GB2556869A

GB2556869A - Fixing element

Info

Publication number: GB2556869A
Application number: GB1616467.5A
Authority: GB
Inventors: Anthony Davidson Paul
Original assignee: Coupling Technology Ltd
Current assignee: Coupling Technology Ltd
Priority date: 2016-09-28
Filing date: 2016-09-28
Publication date: 2018-06-13
Also published as: GB201616467D0

Abstract

A fixing element suitable for a wall arrangement comprising a board 4 (e.g. a dry lined wall) comprises a tubular shaft 50 having an insertion end and a proximal end remote from the insertion end, in which a portion of the tubular shaft 50 adjacent the insertion end is formed with at least one pair of substantially longitudinal slots open at the insertion end and defining at least one fin 54 therebetween, and a tubular wedge 66 slideably and non-rotatably mounted within a portion of the tubular shaft 50 adjacent the insertion end. Drawing of the tubular wedge 66 towards the proximal end of the tubular shaft 50 causes the wedge 66 to move the or each fin 54 outwardly. The fin or fins 54 form a primary expansion zone. A portion of the tubular shaft 50 adjacent the proximal end is formed with at least one U-shaped slot, with the base of the U-shape facing away from the proximal end. The U-shaped slot defines at least one secondary fin 58, such that drawing of the tubular wedge 66 towards the proximal end of the tubular shaft 50 causes the wedge66 to move the or each secondary fin 58 outwardly. The tubular wedge 66 is provided with an internally threaded insert formed from a relatively harder material than the tubular wedge 66. In an alternative situation, the tubular wedge 66 is arranged to receive a threaded bolt such that a threaded portion of the bolt is arranged to protrude from the proximal end of the tubular shaft to receive a threaded nut.

Description

(54) Title ofthe Invention: Fixing element Abstract Title: Fixing element (57) A fixing element suitable for a wall arrangement comprising a board 4 (e.g. a dry lined wall) comprises a tubular shaft 50 having an insertion end and a proximal end remote from the insertion end, in which a portion ofthe tubular shaft 50 adjacent the insertion end is formed with at least one pair of substantially longitudinal slots open at the insertion end and defining at least one fin 54 therebetween, and a tubular wedge 66 slideably and non-rotatably mounted within a portion of the tubular shaft 50 adjacent the insertion end. Drawing of the tubular wedge 66 towards the proximal end of the tubular shaft 50 causes the wedge 66 to move the or each fin 54 outwardly. The fin or fins 54 form a primary expansion zone. A portion of the tubular shaft 50 adjacent the proximal end is formed with at least one U-shaped slot, with the base of the U-shape facing away from the proximal end. The U-shaped slot defines at least one secondary fin 58, such that drawing of the tubular wedge 66 towards the proximal end of the tubular shaft 50 causes the wedge66 to move the or each secondary fin 58 outwardly. The tubular wedge 66 is provided with an internally threaded insert formed from a relatively harder material than the tubular wedge 66. In an alternative situation, the tubular wedge 66 is arranged to receive a threaded bolt such that a threaded portion ofthe bolt is arranged to protrude from the proximal end of the tubular shaft to receive a threaded nut.

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FIXING ELEMENT

The present invention relates to a fixing element, in particular to a fixing element for a drywall board.

In modern construction buildings are formed with an underlying structure, such as walls (2), wooden frameworks and ceiling structures, for example a ceiling framework. The interior surfaces of the underlying structure, are then lined with board (4) so as to form a drywall optionally with a space or cavity between the board and the underlying structure. For example, the wall (2) might be constructed from thermal blocks or breeze blocks and the board (4) might be plaster board. In addition ceilings may be lined with such boards, in which case the boards are fixed to an underlying ceiling frame or substrate.

Drywall fixing elements are used to fix the board to the wall or other underlying structure. In addition fixing elements are used to fix various attachment elements such as brackets, for example for shelves or cupboards, or picture hooks, etc. to the board. As the board may not be strong enough to support such attachment elements when they are loaded, for example when they are supporting a shelf or cupboard, with items arranged on or within it, fixing elements are sometimes used which pass through the board and fix into the underlying structure.

According to the present invention there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

The invention will now be described by way of example only and with reference to the accompanying schematic drawings, wherein:

Figure 1 shows a longitudinal cross-section through a fixing element according to a first aspect of the present invention, having two expansion zones in an unfixed position;

Figure 2 shows a partial longitudinal cross-section of the fixing element of Figure 1 in a fixed position, extending between a section of board and an associated section of an underlying structure;

Figure 3 shows a longitudinal cross-section through a tubular shaft of the fixing element of Figure 2;

Figure 4 shows a side view of a tubular wedge of the fixing element of Figure

2;

Figure 5 shows a transverse cross-section through the tubular wedge of

Figure 4, taken at section AA of Figure 4;

Figure 6 shows a transverse cross-section through the tubular shaft of Figure 3, taken at section BB of Figure 3;

Figure 7 shows a transverse cross-section through the tubular shaft of Figure 3, taken at section CC of figure 11;

Figures 8a and 8b show longitudinal cross sections of a wedge according to a second aspect ofthe present invention; and

Figures 9a, 9b and 9c show views of alternative embodiments of the present invention.

Figures 1 to 7 show an embodiment of an extended fixing element according to an embodiment of the invention. It comprises two expansion zones, a primary expansion zone at the insertion end of the fixing element, for engaging an underlying structure (2), as shown in Figure 2 and a secondary expansion zone towards the proximal end of the fixing element, for engaging a section of board (4).

A tubular shaft (50) of the embodiment of Figures 1 to 7 is shown in longitudinal cross-section in Figure 3. The tubular shaft is formed with a radially outwardly extending collar (52) at its proximal end, for abutting a front face of a section of board (4), as is shown in Figure 2. At its insertion end the tubular shaft (50) is formed with four longitudinal slots, spaced equally around the circumference of the tubular shaft so as to define four primary fins (54) forming the primary expansion zone. At the end of the insertion end of the tubular shaft (50), the internal surface of the shaft is outwardly tapered from a diameter (D1) to a wider diameter at the end, forming a tapered transition surface (88).

Towards its proximal end the tubular shaft (50) is formed with two opposing Ushaped slots (56), defining two opposing secondary fins (58), forming the secondary expansion zone, as is shown in Figures 3 and 7.

The external surface of the tubular shaft (50) in the region of the primary and secondary expansion zones are formed with engaging elements in the form of a plurality of circumferential engaging ribs (60). A section on the tubular shaft (50) between the expansion zones is not formed with engaging elements.

The tubular shaft (50) has a first region adjacent the insertion end of the tubular shaft which has a substantially cylindrical internal cross-section D1 which extends along part of the primary fins (54). The shaft (50) has a second region, adjacent the first, which has an internal cross-section shown in Figure 6, which comprises two opposing part cylindrical sections (64) of diameter D1 separated by two opposing chord-sections (62) separated by a distance of D2. As shown in Figure 3, the chord-sections (62) are aligned with the regions between the secondary fins (58). The second region extends along the remainder of the primary fins (54) and along the central portion of the tubular shaft (50). The tubular shaft has a third region, adjacent the second, which extends along the secondary expansion zone and which has an internal cross-section shown in Figure 7 in which the cord-sections (62) continue into the region between the secondary fins (58) and in which the internal surfaces (90) of the secondary fins are part cylindrical with an internal diameter of D2, as is shown in Figure 7.

The tubular shaft (50) has a fourth region adjacent the proximal end of the tubular shaft which has a substantially cylindrical internal cross-section D3, for receiving a screw or bolt (70). The distance D3 is less than the distance D2 and the distance D2 is less than the distance D1.

The internal surface of the shaft (50) also comprises a first pair of opposing tapered transition surfaces (68) at its transition between the first region of diameter D1 and the chord-sections (62) of the second region. The internal surface of the shaft (50) further comprises a second pair of opposing tapered transition surfaces (84), as shown in Figure 1, at its transition between the part cylindrical regions (64) of diameter D1 of the second region of the tubular shaft and the part cylindrical regions (90) of diameter D2 of the third region.

The fixing element of the embodiment of Figures 1 to 7 comprises a tubular wedge (66) as shown in Figures 4 and 5. The tubular wedge (66) has a substantially cylindrical internal cross-section, as is shown in Figures 6 and 7, having diameter D3 and the internal surface of the tubular wedge is internally threaded for receiving a bolt or screw (70).

The tubular wedge (66) is formed at its insertion end with an increased first external diameter insertion end region (72) with a diameter D4 greater than D1. A proximal end region (74) of the tubular wedge (66) has a cross-section matching the internal cross-section of the central region of the tubular shaft (50), ie. two opposing part cylindrical surfaces (76) of diameter D1 in between two flat opposing chord-sections (78), spaced apart by distance D2, as shown in Figure 5. At the proximal end of the proximal end region of the tubular wedge, the part cylindrical surfaces (76) are formed with a proximal tapered transition surface (80) tapering from diameter D1 to diameter D2. The tubular wedge (66) is additionally formed with a tapered transition surface (82) between the insertion end region (72) and the proximal end region (74) of the wedge.

Figure 1 shows the fixing element of Figures 1 to 7 in an unfixed position. The fixing element comprises the tubular shaft (50) of Figures 3, 6 and 7, the tubular wedge (66) of Figures 4 and 5 and the screw or bolt (70).

The tubular wedge (66) is rotationally fixed within the tubular shaft (50) by virtue of the proximal end region (74) fitting non-rotationally in the second region (50) of the tubular shaft, ie. due to the engagement of the flat chord surfaces (62, 77) and the cylindrical surfaces (64, 76) (See Figures 6 and 7) of the internal surface of the central portion of the tubular shaft and the external surface of the proximal end portion of the wedge, respectively. In Figure 1, the tapered transition surface (80) at the proximal end of the wedge (66) abuts the tapered transition surface (84) at the insertion end of the secondary fins (58), between the second and third regions of the tubular shaft (50). Also, the tapered transition surface (82) between the insertion end region (72) and the proximal end region of the tubular wedge (66) abuts the tapered transition region (88) at the insertion end of the tubular shaft (50).

The screw or bolt (70) is externally threaded and passes through the fourth region at the proximal end of the tubular shaft (50) and is screwed into the internally threaded tubular wedge (66). An annular metal washer (90) is located between annular collar (52) at the proximal end of the tubular shaft and a head of the screw (70). The screw or bolt (70) may be made of metal.

A hole is drilled through a section of board (4) and into the underlying structure (4), just large enough for the fixing element, in its un-expanded state of Figure 1 to be fitted into the hole, with the annular collar (52) of the tubular shaft abutting a front face of the section of board.

Then the screw or bolt (70) is rotated, for example, using a screw driving device which engages the head of the screw (70) to drive it in rotation. The screw (70) is driven in a direction so as to cause the internally threaded tubular wedge (66) to move along the screw (70) towards the proximal end of the tubular shaft (50) and into the position shown in Figure 2.

In Figure 2, the abutting tapered transition surfaces (82,88) ride over each other as the tubular wedge (66) is forced by the rotation of the screw (70) (shown partly in dotted lines in Figure 2) to move towards the proximal end of the tubular shaft (50) so as to push the primary fins (54) outwardly to engage the sides of the hole drilled into the underlying structure (2), as shown in

Figure 2. Simultaneously, the abutting tapered transition surfaces (80, 84) ride over each other so as to push the secondary fins (58) outwardly to engage the sides of the hole drilled into the section of board (4), as shown in Figure 2. Figure 2 shows the fixing element in the fixed position, in which the circumferential ribs on the external surface of the primary and secondary fins, firmly engage the sides of the holes drilled in the underlying structure (2) and section of board (4) respectively. This, provides an effective load bearing fixing element.

Figures 8a and 8b show a disassembled and assembled cross-sectional view of an embodiment of the tubular wedge 166 which may be used in place of the tubular wedge 66 shown in Figure 4. It has been found that functionality and reliability are increased by means of the tubular wedge 166 which is essentially an adaptation of tubular wedge 66.

Tubular wedge 166 comprises many of the same features as wedge 66 described previously. In particular, it comprises a relatively elongate shaft 180, which is terminated with a proximal end region 170, which resembles closely the proximal end region 74, shown in Figure 5, of tubular wedge 66 and serves the same purpose, namely to fit non-rotationally in the second region (50) of the tubular shaft shown in figures 3, 6 and 7.

At an opposite end to the proximal end region 170, there is located an insertion end region 190 which serves essentially the same purpose as insertion end region 72 of the tubular wedge 66.

The insertion end region 190 is substantially uniformly tapered from a larger dimension at an extreme end towards a dimension matching the diameter of the elongate shaft 180 where the tapered region adjoins the elongate shaft. The purpose of the tapered region at the insertion end region 190 is to cause the fins 54 to be pushed outwards and so anchor the tubular shaft 50 in position in the wall 2.

Tubular wedge 166 differs to tubular wedge 66 in that it is provided with a threaded insert 200 which is provided to cooperate with the threaded bolt 70. The threaded insert 200 comprises an internally threaded barrel 220, from which extends perpendicularly a flange 210. The barrel 220 is inserted into the insertion end region and resides within the aperture provided therein, which is provided to accommodate the threaded bolt or screw 70. The flange 210 then abuts the flat end of the insertion end region 190 and ensures that when the threaded bolt 70 engages with the threaded insert 200, the tubular wedge 166 is drawn into the tubular shaft. In effect, the threaded insert replaces the internally threaded portion provided in tubular wedge 66.

The threaded insert 200 is preferably formed from a metallic substance suitably brass. It is further preferably provided with retaining means to ensure that it is firmly secured within tubular wedge 166. Such retaining means can take the form of circumferential ridges and/or transverse ridges, running lengthwise, to prevent the threaded insert rotating relative to the tubular wedge. The threaded insert can be inserted as a separate process following the moulding process used to produce the plastics material tubular wedge

166.

Figures 9a, 9b and 9c show a still further embodiment of the present invention.

Figure 9a shows a tubular wedge 266 of the same shape and profile as wedge 166 shown in Figure 8a. However, the operation of this device differs from that described previously. In the wedge 266, a captive bolt 270 is nonrotatably mounted inside the wedge such that the threaded end portion of the bolt extends from the proximal end region of the wedge. Once the wedge 266 is inserted in shaft 50 and then into the pre-drilled hole in the wall 2, the threaded end portion of the bolt 270 protrudes from the wall. Then, in order to secure the fastening formed from shaft 50 and wedge 266 in place, a nut (not shown) is affixed to bolt 270. By tightening the nut, the bolt 270 acts to draw the wedge 266 into the shaft 50, as has been described previously, and so secures the fastening in place.

The embodiment of Figure 9b differs slightly in that instead of using a captive bolt, a regular boly 370 may be used instead. It is simply inserted through the body of the wedge 366 so that the threaded end protrudes, as per the embodiment described previously in relation to Figure 9a. The bolt 370 may be provided with means to prevent rotation of it relative to the body of the wedge 366. This may be achieved by providing a cross-sectional area (e.g.

square) adjacent the head of the bolt to fit in a corresponding recess in the wedge.

The embodiment of Figure 9c uses a captive bolt, which is permanently embedded in the wedge 466 by being inserted into the moulded material while the plastics material is not fully solidified.

In all the embodiments of Figures 9a - 9c, the addition and tightening of a nut on the exposed threaded portion of the bolt causes the fixing element to be secured in place. The essential mechanism is effectively the same in all embodiments, namely that the tubular wedge element is drawn into the shaft 50, causing the fins 54 to expand outwards and secure the fixing element in place.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A fixing element suitable for a wall arrangement comprising a board, comprising:

a tubular shaft having an insertion end and a proximal end remote from the insertion end, in which a portion of the tubular shaft adjacent the insertion end is formed with at least one pair of substantially longitudinal slots open at the insertion end and defining at least one fin therebetween; and a tubular wedge slideably and non-rotatably mounted within a portion of the tubular shaft adjacent the insertion end;

wherein drawing of the tubular wedge towards the proximal end of the tubular shaft causes the wedge to move the or each fin outwardly, wherein the fin or fins form a primary expansion zone and a portion of the tubular shaft adjacent the proximal end is formed with at least one U-shaped slot, with the base of the U-shape facing away from the proximal end and wherein the U-shaped slot defines at least one secondary fin, such that drawing of the tubular wedge towards the proximal end of the tubular shaft causes the wedge to move the or each secondary fin outwardly and wherein the tubular wedge is provided with an internally threaded insert formed from a relatively harder material than the tubular wedge.

2. The fixing element of claim 1 wherein the internally threaded insert is formed from a metallic material, provided with at least one member projecting therefrom to inhibit removal or twisting of the insert.

3. The fixing element of claim 2 wherein the metallic material is brass.

4. A fixing element according to any preceding claim additionally comprising an externally threaded screw element inserted into the proximal end of the tubular shaft and engageable with the internal thread of the wedge so as to draw the tubular wedge towards the proximal end of the tubular shaft on rotation of the screw element.

5. A fixing element according to any preceding claim wherein a portion of the shaft adjacent the insertion end is formed with at least one slot and the wedge is formed with at least one projecting element slideably engageable with a corresponding slot.

6. A fixing element according to claim 5 wherein the projecting elements are slideably located within the open slots.

7. A fixing element according to any one of the preceding claims wherein at least a part of the external surface of the wedge tapers from a smaller diameter to a larger diameter in a direction towards the insertion end.

8. A fixing element according to any one of the preceding claims wherein at least a part of the internal surface of the tubular shaft adjacent the insertion end of the shaft tapers from a smaller diameter to a larger diameter towards the insertion end.

9. A fixing element according to any one of the preceding claims wherein the shaft comprises an outwardly extending collar at its proximal end.

10. A fixing element according to any one of the preceding claims wherein the shaft is made of a resilient material.

11. A fixing element according to any one of the preceding claims having an extended shaft wherein the length of the longitudinal slots is less than half of the length of the shaft.

12. A fixing element according to any preceding claim wherein the tubular wedge is formed with a first tapered transition surface on its external surface for engaging the fins and a with a second tapered transition surface on its external surface for engaging the secondary fins and the tapered transition surfaces taper from a smaller diameter to a larger diameter in a direction towards the insertion end.

13. A fixing element according to any preceding claim wherein the tubular shaft is formed with a third tapered transition surface on its internal surface for engaging a portion of the tubular wedge and with a fourth transition surface on its internal surface for engaging a portion of the tubular wedge and the third and fourth transition surfaces taper from a smaller diameter to a larger diameter towards the insertion end.

14. A fixing element according to claim 14 wherein the third tapered transition surface is located at the insertion end of the fins and the fourth tapered transition surface is located at the insertion end of the secondary fins.

15. A fixing element according to claim 13 or claim 14 when dependent on claim 12 wherein the first and third tapered transition surfaces engage and the second and fourth tapered transition surfaces engage to push the fins and the secondary fins outwardly.

16. A fixing element according to any one of the preceding claims additionally comprising at least one engaging element formed on the external surface of the tubular shaft.

17. A fixing element according to claim 16 when dependent on any ones of claims 11 to 15 wherein the engaging elements comprise a set of circumferential ribs in the regions of the fins and the secondary fins.

18. A fixing element according to any one of the preceding claims wherein the tubular wedge is rotationally fixed within the tubular shaft by virtue of a region of the internal surface of the tubular shaft having an irregular cross-section and a corresponding region of the external surface of the tubular wedge having a matching irregular cross-section.

19. A method of fixing a fixing element according to any preceding claim in a wall arrangement comprising a board and an underlying structure comprising the step of passing the fixing element through a hole in the board and locating the insertion end of the fixing element in a hole in the underlying structure and then drawing the wedge towards the proximal end of the shaft so as to cause the fins to move outwardly so as to engage the hole in the underlying structure.

20. A method of fixing a fixing element according to claim 18 to a board comprising the step of locating the fixing element in a hole in the board with the insertion end innermost and then drawing the wedge towards the proximal end of the shaft so as to cause the insertion end to move outwardly so as to engage the hole in the board.

21. A method of fixing a fixing element according to any one of claims 1 to 18 in a wall arrangement comprising a board and an underlying structure comprising the steps of passing the fixing element through a hole in the board and locating the insertion end of the fixing element in a hole in the underlying structure and then drawing the wedge towards the proximal end of the shaft so as to cause the fins to move outwardly so as to engage the hole in the underlying structure and the secondary fins to move outwardly so as to engage the hole in the board.

22. A fixing element suitable for a wall arrangement comprising a board, comprising:

wherein drawing of the tubular wedge towards the proximal end of the tubular shaft causes the wedge to move the or each fin outwardly, wherein the fin or fins form a primary expansion zone and a portion of the tubular shaft adjacent the proximal end is formed with at least one U-shaped slot, with the base of the U-shape facing away from the proximal end and wherein the U-shaped slot defines at least one secondary fin, such that drawing of the tubular wedge towards the proximal end of the tubular shaft causes the wedge to move the or each secondary fin outwardly, wherein the tubular wedge is arranged, in use, to receive a threaded bolt such that a threaded portion of the threaded bolt is arranged to protrude from the proximal end of the tubular shaft and the board to receive a threaded nut, whereby fastening the threaded nut to the threaded bolt causes the drawing of the tubular wedge towards the proximal end of the tubular shaft.

23. The fixing element of claim 22 further comprising a threaded bolt.

24. The fixing element of claim 23 wherein the threaded bolt is a captive bolt fastened securely inside or embedded within the tubular wedge.

25. A fixing element substantially as herein described and having particular reference to the attached drawings.

Intellectual

Property

Office

Application No: GB 1616467.5