BACKGROUND ART A_TD TECH-TICAL FIELD

This invention relates to fasteners and is concerned with fasteners for use in securing a member to an apertured wall structure. One form of the invention has particular application to fasteners as used in the electronic industry, wherein panel members are secured to apertured wall structures in the form of mounting flanges. Currently cage nuts are used by that industry, but such components have several defects. For example, they must be fitted from behind the mounting flanges•

Another form of the invention has application to fasteners serving as anchorages in. board materials used in the building industry, wherein, for example, hook-carrying members are secured to apertured wall structures of building board or in the form of hardboard-covered doors.

DISCLOSURE OF THE I_17E_TI0-

According to the invention, a fastener for use in securing a member to an aυertured wall structure, is characterised in that it is of resilient construction, and comprises two interengaging parts formed so that the fastener can be inserted en bloc in the wall structure aperture and also so that, by manipulation of the parts, the wall structure is secured between portions of said interengaging Darts.

In one form of the invention, the two interengaging parts comprise a bifurcated first part for receiving a member-securing screw, and a second part having a flange portion and lugs for engagement with the bifurcations of the first part. This arrangement is such that the fastener is inserted into the aperture with the bifurcations collapsed. Then, by causing the bifurcations to move apart so that they are gripped by the lugs, the wall structure is secured between the bifurcations of the first part and the flange of the second part. In another form of the invention, the two interengaging parts comprise a bifurcated first part and a second part for receiving a member-securing screw and for location within the bifurcations of the first part.

In this arrangement, the fastener is first inserted-into the aperture of the wall structure. Then, by insertion of the member- securing screw into the second part, the latter is caused to expand whereby the fastener is secured to the wall structure.

In a further form of the invention, the two interengaging parts comprise a bifurcated first part for receiving a member-securing screw, and a second part of tubular form having slots for slidable

location of the bifurcations of the first part.

In this arrangement, the fastener is first inserted into the aperture of the wall structure. Then, as before, by insertion of the member-securing screw into the second part, 5 ^" the latter is caused to expand whereby the fastener is secured to the wall structure. Slidable location of the bifurcations of the first part by the said slots ensures that the first part cannot rotate relative to the second part.

The invention also comprises the combination of a wall Q structure, (which may form part of a cabinet for housing electronic equipment, or, alternatively, it may comprise a door), and the fastener secured thereto.

The invention further comprises any novel subject matter or combination including novel subject matter herein disclosed. 5 ISF DΞBCRIFΓIOSΓ OF TH3 DRAWEES

3_π_bodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, wherein:-

Figure 1 is an "exploded" view of one form of fastener,

Figures 2, 3> 4 a 5 are side views illustrating how the Q fastener is secured in position,

Figures 6, 7» 8 and 9 are plan, front, rear and side views of the first part of the fastener,

Figures 10, 11 and 12 are plan, side and rear end views of the second part of the fastener. Figures 5 to 12 are all to an enlarged scale,

Figure 13 is an "exploded" view of one modified fastener,

Figure 14 is an "exploded" view of another modified fastener,

Figures 15 and 16 are views in perspective, looked at from opposite ends, of the fastener of Figure 14,

Figure 17 is an "exploded" view of a further modified fastener,

Figure 18 is a view in perspective of this fastener,

Figures 19, 20 and 21 are side views illustrating how this fastener is secured in position,

Figure 22 is an "exploded" view of another form of fastener,

Figures 25 and 24 are views in persDective of the assembled fastener of Figure 22, looked at fror. opposite ends,

Figures 25, 26 and 27 are plan views, illustrating how the fastener of Figure 22 is secured in position.

Figure 28 is an "excluded" view of yet another form of fastener, and

Figure 29 is an end view of the fastener of Figure 28, looked at in the direction of arrow A of that figure.

In the figures, like references refer to like components and features.

All the fasteners disclosed herein are of resilient construction and all may be made using injection moulding techniques. 3ΞST -10D3 OF CARRYING OUT TΞ5 I-T73-ΪTI0-T

The present disclosures describe and illustrate several embodiments of the invention.

With reference first to Figure 1, a fastener 1 for use in securing a panel member 2 (Figure 5) to an apertured wall structure 5> is of resilient construction and comprises interengaging first and second parts 3» .4. As will be apparent hereinafter, the parts 3, 4 are formed so that by manipulation of the parts, the wall structure 5 is secured between portions of the parts 3 _> 4«

The fastener 1 is of "- ^■ YLO-T 66", (Trade ____r_c), a sufficiently resilient material which can contain a fire resistant additive. A suitable alternative to ". LO.Ϊ 66 ⁿ is "-TCRYL" (S3-1 grade). ("ZTCRYL" is a Trade I_ar__).

As best seen in Figures 6 to 9 _. the first part 3 of the fastener 1 comprises a bifurcated block of substantially square lateral cross-section, having a head portion 3a. housing a screw- threaded insert 10

(Figure 3) which receives a panel member fixing screw 11 (Figure 5). The two jaw-like bifurcations 3.2. of the first part 3 define an elongated hollow 12 therebetween. The hollow 12, which is generally circular in lateral cross-section, provides a lead-in for the fixing screw 11.

The external sides of the bifurcations 3b. taper outwardly and away from the head portion 3a. Each side is formed with two recesses 13. Each recess 13 is bounded by end surfaces 14, 15 and an inner surface 16. The end surfaces 14 are of reduced depth, relative to the end surfaces 15, and, with the adjacent end surfaces 17 of the bifurcations, define walls or landings 18. v.ith particular reference to Figures 10 to 12, the second part 4 of the fastener 1 comprises a flange portion 4__ of substantially square shape, (viewed at one end), defining a central hole 20, and four hooks or lugs 4b_ disposed at the corners of an imaginary square. The hole 20 is sized to locate, with clearance, the fixing screw 11. ^τ .v ^r ith reference once more to Figure 1, the wall structure 5 of this example is a mounting flange of a cabinet (not shown) for housing electronic equipment. The wall structure 5 is perforated

by a row of substantially square-shaped apertures 25, each for reception of a fastener 1.

To install a fastener 1 in an aperture 25, parts 3 and 4 of the resilient fastener are assembled as illustrated in Figure 2, wherein the lugs 4b _, of part 4 are pushed or "snapped" over the landings 18 of part 3-

With reference to Figure 3> the interengaging assembly 3/4 is next pushed en bloc into the aperture 25. This action causes the jaw-like bifurcations 3b _, of the part 3 to collapse towards each other. In this condition, where the periphery of the aperture 25 serves to hold the bifurcations in their collapsed condition, the fastener 1 can easily be withdrawn from the aperture

25. The person installing the fastener may, for example, realise that it has been placed in the wrong aperture. It will be appreciated that the sloping (outer) sides of the bifurcations serve as ramps enabling a progressive lead-in of the fastener 1 into the aperture 25.

With reference to Figure 4» the fastener 1 is firmly installed in place by pushing the part 3 away from the part 4 until the bifurcations 3b _, of the part 3 are free of the restraint provided by

the aperture 25. The resilient bifurcations 3b. then move apart, to "snap" into position whereby the lugs 4b. grip the bifurcations 3b.so that the flange portion 4§_ and the end walls 18 are located together, in readiness to receive the fixing screw 11. The part 3 may be pushed away from the part 4 by use of a screwdriver for example, or, more likely, by inserting the securing screw 11, (Figure 5)> into the insert 10, via the aperture 20 of the part 4 and the lead-in hollow 12 of the part 3» after parting the collapsed bifurcations 3_.-> The screw 11 is then tightened, in order to secure the panel member 2 to the wall structure 5»

Use of a resilient cup washer 30 (Figure 5) between the head of the screw 11 and the panel member 2 is preferred.

Wnen the fastener 1 is secured in place, sloping sides of the bifurcations 3b, serve as struts, as they are subject to compressive forces imposed by the screw 11.

The bifurcations 3b. cannot now collapse inwardly, due to the presence of the screw 11 in the hollow 12 of the part 3» Further¬ more, the bifurcations 3b. cannot move apart. Such displacement is prevented by side contact between the bifurcations and the lugs 4b,

the lugs in turn being constrained by the periphery of the aperture 25.

The fastener 1, which may be used with a wide range of wall structure thicknesses, may be installed from the front of a wall structure 5 _. rather than from the rear thereof, as is demanded by the use of cage nuts.

In a non-illustrated modification, the material of the bifurcated part 3 is directly screw-threaded.

Figure 13 illustrates a modified fastener having :- (a) cut-away portions 35 of part 3> providing a more positive lead-in for the screw 11,

(b) a changed head portion 3a _, of part 3 _. to assist injection tool withdrawal, and

(c) a substantially rectangular, (preferably square), hole 3° ^" in the part 4 _. again for ease of injection tool design.

Figures 14 to lβ illustrate another modified fastener 101 intended for heavy duty use. The fastener 101 comprises inter¬ engaging first and second parts 103, 104.

The first part 103 comprises a bifurcated block of substantially square lateral cross-section, having a portion 103a _, and two jaw-like

bifurcations 103b _, defining an elongated hollow 112 therebetween- External opposite surfaces of the bifurcations 103b, are substantially parallel. Elongated gaps 150 exist between the bifurcations 103b.. The head portion 103a, carries a bifurcated end flange 152 separated by a gap 153 o smaller width then a gap 150.

The second part 104 is also bifurcated, comprising a body portion 155 defining bifurcations 155b_, a blind-ended central hole 120 for receiving a panel securing screw 111, and tapered fins or lugs 15.2 _* The hole 120 is formed with a female screw- thread. The body part 155 is of substantially circular lateral cross-section and is located by the hollow 112 of the first part 103.

To install the fastener 101 in a selected aperture, parts 103 and 104 of the fastener are first assembled as illustrated in Figures 15 and 16, and the interengaging assembly 103/104 pushed en bloc into the aperture. The portions of the bifurcated flange 152 part to allow entry of the part 104 into the part 103, on assembly.

As the fastener 101 is pushed en bloc through the selected aperture, the lugs 155c, collapse, to allow entry into the aperture.

Once the fastener is in position, the lugs 155c. are displaced outwardly, by resilience, to secure the fastener in place, by insertion of the securing screw 111 in the screwthreaded hole 120. As the screw 111 is tightened, the part 104 is drawn towards the flange 152. During this movement, the lugs 155c. are slidably located by the slots 150.

When the fastener 101 is secured in place, the sloping bifurcations 155 serve as struts, as they axe subject to compressive forces imposed by the screw 111. Unlike the fastener 1, the fastener 101, once assembled and inserted in place, cannot be removed, at least without damage.

With reference now to Figures 17 to 21, a fastener 201 for use in securing a panel member 202 (Figure 2l) to an apertured wall structure in the form of a plate member 205, comprises inter- engaging first and second parts 203, 204.

The first part 203 comprises a bifurcated block of substantially circular lateral cross-section, having a portion 203a. and two jaw¬ like bifurcations 203b _, defining an elongated hollow 212 there- between _β Scternal opposite surfaces of the bifurcations 203b_ are

substantially parallel. Elongated gaps 250 exist between the bifurcations 203b. The head portion 203a, carries a bifurcated flange 252 separated by a gap 253 of smaller width than a ^' gap 250. Anti-twist ribs 252 are formed adjacent the junction between the 5 head portion 203a _, and the bifurcations 203b..

The second part 204 is also bifurcated, comprising a body portion 255 defining bifurcations 255b. _. a central hole 220 for receiving a panel securing screw 211 and tapered fins or lugs 255_3.» The hole 220 is formed with a female screwthread.

ICC The body part 255 is of substantially circular lateral cross- section and is located by the hollow 212 of the first part 203. The slots 250 slidably locate the lugs 255c _, .

To install the fastener 201 in a circular aperture 225 formed in the structure 205, parts 203 and 204 of the fastener are

15 assembled as illustrated in Figures 18 and 19 and the inter¬ engaging resilient assembly 203/204 is pushed en bloc into the apertures 225 (Figure 20).

The portions of the bifurcated flan_:e 252 part to allow entry of the part 204 into the part 203, on assembly.

2 ^Q - As the fastener 201 is pushed en bloc through the aperture 225.

the lugs 255 collapse, to allow entry. Once the fastener 201 is in position, the lugs 255£ are displaced outwardly, by resilience.

With reference to Figure 21, 'the fastener 201 is used to secure an apertured cover member 202 to the structure 205 ^" by inserting the screw 211 into the hole 220 (Figure 17) of the second part 204. Entry of the screw 211 into the hole 220 causes the second part 204 to expand, behind the structure 205, which is then located between the lugs 255c. and the head portion 203a.. _ As before, when the fastener 201 is secured in place, the sloping bifurcations 255c. serve as struts, as they are subject to compressive forces imposed by the screw 211.

With reference now to Figures 22 to 27 _. a fastener 301 for use in securing a hook-like member 302 (Figures 2β and 27) to an apertured building board structure 305 serving as a wall, comprises interengaging first and second parts 303, 304• The member 30 is of "U"-shaped form, when viewed in the direction of arrow 300, wherein limb 300^ is secured to the structure 305 and limb 300b _, serves as a hook. The fastener 301 serves as an anchorage for the hook-like

member 302.

The first part 303 of the fastener 301 comprises a body 303_a of tubular form and of substantially circular lateral cross- section, with an external flange 353 at one end. The part 303 has a throughbore 312 and oppositely-disposed slots 350 are formed in the wall of body portion 303. of the part 303• The throughbore 31 is not of uniform cross-section. One end of the part 303 h s an inward flange portion 36O. Anti-twist ribs 352 are formed adjacent the junction between the flange 353 and the body 303a..

The second part 3040 f the fastener 301 is also bifurcated, comprising a tubular body portion 355 with a pair of bifurcations defining laterally-extending wing portions 355a _, and a pair of laterally-extending lug portions 355b _, . A central hole 320 for receiving a panel securing screw 311 extends through the body part 355» which is of substantially circular lateral cross-section.

To install the fastener 301 in an aperture 325 formed in the building board structure 305, parts 303 and 304 of the fastener are assembled as illustrated in Figures 23 and 24, that is to say with the part 304 disposed within the part 303 _, with the wing

portions 355a _, extending laterally through the slots 350, whereby they are slidably located. The length of each lug portion 355b_ is such that its outer ends are now substantially flush with the exterior surface of the body 303a.. The resilient nature of the parts 303» 304 allows this assembly.

The interengaging assembly 303/304 is next pushed en bloc into the aperture 35 (Figure 25). The flange 353 serves as a stop.

As the assembly 303/304 is pushed through the aperture 325, the resilient wing portions 355a _, collapse towards each other, to allow passage of the assembly.

With reference to Figures 26 and 27» the fastener 301 is used to secure the hook-like member 302 to the board structure 305 by inserting a screw 311 into the hole 320 of the second part 304. Entry of the screw 311 into the hole 320 first causes the part 304 to move away, until stopped by contact between the lugs 355b, and the ends of the slots 350. As the screw 311 is turned, the wing portions 355a are caused to move anart so as to extend through the slots 350 once again. This movement is caused by contact between the screw 311 and projections 3552_ _, » referred to below.

At the same time, the part 304 is drawn down, towards the board 305, until the board is firmly clamped between the wing portions 355a. and the flange 353, and the limb 300a of the hook member 300 clamped equally firmly between the flange 353 and the head of the screw 311•

The wing portions 355a _,. which are slidably located by the slots 350, are prevented from turning about the longitudinal axis of the screw 311, i.e. rotating relative to the part 303. as they are drawn towards the board structure, because contact with the tubular body 303SL prevents this. In turn, body 303a. is prevented from rotating by reason of the ribs 352, which dig into the yieldable material of the board 30 _*

The wing portions 355.a are formed with projections 355x, (Figure 27) sized to fit snugly into the hole 325 in the board structure 305 when the fastener 301 is secured in position.

When the fastener 301 is secured in place, the wing portions 355a, serve as struts, as they are subject to compressive forces imposed by the screw 3H«

To suit different thicknesses of building board material, as | well as equivalent wall structure material such as hardboard, a range of fasteners may be provided, each ^' fastener having a tubular part 301 of differing length.

Figures 28 and 29 illustrate a second part 404 which comprises a modification of the second part 304 of Figures 22 to 27 and can be substituted therefor.

The second part 404 has wing portions the inner 5 surfaces of which define convexities 480.

The "scallops" formed by the convexities 480 ensure that the point of the screw 411» (Figure 2B), is guided, after some initial tilting, into the hole 420. The dotted lines 411 of Figure 29 illustrate how the longitudinal axis 4Hx °f ^" the screw 10.. is initially tilted.

As the screw 411 is tightened, further contact between the screw and the "scallops" at first tends to force the wing portions 455a, apart, as in the case of wing portions 355a. of Figure 26. Thereafter, tightening of the screw 411 draws the part 404 down, 15 so that the wing portions 455a. exert a clamping force, as in the case of the wing portions 355a. of Figure 27.