Industrial sewing machine including two sewing units, respectively a first sewing unit having a horizontal needle bar and a second sewing unit having a vertical needle bar, for sequentially carrying out a joining sewing of two flaps of a cloth article, as well as a "riveting" sewing operation, after having laterally folded the cloth article flaps as sewn by the horizontal needle bar, are already known.

In the sewing machines of the above mentioned type, is very important to provide a feeding of the two flaps to be sewn without varying the mutual arrangement thereof, i.e. to hold the two flaps being sewn to a perfectly paired condition, so as to prevent, as far as possible, a flap from accidentally slipping with respect to the other.

In order to solve the above mentioned problem, the same Applicant has already proposed, in his Italian patent application MI96A-001700, a device provided upstream of the sewing units, including a guide body arranged above the surface bearing the cloth article to be sewn. This guide body has a substantially drop-like configuration, narrowing in the feeding direction of the cloth article being sewn, so as to cause the two flaps of the cloth article to be progressively moved toward one another in the direction of the first sewing unit.

The end portion of said guide body facing the first sewing unit is moreover provided with a pair of conveyor rollers, which can idly turn about their respective vertical axes operating to guide the two perfectly paired fabric flaps.

The sewing machine provided with the above mentioned device has been found to be susceptible of further improvements, for providing a very accurate feeding or supplying of the two flaps of the cloth article to be sewn, mainly in the case of a comparatively high thickness fabric, for example the fabrics conventionally used for making jeans cloth articles.

SUMMARY OF THE INVENTION Accordingly, the aim of the present invention is to provide an improved sewing machine, specifically designed for performing two subsequent seams, respectively a joining seam and a riveting seam, on high thickness fabrics, while providing, during the sewing operation, a very accurate feeding of the two flaps of the cloth article to be sewn.

Within the scope of the above mentioned aim, a main object of the present invention is to provide such a sewing machine which is specifically adapted to prevent one of the two flaps of the cloth article to be sewn from slipping with respect to the other, during the sewing operation.

Another object of the present invention is to provide such a sewing machine which is very reliable in operation.

Yet another object of the present invention is to provide a sewing machine which does not require a continuous assistance of an operator for correcting possible offsets of the fabric material from set positions thereof, due to a uneven feeding of the two fabric flaps to be sewn.

According to one aspect of the present invention, the above mentioned mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by an improved industrial sewing machine, specifically designed for carrying out two sequential seams, respectively a joining and a riveting seam, on large thickness fabrics, comprising two sewing units, respectively a first sewing unit having a horizontal needle bar and a second sewing unit having a vertical needle bar, sequentially arranged along a cloth article to be sewn feeding direction, said sewing machine comprising moreover, upstream of said first sewing unit, a conveyor device including a pair of conveyor rollers cooperating with two guide surfaces in order to cause the two flaps of the cloth article to be sewn to be arranged in an adjoining relationship in a substantially vertical plane.

This machine is characterized in that it comprises moreover driving means for driving the cloth article to be sewn, said driving means being arranged downstream of said second sewing unit, as well as conveyor and guide means provided with driving needle, to be engaged with said two fabric flaps and arranged

upstream of said conveyor rollers to cause the two fabric flaps to be sewn to be fed under a guided perfectly paired condition up to said conveyor rollers.

BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the sewing machine according to the present invention will become more apparent hereinafter from the following detailed disclosure of the preferred, though not exclusive, embodiment thereof, which is illustrated, by way of a merely indicative, but not limitative, example, in the figures of the accompanying drawings, where: Figure 1 is a perspective view illustrating the sewing machine according to the present invention; Figure 2 is a schematic top plan view illustrating the zone of the sewing machine arranged upstream of the first sewing unit thereof; Figure 3 is a detailed view illustrating the part of the sewing machine shown in Figure 2; Figure 4 is a perspective view illustrating the zone of the sewing machine arranged immediately upstream of the first sewing unit; Figure 5 is a top plan view illustrating a guide body including conveyor and guide means, shown under a first operating condition; Figure 6 is a view similar to Figure 5, with the conveyor and guide means being shown under another operating condition; Figure 7 is a cross-sectional view, illustrating a detail of the conveyor and guide means; Figure 8 is a cross-sectional view

substantially taken along the section line VIII-VIII of Figure 7; Figure 9 illustrates a feeding gripper of the sewing machine according to the present invention, being represented partially cross-sectioned; Figure 10 is a cross-sectional view of Figure 9, substantially taken along the section line X-X; Figure 11 is a further cross-sectional view of Figure 9, substantially taken along the section line XI-XI; Figure 12 is a perspective view illustrating a detail of Figure 11; Figure 13 is a further perspective view illustrating a folding ram or lug for folding the fabric material arranged between the first sewing unit and second sewing unit; Figure 14 is a further perspective view illustrating the driving means for driving or entraining the cloth article and arranged downstream of the second sewing unit; Figures 15 and 16 are further perspective views illustrating a cutting device for cutting the sewn chain into two different operating positions; Figure 17 is a front elevation view illustrating the device of Figures 15 and 16; and Figures 18 and 19 are top plan views illustrating the supplying or feeding of a cloth article to be sewn by the sewing machine according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the number references of

the above mentioned figures, the sewing machine according to the present invention, which has been generally indicated by the reference number 1, comprises, in a per se known manner, a first sewing unit 2 having a horizontal needle bar and a second sewing unit 3 having a vertical needle bars, said sewing units being sequentially arranged along the feeding or supplying direction of the cloth article 50 to be sewn, indicated in Figure 2 and being marked by the reference number 4.

The two sewing units 2 and 3 can be driven in order to respectively carry out a joining seam of the two flaps 50a and 50b of the cloth article 50 to be sewn, as well as a riveting or clamping seam, as it will become more apparent hereinafter.

Upstream of the first sewing unit 2 is provided a conveyor device, generally indicated by the reference number 5, comprising a guide body 6 which has a substantially drop-like configuration, and is progressively narrowed in the direction of the first sewing unit 2.

The guide body 6 defines, by the lateral sides thereof, two lateral or side guide surfaces 7a and 7b which progressively moves towards one another in the direction of the first sewing unit 2.

At the end of the guide body 6 facing the first sewing unit 2, a conveyor roller pair 8a and 8b is arranged, the conveyor rollers being rotatably arranged about substantially vertical axes.

The side surface of the conveyor rollers 8a and 8b is provided with a plurality of helical ribs, which, as the conveyor rollers 8a and 8b are rotatively driven about their respective axes, will

provide a pulling force and the two fabric flaps 50a and 50b of the cloth article 50 to be sewn, downwardly directed, or directed in the direction of the fabric bearing surface 90, which extends substantially horizontally.

The guide body 6 is provided, at the end thereof facing the first sewing unit 2, with a pair of recesses 9a and 9b which houses partially therein the two conveyor rollers 8a and 8b.

The guide body 6 is mounted on a slide 10, which, as driven by a pneumatic driving cylinder 11, can slide either towards or away from the first sewing unit 2.

The conveyor rollers 8a and 8b can be driven either toward or away from one another in order to facilitate the insertion of the two fabric flaps 50a and 50b of the cloth article 50 to be sewn between said conveyor rollers 8a and 8b and the guide body 6.

More specifically, the conveyor roller 8a is idly supported about the axis thereof by a supporting lever 12 which is pivoted to the machine framework, about an axis 12a, substantially vertical and spaced from the axis of the conveyor roller 8a.

The other end of the lever 12 is coupled to the rod 13a of the piston of a pneumatic cylinder 13, which can be driven to cause the lever 12 to swing and accordingly to cause the conveyor roller 8a to be driven either toward or away from the conveyor roller 8b.

The conveyor roller 8b is, in turn, mounted on a slide 14 which can slide, under the control of a pneumatic cylinder 15, along a direction 16 which is transversal and suitably slanted with respect to the

cloth article feeding or supplying direction 4, in order to cause the conveyor roller 8b to be displaced either toward or away from the conveyor roller 8a.

Downstream of the sewing units 2 and 3, are provided driving or entraining means 20 for driving the cloth article 50 to be sewn, and, upstream of the conveyor rollers 8a and 8b, conveyor and guide means are moreover provided for preventing the two flaps 50a and 50b of the cloth article 50 to be sewn from accidentally displacing.

The conveyor and guide means are provided with entraining or driving needles, engaging with the two flaps 50a and 50b of cloth article 50 to be sewn, as it is fed to the conveyor rollers 8a and 8b.

More specifically, the conveyor and guide means comprise a pair of guide bars 2la and 2lb which extend parallel to the guide side surfaces 7a and 7b and which are provided, at the end thereof facing the first sewing unit 2, with a plurality of needles 80, facing the bearing surface 90 and being adapted to punch the fabric of the two flaps 50a and 50b of the cloth article being sewn.

The remaining part of the guide bars 21a and 21b is slidably engaged in sliding guides 22a and 22b, which are coupled to the top of the guide body 6, near the side guide surfaces 7a and 7b.

The sliding guides 22a and 22b are pivoted to the guide body 6, so as to swing in a vertical or slanted plane, in order to cause the end portions of the guide bars 21a and 2lb, including the needles 80, to be lowered or raised on the bearing surface 90, in order to either engage or disengage said needles 80 with/from the fabric materials of the two flaps 5a and

5b to be sewn.

The swinging movement of the sliding guides 22a and 22b is obtained by a pneumatic cylinder 23, vertically arranged and associated with the guide body 6. The rod of the pneumatic cylinder 23 piston is coupled, by a cross-member 24, to the sliding guides 22a and 22b.

The translation movement of the guide bars 21a and 21b in the direction of the first sewing unit 2 is counter-biassed by urging springs 25a and 25b which are housed or engaged in the same sliding guides 22a and 22b.

In operation, as the end portions of the guide bars 21a and 21b are lowered on the bearing surface 90 and accordingly engaged with the two flaps 50a and 50b of the cloth article to be sewn, the entrainment of the cloth article 50 will cause the two flaps 50a and 50b of said cloth article 50 to be fed in a paired or coupled condition, as engaged by the needles 80 of the guide bars 21a and 21b, as counter- biassed by the urging springs 25a and 25b.

The raising of the guide bars 21a and 21b, due to the operation of the pneumatic cylinder 23, will cause the needles 80 of the guide bars 21a and 21b to disengage from the fabric, thereby the urging springs 25a and 25b will cause said needles to withdraw inside the sliding guides 22a and 22b, as it will become more apparent hereinafter.

The other elements of the guide body 6, which correspond to the elements already disclosed with reference to the Italian patent application MI96A-001700, will not be herein disclosed in further details and, for a full disclosure thereof, reference should be made to the mentioned Italian patent application.

Between the guide body 6 and first sewing unit 2 feeding or supplying gripper generally indicated by the reference number 30 are arranged.

Said feeding or supplying grippers substantially comprise toothed grippers 31, abutting on a plate 32. The grippers 31 are provided, interleaved through the tooth elements thereof, with needles or pointed elements 33, provided for punching through the two paired fabric flaps 50a and 50b to be sewn.

In order to provide a very efficient engagement of the needles or pointed elements 33 and the fabric, the plate 32 is provided, at said needles or pointed elements, with suitable slots 34.

The grippers 31 are driven by driving means which are not herein disclosed for simplicity.

Immediately downstream of said gripper 30, a foot element 36 is provided, thereon the first sewing unit 2 operates.

Between the first sewing unit 2 and second sewing unit 3, is provided a contoured spur or lug 37, operating to laterally fold the two fabric flaps 50a and 50b joined by the seams carried out by the first sewing unit 2, to set said fabric flaps for a subsequent riveting or clamping sewing operation, performed by the second sewing unit 3, with the vertical needle bar.

The driving or entraining means 20 comprise moreover, immediately upstream of the driving roller 40, a track conveyor 44, substantially comprising a toothed belt, provided with a plurality of tooth

element the inner side thereof, bearing with its outside portion or side, for a length of the extension thereof, on the bearing or supporting surface 90.

The track conveyor 44 is entrained on pulleys 45, 46 and 47 at least one of which is rotatively driven about its rotary axis, so as to cause the track conveyor 44 to be driven in that direction allowing the cloth article 50 to be sewn, arranged between the track conveyor 44 and bearing surface 90, to be fed.

The track conveyor 44 may be in turn raised or lowered with respect to the bearing or supporting surface 90, by a suitable pneumatic cylinder 48, to allow the cloth article 50 to be sewn to be arranged at the start of the sewing operation.

The entrainment roller 40 is coupled, by a toothed or cog belt 49, to one of the pulleys 45, 46, 47 and is rotatively driven about its rotary axis in a timed relationship with the entrainment or driving of the track conveyor 44.

Immediately upstream of the track conveyor 44, cutting means for cutting the sewing chain are provided.

Said cutting means comprise a scissors element 51 which, in a rest or idle position thereof, is arranged at the bottom of the bearing or supporting surface 90, at a suitable window 52 therethrough said scissors member 51 can be withdrawn as it must cut the chain 53.

More specifically, the two legs of the scissors member 52 are pivoted to the end sides 54 and 55 of a double articulated quadrilateral arrangement supported by a suitable supporting framework 56. On

said supporting framework 56 is moreover arranged a pneumatic cylinder 57 operating, by the rod of its piston, on the scissors member 51 in order to cause the latter to be raised or lowered. Due to the articulated linkage coupling the scissors member 51 and framework 56, as the scissors member 51 is raised by the pneumatic cylinder 57, the two legs of said scissors member 51 will be closed, thereby cutting the sewing chain 53.

Near the track conveyor detecting means are provided for detecting the start and end portion of the cloth article 50 to be sewn.

Said detecting means can comprise photocells 58 and 59 mounted on the framework of the track conveyor, which photocells cooperate with reflecting plates suitably arranged on the supporting surface 90 at the bottom of the photocells 58 and 59.

As one of said photocells detects an arriving starting portion of the cloth article 50 to be sewn, then said photocells will operate the scissor member 51, which will operate in order to cut the start position of the chain 53.

As the other photocell detects the end of the cloth article to be sewn, then it will operate the scissors member 51 for cutting the end of the sewing chain 53. As the scissors member 51 is not used, i.e. during the sewing operation for sewing the cloth article 50, then it will be held at the bottom under the supporting surface 90, in order not to hinder the feeding of the cloth article 50 being sewn.

Near the conveyor rollers 8a and 8b, are provided reference light tracks or paths 61 for properly locating transversal or cross seams 62 already carried out on the two flaps 50a and 50b of the cloth article 50 to be sewn, as it will become more apparent hereinafter.

Moreover, on the upwardly directed side of the guide bars 21a and 21b light reflecting plates are provided, which cooperate with suitable photocells for the maximum feeding of said guide bars 21a and 21b to operate the pneumatic cylinder 23 so as to raise the guide bars 21a and 21b thereby disengaging said bars from the flaps 50a and 50b of the cloth article 50 to be sewn.

The sewing machine according to the present invention operates as follows: The two fabric flaps 50a and 50b are at first arranged at the side guide surfaces 7a and 7b, whereas the conveyor rollers 8a and 8b are arranged in a moved away position thereof, and the guide body 6 being withdrawn or rearwardly displaced with respect to the first sewing unit 2. During the positioning operation, the guide bars 21a and 21b are suitably raised to simplify, as far as possible, the manual operation for inserting and locating the two fabric flaps 50a and 50b of the cloth article to be sewn.

Then the conveyor rollers 8a and 8b are driven toward one another by operating the pneumatic cylinders 13 and 15, and the guide body 6 is frontward displaced by operating the pneumatic cylinder 11. At the start of the feeding displacement of the article 5a to be sewn, the guide bars 21a and 21b are lowered toward the supporting surface 90, thereby punching the two fabric flaps 50a and 50b of the cloth article to be sewn, while starting the sewing operation thereon.

The feeding of the cloth article 50 will

cause the guide bars 21a and 21b to be driven in the direction of the first swing unit 2 and, as the guide bars 21a and 21b are arrived at their position nearest to the first sewing unit 2, then the pneumatic cylinder 23 will be operated to raise the guide bars 21a and 21b, thereby causing said guide bars to disengage from the fabric flaps 50a and 50b, said bars being successively withdrawn under the action of the urging springs 25a and 25b inside the sliding guides 22a and 22b.

As the starting part of the fabric has passed the second sewing unit 3, the scissors member 51 will cut, as already disclosed, the starting part of the sewing chain 53, and the cloth article 50 will be driven to the bottom of the track conveyor 44 and the entrainment or driving roller 40, which will be then lowered by operating the pneumatic cylinder 43, in order to engage the fabric for continuously driving it.

At the end of the sewing operation, the scissors member 51 will be actuated again in order to cut the end portion of the sewing chain 53.

In this connection it should be pointed out that, during the feeding of the cloth article 50, the guide bars 21a and 21b will provide, by their needles 80, a very accurate conveying and guiding operation, efficiently preventing any offset of a fabric flap with respect to the other.

The feeding gripper 30, moreover, by their needles or pointed elements 33, will hold the two fabric flaps 50a and 50b to be sewn in a proper paired or coupled condition.

Thus, a very accurate joining and riveting

sewing operation of comparatively large thickness fabrics, in particular the jeans fabrics, can be carried out.

From the above disclosure and from the observation of the figures of the accompanying drawings, it should be apparent that the invention fully achieves the intended aim and objects.

In particular, it should be apparent that an improved sewing machine has been provided, adapted to perform a very accurate joining and riveting operation on high or large thickness fabrics, without requiring any assistance of an operator for holding properly paired the two flaps of the fabrics to be sewn.

While the invention has been disclosed and illustrated with reference to preferred embodiments thereof, it should be apparent that the disclosed embodiments are susceptible to several modifications and variations, all of which will come within the scope of the accompanying claims.