GB2389883A

GB2389883A - Adhesive attachment boss

Info

Publication number: GB2389883A
Application number: GB0214453A
Authority: GB
Inventors: Gareth Phillips
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-06-22
Filing date: 2002-06-22
Publication date: 2003-12-24
Anticipated expiration: 2022-06-22
Also published as: GB2389883B; GB0214453D0

Abstract

A boss (10) for attachment to a base (18) by an adhesive joint has an adhesion surface (11) with a channel (14) formed in it. When adhesive (20) is applied to the adhesion surface (11), and pressure applied, the adhesive (20) is squeezed such that any excess is collected in the channel (14).

Description

Adhesive Attachment Boss The present invention relates to a boss for

attachment to a base by means of an adhesive joint, and to a method of forming an adhesive joint 5 between a first member such as a boss and a base.

The use of high strength adhesive joints in the construction of various high quality and precision items is growing more desirable due to the decreasing cost of the adhesive, its increasing ease of use and the improved visual appearance that can be achieved. This has been made possible by 10 improvements in the curing properties and adhesive strength of the bonds that may be formed.

For example, the desire to make furniture and other structures containing clear/translucent plastics and glass, as aesthetic and as structural elements, has increased. This and other factors has led to a need for better 1s adhesive bonds and joints by which the attachment of various other components to the glass or plastics can be achieved.

The attachment of one surface to another matching or compatible surface can be achieved by provision of suitable adhesive between those surfaces and the subsequent curing of the adhesive. However, when using 20 an adhesive that is liquid or flowable before curing, the squeezing action caused by the bringing together of the surfaces tends to force the adhesive outwardly (along the path of least resistance) such that it escapes around the edges. This creates an unsightly and/or hazardous mess that must either be cleaned before or after curing. This cleaning dramatically increases the work 2s involved in the creation of such an adhesive join. The problem has previously P1 2699-SP-0 1 doc

only been mitigated by the very careful application of the adhesive to ensure only the minimum is used, which in turn reduces the amount that can escape.

However, this does not reduce the amount of time or skill required to undertake the task, and in fact can reduce the strength of the bond. Therefore! 5 no practical advantage in construction is achieved.

As mentioned above the problems are particularly acute when: constructing furniture and structures which are to be on show or readily visible during use, because poor quality workmanship will detract from the value of the product. In constructions wherein a bond is formed to glass, the visibility 10 of the joint is greater - indeed the surfaces adhered together may remain visible after adhesion. Therefore the need for neat formation of the join is further increased. Glass or clear plastics can be used as sheet material to form shelves and tabletops and often must be attached to other structural elements such as legs or supports. This attachment can be achieved using t5 adhesive, but the translucent property of the glass or plastics means that the adhesive bond may be visible therethrough.

A further problem of adhesive bonds is than many adhesives are prone: to degradation over time, especially if exposed to damaging environmental conditions. This means that if adhesive joins were to be used in challenging 1 20 environments, only highly specialized adhesives will work. Unfortunately, i such specialised adhesives are highly expensive and often have undesirable characteristics. It is an aim of the present invention to provide a mechanism by which an adhesive joint may be formed simply and effectively between two matching 25 surfaces. It is a further aim to provide such a joint that prevents or controls P 12699-SP-Ot.tt"

- 3 the egress of adhesive from between the surfaces, without the need for precise adhesive application. It is a yet further preferred aim to reduce the chance of subsequent contact between users and the adhesive. A still further aim of a preferred embodiment of the present invention is to provide an 5 adhesive join in which the adhesive is isolated from external environment so that amongst other benefits the degradation of the adhesive is prevented.

Therefore according to the present invention there is provided a boss for attachment to a base by means of an adhesive joint, which boss has an adhesion surface with a profile that is compatible with the region of base to to which the boss is to be adhered, and a channel formed in said surface of the boss adjacent but inward of the periphery of the adhesion surface, whereby suitable placement of adhesive to attach the boss to the base and application of pressure to the joint, the adhesive will be squeezed outwardly and any excess adhesive will collect in the channel.

15 As used herein the term "boss" is intended to encompass any item adapted for attachment to a surface by adhesive. Such an item may be intended to facilitate the attachment of a further piece or pieces to the base, or it may comprise the complete attachment.

The channel may be a continuous (endless) loop extending around the 20 adhesion surface, or it may be discontinuous. The channel may have an end or ends that extend to the edge of the adhesion surface such that adhesive collected in the channel may escape from between the surfaces out the end of the channel. The escape of adhesive would indicate that the channel was full and that sufficient adhesive has been applied. To clean this small amount of 25 escaped adhesive is simple in comparison to cleaning all round the periphery P1 2G9'J-SP 01.doc

of the adhesion surface. The exposed end of the channel could also be used as an injection point should it be necessary to apply glue extemally.

To permit cohesion between the adhesion surface and the region of the base, the respective surfaces must be compatible over at least a significant 5 portion of their area. As long as the surfaces are similar, the present invention will find utility, because the adhesive will tend to be forced outwardly and so need collection in a channel. It is therefore possible that the adhesion surface and corresponding region of the base might have relatively complex shapes such as curves and undulations. However, in the majority of situations the 10 boss will be intended for attachment to a generally flat region of the base, and therefore it is preferred that the adhesion surface of the boss and the region of the base to which it is adhered are generally co-planar.

The channel needs to be large enough to accommodate the adhesive that is received therein, but may adopt any shape. Nevertheless, for ease of 15 manufacture and aesthetic appeal the channel may be generally v-shaped with an angle of approximately 90 between the sloping sides thereof. It may also be u-shaped or square in cross section, or it may be under cut such that its neck is narrower that other parts of the channel.

The boss may be formed in a number of shapes, however it is 20 preferred that the adhesion surface is generally circular, and that the channel (continuous or discontinuous) is formed circumferentially therein slightly in from the edge of the adhesion surface.

The boss may serve a variety of functions, and its outwardly facing parts may be adapted to permit those functions. For example the boss itself 25 may have a decorative function in which case the outwardly facing parts may P1 2699-SP01.doc

( be suitably configured. However, the boss may in many situations be used as a means of attaching other parts to the base. It is, therefore, preferred that the boss is provided with connection means to attach a further member thereto. The connection means may comprise a spigot extending from the 5 boss, which spigot may be received in a suitable recess in a further member that is to be attached. The spigot may be provided with a resilient member that is located therearound, and which forms a resilience fit between the spigot and the recess in the further member. More than one of these resilient members may be used and they may be located in grooves formed around 10 the shaft of the spigot. The resilient members may be rubber or plastics material o-rings. The spigot may alternatively be provided with threaded connection means, or other suitable mechanisms.

Such a boss may for example be used in the construction of stands for audio or video equipment. A boss may be used at both ends of a number of 5 tubular legs to connect together two or more shelves formed from sheets of plate glass. The resilient members dampen any vibrations carried in the stand and prevent the transmission and propagation of these vibrations between the shelves and legs, as this propagation can have a detrimental effect on sound quality. 20 The boss according to the present invention will find many applications, but one clear use will be in the construction of furniture and structures containing glass and plastics, and for such applications it is preferred that the boss be specifically adapted for use in the construction of such items.

The boss may have more than one channel formed therein, and these 25 channels may be concentric. These multiple rings can be used to provide a P1 2699 -SP1.doc

- 6 safety feature, in that should adhesive pass one channel the next will collect it.

They can also be used to protect the adhesive from external environmental degradation. In such an alternative, a sealing material or sealing ring may be located in a channel (usually the outermost) out side the channel in which the 5 adhesive is to collect. When the boss is adhered to the base the sealing material forms a barrier between the adhesive and the ambient environment such that the adhesive is protected from exposure thereto. For example a bead of silicone sealant could be used to protect a water-based adhesive from degradation by external moisture. The sealing material could also prevent 10 components in the adhesive from escaping, which could either result in degradation of the adhesive or, if the components are undesirable, their having a detrimental effect.

The sealing material may also be flowable, and may be placed on the adhesion surface inwardly of the outermost channel, such that when the boss is adhered to the base the sealing material isolates the adhesive. The compression of the base and boss will force any excess sealing material to collect in a channel outward of the channel in which the adhesive collects.

According to the present invention there is also provided a method for attaching a first member to a base by means of an adhesive joint, which 20 method comprise the steps of providing a first member with an adhesion surface of the same profile as the region of base to which the first member is to be adhered; forming a channel in said surface of the first member adjacent but inward of the periphery of the adhesion surface; placing uncured flowable adhesive on the adhesion surface within an area defined by the channel or 25 placing adhesive on the corresponding area of the base; bringing the first P12699-SP-O1 doc

I ( member and the base together such that the adhesive will be squeezed outwardly and any excess adhesive will collect in the channel; and curing or allowing to cure the adhesive.

When the first member and the base are brought together pressure or 5 force may be directly applied to the join to squeeze the adhesive, or the force of gravity may be used.

The placing of the flowable adhesive does not need to be that accurate.

Whilst it may be generally in the centre of the adhesion surface, the channel provided by the present invention will prevent the adhesive from exiting from 10 between the surfaces even if the adhesive is not centrally applied. If adhesive is placed off centre, when squeezed it will flow outwardly and reach one part of the channel first. However, the adhesive will tend to follow along the channel and fill it before it flows out the other side and risks egress.

In order that it may be better understood, but by way of example only s the present invention will now be described with reference to two particular embodiments shown in the accompanying drawings in which: Figure 1 is a cross-section through a first embodiment of boss when 3 attached to a base and a further member in the form of a leg; Figure 2 is a perspective view of the same embodiment of boss but 20 with no other parts showing; Figure 3 is a plan view of the same embodiment of Figure 2; and Figure 4 is a cross-section through a second embodiment of boss -I when attached to a base and a further member in the form of a leg.

Referring to Figures 1, 2 and 3 there is shown a boss generally 25 indicated 10, which has a generally circular adhesion surface 11 on one side Pl 2699-SP1 bloc

-8 (and a cylindrical spigot 12 extending away therefrom on the other side. A v- i shaped channel 14 is formed in the adhesion surface 11 and extends circumferentially (although not necessarily regularly) therearound. Annular grooves 15, 16 are formed in the sides of the spigot 12. The boss may be 5 formed from any suitable material, but metal or plastics that have been machined, cast or injection moulded are particularly useful.

This embodiment of boss 10 is adapted to releasably connect a base,; in the form of a glass panel 18, to a generally cylindrical leg 19 - the glass panel and leg being shown only in Figure 1. The adhesion surface 11 is i to connected to the underside of the glass panel 18 by adhesive 20, which is cured by UV light in an anaerobic atmosphere. The uncured adhesive is flowable and is applied to approximately the centre of the adhesion surface 11 within the area defined by the channel 14. (It could also be applied to the corresponding part of the glass panel 18.) The boss 10 is then brought into 15 contact with the area of the glass panel 18 to which it is to be attached. When the boss is pressed up against the glass panel 18, the compression therebetween forces the adhesive outwardly toward the channel. As the adhesive 20 moves outwardly it ensures good adhesive contact between the adhesion surface 11 and the glass panel 18. When it reaches the channel 14 20 any excess adhesive 20 collects therein and is prevented from further outward movement, thereby stopping it emerging from between the boss 10 and panel 18 around the edge of the boss 10.

Rubber o-rings 21 are located in the grooves 15 and 16. The generally cylindrical leg 19 is connected to the boss 10 by locating the spigot 12 in a 25 corresponding shaped recess 22, and is a resistance fit therein. When the P12699-SP O1 doe

- 9 - spigot 12 is inserted into the recess 22, the o-rings 21 are squeezed i therebetveen and this holds the two parts together. The leg 19 is shown as solid, with a recess at the end thereof, but could instead be tubular along its length, with the spigot matching the size of the tube.

5 The joint between the boss and the leg is predominantly through rubber, so generally no rigid materials come into contact, and this therefore acts as a damper. When the boss is used in the construction of a hi-fi or; audio stand this can dramatically improve the quality because it prevents the transmission of vibrations through the stand from one piece of equipment to i 10 another. Figure 4 shows a second embodiment that is very similar to that shown in Figures 1 to 3, and like parts will be given like reference numerals. This second embodiment of boss, generally indicated 24, differs in that a second channel 25 is formed in the adhesion surface 11 outside the v-shaped channel 15 14. A bead of sealant 26 is located in this second channel 25, such that when the adhesion surface 14 and the glass panel 18 are brought into contact the sealant 26 isolates the adhesive from the external environment.

P1 2699-SP-O1.d3c

Claims

- 10 Claims

1. A boss for attachment to a base by means of an adhesive joint, which boss has an adhesion surface of the same profile as the region of base to 5 which the boss is to be adhered, and a channel formed in said surface of the boss adjacent but inward of the periphery of the adhesion surface, whereby suitable placement of adhesive to attach the boss to the base and applying of; pressure to the joint, the adhesive will be squeezed outwardly and any excess adhesive will collect in the channel. i to

2. A boss as claimed in claim 1, wherein the adhesion surface of the boss and the region of the base to which it is adhered are generally co-planar.

3. A boss as claimed in claim 1 or claim 2, wherein the channel is generally v-shaped, u-shaped or square in cross-section.

4. A boss as claimed in any of the preceding claims, wherein the 5 adhesion surface is generally circular, and the channel is formed circumferentially therein.

5. A boss as claimed in any of the preceding claims in which the boss is provided with connection means to attach a further member thereto.

6. A boss as claimed in claim 5, wherein the connection means comprise 20 a spigot which extends from the boss and at least one resilient member which extends around the spigot such that the spigot may be received in a suitable recess provided in the further member to which the boss is to be attached.

7. A boss as claimed in any of the preceding claims, wherein the base is a glass or plastics material panel.

Pt2699-SPO1 doe

- 11 (

8. A boss as claimed in any of the preceding claims, which is specifically adapted for use in the construction of furniture or in the construction of stands for audio or video equipment.

9. A boss as claimed in any of the preceding claims, wherein a part of the channel extends to the edge of the adhesion surface and adhesive can emerge therefrom.

10. A boss as claimed in any of the preceding claims, wherein more than one channel is formed in the adhesion surface.

11. A boss as claimed in claim 10, wherein the channels are concentrically f o formed.

12. A boss as claimed in claim 10 or claim 11, wherein one or more of the channel is filled with a sealing material that isolates the adhesive from the ambient environment when the boss is adhered to the base.

13. A boss as claimed in claim 10 or claim 11, wherein a plowable sealing material is placed on the adhesion surface inwardly of the outermost channel, such that when the boss is adhered to the base the sealing material isolates the adhesive, and any excess sealing material collects in a channel outward of the channel in which the adhesive collects.

14. A boss as claimed in any of the preceding claims, wherein the or each 20 channel which is adapted to receive adhesive contains an adhesive absorbing material.

15. A boss as claimed in claim 1 and substantially as herein described with reference to and as illustrated in the accompanying drawings.

16. A method for attaching a first member to a base by means of an 25 adhesive joint, which method comprise the steps of providing a first member P1 2699-SP1.doc

- 12 with an adhesion surface of the same profile as the region of base to which the first member is to be adhered; forming a channel in said surface of the first member adjacent but inward of the periphery of the adhesion surface; placing uncured plowable adhesive on the adhesion surface within an area defined by 5 the channel or placing adhesive on the corresponding area of the base; bringing the first member and the base together such that the adhesive will be squeezed outwardly and any excess adhesive will collect in the channel; and curing or allowing to cure the adhesive.

17. A method as claimed in claim 16, wherein the adhesive is cured by to electromagnetic radiation in the ultra-violet spectrum.

18. A method as claimed in claim 16 or claim 17, wherein a second channel is formed outside the said channel into which the adhesive is received, and this second channel is adapted to receive a sealing material such that when the base and the first member are brought together, the 15 adhesive is isolated from the ambient environment.

P1 26995P4)t.doc