Patent Application
20180294629
The invention generally relates to a splicing device and a method for joining shielded wire cables.
Shielded wire cables typically include an insulated center conductor and a separate insulated shield conductor surrounding the center conductor insulation. The shield conductor may consist of a braided wire mesh, metal foil, or metalized film. The cables typically have a second insulation layer covering the shield conductor. Shielded wire cables have been long used for communications systems, such as in cable television transmission lines. Shielded wire cables are also finding use in high voltage applications in electric and hybrid electric vehicles. When shielded wire cables are spliced together, there is usually a need to electrically connect the shield conductors of the spliced cables as well as the center conductor, in order to maintain electrical continuity of the shield conductors. Interconnecting the shield conductors may be complicated because the shield conductors must be cut back from the spliced ends of the cable in order to join the center conductors. Interconnecting the shield conductors may be further complicated in a one-to-many splicing configuration, sometimes referred to as a Y-splice or H-splice.
A splicing device and a method for splicing shielded wire cables is described in U.S. Patent Publication No. 2015/0229115 published Aug. 13, 2015, herein incorporated by reference in it entirely. According to the splicing device 10 shown in
Therefore, an alternative splicing device and a method of splicing shielded cables that reduces the overall cable and splicing device length remains desired.
As of the time of filing this application, the invention described in this application and the invention described in U.S. Patent Publication No. 2015/0229115 are co-owned by Delphi Technologies, Inc.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
In accordance with one embodiment of this invention, a wire harness assembly is provided. The wire harness assembly includes a first shielded wire cable having a first exposed shield conductor and a first exposed core conductor, a second shielded wire cable having a second exposed shield conductor and a second exposed core conductor, and a third shielded wire cable having a third exposed shield conductor and a third exposed core conductor, and a generally planar bus bar formed of a conductive material. The first, second, and third exposed core conductors are welded to the bus bar, thereby electrically connecting the first, second, and third exposed core conductors. The wire harness assembly further includes a conductive sleeve enclosing a portion of the first, second, and third exposed shield conductors, an inner insulator enclosing the bus bar and disposed within the conductive sleeve, and an outer insulator enclosing the conductive sleeve.
The inner insulator may further include a first portion having a substantially rigid first wall defining a first locking feature and a substantially rigid second wall, wherein the first locking feature includes a first contact surface and a first locking surface intersecting the first contact surface and a second portion having a flexible arm defining a second locking feature. The second locking feature includes a second contact surface and a second locking surface intersecting the second contact surface. The first contact surface engages the second contact surface causing the flexible arm to bend as the first portion is joined to the second portion. The second wall limits bending of the flexible arm. The first locking feature and/or the second locking feature at least temporarily deforms when the bending of the flexible arm is limited by the second wall as the first portion is joined to the second portion. This deformation disengages the first contact surface from the second contact surface and thereby allows the first locking surface to engage with the second locking surface. The second wall may be defined by the second portion and may substantially parallel to the flexible arm. The first wall may be in contact with a substantially rigid third wall defined by the second portion. The first and second portions are preferably formed of an insulative polymeric material.
In accordance with another embodiment of this invention, method of splicing shielded wire cables together is provided. The method includes the steps of:
The inner insulator may further include a first portion having a substantially rigid first wall defining a first locking feature and a substantially rigid second wall and a second portion having a flexible arm defining a second locking feature, wherein the first locking feature includes a first contact surface and a first locking surface intersecting the first contact surface, wherein the second locking feature includes a second contact surface and a second locking surface intersecting the second contact surface, and wherein the method further comprises the steps of:
The second wall may be defined by the second portion and may substantially parallel to the flexible arm. The first wall may be in contact with a substantially rigid third wall defined by the second portion. The first and second portions are preferably formed of an insulative polymeric material.
In accordance with yet another embodiment of this invention, a housing is provided. The housing includes a first portion having a substantially rigid first wall defining a first locking feature and a substantially rigid second wall, wherein the first locking feature includes a first contact surface and a first locking surface intersecting the first contact surface and a second portion having a flexible arm defining a second locking feature. The second locking feature includes a second contact surface and a second locking surface intersecting the second contact surface. The first contact surface engages the second contact surface causing the flexible arm to bend as the first portion is joined to the second portion. The second wall limits bending of the flexible arm. The first locking feature and/or the second locking feature at least temporarily deforms when the bending of the flexible arm is limited by the second wall as the first portion is joined to the second portion. This deformation disengages the first contact surface from the second contact surface and thereby allows the first locking surface to engage with the second locking surface. The second wall may be defined by the second portion and may substantially parallel to the flexible arm. The first wall may be in contact with a substantially rigid third wall defined by the second portion. The first and second portions are preferably formed of an insulative polymeric material.
The second wall may be defined by the second portion and may substantially parallel to the flexible arm. The first wall may be in contact with a substantially rigid third wall defined by the second portion. The first and second portions are preferably formed of an insulative polymeric material.
Further features and advantages of the invention will appear more clearly on a reading of the following detailed description of the preferred embodiment of the invention, which is given by way of non-limiting example only and with reference to the accompanying drawings.
The present invention will now be described, by way of example with reference to the accompanying drawings, in which:
Described herein are devices and a methods for splicing two or more shielded wire cables together. The devices and methods may be used to splice shielded wire cables with a single center conductor, i.e. solid wire, or multiple center connectors, i.e. stranded wire. The devices and methods described herein may also be used to splice two or more shielded wire cables to form a H-splice or Y-splice. The devices and methods described herein may be used for splicing a variety of shielded wire cables types, for example high voltage shielded wire cables designed for electrical or hybrid electrical vehicles.
As illustrated in
An additional portion of each of the shield conductors may be removed or cut way to provide adequate voltage creepage distance to prevent a leakage current between the core conductors 102A, 104A, 106A and the shield conductors thereby exposing inner insulation jackets 102B, 104B, 106B of the shielded cables 102, 104, 106. The exposed shield conductors are folded back over the outer insulation jackets 102C, 104C, 106C and an inner ferrule (not shown) is placed between the inner insulation jackets 102B, 104B, 106B and the exposed shield conductors of each of the shielded wire cables 102, 104, 106 and an outer ferrule 108 is placed over each of the exposed shield conductors to provide a robust connection point for the shield conductors. The ferrules 108 may be a closed or barrel-type ferrule that is attached to the shield conductors by crimping or soldering prior to forming the connection or the ferrules 108 may be an open or clip-type ferrule that can be attached to the shield conductors by crimping after forming the connection. Materials and methods used to attach the conductive ferrules 108 to the shield conductors are well known to those skilled in the art.
The exposed portions of the core conductors 102A, 104A, 106A are attached to an electrically conductive bus bar 110 to electrically interconnect the core conductors 102A, 104A, 106A. The bus bar 110 has a generally rectangular shape and the core conductors 102A, 104A, 106A are attached to one of the major surfaces of the bus bar 110 by a welding process, preferably a sonic welding process although other welding processes such as resistance welding, soldering, brazing may be employed. The bus bar 110 may be formed of a copper or aluminum based alloy. When the cables 102, 104, 106 are cut in cut leads, the core conductors 102A, 104A, 106A are stacked or piggy-backed on one another when welded to the bus bar 110.
The assembly 100 includes an inner insulator , hereinafter referred to as an inner housing 112 formed of dielectric material. The dielectric material may be a polymer material, such as glass-filled polyamide (commonly known by the trade name NYLON) or polybutylene terephthalate (PBT). The inner housing 112 may be formed using an injection molding process or other plastic forming processes well known to those skilled in the art. The inner housing 112 may be formed by two identical halves, and upper inner housing 112A and a lower inner housing 112B that are designed to enclose the bus bar 110, the exposed core conductors 102A, 104A and the exposed inner insulation jackets 102B, 104B of the shielded cables 102, 104.
The inner housing 112 defines a lateral cavity 114 that is designed to accommodate the bus bar 110. The inner housing 112 also defines three longitudinal cavities 116A, 116B, 116C extending from the lateral cavity 114 that are designed to accommodate the shielded cables 102, 104, 106. As shown in
The assembly 100 further includes a sleeve 118 formed of conductive material in which the inner housing 112 is enclosed. The conductive material used to form the sleeve 118 is preferably a copper alloy, such as 425 brass and may be tin coated for corrosion resistance. The sleeve 118 defines contacts 120 that are designed to be in mechanical and electrical contact with the outer ferrules 108 attached to the shield conductors of the shielded wire cables 102, 104, 106. The contacts 120 protrude from the sleeve 118 and form an arcuate shape configured to exert a spring force on the outer ferrules 108.
As shown in
The assembly 100 further includes an outer insulator, hereinafter referred to as an outer housing 122 formed of a nonconductive material and defining a cavity 124 that is configured to enclose the sleeve 118. The assembly 100 also includes a pair of end caps 126 that are designed to sealably engage the shielded wire cables 102, 104, 106 and sealably engage the outer housing 122. The end caps 126 and outer housing 122 are designed to provide environmental protection by keeping contaminants such as dust, dirt, water, and other fluids away from to the exposed core conductors 102A, 104A, 106A, bus bar 110, and sleeve 118. The outer housing 122 and end caps 126 may be formed of a polymer material, such as NYLON or PBT. The end caps 126 may also include a sealing element formed of compliant material, such as silicone rubber, hereinafter referred to as seals 128.
Since the connections between the exposed core conductors 102A, 104A, 106A and the bus bar 110 are not serviceable, it is desirable to provide a tamper resistant locking feature to secure the upper inner housing 112A to the lower inner housing 112B so that they may not be separated once joined to reduce the chance of accidental contact with an energized core conductors 102A, 104A, 106A or bus bar 110.
As shown on the left side of
Accordingly, the first locking feature 132 of the lower inner housing 112B is configured to engage the corresponding the second locking feature 138 of the upper inner housing 112A. The first and second locking features 132, 138 may have corresponding first and second contact surfaces 132A, 138A and corresponding first and second locking surfaces 132B, 138B or may have different, but complimentary surfaces. In the illustrated example, the lower inner housing 112B has the first locking feature 132 that includes a lip or edge region 132C that comprises the first locking surface 132B that is intersected by the first contact surface 132A. Likewise, the upper inner housing 112A has a second locking feature 138 that includes a lip or edge region 138C that comprises the second locking surface 138 that is intersected by the second contact surface 138A. In this embodiment, the corresponding first and second locking surfaces 132B, 138B are configured for being coupled together when the upper inner housing 112A is joined to the lower inner housing 112B as shown in
As shown in
Again, without subscribing to any particular theory of operation, disengagement of the locking surfaces is inhibited because the first and second locking surfaces 132A, 138B remain engaged even when the flexible arm 136 is deflected against the second wall 134. The angled first and second locking surfaces 132B, 138B will pull the flexible arm 136 out of contact with the second wall 134, thereby maintaining the engagement of the first and second locking surfaces 132B, 138B and increasing a separating force Fs, that is in a direction opposite the joining force Fj, that is required to deform the edge regions 132C and/or 138C to allow disengagement of the first and second locking surfaces 132B, 138B to a level that is higher than the joining force Fj. Additionally, it is more difficult to apply the separating force Fs to the inner housing 112 than it is to apply the joining force Fj.
This tamper resistant locking feature may be adapted to other two-piece housings containing non-serviceable parts, for example housings for other electrical assemblies.
STEP 202, PROVIDE A FIRST, SECOND AND THIRD SHIELDED WIRE CABLE, includes providing a first shielded wire cable 102 having a first exposed shield conductor and a first exposed core conductor 102A, a second shielded wire cable 104 having a second exposed shield conductor and a second exposed core conductor 104A, and a third shielded wire cable 106 having a third exposed shield conductor and a third exposed core conductor 106A;
STEP 204, PROVIDE A FIRST, SECOND AND THIRD FERRULE, includes providing a first, second, and third ferrule;
STEP 206, ATTACH THE FERRULES TO SHIELD CONDUCTORS OF THE FIRST AND SECOND SHIELDED CABLES, includes attaching the first, second, and third ferrules 108 to the first, second, and third shield conductors respectively;
STEP 208, PROVIDE A BUS BAR, includes providing a generally planar bus bar 110 formed of a conductive material;
STEP 210, PROVIDE A CONDUCTIVE SLEEVE, includes providing a conductive sleeve 118;
STEP 212, PROVIDE AN INNER INSULATOR, includes providing an inner insulator formed of a thermoplastic material. The inner insulator 112 may include a upper portion 112A with a substantially rigid first wall 130 defining a first locking feature 132 and a substantially rigid second wall 134. The inner insulator 112 may also have a lower portion 112B with a flexible arm 136 defining a second locking feature 138. The first locking feature 132 includes a first contact surface 132A and a first locking surface 132B intersecting the first contact surface 132A. The second locking feature 138 includes a second contact surface 138A and a second locking surface 138 intersecting the second contact surface 138A;
STEP 214, WELD THE CORE CONDUCTORS OF THE FIRST AND SECOND SHIELDED CABLES TO THE BUS BAR, includes welding the first, second, and third exposed core conductors 102A, 104A, 106A to the bus bar 110, thereby electrically connecting the first, second, and third exposed core conductors 102A, 104A, 106A;
STEP 216, DISPOSE THE BUS BAR WITHIN THE INNER INSULATOR, includes disposing the bus bar 110 within the inner insulator 112;
STEP 218, APPLY A FORCE TO THE FIRST AND SECOND PORTIONS OF THE INNER INSULATOR, is an optional step that includes applying a joining force Fj to the upper and lower portions 112A, 112B of the inner insulator 112;
STEP 220, BEND THE FLEXIBLE ARM BY ENGAGING THE FIRST CONTACT SURFACE WITH THE SECOND CONTACT SURFACE, is an optional step that includes bending the flexible arm 136 by engaging the first contact surface 132A with the second contact surface 138A as the joining force F3 is applied to the first and second portions. The second wall 134 limits bending of the flexible arm 136;
STEP 222, DISENGAGE THE FIRST CONTACT SURFACE FROM THE SECOND CONTACT SURFACE, is an optional step that includes disengaging the first contact surface 132A from the second contact surface 138A as the joining force F3 is applied to the upper and lower portions 112A, 112B;
STEP 224, ENGAGE THE FIRST LOCKING SURFACE WITH THE SECOND LOCKING SURFACE, is an optional step that includes engaging the first locking surface 132B with the second locking surface 138;
STEP 226, DISPOSE THE INNER HOUSING WITHIN THE CONDUCTIVE SLEEVE, includes disposing the inner housing 112 and the first, second, and third exposed shield conductors within the sleeve 118;
STEP 228, ATTACH THE EXPOSED SHIELD CONDUCTORS TO THE CONDUCTIVE SLEEVE, includes attaching the exposed shield conductors to the sleeve 118. This may be accomplished by attaching the first, second, and third contacts 120 of the sleeve 118 to the first, second, and third ferrules 108 respectively, thereby electrically interconnecting the first, second, and third shield conductors through the sleeve 118;
STEP 230, PROVIDE AN OUTER HOUSING, includes providing an outer housing 122 formed of a nonconductive material; and
STEP 232, DISPOSE THE CONDUCTIVE SLEEVE WITHIN THE OUTER HOUSING, includes disposing the sleeve 118 within the outer housing 122.
Accordingly, a wire harness assembly 100 having a splicing device and a method 200 for joining together shielded wire cables 102, 104, 106 using such a device are provided. The splicing device provides the benefit of a shorter overall length than existing splicing devices for shielded cables because it eliminates the “fan out” length. The length reduction offers advantages of packaging a wire harness assembly made with such as splicing device, for example in a motor vehicle. The inventors have observed a reduction in the overall length of the splice device of 38% compared to existing splice devices. Using cut leads rather than center stripped cables provides benefits easier processing in the for stripping, ferrule and seal attaching. The assembly 100 also includes an inner housing 112 with tamper resistant locking features 132, 138 that inhibit access to the exposed core conductors 102A, 104A, 106A, once the inner housing is assembled.
While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow. Moreover, the use of the terms first, second, etc. does not denote any order of importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.
