Patent Description:
Sealing of wire bundles is typically required in applications where large numbers of wires pass through a wall that separates regions having different environmental conditions. An example of a known system used for this purpose is disclosed in <CIT>. For example, in automobiles, wires from various sensors, controllers and the like may pass from the engine compartment, through an opening in the firewall, to a computer located in the cabin. In the region where the wires pass through the opening, the wires may be surrounded by a sealing member. The sealing member is configured to completely encapsulate the wires and ideally fill in voids between the wires to prevent moisture from traveling along the wires into the cabin. The sealing member or members are also configured to provide a watertight fit with the opening in the firewall. The sealant also provides sound dampening, thus reducing the noise level in the passenger compartment.

Some sealing members are formed by surrounding each wire of the bundle or a group of wires of the bundle with a comb or a ring or a sleeve formed from a sealant composite material in the region to be sealed. The sealant composite material may include magnetic flakes. Next, a sleeve with or without the sealant composite material may be placed around the entire bundle in the region to be sealed. Finally, the assembly is subjected to a strong magnetic field that induces local heating in the magnetic material, which in turn causes the sealant to soften and flow and thereby seal the bundle of wires.

However, the method described above has several disadvantages. For example, there is a possibility of overheating due to electromagnetic coupling between the wires and the magnetic field which may occur when the wires are twisted. This may result in wire insulation layer damage. The magnetic flakes of specific composition and configuration may need to be oriented in a particular way when inserted into the sealant, which can increase production time and cost. The requirement that each wire or group of wires (typically two wires) be surrounded by a comb increases the bulk of the sealing member.

Other problems with existing sealing members will become apparent in view of the disclosure below.

In a first aspect, an integrated sealing assembly for sealing a bundle of wires according to claim <NUM> is provided. The integrated sealing assembly includes a first sheet formed of a sealant material, a second sheet disposed above the first sheet, and a third sheet disposed above the second sheet. The second sheet includes a thermally conductive material. When the bundle of wires is overlaid on the assembly in a first direction, and the assembly is wrapped in a second direction that is generally perpendicular to the first direction to thereby surround the wires, the second sheet facilitates thermal energy distribution of applied heat throughout the assembly to thereby soften the sealant material and thereby lower viscosity of the sealant material to a point at which the sealant material flows and fills voids between the bundle of wires. A cover may be provided to maintain the sealant material between the wires.

An example of an integrated sealing assembly for sealing a bundle of wires includes a lower portion that defines a generally planar shape, a plurality of vertical members extending from the lower portion having a space therebetween for placement of one or more wires in a first direction, and a thermally conductive material embedded within the lower portion. The integrated sealing assembly is formed from a sealant material. When one or more wires are arranged within the space between the plurality of vertical members in the first direction and the integrated sealing assembly is wrapped in a second direction that is generally perpendicular to the first direction to thereby surround the wires, the thermally conductive material of the integrated sealing assembly facilitates thermal energy distribution of applied heat throughout the assembly to thereby lower a viscosity of the sealant material to a point at which the sealant material of the integrated sealing assembly fills voids between the one or more wires.

A preferred embodiment of the first aspect of the invention provides an integrated sealing assembly for sealing a bundle of wires comprises: a first sheet formed of a sealant material; a second sheet disposed above the first sheet, the second sheet including a thermally conductive material; and a third sheet that can be disposed above the second sheet; characterized in that the third sheet is formed of the sealant material and defines a plurality of teeth on a top surface that define valleys there between for controlled placement of one or more wires of the bundles of wires, wherein the thermally conductive material extends from the second sheet into at least some portions of the plurality of teeth, wherein when the bundle of wires is overlaid in a first direction on the assembly, the assembly is wrapped in a second direction that is generally perpendicular to the first direction to thereby surround the wires, the second sheet facilitates the thermal energy distribution of applied heat throughout the assembly to thereby lower a viscosity of the sealant material to a point at which the sealant material fills voids between the bundle of wires.

A second aspect of the invention provides a method for sealing a bundle of wires according to claim <NUM>. The method comprises providing a sealing assembly comprising a first sheet formed of a sealant material, a second sheet disposed above the first sheet, and a third sheet disposed above the second sheet formed of the sealant material. The second sheet includes a thermally conductive material. The bundle of wires is overlaid on the third sheet in a first direction. The sealing assembly and bundle of wires are wrapped together in a second direction that is generally perpendicular to the first direction. Heat is applied to the wrapped assembly. The second sheet facilitates thermal energy distribution of the applied heat throughout the assembly to thereby uniformly melt the sealant material and thereby fill voids between the wires.

In further embodiments of the invention the second sheet further comprises a second sealant material. Preferably the viscosity properties of the second sealant material are different to the viscosity properties of the first sealant material.

The first sealant material preferably has a viscosity less than <NUM> Pa·s above a temperature of about <NUM>, and a viscosity greater than <NUM> Pa·s at a temperature below about <NUM>. The first sealant material preferably includes a crosslinking agent to cause the sealant to undergo a change in viscosity characteristics when heated to a curing temperature such that the viscosity of the first sealant material is initially less than about <NUM> Pa s at the curing temperature and then changes to a viscosity of greater than about <NUM> Pa·s at the curing temperature after crosslinking has occurred.

The third sheet disposed above the second sheet defines a plurality of teeth on a top surface that define valleys therebetween for controlled placement of one or more wires of the bundles of wires. The thermally conductive material suitably extends from the second sheet into at least some portions of the plurality of teeth. Preferably the first and third sheets further comprise a third sealant along edges of the first and third sheets which extends in a direction that is parallel with the second direction in which the assembly is wrapped. Suitably the viscosity of the third sealant is greater than a viscosity of the first sealant. This inhibits the first sealant from escaping from end sections of the wrapped assembly while heat is applied to the assembly.

In one embodiment the cover corresponds to a heat-shrinkable material.

In a preferred embodiment of the second aspect of the invention there is provided a method for sealing a bundle of wires, the method comprising the steps of providing a sealing assembly according to claim <NUM> and overlaying the bundle of wires on the first sheet in a first direction; wrapping the sealing assembly and bundle of wires together in a second direction that is generally perpendicular to the first direction; and applying heat to the wrapped assembly, wherein the second sheet facilitates uniform thermal energy distribution of applied heat throughout the assembly to thereby uniformly melt the sealant material and thereby fill voids between the wires. Preferably the second sheet further comprises a second sealant material having a viscosity different to the viscosity properties of the first sealant material. Preferably the first sealant material has a viscosity less than <NUM> Pa·s above a temperature of about <NUM>, and a viscosity greater than <NUM> Pa·s at a temperature below about <NUM>. The sealing assembly suitably includes a third sheet disposed above the second sheet formed of the sealant material, which includes a plurality of teeth on a top surface that define valleys therebetween for controlled placement of one or more wires of the bundles of wires. The thermally conductive material preferably extends from the second sheet into at least some portions of the plurality of teeth. The sealing assembly suitably includes a cover, which is placed around the wrapped sealing assembly and the bundle of wires to inhibit melt sealant from spilling. Preferably the cover corresponds to a heat-shrinkable material.

The first and third sheets further comprise a third sealant along the edges of the first and third sheets that extends in a direction parallel to the longitudinal direction in which the assembly is spirally rolled. The viscosity of the third sealant is suitably greater than the viscosity of the first sealant which inhibit the first sealant from escaping from end sections of the wrapped assembly while heat is applied to the assembly during the process of sealing the bundle of wires.

The method of sealing the bundle of wires suitably further comprises compressing and twisting the sealing assembly to enhance distribution of the sealant material between the voids between the wires. Preferably one or more of the first, second, and third sheets includes an infrared absorbing material so that heat can be applied to the spirally rolled assembly using infrared energy. Alternatively one or more of the first and second sheets includes a ferromagnetic material, and heat can be applied to the wrapped assembly using inductive energy.

<FIG> illustrates a cross-section of an exemplary sealing assembly <NUM> for sealing a bundle of wires. The sealing assembly <NUM> includes top and bottom layers 105a, 105b or sheets formed from a sealant material. The middle layer <NUM> or sheet includes a thermally conductive material and a sealant material, which may be the same or different than the sealant material used for forming the top and bottom layers 105a, 105b. The thermally conductive material helps to promote more uniform and faster distribution of heat through the sealing assembly <NUM>.

The top, middle and bottom layers 105a, <NUM>, and 105b may be formed from one of several sealant materials described below. In an exemplary implementation, the thickness of the top and bottom layers 105a,105b may be between about <NUM>-<NUM>. The thickness of the two layers 105a,105b may be the same or different.

The middle layer <NUM> includes a thermally conductive material embedded within the sealant material from which the middle layer is formed. The middle layer <NUM> may have a thickness of between about <NUM>-<NUM>, <NUM>-<NUM>, <NUM><NUM>-<NUM>, or a different thickness. The thermally conductive structure may correspond, for example, to a metal mesh or metal wool and may have a thickness of between about <NUM>-<NUM> or a different thickness. Other conductive structures may be utilized.

The thermally conductive structure may correspond to a continuous structure that extends in the wrapping/longitudinal direction (<NUM>, <FIG>) of the sealing assembly <NUM>. In this regard, the thermally conductive structure may have a thermal conductivity range of 50W/mK or higher. In other embodiments, the thermally conductive structure may correspond to conductive material fragments that are sufficiently close to another to promote more uniform heat distribution.

The wire from which the thermally conductive structure is formed may have a diameter of between about <NUM> and <NUM>, and the mesh opening size may be between about <NUM>-<NUM>. The wire may be formed from copper, aluminum, brass, bronze, steel-based materials, and/or alloys with high thermal conductivity. Other materials having similar thermal conductive characteristics may be utilized. For example, metal foils, formed metal foils, or perforated metal foils may be utilized as the thermally conductive structure. The thermally conductive structure may be coated with a thin electrically insulating material layer, which can provide electrical insulation while being thin enough not to affect the thermal conductivity or the ability to facilitate heat transfer during assembly.

Sealant materials that may be utilized for forming the top, middle and bottom layers 105a, <NUM>, and 105b generally correspond, to a hot melt thermoplastic sealant such as polyolefin based sealant (e.g., the base polymer is polyethylene (PE), metallocene-formed PE, maleic anhydride functionalized PE, or glycidyl methacrylate functionalized PE), polyolefin copolymer based sealant (e.g., the base polymer is ethylene-vinyl acetate copolymer (EVA)), a polyamide-based sealant, a thermoplastic elastomer (TPE) based sealant, a polyolefin and polyamide (PA) mixture based sealant, a polyolefin and polyolefin copolymer mixture based sealant (e.g., PE:EVA in weight ratios <NUM>:<NUM>, <NUM>: <NUM>, <NUM>:<NUM>, or <NUM>:<NUM>), a polyolefin copolymer and polyamide mixture based sealant (e.g., EVA:PA in weight ratios <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, or <NUM>:<NUM>). A different sealant or sealant mixture with similar characteristics may be utilized.

For example, a first sealant material for forming the top, middle and bottom layers 105a, <NUM>, and 105b may be characterized by the following parameters:.

A second sealant material for forming the top, middle and bottom layers 105a, <NUM>, and 105b may be characterized by the following parameters:.

The viscosity of the first and second sealant materials as well as the viscosity of the sealant materials described below was measured using a rotation rheometer. In this method, a small disk of sealant material (e.g., <NUM>-<NUM> thick, <NUM> diameter disk) is placed between plates of the rotation rheometer and sheared (oscillatory mode) by means of a rotational motion frequency of <NUM> rad/sec. The temperature of the sealant material is gradually increased from <NUM> to <NUM> at a rate of <NUM>/min and the complex viscosity is measured as a function of temperature. The softening temperature referred to herein was the Ring and Ball softening temperature as measured according to ASTM E28.

A third sealant material for forming the top, middle and bottom layers 105a, <NUM>, and 105b may include a crosslinking agent to cause the sealant to undergo a change in viscosity characteristics when heated to a curing temperature. When subjected to an elevated temperature (e.g., at or above the softening temperature) for a time sufficient to allow the polymers in the sealant crosslink (e.g., one to ten minutes) the viscosity of the sealant increases. This results in a sealing assembly that can withstand higher temperatures, such as those temperatures that may be present in an automotive engine compartment.

The third sealant material may include low molecular weight polymers (e.g., wax); a crosslinking agent (e.g., a peroxide, silanes), crosslinking promoting additives (co-agents, e.g., triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTMA)), a polyolefin/polyamide/polyolefin copolymer (e.g., EVA) and other fillers or additives, such as carbon black, antioxidants, stabilizers, tackifiers, etc. The sealant may contain <NUM>-<NUM> weight % (wt%) base polymer, <NUM>-<NUM> wt% low molecular weight polymer, <NUM>-<NUM> wt% peroxide, <NUM>-<NUM> wt% co-agent, and <NUM>-<NUM> wt% of other additives.

The resultant sealant may be characterized by the following parameters:.

In some implementations a different sealant may be utilized for forming the middle layer <NUM>. For example, a fourth sealant, which may be utilized to form the middle layer <NUM>, may be characterized by the following parameters:.

Various materials may be added to any the sealants described above to improve the sealing characteristics. For example, the sealants may include filler materials to improve thermal conductivity without compromising the viscosity characteristics listed above. The filler materials may correspond to carbon, copper, nickel, aluminum, stainless steel, copper containing alloys, a copper-tin mixture, boron nitride, aluminum nitride, aluminum oxide, silicon carbide, beryllium oxide, silicon nitride, magnesium oxide, and/or other fillers.

In some implementations, the sealants may include stabilizer materials to improve longtime temperature aging characteristics. For example, the sealant materials may have <NUM>-<NUM> wt% antioxidants (e.g., sterically hindered phenolic antioxidants) and/or secondary antioxidants (e.g., thioesters, lauryl/stearyl thiopropionate). Tackifiers may be added at <NUM>-<NUM> wt% to improve adhesion.

In some implementations, physical or chemical foaming agents may be added to the sealants to improve the flow behavior and to reduce the sealant material usage.

<FIG> illustrates a cross-section of a second exemplary sealing assembly <NUM> for sealing a bundle of wires. The second exemplary sealing assembly <NUM> corresponds to the first sealing assembly embodiment with the addition of teeth <NUM> or ridges formed on the top layer 105a. The teeth <NUM> may be formed with the sealant used for forming the top layer 105a.

In some implementations, the conductive material in the middle layer <NUM> may extend through the top layer 105a and into the teeth <NUM>. The teeth <NUM> help promote sealing between the wires by melting and flowing in between wires. In addition, the teeth <NUM> serve as guides that facilitate more uniform placement of wires on top of the assembly.

The teeth <NUM> may run perpendicular to the wrapping/longitudinal direction <NUM> of the sealing assembly <NUM> as illustrated in <FIG> illustrate different exemplary patterns in which the teeth <NUM> may be arranged on the top layer 105a. As illustrated in <FIG>, the teeth <NUM> may extend from one edge of the assembly <NUM> to the opposite edge. As illustrated in <FIG>, some teeth may be shorter than other teeth. Other arrangements of the teeth <NUM> may be utilized as circumstances require.

In an exemplary implementation, the teeth <NUM> may have a width, W1, of between about <NUM>-<NUM> and a height, H, of between about <NUM>-<NUM>. The teeth <NUM> may be spaced apart from one another by a distance, S, of between about <NUM>-<NUM>. The shape of the teeth may vary. For example, as illustrated in <FIG>, the teeth may have a triangular shape in cross-section. However, the teeth may have a rectangular cross-section or a different cross-section.

<FIG> illustrates a cross-section of a third exemplary sealing assembly <NUM> for sealing a bundle of wires. The third exemplary sealing assembly <NUM> corresponds to the second sealing assembly embodiment with the addition of a heat shrinkable material layer <NUM>. In an third exemplary sealing assembly <NUM>, the thickness of the heat-shrinkable material layer <NUM> may be between about <NUM>-<NUM>.

The heat-shrinkable material layer <NUM> may be formed from materials such as crosslinked polyolefin (e.g. polyethylene copolymer) or fluoropolymer (e.g.ethylene-tetrafluoroethylene copolymer (ETFE) or non-crosslinked materials (e.g., polyethylene terephthalate (PET)) with or without sealants (e.g. sealants in which the polymer base material is polyamide or a polyethylene copolymer such as ethylene-vinyl acetate copolymer (EVA)). Commercial heal-shrink tapes may be utilized. The material from which the heat-shrinkable material layer <NUM> is formed may have a shrinkage of <NUM>-<NUM>% between <NUM>-<NUM>. The layer <NUM> shown in <FIG> and <FIG> may be positioned adjacent to layer 105b (in <FIG>) or adjacent to layer 605b (in <FIG>).

<FIG> help illustrate an exemplary methodology by which the third exemplary sealing assembly <NUM> may be utilized to seal a bundle of wires <NUM>. It should be understood that the methodology may be applied to the other assemblies.

As illustrated in <FIG>, in one implementation, the assembly <NUM> may be provided in a generally flat form. Wires <NUM> may then be placed upon the assembly <NUM>. At this stage, the teeth <NUM> may act as guides to facilitate even distribution of the wires <NUM> over the top layer 105a of the assembly <NUM>. For example, the number of wires <NUM> placed within the valleys defined between the teeth <NUM> may be selected so that the wires do not spill over into adjacent valleys. In addition, the teeth <NUM> help ensure that the wires cross over the assembly in a direction that is transverse to the direction in which the assembly will be wrapped or rolled.

As illustrated in <FIG>, the assembly <NUM> and wires <NUM> may be rolled or wrapped in a longitudinal direction <NUM> within the assembly <NUM> so that the assembly <NUM> covers all the wires. For example, the sealing assembly <NUM> and wires <NUM> may be spirally rolled in a spiral direction <NUM> so that the assembly <NUM> covers all the wires <NUM>. Heat may then be applied to the spirally rolled sealing assembly and wires <NUM>. For example, the spirally rolled assembly and wires <NUM> may be heated in an oven, via a heat gun, and/or via some other heating system to a temperature of between about <NUM>-<NUM> (as measured inside the assembly) for between about <NUM>-<NUM> minutes to obtain sealing. In this regard, the thermally conductive material within the middle layer <NUM> helps to promote more uniform and faster distribution of heat energy throughout the spirally rolled assembly sealing assembly and wires <NUM> by conducting heat energy from the outer area of the spirally rolled assembly and wires <NUM> to the interior of the spirally rolled assembly and wires <NUM>.

As illustrated in <FIG>, the top and bottom layers 105a,105b of sealant material may melt together and fill voids between the wires <NUM> thereby sealing the wires <NUM>. When included in the embodiment, the heat-shrinkable material layer <NUM> forces the spirally rolled assembly and wires <NUM> to shrink in a radial direction. This in turn helps to squeeze the melted, or in some embodiments, softened sealant material into the voids.

In an alternative implementation, the assembly <NUM> may be folded into the shape illustrated in <FIG> or the shape illustrated in <FIG>. The wires <NUM> may then be placed within folds <NUM> of the folded assembly. The folded assembly may then be compressed so that the assembly is in tight contact with the wires and then heated to seal the bundle of wires.

It should be understood that the assembly <NUM> may be folded into different shapes. In addition, the illustrated shape may be obtained by methods other than folding. For example, the assembly <NUM> may be extruded from a die or be molded or overmolded from a mold, etc., and form a variety of shapes.

<FIG> provides an example of a sealing assembly <NUM> that may be utilized to seal a bundle of wires <NUM>. The sealing assembly <NUM> may be formed using any of the sealants described herein via a molding technique such as extrusion from a die, molded or overmolded from a mold, etc..

As illustrated, the sealing assembly <NUM> may define a comb-like structure. For example, the sealing assembly <NUM> may include a lower portion <NUM> and a plurality of vertical members <NUM> or teeth extending from the lower portion <NUM> between which wires <NUM> may be inserted. The lower portion <NUM> may have a generally planar shape with a width, W1, of about <NUM>-<NUM>. A depth of the lower portion <NUM> (i.e., the distance into the drawing and not shown) may be about <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> The vertical members <NUM> may extend from the lower portion <NUM> to form a <NUM>° angle with the lower portion <NUM>, or may be at any other convenient angle for insertion of wires <NUM>.

The vertical members <NUM> may have a width, W2, of about <NUM>-<NUM>, a height, H, of about <NUM>-<NUM>, and may be spaced apart by a distance, L, of about <NUM>-<NUM>. The vertical members <NUM> may be spaced evenly between first and second ends 370a,370b of the lower portion <NUM> or may be spaced differently.

In one implementation, a conductive material <NUM> may be embedded in the lower portion <NUM> of the sealing assembly <NUM>. While not illustrated, in other implementations, the conductive material may be embedded in the vertical members <NUM> as well.

The conductive material <NUM> may correspond to any of the conductive materials described herein. The conductive material <NUM> may extend continuously between, for example, the first and second ends 370a,370b of the lower portion <NUM>, as illustrated, or discontinuously. For example, conductive material fragments that may or may not make direct contact with one another may be dispersed in the lower portion <NUM> or vertical members <NUM>. In this regard, a distance between the conductive material fragments may be as much as <NUM>.

As described above, the conductive material <NUM> facilitates improved heat distribution throughout the assembly <NUM>. This in turn facilitates improved softening or melting of the sealant from which the assembly <NUM> is formed.

Similar to the other implementations, the wires <NUM> may be inserted between the vertical members <NUM>. The assembly <NUM> and wires <NUM> may then be wrapped or rolled and then inserted within, for example, a heat shrinkable tube. Heat may then be applied to cause the sealant to soften or melt and the heat shrinkable tube to compress the sealant so that the sealant fills the voids between the wires <NUM>.

In some implementations, an article, such as a heat-shrinkable article, an expanded rubber cover, a grommet or a different cover may be placed over the sealing assembly and wires prior to or during heating to apply constricting force to the sealing assembly and wires to promote flow of the sealant during heating. For example, <FIG> illustrates a heat-shrinkable article <NUM> placed around the spirally rolled sealing assembly and wires <NUM> illustrated in <FIG>. <FIG> illustrates shrinkage of the heat-shrinkable article <NUM> around the spirally rolled sealing assembly and wires <NUM>. The heat-shrinkable article <NUM> applies additional constricting force to the spirally rolled sealing assembly and wires <NUM> to help ensure that the sealant material flows into the voids.

Similarly, <FIG> illustrates the sealing assembly <NUM> when folded into the configuration illustrated in <FIG>, with a heat-shrinkable article <NUM> placed over the sealing assembly <NUM>, and wires <NUM> inserted therein prior to heating. <FIG> illustrates shrinkage of the heat-shrinkable article <NUM> around the assembly <NUM> and wires <NUM>.

Heat recoverable (especially heat shrinkable) articles, for example tubes, "boots", "udders", sleeves, wrap-around sheets, tapes and moldings. The heat-shrinkable article <NUM> may correspond to a commercial single or double layer heat-shrinkable sleeve tube such as RNF-<NUM> or ATUM tubing sold by TE Connectivity Corporation. The heat-shrinkable article <NUM> may include sealants such as a polyamide sealant, EVA sealant, etc. Carbon, copper-tin, and/or other materials may be included to improve the thermal conductivity of the heat-shrinkable article <NUM>,.

The wall thickness of the heat-shrinkable article <NUM> (or in the case of a heat-shrinkable tape, a thickness of the heat-shrinkable tape) before shrinking may be between about <NUM>-<NUM>. The heat-shrinkable article <NUM> may have a shrink ratio of <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, or a different shrink ratio. The shrink temperature may be between about <NUM>-<NUM>.

<FIG> illustrates the assembly <NUM> or the assembly <NUM> with the heat-shrinkable sleeve <NUM> in final form. As shown, the wires <NUM> may extend from opposite ends of the assembly <NUM>/<NUM>. The sealed assembly <NUM>/<NUM> may then be utilized for its intended application. For example, in an automotive environment, the sealed assembly <NUM>/<NUM> facilitates running wires from the engine compartment through the firewall and into the cabin of the vehicle. The sealed assembly <NUM>/<NUM> may be snuggly fitted into an opening in the firewall, thereby preventing the ingress of water into the cabin of the vehicle from the engine compartment. For example, if a grommet is not already being used as a cover for the assembly, the sealed assembly <NUM>/<NUM> may be inserted into a grommet and the grommet and sealed assembly <NUM>/<NUM> may be positioned within the opening.

<FIG> illustrate fourth, fifth, and sixth sealing assembly embodiments <NUM>, <NUM>, and <NUM> that respectively include the features of the first, second, and third embodiments <NUM>, <NUM>, and <NUM> presented in <FIG>, respectively. The difference between the respective embodiments is that the sealant utilized for forming edge regions 612a,612b of the top and bottom layers 605a,605b of the fourth, fifth, and sixth sealing assembly embodiments <NUM>, <NUM>, and <NUM>, is different from a sealant material used for forming the middle region <NUM>. The sealant material or materials utilized in the middle region <NUM> may correspond to one or more of the first, second, third sealant materials for forming the top and bottom layers 105a, 105b of the first, second, and third embodiments <NUM>, <NUM>, and <NUM>, as described above. The sealant material for the edge regions 612a,612b may be selected to help slow or prevent, i.e. inhibit, the sealant in the middle region <NUM> from melting/pouring out of the assembly <NUM>, <NUM>, and <NUM> when heated.

The sealant of the edge regions 612a,612b may have a thickness between about <NUM>-<NUM> and be characterized by the following parameters:.

Like the sealants described earlier, the sealant at the edge regions 612a, 612b may include filler and stabilizer materials to improve thermal conductivity without compromising the viscosity characteristics listed above and to improve longtime temperature aging characteristics, respectively.

<FIG> illustrates the assembly embodiment <NUM> illustrated in <FIG> in final form. As described above, wires <NUM> may extend from opposite ends of the assembly <NUM>. The sealed assembly <NUM> may then be utilized for its intended application such as facilitating running wires from an engine compartment through a firewall and into the cabin of a vehicle, as described above.

As is the case for the first, second, and third assembly embodiments <NUM>, <NUM>, and <NUM>, a heat-shrinkable sleeve <NUM> or similar device that can apply a constricting force may be provided over the fourth, fifth, and sixth assembly embodiments <NUM>, <NUM>, and <NUM>, as illustrated in <FIG>. The heat-shrinkable sleeve <NUM> helps to further squeeze the melted or softened sealant material into the voids between the wires <NUM>.

<FIG> illustrates an exemplary compression operation that may be applied to any of the assemblies described above to improve the sealing characteristics of the assembly. Illustrated are the assembly of <FIG> and a pair of compression plates 900a,900b that may correspond to parts of a press, where the plates 900a,900b may be pressed against the assembly prior to or just after applying heat to the assembly <NUM>. The plates may define a generally cylindrical cavity <NUM> that defines the final/cured shape of the assembly. The amount of force is selected based on the viscosity of the sealant.

In some implementations, the plates 900a,900b may include end regions 910a,900b that extend passed the sealing assembly <NUM> and over a portion of the wires extending from the sealing assembly <NUM>. The diameter of the cylindrical cavity <NUM> at end regions <NUM>0a,900b may be reduced in comparison to the diameter of the center region <NUM> of the cylindrical cavity <NUM> to help prevent, i.e. inhibit, the sealant from spilling out through the ends of the assembly <NUM> during heating and compression.

One advantage of this implementation is that higher viscosity sealants may be utilized, such as sealants having a viscosity of more than <NUM> Pa·s at a temperature of great than <NUM>, which could effectively seal <NUM> wires or more with an applied pressure of about <NUM>kPa. Such sealants are less likely to spill out of the ends of the assembly. However, the sealants might not be capable of flowing between all the wires of the assembly without application of pressure. Thus, this implementation overcomes that problem.

In some implementations, heat may be conveyed to the assembly via the compression plates 900a,900b. This may facilitate more uniform heating of the assembly <NUM>.

While pressure is illustrated as being applied by a pair of plates 900a,900b, the pressure may be applied differently. For example, a different number of plates may be provided. A deflated bladder may be wrapped around the assembly, secured, and then inflated to compress the assembly <NUM>. The plates may be urged together via resilient members (i.e., compression springs) that connect the plates together. Other methods may be utilized.

As noted earlier, the middle layer <NUM> may include a thermally conductive material to promote distribution of heat energy throughout the assembly. In addition, or alternatively, in some implementations infrared (IR) heating or inductive heating may be utilized to heat the assembly.

Regarding IR heating, in some implementations, an IR absorbing material may be added to the sealant. For example, <NUM>-<NUM> wt % carbon black may be added to the any of the sealants described above. The IR absorbing material converts the IR energy to heat, which in turn lowers the viscosity of the surrounding sealant, causing the sealant to fill in the voids between the wires. As noted earlier, in some implementations a heat-shrinkable sleeve <NUM> may be placed over the assembly <NUM> prior to heating the assembly, as illustrated in the assembly <NUM> of <FIG>. To facilitate IR heating in this case, a transparent or semitransparent heat-shrinkable sleeve <NUM> may be utilized to allow the IR energy to passes through the heat-shrinkable sleeve <NUM> and to the IR absorbing material distributed throughout the assembly <NUM>.

Similarly, in cases where a press is utilized to compress the assembly, the compression plates 900a,900b may be formed from a transparent or semitransparent material to facilitate passage of IR energy.

To facilitate inductive heating, a ferromagnetic material may be added to the sealant. For example, nickel, nickel aluminum alloys, nickel chromium alloys, ferrites, and/or a different a ferromagnetic material may be added to any of the sealants described above. Generation of a relatively low power magnetic field (e.g., < 10W) may be sufficient to heat the sealant without damaging wire insulation.

While the method for manufacturing the sealing assembly has been described with reference to certain embodiments, it will be understood by those skilled in the art that the respective assemblies and or wires arranged therein may be twisted or turned while being heated further improving the distribution of the sealant material into the voids between the wires.

Claim 1:
An integrated sealing assembly (<NUM>, <NUM>) for sealing a bundle of wires comprises:
a first sheet (105b) formed of a sealant material;
a second sheet (<NUM>) disposed above the first sheet (105b), the second sheet (<NUM>) including a thermally conductive material; and
a third sheet (105a) that can be disposed above the second sheet (<NUM>),
characterized in that the third sheet (105a) is formed of the sealant material and defines a plurality of teeth (<NUM>) on a top surface that define valleys there between for controlled placement of one or more wires of the bundles of wires (<NUM>), wherein the thermally conductive material extends from the second sheet (<NUM>) into at least some portions of the plurality of teeth (<NUM>), wherein when the bundle of wires (<NUM>) is overlaid in a first direction on the assembly, the assembly is wrapped in a second direction that is generally perpendicular to the first direction to thereby surround the wires (<NUM>), the second sheet (<NUM>) facilitates the thermal energy distribution of applied heat throughout the assembly (<NUM>, <NUM>) to thereby lower a viscosity of the sealant material to a point at which the sealant material fills voids between the bundle of wires.