EP0449780A2 - Step element for moving walkway or escalator - Google Patents

Abstract

In order to achieve a secure connection between the edge strips (3) inserted in the tread plate (2) of a tread element and the tread plate (2), the edge strips (3) have a spring on their underside at least along their two longitudinal edges (6.7). The cross sections of the latter two have the shape of a parallelogram with mutually identical angles or a trapezoid and engage in the manner of a tongue and groove connection in corresponding grooves (8, 9) in the step plate (2). Furthermore, these edge strips (3) are also provided on their underside with at least two cast-on locking bolts (10) extending downwards and through the adjoining tread plate (2), each of which has a resilient spring on their free ends projecting downward from the tread plate (2) on the underside of the step plate 2 supporting clamping ring (11) is clamped.

Description

The invention relates to a step element for moving walk or stairs, with a step plate for receiving the people to be transported, this step plate being provided with an edge strip attached to it in the area of at least one of its longitudinal edges.

It is already known to provide tread elements with edge strips, either their attachment by means of a few screws to the tread element, seen over a longer period of use, which is sometimes not able to cope with the extremely harsh operating conditions and / or relatively complex mechanical processing of the tread elements produced in the die-casting process are required .

The object of the present invention is to provide a step element which does not have the disadvantages mentioned above and is extremely simple to assemble and simple Way allows a good fixation of the sidebar over its entire length.

This object is achieved according to the invention according to claim 1 or 2 in a tread element of the type mentioned.

To make the die-casting mold as simple as possible, it is advantageous if the tread element, including the grooves intended for receiving the edge strip springs and provided in the tread plate, is produced by the die-casting process, and that the direction of insertion of these grooves and preferably the longitudinal axis of the locking bolts and the associated passage openings in the tread plate runs parallel to the direction of extension of the tread element from the die casting mold during its manufacture. It is expedient if the direction of insertion of the grooves and tongues is at an angle of 25 to 50 °, preferably 38 °, with respect to a perpendicular to the step plate plane.

Appropriate further developments of the tread element according to the invention are the subject of claims 3 to 17.

The present invention also relates to an edge strip for a tread element according to one of claims 1 to 16.

• Fig.1 einen Grundriss einer beispielsweisen Ausführungsform eines für eine Fahrtreppe bestimmten erfindungsgemässen Trittelementes;
• Fig.2 eine Seitenansicht des in Figur 1 dargestellten Trittelementes;
• Fig.3 einen Schnitt längs der Linie III-III in Figur 1;
• Fig.4 eine Seitenansicht der in Figur 3 eingesetzten Randleiste;
• Fig. 5 eine Ansicht in Richtung des Pfeiles A in Figur 4 auf die Unterseite der Randleiste;
• Fig.6 eine Draufsicht auf die in den Figuren 4 und 5 dargestellte Randleiste;
• Fig.7 einen Schnitt längs der Linie VIII-VIII in Figur 1;
• Fig.8 einen Schnitt längs der Linie VIII-VIII in Figur 7;
• Fig.9 eine Draufsicht auf die in Figur 7 eingesetzte Randleiste;
• Fig.10 einer Unteransicht der in Figur 9 dargestellten Randleiste;
• Fig.11 eine Stirnansicht der Randleiste in Richtung des Pfeiles B in Figur 9 gesehen;
• Fig.12 einen Schnitt analog Fig. 8 durch eine weitere beispielsweise Ausführungsform einer seitlichen Randleiste mit schwalbenschwanzförmigen Federn;
• Fig.13 eine Untersicht der in Figur 11 dargestellten Randleiste;
• Fig.14 eine Seitenansicht analog Fig. 2 einer weiteren beispielsweisen Ausführungsform eines erfindungsgemässen Trittelementes;
• Fig.15 einen Schnitt längs der Linie XV-XV in Figur 14;
• Fig.16 einen Grundriss analog zu Figur 1 von einer weiteren beispielsweisen Ausführungsform eines erfindungsgemässen Trittelementes; und
• Fig.17 einen Schnitt längs der Linie VII-VII in Figur 16.
• Fig.18 einen Grundriss einer weiterenbeispielsweisen Ausführungsform eines für eine Fahrtreppe bestimmten erfindungsgemässen Trittelementes;
• Fig.19 eine Seitenansicht des in Figur 18 dargestellten Trittelementes;
• Fig.20 einen Schnitt längs der Linie XX-XX in Figur 18;
• Fig.21 eine Seitenansicht der in Figur 20 eingesetzten Randleiste;
• Fig.22 eine Ansicht in Richtung des Pfeiles A in Figur 21 auf die Unterseite der Randleiste;
• Fig.23 eine Draufsicht auf die in den Figuren 21 und 22 dargestellte Randleiste;
• Fig.24 einen Schnitt längs der Linie XXIV-XXIV in Figur 18;
• Fig.25 einen Schnitt längs der Linie XXV-XXV in Figur 24;
• Fig.26 eine Draufsicht auf die in Figur 24 eingesetzte Randleiste;
• Fig.27 einer Unteransicht der in Figur 26 dargestellten Randleiste;
• Fig.28 eine Stirnansicht der Randleiste in Richtung des Pfeiles B in Figur 26 gesehen;
• Fig.29 einen Schnitt längs der Linie XXIX-XXIX in Figur 27;
• Fig.30 eine Seitenansicht analog Fig. 19 einer weiteren beispielsweisen Ausführungsform eines erfindungsgemässen Trittelementes;
• Fig.31 einen Schnitt längs der Linie XXXI-XXXI in Figur 30;
• Fig.32 einen Grundriss analog zu Figur 18 von einer weiteren beispielsweisen Ausführungsform eines erfindungsgemässen Trittelementes; und
• Fig.33 einen Schnitt längs der Linie XXXIII-XXXIII in Figur 32.

The invention is explained below using the drawing, for example. It shows

• 1 shows a plan view of an exemplary embodiment of a tread element according to the invention intended for an escalator;
• 2 shows a side view of the tread element shown in FIG. 1;
• 3 shows a section along the line III-III in Figure 1;
• 4 shows a side view of the edge strip used in FIG. 3;
• 5 shows a view in the direction of arrow A in FIG. 4 onto the underside of the edge strip;
• 6 shows a plan view of the edge strip shown in FIGS. 4 and 5;
• 7 shows a section along the line VIII-VIII in Figure 1;
• 8 shows a section along the line VIII-VIII in Figure 7;
• 9 shows a plan view of the edge strip used in FIG. 7;
• 10 shows a bottom view of the edge strip shown in FIG. 9;
• 11 shows an end view of the edge strip in the direction of arrow B in FIG. 9;
• 12 shows a section analogous to FIG. 8 through a further exemplary embodiment of a lateral edge strip with dovetail-shaped springs;
• 13 shows a bottom view of the edge strip shown in FIG. 11;
• 14 shows a side view analogous to FIG. 2 of a further exemplary embodiment of a tread element according to the invention;
• 15 shows a section along the line XV-XV in Figure 14;
• 16 shows a plan similar to FIG. 1 of a further exemplary embodiment of a tread element according to the invention; and
• 17 shows a section along the line VII-VII in FIG. 16.
• 18 shows a plan view of a further exemplary embodiment of a tread element according to the invention intended for an escalator;
• 19 shows a side view of the tread element shown in FIG. 18;
• 20 shows a section along the line XX-XX in FIG. 18;
• 21 shows a side view of the edge strip used in FIG. 20;
• 22 shows a view in the direction of arrow A in FIG. 21 onto the underside of the edge strip;
• 23 shows a plan view of the edge strip shown in FIGS. 21 and 22;
• 24 shows a section along the line XXIV-XXIV in FIG. 18;
• 25 shows a section along the line XXV-XXV in FIG. 24;
• 26 shows a plan view of the edge strip used in FIG. 24;
• 27 shows a bottom view of the edge strip shown in FIG. 26;
• 28 shows an end view of the edge strip in the direction of arrow B in FIG. 26;
• 29 shows a section along the line XXIX-XXIX in FIG. 27;
• 30 shows a side view analogous to FIG. 19 of a further exemplary embodiment of a tread element according to the invention;
• 31 shows a section along the line XXXI-XXXI in FIG. 30;
• 32 shows a floor plan analogous to FIG. 18 of a further exemplary embodiment of a tread element according to the invention; and
• 33 shows a section along the line XXXIII-XXXIII in FIG. 32.

As can be seen from FIGS. 1 and 2, the tread element 1 (hereinafter called escalator step) of an escalator is provided with a tread plate 2 for receiving the person to be transported. The tread plate 2 has edge strips 3, 4 and 5 inserted into it and fastened to it.

As can be seen from FIGS. 3, 4 and 5, the rear edge strip 3 has a spring 6 and 7 on its underside along its two longitudinal edges, the cross sections of which have the shape of a parallelogram with angles identical to one another, and in the manner of a Engage the tongue and groove connection in the corresponding grooves 8 and 9 in the tread plate 2.

This rear edge strip 3 furthermore has on its underside two guide and locking bolts 10, which are distributed over its length, downwards and through and through the adjoining tread plate 2, which form a piece with the edge strip 3, and at the edge of which Step plate 2 protruding downward free ends each a clamping ring 11 which is supported under spring pressure on the underside of the step plate 2 is clamped.

The tread element 1, including the grooves 8 and 9 provided in the tread plate 2 for receiving the edge strip springs 6 and 7, is produced by the die-casting process, the direction of insertion of these springs 6, 7 and grooves 8, 9 and the longitudinal axis of the guide and locking bolts 10 and the associated guide and passage openings 12 in the tread plate 2 run parallel to the extension direction Z of the tread element 1 from the die casting mold during its manufacture, so that the simplest possible die casting die can be produced. In the exemplary embodiment shown, this extension direction Z runs at an angle α of 38 ° with respect to a perpendicular to the step plate plane 13.

The edge strip 3 is provided with the same rib division as the tread plate 2, with mutual locking the ribs 14 of the edge strip 3 with the ribs 15 of the tread plate 2, part of the ribs 14 of the edge strip 3 are provided on their sides adjacent to the ribs 15 of the tread plate 2 with guide grooves 16, into each of which a front-arranged guide ridge 17 of the adjacent ribs of the Step plate 2 engages. To insert the guide combs 17 into the associated guide grooves 16, the latter are open on their lower end faces 18.

As can be seen from FIGS. 7 to 11, the two lateral edge strips 4 and 5 are provided on their underside with a plurality of springs 19 which are distributed over their length and extend in their transverse direction, the cross sections of which are analogous to the springs 6 and 7 of the rear edge strip 3 have the shape of a parallelogram with mutually identical angles and engage in corresponding grooves 20 in the step plate 2 in the manner of a tongue and groove connection. These two side edge strips 4 and 5 are, similarly to the rear edge strip 3, also provided on their underside on their underside with two guide and locking bolts 10, which are distributed over their length and extend downwards and through the adjoining tread plate 2, at the bottom thereof from the tread plate 2 protruding free ends analogous to the rear edge strip 3, a clamping ring 11 which is supported under spring pressure on the underside of the step plate 2 is clamped.

The guide and locking bolts 10, the guide and passage openings 12 assigned to them and the tongue and groove connections 19, 20 are coordinated with one another analogously to the rear edge strip 3 in such a way that they unimpeded retraction of the springs 19 of the two edge strips 4 and 5 in allow the grooves 20 associated with these springs 19 in the tread plate 2.

The insertion direction Z of the tongue and groove connection 19, 20 and the guide and locking bolt 10 is the same as for the rear edge strip 3 already described above for the simplest possible production.

Since the support surfaces 21 and the grooves 8 and 9 and 20, respectively, determined in the tread plate 2 for the edge strips 3, 4 and 5, and the grooves 8 and 9 and 20 respectively, and the guide and passage openings 12 during the production of the tread element 1 in the die-casting mold, all from above, That means that they can be produced from a single side of the die-casting mold, these edge strip anchoring grooves 8, 9 and 20 can be so precisely produced in the die-casting process with respect to the edge strip contact surfaces 21 and the guide openings 12 that the edge strips 3 are held practically without play (without clamping rings 11) , 4 and 5 in the tread plate 2 any mechanical reworking of the tread elements 1 designed in this way is superfluous, which represents a huge advantage in terms of production.

The installation of these edge strips 3, 4 and 5 is extremely simple, since they are simply inserted obliquely into the tread plate 2 and then the clamping rings 11 onto the free ends of the guide and locking bolts inserted into the tread plate 2 that protrude from the underside of the tread plate 2 10 can be pressed.

The clamping rings 11 are made of spring steel and are shaped so that they can be pressed onto the slightly conical locking bolts 10 in a simple manner up to the resilient contact on the underside of the tread plate 2 and then there automatically on the latter clamp. Slightly cambered spring washers or disc springs as well as so-called Schnorr rib washers can also be used as clamping rings 11.

In order to be able to easily replace such an attached edge strip 3, 4 or 5 in the event of any damage during operation, e.g. 11 can be seen in the longitudinal axis of the guide and locking bolts 10 on the top of the edge strips 3, 4 and 5 and on the downward free end face of the guide and locking bolts 10 centering countersinks 22 and 23 for centering a drill for drilling out the relevant guide - And locking bolt 10 are provided so that the latter can be eliminated in a simple manner and the defective edge strips can be removed without the subsequent attachment of a new edge strip causing any additional problems.

For additional lateral anchoring of the front end faces 24 of the ribs 25 of the two lateral edge strips 4 and 5, these are also provided, analogously to the rear edge strip 3, with guide grooves 16, in each of which a guide comb 17 of the escalator step 1 engages (FIG. 7).

In the embodiment shown in FIGS. 12 and 13, in contrast to the embodiment shown in FIGS. 7 to 11, the grooves 19 'and the springs 20' are provided with a dovetail cross section.

Such edge strips 4 ', 5' can be pushed into each other because of the shape of the grooves 19 'and the springs 19' only in the lateral direction of these edge strips 4 ', 5'. In order to enable such a lateral insertion, the in the Step plate 2 'for the locking bolt 10' provided through openings 12 'be open laterally in the form of a slot.

As can be seen from FIGS. 14 and 15, it is also possible to have the two lateral edge strips 4 and 5 on their longitudinal edge, which is directed outward with respect to the tread plate 2, with a first side skirt that extends downward and forms a piece with the edge strip 4 and 5, respectively 26, and the arch-shaped front wall 27 (see FIG. 14) of the step element 1 with two lateral side skirts 28 which extend from the front wall 27 to the rear. The common dividing line 29 between the partially abutting respective two side skirts 26 and 28 runs at the same or a larger angle α than the insertion direction Z of the tongue and groove connection 19, 20. Analogously to the ribs 14 and 25 of the edge strips 3, 4 and 5, the side skirts 26 of the edge strips 5˝ or 4˝ (not shown) are provided with a guide groove 16˝ in their area adjacent to the associated side skirt 28, into which a guide comb 17˝ of the associated side skirt 28 is provided for mutual lateral fixing and centering of the tread element 1 engages.

Normally, the escalator steps consist of a magnesium alloy and the edge strips 3, 4 and 5 together with the locking bolts 10 provided on them from weatherproof, impact-resistant and aging-resistant plastic.

In the embodiment shown in FIGS. 16 and 17, the edge strips 3, 4 and 5 are formed by inserting into the step plate 2 and distancing it from the outside of the latter. signaling strips of a different color forming part of the tread surface of the tread plate 2, the plastic from which these edge strips consist is colored, for example, with a yellow glow.

The rear edge strip 3 has, for the lateral centering of its ribs 14 with respect to the ribs 15 of the tread plate 2 on both end faces of its ribs 14, guide grooves 16 into which guide ridges 17 of the abutting end faces of the ribs 15 of the tread plate 2 engage. Here too, the guide grooves 16 for inserting the guide combs 17 are open at their lower end 18.

Of course, it is also possible to provide the step plate 2 with edge strips on all four sides, the front edge strip being able to be fastened in the step plate 2 analogously to the rear edge strip 3.

Parts analogous to FIGS. 1 to 17 are given the same reference symbols in FIGS. 18 to 33 below, so that a detailed description of the same parts is unnecessary and only the different features are described.

In contrast to the previously described Asführungsformen the rear edge strip 3, as can be seen from Figures 20, 21 and 22, on its underside along its two longitudinal edges each have a spring 6 or 7, the cross sections of which are identical in shape to a trapezoid Have angles, and engage in the manner of a tongue and groove connection in corresponding grooves 8 and 9 in the step plate 2.

In the embodiment of the interlocking springs 6, 7 and grooves 8, 9 shown in FIGS. 18 to 30, the extension direction Z or the angle δ between the longitudinal axis 10 'of the guide and locking bolts 10 and a perpendicular to the step plate plane 13 can also be smaller than be the angle α.

In order to relieve the guide and locking bolts 10 on in the longitudinal direction of the front edge strip 3 or in the longitudinal direction of the tongue and groove connections 6,7; 8.9 to achieve forces P acting on this edge strip 3 are centering and relief projections on the underside of these edge strips 3, preferably in the area of the guide and locking bolts 10, transverse to the longitudinal direction of the springs 6, 7, having an approximately triangular cross section or ribs 30 (see FIG. 22) are provided, which engage in a form-locking manner in associated centering and relief grooves 31 provided in the step plate 2. The guide and locking bolts 10 in turn also preferably engage in a form-locking manner without play in the associated guide and passage openings 12 provided in the step plate 2.

As can be seen from FIGS. 24 to 28, the two lateral edge strips 4 and 5 are provided on their underside with a plurality of springs 19, which are distributed over their length and extend in their transverse direction, the cross sections of which are analogous to the springs 6 and 7 of the rear Edge strip 3 have the shape of a trapezoid with mutually identical angles and, as in the exemplary embodiments described with reference to FIGS. 1 to 17, engage in corresponding grooves 20 in the step plate 2 in the manner of a tongue and groove connection.

In order to relieve the load on the guide and locking bolts 10 and on lateral evasion of these side edge strips 4, 5 in their area between the guide and locking bolts 10 with the transverse to the longitudinal direction of the side edge strips 4, 5 or in the longitudinal direction of the tongue and groove connections 19, To achieve 20 forces Q acting on these edge strips 4.5 are on the underside of these edge strips 4.5 in the region of the guide and locking bolts 10 and in the region between them, distributed over the entire length of these edge strips 4.5, transversely to the longitudinal direction the tongue and groove connections 19, 20 and centering and relief projections or ribs 30 (see FIGS. 25, 28 and 29), which run approximately at a triangular cross-section and run transversely to the longitudinal direction of these edge strips 4.5, which are positively locking in assigned in the centering and relief grooves 31 provided on the tread plate 2 engage. In the case of these side edge strips 4, 5, too, the guide and locking bolts 10 engage, preferably also in a form-locking manner, without play in the associated guide and passage openings 12 provided in the step plate 2.

As can be seen from FIGS. 30 and 31, it is also possible here for the two lateral edge strips 4 and 5 on their longitudinal edge, which is directed outwards with respect to the tread plate 2, with a first extending downward and forming a piece with the edge strip 4 and 5, respectively To form the side skirt 26 and the curved front wall 27 (see FIG. 13) of the tread element 1 with two lateral side skirts 28 which extend rearward from the front wall 27.

Normally, the escalator steps consist of a magnesium alloy and the edge strips 3, 4 and 5 together with the locking bolts 10 provided on them from weatherproof, impact-resistant and aging-resistant plastic.

In the embodiment shown in FIGS. 32 and 33, the edge strips 3, 4 and 5 are formed by signaling strips of a different color, which are inserted into the step plate 2 and distanced from the outside of the latter and form part of the step surface of the step plate 2, the plastic from which forms these edge strips exist, for example, colored bright yellow.

The rear edge strip 3 has, in addition to the centering and relief projections 30 for the lateral centering of its ribs 14 with respect to the ribs 15 of the tread plate 2 on both end faces of its ribs 14, additional guide grooves 16 into which guide ridges 17 of the abutting end faces of the ribs 15 of the tread plate 2 engage . Here too, the guide grooves 16 for inserting the guide combs 17 are open at their lower end 18.

The springs 6, 7 and the associated grooves 8, 9 have parallelogram-shaped cross sections for an even better anchoring of the edge strips in the step plate 2.

Claims (18)

Step element for moving walk or stairs, with a step plate for receiving the people to be transported, this step plate being provided in the area of at least one of its longitudinal edges with an edge strip attached to it, characterized in that the at least one edge strip (3) on its underside at least along its two longitudinal edges is provided with a spring (6, 7), the cross sections of which have the shape of a parallelogram with mutually identical angles, two of which are at least 110 °, or at least approximately the shape of a trapezoid, and in which Type of a tongue and groove connection engage in corresponding grooves (8, 9) in the tread plate (2), and that this edge strip (3) on its underside also has at least two downward and through the adjacent tread plate (2 ) extending locking bolts (10), freely projecting downwards from the tread plate (2) Each ends of a clamping ring that is supported on the tread plate (2) under spring pressure (11) is clamped, these locking bolts (10) and the passage openings (12) assigned to them in the tread plate (2) being matched to one another such that they allow the springs (6, 7) of the edge strip (3) to move freely into the allow them assigned grooves (8,9) in the tread plate (2). Step element for moving walk or stairs, with a step plate for receiving the people to be transported, this step plate being provided in the area of at least one of its longitudinal edges with an edge strip attached to it, characterized in that the at least one edge strip (4, 5) is attached to it The underside is provided with a plurality of springs (19) distributed over its length and extending in its transverse direction, the cross-sections of which have the shape of a parallelogram with mutually identical angles, two of which are parallel to each parallelogram or at least approximately the shape of one Have trapezes, and engage in the manner of a tongue and groove connection in corresponding grooves (20) in the tread plate (2), and that this edge strip (4, 5) on its underside is also arranged at least two downwards over its length and has locking bolts (10) extending through the adjacent tread plate, a n whose free ends projecting downward from the tread plate, a clamping ring (11), which is supported under spring pressure on the tread plate (2), is clamped, these locking bolts (10) and the passage openings (12) assigned to them in the tread plate (2) in such a way are coordinated with one another so that they allow the springs (19) of the edge strip (4, 5) to move freely into the grooves (20) assigned to them in the tread plate (2). Tread element according to claim 1 or 2, characterized in that the base lines of the at least approximately trapezoidal cross-sections of the springs (6, 7) run at least approximately parallel to the plane of the tread plate, that of the mutually analogous angles of the springs (6, 7) one of the tread plate away angle (β) at least 110 °, the other angle (γ) facing away from the tread plate is at most 90 ° and the sum of these two angles (β, γ) is at least 180 °. Tread element according to one of claims 1 to 3, characterized in that the at least one edge strip (3, 4, 5) on its underside with at least one, preferably at least one, transverse, preferably perpendicular, to the springs (6, 7, 19) is provided with an approximately triangular cross-section centering projection which, in the longitudinal direction of the springs (6, 7, 19), engages in a form-fitting manner with a centering action in the associated centering recess (31) provided in the step plate (2). Step element according to claim 4, characterized in that the centering projections and recesses (30, 31) are arranged as shown in Figures 1 to 16. Tread element according to claim 1 or 2, characterized in that the tread element (1), including the grooves (8, 9; 20) provided in the tread plate (2) for receiving the edge strip springs (6, 7; 19), is produced by the die casting process , and that the direction of insertion of these grooves (8,9; 20) and preferably the longitudinal axis of the locking bolts (10) and the associated Passage openings (12) in the tread plate (2) run parallel to the extension direction (Z) of the tread element (1) from the die casting mold during its manufacture. Tread element according to claim 6, characterized in that the insertion direction (Z) of the grooves (8,9; 20) and springs (6,7; 19) at an angle (α) of 25 to 50 °, preferably 38 °, with respect to one Vertical to the step plate level (13) runs. Step element according to one of Claims 1 to 7, characterized in that the step plate (2) is provided with the edge strip on at least one of its outer edges (Fig. 1). Tread element according to one of Claims 1 to 7, characterized in that the edge strip (3, 4, 5) forms part of the tread surface of the tread plate (2) by at least one inserted into the tread plate (2) and distanced from the outside of the latter different colored signaling strips is formed (Fig. 16). Tread element according to one of claims 1 to 9, characterized in that the edge strip (3, 4, 5) is provided with the same rib division as the tread plate (2), and that at least part of the ribs (14, 25) of the edge strip ( 3, 4, 5) are provided on their sides adjacent to the ribs (15, 15 ') of the tread plate (2) with guide grooves (16) into which a guide comb (17) of the adjacent ribs (15, 15') is arranged. ) engages the tread plate (2), the guide grooves (16) for introducing the associated guide combs (17) on their lower end faces (18) being open. Tread element according to one of claims 1 to 10, characterized in that in the longitudinal axis of the respective locking bolt (10) on the top of the edge strips (3, 4, 5) and / or on the downward face of the individual locking bolts (10) each a centering counterbore (22, 23) is provided for centering a drill for drilling out and removing the locking bolt (10) in question. Tread element according to claim 1 or 2, characterized in that the locking bolts (10) run at least approximately perpendicular to the level of the tread plate, and that the passage openings (12) associated with these locking bolts (10) and preferably also the locking bolts are widened as seen in the extension direction. Step element according to one of claims 1 to 12, characterized in that the two lateral edge strips (4, 5) on their longitudinal edge which is directed outwards with respect to the step plate (2) with a downwardly extending first side skirt (26) and the curved front wall ( 27) of the tread element (1) are provided with two lateral side skirts (28) which extend backwards from the front wall (27) so that the common dividing line (29) between the partially abutting respective two side skirts (26, 28) underneath the same or greater angle (α) than the direction of insertion (Z) of the tongue and groove connection (19, 20), and that the first side skirts (26) in their area adjacent to the assigned second side skirt (28) each have a guide groove ( 16˝) are provided, in which a guide comb (17˝) of the assigned second side skirt (28) engages. Tread element according to claim 2, characterized in that the grooves (20 ′) and the springs (19 ′) have a dovetail cross-section (FIGS. 12 and 13). Tread element according to claim 1 or 2, characterized in that the locking bolts (10) are designed as guide bolts and preferably extend without play through the assigned passage openings (12) in the tread plate (2), provided a sliding seat is provided. Step element according to one of claims 1 to 15, characterized in that the locking bolts (10) are slightly conical and the inner diameter of the clamping rings (12) made of spring steel, which is slightly cambered in the relaxed state, are dimensioned such that they are non-positive system on the underside of the tread plate (2) in clamping engagement with the assigned locking bolt (10). Step element according to one of Claims 1 to 16, characterized in that the locking bolts (10) consist of one piece with the edge strip (3, 4, 5) and these parts are preferably made of weatherproof, aging-resistant and impact-resistant plastic. Edge strip for a tread element according to one of claims 1 to 17.

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