MXPA97003943A - He - Google Patents

Abstract

An elongate compressible seal (1) in which, in use, two ends (3) are joined by means of, at least, the connecting bolt (5) located in, and extending between, at least one opening in each end (3), wherein the or each connection bolt (5) is hollow and co-compressible and the seal (1) is therefore compressible at the junction between the two ends (

Description

SEAL The present invention relates to a seal and, in particular, to a ring seal. The seal can generally be used to seal between any two surfaces, but in particular it has utility in telecommunication cable splice covers. U.S. Patent No. 4558174 (AT &T Bell Laboratories) discloses a cover for a cable splice having two equalizing coatings and two final plate assemblies. A peripheral channel in each end plate is filled with a circumferential packing sealing between the periphery of each end plate and the surrounding coatings. The ends of each circumferential package are connected together. This is achieved by forming each circumferential package with a pair of passages extending longitudinally. At the junction of the ends of the package, bolts are placed in the passages so that they extend from one end. The other end is juxtaposed with one end and the extension pins are placed in the passages on the other end. Ring seals for cable splice closures are also known, which comprise a single elastomeric tube, the ends of which are joined by means of a solid connecting pin. An object of the present invention is to provide an elongate compressible seal in which two ends can be firmly joined, even substantially without damaging the compressibility of the seal at the joint. Another object of the invention is to provide an improved seal that is compressible, preferably, substantially uniformly compressible, along substantially its entire length. Where the seal in use is a ring seal, the seal consequently preferably is compressible about substantially all of the ring. According to the invention, an elongate compressible seal is provided in which, in use, two ends are joined by means of, at least one connecting bolt located in, and extending between, at least one opening at each end , wherein the or each connection pin is hollow and compressible and, therefore, the seal is compressible at the junction between the two ends. Preferably, the seal is hollow, i.e., hollow in addition to being hollow at each end by virtue of the or each opening. The invention has the advantage that, because the connection pin is hollow and compressible, the seal is compressible at the junction between the two ends. This is in contrast to the known tubular ring seals mentioned above, in which the ends are joined by means of a connecting bolt and consequently the seal is substantially incompressible in the joint, or at least, is significantly less compressible in the joint. union that around the rest of the seal. This generally means that with these known ring seals, there is a region of the seal that has seal characteristics significantly poorer than the rest of the seal. Furthermore, with these known ring seals, it is generally necessary, when installing the cable splice closure, to orient the ring seal so that the joint (which has poor sealing characteristics) is not located at the triple point, so-called, (ie, the point of intersection of the ring seal and the longitudinal seal of the splice closure cover). This is because the triple point is usually the location that needs the highest degree of reliability of the seals in the environmental seal of the splice closure that will be maintained. The seal of the invention can be advantageously used as a circumferential seal and / or a longitudinal seal in a cable splice closure in which said seals are in a triple point. Preferably, the seal according to the invention is resiliently compressible and / or each connection pin is resiliently compressible and advantageously, the seal is therefore resiliently compressible at the junction between the two ends. This usually has the advantage of forming the particularly reliable seal, since when the seal between two surfaces is compressed, for example, its resilience normally causes it to press against the surfaces. The seal according to the invention can advantageously be substantially uniformly compressible in use. along substantially its length. Even more advantageously, the seal can, throughout substantially its entire length, be substantially uniformly resilient for compression in use. The or each joint in the seal, when it contains the hollow compressible connection bolt (s), has, therefore, preferably, the same, or nearly the same degree of resilient compressibility. as does the rest of the seal. In some embodiments of the invention, this can be advantageously achieved by using one or more hollow compressible connection bolts that have very low resilience when compressed, e.g., substantially insignificant resilience compared to the resilience exhibited by the remainder of the seal. . The outer diameter of the connecting bolt (s) is preferably greater than the diameter of the openings at the ends of the seal in which the connecting bolt is, or the connecting bolts are located (s). This can have the advantage of allowing an airtight grip to be formed between the connecting bolt (s) and the ends of the seal. The connecting bolt is, or the bolts are, preferably an interference fit in the openings at the ends of the seal. However, additionally or alternatively, the bolt (s) and / or openings may be profiled to interlock with each other. Preferably the seal is a ring seal, e.g., a closed ring seal and preferably has a substantially annular shape in use. The seal, for example, may extend around an end block of a cable splice closure to form a seal between the end block and the cover of the closure surrounding the end block. The two ends on the seal that are joined by means of or each connecting pin, preferably are opposite ends of the same discrete elongate article. Therefore the seal is preferably an elongated seal, the two ends of which are joined to form a closed loop. However, additionally or alternatively, the two ends on the seal that are joined by means of at least one connecting pin according to the invention, may be the ends of different discrete elongated articles. The seal according to the invention may therefore comprise two or more discrete seals which are joined end to end by means of at least one connecting bolt according to the invention. For example, the seal may be a linear seal, e.g., a longitudinal seal of a cable splice closure and / or the seal may be a ring seal formed of two or more discrete seals joined together. It was mentioned before that the seal and the connecting bolt (s) are hollow. The seal and connection pin advantageously can be hollow by virtue of any suitable internal structure. The seal itself and the connecting bolt (s) may, in some embodiments, have different types of internal structure, but preferably have substantially the same type of internal structure. The seal and / or connection bolt (s) may, for example, comprise polymeric foam, either closed cell foam or open cell foam. However, in the most preferred embodiments, the seal and / or the connecting bolt (s) are not formed of polymeric foam.

The seal and / or the or each connection bolt can advantageously be tubular. When the or each connecting bolt is tubular, for example, it may be closed at one or both ends, but preferably it is open at both ends. The connecting bolt (s) can often have very little compression resilience (the advantage explained above) and / or the bolt or each bolt can hold the ends of the seal firmly. The longitudinal edges of the slit can, for example, overlap. The seal of the invention advantageously can have at least one cavity extending along substantially its entire length and the openings in which, in use, the or each connecting pin is located, preferably they are ends of the or each cavity. As mentioned before, the seal, for example, can be tubular. Preferably, the cross-sectional diameter of the or each cavity is substantially uniform along substantially the entire length of the seal. In certain preferred embodiments, the seal may be formed of sealing material and / or may have sealing material, at least, as part of an external surface thereof. A preferred sealing material is gel. The gel, for example, may comprise silicone gel, urea gel, urethane gel, thermoplastic gel or any gel or suitable geloid sealant material. Preferred gels comprise an extended oil polymer composition. Preferably the gel has a force at room temperature as determined using a Stevens-Volland Texture Analyzer of more than 45 g, particularly greater than 50 g, especially greater than 55 g, e.g., between 55 g and 60 g. Preferably it has a strain relief of less than 12%, particularly less than 10% and especially less than 8%. The tensile stress module of 100% is preferably at least 1.8 MPa, more preferably at least 2.2 MPa. In general, the compression setting is preferably less than 35%, especially less than 25%. Preferably the gel has a cone penetration measured by ASTM D217 of less than 50 (10"1 mm), more preferably at least 100 (10" 1 mm), even more preferably at least 200 (10"1 mm) and preferably not greater than 400 (10.2 mm), spatially no greater than 350 (10.1 mm) The polymer composition of the gel may comprise, for example, an elastomer, or a block copolymer having relatively hard blocks and relatively elastomeric blocks Examples of such copolymers include styrene-diene block copolymers, for example styrene-butadiene or styrene-isoprene diblock or triblock copolymers, or styrene-ethylene-butylene-styrene triblock copolymers as described in US Pat. International Patent Publication No. WO88 / 00603, however, preferably the polymer composition comprises one or more styrene-ethylene-propylene-styrene block copolymers, for example, as sold under the 'Septon' Brand by Kuraray from Japan Extender liquids used in the gel preferably comprise oils. The oils may be hydrocarbon oils, for example, paraffinic or naphthenic oils, synthetic oils, for example, paraffinic or naphthenic oils, synthetic oils, for example, polybutene or polypropene oils and mixtures thereof. The preferred oils are mixtures of non-aromatic paraffins and naphthenic hydrocarbon oils. The gel may contain additives, e.g., such as moisture scavengers (v. Gr, benzoyl chloride), antioxidants, pigments and fungicides. The seal is preferably formed, at least in part, from elastomeric material. For example, the seal may be formed of natural or synthetic rubber, or a plastic material similar to rubber. Neoprene is an example of a preferred material. As stated above, the seal according to the invention has particular utility in a splice closure of electrical or telecommunications cables. Thus, preferably the seal comprises part of a cable splice closure. The seal, for example, may comprise a ring seal which, in use, extends around an end block of the cable splice closure, e.g., between the end block and an outer cover of the closure. The closure of splices, for example, may have only one end block, but preferably has two end blocks, one on each side of the cover. According to a second aspect of the invention, a cable splice closure is provided, which includes one or more seals according to the invention. Any or all of the preferred aspects of the seal according to the first aspect of the invention may be present in the seal (s) included in the cable splice closure according to the second aspect of the invention. . The invention will now be described, by way of example, with reference to the accompanying drawings, of which: Figure 1 shows a joint region of a seal according to the invention and details of the preferred form of connection bolt for form the union; and Figure 2 shows a joining region of a similar seal according to the invention and details of another preferred form of the connection bolt for forming at the joint. Figure 1 shows a tubular seal 1, in which the two ends 3 abut to be joined by means of a tubular connection bolt 5. The connection bolt 5, comprises an open end tube which has been inserted in one of the open ends 3 in the closed ring seal, the tubular connecting pin can be inserted into the other open end 3 of the seal. Preferably, the outer diameter of the connecting bolt 5 is greater than the diameter of the openings in the ends 3 of the seal 1, causing the seal 1 to firmly grip the connecting bolt 5 and, therefore, form a firm connection. Figure 2 shows a tubular seal 1, similar to that shown in Figure 1, with a modified form of hollow connection bolt 7. This connection bolt 7, although tubular (at least in use), has a longitudinal slit 9, the longitudinal edges of which overlap. This type of connecting bolt 7 can be more compressible frequently (i.e., they can often be compressed more easily than the one shown in Figure 1) and / or can often have an increased grip on the ends of the seal 1 In this embodiment also, the outer diameter of the connecting bolt 7 is preferably larger than the diameter of the openings in the ends 3 in the seal 1.

Claims (16)

1. CLAIMS 1. An elongate compressible seal in which, in use, two ends are joined by means of at least one connecting pin located in, and extending between, at least one opening at each end, wherein the or each connection pin is hollow and compressible and the seal, therefore, is compressible at the junction between the two ends.
2. 2. A seal according to claim 1, which is hollow.
3. A seal according to claim 1 or claim 2, which is resiliently compressible and / or in which the or each connection bolt is resiliently compressible and the seal, therefore, is resiliently compressible at the junction between the two extremes.
4. 4. A seal according to any preceding claim which, in use, is a ring seal.
5. The seal according to claim 4, wherein the two ends are opposite ends of the same discrete elongate article.
6. 6. A seal according to any preceding claim, in which the, or each connection bolt is tubular.
7. A seal according to claim 6, wherein the or each connecting bolt has a longitudinal groove.
8. A seal according to claim 7, wherein the longitudinal edges of the slit overlap.
9. 9. A seal according to any preceding claim, which has at least one cavity extending along substantially its entire length and the openings in which, in use, the or each connecting pin is located, are ends of the or each cavity.
10. 10. A seal according to any preceding claim, which is tubular.
11. A seal according to any preceding claim, which has sealing material as at least part of an external surface thereof.
12. 12. A seal according to claim 11, wherein the sealing material comprises gel.
13. A seal according to any preceding claim that is formed, at least in part, from elastomeric material.
14. 14. A seal according to any preceding claim, comprising part of a cable splice closure.
15. 15. A seal according to claim 14, wherein the seal comprises a ring seal which, in use, extends around an end block of the cable splice closure.
16. 16. A cable splice closure which includes one or more seals according to any preceding claim.