This sewing is generally carried out in machines comprising a cradle for receiving the fabric rolls, an unwinder and an exit lap folder or accumulator. Sewing is carried out manually with the aid of a sewing machine mounted on a carriage and driven by the operator via a pedal. After positioning the roll of tubular fabric in the cradle, the operator takes the rear end of the previously unwound piece, superposes it on the front end of the next piece and rotates them intermittently on the sewing machine until the entire circumference of the two tubular pieces has been completed.

On termination of sewing, the operator restarts the machine to totally unwind the roll, so leaving the rear end of the piece ready to be sewn to the front end of a new piece. This procedure has the following drawbacks: -relative slippage between the ends during sewing; -difficulty of obtaining parallelism between them; -unravelling and creasing of the fabric; continuos operator employment even during the sewing stage.

The main object of this invention is to obtain completely automatic sewing with the advantage of eliminating the aforelisted

drawbacks and reducing the proportion of sewing time during the operating cycle, while enabling the operator to arrange at the same time an associated second machine for sewing.

This and further objects which will be apparent from the ensuing detailed description are attained by the sewing machine in accordance with the teachings cf the accompanying claims.

The invention will be more apparent on reading the detailed description of a preferred embodiment thereof given hereinafter by way of non-limiting example and illustrated on the accompanying drawings, on which: Figure 1 is a schematic front view of the machine of the invention; Figure 2 is a schematic side view of said machine; Figure 3 is a schematic section on the line A-A of Figure 1; Figure 4 is a schematic partial section on the line B-B of Figure 1; Figure 5 is a schematic partial section on the line C-C of Figure 1; Figure 6 is a schematic detailed view from above, but with the sewing machine omitted, relative to the carriage which carries the sewing machine, the fabric drive members and the members for uncurling the fabric ends.

With reference to the figures, the machine 1 of the invention illustrated therein is associated with a conventional lap folder 2, the purpose of which is to unwind the tubular fabric T from a roll 2 positioned in a conventional cradle 4 and to discharge it, folded into laps, into a bin 5.

The machine of the invention is interposed between the cradle 4 and lap folder 2 and comprises a support structure which in this embodiment is an additional part of the support structure of the lap folder 2. Said support structure comprises legs 6,7 and a- main cross-member 8 supported by the legs 7, between which it

extends. The cross-member comprises on both its inner side and outer side a rectilinear guide 9 parallel to the axis of the cross-member. On the two parallel guides, which are positioned at the same height, there are supported two carriages indicated overall by 10 and 11.

The two carriages 10,11 are connected to a transmission element 12 (for example a belt or chain) passing about an idle return wheel 13 and a driven wheel 14.

The two said wheels are associated with tensioning devices 15 and are supported by the cross-member 8, the driven wheel 14 being driven by a geared motor unit 16 also supported by the cross- member 8.

The two carriages 10,11 are connected in known manner to the upper portion and, respectively, the lower portion of the belt or chain 12 to enable them to be driven simultaneously by the geared motor unit 16 towards the centre or towards the outside, so varying the distance between them, this being an essential condition for sewing tubular fabrics of different diameter.

The carriage 10 carries a usual sewing and trimming machine 17 together with the conventional devices relative to its operation.

On the said carriage 10 there are provided two parallel pulleys, one of which is driven by an electric motor 20A (see Figure 4).

The axes of these pulleys are parallel and are contained within the same vertical plane. On the carriage 10 there are also mounted a pair of selvedge uncurlers 20,21 (Figure 5) of helical screw type which, by operating under adjustable pressure directly on the fabric T, uncurl any curled edges and maintain their tension constant in front of the sewing machine 17.

More specifically, as can be seen in Figures 4,5 and 6, both the sewing machine 17 (with relative motor) and the selvedge uncurling members 20,21 (with relative motor 25, which operates them via a belt transmission 25A) are mounted on a slide 22 which, under the

action of a pneumatic cylinder 70, can slide in a direction perpendicular to the cross-member 8 along guides 23 provided on the horizontal flat part of the support structure 24 for the carriage 10.

The screws of the two uncurling members 20,21 are opposite handed and are linked to the motor in such a manner as to rotate in opposite directions. Motion is transmitted to the upper uncurling member 20 via a joint 26, for example a universal joint, as this member is mounted in a support 27 which can be rotated about a horizontal axis (away from and towards the other uncurling member 21) under the action of a pneumatic cylinder 28 carried by said structural part 24.

The structural part 24 (see Figure 4) supports an idle presser roller 29 via an arm 30 hinged at 31 to an upright rigid with the part 24. This presser roller is movable away from and towards the driven pulley 19 under the control of a pneumatic cylinder. The motor 21A also operates this roller 29 via an articulated joint 33, for example a universal joint.

The carriage 11 supports two idle pulleys 34,35 with horizontal axes contained in the same vertical plane.

An endless belt 36 passes about the two pairs of pulleys 18,19, 34,35 (Figure 1). It is interchangeable on the basis of the length of the circumference of the tubular fabric, its purpose being both to rotate the ends of the fabric T and to support their upper part.

The operation is as follows.

With the machine at rest (and the slide 22 retracted) the operator reverses the rear end TC of the lap-folded piece T1 and places it over the belt 36 (see Figure 2) so that it embraces the belt entirely, then over that end he places the front end TT (without- however reversing it) of the next tubular piece present on the

roll 3.

A quantity of fabric sufficient to allow trimming and sewing is left projecting beyond the belt 36, and the projecting fabric is inserted between the two selvedge uncurling members 20,21 (the member 20 is raised into the position shown by dashed lines in Figure 5). This insertion causes a microswitch 50 to operate, resulting in: a) the lowering of the upper uncurling member 20 (by the pneumatic cylinder 28), b) the rotation of the two uncurling members 20,21 by the motor 25 (see Figure 5) to hence uncurl and stretch the ends TT and TC lying superposed in front of the sewing machine 17, c) advancement of the slide 22 into its operating position (under the action of the cylinder 70). After a predetermined time the electronic control circuit with which the machine is provided lowers the presser roller 29 (by means of the cylinder 32), and the motor 20A of the conveyor belt 36 is operated simultaneously with the sewing machine 17. The two superposed ends are hence made to advance below the sewing machine, which trims and sews them along their entire circumference.

A proximity sensor 60 senses the presence of an element (for example a metal bar 61) inserted into the belt 36, to halt the machine on completion of one revolution of the belt.

A second sensor (optional and not shown) can be used if the sewing operation has to be interrupted along a certain length in order to create a"hole"to allow easy outflow of the liquid of the bath in which the fabric is to be subsequently (ie after lap-folding) treated.

With stoppage of the sewing machine 17 the conveyor belt 36 and the the uncurling members 20,21 are halted and the uncurling member 20 and presser 29 are raised, and the slide-22 withdrawn.

The sewn fabric is discharged from the machine of the invention by the action of the lap folder (or another unwinding device provided

for this purpose and not forming part of the invention).

A sensor 100 halts the lap folder or other unwinding device when the roll of fabric has been completely unwound, and possibly informs the operator of this event to enable him to load a new roll and again commence the described operations.

Various modifications fall within the scope of the invention. For example the number of pulleys 18,19; 34,35 of each carriage can be greater than two. In certain cases the conveyor belt 36 can be dispensed with by making one of the pulleys (34,35) of the carriage (11) driven, or by associating it with a presser similar to the presser 29. An endless belt or a sort of track could extend about the pulleys. The belt 36 could be replaced by straps.