NL2010070C2

NL2010070C2 - Fastener.

Info

Publication number: NL2010070C2
Application number: NL2010070A
Authority: NL
Inventors: Robert Pieter Johan Hooijkaas; Gerrit Mol
Original assignee: Northern Engineering Services N E S B V
Priority date: 2012-12-28
Filing date: 2012-12-28
Publication date: 2014-07-03

Description

Nr. P100105NL00 Fastener 5 Field of the invention

The invention relates to a fastener

Background of the invention

Many fasteners are known that include a polymer or plastic part. GB1278351 for 10 instance discloses a bolt having a head, and a plastic part enclosing said head and having a skirt, said plastic part for preventing corrosion of the metal head of the bolt. GB 1372575 shows a similar bolt. G2338765 shows a nail with a plastic-enclosed head. US3396434 shows a fastener with a head that is largely polymer material. US415438 and US4235147 show a screw with a head enclosed with a plastic part. All these 15 fasteners have a metal head part.

US2002/0106259 discloses a polymer, threaded shank, threaded throughout its length and having a plastic head moulded on the threaded shank.

All these known fasteners use plastic heads for corrosion prevention.

20 Summary of the invention A disadvantage of prior art fasteners is that they cause an interruption in a construction when in use, in particular, this may lead to condensation locations in a construction.

Hence, it is an aspect of the invention to provide a fastener that reduces the 25 occurrence of potential condensation locations in a construction.

The invention thus pertains to a fastener comprising a metal shank comprising a threaded end, and a polymer part connected to said metal shank and comprising a head, wherein said polymer part further comprises a polymer shank extending from said head, said polymer shank enclosing at least part of said metal shank.

30 It was found that such a fastener reduces the occurrence of potential condensation locations in a construction.

In an embodiment, said polymer shank extends up to said threaded end.

2

In an embodiment, said metal shank extends in said polymer shank, ending before said head. In this way, it is possible to reduce the heat conductivity of the fastener from head to tip as much as possible, while maintaining enough strength to insert the fastener, i.e., to apply torque to the head.

5 In an embodiment, part of said enclosed metal shank part comprises at least one friction-increasing structure providing rotational-resistance against said metal shank rotating inside said polymer shank. In an embodiment, said resistance-increasing structure is arranged for working in an opposite direction as the thread on said metal shank part. In an embodiment, said resistance-increasing structure comprises a thread 10 running opposite to the thread on said threaded end.

In an embodiment, said polymer is a fibre-reinforced polymer. It was found that this material enables to withstand torque forced between the polymer part and the metal shank that occur when screwing in a fastener into a construction part, for instance a wooden beam. The polymer material in an embodiment is a composite polymer 15 material. An example of suitable material can be, but is not limited to, Akroloy®, or similar PA based materials. Such material may comprise a high amount of reinforcing material, for instance glassfiber or other suitable fiber material. The composite material may comprise more than 30 wt. % reinforcing material, in an embodiment more than 50 wt. %, in particular even more than about 60 wt. %.

20 In an embodiment, said polymer part is a moulded polymer part. Using moulding technique allows economic production of the fastener of the invention. Furthermore, it allows an intimate contact between the polymer material and the metal shank.

In an embodiment, said metal shank comprises a shoulder between said threaded end and said polymer shank. In an embodiment, said shoulder comprises a friction-25 increasing provision, in part working opposite said thread of said metal shank. The shoulder or rim or flange around the metal shank provides an abutment for the end or the polymer shank of the polymer part. It helps holding the polymer part onto the metal shank.

In an embodiment, said metal shank end that extends in said polymer shank has a 30 smaller cross section than said threaded end. In this respect, the cross sectional are of the threaded end is to be regarded at a location remote from the tip where the cross sectional area relatively constant. This further reduces the heat transfer parameter representing heat transfer from the head to the tip.

3

In an embodiment, said metal shank comprises an end opposite to said threaded end. That end is in an embodiment located near the head. The end of the metal shank can be provided with an end resistance-increasing structure. For instance, a groove cross to the longitudinal axis can be provided, or an alternative, similar indentation can 5 be provided in the end.

In an embodiment, said head of the polymer part comprises a tool-receiving provision for providing grip for a tool. In particular in case of a screw or bolt, the head can have for instance a hexagonal head, or another cross section suitable and known for use in combination with a known insertion tool gripping the head. Alternatively, the 10 head may be provided with a groove for engaging with a screwdriver, or the head can be provided with another shape of indentation, for instance a cross-slot for engaging a cross-slotted head driver, or a hexagonal wrench driver. Other types of indentations or slots are known in the art.

In this application, in particular a fastener relates to a screw or a bolt. In these 15 particular types of fasteners, the advantages of the current invention become more prone. In these types of fasteners, often the head extends or is located at or near an outer surface of a building, and the tip of the screw or bolt is located directed into the building. In an embodiment the fastener specifically is a screw. More in particular, the screw is a so-called self-tapping screw or self-drilling screw. In an embodiment, these 20 screws have a tip adapted to that end.

In an embodiment, the polymer shank comprises an external thread. In an embodiment, said external thread is provided near the polymer head. Such a fastener is in particular suited for applying sheet material to a supporting structure. This sheet material may comprise a metal sheet, for instance tin sheet or tin-plate. The thread in 25 such a case pulls the sheet against the head and holds it in place. Other sheet material which can be fixed to a structure is for instance sheet material that is provided with an insulating layer. Such material can for instance be a thin metal sheet provided with insulating material like insulating foam. For instance, a sheet of two tin plates or other thin sheet material with insulating foam material sandwiched between the sheets or 30 plates can be fixed very well using the current fastener. In particular, if the fastener further comprises a reamer at the transition from the metal tip to the polymer shank, these types of sheet or plate material can be fixed very well. In an embodiment, the cross section of said reamer is larger than a cross section of said polymer shank. In 4 particular if said polymer shank comprises an external thread, said reamer has a cross section which is substantially the cross section of that external thread. In particular said reamer has a cross section dimensioned between the diameter of the polymer shank and an external diameter of the cross section of that external thread.

5 The polymer shank in an embodiment may even extend in a covering layer covering the complete metal shank. Such a covering layer that covers the metal shank at the threaded end, in an embodiment is a thin layer. Often, the covering layer is substantially thinner than the wall of the polymer shank. If present, such a layer is less than 10% of the average wall thickness of the polymer shank enclosing the metal 10 shank.

The person skilled in the art will understand the term “substantially” in this application, such as in “substantially encloses” or in “substantially extends up to”. The term “substantially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially may also be removed. 15 Where applicable, the term “substantially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term “comprise” includes also embodiments wherein the term “comprises” means “consists of’.

Furthermore, the terms first, second, third and the like if used in the description 20 and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

25 The fasteners herein are amongst others described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation or devices in operation.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many 30 alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or 5 "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device or apparatus claims enumerating several means, several of these means may be 5 embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

The invention further applies to a fastener or parts thereof comprising one or more of the characterising features described in the description and/or shown in the 10 attached drawings. The invention further pertains to a method or process comprising one or more of the characterising features described in the description and/or shown in the attached drawings.

The various aspects discussed in this patent can be combined in order to provide additional advantages. Furthermore, some of the features can form the basis for one or 15 more divisional applications.

Brief description of the drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding 20 reference symbols indicate corresponding parts, showing an embodiment of a fastener, and showing in:

Figure 1 a perspective view of an embodiment of a fastener, in transparent view; Figure 2 an exploded view of the fastener of figure 1;

Figures 3-6 an alternative embodiment of a fastener, and 25 Figure 7 yet another alternative embodiment for the metal shank.

The drawings are not necessarily on scale

Description of preferred embodiments

Figure 1 shows an example of a fastener 1, here a screw. The invention, as 30 explained above, is not limited to such a specific fastener. Fastener 1 comprises a metal shank 2. Metal shank 2 has a threaded end 3. The threaded end 3 here is provided with a screw thread, or shortly ‘thread’, 4 that has a first thread direction for pulling the fastener into a workpiece or construction part when rotating the fastener 1 clockwise. A

6 workpiece or construction part may for instance be a wooden beam, plate material, thin steel sheet, steel purlins (construction), construction steel like for instance H and I beams, and the like. The threaded end 3 ends here in a tip 13, here a self-drilling point or other sharp tip 13 designed as a drill end for easily applying the fastener into a 5 workpiece.

The fastener 1 further has a polymer part 5. The polymer part 5 is connected to the metal shank 2. Polymer part 5 comprises a head 6. In this embodiment, the head 6 has a hexagonal end for receiving a tool, for instance a wrench. Other types of heads may be possible. Also, or alternatively, the head may be provided with a groove or 10 other indentation for receiving a tool, for instance a screwdriver. The polymer part 5 further comprises a polymer shank 7. The polymer shank 7 extends from the head 6. The polymer shank 7 further encloses at least part of the metal shank 2. The head 6 and shank 7 are intimately connected. Here, the head 6 and the shank 7 are integrally formed.

15 In this embodiment, the head further comprises an integrally formed washer 16.

Here the washer 16 has an integrally formed skirt portion 17 providing an annular surface at the underside of the washer. Thus, a better sealing may be provided.

The metal shank 2 here has a collar or shoulder 11. Here, the shoulder 11 provides an abutment for the end of the polymer shank 7. In order to accommodate 20 more easy insertion of the fastener in a workpiece, the surface of the collar directed towards the threaded end 3 of the metal shank 2 is slanted upward, away from the threaded end 3. In particular, the shoulder or flange 11 is here frusto-conical. The opposite portion of the shoulder 11 that is directed towards the end of polymer shank 7 is provided with resistance-increasing provisions 12. These resistance-increasing 25 provisions 12 on the shoulder 11 provide resistance against rotation of the polymer shank 7 with respect to the metal shank 2 when torque is applied to the fastener 1. The resistance-increasing provisions 12 may be indentations. Here, the resistance-increasing provisions 12 on the shoulder 11 are saw-toothed.

The opposite end 8, opposite to the threaded end 3, of the metal shank 2 is 30 provided with friction-increasing structures 9. These structures 9 increase friction between the inner surface or the polymer shank 7 and the opposite end 8 of the metal shank 2. Usually, the polymer shank fits tightly around the metal shank 2. In this embodiment, the opposite end 8 is provided with a thread 9 that runs opposite to the 7 thread 4 of the treaded end 3. In particular in combination with the shoulder 12 this prevents the polymer part 5 from disengaging the metal shank 2.

In this embodiment, the opposite end 8 of metal shank 2 runs in the polymer shank 7 up to a distance from the head 6. This distance is a trade off between the 5 required heat conductivity of the fastener 1, and the allowable torque. The opposite end 8 may run all the way up until the head 6. Alternatively, for instance, cross sectional area of metal shank 2 towards end 10 may be reduced in order to decrease heat conductivity of the fastener as a whole. This may allow the end 10 for instance to extend into head 6.

10 In this embodiment, at least part of the polymer shank 7 is provided with (external) thread 14. In this embodiment, only an upper part of the polymer shank near head 6 is provided with thread 14. In this way, it is for instance possible to connect two constructional parts that are a distance apart. For instance, the thread 4 may extend in an inner construction, the thread 14 engages for instance a plate material, and between 15 the plate material and the inner construction, insulating material is provided.

The metal shank can be made of any metal known for making for instance screws or bolts. For instance, carbon steel, stainless (in-ox) steel, brass, cupper, are known metals for this purpose.

The polymer part 5 is produced from a polymer material that is able to withstand 20 for instance the torque forces that come with screwing in a screw, of bolting together constructional elements. It was found the fiber-reinforced polymer material is a suited material. For instance, the polymer is a thermoplastic polymer, allowing for instance injection-moulding production of the fastener 2. Suitable thermoplastic material is for instance engineering plastic, based on PE, PP, nylon, PVC, and the like.

25 In figures 3-6, al alternative embodiment of the fastener is provided. In these drawings, metal shank of figure 4 is depicted on a larger scale than figure 6. Figure 3 shows a top view of figure 4, and figure 5 shows a top view of figure 6. In fact, the metal shank of figure 4 extends almost up to the external thread 14 in the polymer shank 7.

30 The metal shank 2 of figure 4 has several friction-increasing features 9, 9’,9” which are here combined but which may also be applied separately or with the embodiment discussed above. First, the metal shank has a cross-carved structure 9 which as such is known from hand-tools. It may be produced using knurling 8 techniques. This proved to be easy to make, and provides a good friction-increasing provision, in particular if the polymer part is tightly injection moulded around the end 8 of metal shank 2. Furthermore, the metal shank 2 has a friction-increasing thread 9’ provided here at end 8 of metal shank 2. Here, this thread 9’ has the same direction as 5 the thread 4 of metal shank 2.

In its head 10, the metal shank 2 has a further friction-increasing provision 9”. In fact, this friction-increasing provision is provided in the top of the head 10 of the metal shank 2. The indentation 9” here has a rectangular cross section, but other cross sections may be possible. Its depth may be several millimetres, but may extend up to 10 one or more centimetres, also depending on the size of the fastener 1.

The fastener in this embodiment further comprises a reamer 17. One of the purposes of this reamer 17 is to prevent damage to the polymer shank. In figure 4 the reamer at the transition where the polymer shank is to start stops abruptly, in figure 6 the transition is more smoothly. In the embodiment of figures 3-6, the reamer is 15 situated at the transition where the polymer shank 7 starts. Other positions may be possible.

In figure 6, several diameters dl-d3 are indicated. Here, dl is the diameter of the reamer, d2 is the diameter of the (external) thread 14 on the polymer shank 7, and d3 is the diameter of the polymer shank 7. It is clear that diameter d3 of the polymer shank is 20 larger than the diameter (not indicated) of the metal shank 2 at end 8. In fact, the diameter d3 should also be larger than the outer diameter of the friction-increasing provision 9’ and of the head 10 of the metal shank 2.

The diameter dl of the reamer usually is a little smaller than the diameter of the thread 14. This often is a trade-off between preventing too much damage to the thread 25 14, and allowing thread 14 to force itself into the material into which the fastener is inserted or screwed-in.

In figure 7, yet an alternative embodiment of the metal shank 2 is depicted. In this embodiment, the friction-increasing provision 9’ near the hear is less profound. In fact, using punching or die-cutting techniques, the extending thread-like parts can be 30 punched from the shank surface.

In this embodiment, also the reamer has a structure that differs from the reamer shown in figure 4. The, the reamer 17 may be punched from the shank material, making it very simple to produce.

9

Fastener 1 can be produced in the following way. The metal shank can be produced in a manner known as such, for instance methods for making screws, bolts, of even drills. Next, one or more metal shanks are provided in an injection mould and polymer material is injected to produce one or more fasteners. In an alternative method, 5 the polymer part is produced with an at least partly hollow polymer shank 7. Next, the metal shank is inserted in a tight fit, for instance screwed in into the polymer shank 7.

It will also be clear that the above description and drawings are included to illustrate some embodiments of the invention, and not to limit the scope of protection. Starting from this disclosure, many more embodiments will be evident to a skilled 10 person. These embodiments are within the scope of protection and the essence of this invention and are obvious combinations of prior art techniques and the disclosure of this patent.

Claims

1. Een bevestigingsmiddel (1) omvattende een metalen staaf (2) omvattende een van draad voorzien eind (3), en een polymeer deel (5) verbonden met de metalen staaf (2) en omvattende een kop (6), waarbij het polymere deel (5) verder een polymere staaf (7) omvat die zich uitstrekt vanaf de kop (6), waarbij de polymere staaf (7) ten minste een deel van de metalen staaf (2) omsluit.A fastener (1) comprising a metal rod (2) comprising a threaded end (3), and a polymer part (5) connected to the metal rod (2) and comprising a head (6), wherein the polymeric part (5) further comprises a polymeric rod (7) extending from the head (6), the polymeric rod (7) enclosing at least a portion of the metal rod (2).

2. Het verbindingsmiddel volgens conclusie 1, waarbij de polymere staaf zich uitstrekt tot aan het van draad voorziene eind.The connecting means of claim 1, wherein the polymeric rod extends to the threaded end.

3. Het verbindingsmiddel volgens conclusies 1 of 2, waarbij de metalen staaf zich 15 uitstrekt in de polymere staaf, en eindigt voor de kop.3. The connecting means according to claims 1 or 2, wherein the metal bar extends into the polymer bar, and ends before the head.

4. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij een deel van de ingesloten metalen staaf deel ten minste een weerstand verhogende structuur omvat voor het verschaffen van rotatie-weerstand tegen draaien van de 20 metalen staaf in de polymere staaf.4. The connecting means according to one or more of the preceding claims, wherein a part of the enclosed metal bar part comprises at least one resistance-increasing structure for providing rotational resistance to rotation of the metal bar in the polymer bar.

5. Het verbindingsmiddel volgens de voorgaande conclusie, waarbij de weerstand verhogende structuur is aangepast voor het werken in een richting tegengesteld aan de draad op het metalen staaf deel. 25The connecting means according to the preceding claim, wherein the resistance-increasing structure is adapted to work in a direction opposite to the wire on the metal rod part. 25

6. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij de weerstand verhogende structuur een draad omvat welke tegengesteld loopt aan de draad op het van draad voorziene eind.The connector according to one or more of the preceding claims, wherein the resistance-increasing structure comprises a wire which runs opposite to the wire at the wire-provided end.

7. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij de polymeer een vezel versterkte polymeer is.The connector according to one or more of the preceding claims, wherein the polymer is a fiber-reinforced polymer.

8. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij het polymere deel een gegoten polymeer deel is.The connecting means according to one or more of the preceding claims, wherein the polymeric part is a cast polymeric part.

9. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij de 5 metalen staaf een schouder omvat tussen het van draad voorziene eind en de polymere staaf (7).9. The connecting means according to one or more of the preceding claims, wherein the metal bar comprises a shoulder between the threaded end and the polymer bar (7).

10. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij de schouder een weerstand-verhogende voorziening omvat, welke ten dele werkt 10 tegengesteld aan de draad van de metalen staaf.10. The connecting means according to one or more of the preceding claims, wherein the shoulder comprises a resistance-increasing device, which partially acts opposite to the wire of the metal rod.

11. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij de metalen staaf eind welke zich uitstrekt in de polymere staaf een kleinere diameter heeft dan het van draad voorziene eind. 15The connector according to one or more of the preceding claims, wherein the metal bar end that extends into the polymer bar has a smaller diameter than the threaded end. 15

12. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij de metal staaf een eind (10) omvat tegenover het van draad voorziene eind, welk eind van de metalen staaf voorzien is van een weerstand verhogende structuur, in het bijzonder een groef dwars op de lengteas. 20The connecting means according to one or more of the preceding claims, wherein the metal rod comprises an end (10) opposite the threaded end, which end of the metal rod is provided with a resistance-increasing structure, in particular a groove transverse to the longitudinal axis. 20

13. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij de polymere staaf een uitwendige draad (14) omvat, in het bijzonder een externe uitwendige draad bij de kop.The connector according to one or more of the preceding claims, wherein the polymeric rod comprises an external thread (14), in particular an external external thread at the head.

14. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij de metal staaf een ruimer omvat bij of nabij een overgang naar de polymere staaf, in het bijzonder is een dwarsdoorsnede van de ruimer groter dan een dwarsdoorsnede van de polymere staaf, in het bijzonder, in geval de polymere staaf een uitwendige draad (14) omvat, heeft de ruimer een dwarsdoorsnede welke in hoofdzaak 30 overeenkomt met de dwarsdoorsnede van de externe draad (14), meer in het bijzonder heeft de ruimer een dwarsdoorsnede met een afmeting tussen de diameter van de polymere staaf en een externe diameter van de dwarsdoorsnede van die externe draad (14).The connecting means according to one or more of the preceding claims, wherein the metal bar comprises a reamer at or near a transition to the polymer bar, in particular a cross section of the reamer is larger than a cross section of the polymer bar, in particular if the polymeric rod comprises an external thread (14), the reamer has a cross-section which substantially corresponds to the cross-section of the external thread (14), more particularly the reamer has a cross-section with a dimension between the diameter of the polymeric rod and an external diameter of the cross-section of said external wire (14).

15. Het verbindingsmiddel volgens een of meer der voorgaande conclusies, waarbij de kop voorzien is van een gereedschap-ontvangende voorziening voor het 5 verschaffen van grip voor een gereedschap, in het bijzonder is de kop een hexagonale kop, of is deze voorzien van een groef of soortgelijke gereedschap-ontvangende verdiepingen. -o-o-o-o-o-15. The connecting means as claimed in one or more of the foregoing claims, wherein the head is provided with a tool receiving provision for providing grip for a tool, in particular the head is a hexagonal head, or is it provided with a groove or similar tool-receiving floors. -o-o-o-o-o-