GB2231019A

GB2231019A - Production of extruded roof tiles using cassettes

Info

Publication number: GB2231019A
Application number: GB9008964A
Authority: GB
Inventors: Manfred Bracht; Lothar Hartenstein
Original assignee: Keller GmbH
Current assignee: Keller GmbH
Priority date: 1989-04-20
Filing date: 1990-04-20
Publication date: 1990-11-07
Anticipated expiration: 2010-04-20
Also published as: GB2231019B; GB9008964D0; DD300640A5; FR2646121A1; DK97690D0; DK97690A; FR2646121B1

Abstract

In the production of extruded roof tiles each "green" extruded roof-tile moulding (1) severed from the clay extrusion is transferred directly onto a plurality of parallel conveyor bands (3) which engage under it and convey it to and deposit it on a cassette (2). The extruded roof-tile mouldings (1) are preferably moved on a path with low inclination which intersects the path of movement of the cassettes, and the cassettes (2) are equipped on the top side with upwardly open conveyor-band passages allowing a penetration of the moulding conveyor (3) into the cassette (2) and a displacement of the cassettes under the conveyor-band. The conveyors (3, 4) for the extruded roof-tile mouldings (1) and the cassettes (2) are driven synchronously in terms of speed, and preferably their movement (as well as the cutting-off of the mouldings) is controlled as a function of the movement of the clay extrusion. <IMAGE>

Description

Process for producing extruded roof tiles with the use of cassettes and cassette for carrying out the process.

Description The invention relates to a process for producing extruded roof tiles, in which the extruded roof-tile mouldings are laid on so-called cassettes and are guided on these through a drier and kiln, and to cassettes for carrying out the process.

The abovementioned process has become known both in practice and, for example, from European Patent Specification 0,162,153. Although the process fundamentally affords benefits and the so-called H-cassettes are in many instances advantageous, there is still the disadvantage that the so-called "green", that is to say, still damp (undried) mouldings, immediately after being pressed, are deposited on the cassettes by means of suction grippers. For the depositing operation it is necessary to have an additional gripping station which grasps the extruded roof-tile moulding on its subsequent visible side.Since the suction gripper grips the freshly pressed moulding and has to hold it during the entire loading operation, relatively high suction forces are required, and this can therefore result in surface deformation, particularly a suction-gripper imprint, on the subsequent visible side of the roof tile.

Besides impairing the visual appearance of the extruded roof tiles, there is also the disadvantage of an additional cost-increasing appliance/device for the "production line" of the extruded roof-tile manufacture.

Moreover, it is especially disadvantageous that it is not possible to produce glazed or sanded extruded roof tiles.

The object on which the invention is based is, therefore, to provide a simpler process for producing extruded roof tiles, in which disadvantageous markings of the visible side do not occur. There will be provided, furthermore, a cassette which allows the process to be carried out and which permits cassette loading free of gripping means, if appropriate also automatic/mechanical cassette unloading, by simple means.

According to the invention, the process is achieved by means of the features of Patent Claim 1 and the cassette by means of the features of Patent Claim 11.

Further advantageous embodiments of the invention are to be taken from the remaining subclaims.

In the process according to the invention, the extruded roof-tile mouldings, still undried and therefore to some extent deformable, are laid directly free of gripping means, that i;s to say without an additional gripping device, onto the transport means carrying out the transport away from the cutting station. The surface forming the subsequent visible side of the roof tile thus remains untouched. As a result of the direct loading of the transferring moulding conveyor, a) undesirable gripper imprints on the finished product are avoided, b) it becomes possible to carry out a glazing or vitrifying of roof tiles which is undamaged and free of defects on the visible side, c) an efficient and cost-saving mode of operation is obtained.

Since the moulding conveyor picking up the extruded roof-tile mouldings as early as in the region of the cutting station also takes over the cassette loading, an especially simple and compact apparatus design (with a short constructional length between the moulding press and cassette-loading station) is also provided. The efficient cassette loading and, in the reverse order, cassette unloading are possible by means of the cassette which is intrinsically of extremely simple design and which, on the one hand, allows the conveyor band to penetrate into the cassette form and, on the other hand, permits the displacement of the cassettes relative to the conveyor transporting the mouldings and itself carrying out the loading operation (or, at an unloading station, the unloading operation).

Moreover, because of the perforations allowing the conveyor band to penetrate from above and located in the cassette wall (walling), the so-called "cassette web", carrying the extruded roof-ttle moulding to be dried and baked, there are large air orifices which allow a good supply of air to the deposited moulding, this in the end also having an advantageous influence on the drying process.

An exemplary embodiment (with two versions of the cassette conveyance) is illustrated diagrammatically in the drawings and explained in detail below. In the drawings: Fig. 1 shows a side view of the transfer station, in which the green, (still undried) extruded roof tile mouldings are laid mechanically onto cassettes for the drying and baking process, in the "cassette-loading" working position (cassette unloading takes place with a reversed conveyor rotation), Fig. 2 shows a side view of the transfer station corresponding essentially to that of Fig. 1, in which however the cassettes are laid not directly on the cassette conveyor, but on distance-deter mining auxiliary pallets carried by the conveyor, Fig. 3 shows a cross-section through a cassette according to the invention, with an extruded roof-tile moulding represented by dot-and-dash lines and with an indicated moulding transport path having preferably three conveyor bands, according to the sectional line III-III of Fig.

4, Fig. 4 shows a top view of a part region of a cassette according to the invention, a laid-on extruded roof-tile moulding being represented by dot-and dash lines, and Fig. 5 shows an end view of two cassettes stacked one above the other with extruded roof-tile mouldings represented by dot-and-dash lines.

In the process according to the invention for producing extruded roof tiles, the undried moulding of which is designated by 1, cassettes denoted by 2 and consisting of refractory material are used as a carrier (base) for the drying and baking process and allow loading and unloading free of gripping means, so that undesirable gripper imprints on the visible side of the roof tile are avoided on the finished product and there is no need for gripper devices equipped with suction grippers, as has been customary hitherto, in the production system.

According to the invention, each "green" extruded roof-tile moulding 1 severed from the clay extrusion and spaced is transferred directly onto a conveyor (moulding conveyor) 3 which engages under it and which conveys it further to a loading station, which can extend especially at a relatively short distance from the cutting station and where this extruded roof-tile moulding 1 is laid automatically and mechanically, in particular by means of the conveyor 3 carrying it, onto a cassette 2 advanced/delivered by means of a conveyor (cassette conveyor) 4. The moulding conveyor 3 is composed of at least two, preferably 3 conveyor bands 3a, 3b, 3c running in parallel and at a distance next to one another, a version with so-called "knife bands", in which the lower deflection is of an especially small size, being particularly preferred.

To allow the automatic loading and/or unloading of a cassette 2 in a simple way, that is to say to make the corresponding device/appliance simple and costeffective, the cassette 2 is preferably and advantageously designed in such a way that the conveyor bands 3a, 3b, 3c, which engage under the extruded roof-tile mouldings 1 and which rotate with their carrying strand at a small acute angle (of less than 30', especially approximately 3-20) relative to the path of movement of the cassettes, penetrate into the cassettes 2 from above and the cassettes 2 can be moved under the conveyor 3 loading (or unloading) them, that is to say moved past the lower deflection located on the same side as the cassettes without any danger of collision.

For the purpose of an efficient mode of operation, it can be advantageous to design the cassette or cassettes 2 in such a way that a plurality of extruded roof-tile mouldings 1 can be received at a distance (as an air passage in the drying and/or baking process) X or X'. In a preferred way, there is provision for receiving two extruded roof-tile mouldings 1 lying spaced behind one another (see the graphic representation).

The cassettes 2 are designed in the manner of a so-called "H-cassette" and at all events have a supporting surface which is arranged at a distance from the standing plane and which can be made air-permeable, preferably being designed so as to guarantee the support of the moulding at particular points and a good air circulation round the extruded roof-tile mouldings 1 located on a cassette 2.

The basic form (in longitudinal section or in cross-section) of the cassette 2 can differ from the Hform mentioned. It is sufficient to have a design in the form of an upside-down "U", accordingly a basic form resembling that of an "n". It is important only to have such a large free space between the moulding laying-on support and cassette standing plane that the conveyorband deflecting members 3d located on the same side as the cassettes (that is to say the lower) are received (accommodated) in terms of their height.

Irrespective of the particular basic cassette form used (especially in its longitudinal section), the cassette 2 must be designed so that it is easily possible to stack cassettes 2 in a state occupied by mouldings.

As seen in vertical section, preferably in vertical longitudinal section, the cassette 2 possesses, in the two end regions, standing elements 5 which act as stands and which are each formed by a continuous walling (cassette end walling) or by at least two spar-like legs.

The design with end standing walls 5 which can be seen especially in Figs. 3-5 viewed together is especially simple, stable and preferred. At the same time, these standing walls (cassette end walls 5) can have a basic form narrowing towards the bottom, especially a basic trapezoidal form. To allow a positionally stable and/or collision-free stacking of the cassettes 2, the lower edges of the two standing walls 5 are recessed in the middle region, so that in each case two standing surfaces (four standing surfaces provided in the respective corner regions on each cassette 2) are obtained.

The supporting wall (walling) of the cassette 2 serving for the support of the roof-tile moulding is designated by 6 and is of grid-like design. Thus, it has at least two, preferably 3 conveyor-band passages 7 which allow the penetration of the conveyor bands 3a, 3b, 3c carrying the extruded roof-tile mouldings 1 and the relative displacement between the cassette 2 and those ends (deflections) of the conveyor bands 3a, 3b, 3c located on the same side as the cassettes. Preferably, the cassette supporting wall (walling) 6 is formed by a grid with grid bars extending in the longitudinal direction of the cassette, the inner, (middle) grid bars 6a laterally limiting the conveyor-band passages (conveyorband passage orifices) 7 extending in the laying-on direction of the roof-tile mouldings 1.The conveyor-band passages 7 are each formed on the one hand, that is to say between the grid bars/grid webs 6a, by an interstice designated by 7a and on the other hand, that is to say in the region of the cassettes standing walls 5, by an upwardly open clearance 7b (especially of U-like basic form); see Figs. 3 to 5. As seen in an end view, the result is therefore a U-shaped groove which makes it possible, when the moulding conveyor 3 has penetrated into the cross-sectional cassette profile, to displace the cassette 2 over the entire cassette length under the conveyor ends (conveyor-band deflections) located on the same side as the cassettes.

To guarantee good air circulation round laid-on extruded roof-tile mouldings 1, the cassette 2 is equipped, on the top side, with bosses 8, 9, thereby ensuring a laying-on at particular points (locations).

These bosses 8, 9 are arranged on the top sides of the grid bars. Their supporting surfaces (top surfaces) are matched to the form of the underside of the extruded roof tiles, that is to say, in a roof-tile design of arcuate profile, the hoss top surfaces likewise lie on an arc, as seen in the cassette cross-section, so that a perfect moulding support is guaranteed and the intrinsically still deformable "green" extruded roof-tile mouldings 1 cannot experience deformation. In an especially preferred embodiment, the cassette grid bars forming the laying-on support for the roof-tile mouldings are themselves in one plane, especially parallel to the standing plane of the cassette 2.

The process according to the invention, especially the mode of operation of the cassette loading without the aid of a suction gripper or the like grasping the particular extruded roof tile 1 on its subsequent visible side, can be seen in an easily understandable way in Fig. 1 (as regards the process free of auxiliary pallets) or in Fig. 2 (as regards the process with auxiliary pallets 10). In these, the movement cycle is clearly represented by the arrows A, B and C.Arrow "A" indicates the general "loading" direction of conveyance, arrow "B" shows the relevant direction of rotation of the cassette conveyor 4, and arrow "C" shows the relevant direction of rotation of the moulding conveyor 3 (formed by at least 2, preferably 3 conveying elements, especially knife bands, which are arranged at a lateral distance next to one another and the height of which is matched to the form of the extruded roof tiles - Fig. 3).

The unloading of the extruded roof tiles from a cassette 2 takes place in the opposite direction, that is to say with a conveyor rotation taking place in the opposite direction to the arrows B and C.

To guarantee a perfect positioning of the extruded roof-tile mouldings 1 on the respective cassettes 2, there is a switching arrangement, in which the movement of a) a cut-off device, so-called cut-off table, b) the moulding conveyor 3 which conveys the "green" extruded roof-tile mouldings 1 cut off, preferably cut off and brought to a distance/spacing X or X' from one another, away from the cutting station and which carries out the cassette loading, c) the cassette conveyor 4 delivering the cassettes 2 to the roof-tile loading point is controlled synchronously as a function of the movement of the clay extrusion.

Preferably, two extruded roof-tile mouldings 1 are simultaneously severed from the clay extrusion and thereafter brought to a distance from one another/spaced.

The cutting off is carried out by means of a horizontally displaceable cutting table (not shown) moveable to and fro and having vertically moveable cutting elements, and the just cut-off mouldings (extruded roof tiles) 1 are brought to a distance from one another or spaced as a function of the "advance" and "return of the cutting table. The spacing X or X' is obtained during (that is to say, as a result of) the cutting-table return and the spacing Y or Y' is obtained during (that is to say, as a result of) the cutting-table advance.

The cut-off and spaced extruded roof-tile mouldings 1 are continuously transferred, behind the cutting table in their direction of movement "A", directly onto the transport path consisting of the conveyor 3 and delivered by the upper strand of the conveyor, on an oblique path intersecting the horizontal path of movement of the cassettes, to the cassette 2 to be loaded and are deposited by means of this onto the respective cassette 2. The mutual distances are uniform, since the cassettes 2 and extruded roof-tile mouldings 1 run synchronously in terms of speed. The transfer onto the cassettes 2 takes place gradually, since the obliquely arranged moulding transport path enters recesses 7 of the cassette or cassettes 2 and intersects the path of movement of the cassettes (that is to say, crosses it at a low inclination). The cassettes 2 are delivered continuously and, depending on the type of automatic delivery mechanism, lie on auxiliary pallets 10 or directly on the cassette conveyor 4. When auxiliary pallets 10 are used, these are always at the same distances from one another. - These distances are predetermined by the kiln furniture.

In comparison with the state of the art (especially European Patent Specification 0,162,153), the invention is characterized in that the freshly pressed severed extruded roof-tile mouldings 1 are now conveyed onto the cassette 2 directly, that is to say without a separate or additional gripping station interposed and without any mechanical action on the surface forming the visible side.

Claims

Claims:

1. Process for producing extruded roof tiles, in which the "green" extruded roof-tile mouldings cut off from the clay extrusion are brought to a distance from one another (spacing) and laid on cassettes (frames) and are guided on these cassettes through a drier and kiln, wherein (a) extruded roof-tile mouldings after being brought to a distance from one another (so called spacing), are laid directly onto a conveyor (moulding conveyor) conveying them away from the cutting station and carrying out the cassette loading, (b) the moulding conveyor engages under each moulding by at least two, preferably three conveyor bands running in parallel, (c) the moulding conveyor transports the extruded roof-tile mouldings on a path extending with low inclination at an acute angle of less than 300 relative to the path of movement of continuously transported cassettes and intersecting the path of movement of the cassettes, (d) the cassettes, in their supporting wall/supporting walling receiving/supporting the extruded roof-tile mouldings and extending at a distance from the cassettes standing plane, are equipped with conveyor band passages which allow a penetration of the moulding-carrying conveyor bands and a displacement of the cassettes under the conveyor bands, (e) the extruded roof-tile mouldings and the cassettes are transported equidirectionally (that is to say, in the same main direction) and synchronously in terms of speed, and (f) the movement of 1. a moulding cut-off device

2. the moulding conveyor and

3. the cassette conveyor is controlled synchronously as a function of the movement of the clay extrusion.

2. Process according to Claim 1, wherein two extruded roof-tile mouldings are laid successively behind one another at a distance on each cassette.

3. Process according to Claim 1 or 2 wherein the cassettes receiving the mouldings are transported/delivered, resting directly on a conveyor, on a horizontal path of movement and in close succession.

4. Process according to Claim 1 or 2, wherein the cassettes receiving the mouldings are transported/delivered on a horizontal path of movement and on distance-determining auxiliary pallets which rest on a conveyor.

5. Process according to Claim 1, wherein, after baking, the cassettes are emptied by means of conveyor bands which penetrate into the cassettes and allow them to pass and which grasp each extruded roof tile from below and convey it away on an oblique path.

6. Process according to any of Claims 1 to 5, wherein conveyor bands with a small deflection radius at the deflection point located on the same side as the cassettes, so-called "knife bands", are used for the loading and/or unloading of the cassettes.

7. Cassette frame for transporting roof tile mouldings including supporting wall (walling), socalled cassette web, located at a distance from the standing plane and intended for the laying-on of at least one extruded roof-tile moulding, preferably two mouldings to be arranged in series, and in which in the moulding-carrying cassette web there are at least two conveyor band passages (conveyor-band passage orifices) extending in the roof-tile moulding layingon direction and parallel to one another and for allowing a penetration of the conveyor band into the cassette and a displacement of the cassettes under the conveyor-band deflection located on the same side as the cassettes.

8. Cassette according to Claim 7, wherein the cassette web carrying the roof-tile moulding is formed by a grid extending between end standing elements, preferably standing walls, middle grid interstices forming the conveyor-band passages.

9. Cassette according to Claim 7 or 8, wherein, in that region between inner grid bars, U-like clearances are provided in the end standing walls to form the conveyor-band passages, so that continuous conveyor-band passages are present over the entire cassette length.

10. Cassette according to any of Claim 7 to 9, which is equipped, on the top side, with bosses for the laying-on of the mouldings at particular locations (points).

11. Apparatus for transporting roof tile mouldings including a frame as claimed in any of claims 7 to 10, means for conveying the frame and a moulding conveyor comprising at least two parallel conveyor bands arranged to pass into the frame as the frame is conveyed to the moulding conveyor whereby to convey a tile moulding onto or off of the frame.

12. A process for producing extruded roof tiles substantially as hereinbefore described with reference to the accompanying drawings.

13. A frame for receiving extruded roof tile mouldings substantially as hereinbefore described with reference to the accompanying drawings.

14. Apparatus for transporting roof tile mouldings substantially as hereinbefore described and with reference to the accompanying drawings.