GB2361741A

GB2361741A - A fastener for use with electrical equipment

Info

Publication number: GB2361741A
Application number: GB0010460A
Authority: GB
Inventors: Richard Weatherley
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-04-28
Filing date: 2000-04-28
Publication date: 2001-10-31
Anticipated expiration: 2020-04-28
Also published as: GB0010460D0; GB2361741B

Abstract

A fastener for securing two items together, such as electrical equipment to a housing structure, comprises a one piece plastic moulding defining a flange plate 4 and one or more insert members 12 for passing through aligned holes in the two items to be secured. The insert members 12 can be compressed towards the base plate 4 by screw threaded bolts passing through the inserts which engage screw threaded inserts 28 located in the insert members 12. Compression of the inserts 12 forces resilient legs 18 to splay out thereby securing the two items. The fastener is provided with clip members 20 to allow the fastener to be secured to one of the items to be fastened prior to fastening the other item. The insert members 12 are adapted to be pressed through the standard square aperture used for securing electrical equipment.

Description

2361741 FASTENER The present invention relates to fasteners and,

particularly, but not exclusively, to fasteners used to secure electrical equipment to a housing structure. The electrical equipment to be secured may, for example, be a computer network hub, a switch or a patch panel. This equipment may or may not be mounted on a rack.

Electrical equipment is typically secured to a housing structure by means of a nut and bolt arrangement. Each end of an electrical equipment rack is generally provided with a plurality of apertures which, when the rack is positioned as required for mounting, coaxially align with a corresponding plurality of apertures provided in the associated housing structure.

Conventionally, each aperture has a square shape with sides having a length of 9.5min. The apertures are generally arranged in a straight line and in groups of three. In each group of three, two apertures are spaced from one another by 31.7Omm with the third aperture spaced equi-distant therebetween. Adjacent apertures of consecutive groups are typically spaced from one another by 12.7Omm. Those persons skilled in the art will be familiar with the aforementioned standard arrangement for apertures associated with the mounting of electrical equipment racks.

The nut and bolt arrangement traditionally used to secure a rack of electrical equipment to a housing structure is time consuming, inconvenient and expensive to use. Prior to the positioning of the electrical equipment rack in the housing structure, the person performing the fitting operation must first attach a captive nut to each of the mounting apertures of the housing structure. Generally speaking, each nut is retained in a cage structure which itself incorporates sprung clips for engaging opposing sides of a given square mounting aperture. A captive nut may therefore be secured adjacent to a mounting aperture in a relatively rapid manner. However, in the circumstances where there is a large number of mounting 2 apertures to be used, the task of fitting the captive nuts is nevertheless undesirably labour intensive. Indeed, it is frequently the case that captive nuts are mistakenly fitted to mounting apertures of a housing which do not coaxially align with the apertures of the particular electrical equipment rack (or discrete item of electrical equipment) to be secured. The necessary corrective action is again labour intensive.

Once the captive nuts have been secured to the housing structure, the electrical equipment rack may be located in the required mounting position. Once in position, the rack may be secured to the housing structure by inserting a bolt through each coaxially aligned pair of apertures and into the associated captive nut. Conventionally, the bolts are M5 pan-head screws. This in itself may also be undesirably time consuming since the captive nuts will not always be precisely aligned for readily receiving their respective bolts. It is therefore quite possible for a nut and bolt pairing to be cross-threaded. This is particularly undesirable since it may not be possible to replace the damaged captive nut without first removing the rack being secured. Where the majority of nut and bolt pairings have been fully tightened, such a removal exercise can be inconvenient and expensive.

It is an object of the present invention to provide means for conveniently and inexpensively securing a rack of electrical equipment to a housing structure in a rapid and reliable manner.

A first aspect of the present invention provides a fastener for securing two or more items together, the fastener comprising a flange base for locating adjacent an item to be secured; an insert member for pressing through coaxially located apertures provided in items to be secured, the insert member being movable relative to the flange base; a securing member resiliently attached to at least one of the flange base and insert member so as to be forced laterally of the insert member when the insert member is moved, in use, to an item securing position; and means for moving the insert member to said securing position and for retaining the insert member in said securing position.

3 A fastener according to the present invention may be used to secure together two or more items such as a rack of electrical equipment and a housing structure. Said fastener is particularly suited to securing items having coaxially locating apertures. The insert member of the fastener may be located in a set of coaxially located apertures of items to be secured. The relative positioning of the fastener and said items is such that said items are positioned between the flange base and the securing member of the fastener. With the fastener and said items so located, the means for moving and retaining the insert member may be used to move the insert member relative to the flange base and thereby force the resilient securing member to be moved laterally. The lateral movement of the securing member prevents the insert member from being withdrawn through the coaxially located apertures. Accordingly, said items are thus trapped between the flange base and securing member of the fastener and are thereby secured together.

It is preferable for the fastener to comprise means for allowing the fastener to be attached to one of said items to be secured prior to said items being secured with the fastener. 71his attachment means preferably comprises a resilient clip. The attachment means may be adapted so as to trap said one of said items between said clip and the flange base of the fastener. The attachment means may be mounted to the flange base or the insert member.

The flange base, insert member and securing member may be formed as a unitary component. Where the fastener is provided with said attachment means for allowing fastener attachment said attachment means may be comprised in said unitary component. Said unitary component may be a one piece moulding of nylon or acetal.

Said means for moving and retaining the insert member comprises a screw thread associated with said insert member. Said moving and retaining means preferably comprises a nut or bolt for threadedly engaging the screw threads associated with the insert member and reacting a force for moving and retaining the insert member against the flange base. It is preferable for the screw thread 4 associated with the insert member to be provided by means of a threaded insert pressed into the insert member. The threaded insert is preferably of brass. The threaded insert may threadedly engage with a bolt or screw, the head of which bolt or screw transmits to the flange base a force generated in moving and retaining the insert member.

The fastener may be sized so that the insert member can be pressed through an aperture having a 9.5mm by 9.5mm square shape. The means for moving and retaining the insert member may comprise a M5 bolt or screw.

A second aspect of the present invention provides a fastener assembly comprising two or more of the aforementioned fasteners attached to one another. Said fasteners are preferably attached to one another in a straight line. Furthermore, the fastener assembly is ideally provided as a unitary component. It is also preferable for the fastener assembly to comprise three of the aforementioned fasteners, wherein two of said fasteners are spaced from one another by 3 1.70mm with the third fastener spaced equi-distant therebetween. A fastener of the fastener assembly is preferably attached to its adjacent fastener at its base flange. Fasteners of the fastener assembly may be detachable from one another by means of a tear feature provided between adjacent fasteners.

A third aspect of the present invention provides electrical equipment or a housing structure for receiving electrical equipment, wherein said electrical equipment or housing structure is provided with one or more of the aforementioned fasteners or fastener assemblies.

Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

Figures 1 and 2 are perspective views of a first embodiment of the present invention; Figure 3 is a top plan view of the first embodiment; Figure 4 is a side view of the first embodiment; Figure 5 is a bottom plan view of the first embodiment; Figure 6 is a cross-sectional view taken along the line A-A as shown in Figure 3; Figure 7 is a cross-sectional end view of the first embodiment; and Figure 8 is a bottom plan view of an alternative embodiment of the present invention.

Two perspective views of a fastener assembly 2 according to the present invention are shown in Figures 1 and 2 of the accompanying drawings. Further views of the fastener assembly 2 are shown in Figures 3 to 7. The fastener assembly 2 is provided with a planar flange base 4 having three equally spaced apertures 6,8, 10. The three apertures 6,8, 10 are arranged in a straight line. Two of the apertures 6, 10 are spaced from one another by 3 1.70mm with the third aperture 8 spaced equi-distant therebetween. Each aperture 6,8, 10 is sufficiently large to allow the passage therethrough of an M5 bolt or screw shaft. However, each of the apertures 6,8, 10 is sufficiently small to prevent the passage therethrough of an M5 bolt head or screw head.

An insert member 12 is associated with each of the apertures 6,8, 10. Each insert member 12 is cylindrical in shape and sized so as to be insertable in a square aperture with sides having a length of 9.5min. Each insert member 12 is spaced from the flange base 4 and orientated so that a bore 14 extending through each insert member 12 is located coaxially with the associated aperture 6,8, 10. The arrangement is such that a threaded bolt or screw can be inserted through one of the apertures 6,8, 10 and into the bore 14 of an associated insert member 12. Each insert member 12 is attached to the flange base 4 by two curved plates 16,18. The plates 16,18 are curved outwardly so as to bend and displace laterally away from the axis of the associated aperture 6,8,10 and bore 14 when the associated insert member 12 is moved towards the flange base 4. The curved plates 16,18 are located on opposite sides of an associated aperture 6,8,10. In use, the curved plates 16,18 resiliently deforin so as to press two or more items against the flange base 4.

In addition to the curved plates, each insert member 12 is provided with two 6 sprung clip members 20,22. The sprung clip members 20,22 are located on opposite sides of the associated insert member 12 and extend toward the flange base 4. Each of the sprung clip members 20,22 has a cam surface 24 for engaging an aperture wall of an item to be secured. The cam surface 24 is such that the associated clip member is forced laterally towards the axis common to the bore 14 and associated aperture 6,8, 10 when the associated insert member 12 is pressed through an item aperture of the aforementioned dimensions. The clip members 20,22 are spaced from the flange base 4 and have a shoulder 26 for snap fitting over an item to be secured. Accordingly, the sprung clip members 20,22 allow the fastener assembly 2 to be pressed through the aforementioned item apertures of a first item and to be thereby snap fitted to said first item prior to the securing of said first item to one or more other items. The arrangement of the sprung clip members 20,22 is most clearly shown in Figure 6 of the accompanying drawings. The flange base 4, the insert member 12, the curve plates 16,18 and the sprung clip members 20,22 are manufactured as a unitary moulding of acetal. Any other resilient material may be used as an alternative, for example, nylon.

A cylindrical brass insert 28 is located in each insert member 12 of the fastener assembly 2 (although only one insert 28 is illustrated in the accompanying drawings - see Figure 1). Each insert 28 is provided with an internal thread for engaging with a bolt or screw which is inserted into the bore 14 via the associated aperture 6,8, 10. An insert 28 is positioned within its associated insert member 12 by pressing said insert 28 into the bore 14 of the insert member 12 from the end of the insert member 12 distal to the flange base 4. The outer surface of each insert 28 is provided with serrations (not shown in the drawings). These serrations engage the associated insert member 12 and tend to prevent the insert 28 from undesirably falling from the associated bore 14. The bore 14 of each insert member 12 is provided with a shoulder 30 against which an insert 28 locates. The shoulder 30 ensures the correct positioning of an insert 28 within the bore 14 of an insert member 12.

7 In use, the fastener assembly 2 may be used to secure together tVVo or more items. Typically, these items will be mating sheets of metal which may, for example, be associated with a rack of electrical equipment and a housing structure. Each insert member 12 is pressed through coaxially located apertures in the items to be secured. The fastener assembly 2 will be pressed into said apertures sufficiently far for the planar flange base 4 to abut one of said items. The dimensions of the fastener assembly 2 relative to the combined thickness of said items is such that at least half of the length of the curved plates 16,18 extends from the item apertures. The dimensioning of the fastener assembly 2 is such that sufficient lengths of the curved plates 16,18 are free from said items so as to allow a lateral displacement of the curved plates 16,18. When the fastener assembly 2 is located in the item apertures, each bolt or screw extending through the fastener apertures 6,8, 10 and engaging associated inserts 2 8 is rotated so as to draw the insert and associated insert member 12 towards the flange base 4. As the insert member 12 moves towards the flange base 4, a compressive force is applied to the curved plates 16,18. This compressive force causes the curved plates 16,18 to buckle and displace laterally. This in turn presses said items to be secured against the flange base 4 and prevents the insert members 12 from being withdrawn through the item apertures. Said items are thus secured together. Since the curved plates 16,18 are of a resilient material, the bolts or screws may be rotated so as to relieve said compressive force and allow withdrawal of the insert members 12. The fastener assembly 2 may then be reused as necessary.

Items to be secured to other items may be provided with one or more fastener assemblies snap fitted thereto. This is achieved through use of the spring clip members 20,22 of the fastener assembly. With the fastener assembly snap fitted in position, the item in question is located between the clip shoulder 26 and the flange base 4. Said item may then be conveniently secured to a further item without the possibility of the fastener assembly 2 being misplaced.

The present invention is not limited to the specific embodiments described above. Alternative arrangements will be apparent to a reader skilled in the art. For example, the fastener assembly 2 is adapted for engagement with three sets of coaxially located item apertures. However, a fastener assembly may be provided which is adapted to engage more or less than three such sets of apertures. Furthermore, the fastener assembly may be adapted to engage sets of apertures having different sizes with differing spacings therebetween.

An alternative fastener assembly 102 is shown in Figure 8 of the accompanying drawings. This assembly 102 is identical to the previously described fastener assembly 2 except in that the assembly 102 is adapted for engagement with only two sets of coaxially located item apertures and in that the flange base 4 is provided with tear features 104 which allow a group of fastening components (i.e. a flange base 4, an insert member 12, curved plates 16,18 and spring clip members 20,22) to be conveniently separated from neighbouring fastener components. In the assembly 102 of Figure 8, neighbouring fastener components are connected merely by narrow elongate lengths 106 of material. This construction not only assists in the convenient separation of neighbouring fastener components, but also reduces manufacturing costs.

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Claims

CLAIMS:

1. A fastener for securing two or more items together, the fastener comprising a flange base for locating adjacent an item to be secured; an insert member for pressing through coaxially located apertures provided in items to be secured, the insert member being movable relative to the flange base; a securing member resiliently attached to at least one of the flange base and insert member so as to be forced laterally of the insert member when the insert member is moved, in use, to an item securing position; and means for moving the insert member to said securing position and for retaining the insert member in said securing position.

2. A fastener as claimed in claim 1 further comprising means for allowing the fastener to be attached to one of said items to be secured prior to said items being secured with the fastener.

3. A fastener as claimed in claim 2, wherein the attachment means comprises a resilient clip.

4. A fastener as claimed in claim 2 or 3. wherein the attachment rneans is adapted so as to trap said one of said iterns between said clip and the flange base of the fastener.

5. A fastener as claimed in any of claims 2 to 4, wherein the attachment means is mounted to the flange base or the insert men-iber.

6. A fastener as claimed in any ofthe preceding claims, wherein the flange base, insert member and securing nieniber are 1'ormed as a unitary coinponent.

A fastener as claimed in claim 6 and any of clairns 2 to 5, wherein the attacl-u-nent means is comprised in said unitary component.

8. A fastener as claimed in claim 6 or 7, wherein said unitary component is a one piece moulding of nylon or acetal.

9. A fastener as claimed in any of the preceding claims, wherein said rneans for moving and retaining the insert member comprises a screw thread associated with said insert member.

10. A fastener as claimed in clairn 9, wherein said moving and retaining means comprises a nut or bolt for threadedly engaging the screw threads associated with the insert member and reacting a force for moving and retaining the insert member against the flange base.

11, A fastener as claimed in clairn 9 or 10, wherein the screw thread associated with the insert member is provided by ineans of a threaded insert pressed into the insert member.

12. A fastener as claimed in claim 11, wherein the threaded insert is of brass.

13. A fastener as claimed in claim 11 or 12, wherein the threaded insert is threadedly engaged with a bolt or screvv, the head of which bolt or screw transmits to the flange base a force generated in moving and retaining the insert member.

14. A fastener as claimed in any preceding claim, wherein the insert member can be pressed through an aperture ha-vin- a 9.5min by 9.5i-ni-ii square shape.

15. A fastener as claimed in an)! preceding claim, wherein tile illeans for moving and retaining the insert member may comprise a M5 bolt or screw.

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16. A fastener assembly comprising two or i-nore fasteners attached to one another, wherein at least two of said fasteners are each a fastener according to any preceding claim.

17. A fastener assembly as claimed in claim 16, wherein said fasteners are attached to one another in a straight line.

18. A fastener assembly as claimed in claini 16 or 17, wherein the assembly is a unitary component.

19. A fastener assembly as claimed in any of claims 16 to 18, the assembly comprising first and second fasteners spaced from one another by 31.7Omm with a third fastener spaced equi-distant therebetween wherein the first, second and third fasteners are each a fastener according to any of claims 1 to 15.

clairns 16 to 19, wherein each

20. A fastener assembly as claimed in any o.

fastener of the fastener assembly is attacheid to an ajacent fastener at its base 1, flange.

21. A fastener assembly as claimed in any of claims 16 to 20, wherein at least one fastener of the fastener assembly is delachable from the remainder of the fastener assembly by means of a tear ficature provided between ajacent fasteners.

22. Electrical equipment or a housing sti-uctire for receiving electrical equipment, wherein said electrical eqtili)iiieiit or housing structure is provided with at least one fastener as claimed in any ofelainis 1 to 15 or fastener assembly as claimed in any of claims 16 to 2 1.