TECHNICAL FIELD

The present invention refers to a needle plate machine to consolidate by needling a fleece or web of fibres, in particular non-woven, comprising at least one needle plate, in front of which the fleece or web of fibres passes while moving forwards in the machine or MD direction, and a drive system configured to impart to at least one column integrated with the at least one needle plate and/or needles a to and fro motion in a direction perpendicular or essentially perpendicular to the plane of the mat or fabric so that the needles traverse the sheet or layer of fibres in an elliptical path first in one direction and then the other.

BACKGROUND

A needle plate machine of this type is known, for example from EP-A1-1736586 in the name of the applicant. The needle plate is connected to a rod or column that extends along a longitudinal axis and passes through the wall of an intermediate housing sliding through a guide pot with a motion both vertical and in the direction MD thereby giving the needles an elliptical motion, the pot being arranged so that it can pivot with respect to an axis extending in the direction CD (that is to say perpendicular to both the vertical direction and the direction MD).

This needling device of the prior art has the advantage of being able to be contained for the most part, namely the greater part of the column and the system for driving the column, in a sealed housing providing lubrication for the various parts and mechanical linkages to ensure increased life and reliability of the installation.

This needling device however has the problem of being a complex structure, requiring, in particular, means for providing a phase shift between the two cam shafts that drive the column to give it an elliptical motion.

A needling device with the same advantage of being able to be contained in a sealed housing providing good lubrication of the various drive components of the column, but while having a more compact, less complex structure is desirable.

A needling device is also known from FR-A1-2800396 comprising a needle plate, a column connected to the needle plate, a driving system configured to impart an elliptical to and fro motion to the column, a housing that contains a part of the column, a part of the drive system and a sleeve arranged in an opening in the housing, the column passing through the housing through the sleeve. In this complex device, the housing is not sealed and parts of the drive system, namely those designed to impart a transverse motion in the direction MD are outside the housing.

SUMMARY OF THE INVENTION

According to the invention, a device to consolidate a fleece or web of fibres, in particular non-woven, by needling is as defined in claim1.

According to the invention, a less complex system than that of the prior art is thereby obtained, in particular from a mechanical point of view, which is also more compact. In particular, it is no longer necessary to provide phase shift between two cam shafts. At the same time, the possibility of integrating the whole drive system in a sealed housing is retained and even enhanced, providing lubrication of the various mechanical components thereby ensuring long life and reliability of the installation.

Improvements and beneficial methods of implementation are defined in the claims below.

According to one beneficial method of implementation, the transverse drive system comprises a control device which in itself is an invention independent of the invention described above, but which can be combined with it, which includes: a drive rod coupled to the needles and/or the needle plate and/or to a component connected to the needle plate and/or to an oscillating pot to give them a to and fro motion in a direction essentially parallel to the direction MD or parallel to the direction MD, a cam shaft and a rod, the cam shaft driving the rod round in one axis of rotation, in particular in the direction CD perpendicular to the direction MD and to the vertical direction, and a rod connected to the tie-rod by means of a part forming an intermediate lever, comprising a single part or several parts not hinged together, pivoting with respect to a pivot pin, in particular parallel to the rotation pin of the cam shaft, the lever being hinged firstly directly to the rod, in particular in a direction parallel to the pivot pin and spaced apart from it, and secondly directly to the drive rod, in particular at a point spaced apart from the pivot pin to impart to the latter the to and fro motion in the direction MD.

Preferably, the control device includes means for adjusting the stroke of the to and fro motion of the drive rod.

In particular, the adjustment system adjusts the distance between the pivoting axis of the lever and the drive rod and/or the distance between the pivot pin of the lever and the rod.

According to a preferred method of implementation, the adjustment system comprises a slider connected to the drive rod or the pivot pin of the lever or of the hinge pin of the rod to the lever, the slider and the lever being arranged to enable the slider to slide in relation to the lever between several positions, and means for locking the slider to the lever in each of the said several positions.

According to a highly favourable method of implementation, the adjustment system comprises a guide slot in which the slider can slide between two extreme positions, in particular a high position in which the drive rod is located level with the pivot pin and a low position in which the drive rod is at its maximum distance from the pivot pin which the slider is connected to the lever, thereby enabling adjustment of the amplitude of the to and fro motion of the rod, in particular between zero amplitude (rod stationary) and maximum amplitude.

According to a preferred method of implementation, the means for fixing the position of the slider in the slot comprises an adjusting rod connected to an adjusting tie-rod, the adjusting tie-rod being hinged to an auxiliary adjustment cam shaft, rotating the auxiliary adjustment shaft enabling the position of the slider in the slot to be adjusted and locked.

According to another favourable method of implementation, the means for fixing the position of the slider in the slot comprise an adjusting rod connected to a spiral cam comprising a disk driven round by an auxiliary adjustment shaft with a spiral slot along which the adjustment rod can move.

According to yet another favourable variant, the system for fixing the position of the slider in the slot comprises an adjusting rod connected to an adjusting tie-rod driven by an actuator, permitting linear motion of the adjusting tie-rod, the adjusting tie-rod pivoting with respect to the axis of the adjusting rod.

