GB2578142A

GB2578142A - A fastening device

Info

Publication number: GB2578142A
Application number: GB1816986.2A
Authority: GB
Inventors: Sayers Steven
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-10-18
Filing date: 2018-10-18
Publication date: 2020-04-22
Anticipated expiration: 2038-10-18
Also published as: GB2578142B; GB201816986D0

Abstract

A fastening device 1 comprises a body having a first face 2, a second face 4a and a third face 5b. The second and third faces 4a, 5b are perpendicular to the first face 2 and parallel with each other. A hole 10 for receiving a threaded member extends into the body along an axis perpendicular to the first face 2. A cross section of the hole 10 normal to the axis has a shape where the shape has at least three vertices 12 with interior angles greater than 180 degrees.

Description

A FASTENING DEVICE

FIELD OF THE INVENTION

[0001] The present invention relates to a fastening device. BACKGROUND OF THE INVENTION [0002] Bolts and screws are examples of fasteners that have a threaded shaft that can be used to fasten components together, and each generally require either a circular pilot hole or a threaded hole in which they can be inserted.

[0003] However the geometry of the fastener must be closely matched to the geometry of the hole to which it is inserted. For instance, a screw may crack a component if the pilot hole is smaller than the inner thread diameter, whilst a bolt requires a threaded hole of the same thread pitch, pitch diameter, and thread angle. It would be beneficial to provide a fastener device that mitigates at least some of these difficulties.

SUMMARY OF THE INVENTION

[0004] A first aspect of the invention provides a fastening device comprising: a body having a first face, a second face, and a third face, the second and third faces being perpendicular to the first face, and the third face being parallel to the second face, an axis normal to the first face, and a hole for receiving a threaded member, the hole extending into the body along the axis, wherein a cross section of the hole normal to the axis has a shape, the shape having at least 3 first vertices with interior angles greater than 180°.

[0005] A threaded member is defined as any substantially cylindrical elongate rod with a helical protrusion extending around it, such as a screw or bolt.

[0006] The shape of the hole allows a wide variety of threaded members to be received without damaging the structural integrity of the fastening device. A collection of threaded members may vary in, for example, size and thread dimensions, but may all fasten securely inside the hole of the fastening device.

[0007] The parallel second and third faces may provide external gripping surfaces from which to react torque on the fastening device against the threaded member.

[0008] The shape may have at least 6 straight sides. With such an arrangement, the interior angles can be more easily deformed by the threaded member.

[0009] The shape may have at least 3 second vertices with interior angles less than 180°. With such an arrangement, the outer radial area of the hole may be reduced.

[0010] The shape may have an equal number of first vertices and second vertices. With such an arrangement, stress may he distributed uniformly around the fastening device.

[0011] The shape may have an odd number of first vertices and an odd number of second vertices. By providing an odd number of first and second vertices, the vertices can be evenly distributed whilst ensuring the stress field at the vertices does not align with the stress fields of other vertices. Overall, the chance of the fastening device cracking or splitting may be reduced [0012] The first vertices may be arranged along a first circle and/or the second vertices may be arranged along a second circle. With this arrangement, the inner and outer dimensions of the hole may be radially constant, giving a more even stress distribution when the fastening device is in use.

[0013] The second circle may encircle the first circle, and a diameter of the first circle may be at least 10% of a diameter of the second circle. With this arrangement, the stress in the hole may be reduced when receiving larger threaded members.

[0014] A diameter of the first circle may be no more than 95% of a diameter of the second circle. This may allow the hole to accept a broad size range of threaded members.

[0015] The inner and outer circles may be concentric about the axis. The first vertices may be equiangularly arranged about the axis and/or the second vertices may be equiangularly arranged about the axis. The first and second vertices may alternate circumferentially. Each of these properties may improve stress distribution around the hole.

[0016] The first vertices may have interior angles greater than 270°. With this arrangement, the threaded member can be held in the hole more resiliently.

[0017] The hole may include a bevelled edge adjacent the first face. The bevelled edge may help to guide the threaded member into the hole.

[0018] The hole may be tapered along the axis, optionally wherein the hole is tapered at 100 to the axis. The taper may help to guide the threaded member into the hole. As the hole gets smaller along the axis, due to the taper, the threaded member may be held increasingly more tightly. Thus, the fastening device may be more easy to use and may hold the threaded member more resiliently.

[0019] The fastening device may have a fourth face on an opposite side of the fastening device to the first face.

[0020] The hole may be a through-hole extending from the first face to the fourth face. With this arrangement, the fastening device may be threaded along a threaded member longer than the hole. Thus, the fastening device can be used with a greater range of threaded members in a greater range of applications.

[0021] A cross section of the body in a plane normal to the axis may have a polygonal shape and the body may he a polygonal prism. The straight sides of a polygonal prism may provide convenient gripping surfaces for handling and tightening the fastening device, improving the usability of the fastening device.

[0022] The outer shape of the body may be substantially unchanged when a threaded member is resiliently received by the hole. This means that the external faces of the threaded members may be of substantially constant dimensions, so that the gripping tool (e.g. spanner) dots not need to be changed during tightening of the fastening device.

[0023] At least one of the second and third faces may be adjacent to the first face. With this arrangement, the fastening device may be more compact.

[0024] A maximum radius of the hole may be no more than 80% of the maximum radial distance of the outer perimeter from (he axis. With this arrangement, high stress concentrations around the hole may he kept away from the outer perimeter of the fastening device. Thus, the fastening device may be less likely to suffer surface cracks and may be more resilient.

[0025] A maximum radius of the hole may be no less than 20% of the maximum radial distance of the outer perimeter from the axis. With this arrangement, the fastening device may be more compact.

[0026] The hole may have a depth of at least 50% of a maximum radial distance of the hole from the axis. With this arrangement, the fastening device may be held more resiliently in the hole than in a hole having a smaller depth.

[0027] The fastening device may be made of plastic, metal, or rubber, optionally wherein the fastening device is made of nylon. These materials may provide sufficient deformability to accommodate the threaded member, whilst also resiliently holding the threaded member.

[0028] The fastening device may be 3D printed. This may provide a fast and efficient manufacturing method.

[0029] The fastening device may have an interior volume formed from a foam or honeycomb structure. With this arrangement, the interior volume of the fastening device adjacent to the hole may he deformahle to accommodate the cutting and deformation actions of the threaded member when received in the hole.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Embodiments of the invention will now be described with reference to the accompanying drawings, in which: [0031] Figure 1 shows a perspective view according to a first aspect of the fastening device; [0032] Figure 2 shows a cross-section of the fastening device through Section A-A; [0033] Figure 3 shows a plan view of the first face; [0034] Figure 4 shows a cross-section of the fastening device through Section B-B; [0035] Figure 5 shows a plan view of the second face; [0036] Figure 6a shows the fastening device receiving a screw; [0037] Figure 6b shows the fastening device receiving a bolt; [0038] Figure 7a shows a second example of the fastening device; [0039] Figure 7b shows a third example of the fastening device; [0040] Figure 7c shows a fourth example of the fastening device; [0041] Figure 7d shows a fifth example of the fastening device; [0042] Figure 7e shows a sixth example of the fastening device; DETAILED DESCRIPTION OF EMBODIMENT(S) [0043] Figure 1 shows a fastening device 1 with a body, and a hole 10 extending into the body. The body of the fastening device 1 has a first face 2, a second face 3 parallel to the first face 2, opposing third and fourth faces 4a,4b perpendicular to the first and second faces 2,3, and opposing fifth and sixth faces 5a,5b perpendicular to the first and second faces 2,3 and perpendicular to the third and fourth faces 4a,4b. The cross-section of the hole 10 at the first face 2 includes eighteen sides 14 between first vertices 12 and second vertices 13. The hole 10 is shaped for receiving a threaded member, such as a screw or bolt.

[0044] As shown in figure 2, the hole 10 is a through-hole extending between the first and second faces 2,3 along an axis 11 normal to the first face 2. The hole 10 includes a first bevelled edge 15 adjacent to the first face 2, and a second bevelled edge 16 adjacent to the second face 3. The bevelled edges 15,16 create an increased diameter at the entrance of the hole 10 that make it easier for guiding a threaded member into the hole 10. The body of the fastening device 1 has rounded edges 16 between the adjacent faces.

[0045] The hole 10 is tapered along the axis 11 at an angle of approximately 10 degrees between the first face 2 and the second face 3, such that the maximum diameter of the hole 10 at the first face 2 is approximately 50% of the maximum diameter of the hole 10 at the second face 3. Preferably the taper is between 0 degrees and 25 degrees, and more preferably between 5 and 15 degrees. The taper is defined as the angle formed by the sides 14 of the hole 10 with respect to the axis 11, when viewed in a plane perpendicular to the axis 11.

[0046] The hole 10 has a depth of approximately 350% of the maximum radial distance of the hole 10 from the axis 11. Preferably the hole 10 has a depth of at least 50% of the maximum radial distance of the hole 10 from the axis 11, and more preferably at least 100%. The depth extends along the axis 11.

[0047] Figure 3 shows the cross-section of the hole 10 at the first face 2. The first vertices 12 have an interior angle of approximately 290 degrees and are arranged equiangularly along a first circle. Preferably the first vertices 12 have an interior angle of greater than 180 degrees, and more preferably greater than 270 degrees. The second vertices 13 have an interior angle of approximately 30 degrees and are arranged equiangularly along a second circle that encircles the first circle. Preferably the second vertices 13 have an interior angle less than 180 degrees, and more preferably less than 60 degrees.

[0048] The vertices 12,13 define a sharp edge between the respective adjacent sides 14 of the hole 10. Alternatively the edges 12,13 may be include a small curvature so that the planar sides 14 are contoured into adjacent sides 14.

[0049] The first circle and second circle are concentric about the axis 11, and the first and second vertices 12,13 alternate circumferentially about this axis 11. The diameter of the first circle is approximately 40% of the diameter of the second circle. Preferably the diameter of the first circle is between 10% and 95% of the diameter of the second circle, and more preferably is between 30% and 50% of the diameter of the second circle.

[0050] The area between the fu-st circle and second circle is therefore partially filled, such that part of the cross-section between the firs( and second circles forms part of the through-hole, and the remainder of the cross-section forms part of the interior volume of the fastening device I. [0051] The fastening device 1 is manufactured by 3D printing. The sides of the hole 14 and faces 2,3,4,5 of the fastening device I arc substantially solid, and enclose the honeycomb structure 20 of the interior volume, as shown in figure 4. The fastening device 1 could alternatively be manufactured by other methods, such as injection moulding, machining, pultrusion, or any other manufacturing method known in the art.

[0052] The cross-section of the hole l0 in each of the figures 3 to 5 is substantially the same, having nine first vertices 12 and nine second vertices 13 arranged circumferentially along two circles concentric about the hole axis 11. However, the diameters of the first and second circles decreases proportionally between the first face 2 and second face 3, due to the tapered cross-section of the hole 10, such that the diameter of the first circle is approximately 40% of the diameter of the second circle throughout the depth of the hole 10.

[0053] The maximum radius of the hole 10 at the first face 2 is approximately 60% of the maximum radial distance of the outer perimeter (i.e. outermost extent) of the fastening device 1 from the axis 11. The maximum radius of the hole 10 at the second face 3 is approximately 30% of the maximum radial distance of the outer perimeter (i.e. outcrmost extent) of the fastening device 1 from the axis 11. The maximum radius of the hole 10 is preferably between 20% and 80% of the maximum radial distance of the outer perimeter (i.e. outermost extent) of the fastening device 1 from the axis 11, and more preferably between 30% and 60%.

[0054] The fastening device 1 is suitable for receiving a threaded member, as shown in figures 6a and 66.

[0055] In figure 6a, the threaded shaft 31 of a screw 30 is shown inserted into the hole 10 fastening device 1. The screw 30 is inserted into the entrance to the hole 10 adjacent the first face 2, and is rotated (as conventionally done when fixing a screw) into the hole so that the threaded shaft 31 grips the sides 14 of the hole 10 and converts rotational motion of the screw into linear motion to move the screw 30 through the depth of the hole 10. The threaded member interlocks with the fastening device 1 to lock the screw 30 into place.

[0056] The threaded shaft 31 of the screw 30 has a maximum diameter that is between the maximum diameter of the second circle adjacent the first face 2 and the minimum diameter of the second circle adjacent the second face 3. When the screw 30 is inserted into the hole, the threaded shaft 31 cuts and deforms the hole 10, forcing the cross-section of at least a portion of the hole 10 to yield to the shape of the threaded shaft 31.

[0057] As the area between the first and second circles of the hole 10 is partially filled, the material in this area is able to plastically deform into the unoccupied spaces in the hole 10 and conform to the thread shape of the screw 30. The fastening device therefore functions using combined cutting and deforming actions, wherein the deformation may be elastic and/or plastic deformations.

[0058] The advantage of the shape of the hole 10 is that a variety of different threaded members can he inserted into holes 10 of the same dimension, regardless of the thread shape and dimensions, as the material can be displaced into the empty spaces between the vertices so as to provide access to threaded members with a wide variety of fasteners.

[0059] This can he achieved without causing significant stresses that would otherwise crack/rupture the material, and without substantially changing the outer shape of the fastening device 1.

[0060] The function of the fastening device I is substantially the same when receiving a bolt as when receiving a screw, as shown in figure 6b, which shows the threaded shaft 41 of a bolt 40 inserted into the hole 10.

[0061] In this example the fastening device 1 can serve a similar purpose to a conventional nut, which is threaded onto a bolt such that multiple parts can be fastened together between the fastening device 1 and the head of the bolt. In an alternative example, the fastening device 1 can be used as a locking nut in addition to a standard threaded nut, and positioned adjacent to the threaded nut such that the nut is secured in position.

[0062] Figures 7a-7e show examples of the fastening device 1 having different numbers of vertices to the previous examples.

[0063] It will he clear to the skilled person that many of the features described in relation to each of the examples of figures 7a-7e can be appropriately combined with the features of the previous examples, and that features of the previous example can be appropriately combined with the features of the examples in figures 7a-7e. For instance, the taper of the hole 10 and cuboidal outer shape of the fastening device 1 shown in relation to the first example is applicable to each of the following examples.

[0064] Figure 7a shows an example in which similar reference numerals are used to denote similar parts but numbered in the 100 series.

[0065] The fastening device 101 has a hexagonal shaped outer perimeter defined by opposing third and fourth faces 104a,104b perpendicular to the first face 102, opposing fifth and sixth faces 105a,105b perpendicular to the first face 102, and opposing seventh and eight faces 106a,106b perpendicular to the first face 102.

[0066] The hole 110 has three first vertices 112, and three second vertices 113, and six substantially planar sides 114 between the adjacent first and second vertices 112,113.

[0067] Figure 7b shows an example in which similar reference numerals are used to denote similar parts but numbered in the 200 series.

[0068] In the example of figure 76, the fastening device 201 has a hexagonal shaped outer perimeter, as in the example of figure 7a, and a hole 210 having six first vertices 212 and six second vertices 213, and twelve sides 214 between the adjacent first and second vertices 212,213.

[0069] Figure 7c shows an example with similar reference numerals used to denote similar parts but numbered in the 300 series, in which the hole 310 has nine first vertices 312 and nine second vertices 313, as in the first example, and a hexagonal shaped outer perimeter, as in the examples of figures 7a and 7b.

[0070] Figure 7d shows an example in which similar reference numerals are used to denote similar parts but numbered in the 400 series. The hole 410 has eleven first vertices 412 and eleven second vertices 413, and twenty one sides 414 between the adjacent first and second vertices 412,413.

[0071] Figure 7c shows an example in which similar reference numerals are used to denote similar parts but numbered in the 500 series. The hole 510 has fifteen first vertices 512 and fifteen second vertices 513, and thirty sides 514 between the adjacent first and second vertices 512,513.

[0072] The fastening device 1 in each of the examples is preferably nylon, although may suitably be made of any appropriate plastic, such as ABS or epoxy. The fastening device 1 may alternatively be made from mild steel, or any other suitable type of metal. The fastening device 1 may alternatively be made of a suitable rubber, in which case the deformation of the hole 10 would be substantially elastic.

[0073] It will be clear to the skilled person that the examples described above may be adjusted in various ways. For example, the hole may have any suitable number of first and second vertices. The number of first vertices may not be the same as the number of second vertices. Any first vertex angle may be different from any other first vertex angle, and any second vertex angle may be different from any second vertex angle. The fastening device 1 may not include second vertices, such that the first vertices 112 are connected by non-planar sides 14.

[0074] The hole 10 may be tapered along only a portion of the hole depth, such that a portion of the sides 14 of the hole are parallel to the axis in a second portion of the hole. This may be in addition to the bevelled edges 15,16, or as an alternative.

[0075] Alternatively, the hole 10 may not be a through-hole, such that the hole terminates at a discrete depth within the fastening device 1.

[0076] The interior volume of the fastening device 1 may be a honeycomb structure, as in the first example. Alternatively the interior volume may be an expanded foam structure, or substantially solid, or other suitable construction.

[0077] It will be clear to the skilled person that many of the features described in relation to each example can be appropriately combined with the features of other examples. For instance, the taper of the hole shown in relation to the first example is applicable to each of the examples shown.

[0078] The hexagonal outer perimeter of the fastening device described in relation to the example of figure 7a may appropriately be applied to the example shown in figure 1. Alternatively the outer perimeter may be octagonal, or any suitable polygonal shape with any suitable number of sides.

[0079] Where the word 'or' appears this is to be construed to mean 'and/or' such that items referred to are not necessarily mutually exclusive and may be used in any appropriate combination.

l0080] Although the invention has been described above with reference to one or more preferred embodiments, it will he appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS1. A fastening device comprising: a body having a first face, a second face, and a third face, the second and third faces being perpendicular to the first face, and the third face being parallel to the second face, an axis normal to the first face, and a hole for receiving a threaded member,the hole extending into the body along the axis, wherein a cross section of the hole normal to the axis has a shape, the shape having at least 3 first vertices with interior angles greater than 1800.
2. A fastening device according to claim 1, wherein the shape has at least 6 straight sides.
3. A fastening device according to claim 1 or 2, wherein the shape has at least 3 second vertices with interior angles less than 180°.
4. A fastening device according to claim 3, wherein the shape has an equal number of first vertices and second vertices.
5. A fastening device according to claim 3 or 4, wherein the shape has an odd number of first vertices and an odd number of second vertices.
6. A fastening device according to any one of claims 3 to 5, wherein the first vertices are arranged along a first circle and/or the second vertices are arranged along a second circle.
7. A fastening device according to claim 6, wherein the second circle encircles the first circle, and a diameter of the first circle is at least 10% of a diameter of the second circle.
8. A fastening device according to claim 6 or 7, wherein a diameter of the first circle is no more than 95% of a diameter of the second circle.
9. A fastening device according to any one of claims 6 to 8, wherein the inner and outer circles are concentric about the axis.
10. A fastening device according to any of claims 3 to 9, wherein the first vertices are equiangularly arranged about the axis and/or the second vertices are equiangularly arranged about the axis.
11. A fastening device according to any of claims 3 to 10, wherein the first and second vertices alternate circumferentially.
12. A fastening device according to any preceding claim, wherein the first vertices have interior angles greater than 270°.
13. A fastening device according to any preceding claim, wherein the hole includes a bevelled edge adjacent the first face.
14. A fastening device according to any preceding claim, wherein the hole is tapered along the axis, optionally wherein the hole is tapered at 10° to the axis.
15. A fastening device according to any preceding claim, wherein the fastening device has a fourth face on an opposite side of the fastening device to the first face.
16. A fastening device according to claim 15, wherein the hole is a through-hole extending from the first face to the fourth face.
17. A fastening device according to any preceding claim, wherein a cross section of the body in a plane normal to the axis has a polygonal shape and the body is a polygonal prism.
18. A fastening device according to any preceding claim, wherein the outer shape of the body is substantially unchanged when a threaded member is resiliently received by the hole.
19. A fastening device according to any preceding claim, wherein the second and third faces are adjacent to the first face.
20. A fastening device according to any preceding claim, wherein a maximum radius of the hole is no more than 80% of the maximum radial distance of the outer perimeter from the axis.
21. A fastening device according to any preceding claim, wherein a maximum radius of the hole is no less than 20% of the maximum radial distance of the outer perimeter from the axis.
22. A fastening device according to any preceding claim, wherein the hole has a depth of at least 50% of a maximum radial distance of the hole from the axis.
23. A fastening device according to any preceding claim, wherein the fastening device is made of plastic, metal, or rubber, optionally wherein the fastening device is made of nylon.
24. A fastening device according to any preceding claim, wherein the fastening device is 3D printed.
25. A fastening device according to any preceding claim, wherein the fastening device has an interior volume formed from a foam or honeycomb structure. C) ATO