FR2629743A1 - Bossing method and perforating tool for the manufacture of filters made of sheet stainless steel or of plastic sheets, used for separating, by pressing, the whey from cheese curd, as well as the filter obtained by this method - Google Patents

Abstract

The method consists in passing thin sheet metal strips made of stainless steel or plastic sheets between two knurled wheels, one being grooved and the other being toothed. By pressing the rotating knurled wheels, the toothed knurled wheel drives the sheet and, in passing, forms frustoconical bosses perforated at the base and spaced apart by a series of successive intercalations of defined length, by the development of the pitch of the toothing. These perforated bosses are positioned over the surface of the filter obtained by indentations, along the two ordinates x and y. The wall of the filter is perforated along orthogonal lines.

Description

The present invention relates to the specific manufacture of tool, called a toothed wheel, the machining modes of which are characterized by the criteria set out below.

As well as the filter obtained which is used in various molds for cheese from cheese curds.

Nowadays, quantities of cheese are made by cutting the cheese curd to obtain small pieces of curd and grinding it so as to reduce it into grains, by continuous agitation in a tank.

The prepared cheese curd is racked in the molds with filters, then pressed in these molds to remove the whey and the air contained therein in order to cause the curd particles to merge together and form a block of cheese generally called "millstone".

It is used in these molds filters in silk canvas with a 2-grid grid which have the property during the molding of the block of cheese to hard form the crust of the imprints in reliefs with squares.

When unmolding the block of cheese, it turns out to be difficult to separate the canvas from the crusting, only a person skilled in the art can carry out this task.

This manufacturing process is abandoned in large and medium-sized dairy cooperative units.

Therefore, current practice is that the majority of strips of perforated stainless steel sheets or one-piece plastic mold filters are used.

Experience has shown that the perfonations of the filters should be carried out with a finish imitating the weft of the silk canvas used as a filter in the ancestral method of making cheese.

It is therefore judicious, during the separation of the cheese curd whey by pressing, to combine the criteria of adequate draining of the perfect mold release without loss of cheese and that the crusting obtained with the walls of the filter have the relief squared in the manner of this canvas formerly used.

In the use of conventional fitres, we never get the combination of the main criteria mentioned above.

The cheese wheel often presents defects, either of draining or bad mold release which depreciate this one.

A selection by quality classification is practiced on each cheese wheel.

They are referenced by categories.

Their market value is therefore different, hence the primordial importance played by the role of the filter.

By pressing the cheese curd in the molds with the filters of our invention, an adequate drainage is observed during the bonding of the curd grains. It is formed during the setting of the cheese by combination of the wall of the filters, the crusting by gridded imprints in the manner imitating the canvas, aspect sought after in the completion of the manufacture of the cheese by ripening or ripening.

It should be recognized that the manufacture of cheese is linked with the technique of manufacture of filters characterized by the perforated wall in the manner imitating the canvas.

Current perforation methods are practiced by alternating staggered holes which result directly from the ratio of the perforated surface and the remaining material, in order to balance voids and material spaces for the resistance of the material.

In patent application No. 8508290, the device is described with the so-called toothed lower wheel tool, which is initially made up of circular grooves of height h, having a face perpendicular a, a flat upper part b, a lace. oblique c and a flat lower part d.

In a second step the wheel is creased in the axial direction.

In a third step, the operation consists in removing a staggered tooth in two.

According to the present invention, it is proposed to design the toothed wheel, FIG. 1 according to the characteristics described.

First of all, the special steel wheel is machined by circular grooves having a height h of the dimension of 1.2 mm with a perpendicular face whose center distance of each groove has the dimension of 2.5 mm, a flat upper part b, of which the dimension is 0.4 mm ,. an oblique face c with a base angle of 139 20 minutes then a flat lower part d of dimension 0.8 mm
In a second step the wheel is creased in the axial direction to the gear profile fig. 2, according to module 0.5 to 20, the pitch of each division having a dimension of 3.1 mm.

After machining these successive operations, a toothed tool with a 2.5 mm circular pitch and an 3.1 mm axial pitch is obtained.

In the perforation phase of the sheet metal strip by combining the two pressure and rotating knobs. The toothing of the knurl shears the wall of the strip as a result of perforated sinking staggered by a succession of segmerts of material
Fig. 3.

the filter obtained at its perforated wall by bosses by development of vector, orthogonal lines.

A perforation by grid is obtained, characterized by the doubling of the ratio of perforations produced by a method of staggered interspersed holes.

Claims (2)

1) Toothed wheel for perfaration of characterized sheets  in that it includes circular grooves of  height h, at the side of 1.2 mm with a perpendicular face  whose center distance has, from these grooves to the coast of 2.5 mm  a flat upper part b, the coast of which is  0.4 mm, one oblique face c, the base angle of which is  139 minutes then a flat lower part d,  0.8 mm rib, axial grooves to the gear profile  (fig. 2) depending on the module 0.5 to 20, including the pitch of  each division has a dimension of 3.1 mm.  circular and axial pu of 3.1 mm.  said wheel being thus toothed in 2.5 mm steps 2) Sheet metal filter for draining, demolding,  as well as for crusting in grid reliefs characterized  in that it is obtained by perforating said sheet metal strip by means of two pressure knobs and  rotation according to claim 1.