving stones resting on a pulling plate in cross section. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 to FIG. 5 show details of a concrete paving stone  10  designed in a special way. It is of a rectangular design in horizontal projection, with longitudinal sides  11  and  12  and transverse sides  13  and  14 . In the region of the longitudinal sides  11 ,  12 , the paving stone  10  is “interlocked” by projections and depressions in such a way that adjacent paving stones  10  within a paved surface are laid such that they are linked in the horizontal and vertical directions (horizontal and vertical linkage). The upright transverse sides  13  and  14  on these paving stones  10  are formed with a smooth surface, in other words without a linking effect. 
     The paving stone  10  comprises an upper part  15  of the stone and a lower part  16  of the stone. The upper part  15  of the stone is of a rectangular design in plan view, or is provided with a rectangular upper side  17  of the stone. 
     The underside  16  of the stone has projections and depressions, which permit the mutual interlocking of adjacent paving stones  10  and consequently the horizontal and vertical linkage. This linkage is not evident from outside or above when laying of the paved surface has been completed (for example FIG.  7 ), because the upper sides  17  of the stones are exclusively of a rectangular design, for example. 
     In the case of the present exemplary embodiment, the lower part  16  of the stone is provided in the region of one longitudinal side  11  with a central protection  18 . Formed opposite this is a correspondingly designed depression  19 . Projection  18  and corresponding depression  19  are trapezoidally formed, in other words with an outer surface  20  running parallel to the longitudinal side  11  and a corresponding inner surface  21  as well as with likewise corresponding obliquely running flanks  22 ,  23 . The projection  18  includes lateral corner depressions  24  and respectively corresponding corner projections  25  as a (part) limitation of the depression  19 . 
     The transition from the (rectangular) upper part  15  of the stone to the complexly formed lower part  16  of the stone takes place over obliquely running intermediate surfaces, to be specific sloping surfaces  26  in the region of the corner depressions  24  on the one hand and a sloping surface  27  in the region of the depression  19  on the other hand. Sloping surfaces  28 ,  29  are also respectively formed between the projection  18  on the one hand and the upper part  15  of the stone on the other hand and between the corner projections  25  on the one hand and the upper part  15  of the stone on the other hand. The latter can be seen in a plan view of the paving stone  10  (FIG.  1 ), whereas the sloping surfaces  26 ,  27  appear as visible surfaces in a view of the paving stone  10  from below (FIG.  2 ). 
     The paving stones  10  laid to form a paved surface (FIG. 5, FIG. 6, FIG. 7) are mutually interlocked with one another. The projection  18  of one paving stone  10  enters the depression  19  of an adjacent paving stone with a positive fit. In the same way, the corner projections  25  protrude into corner projections  24  of an adjacent paving stone  10 . The vertical offset between the upper part  15  of the stone and regions of the lower part  16  of the stone additionally produces vertical linkage because the sloping surfaces  26  bear against the sloping surfaces  29  and the sloping surface  27  bears against the sloping surface  28 . 
     Upright stone surfaces  30  of the upper part  15  of the stone and stone surfaces  31  of the lower part  16  of the stone are designed—in a way similar to sloping surfaces  26  . . .  29 —in such a way that the laid paving stones  10  form joints diverging downwards, in other words widening downwards from the upper side  17  of the stone. This applies in particular to longitudinal joints  32  in the region of the interlocking and expediently also in an analogous way to transverse joints  33  in the region of smooth-surfaced, approximately vertical transverse sides  13 ,  14 . For this purpose, the relevant stone surfaces of the paving stones  10  lying opposite one another for forming a longitudinal joint  32  or a transverse joint  33  are made to be slightly oblique with respect to an (imaginary) vertical plane, for example by an angle of 1° to 2°. The region of the sloping surfaces  26  . . .  29  is designed in an analogous way, in other words likewise with a gap widening gradually downwards. Furthermore, the inclination of the sloping surfaces  26  . . .  29  is chosen such that the angle of inclination with respect to an (imaginary) vertical plane is not greater than the angle of repose of joint filling material, in other words for example sand or gravel. This means that in practice the angle of the sloping surfaces  26  . . .  29  is not greater than 30°. This downwardly opening cross-sectional form of the joints ensures trouble-free introduction of the joint filling material over the complete height of the joints. 
     To ensure an exact relative position of the paving stones  10  within a paved surface, spacers are moulded on at selected positions. These are located exclusively in the region of the lower part  16  of the stone, and are accordingly not visible from the upper side of a paved surface. 
     In the case of the present exemplary embodiment, two spacers  36  are arranged at a distance from one another on the outer surface  20  of the projection  18 . These bear against an adjacent paving stone in the region of the depression  19 . Furthermore, the two corner projections  25  are respectively provided with a spacer  37 . Smaller spacers  38  and  39  are provided on the flanks  22  and  23  of the projection  18  on the one hand and the depression  19  on the other hand. The spacers  38  on the one hand and  39  on the other hand are positioned in such a way that they lie at a distance from one another when the paving stones have been laid. Finally, a spacer  40  is provided on each transverse side  13 ,  14 . These spacers  40  are also positioned in an offset manner, so that they respectively bear against adjacent paving stones  10  at a distance from one another. 
     A further special feature is revealed by FIG. 6 to FIG.  9 . Here, paving stones  10  are laid in obliquely directed rows  41  of stones. FIG. 6 shows a view from the upper side  17  of the stones, FIG. 7 shows a view from below with the horizontal and vertical interlocking. 
     Edge stones  42 ,  43  are designed in a special way. To ensure interlocking or linking up to straight, parallel edges of the paved surface, the edge stones  42 ,  43  are designed in the region of the lower part  16  of the stone in such a way that they in each case adjoin with a positive fit to obliquely directed rows  41  of stones and form a straight termination on the outer side. In the region of the upper part  15  of the stone, the edge stones  42 ,  43  are of a coinciding design, to be specific with a rectangular subregion and a triangular subregion (FIG.  6 ). The triangular region in this case adjoins two adjacent rows  41  of stones. 
     The lower part  16  of the stones are of a differing design. In the case of the edge stone  42  (FIG.  8 ), there is formed a part-projection  44 , which enters with a fit into the region of a corner depression  24  of an adjacent paving stone  10 . The other edge stone  43  is instead provided with a corner projection  45 —analogous to the corner projection  25  of a paving stone. The corner projection  45  enters—with a corner projection  25  of an adjacent paving stone  10 —into a depression  19  of a paving stone  10  of the adjacent row  41  of stones. 
     This shaping of the edge stones  42 ,  43  applies to laying of the paving stones  10  with the rows of stones  41  offset in relation to one another. The paving stones  10  are laid with a half-bond, two corner projections  25  of adjacent paving stones  10  respectively entering into a depression  19  of a paving stone  10  of the adjacent row  41  of stones. 
     A further special feature concerns the shaping and production of paving stones with converging longitudinal sides  11 ,  12 , to be specific curved stones. A set of geometrically matching curved stones  46 , to be specific increasing in the transverse dimension in a wedge-shaped manner, produces a curved set  47  according to FIG.  11 . By laying a number of curved sets  47  next to one another, a paved surface can be produced along an arcuate route. 
     In the present case, both longitudinal sides  11 ,  12  of the curved stones  46  are obliquely arranged, in other words running in a wedge-shaped manner. This applies both to the upper part  15  of the stone and to the lower part  16  of the stone. As a result, a full linking effect, that is with horizontal and vertical linkage, is obtained in the region of the curved sets  47  as well. 
     One special feature is the production of such curved stones  46 . Concrete stones are usually produced in concrete moulds which have a number of mould cavities that are open at the top and bottom. These are filled with the fresh concrete. On the underside, the mould cavities are closed by an underlay board. Mould dies enter the individual mould cavities from above, to ensure an upper limitation for the concrete stones. 
     FIG. 11 shows such a concrete mould in plan view. The mould cavities  48  are designed in such a way that the upper part  15  of the stone, in other words the upper side  17  of the stone, is facing downwards and the lower part  16  of the stone with the interlockings is facing upwards. Mould dies which have the contour of the lower part  16  of the stone in horizontal projection enter the mould cavities from above. The lower part  16  of the stone rests on a special pulling plate  49 , a plate-shaped, thin-walled element which is pulled out to the side after moulding of the paving stones  10  or the curved stones  46  within the mould cavities  48 , so that after that the (fresh) stones rest on the underlay (underlay board) lying underneath. The pulling plate  49  has the task of moulding the regions of the upper part  15  of the stone on the longitudinal sides  11 ,  12  and also the undercuts, that is the sloping surfaces  28  and  29 . 
     For this purpose, moulding ridges  51 , running in the direction of the pulling movement according to arrow  50 , are arranged on the upper side of the pulling plate  49 . These are upright ribs which run transversely with respect to the pulling plate  49  and, with side surfaces, mould the form of a lower subregion of the paving stones  10  or curved stones  46 , to be specific the upper part  15  of the stone. For this purpose, the moulding ridges  51  are of a roof-shaped design in the upper cross-sectional region. The sloping moulding surfaces  52  thus formed bear against undercut or downwardly directed sloping surfaces  28 ,  29  (FIG.  14 ). The upwardly directed sloping surfaces  26 ,  27 , on the other hand, are moulded by the individual moulding dies (not shown) assigned to each mould cavity  48 . 
     The pulling plate  49  is in the present case set up for the forming of curved stones  46 . For this purpose, the moulding ridges  51  have a cross-sectional form diverging in the pulling direction (FIG.  14 ). The width of the moulding ridges  51  increases in the pulling direction. Corresponding to this forming of the moulding ridges is the positioning of the mould cavities  48  within the concrete mould (FIG.  11 ). The mould cavities, arranged in longitudinal and transverse rows, are distributed with regard to size in such a way that the transverse dimension of the wedge-shaped curved stones  46  decreases in the pulling direction according to arrow  50 . Accordingly, in each transverse row  53  of the mould cavities  48  the width decreases in the pulling direction according to arrow  50 , to be precise in a wedge-shaped manner, so that moulding ridges  51  of a correspondingly wedge-shaped design respectively bear with a width increasing in the pulling direction against the mutually facing longitudinal sides  11 ,  12  of the curved stones  46  of adjacent transverse rows  53 . This relative position also makes trouble-free demoulding possible, to be specific pulling out of the pulling plate  49  in the direction of the arrow  50 . The width of the moulding ridges  51  decreasing counter to the pulling direction allows the said moulding ridges to be pulled out between the transverse rows  53 . When this happens, the form of the longitudinal sides  11 ,  12  in the region of the lower part  16  of the stone and the undercut sloping surfaces  28 ,  29  is preserved. After pulling away the pulling plate  49 , the mould frame is raised, then the mould dies. The underlay board (not shown) can then be conveyed away with the wedge-shaped concrete stones in the usual way. 
     The design principle of the concrete mould and the pulling plate  49  can also be used in the case of differently formed wedge-shaped concrete stones with undercuts. 
     List of Reference Numerals 
       10  paving stone 
       11  longitudinal side 
       12  longitudinal side 
       13  transverse side 
       14  transverse side 
       15  upper part of stone 
       16  lower part of stone 
       17  upper side of stone 
       18  projection 
       19  depression 
       20  outer surface 
       21  inner surface 
       22  flank 
       23  flank 
       24  corner depression 
       25  corner projection 
       26  sloping surface 
       27  sloping surface 
       28  sloping surface 
       29  sloping surface 
       30  surface of stone 
       31  surface of stone 
       32  longitudinal joint 
       33  transverse joint 
       36  spacer 
       37  spacer 
       38  spacer 
       39  spacer 
       40  spacer 
       41  row of stones 
       42  edge stone 
       43  edge stone 
       44  part-projection 
       45  corner projection 
       46  curved stone 
       47  curved set 
       48  mould cavity 
       49  pulling plate 
       50  arrow 
       51  moulding ridge 
       52  moulding surface 
       53  transverse row.