Securing electrical conductors
An elongated electrical cable or flexible circuit board includes an electrically conductive path and an insulating body encompassing and electrically isolating the conductive path, the insulating body including an exposed surface having an array of fastener elements extending therefrom, the fastener elements arranged and constructed to engage mating fastener elements associated with a supporting surface to selectively secure the cable or flexible circuit board to the supporting surface. The fastener elements can be loop-engageable fasteners and/or loops. Such a cable or flexible circuit board is continuously formed by introducing an electrical insulating material including a thermoplastic resin into a gap formed adjacent a peripheral surface of a rotating mold roll, the mold roll defining an array of cavities therein, the insulating material being introduced under pressure and temperature conditions selected to cause the insulating material to at least partially fill the cavities to form fastener element stems integrally with and extending from one broad side of a strip of said insulation material; while introducing conductive wires and/or a conductive path formed on or within a substrate to the gap so as to cause the insulating material to envelop and electrically isolate the conductive path and/or to cause the conductive path to become an integral part of the strip of insulation material from which the fastener element stems extend.
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This application is a continuation of and claims priority under 35 U.S.C. §120 to PCT Application Serial No. PCT/US01/46045, filed Oct. 25, 2001, which claims priority to U.S. Provisional Application Ser. No. 60/293,743, filed May 25, 2001, U.S. Provisional Application Ser. No. 60/323,244, filed Sep. 19, 2001, and U.S. Provisional Application Ser. No. 60/243,353, filed Oct. 25, 2000, the entire contents of all four being hereby fully incorporated by reference.
TECHNICAL FIELDThis invention relates to electrical cables and circuits, and more particularly, to electrical cables and flexible circuits incorporating hook and/or loop fasteners.
BACKGROUNDThe use of electrical wires, cables and circuits throughout the world has become increasingly prevalent. With this growth has come the need to controllably direct and secure the routing of such conductors and processors to avoid electrical injury to people and to protect the electrical connections formed by such conductors from being inadvertently disconnected or worn during assembly and use.
For example, it is common in the automotive and other industries to position electrical cables, e.g., dome lamp cables, on the “non-show” surface (the surface not visible to vehicle passengers) of trim panels, e.g., headliners, to provide power for accessories, e.g., a dome lamp positioned within the headliner. Often it is desirable to secure such electrical cables in place to locate cable terminals for connection after trim panel installation and to prevent noise and cable fatigue associated with cable movement during the life of the assembly.
Ribbon cables, for example, are often employed within computers and other electronic devices where it is advantageous to secure the cables to, e.g., side panels, for ease of assembling other internal components, to avoid damage to the cables during assembly, and to reduce movement of the cables during use of the products to avoid wear and fatigue.
Electrical circuit boards and appliances often include a great number of electrical components interconnected for communication of electrical signals. Such interconnections typically require reliable connectors conducive to electrical conductivity that are installed and assembled by various means including, for example, soldering or plug and socket type engagement. These methods of installation and assembly often require precise alignment of mating pieces that are difficult to move and adjust when reconnection is required after initial assembly. It would be helpful if the fasteners provided secure yet releasable attachment and if they allowed for quick and efficient assembly without requiring precise alignment of the components to be interconnected.
Furthermore, it is common to secure electrical cables within the housings of computer hardware and peripheral equipment, within appliance housings and behind trim panels of automobiles by using various straps, adhesives, and other fastening materials and techniques. Often, electrical cables are secured in place to locate cable terminals for connection after trim panel installation and to prevent noise and cable fatigue associated with cable movement during the life of the assembly. Touch fasteners provide a convenient means of securing cables to side panels, for example, for ease of assembling other internal components, to avoid damage to the cables during assembly, and to reduce wear-inducing movement of the cables during use of the products.
SUMMARYThe invention features a cable or flexible circuit board with permanently attached fastener means extending along its length for securing the cable to a supporting surface.
According to one aspect of the invention, an elongated electrical cable includes at least two electrical conductors extending longitudinally along the cable and an insulating body encompassing and electrically isolating the conductors from one another, the insulating body including an exposed surface having an array of fastener elements extending therefrom, the fastener elements arranged and constructed to engage mating fastener elements associated with a supporting surface to selectively secure the cable to the supporting surface.
Variations of this aspect of the invention may include one or more of the following features. The fastener elements are shaped to engage exposed loop fibers associated with the supporting surface. The exposed surface of the insulating body includes a first broad surface of thermoplastic resin, the array of fastener elements being made up of raised projections of the thermoplastic resin. The exposed surface further includes a second broad surface of thermoplastic resin, a second array of fastener elements made up of raised projections of the thermoplastic resin extending from said second broad surface. The array of fastener elements is substantially coextensive with the first broad surface of the insulating body. The field of fastener elements forms a longitudinal band of fastener elements extending between lateral edge regions of the cable, the lateral edge regions being void of said fastener elements. The elongated electrical cable has an entire thickness, measured from distal ends of the fastener elements to an exposed broad surface of the insulating body opposite the fastener elements, of less than about 0.050 inch. The entire thickness is less than about 0.03 inch. The insulating body is a laminate, the laminate including a first and a second layer of thermoplastic resin and an adhesive layer disposed therebetween, the first layer defining a first broad surface of the exposed surface, the second layer defining a second broad surface of the exposed surface, the array of fastener elements being made up of raised projections of the thermoplastic resin of at least one of the first and the second broad surfaces. The insulating body is a unitary structure of thermoplastic resin, the unitary structure defining a first and a second broad surface of the exposed surface, the array of fastener elements being made up of raised projections of the thermoplastic resin of at least one of the first and the second broad surfaces. The insulating body includes a first and a second layer of thermoplastic resin with the conductors disposed therebetween, the first and second layers being permanently welded to one another in a manner to encompass and electrically isolate the conductors from one another, the array of fastener elements being made up of raised projections of the thermoplastic resin of an exposed surface of one of the first and second layers.
Yet additional features of this aspect of the invention may include one or more of the following. The fastener elements are exposed loop fibers. The insulating body includes a thermoplastic resin and the exposed loop fibers are part of a web of fibers, the web being attached to the insulating body by encapsulation of fibers of the web by the thermoplastic resin. The web of fibers is a nonwoven material. The elongated electrical cable defines a fixed cable length between opposite longitudinal ends, the cable further including an electrical connector electrically attached to at least one of the conductors and mechanically attached to the cable at one of the longitudinal ends.
In another aspect, the invention provides a releasably securable ribbon cable extending to define a longitudinal direction, the cable including a plurality of longitudinally extending electrical conductors, an insulating body encompassing and electrically isolating the plurality of conductors from one another, and a strip of loop-engageable fastener elements formed of thermoplastic resin, the strip extending longitudinally along the ribbon cable and being permanently attached to a surface of the insulating body such that the fastener elements are exposed for engagement with a loop material.
Another aspect of the invention provides a method of continuously forming an electrical cable, the method including:
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- introducing an electrical insulating material comprising a thermoplastic resin into a gap formed adjacent a peripheral surface of a rotating mold roll, the mold roll defining an array of cavities therein, the insulating material being introduced under pressure and temperature conditions selected to cause the insulating material to at least partially fill the cavities to form fastener element stems integrally with and extending from one broad side of a strip of said insulation material; while
- introducing at least two longitudinally continuous and spaced apart electrical conductors to the gap so as to cause the insulating material to envelop and electrically isolate the conductors and cause the conductors to become an integral part of the strip of insulation material from which the fastener element stems extend.
Variations of this aspect of the invention may include one or more of the following features. The cavities of the mold roll are shaped to mold distal heads on the fastener element stems, the distal heads being shaped to overhang the broad side of the strip of insulating material so as to be engageable with exposed loop fibers. Each of the stems defines a tip portion, the method further comprising deforming the tip portion of a plurality of the stems to form engaging heads overhanging the broad side of the strip of insulating material, the engaging heads being shaped to be engageable with exposed loop fibers. The gap is a nip defined between the rotating mold roll and a counter-rotating pressure roll. The gap is a nip defined between the rotating mold roll and a counter-rotating mold roll, each of the rotating mold roll and the counter-rotating mold roll defining an array of cavities therein, the insulating material being introduced under pressure and temperature conditions selected to cause the insulating material to at least partially fill the array of cavities of each of the rotating and the counter-rotating mold roll to form fastener element stems integrally with and extending from each of opposite broad sides of the strip of the insulation material. The insulating material includes a layer of thermoplastic resin and a film backing carrying the electrical conductors on a surface thereof, the layer of thermoplastic resin being introduced to the gap directly adjacent the rotating mold roll, the film backing carrying the electrical conductors being introduced to the gap under pressure and temperature conditions which cause the film backing to become permanently bonded to the thermoplastic resin to envelop and electrically isolate the conductors. The insulating material includes a first and a second film of thermoplastic resin, wherein the electrical conductors and the first and second films are introduced to the gap with the electrical conductors disposed between the first and the second film, said first film being introduced directly adjacent the rotating mold roll under temperature and pressure conditions that cause the first and second films to become permanently bonded to each other in a manner enveloping and electrically isolating the conductors. The method includes, downstream of the gap, longitudinally severing the electrical insulation material after solidification to form two electrical cables, each cable containing at least one conductor.
In another aspect, the invention provides a method of continuously forming an electrical cable, the method including:
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- introducing molten resin into a nip formed between a rotating mold roll and a counter-rotating pressure roll, the mold roll having a peripheral surface defining an array of blind molding cavities therein, under pressure and temperature conditions selected to cause the resin to fill the mold cavities and form an array of fastener element stems integrally molded with and extending from a broad strip of resin; while
- simultaneously introducing a preformed electrical ribbon-type cable to the nip adjacent the pressure roll, such that the broad strip of resin becomes permanently bonded to a broad side of the ribbon-type cable on a side opposite the fastener element stems.
In another aspect of the invention, a method of continuously forming an electrical cable includes:
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- providing a fastener tape of continuous length, the fastener tape comprising a base and an array of loop-engageable fastener elements, the base being of thermoplastic resin and defining a first and a second opposite broad surface, the array of loop engageable fastener elements comprising protrusions of the thermoplastic resin of the first surface;
- arranging a backing film of continuous length adjacent the fastener tape, the backing film defining a broad surface, the broad surface of the backing film being arranged to face the second broad surface of the fastener tape;
- disposing a plurality of spaced apart electrical conductors of continuous length between the second broad surface of the fastener tape and the broad surface of the backing film; and
- disposing a layer of electrically insulating adhesive between the second broad surface of the fastener tape and the broad surface of the backing film to cause the layer of adhesive to electrically isolate the plurality of conductors from one another while permanently bonding the fastener tape to the backing film to envelop the plurality of conductors therebetween.
In another aspect of the invention, a method of forming an electrical cable includes:
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- introducing a strip of molten electrical insulation material into a gap formed adjacent a peripheral surface of a rotating roll; while
- introducing a continuous strip of loop material to the gap along the surface of the roll, under conditions selected to cause the loop material to become at least partially embedded in the electrical insulation material to bond the loop material to the resin while leaving hook-engageable fiber portions exposed for engagement; and
- introducing at least two longitudinally continuous and spaced apart electrical conductors to the gap so as to cause the insulating material to envelop and electrically isolate the conductors in the gap to form a multi-conductor electrical cable having engageable loops extending from an outer surface thereof.
Cables (or wires) having integral fastening means can obtain numerous advantages. For example, continuous lengths of such fastener-bearing cable can be cut to any desired length and still retain its fastening properties. Additionally, the conductors can provide longitudinal reinforcement for the fastener base. The cable can be fashioned with a very low overall thickness, providing flexibility for easy routing, low bulkiness and associated material cost, and ease of cable concealment (e.g., for routing behind automotive interior panels). Furthermore, the invention can provide a fastenable cable without the structural redundancy of the fastener base and cable insulator.
In another aspect of the invention, a strip-form layer of electrical insulation having a pattern or circuit of conductive material disposed on one surface thereof (or fully insulated thereby, as in a flexible cable containing circuitry components) is fed through a hook-forming nip as described with reference to any of the above methods to form a hook-bearing layer integrally with the strip-form layer of electrical insulation.
In yet another aspect, the invention is a product formed by the method described immediately above.
In another aspect, the invention provides a flexible circuit board including a substrate having first and second, opposite broad surfaces, and a through-hole surface extending from the first to the second broad surface defining a passage between the first and second broad surfaces. The substrate further has an array of fastener elements extending from the first broad surface, the first broad surface and the array of fastener elements being formed integrally of a thermoplastic resin. A pattern of electrically conductive material is attached to the thermoplastic substrate, the pattern encompassing at least a portion of the through-hole surface.
This aspect of the invention may include one or more of the following features. The pattern of electrically conductive material is disposed only on the second broad surface and the at least a portion of the through-hole surface. The pattern of electrically conductive material is disposed only on the first broad surface and the at least a portion of the through-hole surface. The pattern of electrically conductive material encompasses at least a portion of the array of hook fastener elements. The pattern of electrically conductive material encompasses an entirety of the first or second broad surface.
In another aspect of the invention, an electrical cable includes a strip-form substrate having first and second, opposite broad surfaces and an array of fastener elements extending from the first broad surface. The first broad surface and the array of fastener elements are formed integrally of a thermoplastic resin, and a continuous strip of conductive material is attached to one of the first and second broad surfaces, the continuous strip being longitudinally coextensive with the strip-form substrate.
In another aspect of the invention, a method of forming an electrically conductive hook tape includes providing a substrate having first and second, opposite broad surfaces and an array of fastener elements extending from the first broad surface, the first broad surface and the array of fastener elements being formed integrally of a thermoplastic resin; applying a sensitizer to an exterior surface of the substrate; and applying a solution comprising a conductive material to the exterior surface where the sensitizer was applied, to produce a chemical reduction reaction between the conductive material and the sensitizer wherein the conductive material attaches to the exterior surface of the substrate.
Variations of this aspect of the invention may include one or more of the following features. A wetting agent is applied to areas of the substrate to be coated with the conductive material prior to application of the sensitizer. The sensitizer includes an anodic material that is disposed on the external surface of the substrate and the conductive material includes a cathodic material relative to the anodic material. The sensitizer comprises tin and the conductive material comprises silver. The solution further comprises an activator. The activator solution further comprises a reducer. The conductive material is applied to the first broad surface of the thermoplastic substrate. The conductive material coats at least a portion of the array of fastener elements. The method further includes a step of masking selected regions of the surface of the substrate prior to the step of applying sensitizer, thereby preventing attachment of the conductive material in the selected regions. The substrate further includes a through-hole surface extending between the first and second broad surfaces to define a passage. The conductive material is attached to at least a portion of the through-hole surface.
Another aspect of the invention provides a method of forming a flexible circuit board with integral hook fastener elements, the method including introducing an elongated flexible circuit including a substrate and at least one electrically conductive path to a gap adjacent a peripheral surface of a mold roll, the mold roll having hook fastener element stem forming cavities extending inwardly from the peripheral surface, while simultaneously, introducing a thermoplastic resin into the gap directly adjacent the peripheral surface under temperature and pressure conditions causing the thermoplastic resin to at least partially fill the stem forming cavities and to permanently bond to the substrate. Finally, the method includes stripping the permanently joined thermoplastic resin and substrate from the mold roll to expose the fastener element stems.
Variations of this aspect of the invention can include one or more of the following additional features. The conductive path is electrically insulated within the substrate prior to being introduced to the gap. A portion of the conductive path is exposed within the substrate for making an electrical connection with the conductive path. The portion of the conductive path is exposed prior to entering the gap. The portion of the conductive path is exposed by partial removal of the substrate after stripping the thermoplastic resin from the mold roll. The conductive path is disposed on an exterior surface of the substrate prior to being introduced to the gap, the thermoplastic resin being of an electrically insulating material, the conductive path being enveloped by the thermoplastic resin and the substrate. The conductive path is comprised of continuous strips of conductive material. The conductive path is comprised of discontinuous strips of conductive material that are electrically joined by electrical components.
In another aspect, the invention provides a securable flexible circuit including a carrier substrate of thermoplastic resin having a first broad surface and a second broad surface, the first broad surface being exposed and having an array of hook fastener elements protruding therefrom, the hook fastener elements formed as raised projections of the thermoplastic resin of the first broad surface, and an electrically conductive path disposed on said second broad surface.
Variations of this aspect of the invention can include one or more of the following features. The securable flexible circuit further includes a backing substrate having a first broad surface and a second broad surface, the backing substrate laminated to said carrier substrate with said electrically conductive path disposed between the second broad surface of the backing substrate and the second broad surface of the carrier substrate.
The backing substrate includes an array of hook fastener elements protruding from the first broad surface thereof. The backing substrate defines through-holes extending from said backing strip first broad surface to said backing strip second broad surface, the through-holes exposing portions of the conductive path. The securable flexible circuit further includes a layer of adhesive disposed between the backing substrate and the carrier substrate for lamination. The through-holes extend through the layer of adhesive.
Electrically conductive hook fastener substrates of the present invention provide for effective transmission of electrical signals on a flexible medium that can be reliably and releasably secured to a surface having complementary fastening material. In the assembly of products that include electronic components, such hook fastener substrates can be used, for example, as electrical cables. Such cables offer the advantage of being readily secureable to walls or other surfaces having complementary fastener materials. This allows the cables to be routed and secured in a manner that avoids interference with subsequent assembly operations and also eliminates subsequent wear-causing movement of the installed cables that may occur during use of the assembled product.
Such flexible conductive hook fastener substrates can be efficiently and continuously formed with integral hook fastener elements according to certain methods and apparatus of the invention. These techniques allow for electrical conductivity along the substrate in a patterned arrangement, on one or more surface, and/or on the hook fastener members themselves, as desired. Furthermore, the resulting conductive hook fastener substrates provide a surface on which other electrical components can be attached to process, relay, or modify electrical signals carried along the substrate.
The conductive coating of the fastener product of the present invention may be applied as an advantageously thin layer. In certain embodiments, the conductive layer is of a thickness less than 0.0015 inches (0.038 mm), while in other embodiments the conductive layer is less than 0.0010 inches (0.025 mm). By applying a thinner conductive layer, less weight is added in making the fastener product conductive and less conductive material is expended.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION Referring to
Electrical cables of the invention and their securement to a panel, e.g., headliners 10, 10′, will now be described. As illustrated in
Preferably, the non-woven loop material 44 is very thin, such as less than about 0.040 inch thick (more preferably, less than about 0.020 inch thick), with web fibers held in a transversely stretched condition and freestanding loop structures extending from its exposed surface. As discussed in the above-referenced patent application, the loop structures extend from associated knots in the stretched web, which may be stabilized by liquid binder wicked into the knots and cured. Between knots, the thin fiber mat is not very dense and is sheer enough to permit images to be readily seen through it. Overall, the loop material has a basis weight (in its preformed state, including any pre-applied binder) of less than about 4 ounces per square yard (136 grams per square meter), preferably less than about 2 ounces per square yard (68 grams per square meter). Other details of this loop material may be found in the above-referenced application. For applications in which the loop material is partially penetrated by resin of the substrate as the substrate is formed (as discussed below), the needled loop material is preferably only stretched in a transverse direction only about 22 percent to leave a fair amount of loft and avoid total penetration.
Some lightweight knits are also suitable loop materials for certain applications. Examples of such knits are Product 19902 from Guilford Knits in Greenville, S.C., which is of polyester fibers and has a basis weight of only about 1.6 ounces per square yard. For a heavier knit, Guilford's Product 20229, a nylon knit of about 3.3 ounces per square yard is suitable. Lightweight knit products are also available from TYBOR in Spain, and MIZARD in Italy.
In some instances, loop material 44 is partially encapsulated directly in resin of plastic base strip 40 as the substrate is formed in a continuous molding process (described below). In other cases, it is bonded to the formed substrate, either by ultrasonic bonding, welding, or adhesives.
The pattern of variable bonding shown in
For higher production rates, two or more electrical cables may be simultaneously produced on a single mold roll, and later split and spooled. Referring again to
Applying even pressure across nip 102 may lead to excessive resin penetration, or “flooding” of the loop material 144, which may reduce loop loft and have an adverse effect on fastener performance. In one embodiment, to avoid excessive resin penetration, mold roll 104 has staking rings 130 (
To form a row of heavily bonded points separated by regions of lower resin penetration, some staking rings 130 have a contoured outer edge as shown in
In another embodiment, also illustrated in
In an alternative method and apparatus illustrated in
The method and apparatus illustrated in
The methods and apparatus of
As illustrated in
Any of the methods and apparatus described above with, e.g., reference to
Conductor product 410 along with plastic resin 140 is fed through a nip or gap to form a cable wherein the resin forms molded fastener elements 334 and attaches to insulator tape 338 thereby insulating multiple conductive wires 336 and producing the integral fastener-cable of
In another example illustrated in
Referring now to
Simultaneously with wires 602, a band 610 of molten thermoplastic resin is introduced to nip 604 from extruder head 612. Pressure and temperature conditions in the nip cause the molten resin to envelop the wires and also cause a portion of the resin to fill hook shaped cavities 614 provided in mold roll 606. As the cooled mold roll continues to rotate, the resin and encapsulated wires remain adjacent the periphery of the mold roll until take-off rollers 618 and 620 act to strip the product 600 from the mold roll, thus extracting the now solidified hooks 622 from their respective cavities 614.
Referring now to
One alternative for controlling the vertical position of wires 602 within insulating body 632 is to provide a supporting substrate 633 beneath the wires as the molding process takes place. As illustrated in
The resulting product 600′ (
In an alternative embodiment, also illustrated in
Referring now to
Referring now to
In one particular embodiment, illustrated in
Yet another method for producing electrical cables of the present invention is illustrated in
Simultaneously with hook tape 730 and backing tape 734, a plurality of flat conductive strips (or wires of circular cross-section) is introduced between pressure rolls 736, 738 in laterally spaced apart fashion. Conductors 732 are positioned between second surface 744 of hook tape 730 and second surface 750 of backing tape 734. Pressure roll 736 has a series of protruding rings 752 arranged to contact first surface 742 of hook tape 732 only along regions 753 of the forming laminate 754 that lie between the spaced-apart conductors 732. Rolls 736 and 738 are heated and positioned to create pressure in the regions 753 corresponding to each ring 752 such that thermal bonding occurs along the contacted regions of laminate 754. The thermal bonding lines act to permanently weld hook tape 730 to backing tape 734 in a manner that electrically isolates conductors 732 from one another and insulates the conductors between the hook tape and the backing tape. Pre-formed hook tape 734 can be provided with regions 753 distinguished by flat areas (as illustrated in
In another alternative, pressure roll 736 acts as an anvil (rotary or stationary) while pressure roll 734 is ultrasonically vibrated at a frequency which causes hook tape 730 to be welded to backing tape 734 along the regions 753 where rings 752 contact hook tape 730.
Referring again to
In yet another alternative, the backing tape 734 is in the form of a second strip of hook tape, similar or identical to the hook tape 730 described above, so that the resulting electrically conductive cable has loop engageable hooks extending from opposite exposed surfaces.
It should be noted that in the adhesive laminating examples just discussed, the hooks 746 are not permanently deformed to any significant extent by their passage through the smooth pressure rollers. Rather the hooks are resilient enough to withstand the pressures applied by the unheated rolls.
As illustrated in
Again, as discussed above with reference to
Fastener tape 810 can be advantageously produced continuously and integrally of thermoplastic resin as described above, again with reference to U.S. Pat. No. 4,794,028, issued Dec. 27, 1988, to Fischer. Briefly, as illustrated, the right-hand portion of 1004 in
Other techniques for continuously and integrally forming a thermoplastic hook fastener tape are equally suitable for use with the present invention. One such technique involves the extrusion of thermoplastic resin into a gap formed between the extrusion head and the mold roll without the use of a separate pressure roll. This technique is more fully described, for example, in U.S. Pat. No. 5,441,687, issued Aug. 15, 1999, to Murasaki et. al, to which the reader is referred for further information.
In another suitable technique, stems rather than hook fastener element shaped projections are initially formed integrally with a thermoplastic base. Subsequently, the tops of the stems are shaped to form engaging heads by, e.g., contacting the stem tips with a heated roller or heating the stem tips contacting them with an unheated or cooled roller, to produce stems having heads capable of engaging complementary loops or like or unlike shaped hook fastener elements. Examples of these techniques are more fully illustrated in U.S. Pat. No. 5,077,870 issued Jan. 7, 1992 to Melbye et al. and U.S. Ser. No. 09/231,124, filed Jan. 15, 1999, respectively. The reader is referred to both of these references for further information.
In yet another suitable technique, a thermoplastic base is extruded having continuous rails of hook fastener-shaped profile. The rails, but not the base, are subsequently slit laterally at intervals along the length of the extrusion to form separate portions of the fastener-shaped rail, each portion separated from an adjacent portion by a slit. The base is then permanently stretched longitudinally to create space between adjacent portions of the fastener-shaped rails. The resulting fastener tape has rows of spaced individual hook fastener elements. Such a technique is more fully described for example, in U.S. Pat. No. 4,894,060, issued Jan. 16, 1990, to Nestegard, to which the reader is referred for further information.
As illustrated in
Referring again to
As illustrated in
In some cases, in order to prepare the surface to be conductively coated, a wetting agent is first applied at station 1030. In one example the thermoplastic resin of the fastener tape is polypropylene, and the wetting agent is a product known as C22 and available from Peacock Laboratories Inc., of Philadelphia, Pa. The C22 is mixed with water (preferably deionized) in a ratio of 14 ml. to 16 oz., respectively, and is then sprayed, as illustrated by sprayer 1032, dipped, or wiped onto the desired area of the hook fastener product.
With the wetting agent applied, the hook fastener product is then passed on to station 1040 where a sensitizing solution is applied. Again using the example of a polypropylene thermoplastic resin, one appropriate sensitizing solution is No. 93 Sensitizing Solution available from Peacock Laboratories Inc., of Philadelphia, Pa. The No. 93 Sensitizing Solution is mixed with water (preferably deionized) in a ratio of 14 ml. to 16 oz., respectively, and is then sprayed, as illustrated by sprayer 1042, dipped, or wiped onto the desired area of the hook fastener product.
After allowing the sensitizing solution to cure on the hook fastener product, e.g., approximately 60 seconds in the case of No. 93 Sensitizing Solution on polypropylene, the hook fastener product is directed to station 1050 where the treated areas are rinsed with water (preferably deionized). Rinsing is effectively accomplished by spraying, as illustrated by sprayer 1052, dipping, or wiping the desired area with the rinse water.
The hook fastener product is then directed to station 1060 where it is saturated with a silvering solution to apply the electrically conductive coating. In the case of a hook fastener product of polypropylene, an appropriate silvering solution is HE-300 available from Peacock Laboratories Inc., of Philadelphia, Pa. The HE-300 silvering solution is made up of three constituent solutions including HE-300 Silver Solution “A”, HE-300 Activator Solution “B” and HE-300 Reducer solution “C”. All three components of the silvering solution are applied simultaneously by a dual-nozzle spray gun 1062. A first nozzle 1064 of spray gun 1062 is supplied from a tank containing the following mixture: Equal amounts of HE-300 Silver Solution “A” and HE-300 Activator Solution “B” each mixed with water (preferably deionized) in a ratio of 14 ml. to 8 oz., respectively. To avoid a potentially explosive reaction in the mixing tank, it is preferable to mix each of the concentrated HE-300 “A” and “B” solutions with the water, as opposed to mixing the concentrated solutions directly together.
Simultaneously, with the spraying from the first nozzle 1024, second nozzle 1066 sprays a solution supplied from a supply tank in which HE-300 Silver Reducer has been mixed with water (preferably deionized) in a ratio of 14 ml. to 16 oz.
The dual nozzle spray gun 1062 operates to simultaneously spray equal amounts of the mixtures from both spray nozzles 1064, 1066. As illustrated, nozzles 1064 and 1066 are biased toward each other so that their respective outputs mix at approximately their point of contact with hook fastener product. The result is that the separate streams combine approximately as the streams contact the surface of the hook fastener product. The area to be coated is saturated with the spray from dual nozzle spray gun 1062 until the surface changes to a gray/gold color. At this point, the conductive coating is sufficiently complete.
In another embodiment, the formed hook fastener product is covered by a masking material prior to the silvering process. As illustrated in
In yet another embodiment, a piercing station 1080 is provided in which the formed hook fastener tape is pierced, e.g., by stakes 1082, to form through-holes that extend from a first to a second broad surface of the fastener tape base. Subsequent silvering of the hook fastener tape coats the surfaces defining the through-holes with conductive material. These conductive through-hole surfaces provide passageways for electrical signals to be passed from a first to a second surface of the hook fastener tape.
In one example, illustrated in
The process described above with reference to
Cable 1200 has electrical connectors 1222 at its terminal longitudinal ends. Conductive bands 1208 allow for passage of electrical signals between the two terminal connectors 1222 while hook fastener elements 1206 allow the cable to be releasably secured to a surface (not shown) equipped with complementary fastening material, e.g., a loop material. Also, as illustrated in
In the example illustrated in
In the example illustrated in
As illustrated in
Furthermore, the flexible circuits 1400 and 1500 of
Referring now also to
In a particularly advantageous embodiment, portions 1540 of film 1530 are removed, e.g., by punching or piercing, at desired locations so that after lamination, portions 1542 of conductive path 1308, 1409, 1509 are accessible for, e.g., electrical connection(s). When adhesive is used in the lamination process, it is desirable that the adhesive 1538 be applied to surface 1536 of film 1530 prior to the removal, e.g., punching and/or piercing, process so that after lamination the adhesive does not interfere with electrical connection(s) to the exposed portions 1540 of conductive path 1308, 1409, 1509.
As illustrated particularly in
In one embodiment, illustrated in
One example of a conductive loop material 1610 suitable for use in producing back-to-back conductive fastener 1600 is a product marketed under the tradename HI-MEG BRAND Loop tape and available from Velcro U.S.A. Corp., Manchester, N.H. The conductive nature of at least the outer surface of loop material 1610 remains substantially unaffected by the temperatures of the molding process because the pressure roll is typically either unheated or cooled. Alternatively, loop material 1610 may be initially a noncoated, nonconductive loop material that is fed into nip 1004, and subsequently both the hook and loop surfaces of the resulting product can be conductively coated in a post-forming operation.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, as an alternative to the masking process described above for producing a desired pattern of electrically conductive material on a hook fastener substrate, a removal process can be employed. Such a removal process can be implemented by first providing a hook fastener tape having one or both broad surfaces coated with a conductive layer as described above with reference to
Furthermore, and quite notably, many of the above described techniques can be combined to produce fasteners having combinations of the various described features as desired for the particular application of the resulting electricity conducting fastener. For example, the circuit printing techniques and resulting products described with reference to
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.
The entire contents of each of the references to which the reader has been referred to for further information above are hereby fully incorporated by reference.
Claims
1-67. (canceled)
68. A method of forming an electrical cable, the method comprising:
- introducing a plurality of longitudinally extending electrical conductors into a gap defined adjacent a pressure roll; and
- introducing moldable resin into the gap under conditions that cause the resin to encapsulate the electrical conductors;
- wherein the pressure roll defines a plurality of recesses and the electrical conductors are substantially aligned with the recesses.
69. The method of claim 68 wherein the gap is a nip defined between a mold roll and counter-rotating pressure roll.
70. The method of claim 69 further comprising solidifying the resin on a peripheral surface of the mold roll and stripping the solidified resin and encapsulated electrical conductors from the mold roll.
71. The method of claim 69 further comprising molding fastener stems integrally molded with and extending from a resin base.
72. The method of claim 71 wherein molding fastener stems comprising molding fastener stems with integrally molded loop engageable heads.
73. The method of claim 68 wherein the recesses are substantially circumferentially extending grooves.
74. The method of claim 73 wherein the grooves extend around a diameter of the pressure roll.
75. The method of claim 68 further comprising introducing the resin and encapsulated electrical conductors into a nip defined between a second pressure roll and a mold roll; and
- molding fastener stems on the resin encapsulating the electrical conductors.
76. The method of claim 68 further comprising guiding the electrical conductors into alignment with the grooves using a guide plate.
77. The method of claim 68 wherein each groove is sized to receive the aligned conductors.
78. The method of claim 68 wherein the conductors comprise wire.
79. The method of claim 68 wherein introducing the moldable resin into the nip comprises introducing the moldable resin into the nip such that the resin separates adjacent electrical conductors.
80. The method of claim 68 further comprising controlling the lateral position of the electrical conductors by introducing a supporting substrate into the nip between the electrical conductors and the pressure roll.
81. The method of claim 80 wherein the supporting substrate spaces the electrical conductors from the pressure while allowing the resin to fill the grooves.
82. A method of forming an electrical cable, the method comprising:
- introducing a plurality of longitudinally extending electrical conductors into a nip defined between a mold roll and a pressure roll;
- introducing moldable resin into the nip under conditions causing the resin to enter mold cavities defined in the peripheral surface of the mold roll; and
- attaching the electrical conductors to the resin;
- wherein the electrical conductors have sufficient flexibility to conform to a peripheral surface of the mold roll, the pressure roll defines a plurality of substantially circumferentially extending grooves, and the electrical conductors are introduced into the nip substantially aligned with the grooves.
83. The method of claim 82 further comprising solidifying the resin on a peripheral surface of the mold roll and then stripping the resin and attached electrical conductors from the mold roll.
84. The method of claim 83 wherein solidifying the resin comprises forming fastener stems integrally molded with and extending from a resin base.
85. The method of claim 84 wherein forming fastener stems comprising molding fastener stems with integrally molded loop engageable heads.
86. The method of claim 82 further comprising guiding the electrical conductors into alignment with the grooves using a guide plate.
87. The method of claim 82 wherein each groove is sized to receive the aligned conductor.
88. The method of claim 82 wherein introducing the moldable resin into the nip comprises introducing the moldable resin into the nip such that the resin separates adjacent electrical conductors.
89. The method of claim 82 wherein attaching the electrical conductors to the resin comprises encapsulating the electrical conductors in the resin.
90. A method of forming a laminate with fastener elements, the method comprising:
- introducing a substrate into a nip defined between a mold roll and a pressure roll, the mold roll including mold cavities defined in a peripheral surface of the mold roll;
- introducing moldable resin into the nip under conditions such that at least a portion of the resin enters the mold cavities while encapsulating at least surface features of the substrate with the resin;
- forming features integrally molded with and extending from a resin base;
- solidifying the resin to form a laminate including the resin base and the substrate; and then
- removing the laminate from the mold roll;
- wherein the pressure roll defines a groove that aids in aligning the substrate in the nip.
91. The method of claim 90 wherein the substrate comprises an electrical conductor.
92. The method of claim 90 wherein introducing the substrate comprises aligning the electrical conductor with the groove.
93. The method of claim 90 wherein the pressure roll defines a plurality of grooves and introducing a substrate comprises introducing multiple parallel substrates into the nip with each of the parallel substrates aligned with a corresponding one of the plurality of grooves.
94. The method of claim 93 wherein the multiple parallel substrates each comprise an electrical conductor.
95. The method of claim 94 further comprising guiding multiple electrical conductors into alignment with the grooves using a guide plate.
96. The method of claim 94 wherein the conductors comprise wire.
97. The method of claim 90 wherein forming the features comprise forming stems of fastener elements.
98. The method of claim 97 wherein forming the stems comprises molding loop engageable heads on the fastener stems.
99. The method of claim 90 wherein the groove substantially circumferentially extending around a diameter of the pressure roll.
100. The method of claim 90 wherein solidifying the resin comprises solidifying the resin on the mold roll with the resin and substrate remaining on the peripheral surface of the mold roll through a partial rotation of the mold roll.
Type: Application
Filed: Nov 7, 2005
Publication Date: Mar 9, 2006
Applicant:
Inventors: Christopher Gallant (Nottingham, NH), Michel Labrecque (Manchester, NH), Mark Clarner (Concord, NH), John Demain (Olney)
Application Number: 11/268,421
International Classification: A63B 37/00 (20060101);