Technical Field

The present invention relates to a pressing wheel.

Background Art

With particular but not exclusive reference to the sector of ceramic industry for the manufacture of products such as tiles, slabs or bricks, it is known to move the artifacts by means of appropriate movement lines inside the plants and/or when crossing machinery intended for the processing of products.

In some circumstances, such as e.g. in the passage through squaring machines, it is necessary that the products remain stably on the movement line while their lateral edges are processed by means of grinding and beveling wheels.

It is easy to understand how in these cases the centering of the product with respect to the squaring machine, or in general with respect to another type of machine, is very important to avoid manufacturing defects on the product.

In this regard, the use is known of pressing wheels which, by pressing the products downwards, keep them in position during their movement along the transport lines.

The wheels of known type have a metal bush support element, supporting an outer rolling body made of polymeric material of the type of hard rubber or the like and glued to the outer surface of the bush support element.

The bush support element in turn is mounted around a rotational ball bearing and carries, on the opposite sides of the bearing, lateral protection elements substantially partition-like, designed to prevent the entry of dust into the rotational bearing.

The central part of the rotational bearing is associated with a bracket that allows the arrangement thereof in series along the transport lines and the free rotation of the outer rolling body around the axis of rotation of the bearing by simple sliding contact with the products passing on the transport lines.

In particular, the brackets are mounted above the transport lines so that the wheels push downwards the artifacts moving forward, and keep them pressed on the transport lines.

The wheels of known type do however have some drawbacks among which the fact must be considered that they have high manufacturing costs due to the need to provide a bush support element on which the outer body must be glued and, also, due to the presence of the lateral protection elements.

Another drawback is represented by the fact that the weight of the outer rolling body, during rotation, is discharged entirely on the bush support element and consequently on the rotational bearing, thus causing the balls of the rotational bearing to wear quickly.

In this regard it is underlined that, as it is easy to understand, any maintenance and replacement jobs on the wheels, due to their quick wear, involve not negligible additional costs.

Description of the Invention

The main aim of the present invention is to provide a pressing wheel that has low manufacturing costs, leading to a total decrease in the cost of approx. 25%. Another object of the present invention is to provide a pressing wheel which offers considerable resistance to wear, and consequently makes it possible to reduce maintenance and replacement costs.

Another object of the present invention is to provide a pressing wheel which allows to overcome the mentioned drawbacks of the prior art within the ambit of a simple, rational, easy and effective to use as well as affordable solution. The above mentioned objects are achieved by the present pressing wheel having the characteristics of claim 1.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become better evident from the description of a preferred, but not exclusive, embodiment of a pressing wheel, illustrated by way of an indicative, but non-limiting example in the accompanying drawings, wherein:

Figure 1 is an exploded view of a wheel according to the invention in a first embodiment;

Figure 2 is a sectional view of the wheel of Figure 1 ;

Figure 3 is an exploded view of a wheel according to the invention in a second embodiment;

Figure 4 is a sectional view of the wheel of Figure 3. Embodiments of the Invention

With particular reference to such figures, reference number 1 globally indicates a pressing wheel.

The wheel 1 comprises a rotational bearing 2, 3, 4.

The rotational bearing 2, 3, 4 comprises an inner annular element 2, associable with a support 20, 21, 22 and an outer annular element 3 arranged around the inner annular element 2 to define a first space 5.

The outer annular element 3 and the inner annular element 2 have a substantially circular shape.

Furthermore, the rotational bearing 2, 3, 4 comprises a plurality of rolling elements 4 positioned between the inner annular element 2 and the outer annular element 3 and housed in the first space 5.

The outer annular element 3 and the inner annular element 2 comprise inside them a sliding seat of the rolling elements 4.

The sliding seats have a substantially annular shape and have an angular extension substantially equal to 360°; this means that they entirely surround the annular elements 2, 3.

Furthermore, the wheel 1 comprises an outer rolling body 6 made of a polymeric material and supported by the outer annular element 3.

Advantageously, the outer rolling body 6 is made of polyurethane.

Conveniently, the outer rolling body 6 is co-molded on the outer annular element 3.

It is useful to point out that by the term "co-molded" is meant a high-pressure casting and/or injection industrial process, through which the polymeric material is melted and introduced inside a closed mold in which the outer annular element 3 was previously housed.

The solidification of the polymer material takes place, therefore, when it is already in contact with the outer annular element 3, which determines their mutual adhesion.

By means of co-molding, the outer rolling body 6 is shaped to define two lateral annular flanges 7 adapted to cover at least part of the first space 5.

It is useful to point out that in the present discussion the term "lateral" is meant as referred to an operating configuration in which the rotational bearing 2, 3, 4 can be operated in rotation around a central axis 8 by sliding contact of the outer rolling body 6 with a work surface (in this case a tile) substantially parallel to the central axis 8.

Advantageously, the central axis 8 is horizontal and the work surface is movable with respect to the wheel 1 along an advancement direction substantially perpendicular to the central axis 8.

Usefully, the lateral annular flanges 7 have a substantially circular central opening 9.

By reference to the figures, the wheel 1 also comprises two lateral closing elements 10, 11 insertable from opposite sides into a second space 12 defined inside the inner annular element 2.

In the present case, each lateral closing element 10, 11 is inserted laterally in a specular manner with respect to the other lateral closing element 10, 11; this means that the two lateral closing elements 10, 11 have a similar front position and are arranged one on each side of the wheel 1.

The lateral closing elements 10, 11 have a first portion 10, insertable inside the second space 12, and a second portion 11, which remains outside the second space 12.

Advantageously, the first portion 10 and second portion 11 of each lateral closing element 10, 11 are made in the form of a single monolithic body.

The first portion 10 has the shape of a straight cylinder with a diameter substantially mating with the inner diameter of the inner annular element 2. In particular, the first portion 10 is shaped so as to fit substantially snugly or with a slight interference inside the second space 12, adhering to a lateral side 13 of the inner annular element 2.

Advantageously, the second portion 11 has the shape of a straight cylinder coaxial to the first portion 10.

Usefully, the second portion 11 has a diameter substantially larger than the diameter of the first portion 10, this way the portions 11 comprise a lateral supporting surface 14 adapted to come in contact with the lateral sides 13 opposite the inner annular element 2. The diameter of the second portion 11, furthermore, is substantially mating with the diameter of the central openings 9. In this case, the fact that the second portion 11 has a diameter substantially mating with that of the central openings 9 means that the diameter of the second portion 11 is slightly less than the diameter of the central openings 9.

In other words, the second portion 11 is insertable with play in the central openings 9 and, in the assembly configuration, between the second portion 11 and the inner walls 16 of the central openings 9 is defined a non-contact empty space 15 between the second portion 11 and the outer rolling body 6.

In practice, in the operating configuration, but in the absence of contact between the outer rolling body 6 and the work surface, the empty space 15 allows the perfect rolling of the rotational bearing 2, 3, 4, which takes place by means of the rotation of the rolling elements 4.

On the contrary, in the presence of contact between the outer rolling body 6 and the work surface, the pressing force applied by the outer rolling body itself on the rotational bearing 2, 3, 4 may deform the lateral annular flanges 7, bringing them in contact with the second portions 11; this leads to a local friction between the inner walls 16 and the second portions 11 which allows to unload the weight of the outer rolling body 6 (meant as pressing force) also on the closing elements 10, 11 and not entirely on the rolling elements 4.

It is underlined that the play, i.e. the empty space 15, is such as to prevent the entry of dust in the first space 5, thus guaranteeing the maintenance of optimum conditions of cleanliness of the rolling elements 4.

In addition, the dust-proof seal offered by the empty space 15 can also be made hermetic. In a second embodiment shown in Figures 3 and 4, in fact, the lateral closing elements 10, 11 comprise a housing seat 17 of a sealing element 18.

In particular, the housing seat 17 has a substantially annular shape and is formed on the second portion 11.

Similarly, the sealing element 18 also has a substantially annular shape and is adapted to seal the first space 5 hermetically.

Usefully, the sealing element 18 is a rotary shaft sealing ring (oil seal).

The lateral closing elements 10, 11 comprise at least a through hole 19 that crosses them from side to side and allows the assembly of the wheel 1 on the support 20, 21, 22.

As in fact visible in Figures 2 and 4, the wheel 1 is associated with a bracket comprising two holding bars 22 having an opening for the passage of a pin element 20, of the type of a screw or the like.

The pin element 20 is insertable in the through holes 19 of the lateral closing elements 10, 11 and has at least one tightening element 21, of the type of a nut or the like, associated with the pin element 20 for locking in a sandwich-like fashion the lateral closing elements 10, 11 and, also, the tightening of the lateral supporting surfaces 14 against the lateral sides 13.

This way, the inner annular element 2 is blocked through the fixing of the bracket to the holding bars 22.

In other words, the inner annular element 2 is immobilized in an integral manner to the support 20, 21, 22 by means of the tightening element 21.

It has been found in practice how the described invention achieves the intended objects.

In particular it is underlined that the particular device to have an outer rolling body co-molded on the outer annular element of the rotational bearing, allows to greatly simplify the manufacturing process and to decrease the manufacturing costs of approx. 25%.

To this one should add that the presence of the lateral closing elements allows a better distribution of the weight of the outer rolling body and further protects the rotational bearing from external agents during the processing phase, thus lengthening the times of use of the wheel and leading to a reduction in the maintenance and replacement costs.