EP0900760A2

EP0900760A2 - Device for the lifting and transportation of blocks of hollow pieces in sites with limited access space

Info

Publication number: EP0900760A2
Application number: EP98500154A
Authority: EP
Inventors: Joan C/O Forgestal S.L. Noguera Puig
Original assignee: Forgestal SL
Current assignee: Forgestal SL
Priority date: 1997-07-07
Filing date: 1998-07-03
Publication date: 1999-03-10
Also published as: ES2147085B1; ES2147085A1; EP0900760A3

Abstract

It comprises a plurality of lifting and transportation elements (30), constituted by two oblong, flexible elements (1, 2) facing each other and adapted to be introduced via their free end into the horizontal hollow channel of the lower piece of a block (10), each flexible, oblong element being movable longitudinally and curved by a supporter-curver device (3, 4) and being provided with an introduction and extraction device (5, 6) to force it to move through the supporter-curver device (3, 4). The assembly is supported in a base structure (7, 8) provided with vertical displacement movements (v) and horizontal displacement movements (h). The free end of the elements (13) supports the vertical bending stress produced by the weight of the block on lifting it.

Description

Technical Sector of the Invention.-

The present invention relates to a device for the lifting and transportation of blocks of hollow pieces insites with limited access space, applicable to the lifting and transportation of blocks of one Title or more pieces of which at least the lower is provided with at least one hollow, rectilinear, horizontal channel, which pierces it completely.
The device which is the object of the present invention is particularly applicable in the lifting and transportation of blocks of hollow pieces constituting the refractory of the base of the transportation trolleys of ceramic material in biscuit-firing or annealing kilns.

State of the Art.-

In different industrial sectors, among these heavy ceramics for construction, it is a common necessity to lift blocks formed of one or more layers of pieces of those of which at least the lowest has the shape of a more or less regular parallelepiped and consists of an assembly of partially hollow pieces, ordered in such a manner that within the layer there are created several, parallel, hollow, rectilinear channels which pierce it completely.
A variety of procedures and devices for the lifting of blocks of pieces are presently known. So, when the aforesaid blocks are placed in an isolated manner, or when the distance between two consecutive blocks allows, the procedure is known of lifting the blocks with pincers equipped with horizontal metal forks which, penetrating the hollow channels from one or both sides, allows the lifting of the block by supporting from below each one of the constituent pieces of its lower layer.
When the distance between two consecutive blocks is less than that which would allow the use of pincers with horizontal metal forks, but the lower layer is formed in the longitudinal direction by a single piece or several pieces of an appropriate shape and with a favorable height/ length ratio, the pincer system is known which, pressing the pieces of the lower layer, raises them by taking advantage of the friction of the vertical faces of the pincer and the vertical faces of the consecutive pieces.
In a known variant of the pressure pincers, applicable when the pieces of the lower layer do not have the appropriate shape and/ or there is an unfavorable height/length ratio but there are separations between the consecutive pieces, the pressure pincer action is carried out via inflatable or fixed tongues introduced within the separation spaces between the consecutive pieces.
However none of these procedures and devices are applicable in those cases in which the distance between consecutive blocks is less than that which would allow the use of pincers with horizontal forks, the pieces do not have the adequate shape and/ or there is an unfavorable height/ length ratio and there is no separation between contiguous pieces, which constitutes a drawback.
The aim of the present invention is to solve the aforementioned drawback arising if the known embodiments of pincers designed for the lifting of blocks of pieces.

Explanation of the Invention.-

The object of the present invention is a device for the lifting and transportation of blocks of hollow pieces in sites with limited access space, of a new structure and use, which in its essence is characterized in that it comprises a plurality of lifting and transportation elements, each one of which is constituted by a pair of equal, oblong, flexible elements, whose length is much greater than the dimensions of its transversal section, facing each other, placed on both sides of the block to be lifted and transported and being adapted to be introduced via their free end into the saidhorizontal, hollow, channel of the lower piece of the block, each flexible, oblong element being placed movably longitudinally by a supporter-curver device designed to give the flexible, oblong element a change of direction, in such a manner that the direction of the part of the flexible, oblong element introduced into the supporter-curver forms an angle with the part introduced into the hollow, horizontal channel of the lower piece of the block, each flexible, oblong element being provided with an introduction and extraction device adapted to act upon the opposite end to that of the introduction in the channel of the lower piece of the block and force it to move through the supporter-curver device, in both directions, of introduction and extraction of its free end of the piece, the entirety of flexible, oblong elements, supporter-curver devices and introduction and extraction devices being sustained in a base structure provided with a vertical displacement movement and a horizontal displacement movement, all this in such a manner that the end part of the oblong elements destined to be introduced into the horizontal channel of the lower piece of the block has a resistance to bending such that, together with the other oblong elements of the device, it can support the vertical bending stress produced by the weight of the block on lifting it.
This allows the external space occupied by the flexible oblong elements outside of the block of hollow pieces to be notably less, in the direction parallel to the channels, to the length of the part of the said flexible oblong elements introduced into the said channels.
According to one embodiment of the present invention, each flexible, oblong element is constituted by a flat metal strip.
In accordance with another embodiment of the device object of the present invention, each flexible oblong element is constituted by a metal strip of a sensibly curved cross-section.
According to another embodiment of the device of the invention, each flexible, oblong element is constituted by a sheaf of metal strips joined together at one end thereof.
In accordance with another embodiment of the device of the invention, each flexible, oblong element is constituted by a sheaf of metal strips joined together at their two ends.
According to another embodiment of the device of the invention, each flexible, oblong element is constituted by a helical spring of contiguous spires, provided on the inside with a tubular chamber, inflatable in a diametrical direction and un-extendable in a longitudinal direction, adapted to be introduced un-inflated into the hollow, horizontal channel of the lower piece of the block and to be inflated once inside, in such a manner that the helical spring supports the forces of compression and the inflated, tubular chamber supports the tensional stresses associated with the bending of the whole. In accordance with another embodiment of the device of the invention, each flexible, oblong element is constituted by a tubular chamber, inflatable in a diametrical direction and un-extendable in a longitudinal direction, reinforced with strings or wires which tend to maintain its free end rigid, the said chamber being given such a configuration that it is introduced un-inflated into horizontal channel of the lower piece of the block and, once inflated, is compressed against the walls of the horizontal channel of the piece of the block and forms an element resistant to vertical bending, in such a manner that the pieces support the tensional stresses associated with the bending of the whole.
In accordance with another embodiment of the device object of the present invention, each flexible oblong element is constituted by a metal strip which on its lower face is provided with a series of rigid pieces, contiguous and tilting, in such a manner that the element can be curved easily in one direction by the supporter-curver device, but in the opposite direction it is capable of resisting extreme bending stresses, the metal strip supporting the tensional stresses, whilst the rigid pieces support the compression stresses associated with the bending of the whole.
According to another embodiment of the device of the invention, the supporter-curver device is constituted by a guide of a transversal cross-section adapted to that of the flexible oblong element, provided with a curved central portion and one or two rectilinear portions.
In accordance with another embodiment of the device of the invention, the supporter-curver device is constituted by an assembly of roller pairs perpendicular to the curvature plane of the flexible oblong element and of a generatrix adapted to the shape of the flexible oblong element, provided with a curved central portion and one or two rectilinear portions.
According to another embodiment of the device of the invention, the introduction-extraction device is constituted by a hydraulic or pneumatic cylinder, which acts on the end of the flexible, oblong element opposite to that of the introduction in the channel of the block and which is capable of giving to the flexible, oblong element an alternative rectilinear movement.
In accordance with another embodiment of the device according to the invention, the introduction -extraction device is constituted by a nut and screw mechanism, which acts upon the end of the flexible oblong element opposite to that of the introduction in the channel of the block and which is capable of giving to the flexible, oblong element an alternative rectilinear movement.
In accordance with a further embodiment of the device according to the invention, the introduction -extraction device is constituted by a revolving arm, which acts upon the end of the flexible oblong element opposite to that of the introduction in the channel of the block and which is capable of giving to the flexible, oblong element an alternative circular arc movement.
According to a yet further embodiment of the device of the invention, each oblong element is constituted by a group of one or more upper metal strips, whose free end is bent down and inwards in a final end portion finished in a check; by a group of one or more lower metal strips; and by a flexible separator element placed between both groups of upper and lower metal strips, all this in such a manner that the introduction-extraction device gives to the group oflower metal strips a longitudinal displacement movement with respect to the group of upper metal strips, so that in the initial rest position, the outer end of the group of lower metal strips is separated from the end check wall of the final position of the group of upper metal strips, whilst at the end of the introduction movement, the free end of the lower group of metal strips is placed contiguous to the saidend check wall.
In a first variant of this last embodiment, the flexible separator element is constituted by an essentially uniform block, and preferably continuous.
In a second variant of this last embodiment, the flexible separator element is constituted by at least one block and by at least one pair of complementary hooks facing each other, respectively attached to the upper and lower groups of metal strips and adapted to mutually hook each other in the introduction movement final position of the introduction/ extraction device.
In a third alternative variant, the flexible separator element is constituted by at least one block and by at least one pair of complementary magnets facing each other, respectively attached to the upper and lower groups of metal strips and adapted to be contiguous and superimposed, in a placement of mutual attraction in the introduction movement final position of the introduction/ extraction device.
It must be understood that combining among them the different possible practical embodiments of the said flexible, oblong elements 1,2, of the said the supporter- curver devices 3,4 and of the said introduction- extraction devices 5, 6, the present invention allows the coverage of practically the whole wide range of possible combinations which are actually present presented in practice among the dimensions (length, width, height) of the blocks, the distance between two consecutive blocks and the shape and dimensions of the longitudinal channels.

Brief Description of the Drawings.-

Following there will be a description of the preferred, although not exclusive embodiments, of the device of the present invention, for which better comprehension are attached some drawings, given merely as a as an illustrative example, in which:
Figs. 1 to 6 show three embodiments of known devices oflifting and transportation, illustrative of the present state of the art;
Figs. 7 to 28 illustrate several schematic views which show different embodiments of the flexible oblong element according to the present invention;
Figs. 29 to 32 are schematic front elevation views, which illustrate two embodiments of the supporter-curver device according to the present invention;
Figs 33 to 36 are respective schematic front elevation views which illustrate two embodiments of the introduction/ extraction device according to the present invention;
Fig. 37 is a schematic front elevation view, which illustrates one embodiment of the entirety of the device in question,
Figs. 38 and 39 are each schematic views of a last embodiment of the device of the present invention, according to a first variant;
Figs. 40 and 41 are two schematic views of the said last embodiment of the device of the present invention, although according to a second variant; and
Figs. 40 and 41 are another two schematic views of the said last embodiment of the device of the present invention, although according to a third variant.

Detailed description of the drawings.-

In figs. 1 and 2 is illustrated a first embodiment of a device for the lifting and transportation of blocks 11 of hollow pieces 10 in sites known in the present state of the art, consisting of lifting the blocks 11 with pincers 31 equipped with horizontal metal forks 32. The forks 32 penetrate the hollow channels 11, as is shown in fig. 2, from one or both sides, which allows the lifting of the block 11, sustaining from below the pieces 10' constituting the lower layer of the same.
This first embodiment is to be used in the cases in which the blocks 11 are placed in an isolated manner, or if the distance between two consecutive blocks 11 allows.
In figs. 3 and 4 is illustrated a second embodiment of a device for the lifting and transportation of blocks 11 of hollow pieces 10' in sites known in the present state of the art, consisting of employing pressure pincers 33 which press the pieces 10' of the lower layer and raise them by the friction action between the vertical faces of the pieces 10, as well as between the vertical faces of the consecutive pieces 10.
This second embodiment is employed when the distance between two consecutive blocks 11 is less than that which would allow the use of pincers 31 with horizontal metal forks 32 according to the first embodiment of figs. 1 and 2, and the lower layer is formed in the longitudinal direction by a single piece 10 or by several pieces 10 of an appropriate shape and favorable height/ length ratio.
In figs. 5 and 6 is illustrated a third embodiment of a device for the lifting and transportation of blocks 11 of hollow pieces 10' in sites known in the present state of the art, which is a variant of the second embodiment and which comprises fixed or inflatable tongues 34 which, introduced in the separation spaces between contiguous pieces 10, collaborate in the action of the pressure pincers 33.
As has been said, this variant is particularly applicable when the pieces 10' of the lower layer of the block 11 do not have the appropriate shape and/ or an unfavorable height/length relationship but there are separations between the consecutive pieces 10.
In fig. 37 can be seen that the device for the lifting and transportation of blocks 11 of hollow pieces 10' in sites with limited access space, is constituted by a plurality of lifting and transportation elements 30, placed on both sides of a series of blocks 11 of hollow pieces 10 which advance one after the others on, for example, transportation trolleys in ceramic kilns, in the longitudinal direction of the kiln. In favor of a greater clarity, in the drawings the kiln and the trolley have been omitted.
The number of the said lifting and transportation elements 30 to be used in each particular case will vary with the dimensions, number and placement form of the blocks 11 and of the hollow pieces 10 within the same, as well as with the longitudinal distance to be covered by the device of the present invention.
In figs. 7 to 37 it can be seen that each one of the said lifting and transportation elements 30 according to the present invention is composed of flexible, oblong elements 1, 2, of a supporter-curver device 3, 4, associated with each one of the flexible, oblong elements 1, 2, and of an introduction/ extraction device 5, 6, of the flexible, oblong elements 1, 2, for each one of these last.
The flexible, oblong elements 1, 2, the supporter-curver devices 3, 4, and the introduction/ extraction devices 5, 6 are supported on a base structure 7, 8 of the same, movable in its turn in vertical and longitudinal directions with respect to a main structure 9 fixed to the kiln in question.
The number of flexible, oblong elements 1, 2 to employ in each individual application, will be that appropriate to the number of channels 22 of blocks 11 to lift and will determine at the same time the number of lifting and transportation elements 30.
The supporter-curver devices 3, 4 are in equal number to those of the flexible, oblong elements 1, 2 and are destined to create in these last a change of direction, in such a manner that the direction of the rectilinear portion 26 outside the block 11 can form an angle with the direction of its substantially horizontal, rectilinear portion 25 introduced in the channels 12 of the blocks 11. In these circumstances, the rectilinear portion 25 of the oblong elements introduced within the channels of the block can support the bending stress transmitted by the block 11 on being lifted.
The introduction/ extraction devices 6, 7 act upon one end of the flexible, oblong elements 1, 2 and displace them through their respective supporter-curver devices 3, 4, in the direction of their introduction into the channels 12 of the blocks 11, and in the opposite direction for their extraction from the same.
The base structure 7, 8 is provided with the vertical component movements adequate for the lifting of the blocks 11, as well as the horizontal component movements adequate for the horizontal transportation of the same.
Owing to the diversity of possible combinations which are presented in real practice between the dimensions (length, width, height) of the blocks 11, the distance between two consecutive blocks 11 and the shape and dimension of the longitudinal channels 12 of the hollow pieces 10, in the present invention has been foreseen different embodiments of the flexible oblong elements 1, 2, of the supporter-curver devices 3, 4, and of the introduction/ extraction devices 5, 6, in such a manner that, combined among themselves it is possible to obtain the most appropriate form for each one of the said possible combinations.
Some of the foreseen possible embodiments of the flexible oblong element 1, 2 are those in which:

the flexible, oblong elements 1, 2 are constituted by a flat metal strip 14 (figs. 7 and 8); the flexible, oblong elements 1, 2 are constituted by a metal strip of a notably curved transversal section 15 (figs. 9 and10);
the flexible, oblong elements 1, 2 are constituted by a sheaf of metal strips joined together at one of their ends 17 (figs. 11, 12, 15, 16, 19 and 20);
the flexible, oblong elements 1, 2 are constituted by a sheaf 16 of metal strips joined together at their two ends 17, 18 (figs. 13, 14, 17, 19, 21 and 22);
the flexible, oblong elements 1, 2 are constituted by a helical spring 19 of contiguous spires, provided on the inside with a tubular chamber 20, inflatable in a diametrical direction and un-extendable in a longitudinal direction, adapted to be introduced un-inflated into the hollow,horizontal channel 12 of the lower piece 10' of the block 11 and to be inflated once inside, in such a manner that the helical spring 19 supports the forces of compression and the inflated, tubular chamber 20 supports the tensional stresses associated with the bending of the whole. (Figs. 23 and 24) ;
the flexible, oblong elements 1, 2 are constituted by a tubular chamber 20, inflatable in a diametrical direction and un-extendable in a longitudinal direction, reinforced with strings or wires 21 which tend to maintain its free end rigid, the said chamber 20 being given such a configuration that it is introduced un-inflated into horizontal channel 12 of the lower piece 10' of the block 12 and, once inflated, is compressed against the walls of the horizontal channel 12 of the piece 10' of the block 12 and forms an element resistant to vertical bending, in such a manner that the pieces 10 support the tensional stresses associated with the bending of the whole (figs. 25 and 26);
the flexible, oblong elements 1, 2 are constituted by a metal strip 14 which on its lower face is provided with a series of rigid pieces 22, contiguous and tilting, in such a manner that the element 1, 2 can be curved easily in one direction by the supporter-curver device, but in the opposite direction it is capable of resisting extreme bending stresses, the metal strip 14 supporting the tensional stresses, whilst the rigid pieces 10 support the compression stresses associated with the bending of the whole (figs. 27 and 28); and
the flexible, oblong elements 1, 2 are constituted by a group of one or more upper metal strips 35, whose free end is bent down and inwards in a final end portion finished in a check 36; by a group of one or more lower metal strips 37; and by a flexible separator element 40 placed between both groups of upper and lower metal strips, all this in such a manner that the introduction- extraction device 5, 6 gives to the group of lower metal strips a longitudinal displacement movement with respect to the group of upper metal strips, so that in the initial rest position, the outer end 38 of the group of lower metal strips is separated from the end check wall 39 of the final position of the group of upper metal strips, whilst at the end of the introduction movement, the free end of the lower group of metal strips is placed contiguous to the said end check wall. (figs. 38 to 43)

According to a variant of this last embodiment, shown in figs. 38 and 39, the flexible separator element 40 is constituted by an essentially uniform and preferably continuous block.
According to a variant of this last embodiment, shown infigs. 40 and 41, the flexible separator element 40 is constituted by at least one block 41 and by at least one pairof complementary hooks 42, 43 facing each other, respectivelyattached to the upper and lower groups of metal strips 35, 37. The hooks 42, 43 of each pair, which can optionally be placed in cavities within the blocks 41, hook one into the other in the final position of the introduction movement of the introduction/ extraction device 5, 6.
In figs. 42 and 43 is shown a third possible variant of conformation of the flexible separator elements 40 of the last generic embodiment, in which they are equally constituted by at least one block 41 and by at least one pair of complementary magnets 44, 45 facing each other, respectively attached to the upper and lower groups of metal strips 35, 37. These last are contiguous and superimposed, in a placement of mutual attraction in the introduction movement final position of the introduction/ extraction device 5, 6.
Some of the foreseen possible embodiments of the supporter-curver device 3, 4 are those in which:

the supporter-curver device 3, 4 is constituted by a guide 23 of a transversal cross-section adapted to that of the flexible oblong element 1,2, provided with a curved central portion 24 and one or two rectilinear portions 25,26. (Figs. 29 and 30); and
the supporter-curver device 3, 4 is constituted by an assembly of pairs of rollers 27 of perpendicular axis to the curvature plane of the flexible oblong element 1,2, and of a generatrix adapted to the shape of the latter, provided with a curved central portion 24 and one or two rectilinear portions 25, 26. (Figs. 31 and 32).

Some of the foreseen possible embodiments of the introduction- extraction device 5, 6 are those in which:

the introduction- extraction device 5, 6 is constituted by a hydraulic or pneumatic cylinder 28, which acts on the end of the flexible, oblong element 1,2 opposite to that of the introduction in the channel 12 of the block 11 and which is capable of giving to the flexible, oblong element 1,2 an alternative rectilinear movement. (Figs. 33 and 34);
the introduction- extraction device 5, 6 is constituted by a nut and screw mechanism, which acts upon the end of the flexible oblong element 1,2 opposite to that of the introduction in the channel 12 of the block 11 and which is capable of giving to the flexible, oblong element 1,2 an alternative rectilinear movement, this embodiment not being shown in the drawings; and
the introduction- extraction device 5, 6 is constituted by a revolving arm 29, which acts upon the end of the flexible oblong element 1,2 opposite to that of the introduction in the channel 12 of the block 11 and which is capable of giving to the flexible, oblong element 1,2 an alternative circular arc movement. (Figs. 35 and 36).

The nature of the invention being sufficiently described, as well as the manner of putting it into practice, it is here declared that inasmuch as the fundamental principal is not altered, changed or modified, it may undergo minor changes, it being the essence for which the patent of invention is applied for twenty years, which is summarized in the following claims. In particular, it is important to note that the device which is here dealt with could function perfectly with oblong elements 1, 2 placed on only one of the sides of the block 11 to be lifted and transported, in the case that the weight of this last allowed it. However, that would not be more than an imperfect solution to the problem that the device of the present invention resolves, this being a solution which moreover is clearly comprised within the scope of the invention.

Claims

A device for the lifting and transportation of blocks of hollow pieces (10) in sites with limited access space, applicable to the lifting and transportation of blocks (11) of one or more pieces of which at least the lower (10') is provided with at least one hollow, rectilinear, horizontal channel (12), which pierces it completely, characterized in that it comprises a plurality of lifting and transportation elements (30), each one of which is constituted by a pair of equal, oblong, flexible elements (1, 2), whose length is much greater than the dimensions of its transversal section, facing each other, placed on both sides of the block to be lifted and transported and being adapted to be introduced via their free end into the said horizontal, hollow, channel of the lower piece of the block, each flexible, oblong element being placed movably longitudinally by a supporter-curver device (3, 4) designed to give the flexible, oblong element (1, 2) a change of direction, in such a manner that the direction of the part of the flexible, oblong element introduced into the supporter-curver forms an angle with the part introduced into the hollow, horizontal channel (12) of the lower piece (10') of the block (11), each flexible, oblong element being provided with an introduction and extraction device adapted to act upon the opposite end to that of the introduction in the channel of the lower piece of the block and force it to move through the supporter-curver device (3, 4), in both directions, of introduction and extraction of its free end of the piece, the entirety of flexible, oblong elements (1, 2), supporter-curver devices (3, 4) and introduction and extraction devices (5, 6) being sustained in a base structure (7, 8) provided with a vertical displacement movement (v) and a horizontal displacement movement (h), all this in such a manner that the end part of the oblong elements (13) destined to be introduced into the horizontal channel (12) of the lower piece (10') of the block (11) has a resistance to bending such that, together with the other flexible, oblong elements (1, 2) of the device, it can support the vertical bending stress produced by the weight of the block on lifting it.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that each flexible, oblong element (1, 2) is constituted by a flat metal strip (14).
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that each flexible, oblong element (1, 2) is constituted by a metal strip of a sensibly curved cross- section (15).
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that each flexible, oblong element (1, 2) is constituted by a sheaf of metal strips (16) joined together at one end (17) thereof.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that each flexible, oblong element (1, 2) is constituted by a sheaf of metal strips (16) joined together at their two ends (17, 18).
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that each flexible, oblong element (1, 2) is constituted by a helical spring (19) of contiguous spires, provided on the inside thereof with a tubular chamber (20), inflatable in a diametrical direction and un-extendable in a longitudinal direction, adapted to be introduced un-inflated into the hollow, horizontal channel (12) of the lower piece (10') of the block (11) and to be inflated once inside, whereby the helical spring supports the forces of compression and the inflated, tubular chamber supports the tensional stresses associated with the bending of the whole.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that each flexible, oblong element (1, 2) is constituted by a tubular chamber (20), inflatable in a diametrical direction and un-extendable in a longitudinal direction, reinforced with strings or wires (21) which tend to maintain its free end rigid, the said chamber being given such a configuration that it is introduced un-inflated into the horizontal channel (12) of the lower piece (10') of the block (11) and, once inflated, is compressed against the walls of the horizontal channel of the piece of the block and forms an element resistant to vertical bending, in such a manner that the pieces support the tensional stresses associated with the bending of the whole.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that each flexible oblong element (1, 2) is constituted by a metal strip (14) which on its lower face is provided with a series of rigid pieces (22), contiguous and tilting, in such a manner that the element can be curved easily in one direction by the supporter-curver device (3, 4), but in the opposite direction it is capable of resisting extreme bending stresses, the metal strip supporting the tensional stresses, whilst the rigid pieces (10) support the compression stresses associated with the bending of the whole.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that the supporter-curver device (3, 4) is constituted by a guide (23) of a transversal cross-section adapted to that of the flexible oblong element (1, 2), provided with a curved central portion (24) and one or two rectilinear portions (25, 26).
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that the supporter-curver device (3, 4) is constituted by an assembly of pairs of rollers (27) perpendicular to the curvature plane of the flexible oblong element (1, 2) and having a generatrix adapted to the shape of the flexible oblong element, provided with a curved central portion (24) and one or two rectilinear portions (25, 26).
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that the introduction-extraction device (5,6) is constituted by a hydraulic or pneumatic cylinder (28), which acts on the end of the flexible, oblong element (1, 2) opposite to that of the introduction in the channel (12) of the block (10') and which is capable of giving to the flexible, oblong element an alternative rectilinear movement.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that the introduction-extraction device (5, 6) is constituted by a nut and screw mechanism, which acts upon the end of the flexible oblong element (1, 2) opposite to that of the introduction in the channel (12) of the block (10') and which is capable of giving to the flexible, oblong element an alternative rectilinear movement.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that the introduction-extraction device (5, 6) is constituted by a revolving arm (29), which acts upon the end of the flexible oblong element (1, 2) opposite to that of the introduction in the channel (12) of the block (10') and which is capable of giving to the flexible, oblong element an alternative circular arc movement.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 1, characterized in that each oblong element (1, 2) is constituted by a group of one or more upper metal strips (35), whose free end is bent down and inwards in a final end portion (36) finished in a check; by a group of one or more lower metal strips (37); and by a flexible separator element (40) placed between both groups of upper and lower metal strips, all this in such a manner that the introduction- extraction device (5, 6) gives to the group of lower metal strips a longitudinal displacement movement with respect to the group of upper metal strips, so that in the initial rest position, the outer end (38) of the group of lower metal strips is separated from the end check wall (39) of the final position of the group of upper metal strips, whilst at the end of the introduction movement, the free end of the lower group of metal strips is placed contiguous to the said end check wall.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 14, characterized in that the flexible separator element (40) is an essentially uniform block, and preferably continuous.
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 14, characterized in that the flexible separator element (40) is constituted by at least one block (41) and by at least one pair of complementary hooks (42, 43) facing each other, respectively attached to the upper and lower groups of metal strips (35, 37) and adapted to mutually hook each other inthe introduction movement final position of the introduction/extraction device (5, 6).
A device for the lifting and transportation of blocks of hollow pieces (10) according to Claim 14, characterized in that the flexible separator element (40) is constituted by at least one block (41) and by at least one pair of complementary magnets (44, 45) facing each other, respectively attached to the upper and lower groups of metal strips (35, 37) and adapted to be contiguous and superimposed, in a placement of mutual attraction in the introduction movement final position of the introduction/extraction device (5, 6).