SAME

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a conveyor especially suited for feeding products to kilns for baking ceramic products, such as tiles and the like.

BACKGORUND ART

In the field of manufacture of ceramic products, baking kilns of the so-called roller type are traditionally used. Such kilns comprise a tunnel support structure delimiting, between a mouth for feeding the raw ceramic products to be baked and a discharge mouth of the baked products, a channel for feeding and baking the products on a roller conveyor.

A roller conveyor of the traditional type comprises a plurality of rollers mounted transversely in the feeding and baking channel to delimit a transport plane, and arranged parallel adjacent to each other in the feeding direction A of the products in the kiln.

The rollers of the roller conveyor are driven in known manner by respective drive means arranged externally to the common feeding and baking channel of the kiln. Such drive means are designed to rotate, simultaneously and at the same speed of rotation, all the rollers of the roller conveyor, so as to allow the feeding of the products placed thereon into the feeding and baking channel at a predetermined substantially constant speed .

The feeding speed of the ceramic products within the feeding and baking channel depends on the type of product to be baked and, more particularly, on its particular ceramic composition, its thickness, etc.

At the feeding mouth of the kiln for baking ceramic materials a so-called "feeding" roller conveyor is generally provided, which conveyor is designed for feeding in the kiln the raw ceramic products from, for example, one or more production lines.

Also such a conveyor comprises a support structure on which a plurality of rollers is mounted parallel and adjacent to each other, and arranged transversely with respect to the feeding direction A of the products. The feeding conveyor includes drive means designed to simultaneously operate the rollers thereof in order to allow the feeding of the raw products arriving from one or more production lines toward the feeding mouth of the kiln.

The speed of rotation of the rollers in the feeding conveyor is substantially less than or equal to that provided, in use, for the conveyor into the feeding and baking channel of the kiln.

In kilns for baking ceramic products, the dimensions in the transverse direction of the feeding mouth are predefined and substantially corresponding to the length of the rollers of the feeding conveyor to the kiln .

The predefined transverse dimension of the feeding mouth of the kiln and the configuration of the feeding conveyor restrict the ability to fully exploit the loading possibilities of the kiln, since in traditional kilns, in a same baking cycle, only products of the same type (size and ceramic composition) can be fed, thereby leaving in some cases much unused space on the roller conveyor.

This not only limits the capacity of the kiln of ceramic products and raises the costs of production for each product but also causes an uneven baking of the ceramic products, particularly at their peripheral edges toward a portion of the roller conveyor that is unused.

It is known, in fact, that in a kiln for baking ceramic products it is crucial that the raw ceramic products are placed on the roller conveyor with the respective peripheral edges almost in contact with each other.

This serves to ensure that while baking, the hot air supplied in the kiln according to a direction incident on the plane delimited by the roller conveyor, can follow preferential paths, for example at empty spaces left between one raw product and the other, thus warming up more a product at the respective peripheral edge .

Of course, the uneven baking of the products causes the bending thereof and this results, in some cases, the resulting reject of the same.

OBJECTS OF INVENTION

The main object of the present invention therefore is to provide a conveyor suitable for feeding products into kilns for baking ceramic products, which allows increasing the production capacity of the kiln itself. Another object of the present invention is to provide a conveyor suitable for feeding products into kilns for baking ceramic products, which allows reducing the production costs of the single products.

A further object of the present invention is to provide a conveyor suitable for feeding products into kilns for baking ceramic products that can be implemented in a cost-effective manner.

Yet another object of the present invention is to provide a conveyor suitable for feeding products into kilns for baking ceramic products that allows increasing the quality of the products baked in such kilns .

According to a first aspect of the present invention, there is provided a conveyor suitable for feeding products to kilns for baking ceramic materials according to claim 1.

According to a further aspect of the present invention, there is provided a method of operation of the conveyor suitable for feeding products to kilns for baking ceramic materials according to claim 10.

Further advantageous features of the conveyor and of the respective method of operation according to the present invention are described in the dependent claims .

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects and advantages of the present invention will appear more clearly from the following detailed description of some of the currently preferred embodiments thereof, illustrated by way of non-limiting examples in the annexed drawings, wherein:

figure 1 is a top view of a roller of a conveyor suitable for feeding products to kilns for baking ceramic products according to the prior art;

figure 2 is a top view of a conveyor suitable for feeding products to kilns for baking ceramic products according to the present invention; and figure 3 is a longitudinal cross-section view, in enlarged scale, of a portion of roller of a conveyor according to the present invention.

EMBODIMENTS OF THE INVENTION.

With reference first to the accompanying figures 2 and 3, the conveyor suitable for feeding products to kilns designed for baking ceramic products according to the present invention is indicated as a whole with reference numeral 1 and includes a support structure 2, for example made by a pair of body side panels 2a and 2b, and a plurality of rollers 3 supported by the support structure 2.

The rollers of the plurality of rollers 3 are mounted transversely between body side panels 2a and 2b of the support structure 3 parallel and adjacent to each other, and delimit a transport plane T for the raw ceramic products to be fed to the kiln's mouth.

Each roller 3 advantageously includes a shaft 4 extending along a longitudinal axis X-X, which axis is orthogonal to a feeding direction A of the products on the conveyor, and supported at the ends thereof by body side panels 2a and 2b of the support structure. On shaft 4 there is rotatably mounted, for example supported by suitable bearings 5, a plurality of sleeves 6, for example a number between 6 and 8, arranged adjacent to each other, along shaft 4.

Each sleeve 6 is rotatable about shaft 4 independently of the others. The conveyor according to the present invention in fact includes drive means 7 intended for driving each sleeve 6 or groups of adjacent sleeves. In the embodiment shown in figure 3, such drive means 7 include, for example, a permanent magnet brushless motor for each sleeve 6, wherein the stator is rigidly connected, such as keyed or shrunk-on, on shaft 4 at the respective sleeve and the rotor is the sleeve itself .

According to a variant of such an embodiment, the permanent magnet brushless motor group has the stator rigidly connected, such as keyed or shrunk-on, on shaft 4, at a group of sleeves 6 adjacent to each other and the rotor is formed by the group of such adjacent sleeves .

The man skilled in the art will easily understand that, with such a configuration, in each sleeve 6 the permanent magnets of the motor group will be mounted on the surface of sleeve 6 facing towards shaft 4.

The drive means 7 can be activated, as will be better said hereafter, so that each sleeve 6 or group of sleeves in each roller of the plurality of rollers 3 can be operated and controlled in rotation independently of the others. With such a configuration, the transport plane T of the feeding conveyor according to the present invention can be divided into one or more sectors (SI and S2 in figure 2), each movable at a different speed with respect to the others. This is advantageous since it allows feeding into the kiln for ceramic materials, products with different formats and, more specifically, different sizes, thus using all the width in transverse direction of the kiln feeding mouth .

In general, the transport plane T of the feeding conveyor according to the present invention is dividable into an array consisting of as many sectors as the number of sleeves 6 or groups of adjacent sleeves present in the conveyor itself, each of them being able to rotate, suitably actuated, at a speed different from the others.

To this regard, the conveyor according to the present invention includes a program control unit 8 operationally connected to the drive means 7 for moving sleeves 6 of each roller of the plurality of rollers. More specifically, the program control unit 8 is designed, in use, to control the activation of the drive means 6 of each sleeve 7 or group of sleeves, depending on a desired rotation speed thereof.

The program control unit 8 works continuously as well as step-wise according to the operating needs of the kiln .

The conveyor according to the present invention further includes detecting means 9 operationally connected to the program control unit 8, schematically shown in figure 2.

Such detecting means 9 are provided to detect the presence or absence of ceramic products on the rollers of the plurality of rollers 3 and send a corresponding input signal to the program control unit 8.

The detecting means 9 are mounted before the feeding mouth of the kiln, for example above the transport plane T in an intermediate zone of the feeding conveyor .

The detecting means 9 can include a number of sensors capable of detecting the presence or the front edge of the ceramic products in transit, and can be for example photocells or a linear camera.

In the version of the present invention which involves a series of sensors, each sensor can be mounted at and above each sleeve 6 or a sensor may be provided at a certain number of adjacent sleeves 6, for example a sensor for two or three adjacent sleeves. It will be easily understood that other equivalent embodiments of detecting means 9 are possible, which allow detecting the presence or absence of ceramic products on the rollers of the conveyor.

Once the program control unit 8 has received in input the input signal from the detecting means 7 of each sleeve 6 or group of sleeves, is designed to determine, in a manner known to the man skilled in the art, the exact position of each ceramic product on the feeding conveyor. Based on this information, the program control unit 8 assesses whether the raw ceramic products on the conveyor are correctly arranged at the kiln loading mouth, i.e. whether each of them has the respective peripheral edges in contact with the peripheral edges of the adjacent raw products, so that the conveyor is substantially totally occupied in the transversal direction.

If this does not happen, the program control unit 8 is designed to impart to the drive means 7 of sleeves or group of sleeves a respective control signal, such as acceleration or deceleration of their rotation speed, so that, rotating at the desired rotation speed imparted by the program control unit, they arrange the raw ceramic products in input to the feeding mouth of the kiln with the respective peripheral edges in contact with those of the products adjacent to them. As will be understood, the possibility of varying the rotation speed of each sleeve 6 or group of sleeves of each roller allows effectively arranging raw ceramic products also having different formats on the conveyor without leaving empty space.

In each baking cycle, this allows loading the kiln to maximum capacity with the advantage of reducing the production costs for each product and greatly increasing the production capacity.

Also, with such a configuration of the feeding conveyor, it is possible to transport the raw ceramic products towards the kiln so that they are, at the feeding mouth of the kiln, with the respective peripheral edges in contact with each other, thereby hindering the formation of undesired preferential air flows within the feeding and baking channel of the kiln, and obtaining a homogeneous baking of the products themselves.

The conveyor according to the present invention described above may be subjected to several modifications and variations within the scope of protection of the following claims.

Thus, for example, other embodiments of the drive means 7 are possible. For example, in place of permanent magnet brushless motors, reluctance motors may be used in a known manner.

Also, the conveyor according to the present invention may be used in a similar way in output of the discharge mouth of the baked ceramic products, thus allowing the optimization of the feeding process of the baked ceramic products to the processing stations provided downstream of the baking kiln.