Adjustable presser foot for a sewing machine for inserting an electronic tag into a sewn seam

Abstract

The invention relates to an adjustable presser foot (6) for a sewing machine having at least one needle moving vertically back and forth in order to sew a seam on a textile piece while securing an electronic tag (1) in the form of a strip to the textile piece by means of stitches. The presser foot (6) comprises a sole, guide means for guiding the electronic tag (1) substantially parallel to the feed direction of the textile piece and adjustment means for adjustably positioning the guide means laterally relative to the feed direction of the textile piece.

Description

DOMAINE DE L'INVENTION

[0001] The present invention relates to the field of textile manufacturing, such as clothing, and more particularly to the electronic identification labeling of textile items. The invention specifically relates to a presser foot for a sewing machine for creating a garment seam while simultaneously attaching an electronic identification label to the garment with stitches. ARRIERE PLAN TECHNOLOGIQUE DE L'INVENTION

[0002] Electronic identification tags used in this field are referred to as "RFID tags" (from the initials of the English expression "Radio-Frequency Identification"). Such tags comprise an electronic identification chip with radio-frequency transmission and reception capabilities coupled with an antenna. In addition to transmission and identification functions, the electronic chip of an electronic tag as discussed in this document can also be configured to perform functions other than identification, such as measurement functions (e.g., temperature, humidity, pressure), or even luminescence functions.

[0003] According to a conventional approach, the antenna is formed by conductive tracks arranged on a plastic or paper substrate. The chip is glued to the substrate so that its connection pads make contact with the conductive tracks forming the antenna. The substrate is generally rectangular in shape, with dimensions several centimeters long and wide to accommodate the antenna's required size and to facilitate handling of the label.

[0004] The functional assembly consisting of the chip and its substrate is generally referred to as an "inlay" in the relevant English-language literature. Such inlays are typically manufactured collectively on a substrate strip and are available in roll form. To create an electronic identification tag from an inlay, the inlay is usually packaged in a protective casing, for example, made of plastic, as documented in US patent 8212676. The dimensions of the resulting tag are, in the aforementioned document, relatively large: a height / thickness of 5 mm, a length of 150 mm, and a width of 22 mm.

[0005] To facilitate the integration of identification functions into textile products, efforts have been made to give an electronic label a wire form factor. Documents US6329917, WO2016038342, WO2011161336, GB2472025, GB2472026, US20110147462, WO2008080245, and WO2019175509 describe textile threads incorporating antennas and electronic chips at intervals along their length.

[0006] The term "textile yarn," or simply "yarn," refers to elements that can be woven or incorporated into a textile product. These yarns possess conventional tensile strength, flexibility, and shape characteristics for weaving, allowing them to be handled by standard equipment available in the garment industry. Such "textile yarns" incorporating antennas and RFID chips can be integrated into textile products during manufacturing or attached to the product after it has been made.

[0007] Document WO 2021 / 089939 aims to provide an electronic identification tag consisting of a ribbon containing a wired electronic device. Tag 1 of figures 1a et 1b The label 1 is rectangular (and more generally trapezoidal) in shape, several centimeters long, typically between 3 cm and 20 cm. The corners of the label 1 may be rounded. The length of the label 1 is sufficient to accommodate an antenna wire 3b of an RFID device, or RFID wire 3. Advantageously, this antenna wire 3b runs straight along the length of the label 1. It can extend from one end of the label 1 to the other, as shown in Figure 1a, or approach its ends without reaching them, as shown in Figure 1b. The antenna wire 3b can also be arranged diagonally across the label, making it more compact.It can also be anticipated that the antenna wire 3b will not be perfectly straight, but will have at least one curve in the plane of the label, so as to accommodate any elastic deformation of the label. The width of the label 1 is generally smaller than its length, typically less than one centimeter, and typically between 1 mm and 8 mm. Its thickness can range from 0.1 mm to 2 mm.

[0008] The label 1 in the examples in Figures 1a and 1b is specifically composed of two portions of textile ribbon 2a, 2b joined and sealed to each other along their main faces. Sandwiched between these two faces is a segment of an RFID wire 3 comprising an electronic chip 3a and antenna wire 3b. The ribbon portions, and therefore the label 1, have sufficient flexibility so as not to alter the flexibility of the textile piece into which they are intended to be integrated. Similarly, they may have sufficient elasticity to conform to the elasticity of this textile piece.They can therefore exhibit an elongation capacity ranging from 0% (and thus be able to be integrated into jeans or the thick canvas of a work suit, i.e., textiles made of fabrics that are not prone to stretching) to 100% (and be able to be integrated into textiles made of elastic fibers), and preferably in the range of 5 to 20% (for integration into classic knit textiles such as T-shirts, etc.). For this reason of integration into a textile, the use of textile ribbons to create the label 1 is a preferred method of implementation, although it is not the only possible method. The ribbon sections 2a, 2b can therefore be made of, or include, a wide variety of materials, chosen according to the sealing technique used or the nature of the textile into which the label is intended to be integrated.

[0009] As for the RFID wire segment 3 of the tag 1, it always comprises at least one electronic identification chip 3a with radio frequency transmit / receive functions, electrically coupled to at least one conductive wire 3b forming the transmit / receive "electric" antenna. Such an RFID wire segment 3 can be implemented in various ways, as summarized in WO2021 / 089939.

[0010] As also described in WO2021 / 089939, a segment of RFID wire 3 is perfectly suited for integration in all known ways, sandwiched between two portions of ribbon, and to form the electronic identification tag 1 illustrated on the [ Fig.1c ].

[0011] On this electronic identification label 1 of the [ Fig.1c [ ], the RFID thread segment 3 is positioned along and parallel to an edge of the label and is centered across its width. The sealing of the ribbon sections is illustrated by sealing points 4 (shown as dotted lines) arranged on either side of a central line 5 comprising the RFID thread segment 3 (not visible in this figure). This creates "inert" surfaces on either side of this central line 5 on the label 1, allowing the electronic label 1 to be attached to a textile piece without affecting the operation of the RFID textile thread 3.More specifically, a minimum distance d must be maintained between the RFID thread segment and an edge of the electronic tag 1. This distance must allow for a sufficiently wide inert strip to accommodate stitching points on one and / or the other side of the RFID textile thread 3, enabling the electronic tag 1 to be attached to a textile piece via a finishing seam. This minimum distance d could be, for example, 0.5 to 4 mm. Such a finishing seam is a seam whose primary function is to process the textile piece into a finished product.

[0012] The present invention provides for taking advantage of this garment seam to integrate the electronic label 1 as illustrated in the [ Fig.2 ], so that the electronic wire identification device is positioned within this garment seam, integrates easily, and is effectively protected. The electronic tag 1 can be integrated under any of the garment seams, for example, the sides or shoulders, which are substantially straight and illustrated with dotted lines on the T-shirt of the [ Fig.2 ].

[0013] The present invention also provides that this garment stitch, which secures the electronic label 1 to the textile piece, is advantageously formed of overlock stitches, and the electronic wire identification device is positioned more particularly under the upper looper thread of the overlock stitches. These stitches constitute a garment-making step for finishing the edge of a textile piece. This step is typically performed by an overlock machine, which is a piece of textile manufacturing equipment that simultaneously assembles, overlocks edges, and trims excess fabric. In particular, it allows pieces of fabric to be joined by overlocking their edges to create a finished product.An overlock machine is generally equipped with multiple needles supplied by multiple threads (at least two, sometimes five or more) from spools, allowing it to simultaneously sew and overlock the fabric piece(s) being joined. It may also be equipped with at least one blade for trimming excess fabric.

[0014] We have thus represented on the [ Fig.3 ] a piece of a textile part A to which an electronic label 1 has been attached here by overlock stitches.

[0015] We observe more particularly on this [ Fig.3 that the electronic tag 1 can be attached here to the textile piece A, firstly by means of a first straight stitch C1, formed by a first needle of the overlock machine, and substantially parallel to the RFID textile thread, and secondly by loops C3, formed by the upper looper thread. Other stitches, formed by other needles, can naturally be used, for example a second straight stitch C2 (formed by a second needle of the overlock machine) visible on the [ Fig.3 parallel to the first straight seam C1, the set of these straight stitches and loops forming the overlock stitches.

[0016] To secure the electronic label 1 and produce the textile piece shown on the [ Fig.2 Alternatively, the electronic label 1 can be manually positioned on the part beforehand, and the assembly can then be slid under a conventional presser foot on the overlock machine. However, this positioning step can be laborious for an operator, and inaccurate positioning can lead to damage to the electronic wire identification device integrated into the electronic label 1 by piercing the wire identification device, thus rendering it inoperative.

[0017] This is also the case when the electronic tag is attached to the textile using a conventional presser foot, such as those described in documents US2653559, US4024824, or US4703706, which guides a ribbon or wire element. This guidance does not provide sufficient precision for positioning an electronic tag. OBJET DE L'INVENTION

[0018] The present invention aims to provide a specific tool for securing an electronic tag in the form of a ribbon within a garment seam by attaching it with stitches to a piece of fabric without damaging a wired electronic identification device embedded in the ribbon. More particularly, the invention aims to provide a specific presser foot for sewing machines to integrate an electronic tag into a garment seam in a precise, repeatable, reliable, and robust manner. The presser foot allows for positioning and guiding the electronic tag during the sewing operation to ensure that a functional tag is integrated into the seam. BREVE DESCRIPTION DE L'INVENTION

[0019] To achieve at least some of these objectives, the object of the invention proposes an adjustable presser foot for a sewing machine having at least one vertical reciprocating needle for performing garment sewing on a textile piece while attaching a ribbon-shaped electronic tag to the textile piece with stitches, the presser foot possibly comprising: a sole to be pressed against the textile piece to perform the sewing, the sole having a front edge and a heel portion extending laterally in a feeding direction of the textile piece; the sole having a laterally open recess between the front edge and the heel portion defining a drop space for at least one needle through which at least one needle enters the textile piece to perform the sewing; a guiding means for guiding the electronic label through the recess so as to position a part of the electronic label therein such that a longitudinal axis of the electronic label in the form of a ribbon is substantially parallel to the feeding direction of the textile piece, adjustment means for positioning the guiding means laterally relative to the feeding direction of the textile piece.

[0020] Advantageously, the presser foot according to the invention allows an electronic label in the form of a ribbon to be inserted into a seam of a garment by pre-positioning it in the seam in a selected position and orientation relative to the garment and the leading edge of the sole to secure the electronic label to the garment precisely, reproducibly, and robustly. A wired electronic identification device comprising a chip electrically coupled to at least one antenna wire and integrated into the ribbon is advantageously positioned relative to the stitching points so as to integrate the functional electronic label into the seam.

[0021] According to other advantageous and non-limiting features of the invention, taken alone or in any technically feasible combination: the guiding means may include a guide tunnel inclined towards the sole and extending substantially parallel to the feeding direction of the textile piece, the guide tunnel having a first inlet end through which the electronic ribbon tag is engaged in the guide tunnel in a sliding manner and a second outlet end through which the electronic ribbon tag is guided to the recess in the sole to be positioned in the drop space of at least one needle so as to be drawn into the sewing seam;The means for adjusting the guide tunnel may include an angled rod with a first rod portion connected to the guide tunnel and a second rod portion capable of sliding laterally relative to the direction of feeding the textile part in a hollow cylinder arranged on the heel portion of the sole, the first rod portion and the second rod portion of the angled rod being connected substantially perpendicularly to each other by an elbow; the second rod portion may be locked laterally in the hollow cylinder by one or more clamping screws; the guide tunnel may be tilted angularly by a pivoting effect of the second part of the angled rod in the hollow cylinder; the sole may further include a V-shaped notch under the front edge of the sole, the opening of the V of which guides the electronic label in the direction of feeding the textile part;A retaining step may be arranged on the front edge of the sole and may be in the form of a projecting edge arranged orthogonally upwards relative to the recess to retain the label at the level of the recess; the presser foot may include a mounting shank for removably mounting it on the lower end of a pressure bar of the sewing machine, the shank having an adjusting screw for adjusting the lateral position of the drop space of at least one needle of the presser foot with openings of a feed plate of the textile workpiece in the direction of feeding the textile workpiece by the sewing machine.

[0022] Advantageously, the presser foot according to the invention can be a presser foot for an overlock machine and the stitches can be overlock stitches.

[0023] As discussed previously, the present invention also covers the use of a presser foot according to the invention for inserting an electronic wire identification device integrated into a ribbon-shaped electronic label in a seam of a textile garment. BREVE DESCRIPTION DES FIGURES

[0024] Other features and advantages of the invention will become apparent from the detailed description of the invention which follows with reference to the accompanying figures in which: [ Fig.1a ] ] Fig.1b ] ] Fig.1c ] THE figures 1a, 1b, 1c represent methods of implementing a ribbon-shaped electronic tag comprising a wired electronic device; [ Fig.2 ] There [ Fig.2 ] represents a piece of textile assembled by a garment seam with an electronic tag attached to the garment seam; Fig.3 ] There [ Fig.3 ] represents a garment seam on a piece of textile with an electronic label attached to the textile piece with overlock stitches; Fig.4a ] ] Fig.4b ] ] Fig.4c ] ] Fig.4d ] ] Fig.4e ] ] Fig.4f ] THE figures 4a, 4b , 4c, 4d , 4e et 4f represent different views of a presser foot according to the invention for an overlock machine; [ Fig.5 ] There [ Fig.5 ] represents the presser foot according to the invention for an overlock machine installed on an overlock machine; [ Fig.6a ] ] Fig.6b ] THE figures 6a , 6b represent another example of a means of guiding a crowbar according to the invention. DESCRIPTION DETAILLEE DE L'INVENTION

[0025] THE figures 1a, 1b, 1c, 2 And 3have already been discussed in the technological background of the invention to illustrate the problem of ensuring the preservation of the functionality of an electronic tag 1 integrated into a textile garment in a seam. The electronic tag 1 is formed from a ribbon-like material, comprising, for example, a wired electronic device sandwiched between two ribbon segments 2a, 2b. The electronic tag 1 has "inert" surfaces on either side of the central line 5 to allow the electronic tag 1 to be attached to the textile garment by stitching without affecting the operation of the RFID textile thread 3.

[0026] In the remainder of this description, the garment stitching will be described as being carried out by an overlock machine having at least one vertical reciprocating needle to perform the garment stitching on the textile piece while attaching the electronic label 1 to the textile piece with overlock stitches of the garment stitching as illustrated in the [ Fig.3 ].

[0027] However, garment sewing can also be performed by any type of sewing machine capable of other stitches, such as the straight stitch, coverstitch, and chain stitch, equipped with an adjustable presser foot possessing the distinctive technical characteristics described below compared to state-of-the-art presser feet. To create overlock stitches for garment sewing, an overlock machine is equipped with an adjustable presser foot (or presser foot) shown separately in the diagrams. figures 4a, 4b , 4c, 4d , 4e, 4f which is removablely mounted on the lower end of a serger pressure bar via a T-mount rod. The textile piece to be assembled is compressed between a feed plate (not shown) arranged on the serger frame and a sole 7 of the presser foot 6. During the sewing process, the textile piece is driven by mechanical feed teeth arranged in grooves in the feed plate and these feed teeth will guide the textile piece in a certain feeding direction.

[0028] At least one needle is attached to a needle bar by means of a screw. During operation, the needle bar moves back and forth vertically within openings in the feed plate to create the overlock stitch along the edge of the fabric. Knives may be included to trim excess fabric from the garment along the stitching.

[0029] The presser foot 6 therefore includes the sole 7, which is mechanically pressed against the fabric to perform the sewing. The sole 7 extends laterally in the direction of feed of the fabric. The sole 7 has a front edge 7a and a heel portion 7b separated from the front edge 7a by a laterally open recess 8. This recess 8 defines a drop space for at least one needle, through which the needle enters the fabric and then the openings in the feed plate to perform the overlock stitch before the fabric passes under the front edge 7a of the sole 7. The recess 8 is large enough to allow the label to pass through it, as will be explained later in this description.

[0030] The T-mount shank of the presser foot 6 has an adjustment screw to adjust the lateral position of the drop space of the presser foot 6 with the openings of the feed plate of the textile part in the direction of feed of the overlock machine.

[0031] According to the invention, a guiding means is present on the presser foot 6 to facilitate the positioning of the electronic ribbon label 1 to be integrated into the garment seam, and more specifically to position the electronic ribbon label 1 within the drop space so that a longitudinal axis of the electronic ribbon label 1 remains substantially parallel to the direction of feed of the textile during the garment seam. This guiding means also makes it possible to maintain the wired electronic device of the electronic label 1 at a certain distance from the needle(s) during the garment seam so that it is not damaged by the needle(s) during sewing and remains functional.

[0032] The guiding means comprises a guide tunnel 9, arranged on the sole 7 at the heel portion 7b, through which the electronic tag 1, in the form of a ribbon, is inserted to be directed towards the drop space. The guide tunnel 9 is inclined downwards towards the recess 8 in the sole 7 and extends substantially parallel to the direction of feed of the textile piece. The guide tunnel 9 has a first end, referred to as the inlet, through which the electronic tag 1 is slidably inserted, and a second end, the outlet, through which the electronic tag 1 is guided to the recess 8 in the sole 7 to be positioned in the drop space of the needle(s) so as to be drawn through the recess 8 into the overlock stitch during its construction.

[0033] As seen on the figures 4a à 4f The first end of the guide tunnel 9 has a funnel-shaped profile with an inlet width i and thickness ii significantly greater than the width and thickness of the electronic ribbon tag 1. The guide tunnel 9 then has a substantially straight guide section up to the second end, which has a width 1 and a thickness 11 preferably substantially close to the width and thickness of the electronic ribbon tag 1. For example and without any limitation, for an electronic tag 1 in the form of a ribbon 4mm wide, approximately 2mm thick, and 100mm long, the guide tunnel 9 may have a funnel-shaped inlet of width i 10.4mm, thickness ii 6.7mm and extend over a first section iii of 8mm, then extend over a straight section L of approximately 30mm, and have a second guide tunnel outlet end of width 1 4.7mm and thickness 11 2.3mm.Since the thickness ll of the straight section L of the guide tunnel 9 is substantially close to the thickness of the electronic ribbon label 1, the latter cannot twist when passing through the guide tunnel 9 and has a position and orientation selected in a reproducibly manner when arriving in the drop space.

[0034] In the case of a 6-point overlock presser foot, this includes guide fingers 10 in the form of two visible claws on the figures 4a , 4c And 4ewhich extend projecting from the heel portion 7b of the sole 7 towards the drop space of the needle(s) and which are substantially parallel to the direction of feeding of the textile piece. One of the guide fingers 10 is said to be internal 10a and the other guide finger is said to be external 10b with respect to their positioning in the opening of the recess 8. In a known manner, a lateral adjustment screw 12 of the guide fingers 10 with respect to the front edge 7a of the sole 7 is arranged on the heel portion 7b of the sole 7, as visible in the [ Fig.4c ] And 4f . This adjustment screw 12 allows in particular to align the guide fingers 10 with respect to the direction of feeding of the textile piece and the point of impact of at least one needle in the textile piece.

[0035] According to the invention, the presser foot 6 includes means for positioning the guide tunnel 9 laterally in an adjustable manner relative to the front edge 7a of the sole 7 so as to ensure that the electronic wire identification device of the electronic label 1 is kept at a certain distance from the needle(s) during the sewing process, but also so that the electronic label 1 is integrated into the sewing process here under the loops of the overlock stitches.

[0036] These means for adjusting the guide tunnel 9 include, in particular, an angled rod 14 visible on the figures 4b à 4d with a first stem section 14a connected to the guide tunnel 9 and a second stem section 14b, here circular in cross-section, capable of sliding laterally relative to the direction of feeding of the textile piece into a hollow cylinder 15 arranged on the heel portion 7b of the sole. The first stem section 14a and the second stem section 14b of the angled stem 14 are connected substantially perpendicularly to each other by an elbow 14c.

[0037] The second part of the rod 14b can be laterally locked in the hollow cylinder, here by a set of clamping screws 13 as visible on the [ Fig.4c ].

[0038] As illustrated on the [ Fig.4d When the second part of the rod 14b of the angled rod 14 is engaged in the hollow cylinder 15 and laterally locked by the clamping screw assembly 13, the guide tunnel 9 can still be tilted angularly by a pivoting effect of the second part of the rod 14b within the hollow cylinder. This tilting improves user comfort because, during garment sewing, the user can stop the machine, tilt the guide tunnel 9 to raise it, and thus have easier visual access to the drop zone.

[0039] The adjustment of the lateral positioning of the guide tunnel 9 in relation to the drop space and the feeding direction of the textile piece must be done prior to the start of the sewing operation so that, in the case of an overlock machine, the straight overlock stitches C1 and C2 remain sufficiently far from the wired electronic device, i.e. that the needles pierce the inert surfaces of the electronic label 1 and preferably that the entire width of the ribbon-shaped electronic label 1 is in particular under the loops C3 of the overlock stitches.

[0040] Optionally, a guide channel 11 may be formed under the front edge 7a of the sole 7 as visible on the [ Fig.4e ] which houses the electronic label 1 in the form of a ribbon when it passes under the front edge 7a of the sole 7. This channel 11 is here formed by a V-shaped notch whose V opening is narrow and guides the electronic label 1 in the direction of feeding the textile piece and more particularly under the loops of the overlock stitches.

[0041] Optionally, as seen on the figures 4b And 4d A retaining step 16 is arranged on the front edge of the sole. This retaining step 16 is in the form of a projecting edge arranged orthogonally towards the top of the sole relative to the recess and which may have a height of 1 to 2 mm. If, during the insertion of the electronic tag 1 into the guide tunnel 9, at least one pin is raised, this retaining step 16 will prevent the electronic tag 1 from sliding beyond the recess, and in particular over the front edge of the sole.

[0042] THE figures 6a , 6b represent another example of a guiding means that can be placed on a base to form a crowbar according to the invention. This means comprises an angled guiding tunnel 9, allowing the label to be delivered as close as possible to the recess. The guiding tunnel 9 has a funnel-shaped profile, and its second end, directed towards the recess, has substantially the dimensions of the electronic label. Advantageously, and as can be seen in the [ Fig.6a ], this second end is equipped with a through passage 9a, this through passage allowing a needle to be passed through during the sewing process.

[0043] To allow the guide tunnel 9 to be placed on a wide variety of existing presser feet, the guide means includes a flange 17. This piece has any shape suitable for being placed and secured to the heel portion 7b of the sole 7.

[0044] We also find on the guidance system figures 6a , 6b an angled rod 14 held to the guide tunnel 9 and to the flange 17 by clamping screws allowing the precise lateral and angular positioning of the tunnel, as previously described.

[0045] When installing the presser foot 6 according to the invention on the overlock machine, prior to integrating an electronic label 1 into a garment seam, several adjustments must be made: adjust the positioning of the presser foot 6 in relation to the openings of the feed plate, adjust the positioning of the serger knife(s) so that there is no friction with the guide tunnel 9 of the presser foot 6, adjust the tension of the overlock stitch threads so that the thickness of the electronic label 1 in the garment seam does not create a fold in the garment seam during its production, adjust the positioning of the guide fingers 10, adjust the positioning of the guide tunnel 9 so as to ensure the preservation of the functionality of the wired electronic devices integrated into the electronic labels 1 to be inserted into garment seams.

[0046] If during a visual inspection the straight stitches C1 and / or C2 of the overlock stitches are positioned on the inert areas of the ribbon, and this at a distance deemed too close to the wired electronic device inserted in the electronic ribbon label 1 so that its functionality may be compromised by the needle(s), the lateral position of the guide tunnel 10 must be adjusted by repositioning the second part of the stem 14b in the hollow cylinder 15 of the heel portion 7b of the sole 7.

[0047] Once these settings are made, it is possible to start an overlock stitch to join the edges of a piece of fabric. During the joining process, the stitching is paused while an electronic label 1 is inserted into the guide tunnel 9, and pushed until it is against the thread(s) coming out of the needle(s) as illustrated in the [ Fig.5]. Then the garment sewing with overlock stitches can restart: the electronic label 1 is automatically fed and inserted under the upper loops of the overlock stitches of the garment sewing of the textile piece.

[0048] It is possible to integrate one or more electronic labels into one or more sewing seams, to change the textile piece to be assembled, and this without having to readjust the presser foot.

[0049] The presser foot 6 according to the invention allows at least one electronic label 1 to be integrated into at least one seam of the making of a textile piece in a repeatable, reliable and robust manner from one textile piece to another.

[0050] The adjustable presser foot according to the invention could also be used to attach the electronic label 1, in the form of a ribbon, to a piece of fabric, for example, whose edges have been previously joined with overlock stitches during a first sewing operation. Thus, the electronic label 1 could be attached to the fabric by means of a second sewing operation. To do this, the fabric is positioned under the presser foot at the point where the electronic label 1 is to be attached. Then, the electronic label 1 is inserted into the guide tunnel 9 and, in the same manner as described above, is fed into a second sewing operation with overlock stitches, for example, under the upper loops.

[0051] The first and second sewing seams may or may not be overlapped.

[0052] The adjustable presser foot according to the invention, with its guiding means, could also be used for any type of sewing machine, so that the stitches made by one or more needles passing through the electronic label 1, such as for example straight stitches, cover stitches, chain stitches, pass through the electronic label 1 at the level of the inert surfaces as defined above.

Claims

1. Adjustable presser foot (6) for a sewing machine having at least one needle moving vertically back and forth to produce a sewn seam on a textile piece while securing an electronic tag (1) in the shape of a strip to said textile piece with stitches, said presser foot (6) comprising: - a sole (7) to be pressed against said textile piece to produce said sewn seam, said sole (7) having a front edge (7a) and a heel portion (7b) extending laterally to a feed direction of said textile piece; - said sole (7) having a laterally open recess (8) between said front edge (7a) and said heel portion (7b) defining a drop space for said at least one needle through which said at least one needle penetrates said textile piece to produce said sewn seam; characterized in that the presser foot (6) further comprises - guide means for guiding said electronic tag (1) through the recess (8) so as to position a portion of said electronic tag (1) therein such that a longitudinal axis of said strip-shaped electronic tag (1) is substantially parallel to said feed direction of said textile piece, - adjustment means for adjustably positioning said guide means laterally with respect to said feed direction of said textile piece.

2. Presser foot (6) according to claim 1, characterized in that said guide means comprises a guide tunnel (9) inclined towards said sole (7) and extending substantially parallel to said feed direction of said textile piece, said guide tunnel (9) having a first inlet end through which said strip-shaped electronic tag (1) is slidably engaged in said guide tunnel (9) and a second outlet end through which said strip-shaped electronic tag (1) is guided to said recess (8) of said sole (7) in order to be positioned in said drop space of said at least one needle so as to be fed into said sewn seam.

3. Presser foot (6) according to claim 2, characterized in that said means for adjusting said guide tunnel (9) comprise a curved rod (14) with a first rod part (14a) connected to the guide tunnel (9) and a second rod part (14b) which can slide laterally with respect to said feed direction of said textile piece in a hollow cylinder (15) arranged on said heel portion (7b) of said sole (7), said first rod part (14a) and said second rod part (14b) of said curved rod (14) being connected substantially perpendicularly to each other by a bend (14c).

4. Presser foot (6) according to claim 3, characterized in that said second rod part (14b) is laterally locked in said hollow cylinder (15) by one or more locking screws (13).

5. Presser foot (6) according to claim 3 or 4, characterized in that said guide tunnel (9) can be tilted angularly by means of a pivoting effect of said second rod part (14b) of said curved rod (14) in said hollow cylinder (15).

6. Presser foot (6) according to one of the preceding claims, characterized in that said sole (7) further comprises a guide channel (11) in the form of a V-shaped notch under said front edge (7a) of said sole (7), the V-shaped opening of which guides said electronic tag (1) in said feed direction of said textile piece.

7. Presser foot (6) according to one of the preceding claims, characterized in that a retaining step (16) is arranged on said front edge (7a) of said sole (7) and is in the form of a protruding rim arranged orthogonally upwards with respect to said recess (8).

8. Presser foot (6) according to any one of the preceding claims, characterized in that it comprises a mounting rod (T) for removably mounting it on a lower end of a presser bar of said sewing machine, said mounting rod (T) having an adjustment screw for adjusting the lateral position of said drop space of said at least one needle of said presser foot (6) with openings of a plate for feeding said textile piece in said feed direction of said sewing machine.

9. Presser foot (6) according to any one of the preceding claims, characterized in that it is a presser foot for a serger and that said stitches are overlock stitches.

10. Presser foot (6) according to one of claims 2 to 9, characterized in that the guide tunnel (9) comprises a through passage (9a) arranged at its end leading to the recess of the sole (7).

11. Presser foot (6) according to one of claims 2 or 6 to 10, characterized in that the guide tunnel (9) is joined to the heel portion of the sole (7) via a flange (17).

12. Use of a presser foot (6) according to one of the preceding claims for insertion of a wired electronic identification device integrated in a strip-shaped electronic tag (1) into a sewn seam of a textile piece.

Images