Abstract:
A low cost crimpable and sealable contact assembly including a contact member and a tubular sleeve member. The contact member is capable of being manually continuity crimped to a tip of an electrically conductive core of an electrically insulated wire. The tubular sleeve member is then deformed to hermetically seal it to the insulation on the wire, and the contact member. The hermetic seal protects the core from corrosion. This hermetic seal is particularly important where the core comprises aluminum. Separating the crimping and sealing into separate operations permits them to be performed manually. The sleeve member may be comprised of polymeric material, or it may be metallic. The metallic embodiments may be mechanically or electromagnetically deformed. The polymeric sleeve members may, in addition, be heat shrunk.

Description:
RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/915,398, filed May 1, 2007 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates in general to methods and devices, embodiments of which include electrical contacts that are deformable into electrical continuity and hermetic sealing with an insulated wire, and, more particularly, certain embodiments of the present invention relate to electrical contact assemblies including a deformable sleeve for forming a hermetic seal between a closed barrel electrical contact and an insulated electrical wire to which the electrical contact is mounted. 
   2. Description of the Prior Art 
   Electrical contacts are conventionally provided in lieu of solder joints for purposes of providing electrical continuity between the electrically conductive core of an insulated electrical wire and an electrical bus or other device to which it is desired to attach the core. The electrically conductive cores are typically composed of some metallic material such as, for example, copper, silver, gold, aluminum, their alloys, or the like. 
   Electrical contacts often take a form in which a male or female contactor and a barrel are aligned generally axially along a common axis. The contactor is generally designed as either a male pin to be axially inserted into a socket, or a female socket into which a male pin is to be inserted. In either configuration, the purpose of engaging the male pin and the female socket is to complete an electrical circuit. The barrel has an axially extending cavity or tubular portion that provides an attachment location for the core of an insulated electrical wire. When the barrel is of the type described as a closed barrel, the electrical contact is typically gold plated and there is a small hole radially through the tubular wall of the barrel at approximately the bottom end of the closed axial cavity. This hole is required during the plating of the contact. 
   During the assembly of the electrical contact to the end of an electrical wire, the insulation is stripped from the tip of the wire to expose a short length of the electrically conductive core of the wire. The short length of exposed core is then inserted into the axial cavity in the tubular barrel of the electrical contact. The core may be either stranded or solid. The tubular wall of the barrel is typically physically crimped into electrical continuity with the bare tip of the core of the wire that is within the axial cavity. According to some previous expedients, the tubular barrel is also deformed, typically by crimping, into a hermetic seal with the insulated coating on the wire. 
   The tubular barrel of the closed barrel contact is open at the opposed end from the axially remote end of the contactor. The barrel and the contactor are typically formed in one piece aligned generally along a common longitudinal axis. The axially extending cavity that is formed by the tubular barrel is generally closed at the end nearest to the contactor with the radial hole at approximately this closed end. 
   When the wire is assembled to the electrical contact the bare tip of the core is usually inserted into the tubular barrel from the open end to substantially the full depth of the axial cavity. Previously proposed electrical contact expedients for aluminum core wire typically closed the small hole in the wall of the tubular barrel with a soft metal sleeve that was inserted into the tubular barrel during the manufacturing of the closed barrel electrical contact. The sleeve was thought to serve two purposes. It sealed this small hole and provided a soft metal to conform to the brittle aluminum core during the continuity crimp. This sleeve, however, prevents the end of the core from being visible through the hole in the wall of the barrel when the core is substantially fully inserted into the axial cavity. 
   When complex wiring harnesses are incorporated into a single installation, such as a large aircraft, that installation may include many thousands of electrical contacts. Such complex wiring harnesses are found, for example, in aircraft, military equipment, ships, space craft, and the like. Aluminum is a good electrical conductor, and it enjoys the advantage over most other metals of being comparatively lightweight. The use of aluminum core wire substantially reduces the weight of a large wiring harness as compared, for example, against copper core wire. Aluminum, however, corrodes easily, and it is much more brittle than some of the other metals such as, for example, copper or silver. 
   Where they are used, aluminum cores must be protected from corrosion to insure the reliability of the electrical connections that are made with them. Wires composed of other metals may require hermetic sealing of their cores because of exposure to corrosive environments during use. It had been previously proposed to hermetically seal the cores of wires, particularly aluminum wires, to prevent undesired corrosion. An effective hermetic seal must seal both the radial hole in the barrel of the electrical contact, and the insulation around the base of the bare tip of the core. Previously proposed sealing expedients included inserting a soft metal sleeve into the axial cavity of the barrel to cover the small opening that is at approximately the closed end of the barrel, and extending the barrel so that it surrounds the insulation that is adjacent to the bare tip of the core. The barrel is crimped at the regions of the core and the insulation for purposes of both electrical continuity and hermetic sealing, respectively. Considerable care and skill are required because there is no opportunity to directly inspect the bare tip of the core to determine whether it has been fully inserted into the axial cavity in the tubular barrel. 
   Electrical contact assemblies are often installed at the location where the wiring harness is or is to be mounted in some structure or vehicle. Such off-bench installations generally require the use of hand held tools, rather than bench mounted equipment. Such manually manipulated tools are used to accomplish the required electrical continuity crimping and hermetic sealing (crimp-sealed). The designs of prior electrical contacts that provided for hermetic sealing were such that the operation of manually powered crimp-seal tools required considerable skill and close attention to insure that a good crimp-seal was achieved. The inability to inspect the assembly to determine whether the tip of the core was fully inserted into the axial cavity in the hollow barrel made accurately assembling the contact to the wire a very critical operation. A bench mounted tool designed for performing both electrical continuity and hermetic crimping operations on previous electrical contacts is shown in Schwartzman US Pub. 2007/0039168, Published Feb. 22, 2007. 
   Typical large installations with aluminum core wire, such as large transport aircraft, use some copper core wire for particularly critical connections. As a result, at the site of the installation, there will be electrical contacts for both aluminum core and copper core wires. These contacts are not the same, and are not interchangeable. Also, the tools used to assemble the contacts to the wires are usually not the same. If a worker is not familiar with both types of contacts, or becomes confused, there is a significant risk that an electrical contact that is designed for one type of core will be assembled to a wire with a different type of core, or that the wrong tool will be used. This presents a serious safety risk. Also, the cost of inventorying and handling different types of contacts and tools for different types of cores is substantial. 
   Those skilled in the art have long recognized the need for an universal electrical contact or contact assembly for both, copper and aluminum wires that is inexpensive, and capable of being crimped by the identical crimping tool, and, when used with aluminum wire, is easily crimp-sealed by hand in off-bench assembly operations. 
   Previously proposed expedients for electrical contact systems include, for example, Peterson U.S. Pat. No. 6,814,632.  FIG. 19  of this present disclosure is based on this Peterson patent. Peterson proposes providing an adhesive seal between the barrel of an electrical contact and a nonmetallic sleeve. Electrical continuity is said to be established by a crimping process, but it is not clear how Peterson proposes to obtain a seal between the insulation of a wire and the nonmetallic sleeve. As depicted in  FIG. 19  to the present disclosure, Peterson proposes a nonmetallic sleeve  60 , which has the same internal diameter as the hollow tubular portion  62  of the contact body  64 . Sleeve  60  is adhesively joined to and extends from the hollow tubular portion  62  of the contact body. The joining is accomplished by way of an adhesive joint  66  at a joint region  68 . The inner diameter of the nonmetallic sleeve  60  is such that it is prevented from sliding over the outside of the hollow tubular portion  62  of the contact body. Instead, the sleeve is proposed as an extension of the hollow tubular portion. Peterson does not suggest any solution to the problem of hermetically sealing a hole in the hollow tubular portion  62 . It is not clear how the core  72  of wire  70  is sealed, if it is, unless the insulation on the wire is adhesively bonded to sleeve  60 . 
   Another previously proposed expedient, depicted in  FIG. 20  of the present disclosure, purports to be for use with aluminum core wire only. This approach proposes the use of a crimping operation to simultaneously form a continuity crimp between the bare tip of an aluminum core of an electrical wire and the contact body  80 , and a hermetic seal between the skirt portion  86  and the coating of insulation on an electrical wire. Skirt portion  86  is a solid part of the contact. A soft metal insert  82  is inserted into the hollow barrel of the contact. Insert  82  hermetically seals hole  84 . It also provides a soft metal interface to which the brittle aluminum core may be crimped. Insert  82  prevents direct inspection of the position of the bare tip before and after the crimping process by which electrical continuity is established between the core of the wire and the contact body. The simultaneous crimping process for both electrical continuity and hermetic sealing often requires relatively large, heavy, bench-mounted crimping devices to generate the required degree of force. 
   These and other difficulties of the prior art have been overcome according to the present invention. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention has been developed in response to the current state of the art, and in particular, in response to these and other problems and needs that have not been fully or completely solved by currently available expedients. Embodiments of the present invention effectively resolve at least the problems and shortcomings identified herein. Certain embodiments of the present invention are particularly suitable for use with aluminum core wire. 
   An embodiment of electrical contact assembly according to the present invention comprises a contact member that is crimpably deformable into electrical continuity with a bare tip portion of the core of an electrically insulated wire. The electrical continuity crimping operation is generally performed first. The embodiment includes a tubular sleeve member that slips axially over and surrounds the adjacent portions of the contact member and the insulative covering of the wire. In a subsequent operation the tubular sleeve member is deformed into hermetically sealing engagement with both the contact member and the insulative covering. The electrically conductive core of the wire is thus sealed from contact with the environment in which it is used. 
   Certain embodiments of the present invention comprise a crimpable and sealable contact assembly. The contact assembly includes a contact member and a tubular sleeve member. The contact member has an contactor portion and a barrel portion. These portions are generally aligned along a common axis between a distal end and a proximal end. The barrel portion extends from generally the proximal end toward the contactor portion. The contactor portion extends from the distal end toward the barrel portion. The barrel portion comprises a tubular member that extends generally axially from the proximal end toward the contactor portion. The tubular member has an open end at approximately the proximal end of the contact member and a closed end generally adjacent the contactor portion. The tubular member is adapted to axially receiving a bare tip of a core of a wire. The bare tip of the core is inserted axially therein from the open end of the tubular member. The core is electrically conductive and has a coating of electrical insulation thereon. The tubular member is adapted to being crimpably deformed into electrical continuity with the bare tip. 
   The tubular sleeve member is generally hollow, open at both ends, and adapted to generally axially and simultaneously receive therein an insulation covered length of the wire adjacent to the bare tip, and at least an axially extending region of the barrel portion. One of the tubular sleeve member or barrel portion includes a detent element, and the other includes a detent engaging element. The detent element is adapted to engage the detent engaging element when the insulation covered length and the axially extending region are both received within the tubular sleeve member. The tubular sleeve member is adapted to being deformable to hermetically seal the core by sealing with both the exterior surface of the barrel and the exterior surface of the insulation on the wire. 
   The tubular member and the tubular sleeve member are generally comprised of malleable material that does not significantly resiliently resist deformation. That is, the malleable material does not tend to return to its previous form when the deforming agency is removed. In certain embodiments the walls of these members are of such a thickness and material that they are deformable by manually operated hand tools. The electrical continuity function performed by the tubular member is such that it is generally required to be composed of malleable electrically conductive metal, such as, for example, copper, silver, alloys thereof, and the like. Such materials, and their physical and electrically conductive properties are well known to those skilled in the art. The tubular sleeve member need not be electrically conductive, but it must be deformable into hermetically sealing engagement with both the insulative covering on the wire and the tubular member. It may be comprised of the same malleable metals as the tubular member, or it may be comprised of other metals or deformable organic or inorganic polymeric material. Suitable materials are, for example, adapted to being crimped, shrunk, or compressed into hermetically sealing engagement with the external surfaces of the tubular member and the surface of the coating of electrical insulation on the wire. Heat shrinkable organic or inorganic polymeric materials are well known, and such materials are well suited for use according to the present invention. 
   Embodiments generally avoid the use of any sealing or adhesive material other than the material of the tubular sleeve member and tubular members. Such additional sealing or adhesive materials require controlled application procedures, the inventorying, providing and application of an additional material, all of which increases the complexity of the operations by which the contact assembly is assembled. Also, the characteristics of the components should be such that no surface treatment steps are required to accomplish the desired sealing. Such surface preparation steps include, for example, physically or chemically roughening, smoothing or otherwise modifying the mutually engaging surfaces. The capacity to seal without the use of such extra treatment steps, sealants or adhesives is generally a factor in selecting the materials from which the tubular sleeve member, tubular member, and insulative covering are selected for a particular assembly. Further, in certain embodiments specific materials are selected from amongst the available alternatives specifically for their compatibility with one another. 
   The tubular sleeve member and mating surfaces of the insulation and tubular member in some embodiments are generally cylindrical. Other configurations are possible, but optimal sealing and ease of operation are often best achieved with generally cylindrical mating surfaces on mating components. 
   Certain embodiments, particularly those involving a some what brittle core, such as aluminum, include a crimp cushioning region that is adapted to being crimpably deformed into electrical continuity with the bare tip of a brittle core. The crimp cushioning region may take the form of, for example, a soft metal insert inside of the tubular member in the region where the crimping deformation occurs. When crimped, the inside surface of the soft metal insert directly engages and conforms to the brittle core without cracking it. The outside surface of the insert directly engages the inside surface of the tubular member. Electrical continuity is thus established from the core to the insert, to the tubular member of the barrel portion, to the tubular sleeve member (in embodiments where the tubular sleeve member is electrically conductive) and to a contactor portion of the contact member. Such soft metal inserts include, for example, a fully annealed generally cylindrical hollow copper or silver insert, or the like. The insert is fixed in a desired location within the tubular member, for example, by friction. For example, inserting a relatively cold insert into a relatively hot tubular member allows the insert to slide into the relatively enlarged tubular member. When the two components reach approximately the same temperature the tubular member shrinks into a tight fit around the insert, which holds the insert in the desired location relative to the tubular member. Such a shrink fit is accomplished, for example, by an operation that is sometimes described as “sweating” the parts together. Also, the parts may be press fit together in a pressing operation. Embodiments with such a soft metal insert employ an insert that does not reach the full length of the axial cavity in the barrel. Thus, the generally radial hole through the barrel portion near the closed end of the tubular member is not blocked by the insert. 
   The generally radial hole through the tubular member serves as an inspection hole that is adapted to being inspectingly associated with the bare tip of the core when that bare tip is substantially fully inserted to approximately the closed end of the tubular member. When the core is inserted for substantially the full length of the axial cavity, a spot on the bare tip of the core is visible through the inspection hole. It is thus possible to quickly and accurately visually check whether the bare tip of the core has been fully inserted into the barrel both before and after the continuity crimping step has been accomplished. If the bare tip is visible it indicates that the core is in the correct location in the barrel portion. Generally, the correct position is when the bare tip is fully inserted to the full depth of the tubular member, although other configurations may be desired for the purposes of a particular installation. In such other configurations an inspection hole may be positioned along the axially length of the tubular member at a desired location. 
   In certain embodiments the sleeve member comprises substantially transparent organic or inorganic polymeric material. In some such embodiments the substantially transparent polymeric material is adapted to being deformed by heat-shrinking into hermetically sealed engagement with the tubular member and the insulation on the wire. This hermetically seals the core. When the contact assembly is fully assembled to the wire, the substantially transparent polymeric material permits the bare tip of the core to be visually inspected through the inspection hole in the tubular member. 
   A detent engaging element and a detent element are provided in certain embodiments as a positioning aid during the assembly of the contact assembly. According to certain embodiments, these elements are engaged after continuity crimping has occurred. The engagement of these elements holds the tubular sleeve member at a desired location relative to the tubular member as the sleeve deformation step is initiated. A worker can feel and/or hear when these two elements engage with one another. By pulling on the contact member and the tubular sleeve member in a direction to disengage them a worker can determine whether the detent and detent engaging elements are still engaged. This quick and easy check, after the wire is manipulated to a new position for some purpose, allows a worker to determine that the components are properly positioned prior to initiating a sealing crimp. This tactile or audible clue permits a worker to proceed quickly to the tubular sleeve member deformation step with confidence that the tubular sleeve member is properly positioned, and will remain properly positioned during the tubular sleeve member deforming step. According to some embodiments, for example, the detent engaging element comprises a generally circumferential groove in the tubular member or the tubular sleeve member, and the detent element comprises one or more protrusions on the other member. Such protrusions are adapted to engage the generally circumferential groove. 
   The contact assembly is assembled to a wire by selecting a contact member that has a contactor portion and a barrel portion. The barrel portion generally extends from a proximal end of the contact member towards the contactor portion. The contactor portion generally extends from the distal end of the contact member towards the barrel portion. The barrel portion comprising a tubular member that extends generally axially from the proximal end toward the contactor portion. The tubular member has an open end at approximately the proximal end. A bare tip of a core of the wire is inserted axially into the tubular member from its open end. The core is electrically conductive and has a coating or covering of electrical insulation thereon. The tubular member is crimpably deformed into electrical continuity with the bare tip. In embodiments, the continuity crimped assembly is checked to determine that a spot on the tip of the core is visible through the inspection hole. A generally tubular sleeve member is provided generally around an insulation covered length of the wire adjacent to the bare tip of the core, and at least an axially extending region of the barrel portion. According to certain embodiments, one of the tubular sleeve member and barrel portion includes a detent element and the other includes a detent engaging element. The generally tubular sleeve member is slipped axially over the barrel portion of the continuity crimped assembly to a location where the detent element and detent engaging element are engaged with one another. The tubular sleeve member is then deformed to hermetically seal the core. 
   According to certain embodiments, the physical characteristics of the deformable materials are such that the deforming steps are performed manually. That is, the tools that are used are powered only by the worker&#39;s hands rather than by some external power source. 
   In those embodiments wherein the hollow tube member includes an inspection hole therethrough and the sleeve member comprising substantially transparent polymeric material, it is possible to perform a quality control operation by checking to see if the bare tip of the core is visible through the deformed sleeve member. 
   To acquaint persons skilled in the pertinent arts most closely related to the present invention, an embodiment of a contact assembly that illustrates a best mode now contemplated for putting the invention into practice is described herein by, and with reference to, the annexed drawings that form a part of the specification. The exemplary contact assembly is described in detail without attempting to show all of the various forms and modifications in which the invention might be embodied. As such, the embodiments shown and described herein are illustrative, and as will become apparent to those skilled in the arts, can be modified in numerous ways within the scope and spirit of the invention, the invention being measured by the appended claims and not by the details of the specification or drawings. 
   Other objects, advantages, and novel features of the present invention will become more fully apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings, or may be learned by the practice of the invention as set forth herein. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention provides its benefits across a broad spectrum. While the description which follows hereinafter is meant to be representative of a number of such applications, it is not exhaustive. As those skilled in the art will recognize, the basic apparatus taught herein can be readily adapted to many uses. This specification and the claims appended hereto should be accorded a breadth in keeping with the scope and spirit of the invention being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed. 
     Referring particularly to the drawings for the purposes of illustrating the invention and its presently understood best mode only and not limitation: 
       FIG. 1  is a top view of an unassembled crimpable and sealable contact assembly, in assemblable relationship with an electrically insulated wire, wherein a section of insulation has been stripped from an electrically conductive core of the wire to form a bare tip, and a sleeve member of the contact assembly has been inserted over the insulation of the wire adjacent to the bare tip. 
       FIG. 2  is a top view of the embodiment of  FIG. 1  illustrating a partially assembled configuration in which the bare tip of the core has been fully inserted into a hollow tube member in the barrel portion of the contact member. 
       FIG. 3  is a top view of the embodiment of  FIGS. 1-2  illustrating a partially assembled configuration in which the hollow tube member has been crimpably deformed into electrical continuity with the bare tip of the core, and a spot on the core near its end is visible through the inspection hole. 
       FIG. 4  is a top view of the embodiment of  FIGS. 1-3  illustrating a partially assembled configuration in which the sleeve member has been slipped axially over the exterior of the crimpably deformed hollow tube member, and a detent member has been engaged by a detent engaging member between the barrel portion and the sleeve member to hold the sleeve member in position relative to the barrel portion for final assembly. 
       FIG. 5  is a top view of the embodiment of  FIGS. 1-4  illustrating a fully assembled configuration in which the sleeve member has been deformed to fully encapsulate and hermetically seal the crimped barrel and the end of the insulation so that the core is hermetically sealed from the environment. 
       FIG. 6  is a view of the embodiment of  FIG. 1  partially in elevation and partially in section taken along line  6 - 6  in  FIG. 1  with the components of the contact assembly shown in cross-section. 
       FIG. 7  is a side view of the partially assembled configuration of  FIG. 2  partially in elevation and partially in section taken along line  7 - 7  in  FIG. 2  with the components of the contact assembly shown in cross-section. 
       FIG. 8  is a side view of the partially assembled configuration of  FIG. 3  partially in elevation and partially in section taken along line  8 - 8  in  FIG. 3  with the components of the contact assembly shown in cross-section. 
       FIG. 9  is a side view of the partially assembled configuration of  FIG. 4  partially in elevation and partially in section taken along line  9 - 9  in  FIG. 4  with the components of the contact assembly shown in cross-section with a detent element and a detent engaging element interengaged to secure the sleeve member in position relative to the barrel portion for the final assembly step. 
       FIG. 10  is a side view of the partially assembled configuration of  FIG. 5  partially in elevation and partially in section taken along line  10 - 10  in  FIG. 5  with the components of the contact assembly shown in cross-section. 
       FIG. 11  is a top view of an embodiment in a partially assembled configuration similar to that illustrated in  FIG. 3  wherein the sleeve member is comprised of a substantially transparent heat shrinkable polymeric material, and the axially outer end of the bare tip of the core is visible through an inspection hole. 
       FIG. 12  is a top view of an embodiment in a partially assembled configuration similar to that illustrated in  FIG. 4  wherein the bare tip is visible through the substantially transparent sleeve member of  FIG. 11 . 
       FIG. 13  is a top view of an embodiment in a fully assembled configuration similar to that illustrated in  FIG. 5  wherein the bare tip is visible through the substantially transparent sleeve member of  FIG. 11 . 
       FIG. 14  is a side view partially in elevation and partially in section of a further embodiment with the components of the contact assembly in cross-section wherein the detent element and detent engaging element are located substantially adjacent the proximal end of a shoulderless contact member, and an electrical continuity crimp operation has been performed, but a sealing operation has not. 
       FIG. 15  is an enlarged partial cross-sectional view taken along line  15  in  FIG. 9  illustrating the engagement of the detent element and detent engaging element of the embodiment of  FIG. 9 . 
       FIG. 16  is an enlarged partial cross-sectional view taken along line  16  in  FIG. 12  illustrating the engagement of the detent element and detent engaging element of the embodiment of  FIG. 12 . 
       FIG. 17  is an enlarged partial cross-sectional view taken along line  17  in  FIG. 14  illustrating the engagement of the detent element and detent engaging element of the embodiment of  FIG. 9 . 
       FIG. 18  is a cross-sectional view of an embodiment with a crimp cushioning region positioned within the hollow tube member of the barrel portion. 
       FIG. 19  is a cross-sectional view of a prior art electrical contact embodiment. 
       FIG. 20  is a cross-sectional view of a second prior art electrical contact embodiment. 
       FIG. 21  is a side view of an assembled configuration partially in elevation and partially in section with the components of the contact assembly shown in cross-section wherein the contactor portion is a female socket. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings wherein like reference numerals designate identical or corresponding parts throughout the several views. It is to be understood that the drawings are diagrammatic and schematic representations of various embodiments of the invention, and are not to be construed as limiting the invention in any way. The use of words and phrases herein with reference to specific embodiments is not intended to limit the meanings of such words and phrases to those specific embodiments. Words and phrases herein are intended to have their ordinary meanings, unless a specific definition is set forth at length herein. 
   Referring particularly to the drawings, there is illustrated generally at  20  in  FIG. 1  an exploded view including a crimpable and sealable contact assembly generally in alignment with an electrically insulated wire  38 . The contact assembly includes an electrical contact member  20  and a barrel portion  24  that are generally aligned along a common axis between a distal end  26  and a proximal end  28 . A tubular sleeve member  40  is illustrated in an unassembled configuration generally axially aligned with but separated from barrel portion  24 . Tubular sleeve member  40  as shown, for example,  FIGS. 1 and 6  is slidably and axially received over the insulation adjacent to a bare tip  34  of a core  36 . The barrel portion  24  extends from the proximal end  28  toward a contactor portion  22 . The contactor portion  22  extends from the distal end  26  toward the barrel portion  24 . In the embodiment chosen for illustration in, for example,  FIGS. 1 ,  6 , and  18 , a shoulder member  25  is located generally at the junction between the barrel and electrical contact portions. The barrel portion  24  comprises a tubular member  30 , which extends generally axially from the proximal end  28  toward the contactor portion  22 . The contactor portion may be either a male pin or a female socket such as that illustrated at  88  in  FIG. 21 . 
   Turning now to  FIG. 6 , which depicts a partial cross-section of the exploded assembly depicted in  FIG. 1 , the tubular member  30  has an open end  32  at approximately the proximal end  28 , and is adapted to axially receive a bare tip  34  of a core of a wire  36  inserted axially therein from the open end  32 . In the embodiment chosen for purposes of illustration, the barrel portion is hollow from the proximal end to approximately the electrical contact portion, and the core  36  is a solid core. The core  36  of wire  38  is electrically conductive and has a covering of electrical insulation thereon. The covering of electrical insulation is generally cut so that cut surface  39  will mate with proximal end  28  when the bare tip  34  is fully inserted into tubular member  30 . The cut surface  39  is typically perpendicular to the longitudinal axis of the wire and forms the end of a right cylindrical covering of insulation on the core  36 . The tubular member  30  is adapted to being crimpably deformed into electrical continuity with the bare tip  34 . In certain embodiments the characteristics of the barrel and the core allow for the use of a lightweight, manually held crimping tool for forming the electrical continuity crimp between the barrel and the core. 
   As illustrated, for example, in  FIGS. 7 through 10 , the crimp seal assembly process includes the steps of inserting the end  45  of bare tip  34  fully into tubular member  30  ( FIG. 7 ). Next, tubular member  30  is crimped as indicated at  31 , for example, by the application of mechanical or electromagnetic force, into electrical continuity with bare tip  34  ( FIG. 8 ). Tubular sleeve member  40  is then slipped axially into a configuration where it surrounds both insulation covered length  33  of the wire and the barrel portion  24  including the region where hole  54  is located. In this configuration the detent and detent engaging elements are interengaged to hold tubular sleeve member  40  in position for the sealing operation to be performed ( FIG. 9 ). Tubular sleeve member  40  is then sealingly deformed into hermetic sealing engagement with the adjacent exterior surfaces of contact member  20  and the insulated wire. The core  36  is thus hermetically sealed ( FIG. 10 ). 
   Tubular sleeve member  40 , which is generally hollow and open at both ends, is adapted to generally axially and simultaneously receive therein an insulation covered length of wire  33  adjacent bare tip  34 , and at least an axially extending region of the barrel portion  24 . The cross-section of the sleeve member can take on numerous shapes as may be required to accommodate the barrel portion and the insulation covering on the wire, including a circular cross-section resulting in a cylindrical sleeve member. When tubular sleeve member  40  has been deformed into sealing engagement with insulation covered length  33 , a section  43  ( FIG. 10 ) of tubular sleeve member  40  is drawn down into hermetically sealing engagement with the exterior surface of the electrical insulation. A barrel sealing portion  41  of tubular sleeve member  40  is drawn down into a hermetic seal with an exterior surface of barrel portion  24 . The axially inner end portion  58  of tubular sleeve member  40  is deformed down into groove  56  as illustrated at  59  in  FIG. 10 . 
   One of tubular sleeve member  40  and barrel portion  24  includes a detent element, for example,  46 , and the other of the sleeve member  40  and barrel portion  24  includes a detent engaging element, for example,  48 . For example, referring to  FIG. 1 , the detent element  46  may comprise one or more dimples formed in the sleeve prior to commencement of the assembly process, and the detent engagement element  48  may comprise a generally circumferential groove  56  formed in the barrel portion prior to commencement of the assembly process. The detent element  46  is adapted to engage the generally circumferential groove  56  portion of detent engaging element  48  when the insulation covered length  33  and the axially extending section of the barrel portion  24  are received in the tubular sleeve member  40 . Further, the detent element and detent engaging element may be positioned at one or more of various locations along the barrel portion  24 . For example,  FIG. 15  and  FIG. 16  are close-up views of the detent element and detent engaging element for the embodiments of  FIG. 9  and  FIG. 12 , respectively, wherein the detent element and detent engagement element are located along the barrel portion and approximately adjacent to the contactor portion.  FIG. 14  and  FIG. 17 , for example, depict an alternate location for the detent element and detent engagement element, wherein these elements are located along the barrel portion approximately adjacent proximal end  28 . 
   The tubular sleeve member  40  is further adapted to being deformable to hermetically seal the core  36  as depicted, for example, in  FIG. 5 ,  FIG. 10  and  FIG. 13 . To facilitate such deformation, the sleeve member can be made of one of several materials which may be crimpable or heat-shrinkable. Moreover, the sleeve may be comprised of an electrically conductive metallic material. Tubular sleeve member materials comprise, for example, copper or a heat-shrinkable organic or inorganic polymer, because they can generally be crimped or shrunk, respectively, using lightweight, portable tools. Additionally, as illustrated, for example, in  FIG. 11  through  FIG. 13 , the tubular member  30  may have a hole  54  generally radially thererthrough adjacent the closed end of tubular member  30 . The sleeve member may be made of a substantially transparent heat-shrinkable polymer, allowing for viewing through hole  54  even after the sleeve has been deformed to form the hermetic seal. As illustrated, for example, in  FIG. 10 , hole  54  is adapted to being inspectingly associated with a spot  35  on bare tip  34  when bare tip  34  is substantially fully inserted into the tubular member  30 . End  45  of bare tip  34  is at about the closed end of tubular member  30  when spot  35  becomes visible through hole  54 . 
   Some embodiments of the present invention may also include a shoulder member  25  which is located axially along contact member  20  medial of the proximal and distal ends. As shown, for example, in  FIG. 6 , the shoulder member  25  may be positioned at the junction of the electrical contactor portion  22  and barrel portion  24 . Further, as depicted, for example, in  FIG. 15  and  FIG. 16 , the shoulder member  25  may form part of the detent engaging element  48 , where the shoulder member prevents or helps prevent the sleeve member  40  from sliding toward the distal end  26  beyond the shoulder member&#39;s location prior to deformation of the sleeve member to form the hermetic seal. Certain embodiments do not include a shoulder. See, for example,  FIG. 14 . 
   As depicted, for example, in  FIG. 18 , in some embodiments of the present invention the tubular member  30  may include a crimp cushioning region  52 , which is adapted to being crimpably deformed into electrical continuity with the bare tip  34  of the core of a wire. This crimp cushioning region provides cushioning for more brittle wire material such as aluminum during the crimping of the tubular member  30  into electrical continuity with a brittle core. The crimp cushioning region  52  may comprise a soft metal liner in tubular member  30 . The liner does not obscure the hole  54 . 
   With particular reference to  FIGS. 11 through 13 , and  16 , an embodiment is illustrated in which tubular sleeve member  47  is substantially transparent. This transparent member includes a detent element  49  in the form of a ridge element molded into the inner generally cylindrical surface of member  47 . This ridge element engages the detent engaging element on the contact member to hold the assembly in the proper configuration while the crimp sealing operation is being performed. The spot  35  on bare tip  34  is visible through hole  54  even after the assembly operation has been completed as indicated at  51 . This permits quick and reliable inspection of the completed assembly. 
   IN the embodiment of  FIGS. 14 and 17 , the detent elements are adjacent the proximal end of the contact member. Tubular sleeve member  53  includes nipple elements, of which  55  is typical, projecting radially inwardly from the inner circumference of tubular sleeve member  53 . Adjacent the proximal end of the contact member is a circumferential groove element  59 . Elements  55  and  59  together provide the detent and detent engaging elements to hold tubular sleeve member  53  in the proper configuration for crimp sealing. 
   Embodiments of contact assemblies according to the present invention are well suited for use with both aluminum and copper cored wire. This dual capability greatly simplifies inventory control and reduces the risk of errors on large installations, such as transport aircraft, where both copper and aluminum core wire are being installed. These contact assemblies are also useful in installations where other types of stranded or solid core wire are being installed. Accordingly, the present invention should not be construed as limited solely to any particular core composition or configuration. 
   It will be appreciated that embodiments of the present invention may be profitably employed in the context of a wide variety of insulated stranded and solid core wires, and in original, retrofit and maintenance operations. Aluminum cores typically require hermetic sealing. Copper and other metal cores need to be protected from corrosion in some marine and other corrosive environments such as on ships, aircraft, and shore installations. Any material or combination of materials, compatible with the functions and operation of the present invention is contemplated as being within the scope of the present invention. Some manufacturing operations involve operations that are performed in corrosive environments. For maintenance and retrofit operations it is often impossible or impractical to remove the wiring harness and take it to a bench to work on. Original installations must sometimes be completed at the site of use where a bench is not available. 
   It will be appreciated that the required deforming operations may be accomplished by a variety of devices and structures other than manually operated deforming tools. Powered hand crimping tools, and powered bench mounted tools can be employed, if desired. 
   What have been described are embodiments in which modifications and changes may be made without departing from the spirit and scope of the accompanying claims. Many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described and shown.