SEWING MACHINE FOR SEWING A POCKET ON FABRIC AND METHOD FOR SEWING A POCKET ON FABRIC.

The present patent application for industrial invention relates to a sewing machine for sewing a pocket on fabric and to a method for sewing a pocket on fabric.

In particular, the present invention relates to a sewing machine for sewing pockets on apparel items, such as for example pants, shirts, T-shirts and the like.

As it is known, a sewing machine is a mechanical or electromechanical equipment used to join fabric, cloth, leather materials or the like by means of a seam, passing one or more threads of cotton or other materials through a needle that alternately oscillates from up down or vice versa.

Different types of sewing machines are known in the prior art, each of them being able to perform one or more working steps or one or more types of seams or stitches.

US5454336 discloses a sewing machine for sewing a pocket on fabric. Said sewing machine comprises a bearing frame and a work surface supported by the bearing frame. A loading and folding station and a sewing station are disposed on the work surface.

In particular:

- a folding unit is disposed in the loading and folding station for loading and folding the pocket to be sewn on the fabric;

- a sewing unit is disposed in the sewing station for sewing the pocket on the fabric.

A mobile sewing template is disposed in the sewing unit for sewing the pocket on the fabric. More precisely, the sewing template is suitable for being disposed over the fabric and over the pocket in order to hold and sew the pocket on the fabric. In particular, the sewing template is provided with a U- shaped slot suitable for acting as guide for sewing the pocket on the fabric. Said sewing template is mounted on the work surface in such a way to make not only vertical and transverse travels relative to the longitudinal axis of the work surface, but also lateral translations towards the loading and folding station. In view of the above, the sewing template can take the fabric and the folded pocket that is positioned over the fabric from the folding unit and transport the pocket and the fabric to the sewing unit in order to sew the pocket on the fabric.

Accordingly, the method for sewing a pocket on fabric by means of the sewing machine disclosed in US5454336 provides for the following steps:

- loading the fabric on the work surface in the loading and folding station;

- loading the pocket to be sewn on a plate of the folding unit;

- folding the pocket on the plate of the folding unit by means of the folding unit;

- lowering the plate of the folding unit in such a way that the folded pocket is positioned over the fabric;

- moving the sewing template from the sewing station to the loading and folding station in order to take the fabric and the folded pocket that is positioned over the fabric;

- removing the plate of the folding unit from the folded pocket;

- moving the sewing template from the loading and folding station to the sewing station;

- sewing the pocket on the fabric;

- moving the sewing template from the sewing station to the loading and folding station in order to take a new pocket to be sewn.

It must be noted that, until sewing is not completed, the sewing template cannot be moved from the sewing station to the loading and folding station in order to take a new pocket to be sewn.

As a matter of fact, the sewing template must necessarily remain under the sewing unit until sewing is completed, before it can travel backwards towards the folding unit and take a new pocket to be sewn. It is manifest that such a solution inevitably implies a reduction of the number of pockets sewn in a given time interval.

In particular, the number of pockets sewn in a given time interval is inversely proportional to the time required to complete sewing.

DE19864688 and US4813362 disclose two sewing machines provided with a sewing template that is used for transporting a fabric and a pocket folded over the fabric between a loading and folding station and a sewing station. The sewing template remains in the sewing station for the time interval that is necessary for the sewing unit to sew the pocket to the fabric.

Otherwise said, also the sewing machines disclosed in DE19864688 and US4813362 are impaired by said drawback, which consists in the fact that the number of pockets sewn in a given time interval is inversely proportional to the time that is necessary for sewing.

The purpose of the present invention is to eliminate the drawbacks of the prior art by disclosing a sewing machine for sewing pockets on fabric, which is capable of reducing the manufacturing time and the sewing time of apparel items.

These purposes are achieved according to the invention with the characteristics of the independent claims 1 and 10.

Advantageous embodiments of the invention appear from the dependent claims.

The sewing machine of the invention used for sewing a pocket on fabric, comprises:

- a bearing frame;

- a work surface supported by said bearing frame;

- a loading and folding station disposed on the work surface;

- a folding unit disposed in the loading and folding station for loading and folding the pocket to be sewn on the fabric;

- a sewing station disposed on the work surface;

- a sewing unit disposed in the sewing station for sewing the pocket on the fabric;

- a sewing template disposed on the work surface. The peculiarity of the sewing machine according to the invention consists in the fact that the sewing template is fixed and disposed in the sewing unit.

The sewing machine also comprises:

- a loading gripper that is disposed on the work surface and is different and separate from the sewing template;

- moving means of said loading gripper, which are connected to the loading gripper and configured in such a way to move the loading gripper between a first end-stop position in the loading and folding station and a second end-stop position in the sewing station.

An additional purpose of the present patent for industrial invention is a method for sewing a pocket on fabric; said method comprising the following steps:

a) positioning a loading gripper in an idle position, between a first end- stop position in a loading and folding station and a second end-stop position in a sewing station;

b) loading the fabric on a work surface in the loading and folding station;

c) loading the pocket to be sewn on a plate of a folding unit;

d) folding the pocket on the plate by means of the folding unit;

e) lowering the plate of the folding unit and positioning the folded pocket over the fabric;

f) moving the loading gripper from the idle position to the first end-stop position in the loading and folding station in order to take the fabric and the folded pocket that is positioned over the fabric,

g) removing the plate of the folding unit from the folded pocket;

h) moving the loading gripper from the first end-stop position to the second end-stop position in the sewing station;

i) unloading the fabric and the folded pocket that is positioned over the fabric by means of the loading gripper under a sewing template of the sewing unit;

I) lowering the sewing template over the fabric and over the pocket ; m) moving the loading gripper from the second end-stop position to the idle position and simultaneously sewing the pocket on the fabric by means of the sewing unit.

Additional features of the invention will be manifest from the detailed description below, which refers to merely illustrative, not limiting embodiments, wherein:

Fig. 1 is a perspective view of the sewing machine of the invention; Fig. 2 is a perspective view of a variant of the sewing machine of Fig.

1 ;

Figs. 3, 4, 5, 6 and 7 are perspective views of the sewing machine of

Fig. 1 during the working steps.

With reference to the attached figures, the sewing machine according to the present invention is disclosed, which is generally indicated with reference numeral (1 ).

It must be noted that, although the following description refers to sewing a pocket (60) on fabric (6), the sewing machine of the invention can be advantageously used for sewing any other type of apparel component or element, such as buttons, buttonholes or the like, on a generic apparel item.

With reference to Fig. 1 , the sewing machine (1 ) of the invention comprises a bearing frame (T) and a work surface (10) supported by said bearing frame (T).

The work surface (10) is rectangular and has one longitudinal axis (X) and four sides:

- a longitudinal front side (100) where an operator is disposed in order to load and position a piece of fabric (6) on the work plate (10),

- a longitudinal back side (101 ) in opposite position to said front side (100), and

- two transverse sides (103, 104) in parallel position and orthogonal to the front and to the back side (100, 101 ).

A loading and folding station (SP) and a sewing station (SC) are disposed on the work surface (10). A folding unit (5) is disposed in the loading and folding station (SC) for loading and folding the pocket (60) to be sewn on the fabric (6), as shown in Fig. 3. More precisely, said folding unit (5) comprises a plate (4) that acts as template to support and fold the pocket (60) to be sewn on the fabric (6).

A sewing unit (2) is disposed in the sewing station (SC) to sew the pocket (60) on the fabric (6). In particular, the sewing unit (2) comprises a sewing head (22) suitable for sewing the pocket (60) on the fabric (6). Moreover, the sewing unit (2) comprises a sewing template (20) disposed over the work surface (10) and under the sewing head (22).

Said sewing template (20) is fixed, that is to say mounted on the work surface (10) in such a way to exclusively make vertical and transverse travels relative to the longitudinal axis (X) of the work surface, without the possibility of making lateral translations towards the loading and folding station (SP).

The sewing template (20) is suitable for being disposed over the fabric (6) and over the pocket (60) in order to hold the pocket (60) on the fabric (6) and sew the pocket (60) to the fabric (6).

With reference to Fig. 1 , the sewing machine (1 ) comprises a loading gripper (3) that is different and separate from the sewing template (20) of the sewing unit (2).

In particular, the loading gripper (3) is slidingly mounted on the work surface (10) in order to transport the fabric (6) and the pocket (60) disposed over the fabric (6) from the loading and folding station (SP) to the sewing station (SC) under the sewing template (20) of the sewing unit (2).

The loading gripper (3) is shaped as a plate and comprises a housing (3a) shaped as a pocket, with slightly smaller dimensions than the pocket, in such a way that the loading gripper is disposed over the perimeter edge of the pocket (60) that is folded on the fabric (6). In view of the above, when the loading gripper (3) moves the fabric (6) and the pocket (60) from the loading and folding station (SP) to the sewing station (SC), the pocket (60) does not change its position relative to the fabric (6). With reference to Figs. 4 - 7, when in idle position, the loading gripper (3) is disposed on the work surface (10) in intermediate position between the loading and folding station (SP) and the sewing station (SC).

Moving means (30) of the loading gripper (3) are connected to the loading gripper (3) and configured in such a way to move the loading gripper (3) in forward and backward travels along an axis that is parallel to the longitudinal axis (X) of the work surface (10). More precisely, said moving means (30) are configured in such a way to move the loading gripper (3) between a first end-stop position in the loading and folding station (SP) and a second end-stop position in the sewing station (SC).

In view of the above, during its travels between the two end-stop positions, the loading gripper (3) never passes through the loading and folding station (SP), thus making it easier for the operator to load the fabric (6) on the work surface. As a matter of fact, as soon as the loading gripper (3) leaves the loading and folding station (SP) and moves towards the sewing station (SC), the operator can load a new piece of fabric (6) on the work surface, without having to wait until the sewing of the pocket (60) on the fabric (6) is completed by the sewing template (20).

The moving means (30) of the loading gripper (3) comprise a support arm (31 ) that supports the loading gripper (3). Guide means (33) are connected to the support arm (31 ) to move the support arm (31 ) in parallel direction relative to the work surface (10). In particular, the support arm (31 ) is fixed to the guide means (33) in such a way to project above said work surface (10). Moreover, lifting means (not shown in the attached figures) are connected to the loading gripper (3) to move said loading gripper (3) in orthogonal direction relative to the work surface (10).

With reference to Fig. 1 , the guide means (33) are disposed in the front side (100) of the work surface (10). In such a case, the support arm (31 ) is suitably dimensioned in order not to interfere with the sewing template (20) during the movement of the loading gripper (3) from the loading and folding station (SP) to the sewing station (SC). In particular, the support arm (31 ) has suitable dimensions and volume for passing under the sewing template (20), as shown in Fig. 6.

Alternatively, the guide means (33) can be disposed in the front side (101 ) of the work surface (10), as shown in Fig. 2.

In such a case, the guide means (33) are disposed above the work surface (10) at a sufficient height to avoid any possible interference of the support arm (31 ) with the folding unit (5) and with the sewing unit (2). Such a position of the guide means (33) leaves the front side (100) of the work surface (10) substantially free, thus making it easier for the operator to charge the pieces of fabric (6) on the work surface.

Although it is not shown in the attached figures, said guide means (33) can be also positioned under the work surface (10), in such a way not to be visible. In such a case, a groove must be provided on the work surface (10) to connect the guide means (33) to the support arm (31 ) and to let the support arm (31 ) translate.

With reference to Fig. 1 , the guide means (33) advantageously comprise:

- a trolley (32) joined to the support arm (31 ), and

- a track (34), which is directed along a direction that is parallel to the longitudinal axis (X) of the work surface (10) whereon said trolley (32) slides.

Alternatively, said guide means (33) can comprise an endless screw with axis of rotation parallel to the longitudinal axis (X), which is connected to the support arm (33) and moved by an electric motor.

The description continues with reference to the method for sewing a pocket (6) on fabric (60) using the sewing machine (1 ) of the invention.

With reference to Figs. 3-7, said method comprises the following steps: a) positioning the loading gripper (3) in an idle position between the first end-stop position in the loading and folding station (SP) and the second end-stop position in the sewing station (SC);

b) loading the fabric (6) on the work surface (10) in the loading and folding station (SP); c) loading the pocket (60) to be sewn on a plate (4) of the folding unit

(5);

d) folding the pocket (60) on the plate (4) by means of the folding unit

(5) ;

e) lowering the plate (4) of the folding unit and positioning the folded pocket (60) on the fabric (6);

f) moving the loading gripper (3) from the idle position to the first end- stop position in the loading and folding station (SP) in order to take the fabric

(6) and the folded pocket (60) that is positioned on the fabric (6),

g) removing the plate (4) of the folding unit (5) from the folded pocket

(60);

h) moving the loading gripper (3) from the first end-stop position to the second end-stop position in the sewing station (SC);

i) unloading the fabric (6) and the folded pocket (60) that is positioned on the fabric (6) by means of the loading gripper (3) under the sewing template (20) of the sewing unit (2);

I) lowering the sewing template (20) on the fabric (6) and on the pocket

(60);

m) moving the loading gripper (3) from the second end-stop position to the idle position and simultaneously sewing the pocket (60) on the fabric by means of the sewing unit (2).

The advantages of the sewing machine according to the present invention are evident, it being provided with a fixed sewing template (20) and a loading gripper (3) that is different and separate from the sewing template.

In particular, as soon as the loading gripper (3) unloads the pocket (60) to be sewn and the piece of fabric (6) under the sewing template (20) of the sewing station (SC), said loading gripper (3) can immediately make a backward travel to the first end-stop position in the loading and folding station (SP), in such a way to take a new pocket to be sewn. Otherwise said, while the sewing unit (SC) sews the pocket (60) to the fabric (6), the loading gripper (3) can take a new pocket to be sewn in the loading and folding station (SP), thus consequently increasing the number of pockets that can be sewn in a given time interval.

Numerous equivalent variations and modifications can be made to the present embodiments of the invention, which are within the reach of an expert of the field, falling in any case within the scope of the invention.