WO2012052960A1

WO2012052960A1 - Walking-beam conveyor and a furnace, in particular for the thermal treatment of metallurgical products, comprising such a conveyor

Info

Publication number: WO2012052960A1
Application number: PCT/IB2011/054697
Authority: WO
Inventors: Bruno Gaggero; Marcello Tomolillo
Original assignee: Tenova S.P.A.
Priority date: 2010-10-22
Filing date: 2011-10-20
Publication date: 2012-04-26
Also published as: IT1402528B1; ITMI20101955A1

Abstract

The present invention refers to a walking-beam conveyor (1), comprising at least one fixed beam (2) extending in a direction parallel to the conveying direction (D) and at least one walking beam (5) extending on the side of and parallel to the fixed beam (2), wherein the walking beam (5) is mobile with respect to the fixed beam (2) with an alternate motion component in an orthogonal direction with respect to the plane parallel to that defined by the beams between a lowered position and a raised position with respect to the fixed beam (2) and with an alternate rectilinear motion component in a direction parallel to the conveying direction (D) between a first position and a second position, advanced with respect to the first one, the conveyor (1) further comprising a mobile frame (6) supporting the at least one walking beam (5), rolling organs (7) associated with the frame (6) for supporting the same on the ground (S), said rolling organs being rotatable around an axis parallel to said plane and orthogonal to said conveying direction (D), a leverage (10) articulated to the frame (6) for raising and lowering the same with respect to the ground (S) and thus the at least one walking beam (5) with respect to the fixed one (2), first actuating means (11) of the leverage (10) for the alternate displacement of the frame (6) between a raised position and a lowered position with respect to the ground (S) and therefore for the alternate displacement of the at least one walking beam (5) between the raised position and the lowered position and second actuating means (12) of the frame (6) in alternate rectilinear motion in a direction parallel to the conveying direction (D) for the alternate displacement of the same and, therefore, of the at least one walking beam (5) between the first and the second position.

Description

WALKING-BEAM CONVEYOR AND A FURNACE, IN PARTICULAR FOR THE THERMAL TREATMENT OF METALLURGICAL PRODUCTS, COMPRISING SUCH A CONVEYOR The present invention refers to a walking-beam conveyor and a furnace, in particular a furnace for the thermal treatment of metallurgical products, of the rough-shaped, billet and similar types, comprising such a conveyor .

With particular reference to the metallurgical field, tunnel furnaces for the thermal treatment of products, such as, for example, rough-shaped, billets and the like have been known for a long time, inside which the products, supplied in inlet by proper means, are conveyed towards the outlet, where they are taken by corresponding proper means, by a continuous conveyor of the walking-beam type. The use of a walking-beam conveyor, indeed, limits the contact time between the treated products and the support elements (beams) of the conveyor itself.

Typically, a walking-beam conveyor comprises a plurality of fixed beams, which extend, separated one from the other, parallel to the conveying direction, alternated with a plurality of walking beams, which extend between the fixed beams in a direction parallel to the conveying direction. The walking beams are cyclically moved between:

- a position lowered and aligned with the fixed beams, wherein the products rest on the latter,

- a position raised and aligned with the fixed beams, wherein the products are raised by the fixed beams and rest on the walking beams; - a position raised and advanced with respect to the fixed beams, wherein the products, still resting on the walking beams, are made to advance by one step along the conveying direction, and

- a position lowered and advanced with respect to the fixed beams, wherein the products, advanced by one step, are released resting on the fixed beams.

The walking beams, therefore, are equipped with an alternate motion both with a component orthogonal to the plane defined by the fixed beams to move between a lowered position and a raised position with respect to the fixed beams, and with a component parallel to the conveying direction between a first position, wherein they are aligned to the fixed beams, and a second position, wherein they are advanced with respect to the fixed beams.

The two motion components are given to the walking beams by respective movement systems which act upon the carriages, leverages or the like.

In known movement systems, be they of the mechanical, electro-mechanical or hydraulic/oil hydraulic type, both the power generators (motors, pumps, compressors) , and the actuators that transform and transmit the generated power to the walking beams in order to actuate a movement thereof according to one of the two motion components (horizontal translation and raising and lowering movements) , such as, for example, rod-crank, eccentric and rod mechanisms or cylinder-piston linear actuators, are supported at the ground and are connected to carriages or other systems that support the beams in a movable manner.

Such movement systems of the known type discharge to the ground the reaction loads and, in particular the reaction loads for the raising and the lowering of the walking beams, which, as it can be easily understood by a man skilled in the art, are greater than those deriving from the sole horizontal translation of the walking beams, being proportional to the weight.

In particular, the movement systems of the known type discharge to the ground all the reaction loads, be they of the compression or of the shearing type, at the anchor points of the motors and of the actuators, where, therefore, the tensions concentrate.

This requires reinforcement and structural armour work of the ground and, in the case of furnaces, of the basements of the furnaces themselves, which are substantial, complex and onerous even from an economic point of view. This work is made particularly substantial and burdensome also by the weight of known movement systems.

Moreover, known movement systems are particularly bulky in height. For this reason it is necessary to build them into deep containment pits obtained below the transport plane defined by the beams themselves. This, obviously, requires availability of space and the execution of particularly complex and costly excavation and strengthening works.

The purpose of the present invention is that of avoiding the aforementioned drawbacks of the prior art.

In the field of such a general purpose, one particular purpose of the present invention consists in providing a walking-beam conveyor which permits to reduce the entity of the reaction loads transmitted to the ground and to transmit them to the ground in a distributed manner.

Another purpose of the present invention is that of providing a walking-beam conveyor having weight and bulk less than the walking-beam conveyors of the known type .

A further purpose of the present invention is that of providing a walking-beam conveyor which permits to limit the reinforcement and structural armour work of the relative support basement and to limit the dimensions, in particular the depth, of the relative containment pit, reducing the excavation work necessary to realize it.

Another purpose of the present invention is that of realizing a walking-beam conveyor that is particularly simple and functional, with low costs and that can be easily installed even in already existing furnaces.

These and other purposes are achieved through a walking-beam conveyor as outlined in claim 1.

Further characteristics are outlined in the dependent claims 2-18.

These purposes are moreover achieved through a furnace, particularly for the thermal treatment of metallurgical products, as outlined in claim 19.

The characteristics and the advantages of a walking-beam conveyor and of a furnace, particularly for the thermal treatment of metallurgical products, comprising such a conveyor, according to the present invention will become clearer from the following description, exemplifying and not limiting, referring to the attached schematic drawings wherein:

figure 1 is a schematic and partially sectioned view of a first embodiment of the conveyor according to the present invention applied to a furnace for the thermal treatment of metallurgical products with the walking beams in the raised and advanced position with respect to the fixed beams;

figure 2 is an analogous view to that of figure 1 with the walking beams in the lowered and advanced position with respect to the fixed beams;

figure 3 is a section view according to the plane A-A of figure 1 showing the frame of the conveyor according to the present invention and the first and second actuating means;

figures 4 and 5 are schematic and partially sectioned views according to the plane B-B of figure 3 of the first embodiment of the conveyor according to the present invention in a position corresponding to that of figure 1 and of figure 2, respectively;

figure 6 shows an enlarged detail of figure 3;

figures from 7 to 12 are views like those of figures 1 to 6 of a second embodiment of the conveyor according to the present invention.

With particular reference to the attached figures a walking-beam conveyor is wholly indicated with 1.

The conveyor 1 can be applied to a furnace 100, in particular a furnace for the thermal treatment of metallurgical products P, of the billet, rough- shaped and similar types.

The furnace 100 comprises a thermal treatment chamber 101 equipped, at the opposite ends, with an inlet 102 and an outlet 103 for the products P, which are supplied at the inlet 102 and removed from the outlet 103 by respective means which are not shown, being of the known type. In the embodiment shown, the inlet 102 and the outlet 103 are arranged at the side of the furnace 100, this does not exclude them from being provided in line with the conveying direction of the products P inside the furnace itself.

The conveyor 1 extends between the inlet 102 and the outlet 103 to transport the products P from one to the other along the conveying direction D.

The conveyor 1 comprises one or more fixed beams 2 which extend parallel to the conveying direction D.

The fixed beams 2 are supported by uprights 3 anchored to a frame 4 which is built into the basement 104 of the furnace 100 and that is anchored to the ground S defined by the basement 104 itself.

The uprights 3 pass through openings 105 formed in the floor slab 106 which delimits the chamber 101 with respect to the basement 104.

The fixed beams 2 are alternated with one or more walking beams 5 which extend parallel to the conveying direction D and which are typically mobile both with an alternate motion component in an orthogonal direction with respect to the plane defined by the fixed beams 2 between a lowered position and a raised position with respect to the fixed beams 2, and with an alternate, rectilinear motion component in a direction parallel to the conveying direction D between a first and a second position advanced with respect to the first. In the attached figures the two motion components of the walking beams 5 are schematised with the double arrows F and G.

The upper surface of both the fixed beams 2, and the walking beams 5 is groove-shaped, for example, for supporting the products P. According to a peculiar characteristic of the present invention, the walking beams 5 are supported by a frame 6 that is mobile with motion having components F and G.

Rolling organs are associated with the frame 6, by means of which the frame 6 rests on the ground S of the basement 104 with the possibility of sliding horizontally along the conveying direction D. The rolling organs are made up of, for example, wheels 7, rollers or the like, which are rotatable around an axis defined by a pin 8 parallel to the plane of the beams and orthogonal to the conveying direction D.

The wheels 7, in particular, rest on plates 9 fixed to the ground S .

The frame 6, moreover, is articulated to a leverage

10 for raising and lowering the frame 6 itself with respect to the ground S and, therefore, the walking beams 5 integral to it with respect to the fixed beams 2.

First actuating means 11 of the leverage 10 are also provided for the alternate displacement of the frame 6 between a raised position and a lowered position, respectively corresponding to the raised and lowered positions of the walking beams 5 with respect to the fixed beams 2 (component of motion F) and second actuating means 12 of the frame 6 in an alternate rectilinear motion parallel to the conveying direction D between a first and a second position advanced with respect to the first, respectively corresponding to the first and second position of the walking beams 5 with respect to the fixed beams 2 (component of motion G) .

According to one peculiar characteristic of the present invention, at least one of the first actuating means 11 and the second actuating means 12 are supported by the frame 6 with which, therefore, they move as a unit. In particular, the first actuating means 11 are supported by the frame 6 and are operatively associated with the leverage 10 so as to permit the horizontal sliding of the frame 6 along the conveying direction D actuated by the second actuating means 12. The second actuating means 12 are in turn supported by the frame 6 and are operatively associated with the ground S or with a fixed wall so as to leave free the rising and lowering displacement of the frame 6 with respect to the ground S .

It is specified, moreover, that in the present description by "first actuating means" and "second actuating means" it is meant to indicate means of the mechanical, oil -hydraulic, hydraulic or electric type, for transforming and transmitting power generated by corresponding means (motors, pumps, compressors) - not necessarily supported by the frame 6 itself - to the frame 6 itself, so as to actuate the movement according to the two aforementioned components F and G.

More in detail, the leverage 10 comprises at least one pair of levers 13 substantially L-shaped which, near the angle of connection between the two arms of the L, are hinged to the frame 6 in a rotary way around an articulation axis defined by a pin 14 parallel to the plane of the beams and orthogonal to the conveying direction D. The two arms of the L form with each other an angle that is greater than or equal to 90° and the levers are arranged mutually parallel.

Each lever 13 has the upper end articulated with at least one transmission rod 15 in a rotary way around a respective articulation axis defined by a pin 16 parallel to the pin 14.

Finally, at least one respective wheel 7 is associated with the lower end of each lever 13, by means of the respective pin 8. The wheels 7, or analogous rolling organs, therefore, are indirectly associated with the frame 6 by means of the levers 13.

Each pair of levers 13, the transmission rod 15, the frame 6 and the respective articulation pins 14 and 16 define an articulated quadrilateral, wherein the transmission rod 15 moves with a component parallel to the conveying direction D.

In a preferred embodiment, a plurality of levers 13 is provided, distributed and mutually spaced along the extension of the frame 6 parallel to the conveying direction D and the transmission rod 15 comprises a train of rods 17 articulated two-by-two by a respective link-rod 18 to which the upper end of a respective lever 13 is articulated. The articulation pins of the rods 17 to the link-rods 18 are indicated with 19.

In the embodiment represented in the attached figures, the frame 6 comprises a plurality of beams 20 which extend parallel to the conveying direction D and between which cross beams 21 extend.

The cross beams 21 support the uprights 22 to which the walking beams 5 are fixed. In such a case as well, the uprights 22 pass through the openings 105' defined passing in the floor slab 106.

Each outer beam 20 is associated with a corresponding leverage 10 as described above and with corresponding first actuating means 11, coordinated with each other in a synchronised manner.

As already mentioned, according to a peculiar characteristic of the present invention, the first actuating means 11 of the leverage 10, leverage which, as shall become clearer in the following of the description, gives the frame 6 an alternate displacement in a direction orthogonal to the ground S (component F) , or rather to the plane defined by the fixed beams, are supported by the frame 6 with which they move as a unit.

In particular, the first actuating means 11 act upon the transmission rod 15 actuating it in motion with a component parallel to the conveying direction D. Such a motion of the transmission rod 15 generates the rotation of the levers 13 around their fulcrum defined by the pin 14 of articulation to the frame 6. The corresponding rotation of the lower arms of the levers 13, which rest on the ground S by means of the wheels 7, raises or lowers the entire frame 6 and, therefore, the walking beams 5 carried by it.

It is specified that during such a motion of the frame 6 (component F) , the second actuating means 12 are inactive (not operative), i.e. the displacement of the frame 6 along the conveying direction D (component G) is inhibited.

The second actuating means 12, on the other hand, give the frame 6 a displacement in a direction parallel to the conveying direction D (component G) . Such a displacement of the frame 6 occurs thanks to the rolling motion of the wheels 7 on the ground S.

According to one peculiar characteristic of the present invention, the second actuating means 12 as well can be supported by the frame 6; in any case, however, they will act between the frame 6 and a fixed element, be it made up of the ground S or of a wall of the basement 104.

Analogously to the above, when the frame 6 actuated in a sliding motion along a direction parallel to the conveying direction D (component G) by the second actuating means 12, the first actuating means 11 are inactive (not operative) ; the raising and lowering motion of the frame 6 with respect to the ground S (component F) is, that is to say, inhibited.

Figures 1-6 and 7-12 show two different embodiments of the conveyor 1 which differ from one another only in the way the respective first and second actuating means 11 and 12 are realized.

With particular reference to figures 1-6, the first actuating means 11 comprise at least one first linear actuator 23 which has the opposite ends respectively hinged to the transmission rod 15 and to the frame 6 in a rotary way around a respective hinging axis 24 and 25 parallel to the plane defined by the beams and orthogonal to the conveying direction D.

In particular, the first linear actuator 23 is made up of a fluid medium cylinder-piston unit; however, alternative embodiments of the first linear actuator 23 which, for example, could be of the electric type, should not be excluded.

In figure 2, the first linear actuator 23 is in its extended configuration with the frame 6 in the lowered position.

When the first linear actuator 23 passes from the extended configuration to the retracted configuration (figure 1) , the levers 13 rotate in an anti-clockwise direction raising the frame 6 with respect to the ground S and, therefore, the walking beams 5, fixedly attached to it, with respect to the fixed beams 2, the displacement of the frame 6, in direction parallel to the conveying direction D being prevented by the second actuating means 12 that are kept inactive.

Vice versa, when the first linear actuator 23 passes from the retracted configuration to the extended one, keeping the second actuating means 12 inactive, the levers 13 rotate in the clockwise direction lowering the frame 6 with respect to the ground S and, thus, the walking beams 5, fixedly attached to it, with respect to the fixed beams 2.

It is noted that the first linear actuator 23 for actuating the leverage 10 is supported by the frame 6, which in turn rests on the ground by means of the sole wheels 7. In such a way, on the ground S only compression stresses orthogonal to it act, whereas the remaining forces generated by the raising or lowering movement of the frame 6 discharge onto the frame 6 itself .

Of course, each leverage 10 associated with a respective beam 20 is actuated by one or more corresponding first linear actuators 23. The various first linear actuators 23 are coordinated one with the other in a synchronised manner.

Again with reference to figures 1-6, the second actuating means 12 are also made up of at least one corresponding second linear actuator 26 which has the opposite ends associated respectively with the frame 6 and with the ground S or with a fixed wall of the basement 104.

In the embodiment shown, the second linear actuator 26 has the opposite ends respectively hinged to the frame 6 and to a base 27 anchored to the ground S around respective pins 28 and 29 parallel to the plane defined by the beams and orthogonal to the conveying direction D.

However, alternative embodiments are not excluded, wherein, for example, also the second linear actuator 26 is supported by the frame 6 and is articulated to the ground S or to a fixed wall of the basement 104 through a rod.

Even in such a case, moreover, the second linear actuator 26 is made up' of a fluid medium cylinder- piston; however, alternative embodiments of the second linear actuator 26 are not excluded, which, for example, could be of the electrical type.

In both figures 4 and 5, the second linear actuator 26 is in its extended configuration; when the second linear actuator 26 passes from the extended configuration to the retracted one, keeping the first actuating means 11 inactive, the frame 6, thanks to the rolling support on the ground S, slides parallel to the conveying direction D moving back with respect to the position shown in the aforementioned figures 4 and 5.

It is noted that the second linear actuator 26 gives the frame 6 an action of thrust or of traction parallel to the conveying direction D actuating the sliding, by rolling of the wheels 7 on the ground S, forwards and backwards (component G) . The stresses which in such a case discharge on the ground S or on the fixed wall of the basement 104 are of an entity at least one order of magnitude smaller with respect to those due to the raising and the lowering of the frame 6, being proportional to the mass, but not to the weight .

If then the second linear actuator 26 is articulated to a fixed wall of the basement 104 and not to the ground S, the stresses which discharge onto it are substantially orthogonal to it.

The first linear actuator 23 and the second linear actuator 26, finally, are in communication with a hydraulic/oil hydraulic circuit, not represented since a man skilled in the art could easily make it.

In the second embodiment represented in figures 7- 12, the first actuating means 11 comprise first mechanical means for transforming and transmitting the rotary motion of a first shaft 30, actuated in rotation by motor means 31, into alternate rectilinear motion of the transmission rod 15.

In greater detail, the motor means 31, made up for example of an electric gearmotor 32, are anchored to the ground S .

The first shaft 30 is supported by the frame 6 in a rotary way around an axis parallel to the plane defined by the fixed beams and orthogonal to the conveying direction D.

A transmission shaft 33 transmits the rotary motion from the motor means 31 to the first shaft 30; the opposite ends of the transmission shaft 33 are respectively associated with the drive shaft and with the first shaft 30 by means of articulated joints 34 suitable for permitting the displacement of the frame 6 and, therefore of the first shaft 30 fixedly attached to it, along both the motion components F and G.

Figure 9 represents two positions of the transmission shaft 33.

On the first shaft 30 a first disc 35, rotating as a unit with it, is mounted in an eccentric manner.

The first disc 35 is housed in a rotary way in a first collar 36 which is defined at the end (foot) of a rod 37, the opposite end of which is articulated to the transmission rod 15.

The rotation of the first disc 35, therefore, translates into an alternate motion of the rod 37, or rather of the head of the rod 37, and, therefore, of the transmission rod 15, with a component parallel to the conveying direction D.

In figures 7 and 8, the first disc 35 is represented in the two extreme configurations of top and bottom dead centre of the rod 37.

With particular reference to the embodiment represented in figure 9, wherein two outer beams 20 are present each equipped with a respective leverage 10 and with corresponding first actuating means 11, it is noted that the latter take motion from common motor means 31 by means of a respective transmission shaft 33.

Even in such a case, only compression stresses orthogonal to it act on the ground S, whereas the remaining forces generated by the raising or lowering motion of the frame 6 discharge onto the frame 6 itself .

Again with reference to figures 7-12, the second actuating means 12 comprise second mechanical means for transforming and transmitting the rotary motion of a second shaft 38 into alternate rectilinear motion of the frame 6.

In greater detail, the second shaft 38 is supported in a rotary way to the ground S around an axis parallel to the plane of the beams and orthogonal to the conveying direction D. In particular, the opposite ends of the second shaft 38 are supported by a corresponding support 39 constrained to the ground S.

The second shaft 38 is actuated in a rotary way by respective motor means 40, of the type, for example, of an electric gearmotor 41, by means of a corresponding transmission shaft 42.

On the second shaft 38 a second disc 43, which rotates as a unit with it, is mounted in an eccentric manner.

The second disc 43 is housed in a rotary way in a second collar 44 which is in turn mounted on a slide 45 in a rigid manner.

On the frame 6 a guide body 46 is rigidly fixed, in which the slide 45 is slidably supported so that one can slide with respect to the other in a direction orthogonal to the plane defined by the beams, or rather in a direction orthogonal to the ground S.

It is noted that in such a case the opposite ends of the transmission shaft 42 are rigidly coupled to the drive shaft of the motor means 40 and to the second shaft 38, the drive shaft, the transmission shaft 42 and the second shaft 38 being coaxial one with the other. In such a case, indeed, any translation displacement of the second shaft 38 and, consequently, of the second disc 43 fixedly attached to it, at least along the component G, must be prevented. As it can be easily understood by a man skilled in the art, the rotation of the second disc 43, being the guide body 46 capable of sliding, by means of the slide 45, with respect to it in a direction orthogonal with respect to the ground S, gives the guide body 46, and, therefore, the frame 6 rigidly connected to it, an action parallel to the conveying direction D for the sliding of the frame 6 parallel to such a direction.

Even in such a case, with reference to figure 9, with the two outer beams 20, respective second actuating means 12 are associated, which receive the motion from common motor means 40 through a respective transmission shaft 42.

With reference to figures 1-12, finally, guiding means 50 for the frame 6 are present.

As already indicated, when the first and the second actuation means 11 and 12 are alternatively and selectively active, the first actuating means 11 give the frame 6, through the leverage 10, an alternate motion in a direction orthogonal with respect to the ground S, the second actuating means 12 being inactive, preventing, in such a way, the translation of the frame 6 parallel to the conveying direction D. The second actuating means 12, on the other hand, give the frame 6, sliding on the ground S by means of wheels 7, an alternated sliding motion parallel to the conveying direction D, the first actuating means 11 being inactive, preventing, in such a manner, any movement of the frame 6 in a direction orthogonal with respect to the ground S itself.

As it can be easily understood by a man skilled in the art, the walking beams 5 are thus cyclically mobile between :

- a position wherein they are lowered with respect to the fixed beams 2, or rather wherein the resting surface of the walking beams 5 is at a lower height with respect to the ground S than the height at which the resting surface of the fixed beams 2, is located and aligned with them; in such a position the products P rest on the fixed beams 2 ;

- a position wherein they are raised with respect to the fixed beams 2, or better wherein the resting surface of the walking beams 5 is at a greater height with respect to the ground S than the height at which the resting surface of the fixed beams 2 is located, and aligned with them; in such a position the products P are raised by the fixed beams 2 and rest on the walking beams 5 ;

- a position wherein they are raised with respect to the fixed beams 2 and advanced with respect to them along the conveying direction D; in such a position the products P, resting on the walking beams 5, advance by one step along the conveying direction D (figures 1 and 7) ; and

- a position wherein they are lowered with respect to the fixed beams 2 and advanced with respect to them along the conveying direction; in such a position the products P are released resting on the fixed beams 2 in an advanced position by one step with respect to the starting position (figures 2 and 8) .

It has practically been proved that the conveyor according to the present invention permits to limit the seriousness of the reaction loads, in particular those deriving from the raising and the lowering of the walking beams, transmitted to the ground and, therefore, permits to limit the reinforcement and structural strengthening work of the ground itself.

Indeed, in the conveyor according to the present invention, the walking beams are supported by a mobile frame that rests on the ground only by means of rolling organs (wheels) which only transmit compression loads to the ground itself.

Moreover, according to the present invention, the support frame of the walking beams is made alternatively mobile along a direction orthogonal to the ground itself - for raising and lowering the walking beams - by means of a leverage actuated by first actuating means supported by the frame itself and not, on the other hand, from the ground, like in known type systems.

This permits to further limit the reaction loads, in particular the shearing loads, transmitted to the ground.

The rolling organs (wheels) , moreover, are hinged to the same raising/lowering leverage of the frame, so that the raising and lowering loads of the frame are transmitted to the ground only as compression loads.

By increasing the number of levers and, therefore, of rolling organs for supporting on the ground, a greater distribution and reduction of the entity of the single reaction loads is achieved.

The reaction loads due to the horizontal sliding of the frame, on the other hand, are transmitted by the second actuating means to the ground or to a wall, the entity of such loads is, however, lower than that of the reaction loads of raising/lowering the frame itself, therefore the reinforcement and structural armour work are limited in such an area.

The conveyor according to the present invention, moreover, has a smaller bulk with respect to known conveyors, in particular in height, which permits to reduce the depth of the pit or of the containment basement and, therefore, to limit the relative excavation work.

The conveyor according to the present invention can undergo numerous modifications and variants, all covered by the invention; moreover all details can be replaced by technically equivalent elements. In practice, the materials used, as well as the dimensions, can be any according to the technical requirements .

Alternative embodiments of the first and second actuating means are not excluded, which, for example, could be of the pinion and rack type . The embodiment of the first and second actuating means, indeed, is not binding or limiting, notwithstanding that the peculiar characteristic of the present invention is that of having made the beams mobile and fixedly attached to a mobile frame both in a direction parallel to the conveying direction, thanks to the support on the ground through rolling organs, and in an orthogonal direction with respect to the ground, thanks to a raising and lowering leverage which is articulated with it, and wherein at least the first actuating means of said leverage or the second actuating means of the translation of the frame with respect to the ground are supported by the frame itself.

Claims

1) A walking-beam conveyor (1) , comprising at least a fixed beam (2) extending in a direction parallel to the conveying direction (D) and at least a walking beam (5) extending on the side of and parallel to said fixed beam (2) , wherein said walking beam (5) is mobile with respect to said fixed beam (2) with an alternate motion component in an orthogonal direction with respect to the plane parallel to said beams between a lowered position and a raised position with respect to said fixed beam (2) and with an alternate, rectilinear motion component in a direction parallel to said conveying direction (D) between a first position and a second position, advanced with respect to the first one, said conveyor (1) being characterized in that it comprises :

- a mobile support frame (6) of said at least a walking beam (5) ,

- rolling organs (7) associated with said frame (6) for supporting the same on the ground (S) , rolling organs which are rotatable around an axis parallel to said plane and orthogonal to said conveying direction (D) ,

- a leverage (10) articulated to said frame (6) for raising and lowering the same with respect to the ground (S) and thus said walking beam (5) with respect to said fixed beam (2) ,

- first actuating means (11) of said leverage (10) for the alternate displacement of said frame (6) between a raised position and a lowered position with respect to the ground (S) and therefore for the alternate displacement of said walking beam (5) between said raised position and said lowered position and

- second actuating means (12) of said frame (6) in alternate rectilinear motion in a direction parallel to said conveying direction (D) for the alternate displacement of the same and, therefore, of said walking beam (5) between said first and second position.

2) The conveyor (1) according to claim 1, characterized in that at least one of said first actuating means (11) and said second actuating means (12) are supported by said frame (6) .

3) The conveyor (1) according to claim 1 or 2, characterized in that said first actuating means (11) are supported by said frame (6) and operatively connected to said leverage (10) , leaving free the displacement of said frame (6) in a direction parallel to said conveying direction (D) .

4) The conveyor (1) according to one or more preceding claims, characterized in that said second actuating means (12) are operatively connected between said frame (6) and the ground or a fixed wall, leaving free the raising and lowering displacement of said frame (6) .

5) The conveyor (1) according to one or more preceding claims, characterized in that said leverage

(10) comprises at least one pair of substantially L- shaped levers (13) , which at the angle of connection between the two arms of the L are hinged to said frame (6) in a rotary way around an articulation . axis (14) parallel to said plane and orthogonal to said conveying direction (D) and which have the upper end articulated with at least one transmission rod (15) in a rotary way around a respective articulation axis (16) parallel to said plane and orthogonal to said conveying direction (D) , and the lower end provided with a respective said rolling organ (7) , wherein said transmission rod (15) moves with a component parallel to said conveying direction (D) .

6) The conveyor (1) according to claim 5, characterized in that said leverage (10) comprises a plurality of said levers (13) distributed and mutually spaced along the extension of said frame (6) parallel to said conveying direction (D) , said transmission rod (15) comprising a train of rods (17) articulated two- by-two to a respective link-rod (18) to which the upper end of said respective lever (13) is articulated.

7) The conveyor (1) according to claim 5 or 6, characterized in that said first actuating means (11) are supported by said frame (6) and are operatively associated with said transmission rod (15) for actuating the same in said motion with a component parallel to said conveying direction (D) .

8) The conveyor (1) according to one or more claims from 5 to 7, characterized in that said first actuating means (11) comprise at least a first linear actuator (23) which has the opposite ends respectively hinged to said transmission rod (15) and to said frame (6) in a rotary way around a respective hinging axis (24, 25) parallel to said plane and orthogonal to said conveying direction (D) .

9) The conveyor (1) according to one or more claims from 5 to 8 , characterized in that said first actuating means (11) comprise first mechanical means for transmitting the rotary motion of a first shaft (30) , actuated in rotation by first motor means (31) , in a rectilinear alternated motion of said transmission rod (15) .

10) The conveyor (1) according to claim 9, characterized in that said first shaft (30) is supported by said frame (6) in a rotary way around an axis parallel to said plane and orthogonal to said conveying direction (D) .

11) The conveyor (1) according to claim 10, characterized in that said first transmitting mechanical means comprise a first disc (35) mounted eccentric on said first shaft (30) and fixedly attached to it in rotation, a first collar (36) inside which said first disc (35) is housed in a rotary way and which is defined at the end of a rod (37) the opposite end of which is articulated to said transmission rod (15) .

12) The conveyor (1) according to one or more claims from 9 to 11, characterized in that said first motor means (31) are constrained to the ground, a transmission shaft (33) being provided, the opposite ends of which are respectively associated with said first motor means (31) and which said first shaft (30) by means of respective articulated joints.

13) The conveyor (1) according to one or more preceding claims, characterized in that said second actuating means (12) comprise at least a second linear actuator (26) which has the opposite ends associated respectively with said frame (6) and with the ground (S) or with a fixed wall.

14) The conveyor (1) according to claim 13, characterized in that said second linear actuator (26) has at least one end associated with the ground (S) or with said fixed wall and that is hinged in a rotary way around a respective hinging axis (29) parallel to said plane and orthogonal to said conveying direction (D) .

15) The conveyor (1) according to claim 14, characterized in that said second linear actuator (26) is supported by said frame (6) .

16) The conveyor (1) according to one or more preceding claims, characterized in that said second actuating means (12) comprise second mechanical means for transforming the rotary motion of a second shaft (38) in an alternate rectilinear motion of said frame (6) , wherein said second shaft (38) is supported in a rotary way to the ground (S) and actuated in rotation by respective second motor means (40) .

17) The conveyor (1) according to claim 16, characterized in that said second mechanical transforming means comprise a second disc (43) which is mounted eccentric on said second shaft (38) and which is fixedly attached to it in rotation, said second shaft (38) extending in a direction parallel to said plane and orthogonal to said conveying direction (D) , a second collar (44) inside which said second disc (43) is housed in a rotary way and which is rigidly supported by a slide (45) and a guide body (46) which is rigidly supported by said frame (6) and along which said slide (45) is slidably driven in a direction orthogonal with respect to said plane.

18) The conveyor (1) according to one or more preceding claims, characterized in that said first actuating means (11) and said second actuating means (12) are selectively and alternatively active. 19) A furnace (100) comprising a treatment chamber (101) provided with an inlet (102) and an outlet (103) for the material to be treated and a conveyor (1) housed in said chamber for transporting said material from said inlet to said outlet, characterized in that said conveyor comprises a walking-beam conveyor according to one or more claims from 1 to 18.