SHAFT WITH A BASE PLATE AND BASE PLATE FOR A PLASTIC SHAFT

Description

[0001] The invention relates to a shaft made of plastic, comprising shaft walls and a base plate. Up to now, the base plate – if one is provided in the shaft – is placed unsecured on the shaft floor and usually has a smooth or ribbed surface.

[0002] When work needs to be carried out on electrical / electronic components, cables, or devices housed within the shaft, a technician stands or kneels on the shaft floor to perform the necessary tasks. It is essential that the technician has a secure footing. This must be ensured even when the technician is in the shaft in adverse weather conditions and a wet environment, wearing dirty and / or slippery shoes. Furthermore, it is crucial that the base plate—if present—does not shift under any loads encountered during the technician's work.

[0003] From the applicant's prospectus "Plastic cable ducts | Underfloor distributors" dated June 1, 2018, cable ducts with duct walls and a square base plate are known, the upper surface of which has a multitude of internally hollow elevations distributed over its area and at least one recess at each of its edge areas, into which a foot section of a metal fastening tab is inserted, which is attached to the lower edge area of ​​the duct walls with fastening means.

[0004] DE 92 08 786 U1 discloses a cable duct made of plastic with a base plate which has a circumferential groove for inserting the duct walls and on each side a bracket projecting from the top with slots through which screws are inserted into the duct walls.

[0005] EP 3 258 757 A1 discloses a shaft in which the shaft walls are placed on edge profiles of a ribbed base plate.

[0006] In a shaft known from CN 109537633 A, the shaft walls are attached to a base plate by tabs and a bar.

[0007] The present invention aims to provide a base plate for a plastic shaft that is fixed immovably within the shaft and designed to provide a secure footing for a technician under all loads encountered. The base plate should be easy to install within the shaft.

[0008] This problem is solved according to the invention in a plastic shaft by the features of claim 1.

[0009] Advantageous embodiments of the invention are characterized in the dependent claims.

[0010] The invention provides that the base plate has a plurality of internally hollow protrusions distributed across its upper surface and at least one pocket-like recess at each of its edges, into which a foot section of a fastening tab is inserted or pushed, the fastening tab being attached to the lower edge of the shaft walls by fasteners. The plurality of protrusions evenly distributed across the surface of the base plate, preferably arranged in a checkerboard pattern, ensures a non-slip footing for a worker or technician in the shaft when working, for example, on electrical / electronic lines and equipment within the shaft. The upper surface of the protrusions may have small projections, such as raised lines, dots, etc., to further improve the anti-slip properties.Sufficient space remains between the elevations for the deposition of dirt or crusts of earth, which, in bad weather conditions, stick to the fitter's shoes and are carried into the shaft.

[0011] Furthermore, according to the invention, the base plate is fixed to the lower edge of the shaft walls with fastening means, for which purpose pocket-like recesses are provided in the edge regions of the base plate into which the foot sections of fastening tabs are inserted. In this way, the base plate according to the invention can be easily fastened to the lower edge of the shaft walls under the confined spatial conditions in the shaft.

[0012] In a preferred embodiment, the protrusions have a rectangular cuboid shape with rounded edges, which ensures that the shoes of a fitter cannot get caught on the protrusions or ridges.

[0013] According to the invention, the fastening tabs have an annular section connected to the base section via a central connecting section. The fastening tabs are made of plastic in one piece. The base section of the fastening tab has a wing-like shape, and the pocket-like recess has two separate pockets on both sides into which the wing-like base section is inserted. In this way, the fastening tab can be automatically inserted into the correct final position in the base plate, where its base section locks into place. The fastening tabs can thus also transmit vertical forces to the shaft walls if the base plate does not rest fully on the substrate, which can occur if the substrate is not concrete but consists of compacted soil.

[0014] It is strongly recommended that the ring-shaped section of the mounting tab be penetrated by a dowel, preferably made of plastic, which is driven into a pre-drilled hole in the shaft wall. This can be done quickly and easily by an installer.

[0015] Furthermore, it can be advantageously provided that at least one raised section is equipped with an inner dome to which internal components of the shaft can be attached using a self-tapping screw, preferably a plastic screw. Preferably, several such inner domes are provided on raised sections, each with a hole leading into the inner dome from its upper surface.

[0016] According to another essential aspect of the invention, the base plate is manufactured using injection molding, preferably from PC or PP.

[0017] Plastic manholes are manufactured in various rectangular shapes and sizes. To provide a cost-effective, suitable base plate for the commonly encountered designs, the invention provides that a base plate with the features described above has at least one size corresponding to the base area of ​​the largest manhole, and that smaller base plates are cut from the larger base plate. For this purpose, it is proposed that right-angled notches be formed on the edges of the largest base plate to act as stops for saw blades of varying thicknesses, with which the desired base plate can be cut to the respective dimensions. Since the base plate is preferably made of PC or PP, the excess base plate material generated during this process can be reused in the manufacturing process.

[0018] The invention thus provides a cost-effectively manufactured base plate for a shaft, which can be easily attached to the shaft walls and provides a secure, slip-free footing for a worker in the shaft.

[0019] Further details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The drawings show: Figure 1: A perspective view of a base plate; Figure 2: An enlarged view of a mounting tab with a dowel; Figure 3: A cut-out base plate with mounting tabs; Figure 4: Inserting the mounting tab into the base plate; Figure 5: Snapping the mounting tab into place; Figure 6: The foot section of a mounting tab with raised sections for snapping; Figure 7: A raised section with a screw point from above; Figure 8: The dome as a screw point from below; Figure 9: The extension of the base plate using a connector; Figure 10: Right-angled notches on the outer edges of the base plate; Figure 11: Attaching a base plate to the lower frame part of a plastic shaft; Figure 12: The foot section of a mounting tab inserted into pockets.

[0020] Figure 1Figure 1 shows a large base plate 1, manufactured from PC or PP by injection molding. The base plate contains numerous internally hollow protrusions 2, which have the shape of a rectangular cuboid with rounded edges. The protrusions are distributed in a checkerboard pattern over the entire surface of the base plate 1. Some protrusions 2a contain central holes that lead to an internal dome 3 ( Figure 8 ), into which self-tapping screws can be screwed to fasten shaft components. Other protrusions 2b have embossed logos on their upper surfaces to increase the slip resistance of the base plate 1. Contaminants carried on a technician's shoes can be deposited in the spaces between the protrusions 2.

[0021] Figure 2 shows a fastening tab 5, with the help of which a base plate 1 is attached to the lowest element 4 ( Figure 11) of a plastic cable duct. The mounting bracket 5 consists of an upper annular section 6, which is connected to a base section 8 via a central narrow connecting section 7, as shown in particular. Figure 6 The fastening tab 5 also contains reinforcing struts 9 and is made of plastic in one piece.

[0022] The foot section 8 contains a wing-like shape that extends at right angles to both sides from the central connecting section 7.

[0023] How Figure 4As shown, the base plate 1 contains a recess 10 in its edge region, which is slightly larger than the foot section 8, which can be inserted into this recess 10. The recess 10 continues into a central section 11, also open at the top, which is slightly wider than the central connecting section 7. To the right and left of this central section 11, pockets are formed in the base plate 1, which have the same overall width as the recess 10 and extend under the base plate 1, so that the foot section 8 can be inserted diagonally downwards into the open central area and into the two pockets covered above by the base plate. Figure 4 The insertion of the fastening tab 5 into the recess 10 is indicated by an arrow 12, while the arrow 13 points to Figure 5 Indicate the insertion of the fastening tab 5 into the pocket 14. Figure 12shows the foot section 8 inserted into the pockets 14 in a cutaway view that is greatly enlarged.

[0024] Figure 3 shows a base plate 1a, which is made from the large base plate 1 of the Figure 1 is cut out. At each of the four edge areas of the square base plate 1a, a fastening tab 5 is inserted into its final position, where it snaps into the pockets 14. The tabs 5 are secured with the aid of the Figure 2 The plastic dowel 15 shown is attached to the lower element 4 of a plastic cable duct, which is driven into a pre-drilled hole in the wall of the plastic duct using a hammer until the base 16 of the dowel rests against the annular section 6 of the fastening tab 5. The base plate 1 is inserted into a circumferential groove 22 ( Figure 11 ).

[0025] Figure 6shows that the foot section 8 has raised areas 15 on its upper side at both lateral end regions which snap into downward-pointing hook-shaped projections 16 on the base plate 1 when inserted into the pockets 14.

[0026] As mentioned above, some elevations 2a are provided with inner domes 3 into which a hole 17 in the top of the elevations 2a leads. Shaft components can be attached to these domes 3 by screwing self-tapping plastic screws into the domes. Figure 7 and 8 show a screw-in point from above and from below.

[0027] Figure 10 The figure shows in a greatly enlarged representation that right-angled notches 18 can be formed on the edges of the base plate, which serve as a stop for saw blades when the base plate is to be sawn to the respective dimension of the associated plastic shaft.

[0028] It may also be necessary to join two base plates together. Figure 9 shows that in this case recesses 19 are formed at the edge of the elevations 1, into which flat connecting elements 20 are inserted, which are fastened by means of a rivet 21 through a hole in the elevation 2.

Claims

1. A shaft with shaft walls and with a rectangular base plate (1), which has a plurality of internally hollow protuberances (2) on its upper surface distributed over its area and has at least one respective pocket-shaped opening at its edge regions, into which a respective foot section (8) on a fastening lug (5) is inserted, which is secured to the lower end region of the shaft walls (4) with fastening means (15), wherein the fastening lugs (5) each have an annular section (6), characterised in that the annular section (6) is connected by means of a central connecting section (7) to the foot section (8), which has a wing-like shape, and that the pocket-like opening (10) is somewhat larger than the foot section (8), wherein the opening (10) continues into an adjoining central section (11), which is also open at the top and which is somewhat wider than the central connecting section (7) and wherein formed in the base plate (1) to the right and left of the section (11) separated on both sides there are pockets (14), which overall have the same width as the opening (10) and which lead beneath the base plate (1) so that the foot section (8) may be slid into both pockets (14).

2. A shaft as claimed in Claim 1, characterised in that the protuberances (2) have a rectangular block shape with rounded edges.

3. A shaft as claimed in one of Claims 1 to 2, characterised in that the foot sections (8) of the fastening lugs (5) lock into the base plate (1) in the inserted end position.

4. A shaft as claimed in one of Claims 1 to 3, characterised in that a plastic peg (15), which is knocked into a hole in the shaft wall (4), passes through the annular section (6).

5. A shaft as claimed in one of Claims 1 to 4, characterised in that at least one protuberance (2a) is provided with an internal dome (3), to which fittings in the interior of the shaft may be fastened with the aid of a self-tapping plastic screw.

6. A shaft as claimed in one of Claims 1 to 5, characterised in that the base plate (1) is manufactured in an injection moulding process, preferably from PC or PP.

7. A shaft as claimed in one of Claims 1 to 6, characterised in that formed at the edges of the base plate (1) there are right angled notches (18) constituting a stop for saw blades of different thickness, with which the base plate (1) can be sawn to a desired size.