DESCRIPTION
GRINDING MACHINE FOR TUBULAR FABRICS
BACKGROUND OF THE INVENTION
The present invention relates to a grinding machine, specifically designed for a grinding tubular fabrics.
As is known, to provide a fabric with gloss and softness properties, the fabric is subjected to a finishing process which is carried out by a grinding machine, comprising a plurality of abrasive coated cylinders, the grain size of the abrasive material depending on the result to be obtained; in such a grinding machine, the fabric is caused to pass under tension under said abrasive coated cylinders. In the case of tubular fabrics, the fabric material is flattened and, accordingly, during the grinding operation, it is not possible to properly grind the longitudinal edge portions of the fabric material . Thus, the tubular fabric piece may be affected, after a grinding process, by defects, for example a continuous line, which, while having a reduced size, constitutes anyhow a processing defect.
In prior grinding processes, using prior tubular fabric grinding apparatus, it is not possible to correct the above mentioned defect without using manual grinding operations which, however, negatively affect the end cost of the ground tubular fabric.
SUMMARY OF THE INVENTION
Accordingly, the aim of the present invention is to overcome the above mentioned
drawbacks, by providing a grinding machine, specifically designed for grinding tubular fabrics, allowing to carry out the grinding operation without causing processing defects at the fabric edge portions, and without the need of carrying out finishing grinding operations.
Within the scope of the above mentioned aim, a main object of the present invention is to provide such a tubular fabric grinding machine which is adapted to operate substantially according to the operating method of prior grinding machines, with additional advantage of providing a fully finished product.
Another object of the present invention is to provide such a tubular fabric grinding machine which, owing to its specifically designed construction, is very reliable and safe in operation.
Yet another object of the present invention is to provide such a tubular fabric grinding machine which can be easily made by starting from easily available elements and materials and which, moreover, is very competitive from a mere economic standpoint.
According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a grinding machine, specifically designed for grinding tubular fabrics, characterized in that said grinding machine comprises, on a supporting framework, a first grinding assembly, operating on a tubular fabric arranged on a first plane and a second grinding assembly, operating on said tubular fabric arranged
on a second plane angularly offset from said first plane.
BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the present invention will become more apparent hereinafter from the following detailed disclosure of a preferred, though not exclusive, embodiment of a grinding machine, specifically designed for grinding tubular fabrics, which is illustrated, by way of an indicative, but not limitative, example in the accompanying drawings, where:
Figure 1 is a perspective schematic view illustrating the grinding machine according to the invention;
Figure 2 is a further perspective view illustrating the first and second grinding assemblies included in the tubular fabric grinding machine according to the invention; Figure 3 is a side elevation view illustrating the grinding machine according to the invention;
Figure 4 is a front elevation view illustrating the grinding machine according to the invention;
Figure 5 is a top plan view illustrating the grinding assemblies included in the grinding machine according to the invention;
Figure 6 is a schematic view illustrating the arrangement of spreading disc elements inside the tubular fabric; and
Figure 7 is a cross-sectional view
illustrating, on an enlarged scale, a pair of spreading or widening disc elements .
DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the number references of the above mentioned figures, the grinding machine, specifically designed for grinding tubular fabrics, according to the present invention, which has been generally indicated by the reference number 1, comprises a supporting framework 2 , to which a tubular fabric 3 is fed from a fabric feeding station 4, of a conventional type.
The tubular fabric, in a flattened condition, is fed to a first grinding assembly, generally indicated by the reference number 10, which comprises a plurality of grinding rollers 11, operating on the tubular fabric 3 being fed.
At the outlet of the first grinding assembly, a first retractor or spreader device, generally indicated by the reference number 15, is provided, for holding the tubular fabric in a plane corresponding to that on which the grinding operation has been carried out.
The main feature of the present invention is that a second fabric retractor or spreader assembly is provided, generally indicated by the reference number 16, which is construction-wise like to the assembly 15 and operates to spread the fabric on a second plane, likewise offset from the first plane on which the tubular fabric at the first spreader assemblies lays.
Downstream of the second spreader assembly,
a second grinding assembly, generally indicated by the reference number 20 is arranged; said second grinding assembly performs a further grinding operation on the fabric and, most importantly, it performs the grinding operation on the lines, indicated by 30, which are formed at the tubular fabric 3 edge portion during the first grinding operation.
As clearly shown in figures 6 and 7, the spreader assemblies 15 and 16 comprise spreading disc elements 21 and 22 which are opposite to one another and are rotatably supported by respective supporting pin elements 23 and 24.
Said pin elements engage on the outside of the fabric 3, at the edge portions thereof.
In order to hold the fabric in a spread apart position, a toroidal ring element 25 is arranged inside said tubular fabric 3, said ring element engaging between the rollers thereby preventing the tubular fabric from disengaging from the disc element.
Said ring element 25 has a cross-section larger than the spacing of the spreader discs 21 and 22. Thus, it is possible to "open" the fabric along a plane which is different from, and in particular perpendicular to, the plane on which the fabric is arranged during the passage thereof through the first grinding assembly. Such an arrangement allows, in a single operating passage, to perform a full operating process on the overall extension of the fabric and,
in particular, it allows to carry out the grinding process also at the edge portions of the fabric, thereby preventing any further grinding operations from being successively performed. From the above disclosure it should be apparent that the invention fully achieves the intended aim and objects.
In particular, the fact is to be pointed out that the grinding machine according to the present invention allows to perform, by very simple operating means, an optimum finishing continuous process through the overall extension of the tubular fabric.
The invention, as disclosed, is susceptible to several modifications and variations, all of which will come within the scope of the invention.
Moreover, all the constructional details can be replaced by other technically equivalent elements . In practicing the invention, the used materials, as well as the contingent size and shapes can be any, according to requirements.