EP2322320A1

EP2322320A1 - Calibrating-polishing system for surfaces of stone material with reduced emission of noises

Info

Publication number: EP2322320A1
Application number: EP09425466A
Authority: EP
Inventors: Luca Bonato
Original assignee: MBD SRL
Current assignee: MBD SRL
Priority date: 2009-11-17
Filing date: 2009-11-17
Publication date: 2011-05-18

Abstract

A calibrating-polishing system (1) is described, for slabs (3) made of stone material, in particular slabs made of natural stone, of the type comprising a series of tool-holder heads (P1, P2) arranged so that the slab (3) is subjected to a mechanical action due to tools with progressively decreasing dimensional grain, starting the contact with tools having super-coarse grain, and being subjected in a sequence to the action of tools with all intermediate grains, ending the contact with the tools having super-fine grain; the system is adapted to perform a calibration of the slab (3) by means of a combination of a linear advancing motion of the slab (3) with a continuous transverse motion of a tool so that the contact between the slab (3) e the tool occurs simultaneously in many points arranged along the whole side which is transverse to the advancement direction of the slab (3).

Description

The present invention deals with a calibrating-polishing system for the surfaces of stone materials, ceramics, marble, granite.
The working process of slabs made of stone material occurs due to the effect of the mechanical-chemical action of the tool in contact with the slab when there is cooling and lubrifying fluid. The mechanical action employs the combination of abrasion, bumps and cutting of a tool composed of a multitude of grains of hard material embedded into a soft matrix with progressibely decreasing sizes.
A combined system for calibrating and smoothing-polishing slabs made of stone material, herein below called calibrating-polishing system, comprises a series of tool-holder heads arranged so that the slab is subjected to a mechanical action due to tools with progressively decreasing dimensional grains, starting the contact with tools having super-coarse grain, being subjected in a sequence to the action of tools of all intermediate grains, and ending the contact with tools having super-fine grain.
The tool-holder heads impart to the tools a cutting speed compatible with the characteristics of the tool material and the nature of the stone to be worked.
The tool approach with respect to the slab surface occurs in an orthogonal direction to the surface of the slab, by pressing onto the slab with a variable pressure depending on the nature of the stone to be worked.
The slab advances with linear motion.
For calibrating-polising slabs having big sizes, the calibrating-polishing system provides for the combination of a transverse movement of the tool-holder heads with the linear advancement movement of the slab, in order to allow covering the whole surface of the slan in transit.
A calibrating-polishing system emits noises above certain values of admissible threshold. In order to reduce or remove this problem, noise reducing and system insulating arrangements are adopted, together with insulating the portion of system in which the occurrence of acoustic effects outside standards is greater.
The slab interaction with tols with coarse grains in fact creates high noises. Therefore, it is nowadays customary to coar the portion of system in which slab calibration occurs with a sound-dampening cabin.
The noise emission due to the interaction of the tool with coarse grains with the slab to be calibrated is a double problem regarding environmental hygiene and system operating reliability.
Environmental hygiene is observed by adopting a sound-proofing through a covering cabin of the area in which the calibrating tool-holder heads are placed.
The system operating reliability is obtained by raising the quality and resistance standards of electronic control systems and structural components composing the machine.
Another approach to keep the system reliability level high is dynamically separating the portion of the calibrating system with respect to the portion of the polishing system, by using different working planes, with related conveyor belt, and different supporting structures of the tool-holder heads.
In this way, the dynamic coupling is avoided of low-frequency vibrations induced by coarse-grain calibrating tools with vibrations of tools used for finishing the slab at the end of the polishing process.
Object of the present invention is reducing the emissions of noises in a calibrating-polishing system without having to use sound-proofing apparata or having to uncouple the carrier structure.
This object is reached by a system, as claimed in claim 1, in which calibration of a slab is obtained due to the effect of the combination of the linear advancement motion of the slab with the continuous transverse motion of the tool, so that the contact between slab and tool occurs simultaneously in many points arranged along the whole transverse side of advancement of the slab.
The present invention will be better described by a preferred, but not limiting, embodiment thereof, with reference to the following figures:

figure 1 and figure 2: axonometric and sectional views in a plane orthogonal to the advancement direction of the slab in the calibrating-polishing system of the present invention;
figure 3: axonometric view of the interaction of the slab with the calibrating tools according to the present invention.

A calibrating-polishing system 1 comprises a working plane 2 in which a carpet 4 slides, which allows the slabs made of stone material 3 to transit along direction AD.
A framework 5, composed of risers 6.1, 6.2, 6.3, 6.4 and fixed beams 7.1, 7.2, supports the calibrating heads 21.
The portion of the calibrating system comprises at least one station C1. The optimum configuration provides for two calibrating stations C1 and C2 arranged in a sequence.
A framework 8, composed of risers 9.1, 9.2, supports beams 10.1 and 10.2 transversely oscillating with respect to direction AD, along which the polishing heads 31 are arranged.
The portion of the polishing system comprises at least one array of tool-holder heads P1. The optimum configuration provides for two arrays of tool-holder heads P1 and P2.
Safety panels 11 cooperate with the calibrating portion C1 and C2, in order to comply with the safety requirements of operators of systems in the stone-working sector according to the laws in force.
Each calibrating station C1, C2 comprises a head 22 with big sizes, which supports a series of tool-holder spindles 23 radially arranged with respect to the rotation centre R and with the same angular pitch. The tools have a cylindrical shape. The head 22 continuously rotates with respect to the fixed axis of a shaft 24 perpendicular to the surface of the slab 3 and connected to the fixed beam 7.1, 7.2 of the carrier structure of the portion of the calibrating system C1, C2; the tool-holder spindles 23 rotate at a speed corresponding to the peripheral cutting speed Vp compatible with the characteristics of the material of the slab 3 to be calibrated.
Each polishing station P1, P2 comprises an array of heads 31 characterised by a vertical approach assisted by hydraulic pressure transmitted by a compressed-air system. Each head comprises a series of spatula-type tools having a tangential oscillating movement with respect to the plane of the slab 3. Heads equipped with cylindrical tools having a continuous tangential movement can be a variation in the configuration of the portion of the polishing system P1, P2.
The portion of the calibrating system made with a central head 22 connected to a series of tool-holder spindles 23 radially arranged with respect to the rotation centre 24 allows satisfying the objective of balancing the cutting forces through a distribution of the slab-tool contact along the whole transverse side of the slab 3 with respect to the advancement direction AD.
The use of a calibrating system with contact distributed on the transverse side of the slab 3 perpendicular to direction AD, coupled with a polishing performed conventionally with arrays of heads 31, allows reducing the noises emitted by the machine.
The advantages that are obtained with respect to the conventional approach are:

removal of the sound-proofing cabin;
simplified carrier structure, in particular free from dynamic uncoupling between the calibrating and polishing portions of the system.

The configuration with two calibrating stations C1, C2 composed of heads 21, each one equipped with twenty-four spindles 23, ensures an optimum distribution of the cutting forces transmitted by the tools to the slab 3 along the whole transverse side of the slab 3.

Claims

Calibrating-polishing system (1) for slabs (3) made of stone material, in particular slabs made of natural stone, of the type comprising a series of tool-holder heads (P1, P2) arranged so that the slab (3) is subjected to a mechanical action due to tools with progressively decreasing dimensional grain, starting the contact with tools having super-coarse grain, and being subjected in a sequence to the action of tools with all intermediate grains, ending the contact with the tools having super-fine grain, characterised in that the system is adapted to perform a calibration of the slab (3) by means of a combination of a linear advancing motion of the slab (3) with a continuous transverse motion of a tool so that the contact between the slab (3) e the tool occurs simultaneously in many points arranged along the whole side which is transverse to the advancement direction of the slab (3).
Calibrating-polishing system (1) according to claim 1, characterised in that the portion of the calibrating system comprises at least one station (C1) in which a central head (22) having big sizes supports a series of tool-holder spindles (23) radially arranged with respect to the rotation centre (R) and with the same angular pitch.
Calibrating-polishing system (1) according to claim 1, characterised in that the portion of the polishing system comprises at least one array (P1) of tool-holder heads (31) which perform a vertical approach assisted by hydraulic pressure transmitted by a compressed-air system.
Calibrating-polishing system (1) according to claim 3, characterised in that each head (31) comprises a series of spatula-type tools having a tangential oscillating movement with respect to the plane of the slab (3).
Calibrating-polishing system (1) according to claim 3, characterised in that each head (31) comprises a series of cylindrical tools having a continuous tangential movement.