JPH0135211B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to pipe fitting devices that utilize memory metals. Thermorecoverable articles, i.e. that have been transformed from a first heat-stable form to a second heat-labile form and can be returned or recovered towards said first form by the application of heat alone. It has numerous uses in various fields of articles. Such articles are typically made from polymeric materials, particularly crosslinked polymers, and are described, for example, in US Pat. Nos. 2,027,962 (Currie) and 3,086,242 (Cook et al.). It has recently been discovered that such articles can be made from certain metals often referred to as "memory metals" or "memory alloys." These metals exhibit changes in strength and morphological properties when passed through a certain transition temperature, often between the martensitic and austenitic states, and articles made from these metals , in the martensitic state and can be used to make heat recoverable articles by being deformed while in a cold state. The deformed form of the article is maintained until it is warmed above the transition temperature to become austenitic and recover to its original form. The deformation used to place the material into a thermolabile form is usually referred to as thermorecoverable plastic deformation, and in some cases can be imparted by introducing strain into the article above the transition temperature. , in which case the article assumes a deformed form upon cooling through the transition temperature. It is understood that the transition temperature may be a temperature range, and that hysteresis usually occurs so that the exact temperature at which the transition occurs depends on whether the temperature is rising or falling. Furthermore, the transition temperature is a function of variables such as the strain force applied to the material, the temperature increasing as the strain force increases, and so on. Among these memory metals, notable ones include, for example, U.S. Patent No. 3174851;
3351463, 3753700, 3759552, British Patent Nos. 1327441 and 1327442, and NASA SP5110, "55-Nitinol-Memory Alloy, etc." (U.S. Government Printing Office, Washington, DC).
There are various alloys of titanium and nickel described in C. C. 1972), the contents of which are hereby incorporated by reference. However, the heat recoverable property is not limited to such titanium-nickel alloys. Thus, for example, various Beta brass alloys exhibit this performance. For example, N. Nakanski et al.
Scripta Metallurgica 5, pages 433-440 (Pergamon Press 1971). Such materials can be doped by known techniques to lower their transition temperatures to lower temperature systems. Similarly, E. Enami et al.
On page ~68, 304 stainless steel is shown as having these properties. The contents of these descriptions are also referred to in this specification. British Patent Specifications Nos. 1327441 and 1327442 demonstrate this thermally recoverable property in a single structure useful for joining cylindrical substrates such as spaceflight hydraulics and other conduit systems. It describes how it can be used to fabricate a shrinkable member (i.e., a tubular article in which the forces of thermal recovery are directed radially inward). In the fabrication of such heat-recoverable fittings, the fittings are cooled below their transition temperature, for example by immersion in liquid nitrogen, and are dimensioned to be larger than the original internal diameter of the fitting. The fitting is expanded diametrically by pressing an outwardly tapered mandrel against the fitting. In this type of unitary thermally recoverable metal fitting, the inner surface of the fitting is machined prior to diametrical expansion so that the fitting is later thermally recovered around the tubular substrate and "etched" onto the surface of the substrate. Teeth are provided that "intrude" or otherwise deform its surface. This increases the resistance of the resulting article to tensile stresses and, in special cases, achieves a tightness of the interface between the joint and the base body (the term "tightness" is used herein). is 211Kg/cm ² of nitrogen at the interface between the joint and the base body, as seen in pipe joints.
(refers to the ability of an article pressurized to (3000 psig) to prevent the passage of more than one bubble per minute for a period of five minutes when immersed in water). A number of problems arise from providing such teeth on the inner surface of a unitary heat recoverable metal joint. First of all, this tooth is subjected to great local pressure during expansion on the mandrel, as a result of which the tooth often suffers from defects that give rise to the following conditions: That is, (a) impairing the joint's ability to form an airtight joint; (b) Decreasing the tensile strength of the joint. (c) To lower the amount of pressure that the joint can resist. Second, many metal materials that are susceptible to heat recovery are difficult to machine. Other problems arise from the unitary construction of previously used joints. For one thing, such fittings recover too quickly when placed on a warm substrate, in which case special measures are required to prevent recovery from occurring before the fitting is in its correct position on the substrate. It is necessary to use cooling equipment. Furthermore, strict quality control is required to ensure that all lubricant deposited on the inner surfaces of the fitting used to aid in expansion by the mandrel is removed prior to its use. Finally, by somewhat limiting the range of heat-recoverable materials, it is possible in some cases to find the optimal combination between the joint and the substrate material from mechanical, chemical and electrical points of view. It may be hindered. For example, this may be hindered from the viewpoints of corrosion resistance, heat shrinkability, creep resistance, sealing performance, elastic modulus compatibility, high temperature strength, and the like. The present invention comprises a heat-shrinkable member made of a memory metal and a sleeve member located inside said heat-shrinkable member, the sleeve member being a material between the device and the tubular substrate to be joined. A pipe fitting device having a configuration and/or made of materials that facilitates the formation of a stuck fitting is provided. The invention also provides a set of parts for making the above-described device, comprising a heat-shrinkable member made of memory metal and a sleeve member suitable for being placed inside the memory metal member. The invention has particular application to hollow heat-shrinkable members, particularly tubular members, made of memory metals. The term "tube" or "tubular" as used herein is not limited to hollow members of regular cylindrical shape, but also members with irregular and/or variable cross-sections, such as Y-shaped, T-shaped, and an X-shaped member. A particularly preferred member is a tubular heat-shrinkable member. In such devices, the sleeve member is an insert member that is preferably positioned coaxially within a heat-shrinkable memory metal member, such as a tubular heat-shrinkable member. , for example, a tubular insert arranged concentrically therein. The sleeve member may be formed as a single piece, such as a tube, but the present invention is not limited to such a shape; It may also be advantageous in some cases to use other shapes, such as those used in (and not limited to, circular cross-sections) and other shapes. As discussed herein below, it will be appreciated that all that is required is for the sleeve member to cover at least a substantial portion of the surface of the memory metal member, if the memory metal member does not. Otherwise, it will come into direct contact with the substrate during the joint. Preferably, the sleeve member is sized and shaped such that at least one dimension of the sleeve member changes upon recovery of the heat-shrinkable member, and the change in dimension causes the sleeve member to engage with the base body. In one of the preferred embodiments of the invention,
The sleeve member is provided with means on at least a portion of its major surface for creating a firm and preferably airtight seal between the device and the substrate upon retrieval of the device. Such means preferably consist of at least one tooth on the main surface of the sleeve member. Referring to the preferred tubular form of the device, the teeth are preferably arranged radially and more preferably circumferentially about the longitudinal axis of the sleeve member. Advantageously, the sleeve member is provided with a plurality of teeth on each side of its midpoint. However, other means may also be used to provide a good seal, for example the sleeve member may be provided with a ring of deformable material such as annealed aluminum or copper; For example, it may be coated with fluorocarbon or other polymeric materials or plated with easily deformable metal. The sleeve member is advantageously provided on each of its major surfaces with means for establishing good contact between itself and the heat-shrinkable metal member and between the coupling device and the tubular substrate. for example, each of its major surfaces may be provided with one or more teeth, and preferably each has a plurality of teeth on each side of its midpoint. provided. Advantageously, such teeth may be arranged in pairs, one formed on the outside of the sleeve member and the other formed on the inside of the sleeve member. Of course, the number of teeth,
The shape and location will vary according to the material from which the teeth and base are made and the type of interlock desired between them. In another preferred embodiment of the invention, the sleeve member has at least one weakened wall section, preferably at least a pair of weakened wall sections. For example, the weakened areas may be pores opened in the wall, or may be "thin flat areas", i.e. the thickness of the wall is partially reduced, preferably these pores and the thin flat portions are arranged parallel to the axis of the sleeve member and the pores or pairs of thin flat portions are preferably symmetrical so that relatively uniform deformation of the sleeve member in the circumferential direction occurs upon recovery. Placed. Preferably the pores and thin flat portions are equidistant from the end of the sleeve member and at least two pairs of pores or thin flat portions are provided on either side of the unweakened midpoint and equidistant from the midpoint. It is advantageous to do so. Preferably, the thin flat portion is formed on the outer surface of the sleeve member. In another preferred form of the weakened sleeve member, each of its outer surfaces tapers from a maximum wall thickness at a point adjacent its ends to a minimum wall thickness approximately at its midpoint; Preferably, the inner surface of the sleeve member is uniform. In all of the above cases it is preferred that the surface of the sleeve member is provided with a plurality of such teeth, preferably on either side of its midpoint. Alternatively or additionally, it may also be preferred to construct the insertion sleeve from a material that is susceptible to abrasion, as discussed below. In another preferred embodiment of the invention, the sleeve member is made from abrasive material, such as metal. "Abrasion" refers to a condition that arises from the affinity between metals that are easily abraded. Seizing occurs, followed by cracking, fracturing, and an increase in surface roughness. See American Society for Metals, 8th edition (1961), Metals Handbook Volume 1, page 18. (As used herein, the term "metal" means both pure metals and alloyed metals unless otherwise specified). Abrasive metals may abrade each other and other metals that are similar in hardness, surface properties, and chemistry. Particular frangible metals include titanium, aluminum, magnesium, and zirconium, and the sleeve member of the present invention can be made from such metals. A preferred sleeve member is made from commercially pure titanium, such as titanium 50A. One suitable titanium alloy is designated Ti-3Al-2.5V and is a titanium-aluminum-vanadium alloy. Preferred aluminum sleeve member is 6061
Made from aluminum series, preferably 6061T6 aluminum. Their alloys are about 1%
Magnesium, 0.6% silicon, 0.25% copper and 0.25%
Consists of chromium, as well as the remainder aluminium. Other suitable materials for the sleeve member include commercially pure zirconium, Zircaloy 2
(approx. 1.5% tin, 0.12% iron, 0.1% chromium, 0.005%
nickel, and residual zirconium), which is located in Albany, Oregon.
It is an alloy obtained from Zirconium Tech.Corp. There are also magnesium alloys, such as those obtained from Dow Chemical Corp., which
AZ 31B-F (approximately 2.5-3.5% aluminum, 0.7-
1.3% zinc, minimum 0.2% manganese, and balance magnesium) and ZK 60A−T5 (approximately 4.8−
6.2% zinc, 0.45% zirconium, and balance magnesium). For example, in some cases the sleeve member may be a simple tubular sleeve member formed from abrasive metal and there may be no contact between the sleeve member and the heat shrinkable member or between the sleeve member and the substrate. No other measures need to be provided in either case to ensure a good seal. Other means may be provided on the sleeve member (as described above) to provide a good seal, provided that such means are provided on only one of the major surfaces of the sleeve member. It is also often advantageous to make the sleeve member from a material that is susceptible to abrasion. Briefly, if the contact surfaces at either the interface between the sleeve member and the heat-shrinkable member or the interface between the sleeve member and the substrate are both substantially uniform, the sleeve member It is advantageous to make the material from a material that is susceptible to abrasion. To obtain the maximum benefit afforded by the use of abrasive materials, the surface roughness of the sleeve member should be at least as rough as the surface with which it contacts in any particular application. It is desirable that the roughness is similar to that of many other materials. For example, for the hydraulic conduit system in which the device is used, the generally uniform surface of the sleeve member is approximately 125 microinches or less;
More preferably 1.6 microns (63 microinches)
It will advantageously exhibit a profilometer roughness of: As can be appreciated from the foregoing discussion, the dimensions, configuration, and materials of the sleeve member should be selected to ensure effective operation, taking into account the characteristics of the heat-shrinkable metal member, the substrate, and the environment in which the device of the present invention is to be used. selected as obtained. Thus, while the above discussion is directed to providing teeth on the sleeve member, providing a weakened portion on the sleeve member, and forming the sleeve member from an abrasive material, respectively, given The sleeve member may combine any two or all three of these requirements, and in fact modify its operation to include alternative designs and/or materials in any application. would also be obvious. For example, the sleeve member may be provided with a coating of polymeric material or deformable metal, as described above, to facilitate the formation of an airtight seal, eg, upon deflation. Additionally, the sleeve member may be provided with teeth and/or weakened portions only in certain portions of its structure. In certain embodiments of the invention, the sleeve member is itself provided with an insert or external auxiliary member to facilitate the overall action. Special cases where this is advantageous are when the compatibility requirements between the sleeve member and the heat-shrinkable metal member differ from those between the sleeve member and the base body, or for example between two hydraulic pipe bases. As in the case of forming fluid-tight joints, each part of the sleeve member performs two different functions, such as providing proper mechanical coupling in pipes and providing corrosion resistance between pipes. This is the case when the function of forming a seal is required. Conversely, it is also suitable to provide a sleeve member having a generally smooth corrosion-resistant surface with one or more toothed sleeve members located at a distance from its midpoint. Similarly, it is also possible to provide a sleeve member having general compatibility with the heat-shrinkable metal member for the purpose of corrosion-resistant sealing and providing proper mechanical coupling with the substrate. It has been found to be advantageous in some cases. The sleeve member may be provided with a groove or other recess or otherwise shaped portion for proper positioning of another auxiliary insertion member. Additionally, the sleeve member and/or the auxiliary insert member may be resilient to facilitate secure positioning. If the sleeve member is to be provided with such a separate auxiliary insert member, it may be provided with apertures or formed into an elongated segmented sleeve member to accommodate the separate auxiliary insert member. It is advantageous to pass or be able to be inserted through said pores so as to place the pores in a defined position. However, this is not essential in all cases; it would also be possible, for example, to push the auxiliary insert member in from one end of the sleeve member. Although the present invention is particularly directed to avoiding the disadvantages that arise in certain cases when heat-shrinkable metal parts are provided with teeth, problems that sometimes arise with the provision of teeth, such as machining. Difficulties and deformations, such as tooth deformations occurring during expansion by the mandrel, are not always significant. For example, some heat shrinkable alloys are relatively easy to machine, and in some applications some tooth deformation during the deformation operation may not be significant. Furthermore, it may be even more advantageous when providing teeth in this way.
Therefore, the present invention also includes the heat-shrinkable member,
Smooth-surfaced recoverable heat-shrinkable members, including devices provided with means such as, for example, teeth on one or more of their major surfaces; It is clear that it is not limited to In preferred tubular devices of the invention, the length of the sleeve member may be greater than, equal to, or less than the length L of the heat shrinkable member. Preferably, however, the sleeve member projects from each end of the heat shrinkable member to provide strain relief adjacent the opposite end of the shrunken member. In such cases, the length of the sleeve member is preferably no greater than about L+2Di, where Di is the inner diameter of the heat-shrinkable member, and more preferably about L+Di.
Not bigger than. Preferably, the sleeve member of the device, such as the insert, is metallic. However, other materials with metal-like properties but strictly non-metallic, such as graphite, graphite-glass composites, etc., could also be used in certain applications. Suitable materials are known and their selection will be readily available to those skilled in the art. For the preferred use of the composite device of the invention for joining adjacent lengths of hydraulic tubes or other tubes made of stainless steel, titanium or aluminium, the sleeve member comprises a predominant proportion of titanium. Preferably made of metal. The base material of titanium sleeve members is stainless steel, such as 21-6-9 stainless steel (21% chromium, 6% nickel, 9%
It is particularly preferred if it is made of manganese).
If the substrate is made of a highly abrasive metal, the sleeve member can be made of a metal that is so abrasive that it will abrade if it is brought into contact with the substrate. For example, if the substrate is titanium, the sleeve member may be stainless steel. Such sleeve members are non-resilient. Preferred metals for use in heat shrinkable members include equiatomic titanium-nickel alloys, and particularly the substituted ternary alloys described in US Pat. Nos. 3,759,552 and 3,753,700. Selection of suitable dimensions for a coupling device according to the invention will be easy for those skilled in the art. However, for illustrative purposes the nominal outer diameter
The relevant dimensions of a preferred heat shrinkable fitting that may be used to join 1/2 inch tubing are shown in the table below: Variable Dimensions (inches) Heat Shrinkable Member Length 1.75 Heat Shrinkability Outer diameter of the member 0.75 Length of the sleeve member 2.0 Inner diameter of the sleeve member 0.508 Wall thickness of the sleeve member 0.036 Outer diameter of the sleeve member 0.580 Inner diameter of the heat-shrinkable member 0.534 The present invention is a heat-recoverable metal joint that has been used in the past. It is recognized that all shortcomings have been substantially overcome. Insertion of the sleeve member between the thermally recoverable member and the substrate around which the member is ultimately recovered may prevent contamination of the substrate with various residues, such as the inner surface of the compression bonding member. contamination of the substrate by lubricants often present in The combination of sleeve member and substrate material is determined for compatibility. Any teeth provided in the coupling device can be formed on the sleeve member so that they are not exposed to the destructive forces introduced during expansion with the mandrel. Since the heat-recoverable member does not need to have teeth, the manner in which it is expanded is simplified, eg bead or ball expansion can be carried out in addition to mandrel expansion. Additionally, the sleeve member of the present invention provides noticeable strain relief with the vertical grain formed upon recovery in lieu of the tapered ends conventionally provided on unitary heat shrinkable members for strain relief. protruding from the opposite end of the heat shrinkable member by an amount sufficient to This again simplifies the manufacture of the heat-shrinkable part, which can accordingly be formed from smaller machine blanks, ultimately saving expensive metal. Additionally, the sleeve member acts to insulate the cooled heat-shrinkable member from the warm substrate for a sufficient period of time to avoid unduly rapid recovery, so that conventionally used cooling devices or other techniques There will no longer be a need to rely on Similarly, although the use of teeth is particularly advantageous in many fitting devices according to the present invention, by constructing the sleeve member from abrasion-prone materials, the use of longitudinal grooves formed to resist tensile stresses may be advantageous. Emphasis must be placed on the visibility and promotion of competence. In fact, in certain cases, the resistance to tensile stresses is better if a frangible sleeve member with a uniform surface is used, which may have circles that dig into the substrate or otherwise deform it. It was discovered that this is larger than when multiple circumferential teeth are provided. Next, the present invention will be explained in detail with reference to the accompanying drawings. Referring to FIG. 1, an expandable cylindrical sleeve blank 10 is placed on a collar support 11;
This support is removably supported in an annular recess of the platform 12. The frame member 13 suspends the assembly in a suitable cryogenic liquid 14, such as liquid nitrogen, with the sleeve blank 10 completely immersed therein. A tapered expansion mandrel 15 is disposed within member 10 such that the upper portion of sleeve blank 10 engages a tapered or curved portion 16 of mandrel 15 . The front end of the push rod 17 is connected to the recess 18 at the rear end of the mandrel 15.
The rear end of the rod 17 is the front end 19 of the hydraulic ram.
It is detachably attached to the When the ram is actuated, the mandrel 15 is pushed downwards by the axial force exerted by the rod 17 and the sleeve blank 1
0 to an inner diameter equal to the maximum transverse dimension of the mandrel 15. As the blank 10 is gradually expanded by the mandrel 15, the portion of the expanded blank 10 through which the mandrel passes is slightly inflated enough to cause the outer surface of the sleeve member 20 carried by the rod 17 to engage the sleeve blank 10. There is a tendency to bounce back later. Generally, the maximum transverse dimension of the mandrel is 6-9% larger than the unexpanded inner diameter of the sleeve blank 10. After expansion, the retained diameter increase is typically on the order of 5-7%. For example, the maximum transverse dimension of the sleeve blank before expansion is
If expanded by a mandrel with an inner diameter of 0.544 inches, the expanded sleeve blank (i.e., the heat shrinkable member) will rebound after 0.013 inches as the mandrel passes through the expanded sleeve blank, and the inserted member will have an outer diameter of 0.580. Engage snugly. The push rod 17 is sized so that the sleeve member falls through the supplied heat shrink material once the mandrel 15 has passed. Of course, other means of supplying the sleeve member to the expanded sleeve blank will be apparent to those skilled in the art. For example, the sleeve member can simply be manually applied to the heat shrinkable member just before or during coupling of the substrate to the fitting. FIG. 2a shows a composite joint formed from the expansion-assembly method described with reference to FIG. 1 placed around adjacent ends of tubular substrates 21 and 22 aligned end-to-end, and FIG. Figure 2a shows the assembly resulting from recovery of the composite of Figure 2a around a substrate that has been removed. Preferably, as in each case of the illustrated heat-shrinkable member, the surface of the heat-shrinkable member that contacts the sleeve member is generally uniform, ie, substantially devoid of discrete design features such as teeth. 2a and 2b, the outer major surface of the sleeve member 20 is generally uniform and the inner major surface has a plurality of spaced apart teeth 23 which wrap around the inner intermediate portion of the fitting 20. . The thickness of the main body of the sleeve member 20 from which the teeth 23 hang is preferably thinner than the thickness of the heat-shrinkable member;
It is best to be as thin as possible in order to maximize the transfer of resilience. As can be seen in Figure 2b, the recovery of the heat shrinkable member 10 causes the teeth 23 to deform the substrates 21 and 22, increasing the resistance of the joint formed to tensile stress. As those skilled in the art will appreciate, not all shapes of peripheral teeth are suitable for forming a hermetic seal in the practice of the present invention. However, generally square teeth, such as those formed on the inner surface of the sleeve member 20 of FIG. 2a, can be advantageously used to increase resistance to gas leakage. However, knife-edge teeth are generally superior in this respect. Figures 3a and 3b illustrate another composite joint formed in accordance with the present invention before and after heat recovery around adjacent ends of end matched tubular substrates 24 and 25. Of the two major surfaces of the sleeve member 26, the inner surface is generally uniform and the outer surface has a plurality of radial teeth 27 that may or may not be formed peripherally around the entire sleeve member. As can be seen in Figure 3b, the recovery of the heat shrinkable member creates corrugations adjacent the sleeve member and base tube, which also increases the resistance of the joint formed to tensile stress. In each case of the composite joint of FIGS. 2 and 3, where the major surface of the sleeve member is generally uniform, advantages can be derived from forming the sleeve member from abrasive metal. Figures 4a and 4b illustrate another composite joint formed in accordance with the present invention before and after recovery around adjacent ends of end-aligned tubular substrates 28 and 29. In FIG. 4a, both the inner and outer major surfaces of the sleeve member 30 have radial (preferably circumferential) teeth.
Preferably, individual pairs of teeth on sleeve member 30 each project inwardly and outwardly from the sleeve member body at points equidistant from the intermediate portion to maximize the transmission of restoring forces to the base body. For example, pair 3 in Figure 4a
See teeth 1-32. Figure 4b shows the joint formed during recovery of the composite joint of Figure 4a. FIG. 5 shows the same method of manufacturing a composite joint device as in FIG. 1, except that the heat shrinkable member is formed from a sleeve blank 40 and the sleeve member 50 is made from abrasive metal. The method of procedure and relevant dimensions are otherwise the same as in FIG. FIG. 6a shows an end-to-end aligned tubular substrate 51 made from the expansion-assembly method shown in FIG.
and 52, and FIG. 6b shows the assembly resulting from recovery of the composite of FIG. 6a around a matching substrate. For the assembly of FIG. 6a, forming the sleeve member 50 from abrasive metal increases the resistance of the joint formed to tensile stress and further aids in tensile load transfer through the heat shrinkable member 40. Preferably, the surface of the heat shrinkable member in contact with the sleeve member is generally uniform, ie, substantially devoid of discrete design features such as teeth or the like. To optimally achieve the benefits afforded by the use of frangible inserts, it is desirable that the surface roughness of the sleeve member be similar to the roughness of the surface or surfaces with which it joins in a particular application. . For example, in hydraulic conduits where the use of composite fittings is preferred,
The generally uniform surface of the sleeve member is preferably approximately
It exhibits a profilometer roughness of no more than about 125 microinches (3.18 mm), most preferably no more than about 63 microinches (1.6 mm). In applications where a hermetic seal is specific, the sleeve member preferably has means on its interior surface to provide a hermetic seal between the exterior environment and the interior of the restored composite joint. 7th
In Figure a, the heat-shrinkable member 53 includes a sleeve member having an intermediate portion 55 bounded by spaced circumferential teeth 56 and 57 configured to provide a post-recovery hermetic seal around the substrate. 54 are provided. Accordingly, in FIG. 7b, the recovered heat shrinkable member 53 has teeth 56 and 5 during recovery.
7 is shown as actually cutting into tubular substrates 58 and 59. The airtightness of the finished joint can be ensured using suitably shaped teeth by deforming the base body, by deforming the teeth themselves during recovery, or by a combination of both. Of course, other methods are also possible. For example, a portion of the sleeve member on each side of the inner intermediate portion can have a ring of deformable material, such as annealed aluminum or copper, and can be coated with, for example, fluorocarbon or other polymeric material, making it easily deformable. The metal may be plated or a means may be provided to provide an airtight seal during recovery. The foregoing description has emphasized appliances in which the sleeve member has one or more teeth on one or both of its major surfaces to improve the properties of heat-recovered articles or appliances in which the sleeve member is made from abrasion-prone metals. . Figures 8a-12b now illustrate how benefits may be obtained by forming weakened wall portions in the sleeve member. This weakening facilitates selective failure of the sleeve member upon thermal recovery of the heat shrinkable member while selectively controlling the compressive force transferred to the substrate. Figures 8a and 8b illustrate another composite joint formed in accordance with the present invention before and after recovery around adjacent ends of end-aligned tubular substrates 63 and 64, respectively. Among the two main surfaces of the sleeve member 65,
The inner surface is generally uniform and the outer surface has a uniform taper with maximum thickness at points near the ends and minimum thickness near the midpoint 66, creating an hourglass shape. As can be seen in Figure 8b, recovery of the heat shrinkable member deforms the sleeve member such that it exerts a greater compressive force on the substrate at points closer to its ends than at its midpoint. This difference causes the sleeve member and base body to deform as shown in Figure 8b, increasing the resistance of the resulting joint to tensile stress. Sleeve members of the invention having weakened wall sections can also be obtained by forming one or more pores or elongated thin flat sections in the sleeve member. The thin flat portion is a region of the outer surface of the sleeve member where the wall thickness is locally reduced. Preferably, the pores and the thin flat portion are arranged parallel to the longitudinal axis of the sleeve member. Typically, at least one pair of pores or thin flat sections are used in an array so that the deformation of the sleeve member around the circumference is relatively uniform, for example due to the symmetrical arrangement. Referring to FIG. 9, a perspective view of a tubular sleeve member 72 for a composite means formed in accordance with the present invention is shown. Sleeve member 72 has a weakened wall portion defined by a pair of pores 73 whose long dimension is parallel to the longitudinal axis of the sleeve member. The midpoint of the pore corresponds to the midpoint of the sleeve member, and its ends are equidistant from the ends of the sleeve member. FIG. 10a is a perspective view of a tubular sleeve member 74 similar to FIG. 9. FIG. However, in sleeve member 74, the weakened wall portion is formed by a pair of elongated thin flattened portions 75 parallel to the longitudinal axis of the sleeve member. FIG. 10b shows a cross section of a composite joint using the sleeve member of FIG. 10 after recovery around adjacent ends of tubular substrates 76 and 77 with aligned ends. The degree of deformation has been exaggerated for purposes of illustration. As can be seen in Figure 10b, weakening the sleeve member by means of a thinner flattened section results in greater deformation in the center of the joint than would otherwise be the case. This improves the interfacial pressure between the sleeve member and the substrate, thereby improving the pressure conditions of the joint.
A joint using the sleeve member of FIG. 9 has a cross-section similar to that of FIG. 10b, if shown. FIG. 11 is a perspective view of another tubular sleeve member 78 useful in the composite joint of the present invention. Sleeve member 78 has a weakened wall portion formed by two pairs of apertures 79 located on either side of an unweakened midpoint 80 . The sleeve member 81 of FIG. 12a is the same as that of FIG. 11, except that the weakened wall sections are two pairs of elongated thin flat sections 82 disposed around an unweakened intermediate section 83. . FIG. 12b shows the twelfth column after recovery around the adjacent ends of the tubular substrates 84 and 85 with aligned ends.
Figure a shows a cross-section of a composite joint using the sleeve member of figure a; The degree of deformation has been exaggerated for purposes of illustration. 12th
As can be seen in figure b, weakening the sleeve member by means of a thin flat section results in greater deformation of the sleeve member and base body at a point intermediate between the end of the sleeve member and its unweakened intermediate portion. This deformation increases the resistance of the joint formed to tensile stress. Although the major surfaces of the sleeve members in FIGS. 9-12 are generally shown as being uniform, any
One or both sides can be provided with teeth as described below. Preferably, a plurality of teeth are provided on both sides of the intermediate portion of the sleeve member. Most preferably,
The teeth are located on the inner surface of the sleeve member. The use of teeth further improves the tensile stress resistance of the recovery joint. Alternatively, or in addition, the sleeve member can be made from abrasive materials as described above. It will be apparent to those skilled in the art that the degree to which the sleeve member is weakened will be determined by the degree to which the heat shrinkable member deforms when compressed by heat recovery. In the case of pores, the degree of weakening is determined by the number, length and width of the pores. In the case of thin flats, the number, length and width of the thin flats as well as their depth determine the degree of weakening. The following drawings show various embodiments of the invention in which the insert is provided with a combination of features as described above. In FIG. 13a, sleeve member 90 is provided with longitudinal end holes 91 on both sides of its intermediate portion 92 and is provided with internal teeth 93 to enhance the contact made by the sleeve member with the substrate. As can be seen in FIG. 13b, the tooth 93 extends over a length equal to the length of the pore 91. In the middle section 92 of the sleeve member, the inner surface is smooth for sealing purposes. Such a sleeve member can advantageously be made from Monel alloy, for example. FIG. 14 shows a similar sleeve member 94 with a plurality of apertures 95 on either side of the midsection. However, in this case the pores do not extend to the end of the sleeve member. As shown in Figure 13b, the sleeve member can be provided with a plurality of teeth near the aperture. Such a sleeve member can be made from a copper-nickel alloy, for example. The following figures further illustrate the provision of an auxiliary sleeve member. In FIG. 15a, a sleeve member 100 is shown having pores 101 similar to the sleeve members of FIGS. 13a and 14. In FIG. However, in this case the sleeve member itself is not provided with internal teeth. Instead, an auxiliary sleeve member 103 is provided as shown at 15b. 15th c.
The figure shows a cross-section of the internal shape of the sleeve member 103. The auxiliary sleeve member 103 is the sleeve member 10
It can be pushed to 0. Instead of providing an auxiliary member 103, the sleeve member 100 can be provided with a series of ring portions whose inner surfaces can be toothed or flat. These are the sleeve members 10
0 from one end or both ends. Alternatively, they are pore 10
1 and then placed into position. For this purpose, it is advantageous to enlarge one or more of the pores 101, for example as shown in pores 102 in FIG. 15a. In some cases, other auxiliary members such as member 10
3, the main sleeve member, such as sleeve member 100, can be omitted. It will be appreciated that the nature of the materials used for sleeve member 100 and other auxiliary members, such as 103, can be selected to ensure good compatibility with the driver member and substrate. In this way, for example, tooth hardness and corrosion compatibility can become independent variables in design selection. FIG. 16a shows an alternative form of sleeve member 104 with four longitudinal holes 105, one of which is widened to provide an enlarged central portion 106. FIG. FIG. 16b shows a section through this central portion and FIG. 16e shows a section through the length of the sleeve member 104, from which it will be understood that the sleeve member is provided with teeth 107 on both sides of the intermediate portion 108. Good morning. In order to provide a good seal around two adjacent pipes, for example in the region of the intermediate section, a further auxiliary sealing ring 109, for example made of a copper-nickel alloy, is attached to the sleeve member 10.
It can be located within the middle part of 4. This can be accomplished by inserting the ring 109 into the enlarged portion 106 of one of the longitudinal holes 105, then twisting the ring 90 degrees and setting it in place. The intermediate portion 108 of the sleeve member 104 may be provided with a recess 110 therein to facilitate proper positioning of the ring 109. This is the first
Shown in Figure 6d. Figure 17 shows an alternative form of sleeve member 111 with four large longitudinal pores 112 so that the sleeve member actually forms a cage. The purpose of this basket is to house auxiliary sleeve members. For example, sleeve member 11
1 can be made from a soft metal that is compatible with hydraulic fluids and can make good contact with heat-recoverable metal drivers. Alternatively, in other applications, the sleeve member 111 itself is provided with teeth (or processed to be easily worn).
It is advantageous for the central soft sealing ring to be flexible and flexible, such as ring 1 in FIG. 16c.
09 can be located in the groove 116 and held there by the spring force on the part of the sleeve member 111. Although certain sleeve members and auxiliary members have been described, it will be appreciated from the foregoing description that many other variations are possible depending on the particular application desired. The embodiments of the present invention are as follows. (1) An instrument according to the claims, wherein the pipe joint instrument is an instrument for repairing a pipe. (2) Claims in which the means for establishing a positive seal are teeth that engage or otherwise deform the surface of the tube to be joined with the sleeve member upon recovery of the heat-shrinkable member. The device described in. (3) The pipe fitting device is a device for repairing a pipe, and the means for ensuring reliable sealing is by engaging a sleeve member on the surface of the pipe to be repaired by restoring a heat-shrinkable member or 6. An appliance as claimed in claim 1, which is a tooth that otherwise deforms the surface. (4) The coupling device according to the claims, wherein the sleeve member is made of a material that is easily worn out. (5) The fitting device according to the claims, wherein the fitting device is a device for repairing a pipe, and the sleeve member is made of a material that is easily worn out. (6) A heat-shrink fitting device for joining pipe intersections (e.g., T-, a sleeve member having two arms, each arm having one open end and the other end coupled to the other arm, each arm located within a heat shrinkable memory metal member, the memory metal member A heat-shrinkable tube fitting device having a sleeve member adapted to cause the sleeve arms to contract to form a connection between the device and the tube.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view illustrating one method of manufacturing a coupling device having a multi-toothed sleeve member according to the present invention; FIG. FIG. 2b is a cross-sectional view of the fitting device of FIG. 2a after recovery; FIG. 3a is a cross-sectional view of the fitting device of FIG. 2a around the matching ends of two pipes according to the invention. FIG. 3b is a cross-sectional view of the fitting device of FIG. 3a after recovery; FIG. 4a is a cross-sectional view of the fitting device of FIG.
Figure 4 is a cross-sectional view of a third type of fitting device placed around the matching ends of two pipes according to the invention;
Fig. b is a sectional view of the fitting device of Fig. 4a after recovery; Fig. 5 is a partial sectional view illustrating a method of manufacturing a fitting device in which the sleeve member is a simple frangible tube according to the invention; Fig. 6a; 6b is a cross-sectional view of the fitting device of FIG. 6a after recovery, and FIG. 7a is a cross-sectional view of the fitting device of FIG. FIG. 7b is a cross-sectional view showing another form of heat-recoverable joint placed around the aligned ends of two pipes according to the invention, FIG.
Figure 8a is a cross-sectional view of the fitting device of Figure 8a; Figure 8a is a cross-sectional view of another type of appliance placed around the matching ends of two pipes according to the invention; Figure 8b is the cross-sectional view of Figure 8a after recovery.
Figure 9 is a perspective view of a sleeve member suitable for use in the present invention; Figure 10a is a cross-sectional view of another type of sleeve member suitable for use in the present invention; Figure 10b is a cross-sectional view of a sleeve member suitable for use in the present invention; 10a is a cross-sectional view of an instrument using the sleeve member of FIG. 10a after recovery around the aligned ends of two pipes according to the present invention; FIG. 11 is a cross-sectional view of an apparatus using the sleeve member of FIG. FIG. 12a is a cross-sectional view of an alternative sleeve member according to the present invention; FIG. 12b is a cross-sectional view of an instrument using the sleeve member of FIG. 12a according to the present invention; FIG. 13a is a cross-sectional view of an instrument for use with the present invention. 13b is a sectional view of another shaped sleeve member suitable for
Longitudinal cross-sectional view of the sleeve member of Figure 3a, No. 14
Figure 15a is a perspective view of another type of sleeve member used in the present invention, Figure 15b is a perspective view of another type of sleeve member used in the present invention, and Figure 15b is a perspective view of a sleeve member of another type used in the present invention. A perspective view of the auxiliary sleeve member, FIG. 15c is a longitudinal sectional view of FIG. 15b,
Fig. 16a is a perspective view of another type of sleeve member used in the present invention, Fig. 16b is a sectional view of an intermediate portion of Fig. 16a, and Fig. 16c is a view of an auxiliary insertion ring used in the sleeve member of Fig. 16a. Perspective view, No. 16
Figure d shows the sleeve member of Figure 16a and Figure 16c.
Figure 16e is a partial cross-sectional view showing the ring in Figure 1.
Fig. 6a is a longitudinal sectional view, Fig. 17 is a perspective view of another sleeve member used in the present invention, 10... Sleeve blank, 14... Low temperature liquid,
15... Tapered expansion mandrel, 17... Push rod, 20... Sleeve member, 21, 22... Tubular base, 23... Teeth, 24, 25... Tubular base, 2
6... Sleeve member, 27... Teeth, 28, 29...
... Tubular base body, 30 ... Sleeve member, 31, 32
... Teeth, 40 ... Sleeve blank, 50 ... Sleeve member, 51, 52 ... Tubular base, 53 ...
Heat-shrinkable member, 54...Sleeve member, 56,5
7... Teeth, 58, 59... Tubular base, 63, 64
... Tubular base body, 65 ... Sleeve member, 66 ...
Midpoint, 72... Sleeve member, 73... Pore,
74...Sleeve member, 75...Thin flat part,
76, 77... Tubular base body, 81... Sleeve member, 82... Thin flat portion, 83... Intermediate portion,
84, 85... Tubular base, 90... Sleeve member, 91... Pore, 93... Teeth, 94... Sleeve member, 95... Pore, 100... Sleeve member, 101... Pore, 102 ...Pore, 103...
... Sleeve member, 104 ... Sleeve member, 10
5...Pore, 106...Enlarged central part, 107...
Teeth, 109... Auxiliary sealing ring, 111... Sleeve member, 112... Pore, 116... Groove.

Claims (1)

[Claims] 1. A pipe fitting device comprising a heat-shrinkable member made of memory metal and a sleeve member located inside the heat-shrinkable member, wherein the sleeve member is in contact with the heat-shrinkable member, or The sleeve member is disposed in contact with the heat shrinkable member when the heat shrinkable member is contracted to form a bond between the device and the tube to be coupled, and the sleeve member is disposed on a major surface of the heat shrinkable member. A pipe fitting device, which is provided with means for establishing a reliable airtight seal between the device and the pipe to be connected.