GB2063975A

GB2063975A - Strip Structures for Trimming and Sealing

Info

Publication number: GB2063975A
Application number: GB7941842A
Authority: GB
Original assignee: Silent Channel Products Ltd
Current assignee: Silent Channel Products Ltd
Priority date: 1979-12-04
Filing date: 1979-12-04
Publication date: 1981-06-10
Also published as: FR2471527A3; GB2063975B; ES254805U; FR2471527B3; ES254805Y

Abstract

Strip structures for trimming, sealing and like purposes, and methods of making the same, are disclosed. A woven tape (18:28) is embedded in the material of the core covering (12:22) spaced from the core elements (11:21), there being no connection between the woven tape (18:28) and the core elements (11:21) apart from the medium of the material of the core covering (12:22). The woven tape (18:28) is formed of a material having a high resistance to stretching. <IMAGE>

Description

SPECIFICATION Strip Structures for Trimming, Sealing and Like Purposes, and Methods of Making the Same This invention relates to strip structures for trimming, sealing and like purposes, and to methods of making the same.

The Complete Specification as originally published of British Patent No. 1,009,088 granted to The Standard Products Company describes and claims a generally channel-shaped strip structure for embracing engagement with and clamping retention on an edge flange or other support therefor, said strip structure including a core completely enclosed in a covering, said core including a series of individual, entirely separate spaced elements of resilient material, disposed transversely of the strip structure and extending therealong, and clamping means carried by the core covering for clamping engagement with said edge flange or other support. Such a strip structure will hereinafter be referred to as an "S.P.

structure".

Preferably, the elements in the S.P. structure are disposed in such closely spaced relation as to avoid buckling or other deformation of the cover when the structure conforms to a longitudinal or transverse curvature; more preferably, each element is in the form of a strip, with the space between adjacent elements as measured in the longitudinal direction of the strip structure being less than the width of each element as measured in the same direction. Conveniently, the elements consist of sheet metal. Part or all of the outer surface of the covering may be embossed to enhance the appearance of the S.P. structure.

In the S.P. structure, the clamping means are provided on the inner surfaces of the side walls of the core covering and comprise opposed projections for clamping engagement with the edge flange or other support on which the strip structure is to be mounted in use. The opposed projections are usually of a yieldable character, and usually extend along substantially the entire length of the strip structure.

When the S.P. structure is to serve as a sealing structure, a sealing member can be carried by the core covering externally thereof and extending therealong. Further details of, and examples of, both the aforementioned opposed projections and aforementioned sealing member are described in Specification No. 1,009,088 and are illustrated in some of the figures of the drawings accompanying that specification.

Specification No. 1,009,088 also describes and claims a method of making an S.P. structure, which method comprises covering a core strip having transversely extending portions connected along at least one side edge portion of the core strip, with a covering material; removing the or each side edge portion of the core strip, thereby to leave in the covering material separate transverse core elements; closing the side opening(s) in the covering material formed by the removal of the side edge portion(s) of the strip; and bending the covered strip into generally channel-shape.

In that method, the covering of the core strip with a covering material may be effected by extruding the covering material onto both sides of the core strip.

In one particular embodiment of the method, the transversely extending portions of the core strip include a series of resilient metal members of relatively narrow form, and the method involves providing a generally flat resilient sheet metal strip with a series of transverse slots closely spaced therealong and terminating short of the side edges of the strip, and weakening the metal strip along two longitudinal lines that intersect the transverse slots adjacent the ends thereof, after which the side edge portions of the core strip beyond the two longitudinal lines can be removed by worrying.

In another embodiment of the method disclosed in Specification No. 1,009,088, the forementioned generally flat resilient sheet metal strip is provided with a series of transverse slits closely spaced therealong and terminating short of the edges of the strip, and the slitted strip is elongated by force applied to the non-slitted side edge portions thereof, with the consequent changing of the slits into slots.

Another way of producing an S.P. structure is to form the aforementioned generally flat resilient sheet metal strip with a series of transverse slots, with small bridges between adjacent elements.

Once the core has been covered by the covering material, then preferably before the covered core is bent into a generally channel shape, the covered core is subjected to worrying in order to break the bridges, leaving the elements capable of movement independent of each other. Preferably, the covered core strip whilst still flat is passed between several pairs of rollers following a tightly curved path, which causes the bridges to break.

The S.P. structure has functioned well over a considerable number of years, but one problem has been encountered under certain circumstances. It will be appreciated that the S.P.

structure needs to be flexible in order to conform to a flange or other support structure having a longitudinal or transverse curvature. Moreover, it will be appreciated that in the S.P. structure the individual elements constituting the core are separate from each other with the consequence that, if the core covering is formed from a resiliently stretchable thermoplastic plastics material, as it is in practice, the S.P. structure can be stretched in the direction of its longitudinal axis. If, therefore, a person fitting the S.P.

structure subjects the structure to longitudinal stretching at the time of fitting, the structure, in view of the resilient nature of the covering material, will, after it has been fitted to a flange or other support, tend to creep back to its original length, with the consequence that one or both end regions of the flange may be exposed.

The Complete Specification as published of British Patent No. 1,407,412 granted to Schlegel (UK) Limited describes a wire carrier reinforcement for an edge protector strip, the reinforcement comprising a continuous length of wire bent upon itself into a zig-zag formation, to provide a plurality of U-shaped parts, and one or more high tensile strength knitted warps, into the loops of which each arm of each U of the zig-zag is held, the warps being capable of withstanding temperatures in excess of 1 800C.

The Schlegel Specification No. 1,407,412 also describes an edge protector strip comprising a length of covering material having a generally Ushaped cross-section, a wire carrier reinforcement comprised of a continuous length of wire bent into zig-zag formation to provide a plurality of Ushaped parts, and the strip being deformed so as to have a U-shaped cross-section, one or more high tensile strength knitted warps, into the loops of which each arm of each U of the zig-zag is held, the warps being capable of withstanding temperatures in excess of 1800 C, and wherein the covering material overlies the carrier, and including gripper means on the inner surface of each arm of the strip to enable the strip firmly to grip any flange edge over which it is applied. Such an edge protector strip is referred to herein after as a "Schlegel strip".

In one embodiment of the wire carrier reinforcement of the Schlegel strip, the knitting is of such construction that the knitted warps can move along each arm of each U but cannot move transversely of the yarn with the result that the spacing between adjacent arms is fixed. In view of the presence of the high tensile strength warps knitted into the wire carrier reinforcements, the degree of longitudinal stretch of the reinforcement is reduced in comparison with other known carrier reinforcements, and hence damage to the reinforcement by bending and by forming of the edge protector strip is minimised.

In the wire carrier reinforcement of the Schlegel strip, the material of the knitted warp may have a tensile strength of at least six grams/denier, at least some of the knitted warps may be of bright wire, a plurality of wire warps may be knitted into the zig-zag wire at spaced intervals, several knitted wire warps may be combined with a plurality of knitted textile warps, and the warps may be of polyethylene terephthalate.

While the wire carrier reinforcement of the Schlegel strip may contribute to the prevention of undue stretching of that strip, the production of the wire carrier reinforcement is complex in view of the need for each arm of each U of the zig-zag to be held by one of more high tensile strength knitted warps.

According to one aspect of the present invention, there is provided a generally channelshaped strip structure for embracing engagement with and clamping retention on an edge flange or other support therefor, the strip structure including a core completely enclosed in a covering, the core including a series of spaced elements of resilient material, disposed transversely of the strip structure and extending therealong; clamping means carried by the core covering for clamping engagement with the edge flange or other support; and, embedded in the material of the core covering and extending along the strip structure, a woven tape of material which is flexible and has a high resistance to stretching, the woven tape not being connected to the core elements except via the medium of the material of the core covering.

An example of a material suitable for the woven tape is glass fibre, which can be woven according to any convenient pattern into a tape of the appropriate thickness and of the appropriate width. Desirably, there should be adequate interstices between the strands of the woven tape in order that the material of the core covering on one side of the tape may form a good bond through the tape to the corresponding material on the opposite side of the woven tape.

As indicated above, the woven tape is not connected to the elements of the core, except by virtue of the medium of the material of the core covering; in one embodiment of the strip structure according to the present invention, the woven tape is spaced from the core elements, with both the woven tape and the core elements embedded in the material of the core covering; in contrast, in an alternative embodiment, those regions of the woven tape adjacent the core elements actually abut the core elements.

Conveniently, the woven tape is of such a width that it corresponds approximately to the width of the base region of the channel-shaped strip structure; also, it is convenient if the woven tape is disposed internally of the channel-shaped core elements of the strip structure, so that in use the tape is between the flange or other support, and the base region of the =ore elements; with the woven tape in this position, there is less likelihood of any distortion of the externai surface of the strip structure, as it is desirable to avoid detracting from the appearance of the strip structure.

In all other respects, the strip structure according to the present invention may, but need not, have the features of the S.P. structure. Thus, for instance, it is preferred for the elements in the strip structure according to the present invention to be disposed in such closely spaced relation as to avoid buckling or other deformation of the cover when the strip structure conforms to a longitudinal or transverse curvature; more preferably, each element of the strip structure according to the present invention is in the form of the strip, with the space between adjacent elements as measured in the longitudinal direction of the strip structure being less than the width of each element as measured in the same direction. Aiso, the elements can be formed of sheet material, and a part or all of the outer surface of the covering may be embossed to enhance the appearance of the strip structure.

When the strip structure of the present invention is similar to the S.P. structure, apart from the fact that the stip structure according to the present invention is provided with the embedded woven tape, it is preferred for the elements of the core to be individual and entirely separate from each other.

The strip structure of the present invention is not, however, limited to the case in which the core elements resemble those in the S.P.

structure. In fact,-the elements of the core of the strip structure according to the present invention can resemble the continuous length of wire bent upon itself into a zig-zag formation, as disclosed in connection with the Schlegel strip.

Another aspect of the present invention provides a method of making a generally channelshaped strip structure according to the firstmentioned aspect of the present invention, which method comprises providing the core with the covering, whilst the core and covering are generally planar; embedding in the material of the covering the woven tape while the core and covering are generally planar; and bending the covered core with the woven tape embedded in the covering into generally channel-shape.

Thus, the general technique described in the above-mentioned Patent No. 1,009,088 can be used as the basis of the method of the present invention, it being necessary to make the appropriate modification to incorporate the woven tape. In this respect, in one embodiment of the method of the present invention, a surface region of the material of the core covering is provided with longitudinally-extending ridges, and the woven tape is pressed against the ridges whilst the ridges are sufficiently hot to enter the interstices of the woven tape, whereby the woven tape becomes embedded in the material of the covering. Conveniently, but not necessarily, the ridges can be formed in the covering during extrusion of the material which constitutes the covering.The woven tape needs to be pressed against the ridges whilst they are sufficiently hot to enter the interstices of the woven tape and, for this purpose, local heating may be applied to the region of the ridges immediately upstream of a point at which the woven tape is brought to bear against the ridges; alternatively, the woven tape can be pressed against the ridges whilst the latter are still sufficiently hot from the extrusion.

In an alternative embodiment of the method of the present invention, in which the woven tape is to abut regions of the core elements, the embedding may be effected by laying the woven tape along a series of spaced elements whilst the latter are still planar, and then providing the covering by extrusion of covering material around the juxtaposed elements and woven tape.

Thereafter, the planar product can be bent so as to adopt the generally channel-shape.

As indicated above, conveniently, the woven tape is provided in the region of the base of the channel-shaped strip structure. If the woven tape is to be spaced from the core elements, the ridges can be provided solely in that region of the covering material which, once the strip structure has been curved into generally channel-shape, corresponds to the base region of the strip structure. If, in contrast, the woven tape is to abut the base region of the core elements but is to be no wider, then a tape of suitable width is chosen, which tape will obviously be less wide than the width of the core elements as measured perpendicularly to the length of the strip structure and when the latter is still in the planar condition.

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made by way of example to the accompanying drawings, in which Figure 1 is a cross-section through a known strip structure whilst still in the planar condition; Figure 2 is a cross-section through a planar strip structure provided in what is to be a base region with ridges; Figure 3 is a cross-section through a strip structure identical to that shown in Figure 2, but with a woven tape adjacent the ridges; Figure 4 is a cross-section through one embodiment of a strip structure in accordance with the present invention, in which the woven tape is spaced from the core elements, but with the strip structure still planar;; Figure 5 is a cross-secton through the strip structure shown in Figure 4 after it has been bent into generally channel-shape; Figure 6 is a cross-section through an alternative embodiment of a strip structure according to the present invention, in which the woven tape abuts the core elements but with the strip structure still in the planar condition; and Figure 7 is a plan view of one embodiment of a woven tape suitable for incorporation in a strip structure according to the present invention.

Referring first to Figure 1, there is shown, in planar condition, a strip structure similar to an S.P. structure. Around a core formed of elements 1 (only one of which is shown) is a convering generally indicated by the reference 2, which is constituted by an extrudable thermoplastic plastics material, and which is provided with four longitudinally-extending ribs 3, 4, 5 and 6, the first rib 3 being near one edge on one side of the covering and the three other ribs being near the opposite edge on the same side of the covering.

The strip structure shown in Figure 2 is similar to that shown in Figure 1, and the components indicated by the reference numerals 11 to 1 6 in Figure 2 correspond to the components indicated by the reference numerals 1 to 6 respectively in Figure 1. The sole difference between the structure of Figure 2 and that of Figure 1 is that in the former the upper side of the core covering 12 between the rib 1 3 and the rib 14 is provided with eight ridges 17 extending along the length of the strip structure. It should be noted that the strip structures shown in Figures 1 to 6 are shown as thicker than they are in reality, as certain of the components are too thin to show in their correct relative dimensions.

The strip structure shown in Figure 3 is identical to that shown in Figure 2, except that there is now positioned above the ridges 1 7 a longitudinally-extending woven tape 18 formed of strands of glass fibre.

Assuming that the ridges 1 7 of the strip structure of Figure 3 have been adequately heated, downward pressure on the woven tape 18 causes the material of the ridges 17 to move upwards through the interstices of the woven tape 18 with the result that the woven tape 18 becomes fully embedded within the material of the core covering, as shown in Figure 4, where the reference numeral 19 now indicates the upper surface of the material constituting the core covering, in which the woven tape 18 is embedded.

When the strip structure as shown in Figure 4 is bent using a conventional technique, the resulting strip structure is converted from the planar condition to the generally channel-shape shown in Figure 5.

Figure 6 shows an alternative embodiment of a strip structure according to the present invention, but in the planar condition, in which the components indicated by the reference numerals 21 to 26 correspond to the components 11 to 16 respectively of the embodiment shown in Figure 2. Also shown in Figure 6 is a woven tape 28 which, unlike the arrangement shown in Figure 4, is adjacent the core elements 21. The strip structure shown in Figure 6 can be produced by laying the woven tape 28 on a longitudinallyextending series of transverse core elements 21 and passing the resulting assembly through an extrusion die, through which it also passed the thermoplastic plastics material constituting the core covering. The strip structure shown in the planar condition in Figure 6 can, like that shown in Figure 4, be best so as to adopt the necessary generally channel-shape.

As is particularly clear from Figure 5, the woven tape in the illustrated embodiment is in the region of the base of the U of the channel-shaped strip structure. Having the woven tape only in the base region, without having it extend parallel to the upwardly directed arms of the U, provides the desired degree of resistance to longitudinal stretching of the strip structure and yet still permits adequate flexing of the strip structure so as to follow a flange or other support having a longitudinal or transverse curvature.

Figure 7 of the drawing shows a plan view of one embodiment of a woven tape suitable for use in the strip structure according to the present invention. Clearly, many other patterns of weaving will be appropriate, but generally it is desirable that certain strands of the tape extend in a direction which, when the tape is incorporated in the strip structure, is parallel to the length of the strip structure.

Figure 7B is an enlarged version of Figure 7A.

In Figure 7B it is clear that eleven strands 31 extend lengthwise and are woven with respect to a generally transverse strand 32 which, in turn, at one edge region of its travel is linked by a finer chain link strand 33.

Purely by way of illustration, a glass fibre woven tape having the following characteristics has been found to be satisfactory: Tensile strength approx 60 Ibs Extension at break approx 8% Softening point 4500C Melting point 6500C

Claims

1. A generally channel-shaped strip structure for embracing engagement with and clamping retention on an edge flange or other support therefor, the strip structure including a core completely enclosed in a covering, the core including a series of spaced elements of resilient material, disposed transversely of the strip structure and extending therealong; clamping means carried by the core covering for clamping engagement with the edge flange or other support; and, embedded in the material of the core covering and extending along the strip structure, a woven tape of material which is flexible and which has a high resistance to stretching, the woven tape not being connected to the core elements except via the medium of the material of the core covering.

2. A strip structure according to Claim 1, wherein the woven tape is formed of glass fibre.

3. A strip structure according to Claim 1 or 2, wherein the elements are disposed in such closely spaced relation as to avoid buckling or other deformation of the cover when the strip structure conforms to a longitudinal or transverse curvature.

4. A strip structure according to Claim 3, wherein each element is in the form of a strip, with the space between adjacent elements as measured in the longitudinal direction of the strip structure being less than the width of each element as measured in the same direction.

5. A strip structure according to any preceding claim, wherein the elements are formed of sheet metal.

6. A strip structure according to Claim 5, wherein the elements are individual and entirely separate from each other.

7. A strip structure according to any one of Claims 1 to 3, wherein the elements are constituted by a continuous length of wire bent upon itself into a zig-zag formation.

8. A strip structure according to any preceding claim, wherein the woven tape is spaced from the core elements.

9. A strip structure according to any one of Claims 1 to 7, wherein the woven tape abuts the core elements.

10. A strip structure according to any preceding claim, wherein the woven tape is adjacent a region of the base of the core elements when the latter are of generally channel-shaped configuration, and the tape is generally absent from the regions of the arms of the generally channel-shape.

11. A strip structure substantially as hereinbefore described with reference to, and/or as illustrated in, Figures 4 and 5, or Figure 6, of the accompanying drawings.

12. A method of making a generally channelshaped structure according to Claim 1, which comprises providing the core with the coverng, whilst the core and covering are generally planar; embedding in the material of the covering the woven tape whilst the core and covering are generally planar; and then bending the covered core with the woven tape embedded in the covering, into the generally channel-shape.

13. A method according to Claim 12, wherein a surface region of the material of the core covering is provided with iongitudinal-extending ridges and the tape is pressed against the ridges whilst the latter are sufficiently hot to enter the insterstices of the woven tape, whereby the woven tape becomes embedded in the material of the covering.

14. A method according to Claim 13, wherein the ridges are formed during the extrusion of the material constituting the covering.

1 5. A method according to Claim 13 or 14, wherein the ridges are made sufficiently hot by local heating.

16. A method according to Claim 12, wherein the embedding is effected by juxtaposing the woven tape and the series of spaced elements whilst the latter are still planar, and providing the covering by extruding the covering material around the juxtaposed elements and woven tape.

1 7. A method according to any one of Claims 12 to 16, wherein the woven tape is provided only in the region of the base of the channelshaped strip structure, internaily of the core elements.

18. A method according to any one of Claims 12 to 17, in which the strip structure being produced is in accordance with any one of Claims 2 to 10.

1 9. A method according to Claim 12 of making a generally channel-shaped structure, substantially as hereinbefore described with reference to any one or more of Figures 2 to 6, or to Figure 7, of the accompanying drawings.