Patent GB-973879-A (GB)
Title: Joint seal of the grating-bar type for roads and footpaths
IPC: E01C11/12
Filed: 1962-07-05
Abstract: 973,879. Expansion joints. RHEINSTAHL UNION BRUCKENBAU A.G. July 5, 1962 [July 6, 1961], No. 25811/62. Heading E1G. A joint seal of the grating bar type for expansion joints between structure parts of roads or footpaths consists of grating bars with resilient pads therebetween, the width of the seal in the relaxed state being greater than the maximum expanded width of the joint, and means to compress the seal to a width less than the minimum width of the joint, which is releasable when the seal is in position in the joint for the seal to expand and exert pressure on the joint walls. In one form shown (Fig. 1) there are elastic sealing pads 1, an I-section grating-bar 2, and channel girders 3, which are pressed against the structure parts 5 and 15, as a result of prestressing by a bolt 4, when nuts 14 are relaxed through a recess 6 in the part 5 after the seal is inserted in the joint. The bolt 4 can then be removed by means of the recess 16 in the part 15, after which the recesses 6, and 16 are filled with, e.g. concrete, a concrete slab 8 being below the joint on which is a sliding layer 9. The grating bars may be of the lattice-type with upper booms 11 (Fig. 2) having their upper and lower edges at the heights shown and the spaces may be filled by pads 13 of synthetic plastics material, flat plates being at the edges. Fig. 4 shows a modification of Fig. 2 in which spindle presses 20 are used for pre-stressing in recesses 21 after which the space 22 is partly filled with concrete which is allowed to set before removal of the presses 20 and complete filling. In a form similar to that of Fig. 1 after the fitting of the joint the nuts 14 are removed from bolts 4 by a recess in the part 5 and the bolts are left in, the seal comprising flat plates and intervening pads. In Fig. 6 are shown tie rods 25 which extend transversely with wedges 26 in slots therein and are used for prestressing, the wedges being removed after insertion of the seal in the joint. Fig. 7 shows a seal cross-section with no bolts 4, as in Fig. 1, but a clamping bolt 7 arranged over the length of the seal and holding it together, although in three parts, to prestress it in a known manner. Two expansion units 32 against which bears an intervening girder 33 (Fig. 10), may rest on a bearing beam 30 (on beams 38) movable in the direction of expansion of the seal and of extended width equal to the road-contact length of a vehicle wheel. The girder 33 is hollow and the structure parts 5, 15 carry an end facing 31, the pads 35 and bars 34 being as shown in Fig. 14, the outermost bar 34 being welded at 44 to the facing 31. To move the beam 39 (Fig. 10) the girder 33 is fixed thereon by means of a bolt 41 and each unit 32 has at least two guide rods 50. The bolt 41 forms a pivot 41a (Fig. 11) for a linkage 42 held in the plates 40 by means of pivot pins 42a and rods 43 and on expanding the parts 5 and 15, the linkage 42 so moves the beam 39 that the girder 33 is always in the middle of the joint 37. Such a position is obtained in a modification without the use of such guiding means. In two further modifications of the form of Fig. 10 the spaces between the girder and the parts 5, 15 are made narrower above than below, so that after introduction into the joint the units are wedged therein. In the form shown in Figs. 16 and 18 there are three expansion joints 32 with two intervening girders 33 supported on two bearing beams 39 connected by pivots 41b formed by bolts 47 and staggered in location when the joint is unexpanded, the girders 33 being each fixed only to one particular beam 39, and there are two guide rods 50 as shown in Fig. 10. Wire ropes may be arranged parallel to the bars, preferably in tubes. Divisions between units and between intermediate girders may be longitudinally offset relatively to one another.