GB2147289A

GB2147289A - A method of bonding parts together

Info

Publication number: GB2147289A
Application number: GB08424462A
Authority: GB
Inventors: Herwig Scheidler
Original assignee: Carl Zeiss AG; Schott Glaswerke AG
Current assignee: Schott AG; Carl Zeiss AG
Priority date: 1983-10-01
Filing date: 1984-09-27
Publication date: 1985-05-09
Also published as: FR2552684A1; DE3335784A1; GB2147289B; FR2552684B3; GB8424462D0

Abstract

Parts (1 and 2) which can be made of various materials are bonded together by applying sufficient adhesive to one of the parts (2) to enable the adhesive, when the parts (1 and 2) are offered to each other to pass around an edge of the other part (1) or through at least one opening provided in the other part to form a mass of the adhesive (3) which is deformed into a catch region (5) which provides after the adhesive has set, a mechanical portion to the joint. The adhesive is deformed into the catch region either by a fixed abutment on the other part or by a removable tool or gauge. <IMAGE>

Description

SPECIFICATION A method of bonding parts together The present invention relates to a method of bonding parts together, and more particularly by means of an adhesive.

It is known to use permanently elastic adhesives to bond parts, more particularly parts having different thermal expansions. From the prior art, it is known, when using adhesives which need to react with air (moisture) to form openings in one or both of the parts to be bonded, so that the adhesive can react with air through the holes.

When parts are stuck together, more particularly when made of different materials, bonding is often difficult because if the surfaces are unsuitable for bonding, badly cleaned or otherwise defective, the bonds between the stuck parts will not be durable, since even a small mechanical load will loosen or break the adhesive from the stuck parts. These situations can be termed adhesion cracks.

It is an object of the present invention to provide a method of bonding or joining parts, more particularly parts made of different materials which reduces the risk of bonded parts from separating in the event of adhesion cracks.

According to an aspect of the present invention there is provided a method of bonding together parts by means of adhesive material, characterised in that sufficient adhesive is used to enable the adhesive when applied to one of the parts whilst in a viscous state to pass, on being offered to a further part to be bonded thereto, around a edge provided on the further part or through at least one opening provided in the further part to an extent sufficient to enable the adhesive to be shaped to provide a catch region which after the adhesive has set or reacted augments the joint between the parts.

Preferably an abutment or abutments is or are disposed at a suitable distance above or behind the edge or opening(s) so as to deform the adhesive passing through the opening(s) or past the edge to produce the associated catch region.

With this method of the invention it has been found that during or immediately after the bonding the abutment or abutments deform(s) the adhesive, i.e., laterally relative to the edge or free crosssection of the opening(s) whereby the thus deformed adhesive forms the catch region. After the adhesive has completely set,cured or reacted, the joint between the parts is augmented by the catch region which defines a mechanical form of joint region. It has been found possible to shape the catch regions in such manner that the bond to one of the parts can be produced by the catch region, without the need for adhesion between adhesive and said one of the parts.

The method of the invention has been found to be particularly suitable for joining parts of vitreous materials to plastics or metal parts having surface coatings. As is known surface coating provide surfaces which differ greatly in adhesiveness, depending upon the method of manufacture and surface treatment. With surface coated parts it has been found that during bonding adhesion cracks frequently occur, resulting in manufacturing defects owing to inadequate bonding of the adhesives to these materials. On the other hand it has been found that adhesives such as silicone adhesives, adhere very firmly to glass, so that abutments are rarely needed in such cases.

Conveniently, the perforated part is formed directly, by suitable shaping, with abutments, which automatically shape the adhesive into a rear catch after it has passed through.

If the holes and abutment are suitably shaped, the parts for sticking can be bonded even without the perforated part forming a permanent adhesive bond, since the bond is produced entirely by the rear mechanical catch. A mechanical bond of this kind can be as strong as the tearing strength as the adhesive. If the mechanical bonding strength is appreciably below the tearing strength of the adhesive, the bond can be broken by suitable force which may be useful for service purposes or in the case of manufacturing errors.

In large scale production of articles having bonded parts or if the bonded parts have a simple shape, the abutment can temporarily be formed by an adhesive gauge which forms the catch region and which is removed after the adhesive has set or set sufficiently to retain the desired catch region. It will be understood that the gauge must not be adherable to the adhesive. In the case of some simple-shaped bonds, the adhesive can be formed into a rear catch region by shaping the adhesive with an auxiliary tool after the adhesive has travelled through the holes or around the edge of the part being bonded. Once again, the tool must not be adherable to the adhesive.

The method according to the invention has been found suitable for bonding glass parts to metal and/or plastics frames or corners of for bonding handles or the like to hollow glass vessels, e.g., containers for coffee-machines. The method can be used for bonding other materials.

For a better understanding of the invention refer- ence will now be made to the accompanying drawings in which: Figure la is a section on the line Ia-Ia of Figure 1b Figure lb is an elevation of a first embodiment of the method of the invention; Figure 2a is a section on the line Ila-Ila of Figure 2b; Figure 2b is an elevation of a second embodiment of the method of the invention; Figure 3a is a section on the line lIla-Ill of Figure 3b; Figure 3b is an elevation of a third embodiment of the method of the invention; Figure 4 is a section of a fourth embodiment of the method of the invention; Figure 5 is a section of a fifth embodiment of the method of the invention; and Figure 6 is a section of a sixth embodiment of the method of the invention which utilises an adhesion gauge.

In Figures 1a and 1b the references 1 and 2 rep resent the parts to be bonded or joined together.

As shown holes or apertures are formed in the part 1 in such manner as to provide a portion 4 that overhangs each hole or aperture to provide an abutment effectively spaced from the plane of the portion of the part 1 having the hole or aperture.

The parts 1 and 2 are bonded by adhesive 3. The quantity of adhesive used is sufficient to provide adequate spread on the part 2, pass through the hole or aperture to cooperate with the abutment 4 of the part 1 to provide a layer of adhesive which overhangs the periphery of the hole or aperture as at 5 to provide the so-called catch region. With this arrangement of the adhesive when the latter has set, cured, reacted or otherwise solidified to form the requisite bond to the parts 1 and 2, the catch forming part 5 defines a mechanical lock or joint with the part 1 which is such that even though the adhesive bond with the part 1 may be inadequate in that the adhesion bond includes adhesion cracks the mechanical connection of the catch 5 defines an adequate joint between the parts.

In the embodiment of Figures 2a and 2b the individual abutments of the holes or apertures of Figures 1a and 1b are replaced by a common channel shaped member 4 which is secured to the part 1 to provide the catch forming abutment.

In the embodiment of Figures 3a and 3b an elongate portion of the part 1 is deformed so as to overly a further portion of the part 1 to produce a Vee shaped channel into which adhesive is directed to provide the catch 5.

Figure 4 schematically illustrates an means of bonding a channel shaped part 1 to the part 2 by providing an internal abutment 4 similar to that of Figure 1a, against which adhesive 3 cooperates to provide the catch 5.

Figure 5 schematically shows in cross-section the connection of a part 1 with a flange or rim provided with holes or apertures and the abutments 4 which is intended to connect with a flat surface of the part 2.

Figure 6 illustrates in section a means of producting a catch 5 by using a so called adhesive gauge 6, which latter defines the abutment surface for deforming the adhesive 3 into the catch 5. As will be noted in the arrangement shown the gauge 6 serves as a tamping tool for flattening the adhesive 3 passing through the hole or aperture into the catch. Once the catch has been formed the gauge is removed.

In the embodiments in which a common abutment is provided the common abutment can be secured in place by welding, riveting, soldering, screwing or the like

Claims

1. A method of bonding together parts by means of an adhesive material, characterised in that sufficient adhesive is used to enable the adhesive when applied to one of the parts whilst in a viscous state to pass, on being offered to a further part to be bonded thereto, around an edge provided in the further part of through at least one opening provided in the further part to an extent sufficient to enable the adhesive to be shaped to provide a catch region which after the adhesive has set or reacted augments the joint between the parts.

2. A method as claimed in claim 1, and in which one or more abutments are disposed at a suitable distance relative to the edge or opening(s) to produce said catch region.

3. A method as claimed in claim 2, and in which the abutments are formed directly during the process of producing the openings.

4. A method as claimed in claim 3, and in which when the openings are formed by a punching operation the abutments are produced by the same operation.

5. A method as claimed in claim 2, and in which the abutment(s) are each formed by surfaces separately located behind each opening and are directly produced during the shaping of the part having the openings.

6. A method as claimed in claim 2, and in which an abutment common to all of the openings provided in a part is associated with said part.

7. A method as claimed in claim 6, and in which the common abutment is formed by a bent sheet-metal flap or suitably formed abutment surface.

8. A method as claimed in claim 6, and in which the common abutment is formed by a separate surface secured behind, with respect to the direction of adhesive flow, the openings by welding, riveting, soldering, screwing or the like.

9. A method as c'aimed in claim 1, and in which the catch region is formed by applying an adhesive gauga or other tool to the adhesive so as to shape the latter after it has passed around said edge or through said opening(s), the gauge or tool being removed after the formation of the catch region.

10. A method of bonding together parts by means of an adhesive substantially as hereinbefore described with reference to Figures la, Ib; 2a, 2b; 3a, 3b, Figure 4 or 5; or Figure 6.

11. Parts when bonded together by the method as claimed in any one of the preceding claims 1 to 10.