The present invention relates to a fabric clamping frame for embroidery machines and to an embroidery machine comprising said frame. The invention also relates to a method for sewing labels with said embroidery machine.

An embroidery machine typically comprises a fixed sewing head, provided with one or more needles crossed by a thread and movable with reciprocating motion in a substantially vertical direction, i.e., substantially at right angles to a resting surface for the fabric to be embroidered. Furthermore, the embroidery machine typically also comprises a fabric clamping frame, which is detachably supported by a mechanism with carriages that can move in two respective perpendicular directions X and Y, which define a geometric plane X-Y substantially at right angles to the direction of motion of the sewing needle. Said geometric plane coincides with, or is substantially parallel to, the resting surface for the fabric to be embroidered. In this manner, by combining the movements of the carriages on the plane X-Y, the fabric held by the clamping frame can be moved parallel to said resting surface according to a plurality of positions so that the needle can form a sewing line according to a plurality of predefined patterns, obtained on the basis of at least one embroidery program stored in the control system integrated in or associated with the embroidery machine.

One drawback of known embroidery machines is encountered when they are used to fix a label, also known as patch, on a fabric. To perform such fixing, the sewing line provided by the embroidery machine substantially follows the perimeter of the label, so that the entire perimeter of the label is sewn onto the fabric.

With an embroidery program for sewing according to a pattern which substantially corresponds to the external shape of the label to be applied, it is complicated for an operator to correctly orient and retain the label with respect to the sewing head so that the label is correctly positioned and oriented on the fabric and so that the sewing line generated by means of the embroidery program for that label is correctly aligned along the entire edge of the label. An incorrect alignment can lead to uneven edge work on the label, as well as visible defects on the sewing line. The operator must also hold the label steady with his hand during at least part of the sewing on the fabric.

A further drawback arises when multiple labels, even with different shapes, have to be fixed to the fabric. In this case the operator may also have difficulty in positioning correctly the labels in relation to each other on the same fabric.

An embroidery machine is known from US Patent 5,454,337 which has a clamping plate having two cutouts with dimensions smaller than the respective labels to be sewn, which therefore must be oriented approximatively by the operator on the fabric before clamping the fabric and the labels with the plate.

The aim of the present invention is to provide a fabric clamping frame and a corresponding embroidery machine, as well as a corresponding method, which are capable of improving the background art in one or more of the aspects mentioned above.

Within the scope of this aim, an object of the invention is to be able to perform correct sewing along the perimeter of a label to be fixed to a fabric, allowing the correct positioning and orientation of the label on the fabric and reducing the risks of injury for the user.

A further object of the invention is to facilitate the precise application of a plurality of labels, even mutually different ones, to a same fabric or to different parts of a same item of clothing.

Another object of the invention is to devise a fabric clamping frame and a corresponding embroidery machine, as well as a corresponding method, for applying labels which can be used at the industrial level, i.e., for mass production of fabrics or items of clothing with sewn-on labels of the patch type.

Furthermore, an object of the present invention is to overcome the drawbacks of the background art in a manner that is alternative to any existing solutions.

Not the least object of the invention is to provide a fabric clamping frame and a corresponding embroidery machine, as well as a corresponding method, which are highly reliable, relatively easy to provide and have competitive costs.

This aim and these and other objects which will become more apparent hereinafter are achieved by a fabric clamping frame for embroidery machines according to claim 1 , optionally provided with one or more of the characteristics of the dependent claims.

The aim and the objects of the invention are also achieved by an embroidery machine according to claim 9 and by a method for sewing labels according to claim 10, optionally provided with one or more of the characteristics of the dependent claims.

Further characteristics and advantages of the invention will become more apparent from the description of a preferred but not exclusive embodiment of the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a view of a detail of an embroidery machine according to the invention, with the clamping frame raised in order to receive the fabric on which labels are to be applied;

Figure 2 corresponds to Figure 1 but with a cutout plate of the clamping frame and a border of said frame completely lowered in the position for clamping the fabric, i.e., for fixing the fabric to the clamping frame by friction;

Figure 3 corresponds to the preceding figure during the insertion of a first label in the cutout plate; Figure 4 corresponds to the preceding figure after the insertion of the first label;

Figure 5 is a view of the sewing of the label of the preceding figure along its perimeter;

Figure 6 is a view of the embroidery machine of Figure 1 when a second label is inserted in the border;

Figure 7 is a view of the beginning of the sewing of the label of the preceding figure;

Figure 8 is a view of the end of the sewing of the label of the preceding figure.

With reference to the cited figures, a fabric clamping frame for embroidery machines according to the invention, generally designated by the reference numeral 1, comprises a template 2, 3 for sewing labels, which is movable transversely with respect to a surface P for resting a fabric 4. The template 2, 3 is movable transversely with respect to the resting surface P between a raised position for insertion/removal of the fabric 4 from the embroidery machine and a lowered position for clamping the fabric 4 on the resting surface P, i.e. for pressing the fabric 4 against the resting surface P.

The clamping frame 1 is mounted, preferably in a detachable manner, on movement means of an embroidery machine 5, which is shown only partially in the figures. The movement means can comprise an arm 52 of a mechanism (per se known) with carriages that can move in two respective mutually perpendicular directions X and Y, which define a geometric plane X-Y substantially at right angles to the direction of the motion of the sewing needle 53 of the sewing head 51 of the embroidery machine 5. Said geometric plane X-Y coincides with, or is substantially parallel to, the resting surface P for the fabric 4.

The movement means respond to instructions of at least one embroidering program stored in a control system integrated in or associated with the embroidery machine 5. In this manner, by combining the movements of the carriages on the plane X-Y based on the instructions of the embroidering program, the fabric 4 guided by the clamping frame 1 can be moved parallel to the plane X-Y in a plurality of directions so that the needle 53 can provide a sewing line on the fabric according to one or more predefined patterns defined in the embroidery program.

In the preferred embodiment, shown in the figures, the resting surface P can be a smooth sliding surface for the fabric 4, such that the fabric 4 remains integral by friction only to the clamping frame 1 when said frame is in the lowered position on the surface P. Therefore, the pressure applied by the clamping frame 1 on the resting surface P is such as to allow in any case the sliding of the fabric 4 on the surface P, the fabric continuing to be retained in a direction at right angles to the surface P so as not to rotate and not to slide with respect to the clamping frame 1.

The resting surface P in this case can be covered by a Teflon layer or film, in order to allow effective sliding of the fabric 4 entrained by the clamping frame 1 during sewing. In order to create the friction necessary to keep the fabric 4 integral with the clamping frame 1 during sewing, the lower face of the clamping frame 1 (in contact with the fabric 4 during use) can advantageously comprise a layer, or some regions, made of rubber, optionally knurled rubber.

In an alternative embodiment, not shown, the resting surface is a counterpressure surface which is connected to the clamping frame 1 so as to move integrally with it on a plane X-Y and on which the fabric 4 is fixed by friction by the clamping frame 1 when said frame 1 is in the lowered position.

The template of the clamping frame 1 is composed essentially of a cutout plate 2 and preferably also of a border 3 adapted to surround at least partially the cutout plate 2. The cutout plate 2 and/or the border 3 can optionally comprise on their lower face the layer, or the regions, made of rubber in order to create the friction with the fabric 4, as explained previously.

The cutout plate 2 preferably has a rectangular outer shape and comprises one or more cutouts 21-22 having a shape that corresponds to a respective label to be applied by sewing to the fabric 4, so that said label can be laterally retained within the respective cutout by form-fit coupling, particularly during the sewing of the label on the fabric 4.

In particular, the internal rim 22a of at least one first cutout 22 of the plate 2 is adapted to completely surround a first respective label 20 during sewing, since the shape of said internal rim 22a is substantially the same as the shape of the perimetric rim 20a of the first label 20.

In the embodiment shown, the cutout plate 2 can also comprise a second cutout 21, the internal rim 21a of which corresponds to that of another, respective label (not shown) having the same shape as the cutout 21.

The border 3 is adapted to surround at least partially the cutout plate 2, so as to leave a gap 23 between the internal rim 31 of the border 3 and the outer rim 25 of the cutout plate 2, said rims being preferably complementary in shape so as to form a gap 23 of substantially constant width, for example a substantially rectangular slit, as shown in the figures. The width of the gap 23 around the cutout plate 2 is in any case such as to allow at least one needle 53 of the embroidery machine 5 to pass, in order to be able to sew the fabric 4 exposed along the gap 23.

The border 3 can be, for example, a plate with a single cutout having a closed shape, defined by the internal rim 31, for example a substantially rectangular cutout as in the figures.

The internal rim 31 of the border 3 optionally defines a lateral containment wall for the outer rim of a corresponding second label 30 to be fixed to the fabric 4 by means of a corresponding perimetric sewing line 34, which is preferably closed.

According to the invention, the clamping frame 1 comprises at least one device 6 for pressing at least one label 20 to be sewn on the fabric 4.

The pressing device 6 is mounted on the clamping frame 1 so as to be able to move integrally therewith. In particular, the pressing device 6 can be mounted on the border 3 so as to be laterally adjacent to the cutout 31 (i.e., laterally adjacent to the cutout plate 2). In an alternative embodiment (not shown), the pressing device 6 can be instead fixed on the cutout plate 2, for example if the border 3 is not provided in the clamping frame 1. In both cases, the border 3 or the cutout plate 2, respectively, have a convenient tab adapted to provide an additional surface on which the pressing device 6 can be fixed.

The pressing device 6 comprises a pressure plate 60, which is movable with respect to the clamping frame 1 substantially parallel to the resting surface P, between a first position, in which the pressure plate is accommodated in a respective cutout 22 of the cutout plate 2, and a second position, in which the same cutout 22 is not obstructed by the pressure plate 60.

In the embodiment shown, the pressure plate 60 can move at least in a direction that is substantially parallel to the resting surface P. In an alternative embodiment, not shown, the pressure plate 60 can rotate about an axis which is eccentric with respect to the pressure plate and at right angles to the resting surface P.

The pressure plate 60 can have a shape that is substantially similar to that of a respective cutout 22, as in the example of the figures, but in any case it has a surface extent that is smaller than the extent delimited by said cutout 22, so as to leave a gap between the outer rim of the pressure plate 60 and the internal rim 22a of the respective cutout, along which the sewing line 24 is to be provided.

The pressure plate 60 is mounted on a rectilinear slide 61 that can slide in a linear manner in a direction that is substantially parallel to the resting surface P, i.e., parallel to the upper surface of the border 3 and/or of the cutout plate 2, and that preferably passes over the cutouts 31 and 22. The slide 61 is preferably guided in translation inside a block 66 which is fixed to the border 3, for example by providing inside the block 66 a fixed guiding tooth that passes through a longitudinal rectilinear slit 65 of the slide 61.

The pressure plate 60 may comprise at least one lifting rod 63, advantageously provided with a respective knob 62 that can be gripped by the user in order to lift or lower the pressure plate 60 with respect to the resting surface P. The lifting rod 63 passes slidingly through a respective guiding hole located at the end of the slide 61 that is closest to the cutout plate 2 and allows the pressure plate 60 to move in a direction substantially perpendicular to the sliding direction of the slide 61, i.e., at right angles to the cutout 22 of the cutout plate 2, i.e., to the resting surface P for the fabric 4.

Optionally, the pressure plate 60 can also comprise a rotationpreventing pin 64 which is spaced from the lifting rod 63 and also passes through the rectilinear slide 61 at another guiding hole, so that the two elements 63 and 64 together prevent the rotation of the pressure plate 60 with respect to the slide 61.

Optionally, a spring can abut between the slide 61 and the pressure plate 60 or between the slide 61 and the knob 62 in an elastically loaded configuration so as to apply a force that tends to move the pressure plate 60 closer toward the resting surface P for the fabric 4, in order to retain the label 20 in the direction at right angles to the resting surface P within the respective cutout 22. As an alternative, said spring can be avoided if the weight of the pressure plate 60 alone is sufficient to perform this function of retaining the label 20 in the direction at right angles to the resting surface P.

By virtue of the pressing device 6 it is possible to increase the safety of the user, since the label 20 to be sewn on the fabric 4 can be held still also in a direction at right angles to the resting surface P during its sewing on the fabric 4. This is particularly advantageous in those cases in which the label tends to rotate about the axis of the needle 53 during its sewing, due to its surface extent, to its material and/or the shape of the label and of the corresponding cutout, for example if said shape does not have (a sufficient number of) corners adapted to avoid said rotation of the label inside the cutout during its sewing.

The cutout plate 2 and the border 3 can advantageously move with respect to each other in a transverse direction and preferably at right angles to the resting surface P for the fabric 4, i.e., to the plane X-Y.

In particular, the cutout plate 2 and the border 3 are associated with a support 54 which is fixed to the movement means 52 of the clamping frame 1.

The support 54 comprises a first linear guide 55 for a first slider 26 to which the cutout plate 2 is fixed by means, for example, of a bracket 27 which protrudes in a cantilever manner from the first slider 26. The first linear guide 55 is directed transversely to the plane X-Y for the movement of said support 54, i.e., to the resting surface P, and more preferably it is at right angles to the plane X-Y and/or to the surface P, as in the embodiment shown in the drawings, so as to guide the linear translation of the cutout plate 2 along said direction at right angles to the plane X-Y and/or the surface P.

Advantageously, a U-shaped connecting shaft 57 can be provided so as to straddle the gap 23 between the bracket 27 and the cutout plate 2. The shaft 57 can rotate through approximately 180° about an axis that is substantially parallel to the resting surface P and passes at the ends of the U- shape. The shaft 57 can rotate on command with respect to the bracket 27 and the cutout plate 2 about said axis so as to expose alternatively the open side of the U-shape to the left and to the right of said axis during the sewing of the line 34 in order to accommodate the needle 53 arriving from the left and from the right respectively, and thus allowing sewing also in the region along the gap 23 between the bracket 27 and the cutout plate 2.

The support 54 can also comprise a second linear guide 56 for a second slider 36, said second guide 56 being parallel to the first guide 55. The border 3 is fixed to the second slider 36 by means of, for example, another bracket 37 which protrudes in a cantilever manner from the second slider 36. In this manner, the linear translation of the border 3 along a direction that is transverse, and more preferably perpendicular, to the plane X-Y and/or the surface P can be guided.

The lifting mechanism can comprise a lever system (not shown) adapted to move selectively the sliders 26 and 36. Said lever system can have manual or automatic actuation.

The stored embroidering program of the embroidery machine 5 comprises the patterns of the sewing lines (24, 34) and instructions for moving the arm 52 so as to perform, in sequence, each sewing line in response to a respective start command by the user which brings the clamping frame 1 to a known “zero” starting position with respect to the sewing needle 53.

Since the correspondence between the pattern of the sewing line (for example 24) and the shape of the label to be applied (for example 20) is predefined and unequivocal, and since the shape of the cutouts 21, 22, 31 or of the gap 23 is predefined, said "zero" positioning is programmed so as to place below the needle 53 a region within the cutouts 21, 22, 31 or the gap 23 and near to the rims 21a or 22a or 31, respectively, according to the respective pattern of the sewing line to be provided. The user will have to arrange the label beforehand within the respective space of the template and start the corresponding embroidering program.

The operation of the invention is evident from the structural description given above.

In the illustrated embodiment, the method for sewing the labels 20 and 30 on the fabric 4 by means of the embroidery machine 5 provides for initially lifting the clamping frame 1 in order to allow the user to insert the fabric 4 between the frame 1 and the resting surface P.

The clamping frame 1 is then lowered onto the resting surface P in order to retain the fabric 4 in a direction at right angles to the resting surface P and integrally with said frame 1. In the case shown, said retention is obtained by friction between the frame 1 and the fabric 4, which renders the fabric 4 integral with the frame 1 but allows the fabric 4 to slide on the resting surface P.

During the lowering of the clamping frame 1 onto the resting surface P, the cutout plate 2 and the border 3 can be lowered simultaneously, as in Figure 2. As an alternative, it is possible to lower the border 3 first, actuating therefore the lowering of the slide 36 alone, and then the cutout plate 2

This step can be repeated several times in order to allow the user to arrange the fabric 4 in the best manner with respect to the sewing head 51 and to the region where he/she wishes to apply the label.

The independent mobility of the cutout plate 2 and of the border 3 in the direction that is transverse to the plane X-Y and/or to the resting surface P is useful for loading into the template labels of different types that have a corresponding shape only in the inner rims of only one of the cutout plate 2 and the border 3.

For example, by lowering the border 3 first, as shown in Figure 6, it is possible to insert the second label 30, bringing it into abutment against the internal rim 31 of the border 3, and then start the embroidering program in order to provide the second sewing line 34 first.

The slide 61 is in the retracted position, so as not to prevent the relative movement of the cutout plate 2 and of the border 3 and so as not to obstruct the cutout 22.

Upon the lowering of the cutout plate 2, the user can insert the first label 20 in the corresponding cutout 22 of the cutout plate 2, making substantially the entire label 20 come in contact with the portion of the fabric 4 that is exposed in the cutout 22 (Figure 4). Given that their perimetric shapes are identical, after said insertion the first label 20 is retained laterally by the internal rim 22a of the cutout by form-fit coupling, so as not to move along the fabric 4.

Optionally, based on the template and the number of labels of different shape to be applied, the user can insert in the optional second cutout 21 the label having the corresponding shape.

At this point, the user grips the knob 62 and drags the pressure plate 60 over the cutout 22, letting the pressure plate 60 fall so that it rests on top of the label 20 (Figure 5). A gap is thus left along the entire perimeter between the pressure plate 60 and the cutout 22, and the perimeter of the label 20 remains exposed at such gap.

Then the user starts the embroidering program in order to apply the first sewing line 24 along the peripheral region of the label 20 resting on the fabric 4 through the cutout plate 2. The sewing line 24 is preferably closed. The embroidery machine 5, by virtue of the movement means 52, brings the frame 1 to the zero position to sew the first line 24 and sewing is started, performed by the needle 53 and obtained by moving conveniently the fabric 4 and, integrally, the label 20 by virtue of the movements of the frame 1 that are provided in the embroidering program.

Once the perimetric sewing of the first label 20 has been completed, the user lifts and drags the pressure plate 60 so as to return the slide 61 to the retracted position and lifts the clamping frame 1 in order to move the fabric 4 to another point on which the optional second label 30 is to be applied or in order to insert a new fabric on which said second label 30 is to be applied. Then, only the border 3 is lowered so that the border 3 retains the fabric in a direction at right angles to the resting surface and the second label 30 is inserted by the user, placing it in abutment against the internal rim 31 of the border 3. The cutout plate 2 can be then lowered onto the fabric and the user starts the embroidering program of the second sewing line 34. The embroidery machine 5, by virtue of the movement means 52, brings the frame 1 to the zero position to sew the second line 34 and sewing is started, performed by the needle 53 and obtained by moving conveniently the fabric 4 and, integrally, the second label 30 by virtue of the movements of the frame 1 provided in the embroidering program. In the embodiment shown, the preset correspondence between the dimension of the template and the dimensions of the stored sewing line makes the needle provide the second sewing line 34 along the entire gap 23 between the border 3 and the cutout plate 2.

In practice it has been found that the invention achieves the intended aim and objects.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may furthermore be replaced with other technically equivalent elements.

In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art. For example, the cutout plate 2 and the border 3 can be made of steel, Plexiglas or a polymeric material.

The disclosures in Italian Patent Application No. 102022000018630 from which this application claims priority are incorporated herein by reference.

Where the features and the techniques mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.