The present invention relates to the textile industry field, and particularly refers to a machine for carrying out sewing lines on multilayer cloths to be quilted.

More specifically, the invention refers to quilting machine for mattress panels.

It is known that traditional mattress panels are realised by sewing coupling of two or more tissue layers between which a padding is provided, comprised of wadding, polyester, or any other natural and/r synthetic material suitable to the specific aim (it is also known that said panels are the separation element between the user body and the "suspension portion", comprising springs or, as an alternative, foam material, such as latex or polyurethane).

Thus, sewing does not only carry out an aesthetic function, but also ensures connection between different layers comprising the mattress panel.

Quilting machine are known since many time in order to realise said panels, connected with an apparatus permitting first unwinding single tissue and padding bands from relevant reels and thus juxtaposing them to realise a multilayer cloth, which is advanced, by suitable pulling devices, along the frame. Said frame is provided with means for tensioning said multilayer cloth, necessary for a proper quilting by sewing machines. Usually, said sewing machines, controlled to make quilting lines according to a set design, move transversely along the bridge on which they are mounted, the latter being able to longitudinally move along the frame of the same quitting machine.

It is known that often such an operation is very expensive and long when manufacturing mattress panels.

Object of the present invention is that of at least obviating to the above problem, thus reducing manufacturing time for mattress panels even ensuring the same level of aesthetic and functional quality.

Further object of the present invention is that of providing a quilting machine which is simple, reliable and cheap.

It is therefore specific object of the present invention a quilting machine suitable to quilt a multilayer sheet of the type comprising:

- a frame, on which said sheet to be quilted is laid and advanced according to a set longitudinal or advancement direction; - grasping members suitable to block and transversely and longitudinally tensioning said sheet to be quilted on said frame,

- at least a track,

- a first bridge, movable along said track according to a longitudinal direction, leftward or rightward, said bridge being suitable to bring one or more sewing machines suitable to quilt said sheet, said one or more sewing machines translating on said transverse direction, perpendicular to said longitudinal direction, said quilting machine comprising a second bridge, also said second bridge:

- longitudinally translating along said track according to said longitudinal direction,

- being suitable to bring one or more sewing machines that can translate on said bridge according to said transverse direction.

According to the invention, first and second bridge can move at the same time along said track, moving substantially respectively from the rear beam and from the front beam of said frame up to its half line, both bridges being apt to quilt at the same time two consecutive portions of said sheet.

It is preferred that said quilting machine is provided with stop means suitable to prevent hitting between said bridges in correspondence of centreline of said frame.

According to the invention, two bridges are moved longitudinally along the track by motion means, respectively first motion means for the first bridge and second motion means for the second bridge, and said stop means can be placed on at least one of said bridges and/or on at least one of said motion means.

Said stop means can be of the optical and/or mechanical type.

Optical stop means can comprise at least a sensor suitable to detect distance between the two bridges or between the motion means.

As an alternative, optical stop m eans ca n comprise a laser emitter, provided on one of said bridges or on one of said motion means, and a laser receiver, provided on the other bridge, or on the other motion means, said receiver being suitable to cooperate with said emitter in order to detect distance between the two bridges or between said first and second motion means.

Mechanical stop means can comprise a switch, provided on one of said bridges or on one of said motion means, and a rod, provided on the other bridge or on the other motion means, said rod having a set length, corresponding to the minimum distance between the two bridges, said rod being suitable to cooperate with said switch so that, when said two bridges, translating contemporaneously along said track, reach their minimum distance, said rod actuate said switch, blocking the movement of said bridges.

Both first and second motion means comprise a pair of carriages.

Still according to the invention, two bridges can translate contemporaneously along said track, substantially moving from rear beam and from front beam of said frame up to be close its centreline.

Particularly, said first bridge or said second bridge can prosecute its motion beyond centreline, and said additional movement can be at least equal to the zone straddling said centreline not covered by said bridges, and both said bridges cooperate to quilt the same portion of said sheet.

Furthermore, according to the invention, said grasping members can comprise:

- section bars hinged on longitudinal bars of said frame, and that can be actuated and closed against said longitudinal bars, said section bars ensuring tightening of lateral edges of said sheet and its transverse tensioning; and

A section bar that can be actuated and closed against rear beam of said frame, said section bar and said motor and pressure roll pair ensuring longitudinally blocking and tensioning said sheet to be quilted.

Still according to the invention, sheet parts quilted by quilting machine can be mattress panels.

Advantageously, quilting machine can provide, downward, a reservoir suitable to temporaneously store said quilted sheet, said reservoir comprising idle upper rolls, mounted on fixed hubs, and lower rolls, opposed to said upper rolls and mounted on a slide that can translate vertically along suitable guides, said sheet wounding alternatively on said upper and lower rolls, after its quilting, so as to permit quilting said sheet at the same time and advancing the quilted sheet toward a cutting apparatus.

Furthermore, quilting machine can be connected to: . upward, a sheet supplying apparatus, said supplying apparatus comprising at least reels on which tissue and/or padding bands comprising said sheet are wound, and at least a roll suitable to approach and overlap said tissue and/or padding bands to realise said sheet;

- downward, a cutting apparatus, said cutting apparatus comprising cutters for transverse cutting and longitudinal trimming of said sheet afters its quilting;

- a pulling group, placed between said quilting machine and said cutting apparatus, said pulling group comprising said motor and pressure roll pair, co-acting tangentially to also behave as dragging and advancement device for said sheet to be quilted, along said advancement direction, and said reservoir, downward said motor and pressure roll pair.

It is further object of the present invention, a quilting station, comprising at least a quilting machine, at least a supplying apparatus, at least a pulling group and at least a cutting apparatus according to the above.

Further features of the present invention will be more evident from the following specification of some preferred embodiments, corresponding to the claims, and shown, for exemplificative and not limitative purposes, in the enclosed drawings, wherein:

figure 1 shows a lateral view of the quilting station for mattress panels according to the invention;

figure 2 is a perspective view of quilting machine of quilting station of figure 1 , according to the invention;

figures 3 and 4 respectively show a perspective view of cutting apparatus and a lateral view of pulling group of quilting station of figure 1 according to the invention;

figure 5 shows a particular of quilting machine of figure 1 , relevant to optical stop means comprising a sensor;

figure 6 shows a particular of quilting machine of figure 1, relevant to optical stop means comprising a laser emitter and a laser receiver;

figure 7 shows a particular of quilting machine of figure 1, relevant to mechanical stop means comprising a rod and a switch;

figure 8 shows a particular of quilting machine of figure 1 , relevant to optical stop means comprising a laser emitter and a laser receiver in combination with mechanical stop means comprising a rod and a switch.

The features of the invention will be now described making reference to the figures. Before describing the invention, it is useful underlining for sake of simplicity that reference will be made to a quilting station S for mattresses (see for example figure 1), although the same machines and apparatuses can be advantageously used for any other object requiring this kind of sewing operations (for example, quilts, blankets, downs, ecc).

Making reference to figure 1, by reference number 1 it is indicated quilting machine, according to the invention, of said quilting station S, while by reference numbers 2 and 3 they are indicated respectively "supplying apparatus" of tissue band and padding to be coupled by quilting and their "cutting and trimming apparatus" (in the following cutting apparatus), respectively upward and downward the quilting machine 1. A "pulling group" 4 for supplying and advancing according to direction A is placed between quilting machine 1 and cutting apparatus 3, along the quilting machine 1 , on bands to be quilted. From now on, reference will be made for specification of features and geometry of various components of the station S just to the advancement direction A of bands to be quilted.

Supplying apparatus 2 and cutting apparatus 3 are substantially standard, and thus well known to the skilled in the art, and thus will be not described in the following.

It is here sufficient saying that supplying apparatus 2 comprises reels 21, supported by a support 22, on which tissue and padding bands (not shown) are wound, to be coupled with at least one roll 23 by which said bands are approached and overlapped each other to realise a multilayer sheet; said sheet is dragged to the quilting machine 1 inlet by suitable means (as it will be better seen in the following, by a pair of motor 41 and pressure 42 rolls) of the pulling group 4 (see figure 4).

As already said, also cutting apparatus 3, useful for transverse cutting and longitudinal trimming of the multilayer sheet, is of known type.

Only for exemplificative, but not limitative, purposes, as shown in figure 3, said cutting apparatus can comprise a first rotating knife cutter 31 ,, that can translate along a guide 33 vertically extending between its flanks 34 (equivalent solution are obviously possible, such as, for example, a "guillotine" cutter), and a pair of second cutters 32, as well of the rotating knife type.

Said second cutters 32 substantially lie on a plane which is perpendicular to the plane of said first cutter 31 , and are mounted at the ends of an axis 35, with an inter-axis that can be adjusted in function of the wished width of the panel under operation.

Now, it is possible describing quilting machine 1 according to the invention.

As shown in figures 1 and 2, reference number 11 shows frame of the quilting machine, said frame 11 comprising four uprights 112, suitable to support a pair of transverse beams 113 and 114 and a pair of longitudinal bars 115.

Upper faces of said longitudinal bars 115 are flat and act as resting surface of lateral edges of the multilayer sheet supplied from supplying apparatus 2. Section bars 118 are further hinged on longitudinal bars 115, according to axes parallel to the sheet advancement direction A, so shaped to realise along with said longitudinal bars, grasping members of the lateral edges of the sheet. Section bars 118 are in fact operated and closed by linear actuators against relevant longitudinal bars 115, thus ensuring tightening and transverse tensioning of the sheet on frame 11.

A similar section bar 117, operated by actuators against rear beam 113 of said frame 11 , for tightening rear edge of the sheet, and pair of motor 41 and pressure 42 rolls of the pulling group 4, co-acting tangentially in order to tighten front edge of the same sheet (thus acting as grasping member besides as dragging device), instead ensure blocking and longitudinal tensioning of sheet to be quilted.

A track 116 extend between said longitudinal bars 115, for sliding of a first bridge 12 supporting one or more sewing machines 13, apt to quilt said sheet.

According to an important feature of the invention, quilting machine 1 comprises a second bridge 12', movable along said track 116, for supporting one or more sewing machines 13 suitable to quilt said sheet.

In the example shown in figure 2, said first 12 and second 12' bridges are respectively provided with two sewing machines 13.

Upper 121 and lower 122 beams of said bridges 12, 12' straddle on the sheet to be quilted laying plane when under tension, and respectively bear sewing head 131 and counter-head 132 (also known as crocher device) of said sewing machines 13.

Said first 12 and second 12' bridges longitudinally slide along track 116, according to X direction, by relevant motion means, first motion means for the first bridge 12 and second motion means for the second bridge 12'.

In the embodiment described, said first and second motion means respectively comprise a first pair of carriages 61 and a second pair of carriages 61". Said pairs of carriages are moved by suitable motorisation.

More particularly (as will be more evident from the following description), said bridges 12 and 12' can translate at the same time along said track 116, to respectively pass from lower beam 113 and from upper beam 114 substantially up to the centreline B-B (and/or vice versa), quilting, by said sewing machines 13, the sheet.

Making particular reference to figures 5 - 7, quilting machine comprises suitable stop means that can be of the optical and/or mechanical type, in order to prevent hitting between the bridges 12, 12'.

In a first example, shown in figure 5, said optical stop means comprise a sensor 50, provided aside one of said carriages 61', detecting distance from bridge 12 sliding on carriages 61.

In a second example, shown in figure 6, said stop means are of the optical type as well, and comprise a laser emitter, provided on carriage 61', sliding on the same section bar of track on which said carriage 61 slides, suitable to cooperate with said laser emitter 51 in order to detect distance between said carriages 61 and 61'.

In another example, shown in figure 7, said stop means are of the mechanical type and comprise a rod 53, on one of the carriages 61 , perpendicular with respect to the bridge 12, and a switch 54 for blocking the movement of the two bridges, provided on carriage 61', sliding on the same section bar along which carriage 61 on which rod is provided slides.

Rod has such a length that, when distance between first 12 and second 12' bridge corresponds to a minimum set distance, rod 53 interact and actuate switch 54, blocking movement between two bridges, preferably starting a movement according to an opposite direction. In a further example, shown in figure 8, it is provided the combination of optical means, comprising laser emitter 51 and laser receiver 52, and mechanical means described in the above.

In the specific example, cooperation between rod 53 and switch 54 realises a safety system, in case laser receiver 54 and/or laser emitter 52 are accidentally damaged, or in case emitter and receiver are no more optically aligned or do no more properly work.

Although not shown in the figures, said stop means can be provided on at least one of said bridges, or both on at least a carriage and a bridge.

By further motors and transmission 123 and guide 124 means, each sewing machine 13 is actuated according to direction Y perpendicular to direction X along which said bridges 12, 12' slide. Hitting of said sewing machines 13 is prevented by stop means (not shown) similar to those provided for bridges 12, 12'.

According to a preferred embodiment of the invention, both bridges 12, 12' are at the same time aimed to quilting two consecutive parts of the multilayer sheet, provided under tension on said frame 11 of the quilting machine 1 , so as to carry out at the same time, but independently each other, sewing of two mattresses panels.

In other words, combination of longitudinal displacement of bridges 12, 12' along track 116 and of transverse movement of sewing machines 13 along the same permits at the same time making, on different parts of the sheet, the desired quilting design.

Thus, by quilting machine 1 according to the invention manufacturing time is the half, with the same number of mattress panels to be realised.

Mattress panel working and realising station 8 is completed by pulling group 4 already mentioned in the above.

Motor roll 41 (controlled by motor 43 of figure 4) and pressure roll 42, of the pulling group 4 have been already described in the above, co-acting tangentially behaving as a tensioning and blocking member for the sheet during its quilting and as dragging device according to direction A.

Said pulling group 4, as shown in the preferred embodiment of figure 4, further comprises, downward said roll pair 41 , 42, a reservoir 44 for temporary storage of quilted sheet. In fact, reservoir 44 provides, as already known, a suitable number of upper 45 and lower 46 rolls, opposed each other, about which quilted sheet winds. More specifically, upper rolls 45 are idle rolls, mounted on fixed hubs, while lower rolls 46 are mounted on a slide 47 that can translate, controlled, vertically (particularly downward), by a motor 48 on suitable guides 49, permitting to the quilted sheet, maintained under a light tension, to accumulate within said reservoir 44. Number of upper rolls 45 and of lower rolls 46 and maximum stroke of slide 47 determine length of sheet that can be stored, to be sent to cutting apparatus 3 provided downward.

Reservoir 44 thus permit making quilting operation on multilayer sheet, blocking and putting under tension the same on frame 11 , and at the same time permitting longitudinal and transverse cutting, requiring a slow advancing.

While cutting operation is carried out, reservoir 44 is further able to absorb new quilted sheet parts within upward quilting machine 11.

Operation of station S, although easily understood from the above specification, can be summarised as follows.

Tissue and padding bands, after unwind from relevant reels 21 , are dragged and introduces by pulling group 4 within quilting machine 1 , said bands realising multilayer sheet to be subjected to quilting. Multilayer sheet already quilted is stored within reservoir 44.

Sheet just inserted into quilting machine 1 is then blocked on its frame 11, upward quilting machine 1 (reference is always to sheet advancement direction A) between section bar 117 and beam 113, downward, between motor 41 and pressure 42 rolls, suitable also to drag the same, and laterally between section bars 118 and corresponding longitudinal bars 115. By said grasping members 113-117, 115-119, 41- 42, sheet is further maintained transversely and longitudinally tight, easing quilting operation (e.g. it is prevented jamming of sewing machine 13 while moving).

With the sheet in this condition, combined displacement of bridges 12, 12' along direction X, and of the respective sewing machines 13 along direction Y, realises the contemporaneous quilting of two different consecutive zones.

While quilting operation goes on the different zones of the sheet under operation, sheet already sewed and stored within reservoir 44 of the pulling group 4 is gradually released, sending the same to the cutting apparatus 3 for longitudinal trimming and for transverse cutting.

By a single sewing operation it is thus obtained a pair of mattress panels with desired length and width.

Obviously, to be pushed from quilting machine 1 to the reservoir 44 (by motor 41 and pressure 42 roll pair) and to unwind new portions of bands to be coupled, quilted s heet will have to be released, at least upward and in correspondence of the lateral edges from grasping members 113-117, 115-118, 41-42.

It is well clear that many modifications of the quilting machine 1 according to the invention can be introduced by one skilled in the art, without departing from the scope of the invention, as well as it is clear that when practising the invention, various components described in the above can be replaced by technically equivalent elements.

For example, two bridges 12, 12', instead being used for quilting at the same time on the same multilayer sheet, two different mattress panels, they can cooperate for quilting a single panel.

In this case, according to a possible embodiment, two bridges 12, 12' approach (as for the preferred embodiment), quilting the single panel respectively from its front edges (close to the front beam 114 of the frame 11) and rear (close to the rear beam 113 of the same frame 11) up to its centreline where they are stopped thus preventing hitting.

As it can be understood, zone straddling said centreline is not suitably quilted, not being possible reaching the same by the two bridges 12, 12'.

According this solution, one of the two bridges 12, 12' during the sewing operation can prosecute its displacement up to passing the centreline, said additional displacement being at least equal to said not properly quilted zone (it is well clear that, in order to permit the above, the other one must be brought toward the front or rear edge of the sheet, at least in the same way).

In this situation, it is also possible a very simple alternative, according to which one of the two bridges 12 is substantially not operative in correspondence of the rear beam 113 or front beam 114 of frame 11, while the other one makes the whole quilting operation of the single panel.

In conclusion, by quilting machine 1 (and relevant operation station S) according to the invention, it is obtained the wished aim, i.e. possibility of reducing manufacturing time for mattress panels (with the same number of pieces to be manufactures, with small modification of the same quilting machine 1 , i.e. elongation of longitudinal bars 115 of the frame 11 and provision of an additional bridge 12', preferably equal to the first one, thus also not increasing too much costs.