EP0698165B1

EP0698165B1 - Improvements in or relating to backplates

Info

Publication number: EP0698165B1
Application number: EP94914514A
Authority: EP
Inventors: Reginald Howard Hall; Simon David Edward Mills
Original assignee: NT Architectural Hardware Ltd
Current assignee: NT Architectural Hardware Ltd
Priority date: 1993-05-15
Filing date: 1994-05-12
Publication date: 1997-10-08
Anticipated expiration: 2014-05-12
Also published as: DE69406133T2; EP0698165A1; GB9310059D0; WO1994027010A1; DE69406133D1

Abstract

A backplate (11) is secured at a surface (32) of a wing (19), such as a door, by the use of an insert (17; 46) which is itself secured by screws (22) passing into the wing, the insert being fitted in an aperture (16; 34) in the backplate with a collar (23; 39) fitted around its periphery, the collar engaging the insert and the backplate to prevent movement of the backplate away from the surface. The insert (17; 46) can be of various forms, such as a rose for mounting a rotatable lever handle (12) and the backplate can also have a further aperture (10; 35) for a further insert (14; 52), such as an escutcheon, which is also received in a collar (24; 39) which itself is secured to the backplate. The invention enables selected different inserts readily to be fitted to the backplate which is then automatically secured in place by the securement of an insert to the surface (32).

Description

This invention relates to backplates of the kind normally secured to a side of an angularly movable wing, such as a door, normally to mount a handle. At a position spaced from such mounting of the handle, there is often also an opening formed integrally in the backplate for operation of a lock of the door, in use.
Where a lock is used, it is known to fix hardware at one side of the door through or into the lock case, in particular when the hardware is a conventional rose. In contrast backplates are still fixed in place by screw fixings at their corners and have not used this bolting through to the lock case.
Document DE-U-8 421 176 shows a backplate assembly comprising a backplate having an aperture therein, an insert cooperating with said aperture and adapted to be fixed relative to a surface at which the backplate is to be secured, in use, and an element engageable with the insert, the arrangement being such that, in use, the element engages said insert and also engages the backplate.
An object of the invention is to provide improved means of securing a backplate at a surface of a wing, as well as an improved method thereof.
According to the present invention there is provided a backplate assembly comprising a backplate having an aperture therein, an insert receivable in said aperture and being adapted to be fixed relative to a surface at which the backplate is to be secured, in use, and an element engageable with at least part of the periphery of the insert, the arrangement being such that, in use, the insert is received into the aperture, said element engages with said at least part of the periphery of said insert and also engages the backplate to prevent movement of the backplate relative to the insert in one direction, the insert being fixed relative to the surface at which the backplate is to be secured to prevent movement of the backplate relative to the insert in the opposite direction, thereby securing the backplate at said surface.
According to a further aspect of the invention a method of securing a backplate at a surface comprises providing a backplate having an aperture therein, an insert receivable in said aperture and being adapted to be fixed relative to said surface, and an element engageable with at least part of the periphery of the insert, and carrying out the steps of engaging said element with said at least part of the periphery of the insert, before or after receiving said element into said aperture, said element with said insert engaged therewith engaging the backplate to prevent movement of the backplate relative to the insert in one direction, the insert being fixed relative to said surface to prevent movement of the backplate relative to the insert in the opposite direction, thereby to secure the backplate at said surface.
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

Figure 1 shows diagrammatically how different lock centres relate to a backplate,
Figures 2 and 3 schematically show how one insert of the backplate can be orientated in either of two positions respectively to accommodate either of two different lock centres;
Figure 4 is a front view of a backplate of the invention;
Figure 5 is a sectional side view of the backplate of Figure 4 showing a lever handle and spring cartridge unit carried at an insert in the form of a rose of the backplate;
Figure 6 is a section side view of the assembled rose, lever handle and spring unit prior to insertion into an aperture of the backplate;
Figures 7 to 9 are respectively a rear view, a sectional view on line A-A of Figure 7 and an enlarged scrap view of the circled part of Figure 8, of a rose fixing ring for the rose of the backplate of the invention;
Figures 10 to 13 are respectively a rear view, a front view, a sectional view on line B-B of Figure 10 and an enlarged scrap view of the circled part of Figure 12, of a fixing ring for the further insert of the backplate;
Figure 14 is a front view of a backplate of a further embodiment of the invention;
Figure 15 is a sectional side view on line C-C of Figure 14;
Figure 16 is an enlarged scrap view of the circled part of Figure 15;
Figures 17 and 18 are respective rear and front views of a fixing ring for use with the backplate of Figure 14;
Figures 19 and 20 are sectional views on the line D-D of Figure 17 and the line E-E of Figure 18 respectively;
Figure 21 is a plan view of the ring of Figures 17 and 18;
Figures 22 and 23 are enlarged scrap views of the circled parts of Figures 19 and 20 respectively;
Figures 24 and 25 are respectively a rear view and a front view of a rose insert for use with the backplate of Figure 14;
Figure 26 is a side view of the rose insert;
Figure 27 is a sectional view on the line F-F- of Figure 24;
Figure 28 is an enlarged scrap view of the circled part of Figure 27;
Figure 29 is a front view of an escutcheon insert for use with the backplate of Figure 14; and
Figure 30 is a sectional view on the line G-G of Figure 29.

The present invention is generally related to means of reducing the number of different backplates which a manufacturer must provide, whilst still being able to meet normal demand for a wide variety of such different plates. This is basically achieved either by providing in an aperture in the backplate a single insert which can be arranged in at least two alternative orientations, or by providing a variety of different inserts which can be fitted in said or another aperture provided in the backplate therefor. One of said variety of different inserts can be a rose on which a lever handle is intended to be mounted.
Figures 1 to 3 show a circular aperture 10 provided in a backplate 11 to accommodate different lock centres defined between an axis of rotation O of a lever handle 12 and a lock function spaced from said centre O along a vertical line 13 through the backplate. An insert in the form of a circular section disc 14 is received in the aperture 10, this disc having a configurated aperture 15 which matches the profile of a lock in a lock case in the wing to which the backplate is fitted, in use. The insert is thus in the form of an escutcheon.
Figures 1 to 3 show that the backplate has a further, identical circular aperture 16 vertically above the aperture 10. Both the aperture 10 and the aperture 16 are, in section, flat-sided. This is not, however, essential and for example the sides could be frusto-conical. With the arrangement shown in Figures 1 to 3, the insert 14 can be inserted into its aperture 10 in either of the two ways shown in full and dashed in Figure 1, and in Figures 2 and 3 respectively, so that the configurated aperture 15 is at a lock centre of either 57 mm (A) or 72 mm (B) from centre 0, so that depending upon the orientation of the disc 14, the backplate can be used in either its Figure 2 or Figure 3 configuration depending upon the lock centre of the lock used. Other discs can be provided to be fitted into aperture 10 as selected so as to provide the backplate with various different lock function apertures 15. All the various interchangeable discs may or may not have the facility for the rotation between two different orientations as shown in full in Figures 2 and 3. By this means the number of backplates required can be reduced greatly, so that, for example, a single backplate can be used for six or seven different types of lock purely by changing the form of insert 14.
With regard to the present invention, Figure 4 shows a backplate 11 in which is provided the circular apertures 10 and 16 as described, these being, in section, flat-sided. With this embodiment a rose 17 (also shown in Figure 1) in the form of a circular section plate is intended to be received in the aperture 16, the thickness of the rose being the same as or slightly less than the thickness of the backplate which is in the form of a rectangular flat plate approximately 3 mm in width. Preferably the plate is made of aluminium, brass or stainless steel, and the inserts are formed by stamping or punching out of the backplate. The resultant hole in the plate will then bored out to give the necessary accuracy and prevent distortion, resulting in virtually no material wastage. In the embodiment to be described, the rose 17 is thicker than insert 14.
As shown there is a suitably shaped hole 18 extending through the centre of the rose for a washer to mount a lever handle 12 so that it can be relatively angularly moved on the rose in the normal manner. The lever handle spigot would normally receive a spindle of conventional form, this spindle extending through the wing to operate a lock associated with a wing 19 in conventional manner. Additionally it can be seen from the Figures that a pair of screw fixing holes 20 are provided at opposite sides of the lever mounting hole 18 and the Figures show a spring cartridge unit 21 which would normally be mounted on the handle spigot for returning the handle to its horizontal rest position. The holes 20 receive fixing screws 22 which can pass through the unit 21.
This spring cartridge could, for example, be of the form generally shown in our U.K. Patent no. 2227518. Instead, however, of having a pair of spaced parallel compression springs, a single coil spring could be used.
Figures 5 and 6 show one of the fixing screws 22, and as mentioned, a pair of these would normally be received in the countersunk holes 20 in the rose 17, these screws being extended through to engage with pommels on a plate at a lock case if a handle is being mounted at one side of the wing only, or with corresponding screws extending from the opposite side of the wing if handles are to be mounted at both sides thereof. In this latter case some form of internally threaded, tubular connecting member would normally be used between the two sets of screws respectively. Finally it will be noted in relation to the backplate that there is a single fixing screw hole 22a at the bottom centre thereof (Figure 4). This however could be omitted in appropriate circumstances.
Figures 4 to 6 show that the rose 17 has fitted on its periphery, an annular fixing element or rose collar 23, whilst the insert 14 in aperture 10 has, fitted around its periphery, a peripheral collar 24. Each collar is of plastics material and is flexible.
The collar 23 is shown in detail in Figures 7 to 9. It can be seen that the collar has a cylindrical peripheral wall 25 from the respective opposite ends of which extend annular flanges 26, 27. The flange 26 is directed radially inwardly of the wall 25 whilst the flange 27 extends equally in a radial direction at opposite sides of the peripheral wall 25, the outer surface of the flange 27 being convex. The distance between the inner surface of the flange 26 and the inner surface of the part of the flange 27 which extends radially inwardly matches the thickness of the rose so that the collar can be snap fitted onto the rose by pushing the collar onto the rose in the direction of either the flange 26 or the inwardly directed part of the flange 27 until the rose is received between said flanges whereupon the deformed flange springs back so as to provide a firm assembly of the rose and collar. The distance from the inner surface of the outwardly directed part of flange 27 along the wall 25 to the opposite end thereof is substantially equal to the thickness of the backplate.
The collar 24 has a front flange 28 of very similar form to the flange 27 but differs in that at the rear of its cylindrical peripheral wall 29, instead of flange 26, it is provided with four, equi-angularly spaced flexible fingers 30 which mainly extend radially inwards, but which each have some extent radially outwardly to the same degree as the outwardly extending part of the flange 28, as best shown in Figure 14. Each finger has a certain width, and defines between its inner surface and the inner surface of the radially inwardly extending part of flange 28 a recess 31, having a width substantially equal to that of the insert 14. However the reduced thickness of the insert 14 compared to that of rose 17 is not shown in Figure 5 which is merely a general representation of how the insert disc 14 is fitted by way of its collar 24. It will be appreciated that the disc 14 can be snap-fittingly engaged in the recess 31 by deformation either of the inwardly directed part of flange 28 or, more preferably, by deformation of the fingers 30 which thereafter spring back to retain the disc in place.
Although the securing of the backplate at the surface 32 of the wing, such as a door, will now be described as incorporating retention of the disc 14 with its collar 24, it will be understand that the disc and collar could be omitted or could be retained in associated aperture 10 in a different manner. The invention, in this embodiment, relates to the securing of the backplate by means of the rose 17 or other form of insert together with its associated collar. Clearly it is not essential that the insert is in the form of a rose, in that it need not mount a lever handle or the like and thus need not have any central mounting aperture.
With the embodiment of the invention shown in Figures 4 to 6, the first stage in the preferred method of securing the backplate 11 at the surface 32 involves snap-fitting the collar 23 to the rose 17 to provide the arrangement shown in Figure 6 with the handle being rotatably mounted on the rose, via a washer, the associated spindle and spring unit also being present if desired. At this stage the screws 22 can be passed through the pair of holes 20 in the rose, although these could be inserted later as will be described. Additionally the collar 24 is passed into the aperture 10, preferably from the rear of the backplate, so that the outwardly directed part of the flange 28 is initially deformed and thereafter snaps back in place so that the collar is securely held against axial movement in its aperture 10 of the backplate, the collar 24 thus providing a fixing for the disc 14 and itself being fixed to the backplate. The disc 14 is then snap-fittingly engaged with the axially restrained collar by passing it into the collar past the fingers 30, from the rear of the backplate.
The backplate can then be correctly positioned against the surface 32 and the assembly shown in Figure 6 offered up to it. The collar 23 and rose 17 are thus received in the aperture 16 by passage inwardly from the front of the backplate until the outwardly extending part of flange 27 engages the outer surface of the backplate, as shown in Figure 5. The screws 22 are then passed through the holes 20, if not passed through previously, and screwed up to the lock case as described, or alternatively into the door surface. This retains the rose 17 against the surface 32, and by virtue of this and also due to the outwardly extending part of the flange 27 and flange 26, the backplate is held tight against the surface 32. As a result the disc 14 is similarly held in the backplate against removal, by virtue of the inwardly extending part of flange 28 and the outwardly extending parts of the fingers.
Finally, in order to prevent possible rotation of the backplate 11 about the rose a further fixing screw can be passed through the fixing hole 20 at the bottom of the backplate shown in Figure 4.
The backplate cannot now move in a direction away from the surface 32 as it is restrained by flange 27, nor in the opposite direction by virtue of the rose being fixed at surface 32 by the screws.
It will be appreciated that the collars need not be circular, it being sufficient that if continuous, they are complimentary to the peripheral shape of the rose and, if provided, the disc 14. However each of the 'collars' could instead be constituted by a single element engageable with only part of the periphery of the disc or rose, or with two or more separated peripheral parts. Moreover two or more separate elements could constitute the 'collar'. With some of these arrangements it may of course be disadvantageous that the apertures 10, 16 are not wholly concealed from view.
Instead of being of plastics material, the collars could alternatively be of metal. For the rose assembly the metal collar would be fixed, by mechanical means or by the use of adhesive(s), to the outer rim of the rose. For the insert discs 14 the metal collar would be fixed to the inside edge of the aperture in the plate. The rose would still be inserted from the front of the backplate and the insert preferably still from the rear.
If the rose is not circular and there is no possibility of rotation of the backplate 11, the lower fixing hole 20 can be omitted from the backplate so that the fixing is largely concealed and there is only one normally visible fixing hole. Thus a convenient and effective means and method of securing a backplate to a surface is provided. It will be appreciated that it is not necessary that the rose is screwed through to a lock case or the like, although this is preferred.
It will be appreciated that the inwardly extending part of flange 27 of flexible collar 23 could be omitted, in that it is the outwardly extending part of flange 27 and flange 26 which act to prevent movement of the backplate relative to the rose 17 in one direction, i.e. to prevent the movement of the backplate in a direction away from surface 32 in Figure 5, particularly if facility for a screw is not provided as at hole 22a. The fixing of rose 17 to the surface 32 prevents relative movement in the opposite direction, i.e. movement of the rose away from the surface 32 and backplate thereat.
Similarly with the backplate held at the surface 32 by the flexible collar 23 and rose 17, the collar 24 could have the inward extent of fingers 30 and/or the outwardly extending part of flange 28 omitted, and still prevent movement of the insert 14 in a direction away from the surface, and thus out of the backplate aperture 10.
In both cases however, initial assembly of the backplate, collars and inserts 14 and 17, would be less convenient than if the two collars are as in Figures 7 to 9 and 10 to 13 respectively.
A further embodiment of the invention will now be described in relation to Figures 14 to 30.
The backplate 33 is of similar form to backplate 11, having two circular apertures 34, 35 respectively therein disposed centrally of the plate, one above the other. The upper aperture 34 (with the backplate disposed as in Figure 14) is straight sided in section, but the lower aperture 35 has a section with only a short straight side 36, extending from the front face of the backplate, the remainder of the section of the aperture being angled outwardly and extending to the rear face of the backplate, so that the aperture is of greater diameter at the rear of the plate than at the front thereof. The rear part of the aperture thus has a frusto-conical surface 37.
The backplate is preferably of aluminium, brass or stainless steel and would, for example, be of 2mm thickness if of stainless steel and 3mm otherwise. As will be described the ring(s) and insert(s) to be used with the plate would be sized similarly according to the material selected. At its lower end is a countersunk fixing hole 38.
Instead of the use of two rings or collars 23, 24 as with the first embodiment, only a single ring is used in this embodiment, this ring 39 being metallic and preferably produced by pressure zinc die casting. As with the backplate the ring would be of aluminium or brass of a thickness to match the backplate thickness, or of stainless steel and of a lesser thickness to match the reduced thickness of the stainless steel backplate.
The ring has an annular front body part 40 with a convex front surface 41 and a flat rear surface 42. Extending normally from rear surface 42 at a position midway between its end is an annular wall 43. The length of this wall determines the variation in the ring thickness mentioned above depending on the material of the ring.
As best shown in Figures 19 and 20, the wall 43 is formed with eight cuts extending into it from its free end, the cut being equi-angularly spaced around the annular wall. One pair of diametrically opposite cuts 44 are wider than the remaining cuts 45, and extend to the rear surface 42. The cuts 45 terminate short of said surface. As will be described, the cuts 45 allow deformation of the material of the wall during crimping, whilst each of the cuts 44 can receive part of an insert to locate it in the ring.
Figures 24 to 28 show a rose insert 46 which replaces insert 17 of the first embodiment. The insert 46 is in the form of a flat plate of generally circular shape, but with its peripheral side surface 47 largely of frusto-conical form, the diameter of the insert decreasing from its front face 48 to its rear face 49. However like the interior surface 35, the surface 47 has a short straight section 47a. This is at the front of the insert. The insert is preferably made of aluminium, brass or stainless steel and its thickness, as mentioned, is varied depending on the material used, so that it can fit in the ring 39, which in turn can fit with the aperture 34.
The insert 46 has a radial extension ear 50 extending from its peripheral side surface, the ear extending for the full width of the insert and also having its outer surface frusto-conical. It is of a width, e.g. 10mm., to fit in either of the cuts 44. The insert has a central opening 51 therethrough which can be of any convenient shape to receive a lever handle or knob shank directly, or within a sleeve or other bearing received in the opening. In the example shown, the opening is generally star-shaped with rounded corners, to receive a washer. At diametrally opposite positions at respective opposite sides of the opening are countersunk screw fixing holes 51a.
Instead of the insert 14 in the first embodiment, there is now provided a profile cylinder or escutcheon insert 52. As with insert 46 it is metallic and its width is determined by the material used i.e. it is 2mm. thick if of stainless steel. The insert 52 has a peripheral side surface which is flat in section, but, like insert 52, has a radial extension ear 53 to fit in either one of the cuts 44. As shown in this example, a key-hole opening 54 extends through the insert, but other sizes/shapes of opening could be provided for different lock functions, or the inert could be without an opening and, for example, merely bear information. Of course the aperture 35 could be omitted from the backplate, or more than two apertures could be provided.
The order of assembly of the components which will now be described is preferable, but a different order of fitting together these components is also possible.
Firstly the rose insert 46 is received in a ring 39 with its front face 48 received against the part of surface 42 of the ring inwards of the wall 43. The wall 43 is then crimped onto the frusto-conical surface 47 of the insert so as tightly to secure the insert in the ring, the ear 50 of the insert being received in one of the cuts 44 to allow the insert initially to be held correctly in the ring. As mentioned, the cuts 45 allow the crimping.
Another of the rings 39 is fitted into the aperture 35 so that the front face of the backplate engages the part of surface 42 of the ring outwards of the wall 43. The wall is then crimped outwardly onto the frusto-conical surface 37 to retain the ring to the backplate.
The insert 52 can now be received into the ring fitted at aperture 35, with its ear 53 received in the upper one of the cuts 44 so that the key-hole opening 54 is correctly orientated, the insert being inserted from the rear of the backplate to engage the part of surface 42 inwards of wall 43.
The assembly of insert 46 and ring 39 crimped thereto is passed from the front of the backplate into aperture 34 until the part of the ring surface 42 outwards of the wall 43 engages the front surface of the backplate. The backplate is then offered up to the surface 32 of wing 19 and the insert 46 secured to the wing by screws passing through the holes 51a. The lever handle or knob can be engaged with the rose insert before or after it is inserted in the aperture 34.
The fixing of the insert 46 to the wing secures the backplate to the wing and thus also secures the insert 52 to the face of the wing, a screw passing through hole 38 into the surface 32 securing the bottom of the backplate against any movement away from the wing and preventing backplate rotation. The fixing is thus, as in the first embodiment, such as to prevent any relative movement between the rose insert and the backplate in either of two opposite direction, i.e. towards or away from the wing.

Claims

A backplate assembly comprising a backplate (11,33) having an aperture (16,34) therein, an insert (17,46) receivable in said aperture and being adapted to be fixed relative to a surface at which the backplate (11,33) is to be secured, in use, and an element (23,39) engageable with at least part of the periphery of the insert, the arrangement being such that, in use, the insert (17,46) is received into the aperture (16,34) said element (23,39) engages with said at least part of the periphery of said insert and also engages the backplate to prevent movement of the backplate (11,33) relative to the insert (17,46) in one direction, the insert being fixed relative to the surface at which the backplate is to be secured to prevent movement of the backplate relative to the insert in the opposite direction, thereby securing the backplate at said surface.
An assembly as claimed in Claim 1, wherein the insert (17,46) has front and rear faces and a side surface therebetween, and the element (23,39) has a front part engaging with a front surface of the backplate (11,33) in use, and a rear part thereof engaging with said side surface of the insert (17,46).
An assembly as claimed in Claim 2, wherein the element (39) is a continuous metallic collar.
An assembly as claimed in Claim 3, wherein the side surface of the insert (46) is at least partly frusto-conical, and the inner surface of the aperture (16,34) is straight sided in section.
An assembly as claimed in any one of Claims 2 to 4, wherein the rear part of the element (39) is deformed relatively inwardly onto the side surface of the insert (46).
An assembly as claimed in any one of Claims 1 to 5, wherein the insert (17,46) has at least one fixing hole (20, 51a) therethrough to secure it at said surface, in use.
An assembly as claimed in any one of Claims 1 to 6, wherein said insert (17, 46) has a central opening (18, 51) therethrough to allow the mounting at said insert, in use, of a latch operating handle (12).
An assembly as claimed in Claim 4, wherein a screw fixing hole (22a, 38) is provided in the backplate (11, 33) for a fixing screw, to prevent rotation of the backplate relative to the insert.
An assembly as claimed in any one of Claims 1 to 8, wherein the backplate (11, 33) has a further aperture (10, 35) therein in which is received, in use, a further insert (14, 52), with a further element (24, 39) being engaged with at least part of the backplate and with at least part of the further insert (14, 52), thereby to retain the further insert in the further aperture (10, 35) in the backplate secured at said surface.
An assembly as claimed in Claim 9, wherein the further element is identical with said element (39) and has a front part engaging with a front face of the insert (52), in use, and a rear part engaging with an interior side surface of the further aperture (35) in the backplate (33).
An assembly as claimed in Claim 10, wherein the interior side surface of the further aperture (35) in the backplate (33) is at least partly frusto-conical and the rear part of the further element (39) is of straight section.
An assembly as claimed in Claim 11, wherein the rear part of the further element (39) is deformed relatively outwardly onto the interior side surface of the further aperture (35).
An assembly as claimed in Claim 1, wherein said element (23, 39) is of flexible material.
An assembly as claimed in Claim 13, wherein said element (23, 39) is of plastics material.
An assembly as claimed in Claim 13, wherein said element (23, 39) is of metal.
An assembly as claimed in Claim 13 or Claim 14, wherein the insert (17, 46) is a snap-fit with the element (23, 39).
An assembly as claimed in any one of Claims 13 to 16, wherein the insert (17, 46) has at least one fixing hole (20, 51a) therethrough to secure it at said surface, in use.
An assembly as claimed in Claim 1, wherein a screw fixing hole (22a, 38) is provided in the backplate (11, 33) for a fixing screw, in use, to prevent rotation of the backplate relative to the insert (17, 46).
An assembly as claimed in any one of Claims 13 to 18, wherein the backplate (11, 33) has a further aperture (10, 35) therein in which is received, in use, a further insert (14, 52) with a further element (24, 39) engaged with at least part of the periphery of the further insert and also with said backplate, thereby to retain the insert in the aperture in the backplate secured at said surface.
An assembly as claimed in Claim 19, wherein said further insert is an escutcheon, which can be fitted in either of two alternative positions to vary the distance between lock centres defined at the two inserts respectively.
A method of securing a backplate (11, 33) at a surface comprising providing a backplate having an aperture (16, 34) therein, an insert (17, 46) receivable in said aperture and being adapted to be fixed relative to said surface, and an element (23, 39) engageable with at least part of the periphery of the insert, and carrying out the steps of engaging said element (23, 39) with said at least part of the periphery of the insert (17, 46), before or after receiving said element into said aperture (16, 34), said element with said insert engaged therewith engaging the backplate (11, 33) to prevent movement of the backplate relative to the insert in one direction, the insert being fixed relative to said surface to prevent movement of the backplate relative to the insert in the opposite direction, thereby to secure the backplate at said surface.
A method as claimed in Claim 21, wherein the element (23, 39) is a continuous metallic collar and the insert (17, 46) is firstly secured therein by inward crimping, the assembly of collar and insert then being inserted into said aperture in the backplate.
A method as claimed in either Claim 21 or Claim 22, in which a further insert (14, 52) is secured in a further aperture (10, 35) in the backplate, without said further insert being fixed to said surface.
A method as claimed in Claim 23, in which a further element (24, 39) is received in said further aperture (10, 35) being adapted to engage at least part of a front face of said further insert (14, 52).