CA1139514A - Heat-recoverable articles - Google Patents
Heat-recoverable articlesInfo
- Publication number
- CA1139514A CA1139514A CA000327991A CA327991A CA1139514A CA 1139514 A CA1139514 A CA 1139514A CA 000327991 A CA000327991 A CA 000327991A CA 327991 A CA327991 A CA 327991A CA 1139514 A CA1139514 A CA 1139514A
- Authority
- CA
- Canada
- Prior art keywords
- sleeve
- conductor
- solder
- article
- heat
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working
Landscapes
- Cable Accessories (AREA)
- Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
Abstract
ABSTRACT
A heat-recoverable article comprises a heat-shrinkable sleeve having an elongate electrical conductor retained therein. The conductor projects from at least one end of the sleeve and at least a portion of the length of the conductor within the sleeve is uninsulated, there being a quantity of solder, which is positioned eccentrically in the sleeve, on at least part of the said uninsulated portion Articles wherein the conductor is an earth conductor may be used to connect the earth conductor to a coaxial cable.
for example the outer conductor of a coaxial cable, inserted into the sleeve.
A heat-recoverable article comprises a heat-shrinkable sleeve having an elongate electrical conductor retained therein. The conductor projects from at least one end of the sleeve and at least a portion of the length of the conductor within the sleeve is uninsulated, there being a quantity of solder, which is positioned eccentrically in the sleeve, on at least part of the said uninsulated portion Articles wherein the conductor is an earth conductor may be used to connect the earth conductor to a coaxial cable.
for example the outer conductor of a coaxial cable, inserted into the sleeve.
Description
~3~
m is invention relates to heat-recoverable articles, more especially to heat-s~rinkable sleeves having solder therein.
It is known to make insulated soldered connections between a pair of electrical conductors by the use of a device which comprises a heat-shrinkable sleeve of insulating material which contains a ring of solder positioned at its central region. The sleeve may also be provided, at one or both ends, with a quantity of a fusible material, which melts when the sleeve is heated to cause recovery, and provides environmental sealing for the resulting connection. The fusible material may also serve to prevent escape of solder from:the end o~ the sleeve or, if there is no fusible material provided, this may be achieved by the recovery of the ends of the sleeve around the conductors, or their insulation.
Heat-shrinkable sleeves containing solder, which are described in U.S. Patent ~o. 3,243,211, have found many applications including, for example, the attachment of an earth conductor to the outer conductor of a coaxial cable.
Thus for example U.S. Specification No. 3,312,772 discloses a heat-shrinkable sleeve having a ring of solder therein and a ground lead (earth conductor) a portion of which is positioned between the solder ring and the sleeve, The ~resent invention is concerned with the provision of a heat-shrinkable sleeve containing solder, which is of use in making a connection between a first ~ .
~L3~5~
conductor, for example an earth conductor, and a second conductor, for example the outer c~nductor of a coaxial cable.
The present invéntion accordingly provides a heat-recoverable article comprising a heat-shrinkable sleeve having two open ends, the sleeve having retained therein an elongate electrical conductor, which projects from at least one end of the sleeve, at least a portion of the length of the conductor within the sleeve being uninsulated, the conductor being an earth conductor and being so positioned in the sleeve that the article can in use be positioned around an elongate substrate having external dimensions only slightly smaller than the internal dimensions of the sleeve with the substrate extending out ~5 of both ends of the sleeve, and a quantity of solder on at least-part of the said uninsulated portion, the solder being positioned eccentrically within the sleeve and being such - that it does not extend round the entire inner circumference of any cross-section of the sleeve.
The present invention further provides a heat-recoverable article comprising a heat-shrin~able sleeve having two open ends and. having a substantially constant cross-section:.throughout its length, the sleeve having retained therein adjacent to the inner surface thereof an el~ngate electrical conductor which projects from at least one end of the sleeve, at least a portion of the length of the conductor within the sleeve being uninsulated, and a ' ~ 4 --~uantity of solder on at least part of the said unin-sulated portion, the solder being positioned eccentrically within the sleeve and being such that it does not extend round the entire inner circumference of any cross-section of the sleeve.
It is not essential that the portion of the conductor outside the sleeve be insulated. Advantageousl~, however, the conductor is insulated except for a length within tne sleeve that is to take ~art in making an electrical connection.
The ~resent invention also provides a heat-recoverable article comprising a heat-shrinkable sleeve having retained therein an elongate insulated electrical conductor, which projects from at least one end of the sleeve, at least a portion of the length of the conductor within the sleeve being uninsulated, and a quantity of solder on at least part of the said uninsulated portion, - the solder being positioned eccentrically within the sleeve and being such that it does not extend round the entire inner circumference of any cross-section of the sleeve.
It is to be understood that the portion of conductor having the quantity of solder positioned thereon is not merely a tinned portion of the conductor, that is, the term "quantity of solder" is used herein to mean that in at least one cross-section through the portion of the conductor which carries the solder the amount of solder is in excess of that normally present on a pretinned conductor.
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Thus the quantity of solder should be sufficient to flow and wet a substrate to which the conductor is to be connected and to make an electrical connection between the o~nductor and the substrate. Thus there should be a co~nection-effective solder quantity. Advantageously, in at least one cross-section through the portion of the conductor which carries the solder the thickness of the solder layer on the conductor is at least as great as the radius of the conductor.
The solder may be, if desired or required, associated with an appropriate flux. The quantity of solder is advantageously localised in the sleeve in the region of the conductor, and is preferably such as to permit the insertion in the article of an elongate sub-strate having exterior dimensions only slightly smaller than the inner dimensions of the sleeve. The quantity of solder is preferably held merely by its engagement with the conductor, without the ~eed for cooperation between the conductor and any other member, for example the sleeve, although retention, or enhancement of retention, by such cooperation is not excluded and the solder may in anv case contact the sleeve, if desired.
The quantity of solder may have any suitable form and may be maintained on the conductor in any sui~able manner. Thus, for example, ~e solder may be in the form of a ball or other shape which completely surrounds a cross-section through the said portion of the conductor.
r Provided that it is firmly held thereon, however, the solder need not completely surround a cross-section through the said portion of the conductor. If desired, the quantity of solder may be provided merely by wrapping a strip of solder in an appropriate mc~nner about the conductor and, whatever the shape of the quantity of solder the latter may, if appropriate, be crimped onto the conductor. If desired or required, the quantity of solder may include one or more outwardly extending portions, for example a pair of lugs, for enhancing the enchorage of the solder, and thus the conductor, in the sleeve; during manufacture o~ ~he article the sle~ve may be partially recovered into engagement with one or more such outwardly extending portions.
The conductor a~lso is advantageously so positioned in the sleeve as to permit the insertion in the sleeve of an elongate substrate having exterior dimensions only slightly smaller than the inner dimensions of the sleeve. Pre-- ferably the portion of the conductor wikhin the sleeve extends in a direction which is su~stantially parallel to the axis of the sleeve, and advantageously the insulated portion(s) of the conductor within the sleeve a~ut(s) the inner surface of the sleeve. The article may of course comprise two or more elongate conductors, if desired.
The conductor may be retained in the sleeve in
m is invention relates to heat-recoverable articles, more especially to heat-s~rinkable sleeves having solder therein.
It is known to make insulated soldered connections between a pair of electrical conductors by the use of a device which comprises a heat-shrinkable sleeve of insulating material which contains a ring of solder positioned at its central region. The sleeve may also be provided, at one or both ends, with a quantity of a fusible material, which melts when the sleeve is heated to cause recovery, and provides environmental sealing for the resulting connection. The fusible material may also serve to prevent escape of solder from:the end o~ the sleeve or, if there is no fusible material provided, this may be achieved by the recovery of the ends of the sleeve around the conductors, or their insulation.
Heat-shrinkable sleeves containing solder, which are described in U.S. Patent ~o. 3,243,211, have found many applications including, for example, the attachment of an earth conductor to the outer conductor of a coaxial cable.
Thus for example U.S. Specification No. 3,312,772 discloses a heat-shrinkable sleeve having a ring of solder therein and a ground lead (earth conductor) a portion of which is positioned between the solder ring and the sleeve, The ~resent invention is concerned with the provision of a heat-shrinkable sleeve containing solder, which is of use in making a connection between a first ~ .
~L3~5~
conductor, for example an earth conductor, and a second conductor, for example the outer c~nductor of a coaxial cable.
The present invéntion accordingly provides a heat-recoverable article comprising a heat-shrinkable sleeve having two open ends, the sleeve having retained therein an elongate electrical conductor, which projects from at least one end of the sleeve, at least a portion of the length of the conductor within the sleeve being uninsulated, the conductor being an earth conductor and being so positioned in the sleeve that the article can in use be positioned around an elongate substrate having external dimensions only slightly smaller than the internal dimensions of the sleeve with the substrate extending out ~5 of both ends of the sleeve, and a quantity of solder on at least-part of the said uninsulated portion, the solder being positioned eccentrically within the sleeve and being such - that it does not extend round the entire inner circumference of any cross-section of the sleeve.
The present invention further provides a heat-recoverable article comprising a heat-shrin~able sleeve having two open ends and. having a substantially constant cross-section:.throughout its length, the sleeve having retained therein adjacent to the inner surface thereof an el~ngate electrical conductor which projects from at least one end of the sleeve, at least a portion of the length of the conductor within the sleeve being uninsulated, and a ' ~ 4 --~uantity of solder on at least part of the said unin-sulated portion, the solder being positioned eccentrically within the sleeve and being such that it does not extend round the entire inner circumference of any cross-section of the sleeve.
It is not essential that the portion of the conductor outside the sleeve be insulated. Advantageousl~, however, the conductor is insulated except for a length within tne sleeve that is to take ~art in making an electrical connection.
The ~resent invention also provides a heat-recoverable article comprising a heat-shrinkable sleeve having retained therein an elongate insulated electrical conductor, which projects from at least one end of the sleeve, at least a portion of the length of the conductor within the sleeve being uninsulated, and a quantity of solder on at least part of the said uninsulated portion, - the solder being positioned eccentrically within the sleeve and being such that it does not extend round the entire inner circumference of any cross-section of the sleeve.
It is to be understood that the portion of conductor having the quantity of solder positioned thereon is not merely a tinned portion of the conductor, that is, the term "quantity of solder" is used herein to mean that in at least one cross-section through the portion of the conductor which carries the solder the amount of solder is in excess of that normally present on a pretinned conductor.
~3~
Thus the quantity of solder should be sufficient to flow and wet a substrate to which the conductor is to be connected and to make an electrical connection between the o~nductor and the substrate. Thus there should be a co~nection-effective solder quantity. Advantageously, in at least one cross-section through the portion of the conductor which carries the solder the thickness of the solder layer on the conductor is at least as great as the radius of the conductor.
The solder may be, if desired or required, associated with an appropriate flux. The quantity of solder is advantageously localised in the sleeve in the region of the conductor, and is preferably such as to permit the insertion in the article of an elongate sub-strate having exterior dimensions only slightly smaller than the inner dimensions of the sleeve. The quantity of solder is preferably held merely by its engagement with the conductor, without the ~eed for cooperation between the conductor and any other member, for example the sleeve, although retention, or enhancement of retention, by such cooperation is not excluded and the solder may in anv case contact the sleeve, if desired.
The quantity of solder may have any suitable form and may be maintained on the conductor in any sui~able manner. Thus, for example, ~e solder may be in the form of a ball or other shape which completely surrounds a cross-section through the said portion of the conductor.
r Provided that it is firmly held thereon, however, the solder need not completely surround a cross-section through the said portion of the conductor. If desired, the quantity of solder may be provided merely by wrapping a strip of solder in an appropriate mc~nner about the conductor and, whatever the shape of the quantity of solder the latter may, if appropriate, be crimped onto the conductor. If desired or required, the quantity of solder may include one or more outwardly extending portions, for example a pair of lugs, for enhancing the enchorage of the solder, and thus the conductor, in the sleeve; during manufacture o~ ~he article the sle~ve may be partially recovered into engagement with one or more such outwardly extending portions.
The conductor a~lso is advantageously so positioned in the sleeve as to permit the insertion in the sleeve of an elongate substrate having exterior dimensions only slightly smaller than the inner dimensions of the sleeve. Pre-- ferably the portion of the conductor wikhin the sleeve extends in a direction which is su~stantially parallel to the axis of the sleeve, and advantageously the insulated portion(s) of the conductor within the sleeve a~ut(s) the inner surface of the sleeve. The article may of course comprise two or more elongate conductors, if desired.
The conductor may be retained in the sleeve in
2~ any suitable manner. It should be understood that provided the sleeve and conductor do not become sep~rated from one another during normal handling, it is not essential that the various components be rigidly fixed :` i "~ :
~-~ 3~
relative to each other: some slight relative movement may be permissible.
Advantageously the conduct:or is held by cooperation between the inner surface of the sleeve and the outer surface of at least one insert positioned within the sleeve.
The insert, which is preferably in the form of a ring or sleeve,may if desired be infus:ible at the temperature to which in use the article is heated to cause the sleeve to shrink and the solder to fuse, in which case it is advantageously heat-shrinkable, but it is preferably ~usible at that temperature such that on installation of the article the fused insert material may assist in prov-iding environmental sealing for the connection made.
Advantageously the conductor is held by cooperation between the sleeve and at least two inserts, at least one insert being positioned between the portion of the conductor having the quantity of solder thereon and each end of the sleeve;
in this case, the quantity of solder is not carried by the extreme end portion of the conductor. If only one insert is used the solder advantageously includes one or more outwardly extending portions for enhancing the anchorage of the solder, and thus the conductor in the sleeve.
A further method by which the conductor may be retain-ed in the sleeve comprises partial recovery o~ the sleeve about the conductor. ~his method may, if desired, be com~ined with the method described above wherein the conductor is held by one or more inserts and/or with any other methocl.
~. .
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As indicated above, the conductor is advantageously insulated except for a length thereof within the sleeve that is to take part in making an electrical connection. Advant-ageously the portion of the conductor which is to take part in making the electrical connection is not the extreme end portion, and a conduc~or which is insulated except in a region adjacent to, but not at, the end thereof is advantageously provided by incomplete removal of a short length of insulation resulting from cutting radially through the insulation at a 10 point in the region of the end of the conductor. ~hus, for example, the short length of insulation may be moved longitud-- inaliy over the conductor until a part only of the insulation extends beyond the end of the conductor, if desired the long-itudinally extending part of the short length of insulation 15 may be cut off so that the conductor and the separate length of insulation are conterminous. When the conductor is strand-ed, a short length of insulation remaining on the extreme end portion of the cQpductor may assist in maintaining the strands in the stripped portion close together and relatively straight.
20 Where the extreme end portion of the conductor is insulated and the conductor is retained in the sleeve by a pair of inserts positioned on either side of the ~uantity of solder, each insert advantageously contacts an insulated portion of the conductor. During manufacture an insulated end portion 25 of the conductor and an end of the sleeve may if desired contact a planar surface, making it possible to position the uninsulated portion of the conductor correctly without the ~L~L3~ 4 need to hold the conductor in the desired place, this is particularly advantageous when the sleeve is positioned vertically during manufacture.
The heat-shrinkable sleeve used in accordance with the invention is a sleeve at least part of which w-ll shxink on the application of heat and may ~omprise any material, advan-tageously an electrically insulating material, whi~h may be converted to or maintained in a he~t-shrinkable form. Examples of suitable materials are given in, for example, U.S. Patent 10 Specifications Nos. 3,086,242 and 3,297,819 and the other U.S.
Specifications referred to in this specification. Crosslinked polymeric materials, for example crosslinked polyvinylidene .
fluoride, are particularly suitable; Where a sleeve compris-ing two or more layers is used, the inner layer(s) need not 15 comprise the same material as the outer layer. The sleeve is advantageously sufficiently transparent to enable the soldered connection made therein to be inspected.
The sleeve may be e~truded as such, or may be formed from a sheet of material (which may if desired be heat-shrink-20 able) opposite edges of the sheet being joined in any suitablemanner, for example by the use of a peroxide. by use of a contact adhesive (for example as disclosed in U.S~ Patent No.
~-~ 3~
relative to each other: some slight relative movement may be permissible.
Advantageously the conduct:or is held by cooperation between the inner surface of the sleeve and the outer surface of at least one insert positioned within the sleeve.
The insert, which is preferably in the form of a ring or sleeve,may if desired be infus:ible at the temperature to which in use the article is heated to cause the sleeve to shrink and the solder to fuse, in which case it is advantageously heat-shrinkable, but it is preferably ~usible at that temperature such that on installation of the article the fused insert material may assist in prov-iding environmental sealing for the connection made.
Advantageously the conductor is held by cooperation between the sleeve and at least two inserts, at least one insert being positioned between the portion of the conductor having the quantity of solder thereon and each end of the sleeve;
in this case, the quantity of solder is not carried by the extreme end portion of the conductor. If only one insert is used the solder advantageously includes one or more outwardly extending portions for enhancing the anchorage of the solder, and thus the conductor in the sleeve.
A further method by which the conductor may be retain-ed in the sleeve comprises partial recovery o~ the sleeve about the conductor. ~his method may, if desired, be com~ined with the method described above wherein the conductor is held by one or more inserts and/or with any other methocl.
~. .
~:~3~
As indicated above, the conductor is advantageously insulated except for a length thereof within the sleeve that is to take part in making an electrical connection. Advant-ageously the portion of the conductor which is to take part in making the electrical connection is not the extreme end portion, and a conduc~or which is insulated except in a region adjacent to, but not at, the end thereof is advantageously provided by incomplete removal of a short length of insulation resulting from cutting radially through the insulation at a 10 point in the region of the end of the conductor. ~hus, for example, the short length of insulation may be moved longitud-- inaliy over the conductor until a part only of the insulation extends beyond the end of the conductor, if desired the long-itudinally extending part of the short length of insulation 15 may be cut off so that the conductor and the separate length of insulation are conterminous. When the conductor is strand-ed, a short length of insulation remaining on the extreme end portion of the cQpductor may assist in maintaining the strands in the stripped portion close together and relatively straight.
20 Where the extreme end portion of the conductor is insulated and the conductor is retained in the sleeve by a pair of inserts positioned on either side of the ~uantity of solder, each insert advantageously contacts an insulated portion of the conductor. During manufacture an insulated end portion 25 of the conductor and an end of the sleeve may if desired contact a planar surface, making it possible to position the uninsulated portion of the conductor correctly without the ~L~L3~ 4 need to hold the conductor in the desired place, this is particularly advantageous when the sleeve is positioned vertically during manufacture.
The heat-shrinkable sleeve used in accordance with the invention is a sleeve at least part of which w-ll shxink on the application of heat and may ~omprise any material, advan-tageously an electrically insulating material, whi~h may be converted to or maintained in a he~t-shrinkable form. Examples of suitable materials are given in, for example, U.S. Patent 10 Specifications Nos. 3,086,242 and 3,297,819 and the other U.S.
Specifications referred to in this specification. Crosslinked polymeric materials, for example crosslinked polyvinylidene .
fluoride, are particularly suitable; Where a sleeve compris-ing two or more layers is used, the inner layer(s) need not 15 comprise the same material as the outer layer. The sleeve is advantageously sufficiently transparent to enable the soldered connection made therein to be inspected.
The sleeve may be e~truded as such, or may be formed from a sheet of material (which may if desired be heat-shrink-20 able) opposite edges of the sheet being joined in any suitablemanner, for example by the use of a peroxide. by use of a contact adhesive (for example as disclosed in U.S~ Patent No.
3,770,556), or by the use of an insert comprising a thermo-plastic material and a heat-activatable crosslinking agent 25 (see for example U.S. Patent Specifications ~o. 3,891,490 and 3,927,233 and British Patent Specification ~o. 1,512,727) to form the sleeve. If desired, the opposite edges of the sheet may ~3~ f~
be provided with means for making a connection between them (see for example U.S. Specifications Nos. 3,455,336, 3,379,218, 3,530,898 and 3,574,313). Where the sleeve is formed ~rom a sheet of material, the sheet may if desired be shaped to hold the quantity of solder before forma-tion of the sleeve. Heat-shrinkability may, if necessary, be imparted to a sleeve by any su~itable method.
The heat-shrinkable sleeve may havP any desired shape. One method by which a desired shaped may be imparted comprises partial recovery of the sleeve round one or more appropriately shaped mandrels. Where one or more inserts are present, these may be fixed in the sleeve in any appropriate manner, for example, by partial recovery of the sleeve over the insert(s) to make the latter a tight fit.
The sleeve may be open at one or both ends and mav if aesired be provided with a quantity of fusible material (for example fusible polymeric material~-or other sealing material between the solder and the or _ach open end. Where the sleeve contains a fusible insert, this may form the quantity of fusible material.
The fusible material may act as Udam'' for the solder, preventing it from flowing out of the open end~s) of the sleeve during installation of the article and/or may enhance the environmental seal a'_ the end(s~ of the sleeve. Thus, the sleeve can fo_ce fused fusible ~p material into close contact with a conductor received in the open end of the sleeve to provide a reliable seal.
Alternatively, the sleeve ancl the fused fusible material could cooperate to produce a seal even at an open end that does not in use receive a substrate.
In a preferred embocliment of the invention there is provided an article comprising a heat-shrinkable sleeve having first and second open ends and having retained therein an elongate electrical conductor an insulated portion of which projects from a first open end of the sleeve and an insulated end of which is within the sleeve, a portion of the conductor between the insulated end thereof and the first end of the sleeve being uninsulated and having a quantity of solder thereon, the conductor advantageously being retained in-the sleeve by cooperation between the sleeve and first and second fusible rings the outer surface of each of which contacts an insulated portion of the conductor, ~e first ring being positioned between the uninsulated portion o~ the conductor and the first end of the sleeve and the second ring being positioned being the uninsulated portion of the conductor and the second end of the sleeve.
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The invention also provides a method of making an electrical connection which comp ises positioning an article according to the invention over a substrate and heating to cause shrinXage of the sleeve and fusing of the solder to make an electrical connection between the , electrical conductor and the substrate. Advantageously, the substrate is the outer conductor of a coaxial cable.
The article of the invention may readily be manufactur-ed without the use of complicated tooling. As the article comprises a preinstalled conducl:or and quantity of solder, the connection of an earth condllctor to, for example, the outer conductor of a coaxial cable may be effected merely by inserting the outer conductor in the article and heatin~:
the article may thus readily be installed by an automatic 10 process. Furthermore, the quantity of solder appropriate to a particular use may be selected during manufacture of the sleeve, ~nd the fact that the solder is o~ the conductor .
and positioned eccentrically in the sleeve makes it possible to obtain a very good localized solder joint without the 15 use of excess solder which may after fusing be present in undesired locations. Thus, for example, where an earth conductor is connected to the outer conductor of a coaxial cable, the use o~f the article of the invention may result in there being substantially equal amounts of solder on the 20 earth conductor and on the outer conductor in the final assembly. Furthermore, because it is necessary to fuse only the amount o solder which is required to form the joint, a smaller amount of heat is required, thus lessening the risk of overheating, for example, the sleeve, which in turn may 25 make it possihle,if desired, to use solder of a $;--~
higher melting point than would be ~ossible if for example a complete ring o~ solder were used.
Trhe above situation is in contrast to the situation in the case of, for example, a device as disclosed in U.S. Specification No. 3,312,772 which contains a complete ring of solder. In the case of such a device it has now been found that a relatively large ring of solder and hence a relatively thick sleeve is in practice required if sufficient solder is to be present at the desired location (i.e. at the point where the connection is to be made betwePn the earth corductor and the outer conductor~, so tha~ a considerable quantity of heat must be applied to ensure complete shrinking of the sleeve and fusing of the solder, with the attendant possibility of overheating. It has also now been found that the ring of solder in U.S. Specification ~o. 3,312,772 provides much more solder than is needed to connect the earth conductor with the outer conductor. This is disadvantageous, not - only because it wastes solder, but also because solder may reach locations in the completed connection where it should not be.
Various embodiments of the invention will now be described in greater detail, by way of exam~le only, with reference to the accompanying drawing in which ~igure 1 is a perspective view of one embodiment of the invention and Figures 2 to 4 are pers~ective views showing electrical conductors for use in the article of the invention having quantities of solder of different shapes thereon.
Referring now to the drawings, a heat-shrinkable sleeve 1 has open ends 2 and 3 respectively. An insulated conductor indicated generally by the reference numeral 4 having an uninsulated portion 5 within the sleeve extends from ~he open end 2 of the sleeve. The end of the conductor 4 is insula~ed by a sho~t length of insulation 6, and insulation 7 is present on the portion of the conductor 4 between the uninsulated ~ortion 5 and the open end 2 of the sleeve. A ball 8 of solder surrounds part of the uninsulated portion ~ of the conductor 4.
The portion of the conductor 4 within the sleeve 1 extends in a direction which is generally parallel to the axis of the sleeve with the portions of insulation 6 and 7 (and the solder ball 8~ contacting the inner surface of the sleeve. The conductor 4 is retained in position in the sleeve by cooperation between the sleeve and two rings of fusible material, 9 and 10 respectively. The rin~ 9-is positioned between the uninsulated portion 5 of the conductor and the open end 2 of the sleeve, a portion of insulation 7 being sandwiched between the outer surface of the ring 9 and the inner surface of the sleeve 1.
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Similarly, a portion of insulation 6 is sandwiched between the outer surface of the ring 10, which is positioned between the unin~ulated portion 5 of the conductor and the open end 3 of the sleeve, and the inner surface of t~e sleeve. The sleeve has been partially recovered from a diameter greater than that shown, to fix the conductor 4 and the rings 9 and 10 in position so that they do not mo~e significantly with respect to each other or to the sleeve 1.
In the embodiment of the invention shown in Fi~re 1, the conductor and the solder thereon are close to the inner surface of the sleeve and thus permit the insertion in the sleeve of a substrate having exterior dimensions only slightly smaller than the internal dimensions of the sleeve. Such a substrate, for example a coaxial cable having an exposed length-of outer conductor, may be inserted in the sleeve such that the said length of ~uter conductor is adjacent to solder ball 8 an~ the assembly may then be heated to cause the sleeve to shrink and ~e solder ball 8 and fusible rings 9 and 10 to ~use so that a soldered connection is made between the uninsulated portion 5 of the conductor 4 and the outer conductor of the coaxial cable and an enviromental seal is made, if desired.
When, as shown in the drawings, the sleeve 1 is transparent the soldered connection may readily be inspected, but where such visual inspection is not necessary use of a transparent material is not essential.
Figures 2 to 4 shows quant:ies of solder of different shapes on an uninsulated portio!n 5 of the conductor 4. The quantity of solder 11 shown in :Figure 2 is formed by crimp-ing a strip of solder around the portion 5, the resultantquantity of solder being in cross-section, in the form of a compressed 'C'. Thus, in a cross-section through solder 11, the centre portion 12 and end portions 13 of the solder strip contact opposite sides of the conductor, with the end portions slightly spaced from each other, and the part of the strip between the central portion and each end portion is folded on.~itself to provide a pair of diametrically opposed outwardly extending portions 14 of solder each of which has, in cross-section, a lateral ~xtent greater than the thickness of the solder strip.
Figure 3 shows a quantity of solder in the form of a ball 15 provided with a pair of diametrically opposed outwardly extending lugs 16 which may, if the sleeve is partially recovered into engagement with at least one of them, enhance the anchorage of the conductor 4 in the sleeve 1. The quantity of solder 17 shown in Figure 4 is substantially triangular in cross-section, and has a slit 18 therein whereby it is open in cross-section so that it can be forced onto the uninsulated portion 5 of the conduc-tor 4, in the case of a stranded conductor-~his step may .
be facilitat~!d by movement_. .. .... _ ~ . _ of the strands relative 'o one another. The slit 18 communicates with a central hole 19 in the solder 17, the dimensions of the hole being such that the solder ~7 is held tightly on the conductor.
The quantitie~ of solder shown in Figures 2 to
be provided with means for making a connection between them (see for example U.S. Specifications Nos. 3,455,336, 3,379,218, 3,530,898 and 3,574,313). Where the sleeve is formed ~rom a sheet of material, the sheet may if desired be shaped to hold the quantity of solder before forma-tion of the sleeve. Heat-shrinkability may, if necessary, be imparted to a sleeve by any su~itable method.
The heat-shrinkable sleeve may havP any desired shape. One method by which a desired shaped may be imparted comprises partial recovery of the sleeve round one or more appropriately shaped mandrels. Where one or more inserts are present, these may be fixed in the sleeve in any appropriate manner, for example, by partial recovery of the sleeve over the insert(s) to make the latter a tight fit.
The sleeve may be open at one or both ends and mav if aesired be provided with a quantity of fusible material (for example fusible polymeric material~-or other sealing material between the solder and the or _ach open end. Where the sleeve contains a fusible insert, this may form the quantity of fusible material.
The fusible material may act as Udam'' for the solder, preventing it from flowing out of the open end~s) of the sleeve during installation of the article and/or may enhance the environmental seal a'_ the end(s~ of the sleeve. Thus, the sleeve can fo_ce fused fusible ~p material into close contact with a conductor received in the open end of the sleeve to provide a reliable seal.
Alternatively, the sleeve ancl the fused fusible material could cooperate to produce a seal even at an open end that does not in use receive a substrate.
In a preferred embocliment of the invention there is provided an article comprising a heat-shrinkable sleeve having first and second open ends and having retained therein an elongate electrical conductor an insulated portion of which projects from a first open end of the sleeve and an insulated end of which is within the sleeve, a portion of the conductor between the insulated end thereof and the first end of the sleeve being uninsulated and having a quantity of solder thereon, the conductor advantageously being retained in-the sleeve by cooperation between the sleeve and first and second fusible rings the outer surface of each of which contacts an insulated portion of the conductor, ~e first ring being positioned between the uninsulated portion o~ the conductor and the first end of the sleeve and the second ring being positioned being the uninsulated portion of the conductor and the second end of the sleeve.
.
The invention also provides a method of making an electrical connection which comp ises positioning an article according to the invention over a substrate and heating to cause shrinXage of the sleeve and fusing of the solder to make an electrical connection between the , electrical conductor and the substrate. Advantageously, the substrate is the outer conductor of a coaxial cable.
The article of the invention may readily be manufactur-ed without the use of complicated tooling. As the article comprises a preinstalled conducl:or and quantity of solder, the connection of an earth condllctor to, for example, the outer conductor of a coaxial cable may be effected merely by inserting the outer conductor in the article and heatin~:
the article may thus readily be installed by an automatic 10 process. Furthermore, the quantity of solder appropriate to a particular use may be selected during manufacture of the sleeve, ~nd the fact that the solder is o~ the conductor .
and positioned eccentrically in the sleeve makes it possible to obtain a very good localized solder joint without the 15 use of excess solder which may after fusing be present in undesired locations. Thus, for example, where an earth conductor is connected to the outer conductor of a coaxial cable, the use o~f the article of the invention may result in there being substantially equal amounts of solder on the 20 earth conductor and on the outer conductor in the final assembly. Furthermore, because it is necessary to fuse only the amount o solder which is required to form the joint, a smaller amount of heat is required, thus lessening the risk of overheating, for example, the sleeve, which in turn may 25 make it possihle,if desired, to use solder of a $;--~
higher melting point than would be ~ossible if for example a complete ring o~ solder were used.
Trhe above situation is in contrast to the situation in the case of, for example, a device as disclosed in U.S. Specification No. 3,312,772 which contains a complete ring of solder. In the case of such a device it has now been found that a relatively large ring of solder and hence a relatively thick sleeve is in practice required if sufficient solder is to be present at the desired location (i.e. at the point where the connection is to be made betwePn the earth corductor and the outer conductor~, so tha~ a considerable quantity of heat must be applied to ensure complete shrinking of the sleeve and fusing of the solder, with the attendant possibility of overheating. It has also now been found that the ring of solder in U.S. Specification ~o. 3,312,772 provides much more solder than is needed to connect the earth conductor with the outer conductor. This is disadvantageous, not - only because it wastes solder, but also because solder may reach locations in the completed connection where it should not be.
Various embodiments of the invention will now be described in greater detail, by way of exam~le only, with reference to the accompanying drawing in which ~igure 1 is a perspective view of one embodiment of the invention and Figures 2 to 4 are pers~ective views showing electrical conductors for use in the article of the invention having quantities of solder of different shapes thereon.
Referring now to the drawings, a heat-shrinkable sleeve 1 has open ends 2 and 3 respectively. An insulated conductor indicated generally by the reference numeral 4 having an uninsulated portion 5 within the sleeve extends from ~he open end 2 of the sleeve. The end of the conductor 4 is insula~ed by a sho~t length of insulation 6, and insulation 7 is present on the portion of the conductor 4 between the uninsulated ~ortion 5 and the open end 2 of the sleeve. A ball 8 of solder surrounds part of the uninsulated portion ~ of the conductor 4.
The portion of the conductor 4 within the sleeve 1 extends in a direction which is generally parallel to the axis of the sleeve with the portions of insulation 6 and 7 (and the solder ball 8~ contacting the inner surface of the sleeve. The conductor 4 is retained in position in the sleeve by cooperation between the sleeve and two rings of fusible material, 9 and 10 respectively. The rin~ 9-is positioned between the uninsulated portion 5 of the conductor and the open end 2 of the sleeve, a portion of insulation 7 being sandwiched between the outer surface of the ring 9 and the inner surface of the sleeve 1.
,~.; ;. .
...
', . :
Similarly, a portion of insulation 6 is sandwiched between the outer surface of the ring 10, which is positioned between the unin~ulated portion 5 of the conductor and the open end 3 of the sleeve, and the inner surface of t~e sleeve. The sleeve has been partially recovered from a diameter greater than that shown, to fix the conductor 4 and the rings 9 and 10 in position so that they do not mo~e significantly with respect to each other or to the sleeve 1.
In the embodiment of the invention shown in Fi~re 1, the conductor and the solder thereon are close to the inner surface of the sleeve and thus permit the insertion in the sleeve of a substrate having exterior dimensions only slightly smaller than the internal dimensions of the sleeve. Such a substrate, for example a coaxial cable having an exposed length-of outer conductor, may be inserted in the sleeve such that the said length of ~uter conductor is adjacent to solder ball 8 an~ the assembly may then be heated to cause the sleeve to shrink and ~e solder ball 8 and fusible rings 9 and 10 to ~use so that a soldered connection is made between the uninsulated portion 5 of the conductor 4 and the outer conductor of the coaxial cable and an enviromental seal is made, if desired.
When, as shown in the drawings, the sleeve 1 is transparent the soldered connection may readily be inspected, but where such visual inspection is not necessary use of a transparent material is not essential.
Figures 2 to 4 shows quant:ies of solder of different shapes on an uninsulated portio!n 5 of the conductor 4. The quantity of solder 11 shown in :Figure 2 is formed by crimp-ing a strip of solder around the portion 5, the resultantquantity of solder being in cross-section, in the form of a compressed 'C'. Thus, in a cross-section through solder 11, the centre portion 12 and end portions 13 of the solder strip contact opposite sides of the conductor, with the end portions slightly spaced from each other, and the part of the strip between the central portion and each end portion is folded on.~itself to provide a pair of diametrically opposed outwardly extending portions 14 of solder each of which has, in cross-section, a lateral ~xtent greater than the thickness of the solder strip.
Figure 3 shows a quantity of solder in the form of a ball 15 provided with a pair of diametrically opposed outwardly extending lugs 16 which may, if the sleeve is partially recovered into engagement with at least one of them, enhance the anchorage of the conductor 4 in the sleeve 1. The quantity of solder 17 shown in Figure 4 is substantially triangular in cross-section, and has a slit 18 therein whereby it is open in cross-section so that it can be forced onto the uninsulated portion 5 of the conduc-tor 4, in the case of a stranded conductor-~his step may .
be facilitat~!d by movement_. .. .... _ ~ . _ of the strands relative 'o one another. The slit 18 communicates with a central hole 19 in the solder 17, the dimensions of the hole being such that the solder ~7 is held tightly on the conductor.
The quantitie~ of solder shown in Figures 2 to
4 may if desired be used in an article as shown in Figure 1 in place of the solder ball 8 used therein, or may be used in any o~her article constructed in accordance with the invention. One or both of the outwardly extending 1o portions 14 in Figure 2 and one or more of the apices of the triangle which is the cross-section through the qusntity of ~older 17 in Figure 4 may if desired act in the same manner as the lugs 16 in Figure 3, namely to enhance the anchorage of the solder, and hence the anchorage of the conductor ~ in the sleeve. One situation where such enhancement may be desirable is where the short length of insulation 6 in Figure 1 is absent (which may be the case if, for example the uninsulated portion of the conductor is tinned~, in which case the article may comprise only one ring of fusible material ~for example ring 9 in Figure 1, ring 10 being absent).
.
An article according to the invention may if desired comprise more than one preinstalled elongate electrical conductor having a quantity of solder thereon.
Ex~nples of elongate electrical conductors which may be used in the article of the invention are earth - 17a -conductors and electrically conductive pins, for example tenminal pins.
It is to be understo~d that a sleeve which has a substantially constant cross-section throughout its length may have an additional portioll, for example, a~ end portion, of a different cross-sectiona:L shape and/or size provided that an appreciable part of the inner circumference of the additional portion i5 spaced to a significant extent from the conductor, that is, provided the additional portion is not recoveEed into close contact with the conductor.
. .. _ . .. .. .. . . .. .... . ..... . . . .....
.
An article according to the invention may if desired comprise more than one preinstalled elongate electrical conductor having a quantity of solder thereon.
Ex~nples of elongate electrical conductors which may be used in the article of the invention are earth - 17a -conductors and electrically conductive pins, for example tenminal pins.
It is to be understo~d that a sleeve which has a substantially constant cross-section throughout its length may have an additional portioll, for example, a~ end portion, of a different cross-sectiona:L shape and/or size provided that an appreciable part of the inner circumference of the additional portion i5 spaced to a significant extent from the conductor, that is, provided the additional portion is not recoveEed into close contact with the conductor.
. .. _ . .. .. .. . . .. .... . ..... . . . .....
Claims (22)
1. A heat-recoverable article comprising a heat-shrinkable sleeve having two open ends the sleeve having retained therein an elongate electrical conductor which projects from at least one end of the sleeve at least a portion of the length of the conductor within the sleeve being uninsulated the conductor being an earth conductor and being so positioned in the sleeve that the article can in use be positioned around an elongate substrate having external dimensions only slightly smaller than the internal dimensions of the sleeve with the substrate extending out of both ends of the sleeve and a quantity of solder on at least part of the said uninsulated portion the solder being positioned eccentrically within the sleeve and being such that it does not extend round the entire inner circumference of any cross-section of the sleeve.
2. A heat-recoverable article comprising a heat-shrinkable sleeve having two open ends and having a substantially constant cross-section throughout its length the sleeve having retained therein adjacent to the inner surface thereof an elongate electrical conductor which projects from at least one end of the sleeve at least a portion of the length of the conductor within the sleeve being uninsulated and a quantity of solder on at least part of the said uninsulated portion the solder being positioned eccentrically within the sleeve and being such that it does not extend round the entire inner circumference of any cross-section of the sleeve.
3. A heat-recoverable article comprising a heat-shrinkable sleeve having retained therein an elongate insulated electrical conductor, which projects from at least one end of the sleeve, at least a portion of the length of the conductor within the sleeve being uninsulated, and a quantity of solder on at least part of the said uninsulated portion, the solder being positioned eccentrically within the sleeve and being such that it does not extend round the entire inner circumference of any cross-section of the sleeve.
4. An article as claimed in any one of claims 1 to 3, wherein the conductor is insulated except for a length within the sleeve that is to take part in making an electrical connection.
5. An article as claimed in any one of claims 1 to 3, wherein the conductor projects from one end only of the sleeve and wherein the extreme end portion of the conductor within the sleeve is insulated.
6. An article as claimed in any one of claims 1 to 3, wherein the quantity of solder is localized in the region of the conductor.
7. An article as claimed in any one of claims 1 to 3, wherein the quantity of solder is crimped onto the conductor.
8. An article as claimed in any one of claims 1 to 3, wherein the quantity of solder comprises a plurality of outwardly extending portions.
9. An article as claimed in claim 3, wherein the conductor is held by cooperation between the inner surface of the sleeve and a outer surface of at least one insert positioned within the sleeve.
10. An article as claimed in claim 9, wherein the said insert is fusible at the temperature to which in use the article is heated to cause shrinking of the sleeve and fusing of the solder.
11. An article as claimed in claim 9, wherein the insert is in the form of a ring.
12. An article as claimed in claim 9, wherein there are at least two inserts, at least one insert being positioned between the portion of the conductor having the quantity of solder thereon and each end of the sleeve.
13. An article as claimed in claim 12, wherein each insert contacts an insulated lengun of the conductor.
14. An article comprising a heat-shrinkable sleeve having first and second open ends and having retained therein an elongate electrical conductor an insulated portion of which projects from a first open end of the sleeve and an insulated end of which is within the sleeve, a portion of the conductor between the insulated end thereof and the first end of the sleeve being uninsulated and having a quantity of solder thereon.
15. An article as claimed in claim 14, wherein the conductor is retained in the sleeve by co-operation between the sleeve and first and second fusible rings the outer surface of each of which contacts an insulated portion of the conductor, the first ring being positioned between the uninsulated portion of the conductor and the first end of the sleeve and the second ring being positioned between the uninsulated portion of the conductor and the second end of the sleeve.
16. A method of making an electrical connec-tion which comprises positioning at least part of a substrate within a heat-recoverable article comprising a heat-shrink-able sleeve having retained therein an elongate insulated electrical conductor, which projects from at least one end of the sleeve, at least a portion of the length of the con-ductor within the sleeve being uninsulated, and a quantity of solder on at least part of the said uninsulated portion, the solder being positioned eccentrically within the sleeve and being such that it does not extend round the entire inner circumference of any cross-section of the sleeve, and heating to cause shrinkage of the sleeve and fusing of the solder to make an electrical connection between the conductor and the substrate.
17. A method as claimed in claim 16, wherein the substrate is the outer conductor of a coaxial cable.
18. An electrical connection which comprises an elongate insulated electrical conductor and a substrate electrically connected by means comprising a heat-shrunk sleeve and a quantity of solder within the sleeve, the connection having been made by a method which comprises in-serting at least part of the substrate within a heat-recoverable article comprising a heat-shrinkable sleeve having the elongate conductor retained therein, the conductor projecting from at least one end of the sleeve and at least a portion of the length of the conductor within the sleeve being uninsulated, and a quantity of solder on at least part of the said uninsulated portion, the solder being positioned eccentrically within the sleeve and being such that it does not extend round the entire inner circumference of any cross-section of the sleeve, and heating to cause shrinkage of the sleeve and fusing of the solder to make an electrical connection between the conductor and the substrate.
19. An article as claimed in claim 3, wherein the heat-shrinkable sleeve has two open ends.
20. An article as claimed in claim 3, wherein the electrical conductor is so positioned in the sleeve that the article can in use be positioned around an elongate substrate having external dimensions only slightly smaller than the internal dimensions of the sleeve with the substrate extending out of both ends of the sleeve.
21. An article as claimed in claim 3, wherein the heat-shrinkable sleeve has a substantially constant cross-section throughout its length.
22. An article as claimed in claim 3, wherein the elongate electrical conductor is retained in the sleeve adjacent to the inner surface thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000327991A CA1139514A (en) | 1979-05-22 | 1979-05-22 | Heat-recoverable articles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000327991A CA1139514A (en) | 1979-05-22 | 1979-05-22 | Heat-recoverable articles |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1139514A true CA1139514A (en) | 1983-01-18 |
Family
ID=4114250
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000327991A Expired CA1139514A (en) | 1979-05-22 | 1979-05-22 | Heat-recoverable articles |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1139514A (en) |
-
1979
- 1979-05-22 CA CA000327991A patent/CA1139514A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |