Expansion joint batten or packing of dilation joint

Abstract

A roadway expansion joint including an elongated elastomeric member having a plurality of transverse cylindrical cavities therein and a metal bar movably positioned in each cavity and spanning the roadway gap.

Description

The present invention relates to a joint packing or joint batten (batt plate or covering plate), consisting basically of an elastic material band, such as synthetic rubber or other appropriate material, such as synthetic elastomers, placed into the junctions of the joint proper of civil engineering works, such as bridges, roads, etc. It is particularly adapted to be used, when the joints of the works have a high coefficient of dilatation which is actually the case of bridges of great lengths; while previously dilatation (expansion) joints were provided in numerous places of the bridge, their number is actually strongly reduced which causes the use of packings of great widths.

The known solutions used in the case of bands of elastic material of a great width, which have the tendency to bulge or to collapse under the action of strong service stresses, have provided strengthening pieces, supporting strips, etc., placed and attached under the band of elastic material; these different additions increase the costs of these packings as well as the difficulty of their placing.

The present invention remedies these inconveniences by suggesting a joint of a concept and of an emplacement which is much simpler and which prevents simultaneously the whole danger of bulging and all the danger of collapsing.

The suggested expansion joint batten consists basically of a band of compressible material, as synthetic rubber, and other suitable elastic materials, as synthetic elastomers, in which a certain number of cavities (recesses) is provided, generally of round shape, crossing laterally the band of elastic material on its whole width.

These cavities are provided with irons or steel bars, generally of round shape, and the length of which is at most equal to the width of the band of plastic material of a maximum compression stress to which it has to respond; the width of the band of elastic material is, on the other hand chosen so as to be able to introduce into the cavities irons or steel bars, the length of which exceeds the width of the joint of dilatation (expansion) of the work in maximum contraction, so that these irons or steel bars form always a bridge on the joint of dilatation of the work.

The attachment to the work of a band of elastic material, conceived in this way, will be preferably effected at some distance from each lateral end of the band of elastic material, by metallic plates immersed into its end placed at a short distance in the prolongation of each other; these plates, comprising at least three perforations, a central one to which a screw head is welded and through which the fixation of the elastic band to the work will be realized. The two lateral perforations are of a sufficient dimension for allowing the introduction of irons or for steel bars of reinforcement of the band of elastic material.

Other characteristics and advantages of the present invention will appear from the following description which is given as a non limitative example in reference to the attached drawings which represent in:

FIG. 1 a view in cross-section of an expansion joint batten at the spot where a strengthening iron was placed,

FIG. 2 shows a sectional view in the length of an expansion joint batten along the line I/II of FIG. 1,

FIG. 3 shows a longitudinal sectional view of a joint batten along the line III/IV of FIG. 2,

FIG. 4 shows a cross-sectional view of a joint batten comprising a variant of fixation to the work, and

FIG. 5 shows a cross-sectional view of the joint batten comprising a variant of fixation to the work.

At FIG. 1, a member or band of elastic material 1 is represented in which one of several parallel recesses or cavities 2 of a round shape is shown, extending along the roadway and along the direction of dilatation of the expansion joint. As illustrated, the extension of member 1, longitudinally of the roadway and of cavities 2, is greater than the thickness or height of the member. In the cavity 2, an iron or steel bar 3 is slidably inserted, being of a length which is seen limited at a part of the length of the cavity 2, respecting the above indicated minimal and maximal conditions. These irons or steel bars can move in the cavities 2 and are not centered in them, but springs 5 are provided at each end, tending to center these irons or steel bars, or to keep account of the minimal length with a maximum displacement of these irons, when compressing the band of elastic material 1.

In the realizations shown in the drawings, particularly on FIGS. 2 and 3, cavities 2 are provided at each side of a point of attachment, but it is well assured that this number be not limitating, neither the respective shape of the cavities 2 and of the irons or steel bars, but the other further indicated constitutive elements of the joint batten have to be adapted in function of the number of retained cavities.

The band of elastic material 1 is provided in a known way at its upper face with longitudinal grooves 5 which decrease the force upon the anchorages, when it is set under traction. Equally, when this band of elastic material is put under pressure, the grooves 5 make the upper part of the band of elastic material 1 less resistant and a downward pull is necessarily created.

On the other hand, in order to permit this compression of this band of elastic material, cuts 6 longitudinal of band 1 are recessed into the lower part of the band which are of variable shapes and dimensions and are for example of one quarter of the dimensions of the uncut parts 7 of the band of elastic material 1. They are obtained at the moment of realization of the elastic material band 1; in effect, it proves to be indispensable to sustain during the casting of the material tubes permitting to realize the cavities 2.

Lower cuttings or grooves 8 (FIG. 2) have equally been provided in the lateral sense of the band of elastic material, nevertheless, these cuttings 8 are not provided on the whole width of the band of elastic material 1, but on a part of it only, for example a three quarters of the central part. A cutting 8 in a half circle has been adopted, but other shapes can also be used.

In order to permit the anchorage of the band of elastic material 1, a first series of metallic plates 9 has been immersed into it laterally at some distances from each end, placed at a short distance in the prolongation from one to the other and provided with three perforations (FIG. 2), a central one 10, mounted by a screw head 11, a part of which at least is inserted into the perforation 10, two other lateral 12, 13, of equal dimension as the outer diameter of the tubes provided to realize the cavities 2, and therefore, due to this fact itself, larger than the diameter of the irons or steel bars 3, and allowing their displacement.

The diameter of these perforations 12, 13 will preferably be even larger than the outer diameter of the said tubes, in order to permit, at the moment of casting of the band of the elastic material, that this material covers the inner circumference of these perforations 12, 13.

The band of elastic material 1, as it has been indicated above, is laterally squeezed, on the other side, by a second series of metallic plates 4, each forming (FIGS. 1 and 3) a side of a caisson (case) 14, or (FIG. 5) a side of a half-caisson or square 15, or (FIG. 4) being limited to the metallic plates 4. These metallic plates will be provided with perforations 16a, permitting (FIG. 4) the threaded end of anchoring bolts 16 to pass so that a bolt head 11, on one side and a nut 17 on the other side secure metallic plate 4 to the expansion joint.

In FIG. 5, the anchoring ironwork 18 is bolted on the horizontal part 4' of the square 15 and blocked by a bolt 19. Equally, in FIGS. 1 and 3, the anchoring irons 18 are blocked on the horizontal part 4' of the caissons 14 by means of the same bolt 19. The lower part 4' of the caisson 14 will be advantageously cut (punched) and a metallic plate (not represented) will then be placed astride upon the lower part 4' of the caisson 14, below the bolt 19, to correct a possible bad emplacement of the anchoring ironwork 18 or of the metallic plates 9.

In case of FIGS. 1, 3, the metallic plates 4 will be bolted to the metallic plates 9 by means of a threaded rod 20 and a bolt 21. In a variant of a not represented embodiment, the caissons 14 will be replaced by blocks of synthetic rubber, for example, provided with the perforations which are necessary for the passage of the bolts 19 and 21 as well as of the compressing (squeezing) tool.

In order to facilitate the introduction as well as the displacement of the irons or of the steel bars 3, their ends 3' will be rounded. Since due to shrinkage after the molding process the cavities 2 tend to close-up, they will not be perfectly rectilinear as shown on the drawings. Their form is also affected by stresses caused by compression or traction or changes of temperature. It has to be noted that the irons or the steel bars 3, which can be grooved or twisted in order to limit the force to which the anchorages will be submitted, allow displacements in opposite directions of the caisson parts of a roadbed, separated by the joint of dilatation.

The relatively short length of the metallic plates 9 permits to the joint batten (covering plate) to adapt itself to the profile of the work, such as a gutter or a sidewalk.

The present invention has been described above in detail with respect to the preferred embodiment thereof, however, it is to be understood that the present invention is not limited thereto. Various changes and modifications can be made without departing from the invention, for example, the bars 3 need not be steel or iron, other suitable material can be used. The bars 3 and the recesses or cavities 2 need not by cylindrical, they can have other shapes, such as other crosssections than circles. The bars 3 need not be straight and transverse; they can be crooked or curved and can be at an angle to the transverse direction. The bars need not be separate, they can be connected if desired. The recesses or cavities 2 need not have the same diameter as the bars 3; the cavity diameter can be formed larger or smaller than the bar diameter. The cavities need not extend completely through the elastomeric material 1, but can, for example, be closed at each end with elastomeric material.

Claims

I claim:

1. An expansion joint for a roadway, comprising:

a. an elastic member insertable between first and second roadway sections spaced apart widely in a direction along the roadway, the member having first and second portions, adjacent respectively said first and second roadway sections when in use, extending therebetween and being expandable and contractible in response to contraction and expansion, respectively of the roadway to reach from one of said roadway sections to the other, in said direction;

b. said member having a plurality of cavities, also extending substantially from one road section to the other, in said direction, and laterally spaced in said member, said elastic member and said cavities having a greater dimension in said direction along the roadway than said member is thick;

c. for each cavity a rigid bar positioned therein, each extending over a major portion of the length of the corresponding cavity and longitudinally movable relative thereto; and

d. a plurality of metal plates imbedded in said elastic member adjacent said end portions thereof, said plates including means, adjacent respective ends of said bars, for anchoring said elastic member to the roadway;

whereby said elastic member is elastically expandable and contractible over a considerable distance and is at the same time enabled by said bars to support considerable loads bearing down on said member.

2. The expansion joint according to claim 1 wherein the ends of said bars are rounded.

3. The expansion joint according to claim 1 wherein an upper surface of said member includes a plurality of grooves transverse of the roadway.

4. The expansion joint according to claim 1 wherein a lower surface of said member includes a plurality of grooves transverse of the roadway.

5. The expansion joint according to claim 1 wherein a lower surface of said member includes a plurality of grooves longitudinal of the roadway.

6. The expansion joint according to claim 1 wherein said anchoring means are directly attached to said metallic plates.

7. The expansion joint according to claim 1 wherein said member includes a substantially flat top surface and wherein said bars and cavities are parallel to said top surface.

8. The expansion joint according to claim 1 wherein said cavities are cylindrical.

9. The expansion joint according to claim 1 wherein said bars are of metal.