Patent Description:
It may be desirable to form items such a bags, clothing, and other items from intertwined strands of material. For example, woven or knitted fabric or braided strands may be used in forming portions of an item.

In some situations, it may be desirable to form items using warp knit fabric. Warp knit fabrics allow for a variety of fabric constructions and can be knitted into three- dimensional structures with multiple layers.

Warp knit fabrics sometimes include inserted weft and/or warp threads. The inserted weft and warp threads lie flat in the knitted fabric and can provide strength and rigidity to the fabric.

In conventional warp knitting machines, weft threads are inserted using a weft thread carrier that holds each weft thread across the entire width of the knitting machine. Weft threads that are inserted in the fabric with this type of equipment have a fixed path, typically spanning the entire width of the fabric.

Having weft threads restricted to one width and one pattern in a warp knit fabric can place undesirable limitations on the layout and design of the warp knit fabric. These limitations are especially cumbersome when forming fabrics with conductive signal paths and conductive regions. For example, fixed-pattern weft threads in a warp knit fabric cannot be used to form conductive regions of different shapes, sizes, and patterns in the fabric.

It would therefore be desirable to be able to form improved fabric constructions for warp knit fabrics.

<CIT> discloses a double knitted fabric.

<CIT> discloses an electrically conductive fabric and manufacturing method and apparatus thereof.

<CIT> discloses a method for producing a textile and a textile for energy conversion.

<CIT> discloses a warp knit wrappable sleeve with extendable electro-functional yarns and method of construction thereof.

<CIT> discloses a spacer fabric for cushioning.

<CIT> discloses an electric fence with an improved conducting network.

<CIT> discloses a warp knitted fabric having partial extensibility and searchability.

<CIT> discloses a fabric product and sensing fabric made thereof comprising a top and lower layer, the top layer comprising a series of alternate insulating strips and conductive strips, the bottom layer having low conductivity properties, which comprises cross-yarns of low conductivity material extending from the bottom layer to the conductive strips of the top layer.

<CIT> discloses a flat warp knit spacer fabric having a complex shape, wherein a electrically conductive thread, which is inlayed in the weft direction in multiple zones having varying widths.

Preferred advantageous embodiments thereof are defined by the sub-features of the dependent claims.

An item may include fabric or other materials formed from intertwined strands of material. The strands of material may include non-conductive strands and conductive strands. The strands may are intertwined by a warp knitting machine to produce a warp knit fabric. The warp knit fabric includes intertwined warp strands and weft insertion strands that are inserted amongst the warp strands.

The weft insertion strands extend across less than all of the warp strands in the warp knit fabric. The weft insertion strands may include parallel segments in the fabric that each extend across a different portion of the warp strands. The segments of weft insertion strands may have different widths relative to one another and relative to the width of the fabric. In examples not forming part of the invention, some weft insertion strands may extend across the entire width of the fabric whereas other weft insertion strands may extend across only a portion of the width of the fabric.

To form a warp knit fabric having weft insertion strands of variable width, weft insertion strands may be inserted into a warp knitting machine using a weft insertion device that is positioned by a computer-controlled positioner. The computer-controlled positioner may move the weft insertion device across a desired width of the fabric corresponding to the desired width of the weft strand in the fabric. The weft insertion device may feed a weft strand into the warp knitting machine as the weft insertion device moves the desired distance across the warp knitting machine. If desired, multiple weft insertion devices may be used in parallel to insert multiple weft strands into the fabric during knitting. The weft insertion devices may be independently controlled and, if desired, may produce different weft strand patterns in the fabric.

In other arrangements, the weft insertion strands may be preloaded onto a conveyor surface in a pattern corresponding to the pattern to be created in the warp knit fabric. For example, the weft insertion strands may be wrapped around a series of posts on the conveyor surface to create parallel segments having different widths. They conveyor may feed each segment into the warp knitting machine to thereby embed weft insertion strands of variable widths in the warp knit fabric.

The warp knitting machine may be a tricot knitting machine, a single needle bar Raschel knitting machine, a double needle bar knitting machine, or other suitable knitting machine. In a double needle bar Raschel knitting machine, a multi-layer fabric may be produced. For example, a warp knit textile having first and second layers and a spacer layer joining the first and second layers may be produced. If desired, any one or more of the layers in a multi-layer warp knit textile may include weft insertion fibers having variable paths.

Strands of material may be incorporated into strand-based items such as strand- based item <NUM> of <FIG>. Item <NUM> may be an electronic device or an accessory for an electronic device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user's head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which fabric-based item <NUM> is mounted in a kiosk, in an automobile, airplane, or other vehicle, other electronic equipment, or equipment that implements the functionality of two or more of these devices. If desired, item <NUM> may be a removable external case for electronic equipment, may be a strap, may be a wrist band or head band, may be a removable cover for a device, may be a case or bag that has straps or that has other structures to receive and carry electronic equipment and other items, may be a necklace or arm band, may be a wallet, sleeve, pocket, or other structure into which electronic equipment or other items may be inserted, may be part of a chair, sofa, or other seating (e.g., cushions or other seating structures), may be part of an item of clothing or other wearable item (e.g., a hat, belt, wrist band, headband, etc.), or may be any other suitable strand-based item.

Strands in strand-based item <NUM> may form all or part of a housing wall for an electronic device, may form internal structures in an electronic device, or may form other strand-based structures. Strand-based item <NUM> may be soft (e.g., item <NUM> may have a fabric surface that yields to a light touch), may have a rigid feel (e.g., the surface of item <NUM> may be formed from a stiff fabric), may be coarse, may be smooth, may have ribs or other patterned textures, and/or may be formed as part of a device that has portions formed from non-fabric structures of plastic, metal, glass, crystalline materials, ceramics, or other materials.

Item <NUM> includes intertwined strands <NUM>. The strands may be intertwined using strand intertwining equipment such as weaving equipment, knitting equipment, braiding equipment, or equipment that intertwines strands by entangling the strands with each other in other ways (e.g., to form felt). Intertwined strands <NUM> may, for example, form woven or knitted fabric or other fabric (i.e., item <NUM> may be a fabric-based item), a braided cord, etc..

Strands <NUM> may be single-filament strands or may be threads, yarns, or other strands that have been formed by intertwining multiple filaments of material together. Strands <NUM> may be formed from polymer, metal, glass, graphite, ceramic, natural fibers such as cotton, bamboo, wool, or other organic and/or inorganic materials and combinations of these materials. Strands <NUM> may be insulating or conductive.

Conductive coatings such as metal coatings may be formed on non-conductive strands (e.g., plastic cores) to make them conductive and strands such as these may be coated with insulation or left bare. Reflective coatings such as metal coatings may be applied to strands <NUM> to make them reflective. Strands <NUM> may also be formed from single-filament metal wire, multifilament wire, or combinations of different materials.

Strands <NUM> may be conductive along their entire length or may have conductive segments (e.g., metal portions that are exposed by locally removing insulation or that are formed by adding a conductive layer to a portion of a non-conductive strand. Threads and other multifilament yarns that have been formed from intertwined filaments may contain mixtures of conductive fibers and insulating fibers (e.g., metal strands or metal coated strands with or without exterior insulating layers may be used in combination with solid plastic fibers or natural fibers that are insulating).

Item <NUM> may include additional mechanical structures <NUM> such as polymer binder to hold strands <NUM> together, support structures such as frame members, housing structures (e.g., an electronic device housing), and other mechanical structures.

Circuitry <NUM> may be included in item <NUM>. Circuitry <NUM> may include components that are coupled to strands <NUM>, components that are housed within an enclosure formed by strands <NUM>, components that are attached to strands <NUM> using welds, solder j oints, adhesive bonds (e.g., conductive adhesive bonds), crimped connections, or other electrical and/or mechanical bonds. Circuitry <NUM> may include metal structures for carrying current, integrated circuits, discrete electrical components such as resistors, capacitors, and inductors, switches, connectors, light-emitting components such as light-emitting diodes, audio components such as microphones and speakers, vibrators, solenoids, piezoelectric devices, and other electromechanical devices, connectors, microelectromechanical systems (MEMs) devices, pressure sensors, light detectors, proximity sensors, force sensors, moisture sensors, temperature sensors, accelerometers, gyroscopes, compasses, magnetic sensors, touch sensors, and other sensors, components that form displays, touch sensors arrays (e.g., arrays of capacitive touch sensor electrodes to form a touch sensor that detects touch events in two dimensions), and other input-output devices. Circuitry <NUM> may also include control circuitry such as non-volatile and volatile memory, microprocessors, application-specific integrated circuits, system-on-chip devices, baseband processors, wired and wireless communications circuitry, and other integrated circuits.

Item <NUM> may interact with electronic equipment or other additional items <NUM>. Items <NUM> may be attached to item <NUM> or item <NUM> and item <NUM> may be separate items that are configured to operate with each other (e.g., when one item is a case and the other is a device that fits within the case, etc.). Circuitry <NUM> may include antennas and other structures for supporting wireless communications with item <NUM>. Item <NUM> may also interact with strand- based item <NUM> using a wired communications link or other connection that allows information to be exchanged.

In some situations, item <NUM> may be an electronic device such as a cellular telephone, computer, or other portable electronic device and strand-based item <NUM> may form a case or other structure that receives the electronic device in a pocket, an interior cavity, or other portion of item <NUM>. In other situations, item <NUM> may be a wrist-watch device or other electronic device and item <NUM> may be a strap or other strand-based item that is attached to item <NUM>. In still other situations, item <NUM> may be an electronic device, strands <NUM> may be used in forming the electronic device, and additional items <NUM> may include accessories or other devices that interact with item <NUM>.

If desired, magnets and other structures in items <NUM> and/or <NUM> may allow items <NUM> and <NUM> to interact wirelessly. One item may, for example, include a magnet that produces a magnetic field and the other item may include a magnetic switch or magnetic sensor that responds in the presence of the magnetic field. Items <NUM> and <NUM> may also interact with themselves or each other using pressure-sensitive switches, pressure sensors, force sensors, proximity sensors, light-based sensors, interlocking electrical connectors, etc..

The strands that make up item <NUM> are intertwined using any suitable strand intertwining equipment. For example, strands <NUM> may be woven together to form a fabric. The fabric may have a plain weave, a satin weave, a twill weave, or variations of these weaves, may be a three-dimensional woven fabric, or may be other suitable woven fabric. If desired, the strands that make up item <NUM> may be intertwined using knitting equipment, braiding equipment, or other strand intertwining equipment. Item <NUM> may also incorporate more than one type of fabric or intertwined strand-based material (e.g., item <NUM> may include both woven and knitted portions).

The strands that make up item <NUM> are intertwined to form a fabric such as illustrative fabric <NUM> of <FIG>. Fabric <NUM> may include strands <NUM>. Strands <NUM> may be formed from conductive and/or insulating materials. As an example, fabric may be formed from insulating strands interspersed with conductive strands. In the illustrative configuration of <FIG>, fabric <NUM> is a warp knit fabric having columns of warp strands <NUM>-<NUM> that zigzag along the length L of fabric <NUM>. Each warp strand <NUM>-<NUM> has a number of loops, with each loop securing a loop of an adjacent strand from a previous row. For example, the loops of row 22B in fabric <NUM> secure the loops of row 22A in fabric <NUM>.

According to the invention, additional strands are inserted into a warp knit fabric. For example, as shown in <FIG>, fabric <NUM> includes weft strands <NUM>-<NUM> and warp strands <NUM>-<NUM> that are inserted into the intertwined warp strands <NUM>-<NUM>. Weft strands <NUM>-<NUM> that are inserted across the width W of fabric <NUM> are referred to as weft insertion strands. Warp strands <NUM>-<NUM> that are inserted along the length L of fabric <NUM> may sometimes be referred to as warp insertion strands.

In contrast to woven fabrics in which weft threads have a wave-like shape due to the over-under weaving pattern, weft insertion strands <NUM>-<NUM> are able to lie flat in fabric <NUM> because the strands are inserted into fabric <NUM> between rows of stitching. For example, as shown in <FIG>, weft insertion strand <NUM>-<NUM> is inserted into fabric <NUM> between row A of stitches and row B of stiches.

Weft insertion strands <NUM>-<NUM> and warp insertion strands <NUM>-<NUM> may be formed from the same material as warp strands <NUM>-<NUM> or may be formed from a different material. For example, warp strands <NUM>-<NUM> may be insulating strands while weft insertion strands <NUM>-<NUM> are conductive strands and warp insertion strands <NUM>-<NUM> may be conductive strands. In examples not forming part of the invention, warp strands <NUM>-<NUM> may be conductive strands while weft insertion strands <NUM>-<NUM> and/or warp insertion strands <NUM>-<NUM> may be insulating strands.

The distance spanned by a weft insertion strand across a fabric is referred to herein as the "width" of the weft insertion strand. Because a single weft strand may form multiple rows in a fabric, the width of a weft insertion strand may sometimes refer to the width of a given row formed by a segment of a weft insertion strand. For example, weft strand <NUM>-<NUM>' and weft-strand <NUM>-<NUM>" may be formed from two separate weft strands or may be formed from a single weft strand that extends back and forth across the fabric. In other words, a single weft strand may have multiple widths, with each width corresponding to a respective row formed by a segment of the weft strand.

To accommodate different fabric patterns and designs, fabric <NUM> may include weft insertion strands <NUM>-<NUM> that follow a variable pattern in fabric <NUM>. For example, weft insertion strands <NUM>-<NUM> may span various distances across the width of fabric <NUM>, wherein weft insertion strands <NUM>-<NUM>, <NUM>-<NUM>' and <NUM>-<NUM>" extend across less than all of warp fibers <NUM>-<NUM> in accordance with the invention. In the illustrative example of <FIG>, strand <NUM>-<NUM>' has a width W1 that is less than width W and strand <NUM>-<NUM>" has a width W2 that is less than width W of fabric <NUM> and width W1 of strand <NUM>-<NUM>. Varying the width of weft insertion strands <NUM>-<NUM> may allow patterns that would otherwise not be possible in a warp knit fabric.

Illustrative equipment and operations of the type that may be involved in forming fabric-based items that include weft insertion strands of variable patterns are shown in <FIG>.

As shown in <FIG>, the equipment of <FIG> may be provided with strands from strand source <NUM>. The strands provided by strand source <NUM> may be single-strand filaments or may be threads, yarns, fibers, or other strands that have been formed by intertwining single-strand filaments. Strands may be formed from polymer, metal, glass, graphite, ceramic, natural materials such as cotton or bamboo, or other organic and/or inorganic materials and combinations of these materials. Conductive coatings such as metal coatings may be formed on non-conductive strand cores. Strands may also be formed from single filament metal wire or stranded wire. Strands may be insulating or conductive. Strands may be conductive along their entire length or may have conductive segments (e.g., metal portions that are exposed by locally removing polymer insulation from an insulated conductive fiber). Threads and other multi-strand bundles that have been formed from intertwined filaments may contain mixtures of conductive strands and insulating strands (e.g., metal strands or metal coated strands with or without exterior insulating layers may be used in combination with solid plastic strands or natural strands that are insulating).

Strand source <NUM> may provide warp strands (e.g., warp strands <NUM>-<NUM> of <FIG>) to intertwining equipment <NUM> and weft strands (e.g., weft insertion strands <NUM>-<NUM> of <FIG>) to weft strand insertion equipment <NUM>. Weft strand insertion equipment <NUM> may feed weft strands <NUM>-<NUM> into intertwining equipment <NUM>.

Warp strands <NUM>-<NUM> (<FIG>) from strand source <NUM> and weft strands <NUM>-<NUM> from weft strand insertion equipment <NUM> may be intertwined using intertwining equipment <NUM> to produce fabric <NUM>. Equipment <NUM> may include knitting equipment such as tricot knitting equipment, Raschel knitting equipment (e.g., single needle bar or double needle bar Raschel knitting equipment), Milanese knitting equipment, or other suitable equipment for intertwining strands from strand source <NUM>. Equipment <NUM> may be automated. For example, equipment <NUM> may include computer-controlled actuators that manipulate and intertwine fibers from source <NUM>. Intertwining equipment <NUM> may be configured to produce three-dimensional fabric structures (e.g., fabrics with potentially complex multi-layer structures). For example, intertwining equipment <NUM> may include knitting equipment that produces three-dimensional structures, a three-dimensional weaving machine, tools for producing three-dimensional braided fabrics, etc..

Weft strand insertion equipment <NUM> may include one or more feeders that feed weft strands <NUM>-<NUM> into warp knitting machine <NUM> during knitting. If desired, weft strand insertion equipment <NUM> may be automated. For example, equipment <NUM> may include computer-controlled actuators that control when weft strands <NUM>-<NUM> are inserted into knitting machine <NUM> and that controls the width spanned by each weft strand <NUM>-<NUM> in fabric <NUM>. The widths spanned by weft strands <NUM>-<NUM> may be predetermined prior to knitting or may be determined and adjusted during the knitting process. Weft strand insertion equipment <NUM> may produce rows of weft strands <NUM>-<NUM> with variable widths in fabric <NUM>.

As shown in <FIG>, fabric <NUM> that includes inserted weft strands <NUM>-<NUM> may be processed using additional tools and assembly equipment <NUM>. Equipment <NUM> may be used in processing strands <NUM>. Equipment <NUM> may be used in forming electrical connections between strands <NUM> and attaching electronic components such as electronic components in circuitry <NUM> of <FIG> to strands such as conductive strands <NUM>. For example, equipment <NUM> may be used to attach electrical components to strands <NUM> using solder j oints, crimped metal connections, welds, conductive adhesive, or other conductive attachment structures. The electrical components that are attached to strands in this way may include light-emitting components, integrated circuits, light-emitting diodes, light-emitting diodes that are packaged with transistor-based circuitry such as communications circuitry and/or light-emitting diode driver circuitry that allows each component to operate as a pixel in a display, discrete components such as resistors, capacitors, and inductors, audio components such as microphones and/or speakers, sensors such as touch sensors (with or without co-located touch sensor processing circuitry), accelerometers, temperature sensors, force sensors, microelectromechanical systems (MEMS) devices, transducers, solenoids, electromagnets, pressure sensors, light-sensors, proximity sensors, buttons, switches, two-terminal devices, three-terminal devices, devices with four or more contacts, etc. Electrical connections for attaching electrical components to strands <NUM> using equipment <NUM> may be formed using solder, conductive adhesive, welds, molded package parts, mechanical fasteners, wrapped strand connections, press-fit connections, crimped connections (e.g., bend metal prong connections), and other mechanical connections, portions of liquid coatings (e.g., metallic paint, conductive adhesive, etc.) that are selectively applied to strands <NUM> using equipment <NUM>, or using any other suitable arrangement for forming an electrical short between conductive structures.

Equipment <NUM> may be used to attach fabric <NUM> to housing structures formed from plastic, metal, glass, or other materials. Fabric <NUM> may be sewn, cut, and otherwise incorporated into fabric-based items to form a finished fabric-based item (e.g., electronic device <NUM>).

<FIG> is a perspective view of illustrative knitting equipment that may be used to knit fabric <NUM>. As shown in <FIG>, knitting equipment <NUM> may include guide bar <NUM> having a number of guides <NUM>. Each warp thread <NUM>-<NUM> may be threaded through a respective one of guides <NUM>. Needle bar <NUM> may include a number of needles <NUM>. All of the needles <NUM> in needle bar <NUM> may move in unison. Needles <NUM> may be bearded needles having beards 38B or may be any other suitable type of knitting needle (e.g., latch needle, compound needle, carbine needle, etc.).

Loops are made between adjacent warp strands <NUM>-<NUM> by moving various components of knitting machine <NUM>. Guide bar <NUM> is configured to move back and forth between needles <NUM> along direction <NUM>. This movement is sometimes referred to as a swing. Guide bar <NUM> is also configured to move laterally in direction <NUM>, either in front of or behind needles <NUM>. This movement is sometimes referred to as a shog. <FIG>, <FIG>, and <FIG> show how loops are formed in a warp knit fabric using knitting equipment of the type shown in <FIG>.

As shown in <FIG>, loop formation begins with guide <NUM> swinging in direction <NUM> from the front of machine <NUM> (e.g., opposite the open side of needles <NUM>) to the back of machine <NUM> (e.g., on the open side of needles <NUM>) to bring warp thread <NUM>-<NUM> between adjacent needles <NUM> to the back of machine <NUM>. At this stage, closing structure <NUM> is down such that beard 38B of needle <NUM> is open.

In <FIG>, guide <NUM> is shogged laterally behind needle <NUM> in direction <NUM> to overlap warp strand <NUM>-<NUM> behind needle <NUM>. Following this lateral shog, guide <NUM> swings from back to front in direction <NUM>, bringing warp thread <NUM>-<NUM> back between needles <NUM> (e.g., on the opposite side of needle <NUM> as the front-to-back swing of <FIG>).

In <FIG>, closing structure <NUM> has moved upwards in direction <NUM> to trap newly made loop <NUM> (e.g., the loop around needle <NUM> formed from the overlap step of <FIG>) in needle <NUM>. Closed needle <NUM> then moves downward in direction <NUM> to pull new loop <NUM> in direction <NUM> through a previously made loop such as old loop <NUM>, which is wrapped around a lower portion of needle <NUM>. After new loop <NUM> has been pulled through old loop <NUM>, sinkers such as sinker <NUM> may be moved backwards in direction <NUM> to release old loop <NUM> (a process sometimes referred to as knock-over). After disengaging the old loops from needle <NUM>, sinker <NUM> may move forward in direction <NUM> to secure fabric <NUM> prior to needles <NUM> rising for the next cycle of loop formation.

The knitting equipment of <FIG>, <FIG>, <FIG>, and <FIG> is merely illustrative. Similar movements may apply with various types of knitting machines (e.g., tricot machines, Raschel machines, machines with compound needles, bearded needles, or other suitable type of needle, etc.).

<FIG> is a cross-sectional side view of a warp knit fabric <NUM> having inserted weft strands. As shown in <FIG>, weft insertion strands <NUM>-<NUM> may be inserted into fabric <NUM> between previously formed loops <NUM> of fabric <NUM> prior to pulling a new loop (e.g., a new loop such as loop <NUM> of <FIG>) through previously formed loop <NUM>. Once the new loops are pulled through the old loops, warp insertion strands <NUM>-<NUM> may be integrated into fabric <NUM>.

<FIG> is a perspective view of illustrative equipment that may be used to insert weft strands <NUM>-<NUM> into fabric <NUM> during knitting. As shown in <FIG>, weft strand insertion equipment <NUM> may include a conveyor belt structure such as conveyor <NUM> having a number of structures <NUM> (e.g., hooks, pins, posts, etc.) around which weft strands <NUM>-<NUM> are wrapped. Hooks <NUM> hold each weft strand segment <NUM> parallel to the width W of fabric <NUM>. To insert weft strand segments <NUM> into fabric <NUM>, rollers <NUM> rotate in direction <NUM> which in turn moves conveyor surface <NUM> in direction <NUM>. Weft segments <NUM> are released from conveyor <NUM> and placed cross-wise into fabric <NUM> (see, e.g., <FIG>).

A shown in <FIG>, the width of weft strand segments <NUM> is determined by the spacing between posts <NUM>. If desired, equipment <NUM> may have a uniform spacing between posts <NUM> to form weft segments of uniform width, or equipment <NUM> may have variable spacing between posts <NUM> to form weft segments with variable width, as shown in <FIG>. For example, a distance D1 may separate one pair of opposing posts <NUM>, while a distance D2 (e.g., a distance less than D1) may separate another pair of opposing posts.

If desired, the positions of posts <NUM> on conveyor surface <NUM> may be fixed or the positions may be adjustable. In either case, the weft insertion strand <NUM>-<NUM> may be pre-loaded onto conveyor surface <NUM> in a particular pattern. The pattern in which weft strand <NUM>-<NUM> is placed on conveyor surface <NUM> may correspond to the pattern to be created in fabric <NUM> with weft strand <NUM>-<NUM>. For example, the distances D1 and D2 between neighboring pairs of posts <NUM> on conveyor surface <NUM> may create first and second weft insertion segments <NUM> in fabric <NUM> having widths D1 and D2.

The example of <FIG> in which weft insertion equipment <NUM> includes a conveyor system on which the pattern of weft insertion strands <NUM>-<NUM> is pre-loaded prior to inserting the weft strands <NUM>-<NUM> in fabric <NUM> is merely illustrative. If desired, weft insertion equipment <NUM> may include computer-controlled weft strand positioning equipment that precisely moves and positions weft strands in fabric <NUM>. This type of arrangement is shown in <FIG>.

In the illustrative example of <FIG>, fabric <NUM> is a multi-layer fabric having a spacer layer <NUM> interposed between first and second outer layers 82A and 82B. Multi-layer fabrics of this type may, for example, be formed using Raschel double-needle bar machine in which threaded guide bars form outer layers 82A and 82B and an additional threaded guide bar is used to attach outer layer 82A and 82B with spacer layer <NUM>.

In some embodiments, the spacer construction of <FIG> may be used to form a touch-sensitive textile. Each outer layer 82A and 82B may include a set of conductive strands. The spacer layer may compress or deform in response to a touch on the textile, which, in some cases, causes the distance between conductive strands in layer 82A to come closer to the conductive strands in layer 82B. The change in distance between the conductive strands may cause a change in capacitance between the conductive strands, which may be monitored by a sensing circuit. If desired, a force associated with the touch may be determined based on the change in capacitance.

As shown in <FIG>, weft strand positioning equipment <NUM> may include a feeder <NUM> (sometimes referred to as a carrier, a weft insertion device, or weft strand positioner) that feeds weft strands <NUM>-<NUM> into fabric <NUM> during weaving. The location at which weft strands <NUM>-<NUM> are inserted into fabric <NUM> may be similar to that of <FIG> and <FIG> (e.g., between previously formed loops and newly wrapped strands to be looped with previously formed loops). In contrast to <FIG> where the pattern of weft strands <NUM>-<NUM> is formed on equipment <NUM> prior to insertion, equipment <NUM> of <FIG> produces the pattern of weft strands <NUM>-<NUM> as the weft strands are inserted into fabric <NUM>. For example, rather than feeding knitting machine <NUM> a stretched weft strand that is stretched between two hooks, feeder <NUM> may move across knitting machine <NUM> along direction <NUM> while feeding weft strand <NUM>-<NUM> into fabric <NUM> as knitting machine <NUM> knits fabric <NUM>.

Feeder <NUM> may be controlled by computer-controlled positioner <NUM>. If desired, computer-controlled positioner <NUM> may synchronize the movement and placement of feeder <NUM> with the operation of knitting machine <NUM> such that the pattern of weft insertion strands <NUM>-<NUM> can be customized and adjusted during knitting without requiring any change in operation of knitting machine <NUM>.

Computer-controlled positioner <NUM> manipulates feeder <NUM> to insert segments <NUM> of weft strands <NUM>-<NUM> in fabric <NUM>. As shown in <FIG>, weft segments <NUM> may have different widths and may span different portions of fabric <NUM>. The width <NUM> of a given segment <NUM> in fabric <NUM> may be determined by the movement of weft insertion equipment <NUM>. For example, to produce a segment of width <NUM> in fabric <NUM>, computer-controlled positioner <NUM> may move insertion device <NUM> across width <NUM> while placing weft segment <NUM> into knitting machine <NUM>. The weft segment is integrated into fabric <NUM> as knitting machine <NUM> forms loops with warp strands <NUM>-<NUM>.

The example of <FIG> in which weft strand positioning equipment <NUM> includes one feeder <NUM> is merely illustrative. If desired, weft strand positioning equipment <NUM> may include multiple feeders <NUM>. For example, one feeder <NUM> may feed weft strands <NUM>-<NUM> to layer 82A while another feeder <NUM> feeds weft strands <NUM>-<NUM> to layer 82B. If desired, weft strands <NUM>-<NUM> of layer 82A and weft strands <NUM>-<NUM> of layer 82B may be conductive and may overlap one another. The overlapping regions of conductive weft strands may, for example, form sensor electrodes as part of a touch sensor and/or force sensor in fabric <NUM>.

If desired, multiple feeders <NUM> may be used for any one or more of layers 82A, 82B, and 82C. This type of arrangement is shown in <FIG>. As shown in <FIG>, weft insertion equipment <NUM> may include multiple feeders such as feeder 84A controlled by positioner 86A and feeder 84B controlled by positioner 86B. Feeders 84A and 84B may operate independently of one another to create multiple regions <NUM> of weft segments <NUM> in fabric <NUM>. Because regions <NUM> of weft segments <NUM> are created independently of one another, each region <NUM> may have a different pattern of weft segments. The widths of segments <NUM> within a given region <NUM> may be fixed or may be variable.

The example of <FIG> in which two feeders <NUM> are used to independently insert different weft strands <NUM>-<NUM> in fabric <NUM> is merely illustrative. If desired, one, two, three, four, or more than four feeders <NUM> may be used to insert and control the width of weft segments <NUM> in fabric <NUM>. The ability to insert weft segments <NUM> with variable widths and patterns allows for the creation of regions <NUM> having different shapes, sizes, and functions in fabric <NUM>. Regions <NUM> may create an aesthetically pleasing design in fabric <NUM> and/or may be used for functional purposes (e.g., to create different patterns, shapes, and sizes of touch-sensitive and/or force-sensitive regions in fabric <NUM>).

<FIG>, <FIG>, <FIG>, and <FIG> show various patterns that can be made with a weft insertion strand using the equipment and methods described in <FIG>.

In the example of <FIG>, weft strand <NUM>-<NUM> forms a number of parallel weft segments <NUM> in fabric <NUM>. Weft segments <NUM> may have different widths W. For example, weft segments <NUM> in region <NUM> may have a greater width than weft segments <NUM> in region <NUM>. In this example, the spacing S between adjacent segments <NUM> is uniform in fabric <NUM>. However, if desired, segments <NUM> may have a non-uniform spacing.

In the example of <FIG>, weft strand <NUM>-<NUM> has segments of variable width and has different patterns in different regions of fabric <NUM>. In the example of <FIG>, weft strand <NUM>-<NUM> has segments <NUM> with variable width and a variable spacing S between neighboring segments. For example, one pair of segments <NUM> may have be spaced apart by a distance S1, whereas another pair of segments <NUM> may be spaced apart by a distance S2 that is less than S1.

Claim 1:
A warp knit fabric (<NUM>), comprising:
a plurality of warp strands (<NUM>-<NUM>) intertwined with one another, wherein the warp strands (<NUM>-<NUM>) include a first warp strand that forms a first edge of the fabric (<NUM>) and a second warp strand that forms a second edge of the fabric (<NUM>) and wherein a width (W) of the warp knit fabric (<NUM>) extends from the first edge to the second edge;
a weft insertion strand (<NUM>-<NUM>, <NUM>-<NUM>', <NUM>-<NUM>") inserted into the warp knit fabric (<NUM>) across the warp strands (<NUM>-<NUM>) between the first and second edges of the fabric (<NUM>), wherein the weft insertion strand (<NUM>-<NUM>, <NUM>-<NUM>', <NUM>-<NUM>") extends across less than all of the warp strands (<NUM>-<NUM>), wherein the weft insertion strand (<NUM>-<NUM>, <NUM>-<NUM>', <NUM>-<NUM>") comprises a conductive strand that conveys electrical signals, and characterized by
a warp insertion strand (<NUM>-<NUM>) inserted into the warp knit fabric (<NUM>) along the length (L) of the warp knit fabric (<NUM>).