METHOD OF MACHINE SEAM FOR HIGH THICKNESS THREADS

Technical Field

The present invention refers to the technical field of tailoring. In particular it refers to an innovative method of machine seam that allows the use of high thickness threads.

Further, the present invention describes a machinery for realizing such method. Background Art

Sewing machines, either for domestic use or industrial use, have long been known. The functioning principle is basically the same for both types of machines, except for the fact that the machines for industrial use are usually much more accessorized, technologically more advanced and yield more compared to the domestic ones.

Independently from the type of machine used, the machines in question allow to make varied tailoring jobs such as the making of hems and the sewing of buttons. Especially in the industrial field, they are also used for making the integral sewing of articles. A typical example is found in the sewing of the sleeves of a jacket to the central part of same. In brief, a sewing machine comprises a superior portion and an inferior portion. The superior portion comprises a spool holder within which a superior thread spool is mounted in a revolving way. The thread is passed through appropriate thread guides that guide it to the needle. The needle is then provided with a hole at its top in which the thread is inserted. In such a way a first independent thread path is realized that from the top is directed towards the sewing plane by means of the needle.

The low part of the machine, or rather that which is placed under the sewing plane, essentially comprises a revolving bobbin-box inserted in an appropriate seat called socket in combination with a socket ring. The bobbin-box holds inside a removable thread bobbin. The top of the thread wound in the bobbin is passed towards the exterior from the bobbin-box itself through an intaglio and an adjustable latch and that allows the adjustment of the right tension of the thread. It was thus realized a second independent thread path that from the bottom goes out from the bobbin-box towards the sewing plane.

The particular combination of kinematic motion of the needle that penetrates the fabric and the rotation of the bobbin-box together with the socket ring allows to make a combined sewing. Nevertheless, such machines have always had a structural limit that has obliged everyone to the use of extremely thin threads and of a standard material, typically cotton. In fact, either the structure of the needle itself or the structural conformation of the thread guides have always impeded the use of high thickness threads of a different nature. Last but not least, the structure itself of the spool holder as well does not allow the use of high thickness threads, thus significantly limiting the possibilities of choice and production.

Disclosure of invention

It is therefore the aim of the present invention to provide a method and the relative sewing machine that overcomes the above mentioned inconveniences. In particular it is the aim of the present invention to provide a seam method that allows the use of high thickness threads.

It is also the aim of the present invention to provide a seam method that allows to obtain a valuable aesthetic effect, highlighting the type of high thickness thread used and in such a way that this stands out in respect to the other threads used and without because of this requiring significant and expensive modifications of the existing machine or very complex and expensive new machines .

These and other aims are therefore obtained with the present method for making the machine seam of articles in general, said sewing machine comprising a head (3), an inferior section (8) and a sewing plane (7) interposed between said head and said inferior section, and where the method comprises the operations of:

- Insertion of a superior reel (5) on the head of the sewing machine and successive passage of the thread (5) wound around the reel through the thread guide of the machine to the sewing needle;

- Preparation of an inferior bobbin (10) and its successive insertion inside the bobbin-box (9) in such a way so as to obtain a whole bobbin-box (15); - Insertion of the whole bobbin-box (15) in correspondence of the inferior section (8) of the sewing machine;

- Prearrangement of the article to be sewed on the sewing plane (7) and successive machine seam of the article; and characterized by the fact that the operation of preparation of the inferior bobbin (10) comprises the operation of winding of a leather thread (16) on said bobbin and where the operation of sewing of the article is made on the reverse side so that the leather thread is at sight on the article.

According to the present method, therefore, the winding of a leather thread around the inferior bobbin allows the realization of particular and new leather thread seams that could not be obtained otherwise and that -A- are interlaced with the common threads coming from the bobbin of the head. In particular the seam of the article with the mentioned leather thread on the reverse side allows that the leather thread is at sight. In such a way, the leather seam gives a valuable and ornamental surplus value to the article that is worn.

Naturally, the realization of the present method without necessarily sewing on the reverse side is anyway possible without because of this moving away from the present inventive concept. In such a case, the visual effect of the leather seam made will be much reduced, but the making of the machine seam is still possible with the leather thread prearranged on the inferior bobbin.

Advantageously, the winding of the thread is made in such a way so as to fill the inferior bobbin, said leather thread being then passed from the inferior bobbin through a lifted latch (20) .

The invention also comprises the product obtained with such method and consisting of an article of clothing that presents at least a machine seam made with a leather thread sewed on the reverse side. In particular the article of clothing is made of denim fabric.

It is further described here the relative machine for making possible such method, or rather a sewing machine (1) comprising:

- At least a head (3) comprising a spool holder (4) for mounting in use a spool (5) on which is wound a first sewing thread (5);

- Means of passage (6) of the thread for guiding said first thread from the spool (5) to the needle of the machine;

- At least an inferior section (8) comprising a whole bobbin-box (15) from which a second sewing thread (16) unwinds; - At least a sewing plane (7) interposed between the head and the inferior section and on which said first and said second sewing thread converge; and where the second sewing thread (16) is a continuous leather thread (16) and the whole bobbin-box (15) comprise lift mechanisms (21) in such a way so as to allow the coming out of the leather thread (16) from the bobbin-box towards the sewing plane.

A machine thus structured is a constructively simple machine and that does not require the use of expensive technology in order to consent the use of a leather thread on same for realizing the seam.

Advantageously, the lift mechanisms (21) comprise at least a shim (21) on which a latch (20) is prearranged.

Further, the latch is fixed on the shim (21) by means of a screw.

Advantageously, the whole bobbin-box (15) comprises a bobbin-box (9) within which an inferior bobbin (10) is inserted, the thickness being interposed between the bobbin-box (9) and the latch. Naturally, nothing prohibits a solution in which the latch is integral to the bobbin-box and is lifted from it as described.

Advantageously, the leather thread (16) comprises a core, for example of cotton, Nylon or similar materials. It is also described here the whole bobbin-box (15) for a sewing machine (1) as described above, said sewing machine comprising:

- At least a head (3) comprising a spool holder (4) for mounting in use a spool (5) on which a first sewing thread (5) is wound;

- Means of passage (6) of the thread for guiding the first thread from the spool (5) to the needle of the machine;

- At least an inferior section (8) destined in use for holding in a removable way said whole bobbin-box (15) from which a second sewing thread (16) unwinds;

- At least a sewing plane (7) interposed between said head and said inferior section and on which said first and said second sewing thread converge. and where said whole bobbin-box (15) comprises lift mechanisms (21) in such a way- so as to allow the coming out of the leather thread (16) from said bobbin box towards the sewing plane. It is therefore evident how, modifying the latch, the passage of the leather thread also in a traditional machine is easily realized and therefore made possible, without resorting to important modifications of said machine . For that purpose it is also described here a method for modifying a traditional sewing machine comprising the operation of application of a shim (21) in correspondence of the bobbin box (9) containing the inferior bobbin (10) in such a way so as to lift the latch (20) and make the thread come out and consequently allow the winding on the inferior bobbin of a leather thread.

Brief description of the drawings

Further features and advantages, according to the invention, will be clearer with the description of some of its embodiments that follows, made to illustrate but not limit, with reference to the annexed drawings, where:

- Figure 1 represents an axonometric view of a common sewing machine;

- Figure 2 schematically represents in detail the sewing plane of the machine together with the inferior section of the machine;

- Figure 3 and figure 4 schematically represent in an axonometric view the whole of an inferior bobbin 15 to be inserted in use in its containing socket and the whole itself of the inferior bobbin 15 dismounted according to a bobbin box 9 and inferior bobbin 10;

- Figures from 5 to 7 represent a functioning sequence of a sewing machine and the prearrangement of the threads according to the present invention;

- Figure 8 represents the position of the article to be sewed on the machine according to the present invention;

- Figure 9 represents the sewing made on the article;

- Figure 10 represents a constructive detail of a new latch applied to the bobbin box 9 relative to the whole bobbin box 15.

Description of a preferred embodiment

Figures 1 and 2 schematically represent a typical sewing machine 1, either for domestic use or industrial use. Naturally, the sewing machine described below is only- intended to illustrate and therefore not limit the present invention. In particular (see figure 1), the machine altogether comprises a superior portion, or head 3, on which a spool holder 4 is mounted. On the spool holder is then rotatable inserted a thread spool 5. The thread unwound from the spool is passed, thank to means of passage such as the thread guides, through all the frame of the machine up to reaching the needle. In particular figure 1 schematically indicates one or more thread guides 6 that guide the thread from the spool to the needle.

As it is well known, the needle reacts on a base that realizes a sewing plane 7 of the machine (well seen in figure 1) and where the article to be sewed is placed. A section 8 placed under the sewing plane (see figure 2) serves to hold a whole bobbin box 15 comprising a bobbin box 9 in which an inferior bobbin 10 of thread is inserted

(see figure 3 and figure 4) . In particular figure 2 represents, just to illustrate, a possible opening direction of a door precisely to allow the insertion of the bobbin box in the appropriate section 8. The bobbin box 9, once coupled to the bobbin 10, is therefore inserted in a revolving way in a socket, not represented in a figure for simplicity purposes, integrated inside the inferior section 8. Figure 4 represents in particular the coupling of the bobbin box 9 with the inferior bobbin 10.

Being the machine prearranged according to what has just been described, therefore, it is possible to proceed with the normal seam of the article. For that purpose, the sequence of figures from 5 to 7 represent very schematically the functioning principle of sewing machines. In particular, a revolving socket ring 12 grasps the superior thread 13 inserted in the hole at the top of the needle, catching it around the inferior thread 16 that unwinds from the whole bobbin box 15 and inserted in the socket in a revolving way. In this way the inferior thread 16 is knotted to the superior thread 13 through the section 17 of the article to be sewed, thus making the sewing. According to the present innovative method (see figure 3 and 4), it is possible to make the sewing of the article using a leather thread 16 wound around the bobbin 10 rather than a common cotton thread or a thread of similar materials. In such a way (see figure 5), the leather thread is inserted from the part of the inferior side 18 of the fabric to be sewed through its entire section 17 (for example the sleeve of a jacket to be sewed to the central part of it) .

In addition, the leather thread used can also comprise inside a core of a different fabric, for example cotton or

Nylon, in order to increase the mechanic features of the thread itself.

The substitution, therefore, of a leather thread wound on the inferior bobbin rather than common cotton threads allows to make a leather seam not possible otherwise. It is indeed unthinkable a banal passage of leather thread from the top section of the machine, since no component of same can be modified in a simple way so as to hold the diameters that generally have leather threads, at least without incurring significant increases in costs and structural complications of the machine. To illustrate this, it is highlighted how the thickness of the leather thread is such so as not to allow its passage through the hole of the needle or through the common thread guides used.

The winding of a leather thread in correspondence of the bobbin 10, therefore, allows a mixed sewing with leather thread and common thread (the leather thread coming from the inferior bobbin and the common thread coming from the needle) .

The sewing just on one side with the leather thread gives much freedom as regards the choice of the sewing itself. In particular (see figure 8), in case it is desired that the leather seam is at sight when the article will be worn, it is necessary to sew the article on the reverse side. This means that the external side 18 of the article, or rather that which will be at sight once worn, has to lean on the sewing plane 7 during all the operation of sewing so that the leather thread is passed from the external side of the article through its section (see also figure 9) . Figure 8 represents in detail the direction of the article to be leant on the sewing plane while figure 9 represents the resulting leather seam 16. In such a case, the sewing will be seen since it will be prearranged on the external side of the article opposed to the internal side destined in use to be in contact with the body. The aesthetic effect is extremely valuable.

Generally, leather threads have much larger diameters than the usually used common threads (also superior to 2 mm) . For that purpose, a common latch of bobbin box 9 could not be appropriate for the purpose and could create significant difficulties for the passage of same to the external (see figure 3) . Generally, it is always necessary to unscrew it, pass the thread and then screw it again. For this purpose a simple modification of the latch 20 was provided, realizing same in such as way so as to leave a pass through light under same of the leather thread. Such solution eliminates the inconvenience of dismounting it and makes the present leather thread seam method easily possible, particularly on the reverse side. In detail, as described in figure 10, a solution in which the latch 20 is placed on appropriate lift mechanisms to lift same is provided. In particular a simple shim 21 can be provided joined to it with screws to lift it as needed. A sewing machine can therefore be provided prearranged in such a way so as to allow the use of a leather thread in correspondence of the whole bobbin box 15, as already described, or it is also possible to provide a modification on an existing machine opportunely modifying an existing whole bobbin box with a shim 21.

It is now clear how all the aims set by the present invention have been reached. It is particularly evident how the use of a leather thread wound around the inferior bobbin allows the making of machine leather seams that would otherwise be impossible. It is also evident how a sewing on the reverse side allows to make aesthetically valuable leather seams and that are seen from the external when the article is worn.