Patent Application
20230213054
The present invention relates in general to a gradient insulation screw, a system of gradient insulation screw and holding element, as well as a method for adjustable fastening of a roofing membrane on a substrate, in particular a steel sheet.
In the case of flat roofs, the insulating material is optionally fastened to the substrate together with a roofing membrane arranged there above with the aid of screws and holding elements. The substrate can be, inter alia, a steel sheet, for example in the form of a steel trapezoidal sheet. Therefore, the fastening is described in the following predominantly with reference to a steel sheet substrate. The person skilled in the art knows, however, that the fastening can also be achieved in the same way for the case of other substrates.
With the aid of insulating materials of different thicknesses, a gradient can be formed on the outer side of the flat roof. The roof gradient is adapted, for example, such that rainwater can flow off in a desired direction on the roof. A typical value of such a roof gradient amounts to approximately 3%.
In the prior art, various screws and holding elements for fastening insulating materials on a flat roof are known. Due to the insulating materials of different thicknesses, screws and holding elements having however a plurality of different lengths must be used for the assembly. Since there is not a suitable screw with holding element for each possible insulating material thickness, the screws are screwed into the substrate to different depths. In the case of a substrate made of steel sheet, this has the disadvantage that the screws protruding to different extents can be seen from the underside of the roof, which may be perceived as an optical deficiency.
Therefore, the object exists to improve the assembly of insulating material in particular with gradient on a flat roof.
This object is solved by the gradient insulation screw, the system of gradient insulation screw and holding element, and the method for adjustable fastening of the independent claims. Advantageous embodiments are explained in the dependent claims.
In connection with the present invention, a gradient insulation screw is a screw, as it is defined by the further claim features. Such a screw is particularly well suited according to the invention to fasten, optionally with a corresponding holding element, a first element, such as, for example, an insulating material, to a second element, such as, for example, a substrate. Thereby, according to the invention, the fastening is particularly flexible, so that, for example, insulating material having different thicknesses, such as can be used, for example, to achieve a gradient, can be fastened with the aid of the screw.
A gradient insulation screw according to the invention for adjustable fastening of a roofing membrane on a substrate comprises: a drilling tip with a first direction of rotation, following the drilling tip an assembly thread with a second direction of rotation, which differs from the first direction of rotation, following the assembly thread a first thread-free region, following the first thread-free region an adjustment thread with the first direction of rotation, wherein the outer diameter of the adjustment thread is greater than the outer diameters of the assembly thread and the drilling tip, and following the adjustment thread a tool holder.
The present invention has the technical advantage that particularly insulations for achieving a gradient can be fastened, in particular on steel sheets, using the screw according to the invention with only one length or with at least a substantially smaller number of different lengths. Because with the aid of the adjustment thread, the length of the fastening system consisting of the screw and a holding element can be adjusted to different lengths.
In addition, the screws according to the invention have the advantage that, in the final assembly state, they protrude to the same extent from the underside of the steel sheet. Because, when the screw according to the invention is used as intended, in the final assembly state—independently of the thickness of the insulating material to be fastened—the assembly thread is located below the steel sheet, the first thread-free region is located in the opening in the steel sheet, and the adjustment thread is located above the steel sheet (i.e., the side with the insulating material).
In addition, the combination according to the invention of the threads and the drilling tip with different directions of rotation prevents the screw from moving within the opening in the steel sheet, i.e., from looking more or less out on the underside, when adjusting the length of the fastening system consisting of screw and holding element. Because, by rotating the screw in the second direction, the holding element moves in the direction of the steel sheet and can thus be shortened, but the adjustment thread cannot run into the opening in the steel sheet and thus influence the fastening of the screw in the steel sheet.
The gradient insulation screw according to the invention consists of regions, such as the drilling tip, various threads and thread-free regions, which extend starting from the front end to the rear end. The front end of the screw is that end of the screw, which is first moved into the substrate during the assembly, and the rear end of the screw is the opposite end, which is closest to the surface of the roofing membrane at the end of the assembly. The order of the individual regions is determined in that one region follows another region. However, it is clear to the person skilled in the art that these regions do not necessarily have to follow one another directly. The person skilled in the art also knows additional regions, which can be arranged between the regions following one another. Examples of this are the further threads and thread-free regions, which are described in the following.
In general, a screw consists of a core and a thread arranged on the core, wherein the radial expansion of the screw can be described with the aid of two diameters. Thereby, the core diameter is the diameter of the core of the screw and the outer diameter is the diameter of the screw, taking into account the thread arranged on the core. The thread has a pitch, wherein the pitch denotes the path that is covered during a full rotation. A thread-free region of a screw consists only of the core and comprises no thread. Accordingly, in this region, the core diameter corresponds to the outer diameter. In addition, screws can comprise threads with different directions of rotation. Thereby, in general, right-handed threads and left-handed threads are distinguished. A drilling tip is a tip of a screw, which is designed to drill a hole into a substrate. Therefore, a drilling tip is similar to the design of a driller. The drilling tip generally comprises a body with one or more recesses and/or one or more projections. The diameter of the body can change, in particular become greater, over the longitudinal extension of the drilling tip from the tip of the drilling tip in the direction of the assembly thread following thereon. The diameter of the body at its thickest location, for example at the transition to the assembly thread, can be referred to as core diameter and the largest diameter of the drilling tip, taking into account any projections, as outer diameter. In connection with invention, the body of the drilling tip may comprise different shapes. The body may, for example, be designed to be conical overall or a frustoconical or cylindrical body may follow the tip of the drilling tip. The optionally present projections may be cutting edges and/or a thread arranged on the drilling tip.
The gradient insulation screw according to the invention comprises at least two threads and a drilling tip. The drilling tip and the threads have alternating directions of rotation, seen from the drilling tip of the gradient insulation screw. According to a preferred embodiment, the screw may comprise a right-handed drilling tip, a left-handed assembly thread and again a right-handed adjustment thread. According to an alternative embodiment, a left-handed drilling tip, a right-handed assembly thread and again a left-handed adjustment thread are used. The assembly thread and the adjustment thread can have the same pitch, i.e., when the gradient insulation screw is rotated, it can undergo the same axial advance, independently of whether the advance of the screw is carried out by the assembly thread or by the adjustment thread.
Below, the invention is described by way of example with reference to the embodiment with a right-handed drilling tip, a left-handed assembly thread and again a right-handed adjustment thread. However, this does not mean that the invention is limited to this embodiment.
After the drilling tip has been screwed in in a first direction of rotation, the assembly thread is screwed in the substrate, for example the steel sheet, by a change to a second direction of rotation. At the end of the assembly thread, the first thread-free region follows. When the assembly thread is moved through the steel sheet during the assembly by rotating the gradient insulation screw in the second direction of rotation, the steel sheet is afterwards located in this first thread-free region. Since no thread is located in this region, the gradient insulation screw can then be further rotated without it moving further into the steel sheet.
The adjustment thread is designed to adjust, together with a holding element of a fastening system, the length of the fastening system consisting of screw and holding element. According to the invention, the outer diameter of the adjustment thread is greater than the outer diameter of the drilling tip and the outer diameter of the assembly thread so that the screw according to the invention can be connected to a holding element in a simple manner. Thus, first the drilling tip and then the assembly thread of the screw can be guided, during connection to the holding element, through a hollow shaft of the holding element until the adjustment thread engages in the hollow shaft.
In a preferred embodiment of the gradient insulation screw according to the invention, a second thread-free region is arranged between the drilling tip and the assembly thread. The second thread-free region has a length on which the gradient insulation screw must be pushed through the steel sheet until the assembly thread is started to be screwed into the steel sheet. This has the technical advantage that, as a result of a longer axial movement of the gradient insulation screw, it is indicated to the assembling person that the hole has been drilled in the substrate. As a result, the assembling person better recognizes the point in time at which the direction of rotation must be changed, since the drilling process takes place deep in the interior of the insulating material and is thus invisible for the assembling person.
The arrangement of a region, such as the just described second thread-free region, between two other regions of the gradient insulation screw according to the invention merely defines the order of the individual regions of the gradient insulation screw. The arrangement of the region between two other regions does not necessarily mean that these regions have to follow one another directly. In connection with the present invention, further regions can be arranged between these regions.
In a further preferred embodiment of the gradient insulation screw according to the invention, a preassembly thread with the first direction of rotation is arranged between the drilling tip and the assembly thread. The preassembly thread can have the same pitch as the adjustment thread. This preassembly thread supports the arrangement of the gradient insulation screw in the substrate as intended. As soon as the preassembly thread engages in the substrate, the movement of the gradient insulation screw relative to the substrate depends on the rotation of the screw and not on the pressure exerted by the assembling person. The preassembly thread can follow the drilling tip directly. In connection with the present invention, however, other regions can also be arranged between the drilling tip and the preassembly thread, such as, for example, the above-described second thread-free region.
According to a further preferred embodiment of the gradient insulation screw according to the invention, a third thread-free region is arranged between the preassembly thread and the assembly thread. This third thread-free region enables a simple change of the direction of rotation from the preassembly thread with the first direction of rotation to the assembly thread with the second direction of rotation.
In a further preferred embodiment of the gradient insulation screw according to the invention, the preassembly thread and the assembly thread comprise substantially the same outer diameter and/or core diameter. Alternatively, the preassembly thread may comprise a smaller outer diameter and/or core diameter as compared to the assembly thread. Both have the technical advantage that the assembly thread can further use the opening formed in the steel sheet by the drilling tip and/or the preassembly thread. As a result, the expenditure of force when using the assembly thread is reduced.
In a further preferred embodiment of the gradient insulation screw according to the invention, the drilling tip comprises at least one cutting element. This has the technical advantage that the gradient insulation screw can be placed in a simple manner without pre-drilling in the roofing membrane or in the steel sheet. The cutting element enables a positionally accurate initial placing of the gradient insulation screw.
In connection with the present invention, the drilling tip comprises a first direction of rotation. The drilling tip is therefore adapted to drill into a substrate when it is rotated in the first direction of rotation. In principle, such a drilling tip is similar to the design of a driller. The drilling tip generally comprises a body with a tip and one or more recesses and/or one or more projections. As described above, the body of the drilling tip may comprise different shapes. A frustoconical or cylindrical body may, for example, follow the tip of the drilling tip. The body may, however, also be adapted to be conical overall.
In a preferred embodiment of the gradient insulation screw according to the invention, the drilling tip comprises a tip at the front end, i.e., at the end that first appears on the substrate during the assembly. This tip preferably comprises at least one main cutting edge, which is aligned at an angle to the axis of rotation of the gradient insulation screw. The at least one main cutting edge forms the first opening in the substrate in most applications. The at least one main cutting edge preferably extends from the axis of rotation of the gradient insulation screw at an angle radially outwards.
In a further preferred embodiment of the gradient insulation screw according to the invention, the drilling tip comprises at least one secondary cutting edge. The at least one secondary cutting edge is arranged on the lateral surface of the body of the drilling tip. The secondary cutting edge enlarges the drilling hole and removes any drill residues. The at least one secondary cutting edge is preferably arranged on the outer side of the lateral surface in such a way that it protrudes as a projection at least partially in relation to the body.
Along the at least one main cutting edge and/or the at least one secondary cutting edge, a chip groove extends in a further preferred embodiment. The chip groove extends substantially in the direction of the axis of rotation of the gradient insulation screw and it is adapted to assist in the removal of the drilling chips.
The cutting edges of the drilling tip are designed to drill a drilling hole into the substrate when the drilling tip is rotated in the first direction of rotation. In particular, the at least one secondary cutting edge and the at least one chip groove can then be adapted in such a way that when the drilling tip is rotated in the first direction of rotation, the secondary cutting edge first cuts at the substrate and then the chip groove follows. Further preferred, the at least one secondary cutting edge and the chip groove are arranged in a spiral shape, wherein the spiral is preferably arranged like a thread with which the drilling tip can be screwed into the substrate.
In yet a further preferred embodiment of the gradient insulation screw according to the invention, the third thread-free region comprises a length in the longitudinal direction of the gradient insulation screw which is greater than the thickness of the steel sheet. This simplifies the changing of the direction of rotation of the gradient insulation screw during the assembly from the first direction of rotation to the second direction of rotation.
In a further preferred embodiment of the gradient insulation screw according to the invention, the first thread-free region comprises a diameter which is smaller than or equal to the greater of the outer diameter of the drilling tip and the core diameter of the assembly thread. When the screw also comprises a preassembly thread, the diameter of the first thread-free region is smaller than or equal to the greatest of the outer diameter of the drilling tip and the core diameters of the preassembly thread and the assembly thread. In most cases, the diameter of the drilling into the substrate is dependent on the outer diameter of the drilling tip and the core diameter of the assembly thread and, if applicable, of the preassembly thread. The use of a first thread-free region, the diameter of which is smaller than or equal to this outer diameter and these core diameters, ensures that the screw can be freely rotated when the first thread-free region is located in the steel sheet.
In yet a further preferred embodiment of the gradient insulation screw according to the invention, the first thread-free region comprises a length in the longitudinal direction of the gradient insulation screw which is greater than the thickness of the steel sheet. As a result, the screw according to the invention can move relatively freely in the opening in the steel sheet during the adjustment of the length of the fastening system, without the integrity of the fastening being impaired. This is helpful, for example, when pressure is exerted on the fastening system from above, for example when walking on the roof. Then, the screw can move downwards at times in the opening in the steel sheet and can move upwards again.
In yet a further preferred embodiment of the gradient insulation screw according to the invention, a thickening follows the first thread-free region. This thickening can also be referred to as a collar. The diameter of the collar or of the thickening is greater than the diameter of the first thread-free region. A thickening or a collar following the first thread-free region has the technical effect that it can be prevented with simple means that the adjustment thread engages in the steel sheet. In principle, the thickening can also be adapted as a rotationally symmetrical ramp, via which the diameter of the gradient insulation screw, in the direction of the adjustment thread, increases to the core diameter of the adjustment thread, starting with the diameter of the first thread-free region. In this case, the ramp serves a continuous thickness design of the gradient insulation screw.
The above object is also solved by a system of the gradient insulation screw according to the invention and a holding element. Hereby, the holding element comprises a holding plate and a hollow shaft, which follows the holding plate and which is adapted such that the adjustment thread of the gradient insulation screw can engage in the hollow shaft. As a result, a simple, but also particularly effective fastening of a roofing membrane on a steel sheet is provided. Because with the aid of the adjustment thread, the position of the holding element on the gradient insulation screw and thus the length of the system can be varied. As a result, the system can be used for a plurality of different thicknesses of insulating material.
In a preferred embodiment of the system according to the invention of gradient insulation screw and holding element, the hollow shaft of the holding element comprises projections, which are adapted complementary to the adjustment thread of the gradient insulation screw. Hereby, this can be a complementary internal thread. The person skilled in the art also knows, however, that an interplay with a thread can also be achieved by individual projections, which are not adapted as threads.
In an alternative embodiment, the complementary thread in the hollow shaft is formed for the first time when the gradient insulation screw is screwed into the hollow shaft. Preferably, the inner diameter of the hollow shaft of the holding element is smaller than the outer diameter of the adjustment thread, but greater than the core diameter of the adjustment thread. This enables that the adjustment thread taps and/or cuts into the material of the hollow shaft of the holding element and thereby a mother thread forms during the screwing in for transmission of force between gradient insulation screw and holding element in the hollow shaft. Via the transmission of force, suction forces by wind, which act on the roof membrane, can be efficiently dissipated.
In a further preferred embodiment of the system according to the invention of gradient insulation screw and holding element, the inner diameter of the hollow shaft of the holding element is greater than the outer diameters of the drilling tip, the preassembly thread (if present) and the assembly thread of the gradient insulation screw. This enables a simple connection of the holding element to the adjustment thread of the gradient insulation screw. Thus, the gradient insulation screw can be guided, during connection to the holding element, with the tip leading into the hollow shaft of the holding element until the adjustment thread engages in the hollow shaft.
In yet a further preferred embodiment of the system according to the invention of gradient insulation screw and holding element, the gradient insulation screw is made of a material which is harder than the material of the holding element.
In yet a further preferred embodiment of the system according to the invention of gradient insulation screw and holding element, the gradient insulation screw is made of metal and the holding element is made of plastic.
The above object is also solved by a method for the adjustable fastening of a roofing membrane on a steel sheet by means of the system according to the invention of gradient insulation screw and holding element, wherein the method comprises the following steps: pushing the drilling tip of the gradient insulation screw of the system into the roofing membrane in the direction of the steel sheet located underneath, screwing the drilling tip of the gradient insulation screw into the steel sheet in the first direction of rotation, screwing the assembly thread of the gradient insulation screw into the steel sheet in a second direction of rotation, which differs from the first direction, until the first thread-free region of the gradient insulation screw is located in the steel sheet, and further rotating the gradient insulation screw in the second direction of rotation, until the holding plate of the holding element of the system rests on the roofing membrane. The method according to the invention enables a simple and reliable fastening of the roofing membrane on the steel sheet.
In particular, at the end of the assembly method according to the invention, the holding plate can rest on the roofing membrane in such a way that a surface-flush termination with the roofing membrane occurs. I.e., it is possible that the surface of the holding plate lies in a plane with the roofing membrane, so that no irregularities arise on the assembled roofing membrane due to the assembled holding plates.
If the pushing of the drilling tip of the gradient insulation screw of the system made of gradient insulation screw and holding element into the roofing membrane in the direction of the steel sheet located underneath leads to a resting of the holding plate on the roofing membrane, but does not lead to a contact of the drilling tip with the steel sheet, the method according to the invention may further comprise: screwing the adjustment thread of the gradient insulation screw in the first direction of rotation into the holding element until the drilling tip comes into contact with the steel sheet.
If the gradient insulation screw has a preassembly thread, the method according to the invention may further comprise: screwing the preassembly thread of the gradient insulation screw in the first direction of rotation into the steel sheet until the second thread-free region of the gradient insulation screw is located in the steel sheet. As a result, it is achieved that the adjustment thread is screwed a minimum distance in depth into the holding element. The minimum distance amounts to the length of the preassembly thread. As a result, the risk of a detachment of the holding plate from the screw during the assembly is minimized. In addition, pressure exerted by the assembling person from above on the system consisting of gradient insulation screw and holding plate is dissipated by the preassembly thread onto the steel sheet. Thus, any impact of the assembly thread on the drilling hole in the steel sheet is avoided. As a result, it is avoided that neither the drilling hole nor the assembly thread are damaged by impact, which would result in a less reliable assembly of the roofing membrane.
As already explained above, the invention is described with reference to an exemplary embodiment with a right-handed drilling tip, a left-handed thread and again a right-handed thread. However, this does not mean that the invention is limited to this embodiment. The alternative embodiment with a left-handed drilling tip, a right-handed thread and again a left-handed thread can be used in the same way.
In a preferred embodiment, first an insulating material and then a roofing membrane is applied on a steel sheet. The roofing membrane can contain markings at regular, possibly grid-shaped positions, at which systems according to the invention of gradient insulation screw and holding element are to be introduced. It is possible, but not necessary, that pre-drillings are already located in the roofing membrane at the regular positions.
Preferably, the two parts of the system, the gradient insulation screw and the holding element, are connected to one another before pushing in the drilling tip of the system. This connection can take place, for example, at the construction site or directly after the production of the two parts. On the construction site, a gradient insulation screw with holding element is then pushed into the roofing membrane, for example, at one of the regular positions. The pushing in can be supported by a right-hand turning of the gradient insulation screw. In principle, however, the gradient insulation screw can also be pushed directly into the roofing membrane without rotation. The drilling tip of the gradient insulation screw is guided down through the insulating material onto the steel sheet. By pressure from above on the tool holder or by rotating the tool holder, respectively, the drilling tip of the gradient insulation screw is also pushed through the steel sheet. By right-hand rotation, the preassembly thread is now optionally screwed into the steel sheet. The holding element is thereby held by the insulating material such that it does not also rotate.
As soon as the steel sheet has migrated over the drilling tip and optionally over the preassembly thread of the screw, the screw does not move further into the substrate. Instead, due to continued right-handed rotation relative to the holding element, the holding plate can lift off from the roofing membrane noticeably for the assembling person. This gives the assembling person an indication that the direction of rotation must now be changed, in the present example into the left-handed run. In connection with the method according to the invention, the assembly thread is then screwed in by left-handed rotation until the steel sheet is located in the first thread-free region of the screw. In addition, the left-handed rotation has the effect of that the holding element moves with the holding plate again in the direction of the substrate.
For the system according to the invention, the adjustment thread of the gradient insulation screw is arranged during the assembly at least partially in the hollow shaft of the holding element. The adjustment thread engages into the hollow shaft, for example into an internal thread located there, which is formed for example by the screwing in of the adjustment thread into the hollow shaft. However, as already explained above, the adjustment thread can also engage in the hollow shaft differently.
As long as the holding element does not touch the roofing membrane and/or the insulation, the holding element rotates with the screw. However, when the holding element contacts the roofing membrane and/or the insulation, the screw rotates relatively to the holding element. Depending on the rotational movement of the screw, the holding element then moves in the direction of the steel sheet or away from the steel sheet.
In a preferred embodiment, the holding element is adapted such that it is held in the roofing membrane and/or the insulating material in a force-fitting and/or form-fitting manner. Thus, the holding element can, for example, comprise projections on the surface contacting the insulating material, which prevent co-rotation of the holding element during rotation of the screw.
In connection with the present invention, the screw is rotated further in the left-handed direction when the steel sheet is located in the first thread-free region. Due to the first thread-free region, the gradient insulation screw then does not penetrate further into the steel sheet. In addition, due to the continued left-handed rotation, the assembly thread is prevented from threading into the steel sheet again and thus the screw being rotated out of the steel sheet again. However, the screw rotates relatively to the holding element, for example, due to the above-described contact of the holding element with the roofing membrane and/or with the insulation. Due to the interplay of the hollow shaft of the holding element and the right-handed thread of the adjustment thread, the holding element moves in the direction of the steel sheet.
The invention is now explained in more detail with reference to the attached drawings. This results in further details and features of the subject-matter of the invention. In the drawings:
An assembly thread 7, which is a left-handed thread in the exemplary embodiment shown here, follows the drilling tip 4. In the present example, the assembly thread 7 has substantially the same core diameter as the drilling tip 4.
A first thread-free region 8 follows the assembly thread 7 in the embodiment of the gradient insulation screw 1 according to the invention shown in
According to the invention, the adjustment thread 9 has an outer diameter which is greater than the outer diameters of the drilling tip 4 and the assembly thread 7. A tool holder 10, with which a rotational movement can be transmitted to the screw, follows the adjustment thread 9.
In the exemplary embodiment shown in
The embodiment of the gradient insulation screw 1 according to the invention shown in
In the exemplary embodiment of the gradient insulation screw 1 shown in
In the present exemplary embodiment, the core diameter and/or the outer diameter of the preassembly thread 5 and that of the core diameter and/or the outer diameter of the assembly thread 7 are of the same size. In connection with the present invention, however, the core diameter and/or the outer diameter of the preassembly thread 5 can also be smaller than the core diameter and/or the outer diameter of the assembly thread 7.
In the exemplary embodiment of the gradient insulation screw 1 according to the invention shown in
A cutting element of the drilling tip is, in the embodiment shown in
As can be seen from the synopsis of
The holding element 12 comprises at least two parts, a holding plate 13 and a hollow shaft 14. The holding plate 13 is adapted to rest on the roofing membrane, and thus to hold downwards the roofing membrane and the insulation arranged thereunder. The hollow shaft 14 is adapted such that the adjustment thread 9 can engage in the hollow shaft 14. In the embodiment shown in
In the embodiment shown, the inner diameter of the hollow shaft 14 is smaller than the outer diameter of the adjustment thread 9 of the gradient insulation screw 1, but greater than the core diameter of the adjustment thread 9 of the gradient insulation screw 1.
In
When the drilling tip 4 and optionally the second thread-free region 4a penetrate the steel sheet 3, this causes an axial movement of the gradient insulation screw 1 in the direction of the substrate. The rotation of the adjustment thread 9 of the gradient insulation screw 1 in the hollow shaft 14 of the holding element 12 in the first direction of rotation has the effect of that the holding element 12 moves axially and relative to the gradient insulation screw 1 upwards, i.e., away from the substrate. When, due to the screwing in, the holding element 12 moves upwards more quickly relative to the gradient insulation screw 1 than the gradient insulation screw 1 moves in the direction of the substrate due to the lowering of the drilling tip 4 and the second thread-free region 4a through the steel sheet 3, the distance between the holding plate 13 of the holding element 12 and the roofing membrane 2 increases. If the drilling tip 4 and optionally the second thread-free region 4a move faster through the steel sheet 3 than the holding element 12 moves away from the gradient insulation screw 1, the distance between the holding plate 13 of the holding element 12 and the roofing membrane 2 decreases. When both movements take place almost equally quickly, the distance of the holding plate 13 from the roofing membrane 2 does not change.
In the embodiment shown in
By the rotation of the gradient insulation screw 1 in the second direction of rotation, here in the left-handed direction and optionally by slight pressure from above on the gradient insulation screw 1, the assembly thread 7 of the gradient insulation screw 1 now engages in the steel sheet 3 and the assembly thread 7 is screwed into the steel sheet 3 until the steel sheet 3 is located in the first thread-free region 8, as shown in
In this case, the holding plate 13 of the holding element 12 is lowered again in the direction of the roofing membrane 2, since firstly the gradient insulation screw 1 passes further downward through the steel sheet 3 and since secondly, due to the left-handed rotation, the holding element 12 moves in the direction of the drilling tip 4 of the gradient insulation screw 1. This is indicated in
A possible thickening 8a, which follows the end of the thread-free region 8 facing the adjustment thread 9, can prevent the steel sheet 3 from not being pressed out of the first thread-free region 8 in the direction of the adjustment thread 9 despite pressure from above on the gradient insulation screw 1, e.g., by a battery-operated screwdriver.
With continued rotation of the gradient insulation screw 1 in the second direction of rotation, as shown in
When using an additional preassembly thread on the gradient insulation screw, the steps of
By subsequent left-handed rotation of the gradient insulation screw 1 and optionally by slight pressure from above on the gradient insulation screw 1, the assembly thread 7 of the gradient insulation screw 1 now engages in the steel sheet 3 and is screwed in until the steel sheet 3 is located in the first thread-free region 8, as shown in
As described above, a possible thickening 8a following the first thread-free region 8 can prevent the steel sheet 3 from not being pressed out of the first thread-free region 8 in the direction of the adjustment thread 9 despite pressure from above on the gradient insulation screw 1.
With continued left-handed rotation of the gradient insulation screw 1, as shown in
In
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 207 059.8 | Jun 2020 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/057881 | 3/26/2021 | WO |
