This invention relates to a coupling.

In one aspect, the invention provides a coupling comprising first and second elements, the first element having first and second opposed portions at least one of which is resiliently deformable away from the other and which carry respective first and second surface formations, the second element having respective third and fourth portions which, in the assembled condition of the coupling, are engaged with the respective first and second formations to hold the two elements together, wherein said formations and third and fourth portions are so configured as to permit the elements to be assembled by first engaging said third portion with said first formation and then manipulating the second element whereby the fourth portion engages the second portion to cause relative outward displacement as between the first and second portions against resilient bias of at least one of the first and second portions to thence bring about a condition at which engagement between the first formation and third portion and between the second formation and fourth portion effects the holding of the elements together.

Preferably, the third and fourth portions and the first and second formations are so arranged that, as said elements are brought to said condition, force which is applied via the third and fourth portions to relatively outwardly displace the first and second portions is relieved at least partially to bring about relative inward movement of the first and second portions, under resilience thereof, to effect said holding. Thus, the engagement of the elements may occur as a snap action.

The second element may have opposed surfaces of the third and fourth portions formed as divergent surfaces

The first formation and third portion may comprise cooperating surfaces such that the movement of the second element required to bring about holding engagement between the elements following engagement of the first formation and third portion

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is at least substantially a relative rotational movement. The first formation may thus have a concave surface and the third portion a convex surface. Alternatively, the third portion may have a concave surface and the first formation have a convex surface. In any event, these surfaces may be generally arcuate. Likewise, the second formation and fourth portion may have cooperating surfaces of which one is convex and the other concave, such as one or both being generally arcuate. These cooperating surfaces may however be generally linear and arranged to lie against each other in the assembled condition of the coupling.

The first element may comprise an elongate strip with the first and second portions being in the form of opposed flanges extending lengthwise of the strip. The third and fourth portions may be somewhat elongate so as to extend lengthwise of the first element when the two elements are engaged.

Flanges defining the first and second portions of the first element may extend towards each other from opposed edges of a lengthwise extending web portion of the first element. The first and second portions may be defined at free ends of the flanges. In one form of the invention the flanges have respective root portions which extend away from the respective edges of the web portion and towards each other and the first and second portions extend one from each root portion back towards the web portion. In this case, the first and second portions may each have respective first and second divergent parts extending from the root portions to respective first and second convergent parts extending from the divergent parts to free ends of the respective first and second portions.

The invention also provides a holding device having a pair of arms extending from a portion thereof and thence, at side by side parts thereof, back towards the portion, the arms being formed of resilient material whereby to be able to grip an article positioned between and engaged by the arm parts.

The invention is further described by way of example only, with reference to the accompany drawings, in which:

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Figure 1 is a perspective view of elements of a coupling constructed in accordance with the invention;

Figure 2 is an end view of elements of the coupling shown in Figure 1, illustrating a first step of assembly of these together; Figure 3 is a view like Figure 2, but illustrating a subsequent step in assembly of the elements of the coupling;

Figure 4 is a view like Figure 2 but showing the elements of the coupling assembled;

Figures 5 and 6 are respective front and rear views of a second element of the coupling of the Figure 1;

Figure 7 is a perspective view of an alternative form of coupling constructed in accordance with the invention;

Figures 8 and 9 are end views showing steps in the assembly of coupling elements to form the coupling of Figure 7; Figure 10 is a perspective view of elements of a further form of coupling constructed in accordance with the invention;

Figure 11 is an end view of elements of the coupling of Figure 10 illustrating a first step in assembly of these together;

Figure 12 is a view like Figure 11, but showing the elements of the coupling of Figure 10 assembled;

Figure 13 is a rear view of a second element of the coupling of Figure 10; Figure 14 is a front view of the second element of the coupling of Figure 10; Figure 15 is an end view of the first element of the coupling of Figure 10; Figure 16 is an end view of elements of a further coupling constructed in accordance with the invention at positions adopted at the beginning of assembly of these together,

Figure 17 is an end view of the elements shown in Figure 16, in the coupled condition;

Figure 18 is a perspective view of the elements of Figures 16 and 17 coupled together,

Figure 19 is a rear perspective view of one of the elements shown in Figure 16;

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Figure 20 is a vertical cross section of a further form of second coupling element;

Figure 21 is a vertical cross section of a coupling element of the invention, formed as an open ended container; and Figure 22 is a side view of a shelf unit incorporating a first coupling element.

In Figure 1, the coupling 10 shown includes a first element 12 and a second element 14. Element 12 is in the form of an elongate channel-like strip having an elongate web portion 16 and opposed first and second flange-like portions 18, 20 which, as shown, extend somewhat inwardly towards each other from ends thereof, which connect with the web 16, to the free end edges thereof. The element 12 may be formed from plastics and is, in any event, arranged so that the free ends of portions 18, 20 are resiliently outwardly deformable one relative to the other.

The element 12 is designed to be affixed, such as by use of screws extending through apertures 22 in the web portion 16, so as to extend for example horizontally along an upright surface. Figure 2 shows such affixment by use of a screw 28 to attach the element 12 to an upstanding wall 30 so that the element 12 extends generally horizontally.

The element 14 is, in this case, designed to be coupled to element 12 so as to serve as a hook for articles such as household utensils or the like. It comprises a generally laminar body portion 32 having an upwardly hooked lower end portion 34 at the front thereof. On the rear face of portion 32, at an upper end of the portion 32, there is formed a transverse bead 36. Also on this face is a projecting web 38. Element 14 may be formed of plastics for example.

Bead 36 defines respective opposed third and fourth portions 42, 44 extending therealong at respective upper and lower edges of the bead as shown in the drawings. Portions 42, 44 are engageable with respective ones of first and second surface formations 48, 50 on inner surfaces of the portions 18, 20 of element 12, to hold the two elements together by a snap fitting action. The formations 48 and 50 are, in this

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case, generally concave and generally arcuate, and similarly the outer surfaces forming the portions 42, 44 on bead 36 are convexly arcuate and of complementary form to the surfaces defining formations 48 and 50. The spacing "X" between the opposed ends of the bead 36 at respective portions 42, 44 is slightly greater than the spacing "Y" between the surfaces defining formations 48 and 50 at the points of maximum separation of those surfaces.

To assemble the two elements 12, 14 together, the steps shown in Figures 2 to 4 are followed. Firstly, the element 14 is positioned as shown in Figure 2 with portion 42 received in formation 48 and with portion 44 adjacent to but immediately outside the formation 50. Because of the aforementioned greater spacing "X" between the portions 42, 44 as compared to the spacing "Y" between the formations 48, 50, the bead 36 as a whole will not at this stage fit between the formations 48, 50. However, by swinging of the element 14 as shown in Figure, such as substantially about a common axis of the engaged surfaces of formation 48 and portion 42 (in the clockwise direction as viewed), the portion 44 can be brought to bear against the outer edge of portion 20 to deflect the outer end of portion 20 downwardly against the natural resilient bias thereof, and or to deflect the outer end of the portion 18 upwardly to some extend against natural resilient bias thereof, to increase the separation of the formations 48, 50, whereas to permit the portion 44 to be brought into engagement with formation 50. This action occurs as of camming action of the portion 44 against the free outer edge of the portion 20. Thus, the condition of Figure 4 is then brought about where the element 14 is held to the element 12 by capturing engagement of the portion 42 with the formation 48 and by capturing engagement of the portion 44 with the formation 50.

In moving from the condition of Figure 3 to that of Figure 4, a kind of over centre action may occur, where the portions 18, 20 are permitted to move inwardly towards each other to some extent under natural resilience thereof as the condition of Figure 4 is reached while, however, still ensuring that the formations 48, 50 resiliently bear against the portions 42, 44 to effect secure holding.

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In the assembled condition, the web 38 may project rearwardly from portion 32 of element 14 towards the wall 30 so as to be closely adjacent thereto. That is to say, that the dimension "W" by which the web 38 extends from the rear face portion 32 of the element 14 may be made substantially equal to (such as just less than) the dimension "Z" shown, which represents the relative horizontal displacement between the portion 32 and the wall 30 when the elements 12, 14 are assembled together.

The described arrangement has been found particularly satisfactory in the described application. For example, substantial weights attached to the element 14 at the hook portion 34 cause pressing downwardly of bead 36 against the upwardly inclined portion 20 whereby the portion 20 exerts a substantial resistance to downward movement and to freeing of the coupling as between the elements 12 and 14. The more sharply upwardly inclined the portion 20 is, the greater will be this resistance. Preferably, the angle between web 16 and portion 20 is less than 50°, such as 45° or 30°. Furthermore, to the extent that there may be a tendency of the lower part of the element 14 to rotate in a clockwise direction as shown in Figure 4, to free the coupling by release of engagement between formation 48 and portion 42, this movement is resisted by engagement of the web 38 with the wall 30. Additionally or alternatively, such tendency to rotational movement could be resisted by arranging that the outer edge of portion 20 is brought into engagement or at least into close proximity with the immediately adjacent surface laminar portion 32 of element 14 when the elements 12, 14 are assembled.

Whilst quite considerable weights may, as mentioned, be attached to the element 14 without bringing about freeing of the elements, it is nonetheless a simple matter to release the coupling and free the element 14 from the element 12 by upward and outward swinging of the lower end of the element 14 to reverse the steps shown in Figures 2 to 4.

In the described arrangement, the formation 48 is described as having an arcuate surface of complementary form to the arcuate surface on the portion 42, and the formation 50 is similarly arcuately formed and of complementary form to that on

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the portion 44. It is not essential, however, that these formations and portions be so arranged. For example, one or both of the formations 48, 50 may define a generally V-shaped surface when viewed in section transverse to the direction of extent of the element 12. It has been found preferable that the surfaces defining portions 42, 44 should be generally rounded however. In any event, it is of course possible to arrange the elements so that the either or both formations 48, 50 are, instead of being generally concave as shown, generally convex, and so that either or both the surfaces of the portions 42, 44, have concave surfaces to engage the formations 48, 50, instead of these being convex as shown.

The invention has been described particularly in the context of an arrangement for providing support for a hook element, but of course various other types of elements could be attached to the element 12, such as shelves or the like. Also, the bead 36 could be formed on an elongate strip designed to form a closure to the channel section formed by the element 12. Thus, for example, if a number of items such as shelves, hooks or the like were assembled to the element 12 at spaced locations therealong, the spaces between these along the length of element 12 and between the free ends of portions 18, 20 could be fitted with such strip like elements for neatness of appearance.

Figure 7 illustrates an alternative form of coupling 110 constructed in accordance with the invention. This comprises first and second elements 112, 114. Element 112 is in the form of an elongate channel like strip having an elongate web portion 116 and opposed first and second flange like portions 118, 120. The portions 118, 120 extend inwardly towards each other from opposed edges of the web portion 116, in similar manner to the arrangement of the element 12 previously described.

The element 114 is again designed to couple to element 112, so as to serve as a hook. Element 114 comprises a plastics moulding having a planar side wall 114a which joins with an edge wall portion 114b, the wall 114a being designed, so that when the element 114 is attached to the element 112, the wall 114a extends generally normally to the direction of extent of the element 112 while portion 114b extends

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gencrally parallel to that direction. Wall portion 114b is configured so as to extend somewhat downwardly from a bead 136, thence upwardly to form an end portion 115 and thence downwardly at an angle as shown so as to form a hook. Bead 136 has opposed respective third and fourth portions 142, 144 which are engageable with respective first and second surface formations 148, 150 on the ends of flange like portions 118, 120 of element 112.

Aside from the particular physical form of the element 114 and the particular form of the portions 118, 120 of element 112, the coupling 110 is generally similar to the coupling 10 previously described. In particular, the action of assembly of the two elements together is illustrated in Figures 8 and 9 where the portion 142 and formation 148 are first brought into engagement (Figure 8) and then, under swinging action of the element 114, the portion 144 and formation 150 are brought into engagement under outward resilient deformation of the flange like portions 118, 120. In the final position shown in Figure 9, further rotation of the element 114 in the clockwise direction as viewed is again limited by engagement of the element 114 with a wall or the like to which the element 112 is affixed.

In the particular arrangement of Figure 7, the portions 142, 144 and surface formations 148, 150 are of somewhat more complex form than in the previously described arrangement. Thus, the portions 142, 144 exhibit in cross-section, such as shown in Figures 8 and 9, a sinuous form, having a concave trailing part 142a and a convex leading part 142b, portion 144 being similarly formed with a concave trailing part 144a and a convex leading part 144b. Formations 148, 150 define sinuous surfaces with formation 148 having a concave trailing surface part 148b and a convex leading surface part 148a. Similarly, formation 150 has a convex trailing surface part

150b and a convex leading surface part 150a. Formations 148, 150 may also have convex innermost surface parts 148c, 150c as shown. The parts of the sinuous surfaces of formations 148, 150 and portions 142, 144 are generally semicircular in cross-section, and arranged so that, on the initial engagement between formation 148 and portion 142, the surface part 148a is accommodated within surface part 142a and, as swinging occurs to the Figure 9 position, the surface part 142b is brought also into

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received engagement with the surface part 148b. The engagement between the formation 150 and the portion 144 which occurs under such assembly is first between surface part 144b and surface part 150a, to produce the required camming action to spread out the gap between the formations 148, 150 while in the fully assembled position, surface part 144b is accommodated within surface part 150b and surface part 144a accommodates surface part 150a as shown.

It has been found that forming the portions 142, 144 and formations 148, 150 in this fashion facilitates assembly. The surface parts 148c, 150c of formations 148, 150 are not essential, but help in providing a secure arrangement.

The coupling 210 shown in Figure 10 includes a first element 212 and a second element 214. Element 212 is in the form of an elongate channel-like strip having an elongate web portion 216 and opposed first and second flanges 215, 217, which, as shown, extend somewhat inwardly towards each other, from edges which connect with the web portion 216, and thence extend reversely back towards the web portion 216 to terminate a short distance therefrom.

The flanges 215, 217 have respective parts 219, 221 which are of arcuate cross-sectional form and which join with the web portion 216, and respective portions 218, 220 which extend from the free edges of the respective parts 219, 221 towards the web portion 216. The portions 218, 220 are in spaced opposed relationship with a gap therebetween. The portions 218 and 220 comprise respective first parts 223, 225 adjoining respective parts 219, 221 respectively, and free end parts 227, 229. Parts 223, 225 diverge somewhat in the direction towards web portion 216, from the locations where they join with the parts 219, 221. The parts 227, 229 are somewhat arcuate in cross-section and extend inwardly toward each other when viewed in section.

First and second surface formations 248, 250 are defined by the respective flange portions 218, 220, these surface formations being opposed to each other and each including a part 218a, 220a which is linear when viewed in cross-section,

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- 10 - defined at the respective parts 223, 225, and a respective convexly arcuate part 218b, 220b defined at the parts of 227, 229 of flange portions 218, 220.

The element 212 is formed of plastics material having some resilience, particularly permitting the free end parts 227, 229 to be resiliently deformed away from each other.

The element 214 is designed to be coupled to element 212 so as to serve as a hook for articles. It comprises a generally laminar body portion 232 having an upwardly hooked lower end portion 234 at the front thereof. At the rear of portion

232 there is a projecting web 238. At the upper end, portion 232 has an angled part

232a, in this case rearwardly angled at about 45° to the remainder of portion 232.

On the rear of part 232a there is formed a bead 236 which extends in the transverse direction of the part 232a. Viewed in cross-section, bead 236 has opposed portions 236a, 236b. Portion 236b has a surface formation 237 which has a corner 241 and a generally linear surface part 243, when viewed in transverse section, and portion 236a defines a surface formation 239 which is arcuate when viewed in transverse section.

In use, the element 212 may be secured for example to a wall 230 by screws or the like (not shown), so as to extend horizontally. To assemble the two elements 212, 214 together, steps as shown in Figures 11 and 12 are followed. Firstly, however, the element 214 is moved so as to enter the bead 236 into the gap between the flange portions 218 and 220, so that the portion 236a engages in abutting relationship with the surface formation 248 of the flange 215 which is, as shown, uppermost of the two flanges 215, 217. In this regard, the arcuate curvature of the formation 248 at surface part 218b is arranged to match the arcuate configuration of the surface formation 239 of bead 236. Following this movement, the element 214 is swung downwardly as shown in Figure 11 so that the bead portion 236b engages the flange part 225. More particularly, the corner 241 of the surface formation strikes the linear surface part 220a of the surface formation 250. Then, as further downward

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swinging occurs, the clement 214 swings as shown, the surface formations 248 and 239 pivoting about each other in the manner of a hinge. At the same time, during this action, the flange portions 218, 220 arc first forced apart against natural resilience thereof, with the corner 241 sliding along the surface part 220a. Then, as the element 214 is brought to a closed upright position as shown in Figure 12, the linear surface part 243 on bead 236 is brought flat against linear surface part 220a.

Some over-centre action may occur in bringing the element to the position of Figure 12. In particular, the dimension "X" in Figure 11 is the end to end dimension of the bead 236 represented between principal points of contact with the flange portions 218, 220 at the beginning of rotational movement of the element 214 to bring about coupling together of the elements. In Figure 15, Υ" is the rest dimension between the flange portions 218, 220, measured normal to the surface part 220a of flange portion 220 and to the arcuate surface part 218b of the surface formation of the other flange portion 218. The dimension "Z" measured at right angles from surface part 239 or bead 236 in the assembled condition, to the point of maximum extent of bead portion 236a away therefrom, is shown as "Z" in Figure 12. The dimension "Z" is slightly greater than the dimension Υ" so that resilient bias is applied by the flange portions 218, 220 to the bead 236 in the assembled condition of the coupling. The dimension "X" and the relative slope "α" of the surface 220a are such that, during initial movement of the element 214 to effect assembly, the camming action as between the bead 236 and the flanges portions 218, 220 at first is effective to progressively force the flange portions 218, 220 away from each other until a maximum point is reached shortly before the final position of Figure 12, after which the outward separation forces are slightly relieved as mentioned.

As shown, in this case too, the web portion 238 of element 214 is dimensioned so as to prevent further rotational movement beyond the position shown in Figure 12, so as to provide for secure alignment of the element 214 in the assembled condition.

This arrangement has been found to be particularly satisfactory because the linear surface part 243 and the cooperating surface part 220a, when engaged provide

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a very firm, near horizontal, bearing surface as between the bead and the flange portion 220 to prevent downward movement of the element 214 and disengagement from the element 212.

In the arrangement of Figures 10 to 15, the flanges 215, 217 are of identical mirror image form. This is convenient, since it permits the element 212 to be positioned to extend horizontally whether flange 215 or flange 217 be positioned uppermost. However, it will be appreciated that separate parts of the surface formations 248, 250 are brought into operation as concerns the interengagement with respective portions 236a, 236b of the bead 236. In particular, the form of the part 223 of flange portion 218 is hardly relevant to the function of the coupling and need not, for example, be linear as shown. Likewise, the surface part 220a as defined on surface formation 250 is the only surface part of that formation which necessarily interacts with the bead 236 as shown, so that the part 229 of the flange portion 220 may be of form other than shown, or omitted. In a modification, however, the shape of the surface formation 237 (and of bead portion 236b) is modified so that in the condition shown in Figure 12, this formation lies flush against the arcuate end portion 229, to assist in limiting the rotational movement of the element 214 relative to element 212, to the position shown in Figure 12.

The coupling 310 shown in Figures 16 to 19 includes a first element 312 and a second element 314. Element 312 is in the form of an elongate channel-like strip having an elongate web portion 316 and opposed first and second flanges 315, 317, which, as shown, extend somewhat inwardly towards each other, from edges which connect with the web portion 316, and thence extend reversely back towards the web portion 316 to terminate a short distance therefrom.

The flanges 315, 317 have respective parts 319, 321 which are of arcuate cross-sectional form and which join with the web portion 316, and respective portions 318, 320 which extend from the free edges of the respective parts 319, 321 towards the web portion 316. The portions 318, 320 are in spaced opposed relationship with a gap therebetween. The portions 318, 320 comprise respective first parts 323, 325

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adjoining respective parts 319, 321 respectively and free end parts 327, 329. Parts 323, 325 diverge somewhat in the direction towards web portion 316, from the locations where they join with the parts 319, 321. The parts 327, 329 are somewhat arcuate in cross-section and extend inwardly toward each other when viewed in section.

First and second surface formations 348, 350 are defined by the respective flange parts 323, 325, and respective adjacent sections of the flange parts 319, 321, these surface formations being opposed to each other and each including a part, 348a, 350a, which is linear when viewed in cross-section, defined at the respective part 323, 325, a respective convexly arcuate part 348b, 350b defined at the parts of 327, 329 of flange portions 318, 320, and a respective convex part 348c, 350c, these being at corners formed at the junctions between respective parts 319, 323 and 321, 325.

The element 312 is formed of plastics material having some resilience, particularly permitting the free end parts 327, 329 to be resiliently deformed away from each other.

The element 314 is in the form of a holding device to be coupled to element 312 so as to extend therefrom to receive articles. Element 314 comprises a body portion 365 having a projection 336 at a rear end of the element 314.

The projection 336 has upper and lower surface formations 337, 339, generally complementary in shape to the parts 348a, 348c and 350a, 350c of formations 348, 350 on element 312. Thus, each has a concave part 337c, 339c and a generally linear part 337a, 339a. Parts 337a, 339a diverge somewhat, away from body 365. The part 339a also joins a part 339b of formation 339, this part converging somewhat towards formation 337 so that a comer 351 is formed at the junction of parts 339a, 339b. The dimensions of these and other parts of the projection 336 are arranged so that, in the assembled position of the elements 312, 314, the projection 336 is resiliently gripped by the flanges 315, 317 of element 312, the latter being slightly outwardly sprung.

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Assembly of the elements 312, 314 is effected by the action illustrated in Figures 16 and 17. First, the projection 336 of element 314 is advanced towards the gap between flanges 315, 317 and, with the element 314 angled upwardly, the part 337c of formation 337 of the element 314 is engaged with part 348c of formation 348 on element 312. At this point, corner 351 of projection 336 rests on flange 317, at the location of part 350c of surface formation 350. The element 314 is then swung downwardly to pivot around the corner formed by part 348c of surface formation 348, so that corner 351 moves along part 350a of surface formation 350 and, by camming action, forces the flanges 315, 317 apart to permit the projection 336 of element 312 to enter between the flanges and assume the final position shown in Figure 17. During the final part of this movement, the flanges may be permitted to close towards each other slightly, under natural resilience thereof, to produce a good snap action fitting. In the assembled condition, parts 348a and 348c of surface formation 348 on element 312 are in line contact with parts 337a, 337c of surface formation 337 on element 314, while parts 350a, 350c of surface formation 350 on element 312 are in line contact with parts 339a, 339c of surface formation 339 on element 314.

Because of the described divergent configuration of the parts 337a, 339a of surface formations 337, 339 on projection 336, and the complimentary configuration of the parts 348a, 350a of surface formations 348, 350, a kind of wedging action is provided which inhibits outward movement of the element 314 away from element 312. Inward movement of the element 314 relative to element 312 is limited by engagement of shoulders 365a, 365b on the element 314 with the parts 348c, 350c of the surface formations 348, 350 on element 312. Also, in the described arrangement, the free outer end of the projection 336, adjacent surface formation 337 is, in the assembled coupling, positioned immediately adjacent the part 327 of flange 315 to further limit inward movement.

As shown in Figures 18 and 19, body 365 is formed as a pair of outwardly extending arms 370, 372. Each arm has a part 370a, 372a which extends outwardly from an end wall 374 of the body 365, on which wall is formed projection 336. The arm parts 370a, 372a extend in parallel relationship outwardly to respective curved

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portions 370b, 372b and thence to respective portions 370c and 372c which extend back again towards wall 374. These are arranged to diverge slightly in the direction from the portions 370b, 372b, towards the wall 374, and to terminate somewhat short of wall 374.

A gap is formed between the portions 370c, 372c of the arms 370, 372 and articles, such as broom handles or the like may be inserted into this gap to be resiliently gripped by the portions 370c, 372c which are resiliently outwardly deformable relative to each other.

Figure 20 shows an element 414 with a projection 436 which is effective in use in a similar way to the projection 336 last described. In this case, the projection is, however, of bifurcated form having two outwardly extending ribs 436a, 436b, which diverge away from the body of the element 414, rib 436b being somewhat shorter in extent than rib 436a, to facilitate entry of the projection.

Figure 21 shows another adaptation of the element 314. Here the element 514 is in the form of an open topped container having a projection 536 similar to the projection 356 on element 312, but the projection 536 has an upper rib 536a, like rib 436a, and downwardly extending ribs 536b at spaced locations along the length of rib

536a.

Figure 22 shows an adaptation of the invention, being a shelf unit 612, where an element 612a similar to element 312 is incorporated with a shelf element 612b.

The described constructions have been advanced merely by way of explanation, and many modifications and variations may be made thereto without departing from the spirit and scope of the invention which includes every novel feature and combination of features herein disclosed.

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