Fastener

Abstract

Fastening element (1) for the mechanical fastening of insulating materials and sealing membranes on flat roofs, wherein the fastening element (1) consists of a plastic sleeve (2) with a coaxial inner channel (4) forming a hollow shaft (3), into which a countersunk screw (5) can be inserted, the screw head of which rests on a bearing shoulder formed therein within the hollow shaft (3) near the shaft tip (6) and the screw shaft of which protrudes from the shaft tip of the plastic sleeve (2) and consists of a head plate (7, 7a, 7b) adaptable to the plastic sleeve (2), and wherein the head plate (7, 7a, 7b) is made of plastic and has a metallic insert (15), characterized in that the metallic insert (15) is embedded in the head plate (7b) near the underside (13) of the plate and has projections (17) extending beyond the underside (13) of the plate.

Description

[0001] The invention relates to a fastening element for the mechanical fastening of insulation materials and sealing membranes on flat roofs according to the preamble of claim 1.

[0002] Various fastening systems are used for the mechanical fastening of insulation materials and waterproofing membranes on flat roofs. A fundamental distinction is made between perimeter, linear, and field fastening. With perimeter fastening, the roofing membranes are pierced by fasteners in the perimeter area, after which the screw cuts into the roof substrate, e.g., a trapezoidal steel sheet. The insulation material and the waterproofing membrane are then clamped between the trapezoidal steel sheet and the end plate or washer, thus mechanically fastening them. The row of fasteners along the perimeter is covered by the next parallel roofing membrane, and the overlap area is welded. Typically, so-called plastic screw combinations are used for this purpose, as described in DE 43 19 054 C2, DE 10034126 A1, DE 3717429 A1, and DE 20 2006 019 303 U1.These are fasteners, each consisting of a plastic holder and a screw. The plastic holder has a round or oval load-distributing head plate, below which extends a hollow shaft with a coaxial inner channel for receiving the screw. The screw head rests inside the hollow shaft near the shaft tip on a bearing shoulder formed there, and the screw shaft protrudes from the shaft tip of the plastic holder.

[0003] Linear fastening utilizes a slotted rail, which acts as the end plate. According to DE 10 2005 017 921 A1, a plastic sleeve with a collar is used, essentially corresponding to the plastic holder of a plastic screw assembly, into which a screw is also inserted. The collar rests on the top edge of the rail, while the screw is countersunk within the sleeve and cuts into the roof substrate. The fastening rail is covered and sealed with a strip of foil. The rails are spaced relatively far apart, necessitating additional fastening of the insulation material. For this purpose, a plastic screw assembly, consisting of a plastic holder with an end plate and a screw, is used, as described for perimeter fastening.

[0004] In field fastening, the roofing membrane is not fixed at the seam, but rather pierced across its surface by the fastener used, and the fastening point is then sealed. Various field fastening systems are known, for example, from US 4,787,188 A, in which the head plate also serves as the sealing washer. DE 10 2005 011 188 A1 describes an improved field fastening system. This system uses a plastic screw combination, as known from DE 43 19 054 C2. After the fastener is set, a sealing washer is placed on the head plate, and the head plate is then welded to the roofing membrane.

[0005] If linear fastening is chosen for mechanical roof fixing, the installer may, in the worst-case scenario, require three different fasteners from three different manufacturers. This, in turn, leads to a multitude of different, non-uniformly usable processing devices, so-called setting machines, since different end plate shapes cannot be processed in one and the same machine.

[0006] German patent DE 199 59 270 A1 describes a slip-resistant fastening element consisting of a sleeve-shaped plastic shaft with a countersunk screw and a separate metal head plate. The head plate is slid onto the sleeve from the shaft tip and rests on a partially open ring below the sleeve head. The head plate is first slid over this ring and locked in place by turning. This type of fastening element is ideally suited for applications involving open flame welding of roofing sheets, as the metal head plate is resistant to accidental prolonged exposure to the flame. However, the use of this combined plastic sleeve with metal head plate is limited to this specific application, as the sleeve and head plate are precisely matched and cannot be used with other components or for other applications.

[0007] A fastening element with a separate head plate is also described in DE 10 2005 018 178 A1. This design features a sleeve with an internal thread or grid onto which a head plate with a central pin, having an external thread or grid, is mounted. This length-variable fastening element is intended to secure different insulation thicknesses with a single fastener. US 4,686,808 A describes a fastening element consisting solely of a load-distributing plate and a screw, but without a plastic sleeve to house the screw. The load-distributing plate contains a smooth metal insert completely encased in plastic and has no protrusions extending from its underside.

[0008] A review of the current state of the art reveals the persistent problem that users must employ various systems for the mechanical fastening of roof structures on flat roofs. Furthermore, the equipment of one manufacturer is often incompatible with fasteners from another manufacturer, severely limiting the installer's material options.

[0009] The present invention aims to create a way to minimize both the large number of different fastening elements and thus also the storage requirements, as well as the wide range of processing equipment.

[0010] This problem is solved according to the invention by a head plate having the features of claim 1.

[0011] According to the invention, a fastening element for the mechanical fastening of insulation materials and sealing membranes on flat roofs is proposed, wherein the fastening element consists of a plastic sleeve with a coaxial inner channel forming a hollow shaft, in which a countersunk screw is inserted, the screw head of which rests on a bearing shoulder formed therein within the hollow shaft near the shaft tip and the screw shaft of which protrudes from the shaft tip of the plastic sleeve, and a head plate adaptable to the plastic sleeve, wherein the head plate is made of plastic and has a metallic insert which is embedded near the underside in the head plate and has a projection extending beyond the underside of the plate.

[0012] The invention allows for the combination of various plastic sleeves and different head plates for a wide range of applications, thus creating customized fastening elements. On a flat roof where linear fastening is used, the plastic sleeve with screw is used alone for rail fastening. The same type of plastic sleeve is adapted with a suitable head plate and used for fastening insulation between the rails. If edge and corner fastening using surface fasteners is employed, the fastening element fitted with the head plate can be used and sealed with the compatible sealing plate. Furthermore, if the installer only has a setting tool that can only process fasteners with, for example, an oval head plate, the sleeve can be adapted with such a head plate.

[0013] It is also possible, for example, to use head plates with different colors, which may be required for a variety of reasons. The invention also allows for combinations with head plates of technically complex designs. The injection molding process for a single plate proves to be simpler from a tooling perspective than the production of a complete fastener with shank and head plate. Therefore, a head plate with a complex design, such as one with an inlay, can be manufactured more easily and thus more cost-effectively than a single-piece element with this feature.

[0014] A particularly preferred embodiment of the invention provides that the collar of the plastic sleeve is designed as a circular cylindrical ring. As a counterpart, the recess of the head plate is designed as a circular cylindrical chamber. In a corresponding embodiment with a positive / negative part, the collar is positioned in the head plate such that it is flush with the top surface of the head plate. The fully assembled fastening element then corresponds in appearance and dimensions to a one-piece fastening element.

[0015] Another preferred embodiment of the invention provides that a locking element is formed between the head plate and the plastic sleeve. Particularly when this is designed as a clip connection, the adaptation of the parts to one another is extremely simple and efficient.

[0016] A particularly preferred embodiment of the invention provides that a circumferential groove is arranged below the collar of the plastic sleeve, cutting into the shaft and corresponding to a circular cylindrical ring located in the recess. When the head plate is pushed onto the plastic sleeve from the tip of its shaft, the ring comes to rest in the groove, producing a distinct snapping sound. This assures the user that the connection between the two parts has been made correctly.

[0017] In a further embodiment of the invention, the head plate is provided with pins, teeth, or hooks on its underside, which are arranged on the metal insert and project sufficiently from under the underside of the head plate and interlock with the roofing membrane. This allows for increased resistance in conjunction with the underlying roofing membrane.

[0018] Further advantages and advantageous embodiments of the invention can be found in the following description, the drawing and the claims.

[0019] There are various ways to advantageously develop and refine the teaching of the present invention. Reference is made, on the one hand, to the dependent claims and, on the other hand, to the following explanation of an exemplary embodiment of the invention with reference to the drawing. In conjunction with the explanation of the preferred embodiment of the invention with reference to the drawing, generally preferred embodiments and further developments of the teaching are also explained.

[0020] The invention will be described in more detail below with reference to the drawing.

[0021] This shows: Fig. 1 a screw Fig. 2 a plastic sleeve Fig. 3 a headplate Fig. 4. an enlargement of the plastic sleeve in the area of ​​the collar Fig. 5 an enlargement of the head plate in cross-section Fig. 6 a head plate with pins arranged on the underside Fig. 7 a headstock with inlay

[0022] The Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. Figure 5 shows individual elements that are used in connection with the head plate according to the invention.

[0023] The fastening element, designated as a whole by 1, consists of a plastic sleeve 2, a screw 5, and a plastic head plate 7. The plastic sleeve 2 has a hollow shaft 3 with an inner channel 4 into which the screw 5 is inserted, so that the screw head is countersunk within the sleeve, while the other end of the screw 5 protrudes from the shaft tip 6. At the end of the plastic sleeve 2 opposite the shaft tip 6, it has a collar 8. The collar is designed as a circular cylindrical ring and has a larger diameter than the hollow shaft 3. This collar 8 allows the plastic sleeve 2 to rest in the recess 9 of the head plate 7 after it has been slid onto the hollow shaft 3 from the shaft tip 6. For this purpose, a shoulder 16 is formed in the recess 9, on which the collar 8 rests. A circumferential groove 11 is provided on the plastic sleeve 2 directly below the collar 8.This groove 11 corresponds to a circular cylindrical ring 12 within the recess 9 of the head plate 7. When the head plate and plastic sleeve are brought together, both parts clip into each other by the ring snapping into the groove, which can be heard as a slight cracking sound.

[0024] The Fig. Figure 6 shows a head plate 7a not covered by the claims, which has 13 raised pins 14 on its underside that grip into the underlying roofing membrane.

[0025] Fig. Figure 7 shows the embodiment of the head plate 7b according to the invention, which has an insert 15. The insert 15 is embedded in the head plate 7b near the underside 13 of the plate, wherein the insert 15 has projections 17 that extend downwards beyond the underside 13 of the plate. Reference symbol list 1 fastening element 2 plastic sleeves 3 Hollow shaft 4 inner channel 5 screws 6 shaft tip 7 Headplate 8 collars 9 trough 10 Top edge of head plate 11 groove 12 Ring 13 Underside of headplate 14 pencils 15 deposit Paragraph 16 17 surveys

Claims

[1] Fastening element (1) for the mechanical fastening of insulation materials and sealing membranes on flat roofs, wherein the fastening element (1) consists of a plastic sleeve (2) with a coaxial inner channel (4) forming a hollow shaft (3) into which a countersunk screw (5) can be inserted, the screw head of which rests on a bearing shoulder formed therein within the hollow shaft (3) near the shaft tip (6) and the screw shaft of which protrudes from the shaft tip of the plastic sleeve (2) and consists of a head plate (7, 7a, 7b) adaptable to the plastic sleeve (2), and wherein the head plate (7, 7a, 7b) is made of plastic and has a metallic insert (15), characterized by , that the metallic insert (15) is embedded near the underside of the plate (13) in the head plate (7b) and has protrusions (17) extending beyond the underside of the plate (13). [2] Fastening element according to claim 1, characterized by, that a depression (9) is formed in the head plate (7, 7a, 7b). [3] Fastening element according to claim 2, characterized by , that the depression (9) of the head plate (7, 7a, 7b) is designed as a circular cylindrical chamber. [4] Fastening element according to one of claims 2 or 3, characterized by , that in the hollow (9) a circular cylindrical ring (12) raised from the hollow wall is formed. [5] Fastening element according to any one of claims 2 to 4, characterized by , that a step (16) is formed in the hollow (9). [6] Fastening element according to any of the preceding claims, characterized by , that the head plate (7a) has pins (14), teeth or hooks on its underside (13).

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