Roller leather finishing machine

Abstract

The present invention relates to a spreading machine for roller leather finishing. The machine includes a drawing cylinder and an engraved spreading cylinder. The drawing cylinder acts as a driving roller for a rubber conveyor belt wound between the driving roller and an idle roller. The drawing cylinder has a conveying surface and a rubber layer. In each operating configuration, the conveying surface of the rubber conveyor belt is tangent to the engraved spreading cylinder in a point of tangency (P), and the idle roller has a leather-detachment roller having a diameter within the range of 10 and 80 mm.

Claims

1. A reverse roller leather finishing machine, comprising a drawing cylinder and an engraved spreading cylinder, the drawing cylinder acting as a driving roller for a rubber conveyor belt wound between the driving roller and an idle roller and having a conveying surface, the drawing cylinder comprising a rubber layer, configured such that in each operating configuration, the conveying surface of the rubber conveyor belt is tangent to the engraved spreading cylinder in a point of tangency (P), wherein said idle roller comprises a leather-detachment roller having a diameter within a range of 10 and 80 mm.

2. The machine according to claim 1, wherein said rubber layer has a hardness within the range of 15 and 35 shore.

3. The machine according to claim 1, wherein said rubber layer has a thickness within the range of 10 and 30 mm.

4. The machine according to claim 1, wherein said rubber conveyor belt has a hardness within the range of 20 and 25 shore.

5. The machine according to claim 1, wherein said rubber conveyor belt has a thickness lower than 10 mm.

6. The machine according to claim 1, further comprising a mechanism for adjusting a distance (D) between the driving roller and the rubber conveyor belt, measured along a direction that joins the point of tangency (P) of the engraved spreading cylinder with the rubber conveyor belt and a centre of the engraved spreading cylinder, said mechanism allowing a corresponding translation of the point of tangency (P) along a longitudinal direction of the rubber conveyor belt.

7. The machine according to claim 6, wherein said distance (D) is between 0 and 5 mm.

8. The machine according to claim 6, wherein said mechanism comprises an intermediate idler roller, arranged between said driving roller and said leather-detachment roller, whose rotation axis can be translated between two predefined positions along a direction (V) substantially orthogonal to the conveying surface of the rubber conveyor belt.

9. The machine according to claim 6, wherein said mechanism comprises a system for translating a rotation axis of the engraved spreading cylinder along a direction (V).

10. The machine according to claim 1, wherein said leather-detachment roller comprises a plurality of rollers arranged axially, with their axis according to a transverse direction (T) of the rubber conveyor belt.

11. The machine according to claim 5, wherein said rubber conveyor belt has a thickness lower than 8 mm.

Description

BRIEF DESCRIPTION OF FIGURES

(1) Hereinafter in this description the drawings shown in the enclosed figures will be referred to, wherein:

(2) FIG. 1 is an overall schematic view of a machine according to the present invention in a first operating configuration;

(3) FIG. 2 is a detailed view of the contact area between the spreading roller and the underlying contrast and/or transportation system under the first operating condition;

(4) FIG. 3 is an overall schematic view of a machine according to the present invention under the second operating condition;

(5) FIG. 4 a detailed view of the contact area between the spreading roller and the underlying contrast and/or transportation system under the second operating condition;

(6) FIG. 5 is a detailed view of the leather-detachment roller;

(7) FIG. 6 is an overall view of the output section of the machine; and

(8) FIG. 7 is an overall view of the output section of the machine wherein the rubber conveyor belt is made transparent to show a possible configuration of the leather-detachment roller.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(9) The present invention will be described hereinafter by making reference to the above-mentioned figures.

(10) In particular, FIG. 1, by way of example and according to a schematic view, shows a machine according to the present invention, at least in the parts relating to the present invention.

(11) The machine 1 illustrated in FIG. 1 is intended to the reverse leather finishing.

(12) It comprises a drawing cylinder 2 and an engraved spreading cylinder 3.

(13) Moreover, the machine 1 comprises a rubber conveyor belt 4 wound between the drawing cylinder 2acting as driving rollerand at least one idle roller 5, 8, 9. The drawing cylinder 2, in turn, comprises a rubber layer 6.

(14) The configuration of the machine is so that, in each operating configuration, a conveying surface 7 of the rubber conveyor belt 4 is tangent to the engraved spreading cylinder 3 in a point of tangency P.

(15) Advantageously, it is provided that one of the idle rollers 5, 8, 9 is a leather-detachment roller 5 and, according to the present invention, such leather-detachment roller 5 has a diameter DS comprised between 10 and 80 mm.

(16) The advantages in having a leather-detachment roller with reduced diameter DS have already been discussed previously.

(17) According to embodiments of the invention, the leather-detachment roller 5 has a diameter DS lower than 60 mm.

(18) FIG. 5 shows a detail of the leather-detachment roller 5.

(19) According to additional embodiments, the leather-detachment roller 5 can include a plurality of rollers arranged axially, with axis according to a transverse direction TR of the rubber conveyor belt 4. This possible configuration can be well seen in FIGS. 6 and 7, in particular in FIG. 7 which shows a machine according to the present invention at its output section. In particular in FIG. 7, where the rubber conveyor belt 4 is made transparent, the leather-detachment roller 5 is made visible which as a whole comprises a plurality of rollers arranged axially, with axis according to a transverse direction TR of the rubber conveyor belt 4, to cover the whole width of the rubber conveyor belt 4.

(20) According to the present invention, the drawing cylinder 2 has an overall diameter DT within the range of 200 and 250 mm, whereas the spreading cylinder has a diameter DI within the range of 140 and 190 mm.

(21) Preferably, the diameters of the two cylinders are however selected so that their ratio DT/DI is lower than 1.5. This involves a series of advantages in constructive terms.

(22) According to a preferred embodiment, its rubber layer 6 has a thickness within the range of 10 and 30 mm. Its hardness can be comprised between 15 and 35 shore.

(23) Advantageously, even the rubber conveyor belt has a hardness which can be measured in about 20-25 shore.

(24) The rubber conveyor belt 4 has a thickness ST lower than 10 mm, preferably lower than 8 mm.

(25) The reduced thickness ST of the conveyor belt, together with the reduced diameter DS of the leather-detachment roller, contributes to obtain an effective leather-detachment function, without defects.

(26) With reference to FIG. 2, this shows an enlargement of the contact area between the spreading roller and the underlying contrast and/or transportation system in a first operating condition.

(27) In such first operating condition, the arrangement of the machine is so that the point of tangency P between the spreading cylinder 3 and the conveying surface 7 of the rubber conveyor belt 4 falls exactly on the line L joining the centres of the drawing cylinder 2 and of the engraved spreading cylinder 3.

(28) In this first operating condition, then, the point of tangency P is exactly at the drawing cylinder 2, thus guaranteeing a solid and effective contrast to the pressure exerted by the spreading cylinder 3.

(29) Advantageously, the two cylinders, as in figures, can be offset with respect to a vertical line V and thus the line L joining the respective centres does not correspond exactly to the vertical V. Under vertical a line orthogonal to an ideal horizontal plane of the machine is meant.

(30) This offset, as it will be clear, facilitates the adjustment of the machine in order to bring it from an operating condition to another one.

(31) The different operating conditions, as it is evident from FIGS. 3 and 4, are defined depending upon a distance D between the driving roller 2 and the rubber conveyor belt 4, measured along the direction that joins the point of tangency and the engraved spreading cylinder 3 with the rubber conveyor belt 4 and the centre of the engraved spreading cylinder 3.

(32) The two different configurations cover a variation range of this distance D within 0 and 5 mm.

(33) With the purpose of modifying such distance D an adjustment mechanism is provided so as to allow a corresponding translation of the point of tangency P along a longitudinal direction of the rubber conveyor belt 4, according to a transport direction T.

(34) As illustrated in FIGS. 1 and 3, according to a possible embodiment, the adjustment mechanism comprises an intermediate idler roller 8, arranged between the driving roller 2 and the leather-detachment roller 5.

(35) The rotation axis of the intermediate idler roller 8 can be translated between two predefined positions along the vertical V.

(36) The translation along the vertical V of the intermediate idler roller 8 modifies the tilting of the conveyor belt 4 in the downstream tract, along the transport direction T, of the contrast area with the engraved spreading cylinder 3.

(37) The adjustment mechanism can further provide a system for translating the rotation axis of the engraved spreading cylinder 3, still along the vertical V.

(38) The translation of the rotation axis of the engraved spreading cylinder 3 along the vertical V, has the effect of increasing (or decreasing) the distance between the two cylinders 2, 3.

(39) In a particularly preferred embodiment of the invention the adjustment mechanism provides the possibility of translating at the same time, according to a vertical direction V, both the intermediate idler roller 8 and the engraved spreading cylinder 3.

(40) FIG. 4 represents a second operating condition of the machine 1, the conveyor belt 4 results to be more raised at the contact area between the cylinders and, consequently, it leaves a space D between the conveyor belt and the driving roller.

(41) A contextual translation of the rotation axis of the engraved spreading cylinder 3 along the vertical V, upwards as shown by the arrow F in FIG. 4, causes the point of tangency P to move with respect to the operating condition of FIG. 2, by translating itself along the longitudinal direction of the rubber conveyor belt 4, according to the transport direction T.

(42) In this second operating condition, the point of tangency P falls in a point wherein under the rubber conveyor belt 4 there is air (for a thickness D within the range of 0 e 5 mm). Then, evidently, in this point the spreading cylinder 3 will be subjected to a softer and more flexible contrast by the rubber conveyor belt 3 only.

(43) The use of such device involves advantages from at least two points of view: the functional one: the machine comprises the advantages of both types of roller spreading machines currently on the market (with rubber conveyor belt and with rubber roller), by allowing to widen the range of implementable articles; the management one: by using a machine which allows to synthetize two different types of machine, it allows to manage the production in a more elastic and optimized way.

(44) The present invention has been sofar described with reference to preferred embodiments thereof. It is to be meant that each one of the technical solutions implemented in the preferred embodiments, herein described by way of example, can be advantageously combined, differently with respect to what described, with the other ones, to create additional embodiments, belonging to the same inventive core and however all belonging in the protective scope of the herebelow reported claims.