US2605681A - Paving block - Google Patents

Description

Aug. 5, 1952 Filed July 28, 1949 V. TRIEF PAVING BLOCK 2 SHEETS-SHEET 1 5, 1952 v. TRIEF 2,605,681

PAVING BLOCK Filed July 28, 1949 2 SHEETS-SHEET 2 Patented Aug. 5, 1952 UNITED STATES PATENT OFFICE PAVING BLOCK Victor Trief, Deux-Acren lez Lessines, Belgium Application July 28, 1949, Serial No. 107,168

In France July 31, 1948 1 Claim. 1

, one another when placed side by side, said bosses and hollows being provided owing to the fact that the block has one portion of its thickness of rectangular form and, the remainder of its thickness, of a different geometrical shape, the two portions being united by faces parallel or inclined with respect to the upper and lower faces of the block. The blocks support each other in the same plane and may be laid upon a simple layer of sand without necessitating rigid foundations. They further offer the great advantage that the load applied to one block is distributed over several blocks owing to their mutual interfitting. V

a The invention relates to a paving block of simple and expedient shape, that shows to the highest degree such advantages as are requested when using paving blocks of that type. The paving block of the invention is essentially characterized by the fact that the non-rectangular portion has a contour, two opposite sides of which show each a whole regular, full wave with the corresponding side of the rectangle as abscissae axes, the waves being arranged symmetrically to the corresponding geometrical axis of the base rectangle, the two other opposite sides being formed by parallel half waves.

The arrangement is such that the convex portions of the full waves are adjacent the concave side comprising one half wave. The waves preferably are of sinusoidal form. Some orall of the sine curves may be replaced by arcs ,of a circle. Further according to the invention, the tangents at the points of origin of adjacent curves that meet at the angles of the base rectangle are preferably perpendicular to each other, such tan-.

gents forming preferably an angle of 30 with the corresponding sidesof the base rectangle.

Among the advantages of the invention it should be mentionedthat it enables effective interfitting of the paving block with adjoining blocks all over the periphery thereof, it is to say, on the four sides of the base rectangle, while each boss cooperates with one single corresponding notch of an adjoining block and will never become located at the joint between two adjacent blocks. Thus, the distribution of the load over the blocks is effected in the best possible manner. Paving blocks of the aforesaid type may, if strictly necessary, be laid without jointing, and so that the bosses of one block rest directly upon corresponding bearing faces of the adjoining 2 blocks. However, owing to unavoidable imper fections in the manufacture of the blocks and in the laying operation, such method is detrimental from the standpoint of a good transmission of the stresses in view of distributing the load and is liable to cause local overloads capable to bring about untimely destruction of the pavement. According to the invention, these drawbacks may be eliminated in that the faces uniting the rectangular portion of the block to the non-rectangular portion thereof are so arranged that a packing of sand or the like is formed between them after the blocks have been interfitted. Further according to the invention the said uniting faces are advantageously of such slope that the joint widens out somewhat downwardly and opens into a joint, likewise widening out downwardly and provided between the rectangular portions of the paving blocks so as to facilitate the packing in of sand. I

Other features and advantages of the invention will appear from the disclosure of one embodiment of "the invention,,which will be given hereinafter by way of example with reference to the accompanying diagrammatic drawings, in which:

Fig. 1 is a perspective view of a paving or road surfacing block according to the invention;

Fig. 2 is a plan view of the paving block;

Fig. 3-is a plan view of a portion of a pavement. executed according'to the invention;

Fig. 4 is a vertical sectional view of adjacentportions of two paving blocks;

Fig. 5 is a plan view of the lower part of a mould according to the invention intended for producing blocks of the kind specified; I

Fig. 6 is a sectional view on linue VIVI 0 Fig. 5;

Fig. 7 is a plan view of the upper part of the mould, and

Fig. 8 is a section on line VIII-VIII of Fig. '7, the two parts of the mould being superimposed.

In the drawings, l indicates the rectangular portion of the paving block, the sidesof which are in a ratio of about 4/5, while 2 indicates the non-rectangular portion. The two portions may have the same thickness or not. In the example illustrated, the thickness of the non-rectangular portion is about 8/5 that of the rectangular portion, such proportion having proved advantageous in the course of the tests.

The portion 2 has two opposite sides each formed by a full sine wave or the like 3, 5, the two sides being symmetrical with respect to the axis A-A of the paving block. The two other opposite sides 5, 6 are superposable by translation along the axis A-A. The paving block thus includes two bosses corresponding to the bearing faces 8 and a boss 9 corresponding to the bearing face [0. The interfitting of the paving blocks is thus effected along the four sides and transmission of the load to adjoining blocks takes place through the bosses 'i' and 9, which take half the periphery. Each boss rests upon one single bearing face of an adjoining block, whereas, if the boss was to rest upon complementary bearings of two adjoining blocks, the joint between the latter would constitute a lost surface with regard to the transmission of-stresses resulting from the load.

It will also be seen that the mutual'thrust of the paving blocks takes place in three points, which is the ideal solution for securing a uniform distibution of the load in all directions.

Advantageously, the centres of the three bear: ing facesform the apices of a substantially equilateral triangle, which ensures a perfect distribution of the load. This is especially the case in the example illustrated, where the dimensions of the-sides of the base-rectangle are ina-proportion of about' l/5, e. g. x cm. Moreover, since the bosses'occupy half the periphery, the surface employed fortransmitting the stresses due to the load-is as large as possible, so that'the cutting stress upon the bosses is reduced to a minimum. Further, it should be noted that the block has 'no unsupported pointed portions, which'are always breakable and get easily damaged during transport and handling. It will therefore be seen that the paving block of the invention is' particularly suitable for roads with hard andheavy-weight traflic.

The waves forming the contour of the portion 2 are advantageously of sine shape. They may be replaced, however, by arcs of a circle. With the same tangent at the point of origin, such arcs of a1 circlewill have a smaller trackl. or maximum set-off, which slightly reduces the surface of" the. boss. portions 9, I0 is'l'arger than that of the portions 1, 8, assuming that the curves confining them are of the same nature, 'one may, for instance, maintain the. sine curves 3, 4; but replacelthe curves 5, 6'" by arcsof a circle, if one wants to obtain substantially equal tracks=on'the four I sides of the block.

The curves confining the portion 2 are preferably so established-that the angles B; and. C formedby their tangents at the point of origin 'withthe sides of the rectangle l areequal toeach other and have advantageously a value of about so that the block has four right angles. It will be understood that the bearing "faces 8,10 and the lower'faces of the bosses], Q'may be parallel to the'upper and lower surfacesof the block. However; as "shown in Fig. 4=;-it is preferable toimpart them a'slant upwardly from the rectangular portion I, the inclination ofthe bearing faces 8, Hi being slightly sharper, so as to obtairr a joint il widening out somewhat downwardly. Moreover, the lateral faces of the portion I, instead of being vertical, are. preferably 'inclinedslightly inwardly 'of the paving block from their meeting point with the portion 2 of the'block, so as to form joints widening out downwardly. It will be seen that the above arrangementena'bles an easy packing of the joints 1 I; I2 with sand or'the likenv It is'also useful to Since the track of; the

provide a thinasphalt orlike packing" 13 between to its depth by the presence of the sand pack-' ing ll.

Figs. 5 to- 8 illustrate a mould for producing paving or road surfacing blocks of the kind described. It is formed of two parts, the lower (Figs. 5-6) of which includes a rectangular frame 14 supporting a frame l5 corresponding to the contour of the upper portion of the block, and a removable bottom wall [6 that 'fit's into the frame l5. The latter is provided with three flanges ll, I8 corresponding to the bearing faces 8, IU of the block and having a corresponding slant.

The upper-part. of the mould (Figs. 7-8) includes a rectangular frame I 9 fitting exactly into the frame I4 and carrying a rectangular frame 20 corresponding to the contour of the lower portion of the block, the faces thereof being slightly inclined on the vertical. At its bottom portion the, frame 20 is provided with three flanges 2|, 22 corresponding in shape and inclination to the bearing faces of thebosses I, 9 of the upper portion of the block.

' The moulding of a paving block is effected as follows. The two parts of, the mould are super imposed as shown in Fig, 8 and the assembly is placed upona vibrating table. The mould is filled with concrete and the vibration is set up. Whenthe vibration is finished, the upperpalt is removed, this being easily disengaged especially if. the walls of the frame 28 are inclined as shown in the drawing. The unit comprising the moulded block and the lower part of the mould is then turned upside down on the floor, and the latter part of the mould is removed very easily, since the removable bottom wall I6 is sticking to the upper face of the block. It is readily disengaged in turn by rotating it slightly in its own plane.

Thus, ,the mould enables to execute'in one step and in a verysimple-wayai blockwith lateral interfit portions, of intricate geometricflshape. This procedure is much more advantageous than the .one obtainedwith a vertically divided'mould', the partsof which have to be disen aged in' a horizontal direction during stripping and cannot practically be held perfectly in place during the vibration. This drawback does not appear with the mould of the invention, which ismoreover practically subject tono; wear and isf besides simpleuand cheapto manufacture. Moreover, it iseasy to produce a mould-having several corn1- partments 1 similar to the individual mould above described.v It will be understood that the mould of the invention is suitable not onlyfor the manufacture of blocks of the kind deseribed and illustrated,. but also for thatofany blocks comprising, in the direction of vtheirthickness, two portions having diiierentcontours projecting locally one with respect to 'the other. j

With reference to paving 1 blocks the said mouldingmethod hasthe further advantage that the upper face of the block, whichisthe ring face lays at the bottom of the mould, where 'the concrete of the. best quality is forming.

A. paving block, compr sin .a recta ular shap dl ase having, substantially strai ht side edge surfaces and end-edge surfacesat, right angles to saidside edge surfaces, an upper portion integral with said base, a convex'fendlsurface on the .upper portion overhanging one end'sur:

face 'ofthejbase. with the endsv of said conveg g surface vertically aligned wit twoendco'rners" of said base, a concave surface forming the other end edge of the upper portion and arranged parallel with said convex surface with ends of the concave surface vertically aligned with other end corners of said base, a side edge surface on the upper portion including a concave surface beginning at one end of said convex surface retreating inboard of one side edge of the base and merging with a similarly shaped convex surface overhanging the same side edge of said base and terminating at one end of the first concave surface, another side edge surface on the upper portion including a concave surface beginning at the other end of the first convex surface and retreating inboard of the other side edge of said base and merging With a similarly shaped convex surface overhanging the same side edge of the base and terminating at the other end of the first concave surface, the concave and convex surfaces at the sides of the upper portion forming opposed sinuous faces with areas of the upper portion defined by the convex edges adapted to fit into recesses defined by the concave surfaces of adjacent paving blocks, substantially horizontal bearing faces at the top of the base portion outboard of all of the concave surfaces, ledges on the upper portion defined by the convex surfaces thereon having substantially horizontal bearing faces thereunder extending inboard of the convex surfaces and adapted to lie on bearing faces of the base portion of adjacent paving blocks, the centers of support of said ledges being so located as to define apices of an isosceles triangle whereby three support areas are provided on the paving block.

VICTOR TRIEF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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