Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B11/00—Apparatus or processes for treating or working the shaped or preshaped articles
  • B28B11/12—Apparatus or processes for treating or working the shaped or preshaped articles for removing parts of the articles by cutting
  • B28B11/125—Cutting-off protruding ridges, also profiled cutting

Definitions

• the present invention relates to a mechanical device for rounding off the longitudinal edges of heavy clay products during the production phase particularly, but not exclusively, for extruded bent tiles and that differs from the known device reported on the document GB 03456 A A.D. 1912 (HEATON JAMES) 3 October 1912, page 5 lines 1-5 and figure 7, lines 6-8 e figure 6.
• Table 1 shows figures 1 , 2, 3, 4 and 5.
• Figure 1 is a perspective view of a bent tile while figure 2 is a front view of the same element. Both are used here to explain the problem that is to be solved by the present invention.
• Figure 3 is a partial perspective view of a bent tile that has been chamfered along its longitudinal edges while figure 4 is a front view of the same element.
• Figure 5 is a front view of a bent tile that has been chamfered along its longitudinal edges in a slightly different way.
• Figures 3, 4 and 5 are used here to describe the state of the art of the existing solutions.
• Table 2 includes figures 6 and 7.
• Figure 6 illustrates a front view and a perspective view of the invented device as it may appear when fitted on a cutting machine.
• Figure 7 illustrates two more perspective views of the invented device.
• FIGS 6 and 7 are used here to describe the device itself and its working principle.
• Table 3 includes figure 8, which illustrates 4 orthogonal views and 3 perspective views of the cutting tool of the invented device.
• the production process of extruded clay elements for roofing which are commonly called bent tiles, includes the phases of extrusion, cutting of the pasty clay, drying, firing and then packaging of the final product.
• the raw clay is prepared and mixed with water to form a pasty material, with the desired moisture level, that is forced through a die by an extruder.
• a clay slug coming out the die and being carried forward by a conveyor belt, is produced.
• a production process with 1 , 2, 3, 4 or more exits can be set up, where each exit provides a cross section of tile to be cut.
• the shaped slug is carried forward to the cutting machine where the tiles elements, of the desired dimension and shape, are generated by means of flying cut operations. After exiting the cutting machine, tiles are picked up by handling devices and transferred to the drying section, while the waste part of the slug is conveyed back to the extruder and recycled
• the first solution is found in machines that use wires for cutting the bottom surfaces of the tiles and consists of two steel knives that, working nearby the cutting wire, chamfer the outer edges. In this case each sharp edge is replaced by a chamfer, (4) and (5), that is almost perpendicular to the bottom surfaces.
• the second solution is to cut out the bottom surfaces by the use of a pair of symmetric steel tools instead of a wire.
• Each tool consists of a piece of extruded, circular or rectangular, thick wire that has been curved in a hook-shaped way.
• the use of such tools allows the obtaining of bottom surfaces that are round-shaped along the whole width or just along the external part, according to the geometry of the tools. An example is given in figure 5. In this case risks of chipping are reduced because the outer edges are no longer acute and also out above the resting plane.
• the innovative device here described (6) has been designed to be fitted on the travelling unit (7) of machines that cuts the bottom surfaces of the bent tile by means of wires.
• the device includes, for each exit of the extrusion process, a pair of moving tools whose geometrical shape has been purpose designed (8).
• the tools are symmetrical to each other with respect to the symmetry plane of the tile.
• Each tool is fixed at its toll-holder bar (9) that is, in turn, fitted on to a linear slider (10). Given that, each tool has just one degree of freedom that is translation along horizontal axis and thus perpendicular to the feed direction of the slug and parallel to the cutting wire.
• the tool is driven by a linear actuator (11) acting in force-controlled mode.
• the actuator can either be a fluid-powered cylinder, liquid or gas, or an electro-mechanic or electronic device.
• the innovation of the present device consists in its working principle, made possible by both the purpose-designed geometry, see figure 8, and the driving mode of the tool.
• the device In its working configuration the device is fitted on the cutting machine and tuned up in such a way that:
• the tools can move parallel to the cutting wire
• the working surfaces (13) and the cutting edges of the tool (14) are placed upstream the wire with regard to the slug feeding direction.
• actuators keep tools opened, that is they stay off the slug and do not interact with it.
• actuators are powered to drive tools towards the slug.
• Each tool penetrates the slug, which has a defined range of plasticity, until it stops when its wide purpose- made contact surface (15) leans against the outer surface of the slug.
• the wide contact surface and the controlled force applied by the actuator each tool is pushed against the outer surface of the slug with the desired pressure.
• each tool slides along the outer surface of the slug while remaining upstream the wire.
• the cutting edge of the tool (14) engraves the slug right where the wire is to cut the bottom surface of the tile. In this way the desired rounded border is created.
• actuators are powered to reverse and tools are driven off the slug.
• the cutting wire is always downstream and, in particular, bound behind the profiling tool in correspondence of the outer edge of the tile, the clay being cut off by the tool from the upper part of the slug always remains stuck to the lower portion of the slug, which is the waste.
• the device is self adjusting, that is it is intrinsically able to drive tools to follow the surface that has to be worked, regardless of the wear of tools and/or small transversal shifts of the slug. Therefore the device allows to obtain consistent profiling operations all along the tile length and among all the produced tiles;

Landscapes

• Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Mechanical Engineering (AREA)
• Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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Cited By (1)

Citations (1)

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• 2009
  • 2009-05-14 IT ITTV2009A000096A patent/IT1394146B1/it active
• 2010
  • 2010-05-10 WO PCT/EP2010/002854 patent/WO2010130390A2/en active Application Filing
  • 2010-05-10 PT PT107471559T patent/PT2429789E/pt unknown
  • 2010-05-10 SI SI201030530T patent/SI2429789T1/sl unknown
  • 2010-05-10 ES ES10747155.9T patent/ES2450139T3/es active Active
  • 2010-05-10 EP EP10747155.9A patent/EP2429789B1/en active Active

Patent Citations (1)

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