FIELD OF THE INVENTION

The present invention concerns a perfected multi-needled quilting machine, and in particular a multi-needled quilting machine suitable to cut the thread while leaving, on both the needle side and on the side of the lower sewing element such as a shuttle, a rotating crochet hook or an alternately mobile hook, the thread tail or length of thread needed to resume the subsequent sewing operations in order to make the patterns .

BACKGROUND OF THE INVENTION

It is known that in multi-needled quilting machines, in particular in multi- needled quilting machines which work with knotted stitch or double chain stitch, a considerable problem concerns cutting the floating thread which is generated during sewing operations .

In particular, it is known that, when the multi-needled quilting machine has to sew isolated patterns, also called "jump" patterns, floating threads are generated between one pattern and the next, both in the upper and lower part of the material being worked, which then have to be subsequently removed manually by an operator.

One example of a multi-needled quilting machine which integrates a device for cutting the threads is described in document US-A-5.154.130. This document discloses a machine provided with a work plane on which the material to be sewn is deposited and made to advance, and a presser device located above the work plane and suitable to keep the material pressed during working.

Below the work plane and in cooperation with each of the needles and the lower sewing members, a cutting device is provided suitable to cut the sewing threads.

This solution, however, does not allow to control how the threads are cut, that is, it does not allow to determine the thread tail which has to be present in the needles and in the lower sewing members for the subsequent restoration of sewing operations.

When the thread tail is too short, it can come out of the needle or the lower sewing members, so that sewing operations cannot be restored.

This solution is also particularly complex to make and manage.

One purpose of the present invention is to make a multi-needled quilting machine which allows to execute the cutting of the thread automatically, whether it is associated to the needle or to the lower sewing element.

Another purpose of the present invention is to make a multi-needled quilting machine which supplies the cut thread tail in the desired length to allow the subsequent restoration of sewing operations.

It is also a purpose of the present invention to make a multi-needled quilting machine which allows to execute the cutting of the thread automatically, either at the end of the sewing cycle or during sewing.

It is also a purpose of the present invention to make a system that is applicable simply and quickly to already existing multi-needled quilting machines.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, a multi-needled quilting machine according to the present invention, comprises a presser device, also called beater, and a work plane on which a material to be sewn runs during use.

Both the presser device and the work plane are each provided with a plurality of through holes so that the needles can pass through them. In the passage through the through holes, the needles cooperate in their turn with corresponding lower sewing elements, disposed below the work plane, to work, or rather quilt the material to be sewn as it advances between the presser device and the work plane. The lower sewing elements can be, merely by way of example, a crochet hook, a shuttle or a hook with alternate motion.

According to one feature of the present invention, a device to cut threads is associated to the work plane or the presser device, or possibly both, and is disposed longitudinally to occupy the whole space comprised between at least two of said through holes in order to cut threads passing through said at least two through holes and coming from corresponding lower sewing elements or respectively needles.

With the present invention it is in fact possible to automatically execute the cutting of the thread, whether it is coming from the lower sewing element or from the needle, even during the normal sewing cycle of a material to be sewn, thus allowing to eliminate immediately possible floating threads which can be present for example between patterns that are distanced from each other, such as for example "jump" patterns.

According to one form of embodiment of the present invention, the cutting device comprises at least a first bar provided with a plurality of apertures and a second bar, above the first bar and provided with a plurality of eyelets, each with a cutting element. It is provided that the apertures of the first bar and the eyelets of the second bar are made in such a manner that one of the apertures and one of the eyelets is associable to each of the through holes. Under normal working conditions the apertures, the eyelets and the through holes are disposed aligned with each other so that the needle can pass between them to execute the sewing.

By performing a translation of the first bar with respect to the work plane and to the presser device, a thread tail is generated in the needle and/or in the lower sewing element, of a desired length, predetermined on each occasion, which once the thread is cut and held guarantees the correct restoration of the sewing operations.

The translation of the second bar in its turn with respect to the first bar and to the work plane and/or the presser device causes the cutting of the thread tail previously generated by the first bar.

To this purpose, according to another form of embodiment, it is provided that respective movement means are associated to the first bar and second bar in order to selectively translate the first bar and second bar with respect to the presser device and to the work plane, so that one thread tail is formed and cut, on the needle side and/or on the lower sewing element side.

Some forms of embodiment provide that, if the cutting device is associated to the work plane, the second bar is disposed facing the work plane.

Other forms of embodiment provide that, if the cutting device is associated to the presser device, the second bar is disposed facing the presser device.

According to another form of embodiment, the cutting device comprises a containing bar mounted in a fixed position with respect to the work plane and/or the presser device, and facing the first bar. The containing bar is also provided with a plurality of through holes, each aligned to a corresponding through hole of the work plane and of the presser device. The containing bar contributes with the first bar to creating the thread tail.

The present invention also concerns the sewing method which uses a multi- needled quilting machine as described above.

DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of one form of embodiment, given as a non- restrictive example with reference to the attached drawings wherein:

- fig. 1 is a partial perspective view of a multi-needled quilting machine according to the invention;

- fig. 2 is a schematic view of a longitudinal section of part of the multi-needled quilting machine in fig. 1 ;

- fig. 2a is a view of a variant of a detail of fig. 2;

- fig. 2b is a variant of fig. 2a;

- fig. 3 is a schematic view in section of a first part of fig. 2 in a first operating condition;

- fig. 4 is a schematic view of fig. 3 in a second operating condition;

- fig. 5 is a schematic view of fig. 3 in a third operating condition;

- fig. 6 is a schematic view in section of a second part of fig. 2 in a its first operating condition;

- fig. 7 is a schematic view of fig. 6 in a second operating condition;

- fig. 8 is a schematic view of fig. 6 in a third operating condition.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one form of embodiment can conveniently be incorporated into other forms of embodiment without further clarifications.

DESCRIPTION OF SOME FORMS OF EMBODIMENT A perfected multi-needled quilting machine according to the present invention, only shown partly in fig. 1, is indicated in its entirety by the reference number 10.

The multi-needled quilting machine 10 comprises a row of needles 1 1 provided to carry out sewing operations according to a sewing program predefined and established by a command and control unit, not shown in the drawings.

The needles 1 1 cooperate, during use, with a mating lower sewing element 12, such as a shuttle (fig. 2), a mobile hook (fig. 2a) with alternate motion, or a rotating crochet hook (fig. 2b).

The multi-needled quilting machine 10 (fig. 1) comprises a work plane 13 on which, during use, a material to be sewn 14 (fig. 2) runs, and a presser device 15, also called beater, which is disposed above the work plane 13.

The presser device 15 has the function of holding the material to be sewn 14 during the execution of the stitches.

The presser device 15 is associated to a needle-carrier bar 16 on which a row of needles 1 1 is mounted and, together with the latter, moves with alternate motion to execute the stitches.

To this purpose substantially known movement means 17, which therefore will not be described hereafter, are associated to the presser device 15 and the needle- carrier bar 16 (fig. 1). Activation/de-activation devices can be associated to the needle-carrier bar 16 suitable to selectively activate the needles 1 1 associated to the needle-carrier bar 16.

Both the work plane 13 (fig. 2) and the presser device 15 are provided with through holes 18 and respectively 19 through which the needles 1 1 pass during the sewing operations.

To at least one of either the work plane 13 or the presser device 15, in this case both, a cutting device 20 is associated to cut the thread F coming respectively from the needles 1 1 or from the lower sewing elements 12.

In particular, the cutting device 20 associated to the work plane 13 is suitable to generate a thread tail and cut the thread F associated to the lower sewing element 12, while the cutting device 20 associated to the presser device 15 is suitable to generate a thread tail and to cut the thread F that is associated to the needle 1 1. The thread F tail which is generated in both cases has to be sufficiently long to allow to subsequently restore the sewing operations following an interruption for example, or following the re-activation of one of the needles 1 1 which were associated to the row of needles 11.

Each cutting device 20, whether it is associated to the work plane 13 or to the presser device 15, can comprise at least a first bar 21 and a second bar 22. The first bar 21 is suitable to generate a thread F tail of a desired length while the second bar 22 is suitable to cut the thread F.

It is quite clear that, in order to cut the threads, different configurations of cutting devices can be provided, other than a bar configuration as provided for the second bar 22.

The first bar 21 and the second bar 22 overlap each other and slide with respect to each other on respective sliding surfaces.

In its turn the second bar 22 is disposed resting and selectively sliding on the work plane 13 or on the presser device 15, depending on whether it is associated to the cutting device 20 of one or the other of the latter.

The first bar 21 and the second bar 22 have a mainly oblong development with a flat and rectangular cross section. Merely by way of example the first bar 21 and the second bar 22 have a thickness comprised between 0.5 mm and 3 mm, and a width comprised between 10 mm and 20 mm.

The first bar 21 is provided with a plurality of through holes or apertures 23, made according to the pattern of the through holes 18, 19 of the work plane 13, or of the presser device 15.

The second bar 22 has a plurality of through eyelets 24 with an elliptical shape even if, in other forms of embodiment, they could have a rectangular or elongated shape and a length that is at least greater than the diameter of the through holes 18, 19.

In the condition of active needles 1 1 suitable to sew stitches (figs. 3 and 6), the apertures 23 and the eyelets 24 are substantially aligned with the through holes 18 of the work plane 13, or respectively with the through holes 19 of the presser device 15.

Each eyelet 24 is provided, on its perimeter edge, with a cutting element 25 configured to cut the corresponding thread F passing through the through hole 18 or 19.

The cutting element 25 in this case is made directly in the perimeter edge of the eyelet 24 although it is not excluded that, in other forms of embodiment, the cutting element 25 is a separate and replaceable element, attached to the second bar 22 in correspondence to each eyelet 24.

First actuation or movement means 26 and respectively second actuation or movement means 27 are associated to the first bar 21 and the second bar 22.

The first actuation means 26 and the second actuation means 27 can comprise a pneumatic actuator, a hydraulic actuator, an electromagnetic actuator, an articulated mechanism, or other similar movement mean.

In other forms of embodiment it can be provided that common movement means are associated both to the first bar 21 and to the second bar 22 in order to provide their selective actuation, and possibly a temporally staggered actuation thereof in order to execute the operations described above.

The cutting device 20 is provided with a containing bar 28 disposed above the first bar 21 and mounted in a fixed position with respect to the work plane 13 or the presser device 15.

Between the first bar 21 and the containing bar 28 there is an interspace with sizes at least comparable to those of the thickness of the thread F.

The containing bar 28 is also provided with a plurality of through holes 30 disposed in a position mating with the position of the needles 1 1 and substantially aligned with the through holes 18 of the work plane 13 or with the through holes 19 of the presser device 15. In this way, during the normal sewing action, the needles 11 pass through the through holes 18 or 19, the eyelets 24, the apertures 23 and the through holes 30 to move into cooperation with the lower sewing element 12.

With reference to figs. 3-5 the functioning of the cutting device 20 is described, applied to the work plane 13 in order to cut the thread F associated to the lower sewing element 12, in this case the shuttle.

In the normal sewing condition (fig. 3) the through hole 18 of the work plane 13, the eyelet 24 of the second bar 22, the aperture 23 of the first bar 21 and the through hole 30 of the containing bar 28 are substantially aligned with respect to each other and the thread F coming from the shuttle 12 can cooperate with the thread F coming from the needle 1 1 in order to sew the stitches.

When the thread F requires to be cut, for example to make patterns in "jump" mode, the first actuation means 26 are actuated to translate the first bar 21 with respect to the work plane 13, to the second bar 22 and to the containing bar 28. Each of the apertures 23 (fig. 4) of the first bar 21 draws with it a segment of thread F coming from the shuttle 12. The entity of translation of the first bar 21 determines the length of thread F that remains associated to the shuttle 12 and that, after the thread F has been cut, allows the restoration of sewing operations.

Subsequently (fig. 5), the second actuation means 27 are activated to translate the second bar 22 with respect to the work plane 13 and to cut the thread F passing through the through hole 18.

With reference to figs. 6-8 the functioning of the cutting device 20 is described, applied to the presser device 15 in order to cut the thread F associated to the needle 1 1.

In normal sewing conditions the through hole 30 of the containing bar 28, the apertures 23 of the first bar 21, the eyelets 24 of the second bar 22 and the through holes 19 of the presser device are disposed aligned with respect to each other.

When the thread F associated to the needle 1 1 requires to be cut, the first actuation means 26 are actuated in order to translate the apertures 23 with respect to the through holes 30. During the translation, the first bar 21 draws with it a segment of thread F attached to the needle 1 1. The entity of translation of the first bar 21 determines its length.

Subsequently the second activation means 27 are activated so that the cutting elements 25 associated to each eyelet 24 cut the thread F passing through the through holes 30, generating a thread F tail associated to each needle 1 1.

In this way it is possible to cut the thread F tails, whether they are associated to the needle 1 1 or to the shuttle 12, both during sewing operations, for example in order to execute "jump" patterns, and at end-of-cycle. Moreover, with the present invention it is no longer necessary to require operators to finish off the material that has been quilted in order to remove possible floating thread tails or that connect one pattern to the next.

It is clear that modifications and/or additions of parts may be made to the perfected multi-needled quilting machine as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of perfected multi-needled quilting machine, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.