FIXING WASHER

Abstract

A fixing washer comprising: an outer portion and an inner portion, the outer portion is radially outward of the inner portion and the inner portion defines a recessed region which is arranged, in use, to receive a head of a fastener, and the washer also comprises a number of channels, each of said channels extends though the inner portion and the outer portion.

Claims

1. A fixing washer comprising: an outer portion and an inner portion, a junction portion which connects the inner portion to the outer portion, the outer portion is radially outward of the inner portion, and is of domed configuration, and the inner portion defines a recessed region which is arranged, in use, to receive a head of a fastener, and the washer also comprises a number of channels, each of said channels extends through the inner portion, the junction portion and the outer portion.

2. A fixing washer as claimed in claim 1 in which the channels extend aligned with a radius of the washer (at least in plan view).

3. A fixing washer as claimed in claim 1 or claim 2 in which the outer portion comprises a number of apertures.

4. A fixing washer as claimed in any preceding claim in which the inner portion comprises a countersink.

5. A fixing washer as claimed in any preceding claim in which the inner portion is of substantially frusto-conical shape.

6. A fixing washer as claimed in any preceding claim in which the outer portion is arranged to have resilient flexure.

7. A fixing washer as claimed in any preceding claim in which the outer portion is arranged to adopt a flatter shape or configuration in the in-use condition, as compared to the non-use condition.

8. A fixing washer as claimed in any preceding claim in which the washer comprises two opposing sides and in use, one side arranged to face a structure which the washer serves to secure the place and the opposite side arranged to face away from said structure.

9. A fixing washer as claimed in claim 4 in which the channels provided extend between neighbouring apertures.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various embodiments will now be described by way of example only, with reference to the following drawings in which:

[0029] FIG. 1 is a perspective view of a washer being a first embodiment of the invention,

[0030] FIG. 2 is a plan view of the washer of FIG. 1,

[0031] FIG. 3 is a side elevation of the washer of FIG. 1,

[0032] FIG. 4 is a radial cross-sectional of a fixer washer of a second embodiment of the invention,

[0033] FIG. 5 is a plan view of the fixer washer of FIG. 4 securing a backerboard to a host support structure, and

[0034] FIG. 6 is a cross-section of FIG. 5 on A-A.

DETAILED DESCRIPTION

[0035] There is now described a novel fixing washer 1, which is arranged to secure a backerboard, or similar, to a host support structure.

[0036] With reference initially to FIG. 1 the fixing washer 1 comprises an outer portion 2 and an inner portion 3.

[0037] The outer portion 2 is located radially outward of the inner portion 3, and surrounds the inner portion. The outer portion 2 is of generally domed shape. As will be described in more detail below, this is a sprung configuration which is of benefit when the fixing washer 1 is used to attach a backerboard to a host support structure

[0038] The outer portion 2 of the fixing washer is of generally annular shape and is provided with a number of through-holes, or apertures, 7, which are provided at equally angularly spaced locations, with their centres located on the same radial distance

[0039] The fixing washer 1 further comprises a junction region 4 which serves a transition between the inner portion 2 and the outer portion 3.

[0040] The inner portion 3 defines a recessed region 10 which is arranged, in use, to receive a head of a fastener. The recessed region 10 is of substantially frusto-conical shape. The inner portion defines an aperture centrally thereof which is arranged to receive the threaded shank of a fastener. The recessed region 10 may be described as a countersunk portion.

[0041] Reference is made to FIG. 3 which shows the fixing washer in side cross-section. The lowermost extent of the inner portion 2 can be seen to extend lower than the position of the outermost margin/periphery of the outer portion 3. (Similar remarks apply to the second embodiment which is described below.)

[0042] The fixing washer 1 also comprises a number of channels 5, and each of said channels extends though the inner portion 2 and the outer portion 3. The channels 5 are of curved transverse cross-section. The channels 5 are set into an outward side surface of the washer 1. The channels 5 are substantially aligned with a respective radius of the washer, when viewed in plan. The channels 5 extend from the outer portion 2 to the inner portion 3, though the junction region 4, in a substantially continuous and unbroken manner. In relation to the extent of the channels 5 in the outer portion 2, these run substantially centrally between successive apertures 7, and terminate prior to the circular periphery of the washer 1.

[0043] Reference is made to FIG. 3 which shows a side elevation of the fixer washer 1. The fixer washer 1 comprises two opposite sides, 14 and 15. The side 14 is intended to face outwardly when the washer is installed, whereas the side 15 is intended to face towards the backerboard which the fixing washer 1 is serving to secure in position to an underlying support structure.

[0044] FIG. 4 shows a fixer washer 100 compliant with a second embodiment of the invention. The fixer washer 100 is similar in many respects to the fixer washer 1, and like reference numerals are used or can be used to denote or characterise the same or very similar features.

[0045] One point of difference which the fixer washer 100 has over the fixer washer 1 is that the periphery of the washer (which is also the periphery of the outer portion), has a stepped/flanged formation, as shown at 60. In this, the radially outermost annular formation is set lower as compared to the major portion of the outer portion. This formation 60 contributes to the overall strength and rigidity and helps to prevent the washer from inverting (from concave to convex) if too high a torque force is applied to the fastener during installation. Although the formation 60 is shown in relation to the second embodiment, it is equally applicable and of benefit to the first embodiment.

[0046] A second point of difference is the channels 55, which unlike the channels 5 of first embodiment protrude/are raised. In this sense they may be termed ribs.

[0047] Reference is made to FIGS. 5 and 6 which show the fixer washer 100 in situ affixing a backerboard 150 to a support structure 200. This has been achieved by way of a screw fastener 300. A driving torque was applied to the keyed head 300a of the fastener with the threaded shank 300b extending through a central hole in the countersunk region of the inner portion. When the underside of the fastener head 300a bears against the inner portion, the washer 100 is forced against the backerboard 150. This urges the otherwise domed outer portion to flatten, countering the inherent spring force therein. As can be seen in FIG. 6, when the fastener is fully driven home to within the countersunk recess, the outer portion sits flat (or substantially so) against the backerboard. The sprung characteristic of the outer portion enhances the fixing strength of the backerboard to the underlying host support structure. The presence of the channels extending in both the outer portion and inner portion further enhances said fixing strength. In particular, the channels/ribs extending though both the outer portion and the inner portion enhance the strength of the washer and also increases the force needed to compress the (sprung) outer portion during use. The extent of the channels/ribs additionally helps with preventing inversion of the washer. Inversion (i.e. including concave to convex) of a fixing washer is undesirable since this obviates the functionality of the washer for its primary use. With reference to FIG. 6, it can be seen, and as described above, that the outer portion is flatten when the washer 1 is installed. In the absence of the channels/ribs as described there would be a risk that the washer could invert by turning inside itself, so that the outer portion would bow away from being in gripping engagement with the backerboard.

[0048] The above described extent of the ribs/channels also assists with the washer gripping the backerboard and preventing/inhibiting rotational forces during installation. These advantages are applicable to both the first and second embodiments.

[0049] It will be appreciated that although the first and second embodiments show respective numbers of apertures and channels/ribs, any other of one or each of those features could be used in variant embodiments.