Buffer device for matching the output speed of a lap of a spreading-lapping machine to the input speed of a device for processing the lap downstream of the spreading-lapping machine.

Description

The present invention relates to a buffer device for adapting the output speed of a lap from a crosslapper to synchronize it with the input speed of a further processing device for the lap, for example a needle loom or other consolidation device. The present invention also relates to an installation comprising a crosslapper, a further processing device, such as a needle loom or other consolidation device, and a buffer device of this kind. The present invention also relates to a crosslapper in which a buffer device of this kind is incorporated.

Traditionally, the output speed of a lap from a crosslapper, in particular the displacement speed of its output apron, is not constant and varies over time, in particular due to the fact that it slows down or stops each time the layering carriage arrives at the end of its movement and sets off in the opposite direction, these changes in direction being particularly noticeable during the production of laps with a low weight, for example less than 150 g/m², to prevent the appearance of defects at the edge of the lap. After leaving the crosslapper, the lap is traditionally sent to a further processing installation, for example a needle loom, and it is necessary to ensure that the lap enters the needle loom at a speed adapted to said needle loom, in particular at a constant speed.

FR2930563A1, submitted by the applicant, already discloses a buffer device of this kind arranged at the outlet of a crosslapper before a needle loom. Adapting the speed of the lap is in this case achieved by a vertical displacement of a belt supporting the lap, which has the effect of varying a useful length of the lap supported by the belt and thus adapting the displacement speed to that required at the inlet to the further processing device.

Although the device of the prior art enables the output speed of the crosslapper to be adapted, this device nevertheless has the disadvantage, due to its vertical back-and-forth movements, that it causes damage to the lap, while this, as it is still not consolidated, still has a fragile structure.

It would thus be desirable to have access to a buffer device for adapting the output speed of a crosslapper to an input speed, in particular a constant speed, of a further processing device, in particular a needle loom or other consolidation device, such that the lap is transferred from the crosslapper to the further processing device while still having a quality identical to the quality it had when leaving the crosslapper.

According to a first feature of the invention, an installation comprising:

• • a crosslapper comprising an output apron delivering a lap of fibers, in particular nonwoven, at the outlet, said lap being made up of a stack of webs arranged in a zigzag pattern by a back-and-forth movement of a layering carriage of the crosslapper, the speed of the output apron being a speed V1(t) that varies over time;
  • a further processing device arranged downstream of the crosslapper, and having an inlet belt that moves at a speed V2(t) which differs from the speed V1(t), in particular a constant speed V2(t); and
  • a buffer device for adapting the speed, arranged between the crosslapper and the further processing device,
  • is characterized in that the buffer device comprises a lower belt, in particular an endless belt, and an upper belt, in particular an endless belt, the path of the lower belt being such that the lap is turned, in particular through 180° or substantially through 180°, twice in succession in opposite directions, around two turning rollers, upstream and downstream respectively, the upper belt covering the lap by sandwiching said lap with the lower belt over at least one coverage zone extending over at least part of the zone of the belts extending between the two upstream and downstream turning rollers, in particular over the entire zone of the belts extending between the two upstream and downstream turning rollers, and, preferably also over at least part of the circumference of the upstream turning roller and/or part of the circumference of the downstream turning roller, and the axis of one of the two upstream or downstream rollers or both axes of both rollers, preferably the axis of the downstream roller only, is/are mounted such that they can move, in particular in translation, in particular along a rectilinear trajectory, in particular horizontal, to thus change the speed of an upstream portion of the lower belt, corresponding to the output speed V1(t) of the crosslapper, to a speed of a downstream portion of the lower belt corresponding to the input speed V2(t) of the further processing device, in particular the needle loom, in particular a constant speed V2(t) while the speed V1(t) varies over time, in particular in a periodic manner.

By enabling the lap of fibers passing through the buffer device to be turned by being sandwiched between the two upper and lower belts and by changing the speed by means of moving one of the turning rollers, it is possible to ensure that the lap remains well protected in the part of the device changing and adapting the displacement speed of the lower belt supporting said lap, and, in particular, it is possible to ensure that the lap is protected from any harmful actions as a result of drive or centrifugal forces associated with the back-and-forth movements required to achieve said compensation, and it is thus possible to obtain a lap at the inlet to the needle loom or consolidation installation or similar that has a quality that is as good as it was at the outlet from the crosslapper, all while being supplied to the needle loom at a speed adapted to said loom, in particular a constant speed.

Preferably, the two lower and upper belts are endless, in other words form a respective closed loop, and appropriate holding means are provided to keep the respective lengths of the two lower and upper belts constant, said holding means being synchronized with the movement or movements of the axis or axes of the upstream and/or downstream roller.

According to a preferred embodiment, the holding means comprise a lower holding roller around which the lower belt extends and an upper holding roller around which the upper belt extends, the two axes of the two rollers being such that they move with the axis of the movable upstream or downstream roller, in particular by being an integral part of a carriage of which the axis of the upstream or downstream roller is also an integral part.

Preferably, the carriage is able to move along two rectilinear rails.

In particular, the two rectilinear rails are oriented in a horizontal direction.

Preferably, the lower belt is air-permeable and the upper belt is air-impermeable.

The present invention also relates to a machine with the ability to form the buffer device of the installation according to the invention according to a second feature thereof.

In particular, the buffer device for adapting the speed comprises a lower belt, in particular an endless belt, and an upper belt, in particular an endless belt, the path of the lower belt being such that it is turned, in particular through 180° or substantially through 180°, twice in succession in opposite directions, around two turning rollers, upstream and downstream respectively, the upper belt covering the lower belt over at least one coverage zone extending over at least part of the zone of the belts extending between the two upstream and downstream turning rollers, in particular over the entire zone of the belts extending between the two upstream and downstream turning rollers, and preferably also over at least part of the circumference of the upstream turning roller and/or part of the circumference of the downstream turning roller, and the axis of one of the upstream or downstream rollers or both axes of both rollers, preferably the axis of the downstream roller only, is/are mounted such that it/they can move, in particular in translation, in particular along a rectilinear trajectory, in particular horizontal, to thus change the speed V1(t) of an upstream portion of the lower belt to a speed V2(t) of a downstream portion of the lower belt that is different from V1(t), in particular V2(t) being constant while V1(t) varies as a function of time, in particular in a periodic manner.

The present invention also relates to a crosslapper in which means having the buffer function of the buffer device according to the invention are incorporated.

Thus, according to a third feature of the invention, a crosslapper, in particular arranged at the outlet of a carding device producing a web of fibers, in particular nonwoven fibers, is as defined in claim 1, the dependent claims defining improvements and embodiments thereof.

Furthermore, in a favorable manner, a crosslapper may comprise a front belt, in particular an endless belt, carrying the web of fibers in the crosslapper to an infeed or accumulator carriage, a rear carriage carrying the accumulated web to a layering carriage and an apron on which the layering carriage deposits the web accumulated by the accumulator carriage alternately on the bias in one direction and in the other direction to form a lap moving at a speed V1(t) that varies as a function of time, in particular in a periodic manner, the crosslapper also comprising an output belt by which the lap leaves the crosslapper at a speed V2(t) that is different from the speed V1(t), in particular at a constant speed, the lap undergoing, between the apron and the output belt, at least one turn around a roller, the axis of which is mounted such that it can move, in particular in translation, in particular in the horizontal direction, and, at least after the turn, the lap is sandwiched between an air-permeable belt and an air-impermeable belt.

According to a first favorable embodiment, the output belt is air-permeable, the apron is an upper strand of an air-impermeable endless belt and the turn is carried out at one of the rollers around which the endless belt extends.

According to another favorable embodiment, an air-permeable endless intermediate belt is provided between the apron and the output belt and the turn of the lap is carried out around one of the rollers around which the endless intermediate belt extends and, preferably, the apron and the outlet belt form part of the same endless belt and the arrangement is such that the lap is sandwiched before the turn, during the turn and after the turn between the endless intermediate belt and said same endless belt, preferably air-impermeable.

By way of example, preferred embodiments of the invention will now be described with reference to the drawings in which:

FIG. 1 is a side view of an installation according to the invention, the crosslapper being on the right-hand side of the figure, the compensation device being in the center and the further processing device, which is located to the left of the figure, not being shown;

FIG. 2 is a large-scale view of the compensation machine of the installation in FIG. 1;

FIG. 3 is a schematic side view of part of a crosslapper according to an embodiment of the invention;

FIG. 4 is a schematic side view of part of a crosslapper according to another embodiment of the invention;

FIG. 5 is a schematic side view of part of a crosslapper according to yet another embodiment of the invention;

FIG. 6 is a schematic side view, partially cutaway, of the crosslapper from FIG. 3;

FIG. 7 is a schematic side view, partially cutaway, of the crosslapper from FIG. 4; and

FIG. 8 is a schematic side view, partially cutaway, of the crosslapper from FIG. 5.

FIGS. 1 and 2 show an embodiment of an installation according to the invention. This comprises a crosslapper 1, delivering, via an output apron 2, a lap of nonwoven fibers consisting of a stack of webs of fibers deposited successively on the bias with respect to the longitudinal displacement direction of the apron 2 by an accumulator carriage (not visible in the figure) of the crosslapper.

Downstream of the crosslapper 1 and its output apron 2, a compensation machine 3 is provided, said machine receiving the lap of fibers from the apron 2 on an upstream portion 4.1 of an air-permeable lower belt 4, which transports the lap of fibers to a downstream output portion 4.2 of the input belt 4 to feed a further processing device which may, for example, be a needle loom or, as shown in FIG. 1, a tenter followed by a needle loom (not visible in the figure).

The lower belt 4 is endless and extends around rollers 6.1, 6.2, 6.3, 6.4, 6.5 and 6.6. Of these rollers 6.1 to 6.6, two rollers, 6.3 and 6.6 respectively, are driven by lower 7 and upper 8 motors.

The lower belt 4 comprises a first substantially horizontal upstream portion extending between the roller 6.1, which is closest to the crosslapper or downstream roller 6.1, to a first upstream roller 6.6, turning through 180°, around which it performs a half-turn through 180°, then a portion extending to a downstream lower turning roller 6.5 where it performs a half-turn through 180° in the opposite direction to the half-turn performed at the upstream turning roller to thus turn the lap in the same direction in which it entered the upstream inlet portion of the lower belt 4 to a lower portion 4.2 extending to a downstream end roller 6.4. The input belt 4 then comprises a lower portion between the downstream end roller 6.4 and the roller 6.3 driven by the motor 7, then returns along a portion extending between the roller 6.3 and the roller 6.2, where it undergoes a turn to return to the roller 6.1.

The lap of fibers leaving the apron 2 is supported by the lower belt 4 on the first and third portion or upstream input portion and end downstream output portion, and around the two upstream and downstream turning rollers 6.6 and 6.5.

The device also comprises an air-impermeable upper belt 9 which is endless and is driven around rollers 6.7, 6.8, 6.9 and 6.10, as well as around rollers 6.5 and 6.6. The upper belt 9 covers the lap and sandwiches it with the belt 4 on part of the first portion of the belt 4, a half-circumference of the upstream turning roller 6.6, the intermediate portion between the two upstream 6.6 and downstream 6.5 turning rollers, a half-circumference of the downstream turning roller 6.5 and part of the downstream end portion 5 of the belt 4.

The downstream turning roller 6.5 is mounted such that its axis is able to move along rails 12 in a horizontal direction. The speed of the motor 8 of the upstream turning roller 6.6 is controlled such that the input portion of the belt 4 has the same speed as that of the apron 2 of the crosslapper 1. The output speed of the motor 7 driving the downstream roller 6.3 is controlled to achieve a constant speed corresponding to the speed of the input belt of the further processing device, for example the needle loom.

Thus, the two motors 7 and 8 each rotate at different speeds corresponding to the speed of the output belt 2 of the crosslapper in one case and in the other case 7 to the input speed of the further processing device, in particular the needle loom. The difference between these speeds causes a variation in the length of the portion of the lower 4 and upper 9 belts which extends between the rollers 6.5 and 6.6, and this variation is compensated by the movement of the axes of the rollers 6.5 and 6.2 for the lower belt 4 and by the movement of the axes of the rollers 6.5 and 6.10 for the upper belt 9, the other axes of the rollers being fixed (the rollers are virtually static, not being moved in translation, but merely in rotation in relation to their respective axis)).

FIGS. 3 and 6 show a crosslapper according to the invention, in which a compensation device is incorporated. The crosslapper in FIGS. 3 and 6 comprises a front belt 303′, in particular an endless belt, carrying the web of fibers in the crosslapper to an infeed or accumulator carriage, a rear belt 302′ carrying the accumulated web to a crosslapper or removal carriage and an apron 100′ on which the layering carriage deposits the web accumulated by the accumulator carriage alternately on the bias in one direction and in the other direction to form a lap moving at a speed V1(t) that varies as a function of time, in particular in a periodic manner. The crosslapper also comprises an output belt by which the lap leaves at a speed V2(t) that is different to the speed V1(t), in particular at a constant speed. The crosslapper comprises an apron 100′ on an upper strand 2′ of which the web is deposited in a plurality of layers in a zigzag pattern by the removal carriage to form a lap N, the apron 100′ being driven around four rollers 3.1′, 3.2′, 3.3′ and 3.4′, at least one of which is a motor. An air-permeable endless belt forms an output belt 200′ of the crosslapper on an upper strand 20′ of which the lap leaves the crosslapper. This endless output belt 200′ is shown in a schematic manner and is driven in the same manner by rollers which rotate at a constant speed or synchronized with the further processing device. The lap N undergoes a turn around the roller 3.2′ to be sandwiched between a lower strand, opposite the upper strand 2′, of the air-impermeable apron and the upper strand 20′ of the output belt.

The axes of the two upper rollers 3.1′ and 3.4′ are mounted such that they are fixed whereas the axes of the rollers 3.2′ and 3.3′ are mounted such that they can move in a horizontal translationally fixed manner in a back-and-forth movement to thus adapt the displacement speed of the lap passing from the strand 2′, which has a speed that varies as a function of time, to the strand 20′, which has a speed, in particular constant, equal to the speed of the input belt of the further processing device. During the back-and-forth movement of the rollers 3.2′ and 3.3′, the endless belt forming the apron 100′ maintains a constant overall length.

FIGS. 4 and 7 show another embodiment. The crosslapper in FIGS. 4 and 7 comprises a front belt 303″, in particular an endless belt, carrying the web of fibers in the crosslapper to an infeed or accumulator carriage, a rear belt 302″ carrying the accumulated web to a crosslapper or removal carriage and an apron 100′ on which the layering carriage deposits the web accumulated by the accumulator carriage alternately on the bias in one direction and in the other direction to form a lap moving at a speed V1(t) that varies as a function of time, in particular in a periodic manner. The crosslapper also comprises an output belt by which the lap leaves at a speed V2(t) that is different to the speed V1(t), in particular at a constant speed. The upper strand 2″ of the apron 100″ in the form of an air-impermeable endless belt is driven around rollers 3.1″, 3.2″, 3.3″ and 3.4″ with fixed axes, at least one of which is a motor. An air-permeable intermediate endless belt 30″, arranged between the apron 100″ and a strand 20″ of an output belt 200″ is provided, the intermediate belt 30″ being driven between two rollers 4.1″ and 4.2″, at least one of which is preferably a motor. The axes of the rollers 4.1″ and 4.2″ are mounted such that they can move in a translationally fixed manner in the horizontal direction in a back-and-forth movement to thus adapt the displacement speed of the lap passing from the upper strand 2″, which has a speed that varies as a function of time, to the upper strand 20″ of the output belt, which has a speed, in particular constant, equal to the speed of the input belt of the further processing device.

In this embodiment, the lap N is subjected to a turn around the roller 4.1″. Before the turn, it is sandwiched between a lower strand of the apron, which is turned in the opposite direction to the upper strand 2″, and an upper strand of the intermediate belt 30″. After the turn, it is sandwiched between the upper strand 20″ of the output belt and a lower strand of the intermediate belt 30″. The lower strand of the intermediate belt 30″ is turned in the opposite direction to the upper strand of the intermediate belt 30″. During the back-and-forth movement of the rollers 4.1′ and 4.2′, the endless belt forming the intermediate belt maintains a constant overall length.

Finally, FIGS. 5 and 8 show a third embodiment. The crosslapper in FIGS. 5 and 8 comprises a front belt 303′″, in particular an endless belt, carrying the web of fibers in the crosslapper to an infeed or accumulator carriage, a rear belt 302′″ carrying the accumulated web to a layering 304′″ or removal carriage and an apron 100′″ on which the layering carriage 304′″ deposits the web accumulated by the accumulator carriage 301′″ alternately on the bias in one direction and in the other direction to form a lap moving at a speed V1(t) that varies as a function of time, in particular in a periodic manner. The crosslapper also comprises an output belt (which, in this embodiment, is part of the apron 100′″) by which the lap leaves at a speed V2(t) that is different to the speed V1(t), in particular at a constant speed. An upper strand 2′″ of an apron 100′″ in the form of an air-impermeable endless belt extends around rollers 3.1′″ to 3.7′″, the upper strand 2′″, on which the lap N is deposited by the layering carriage, extends between two upper rollers 3.1′″ and 3.4′″. The lap N undergoes a first turn around the upper turning roller 3.3′″ and is then sandwiched between an intermediate upper strand, which is turned in the opposite direction to the upper strand 2′″ of the apron, which extends between the upper turning roller 3.3′″ and a lower turning roller 3.7′″, and an upper strand of an endless intermediate belt 30′″ which extends around the roller 3.7′″ and a roller 3.8′″. The lap then undergoes a second turn through 180° around the lower turning roller 3.7′″ in an opposite direction to the first turn, to then be supported by a lower strand 20″′ of the apron output belt extending between the turning roller 3.7′″ and a lower roller 3.6′″ at the downstream end, the lap leaving the crosslapper on the lower output strand 20″′.

The upper strand of the intermediate belt 30′″ sandwiches the lap with the intermediate upper strand of the apron 2′″ between the two turning rollers, 3.3′″ and 3.7′″ respectively, then the lower strand of the intermediate belt 30′″ sandwiches the lap with the lower strand 20′″ of the output belt of the apron between the turning roller 3.7″′ and a roller 3.8′″ at the downstream end of the intermediate belt 30′″. The intermediate belt 30′″ is air-permeable and is driven around the two rollers 3.7′″ and 3.8′″, which are mounted such that they can move in a translationally fixed manner in a back-and-forth movement such that their axes move in translation to adapt the displacement speed of the lap passing from the upper strand 2″ of the apron 200″, which has a speed that varies as a function of time, to the lower strand 20′″ of the apron 200′″, which has a speed, in particular constant, equal to the speed of the input belt of the further processing device.

The lap is sandwiched between the apron and the intermediate belt 30′″ before the second turn, during the second turn, around the roller 3.7′″ and after the second turn, and is thus well protected from the harmful effects of drive and/or centrifugal forces associated with displacements of the rollers 3.7′″ and 3.8′″ in translation and in rotation.

In the embodiments in FIGS. 4 and 5, it is conceivable that the intermediate belts, 30″ and 30′″ respectively, could be turned in the opposite direction so that the lap can be turned or not be turned as a function of the thickness of the lap. If there is no need for the lap to be turned, in particular in the case of very thick laps, for example in excess of 150 mm, the belts 30″ and 30′″ are turned in the opposite direction to that described in the figures and the lap is deposited directly on the strand 20″, or 20′″ respectively, of the output belt, after cascading over the rollers 3.3″ and 4.2″ respectively in the case of FIG. 4 and the rollers 3.3′″ and 3.8′″ in the case of FIG. 5.

In the embodiment in FIG. 3, it is conceivable to use two outlets, one on the right as shown, in particular for laps which are not very thick, for example which are less than or equal to 150 mm thick, and an outlet directly to the left without passing beneath the apron, in the case of thick laps, in particular those which are between 300 and 500 mm thick.

FIGS. 6 to 8 are partially cutaway to show the input and output belts and the infeed and removal carriages.