[0001] The invention relates to an improved automatic control machine intended to be used
in the ceramic industry.
[0002] The invention particularly relates to an automatic machine which was devised for
carrying out the so-called "selection" of flat ceramic articles, such as ceramic tiles
or slabs.
[0003] Even more in detail, the invention refers to a machine which is predisposed for performing,
on the tiles, at least a geometric control (or "linear measurement"), as well as a
flatness control.
[0004] There are known machines which are suitable to perform a sorting function based on
which ceramic tiles or slabs are sorted out or discarded.
[0005] In detail, the sorting machines may be located upstream of end stations, wherein
the tested articles are separated, thereby forming homogeneous groups or, as is usually
said, the tested articles may belong to the same "selection group".
[0006] There are further known automatic control machines which are able to perform both
a dimensional/geometrical control as well as an aesthetic control, in the sense of
providing to perform checkings on tone and defects of the articles.
[0007] The control machines comprise a cabin, wherein the optical control devices are located
and a conveyor which passes through the cabin and essentially consists of two parallel
belts driven by respective motors. The two belts support the articles and convey them
continuously within the cab, wherein they are tested and thereafter conveyed towards
the end of line, downstream of the machine.
[0008] The two belts are movable horizontally such that the reciprocal distance may be adjusted
based on the different sizes of the articles to be tested. Although the known machine
has proven to be able to function effectively, the same is not entirely free of drawbacks,
especially when used to perform control of very long and slim tiles, which are having
a great commercial deployment in the last time.
[0009] A first drawback relates to the flatness control of ceramic articles, in particular
tiles.
[0010] This control is aimed at checking flatness of the tested tile following laying thereof
on floors or coverings.
[0011] When freely resting on the conveyor belts, the tiles, especially slim and long sized
tiles as already mentioned, tend to bend due to gravity.
[0012] This circumstance constitutes a factor which distorts the flatness measurements performed
by conventional machines.
[0013] Furthermore, the known conveyor system requires the perfect parallelism of the two
belts, in that, even mild convergences or divergences have the effect of producing
a rotation of the tiles during transport, which affects the reliability of the measurements
performed by the machine.
[0014] The perfect parallelism of the belts is very complex to achieve, and above all, to
maintain.
[0015] Indeed, on the one hand, achievement of parallelism requires complex installation
and adjustment operations and, on the other, once obtained, the parallelism is rapidly
lost due to the stresses the belts are subjected to during use and, due to the repeated
movements away and towards, referred to above.
[0016] These drawbacks are exacerbated by the fact that the two belts may be activated independently
from one another, since each of them is driven by a respective motor.
[0017] Therefore, in the absence of a perfect synchronization of the two motors, which is
complicated to achieve and difficult to maintain, it takes place a rotation or a slipping
of the tile which is being conveyed on the belts, resulting in inaccuracies of the
measurements performed.
[0018] In this context, the technical task at the base of the present invention is to provide
a control machine which overcomes the drawbacks of the known art mentioned above.
[0019] The technical task mentioned is attained by the control machine realized in accordance
with claim 1.
[0020] Further characteristics and advantages of the present invention will become more
apparent from the indicative, and therefore non-limiting description of a preferred
but non-exclusive embodiment of the control machine illustrated in the appended figures
wherein:
- Figure 1 is a view in vertical section of the machine according to the proposed invention;
and
- Figure 2 is a schematic top view of the machine of Figure 1. With reference to the
appended figures, by 1 it is generically indicated a control machine for flat articles
2, such as ceramic tiles or slabs, which control machine constitutes the object of
the present invention.
[0021] As already mentioned above in the discussion on the prior art, the machine 1 herein
provided is intended to perform control operations automatically.
[0022] In detail, the machine 1 includes a control section 10 (shown in Figure 2) provided
with control means 11, 12 suitable for performing at least measurements of the geometric
type (or "linear measurement"), as well as flatness measurements on flat articles
2.
[0023] Preferably, the control means 11, 12 is of the type suitable to perform also aesthetic
checkings on the articles 2 tested.
[0024] For the sake of descriptive simplicity and without loss of generality, reference
will be made hereinafter to the exemplary case in which the flat articles tested are
tiles 2.
[0025] The machine 1 comprises conveyor means 3, 4, 5, 6 for continuously conveying the
tiles 2 to be tested towards the above-mentioned control section 10, and thereafter
toward the output of the machine 1.
[0026] According to an important aspect of the invention, the conveyor means comprises a
conveyor belt 3 suitable to support and move the tiles 2. In particular, the proposed
machine 1 comprises a belt 3 which defines a continuous conveyor belt, whereon the
tiles 2 to be tested are laid, one after the other.
[0027] The belt of the invention is thus capable of conveying the tiles in an advancement
direction D, parallel to the axis of the longitudinal development of the machine itself.
[0028] Even more in detail, the invention preferably comprises a single conveyor belt 3
which is able to convey alone the tiles 3.
[0029] Preferably, the width of the belt 3 defines the maximum transverse dimensions of
the conveyor means, possibly not including the input and output ends of the machine
1; this aspect shall be better detailed in a later section.
[0030] A cab 13 is mounted at the control section 10, in which cab 13 there is located the
control means 11, 12 mentioned above.
[0031] As shown schematically in Figure 1, the control means preferably includes optical
devices (such as cameras 11 and laser projectors 12), pointing in the direction of
the belt 3, i.e., towards the horizontal plane 31 on which the tiles 2 are passing
one after the other.
[0032] The control means may further include a processing unit for managing the optical
devices 11, 12 and processing the acquired images in order to perform control and
provide the results of performed calculations to the operator.
[0033] In this configuration, the belt 3 defines a kind of movable "floor" of the cabin
13.
[0034] As shown in the accompanying figures, the conveyor means comprises two opposite pulley
means 4, 5, respectively arranged at the input I and the output U of the machine 1.
[0035] Such pulley means may be constituted e.g. by rollers 4, 5 or similar rotatable elements.
[0036] The belt 3 of the invention, is closed in a loop around the two pulley means 4, 5
already mentioned, thereby defining two parallel and horizontal planes 31, 32.
[0037] The horizontal movable conveyor belt, whereon the tiles 3 are restingly lying, is
constituted by the upper surface 31 of the belt 3.
[0038] This upper surface 31 is crossing aforesaid control section 10, by entering and exiting
the cab 13 through appropriate openings.
[0039] In the preferred embodiment of the invention, the conveyor means comprises two guide
rollers 4, 5 in all, rotatable about the axes which are parallel to one another and
horizontal, which guide rollers 4, 5 are placed in opposite positions along the longitudinal
development of the machine 1. One of these rollers 4, for example the one arranged
at the output U, is set in rotation by a suitable motor 6, while the other roller
5 is preferably idler. Note that, as shown in Figure 1, the invention may provide
use of a backlight 14 arranged in the control section 10, below the upper surface
31 of the belt.
[0040] Preferably, the width of the belt 3 is equal to or greater than the maximum width
of the tiles 2 to be inspected.
[0041] In general, as mentioned above, the width of the conveyor belt 3 defines the maximum
transverse dimensions of the conveyor means, at least in the portion comprised between
the two pulley means 4, 5.
[0042] An alternative embodiment is however not to be excluded, wherein, albeit the belt
3 has a width less than that of the tiles 2 to be tested, this width is sufficient
to allow conveyance of the tiles 2.
[0043] The advantages of the proposed invention are listed below.
[0044] The conveyor belt 3 of the machine 1, which extends to the whole width with respect
to the conveying zone, supports the tiles 2 by coming in contact with the entire bottom
surface, or in any case a preponderant portion thereof.
[0045] Thus, the tile 3 is resting on a continuous horizontal plane 31, which completely
prevents or greatly limits the effects of gravity on the flatness of the tiles 2 conveyed,
i.e., that kind of bending effect which, tends to distort flatness measurements in
the prior art.
[0046] Hence, the invention is able to perform reliable flatness measurements even in relation
to long and slim tiles referred to above.
[0047] Additionally, the fact of providing a single conveyor belt 3 instead of the two belts
of the prior art, allows to overcome all of the drawbacks due to use of a plurality
of independent conveyor elements.
[0048] In particular, owing to the control machine 1 of the invention, the tiles 2 may translate
without being subjected to any rotations which in the prior art are due to imperfect
parallelism of the belts.
[0049] Similarly, given that the operation of the machine herein disclosed is based on a
single motor 6 which drives the conveyor belt 3, the machine is not subject to any
synchronization problems which instead affect the two motors associated with the two
belts of the known machines.
[0050] Additionally, the fact that a single conveyor belt 3 was provided, makes it possible
to avoid the complication of having to move forward or away the belts according to
the different sizes of the tiles 2 to be tested.
[0051] Finally, the machine 1 of the invention of course includes a support base 7 consisting
of a pallet or the like and may include additional devices and components the control
machines are usually provided with.
1. A control machine (1) for flat articles (2), such as ceramic tiles or slabs, comprising:
a control section (10), provided with means (11, 12) for the geometric and flatness
control of flat articles (2); and
conveyor means (3, 4, 5, 6) for conveying the articles (2) in said section (10);
characterized in that said conveyor means comprises a conveyor belt (3), suitable to convey and move flat
articles (2).
2. A machine (1) according to the preceding claim, comprising a single conveyor belt
(3) which is suitable to convey alone flat articles (2).
3. A machine (1) according to at least any preceding claim, in which the belt (3) has
a width that defines the transverse dimensions of the conveyor means.
4. A machine (1) according to at least any preceding claim, wherein said conveyor means
comprises two pulley means (4,5) respectively arranged at the input (I) and output
(U) of the machine (1), around which pulley means (4,5) said conveyor belt (3) is
closed in a loop.
5. A machine (1) according to at least any preceding claim, in which the belt (3) defines
a horizontal movable belt (31) between said pulley means (4, 5).
6. A machine (1) according to claim 4 or claim 5, wherein said conveyor means comprises
a motor (6) capable of rotating one of said pulley means (4, 5).
7. A machine (1) according to at least any preceding claim, comprising a cabin (13) arranged
at the control section (10), which is crossed by the belt (3), in which said control
means comprises optical control devices (11, 12) pointing in the direction of the
belt (3).