FRASSON, Massimo (Via Don Milani 10, Monticello Conte Otto, I-36010, IT)
SARTOR, Mariano (Via Valcavasia 44, Cavaso Del Tomba, I-31034, IT)
ISOLI, Bruno (Via Buonarroti 7, Calvisano, I-25012, IT)
FRASSON, Massimo (Via Don Milani 10, Monticello Conte Otto, I-36010, IT)
SARTOR, Mariano (Via Valcavasia 44, Cavaso Del Tomba, I-31034, IT)
| CLAIMS 1) Machine (1) for inspecting a liquid substance (3) contained in a container (2), comprising: - an optical unit (4) that defines a viewing field; - grasping means (6) defining a reference axis (X) and configured so as to grasp said container (2) in such a way as to maintain the longitudinal axis of said container (2) coaxial with said reference axis (X); - means (5) for moving said grasping means (6); characterized in that said moving means (5) are configured so as to transmit to said reference axis (X) a predefined motion comprising a rotation according to a conical surface, so as to generate in said liquid substance (3) contained in said container (2) a swirling motion around said longitudinal axis. 2) Machine (1) according to claim 1), characterized in that said moving means (5) comprise an articulated arm (7) suited to define for said grasping means (6) at least two degrees of freedom corresponding to the rotation around two axes (Y1 , Y2) incident on each other, of which at least one first rotation axis (Y1) is incident on the direction of said reference axis (X). 3) Machine (1) according to claim 2), characterized in that also the second (Y2) of said rotation axes is arranged in such a way as to be incident on said reference axis (X). 4) Machine (1) according to any of the claims 2) or 3), characterized in that said articulated arm (7) defines at least one third degree of freedom for said grasping means (6). 5) Machine (1) according to claim 4), characterized in that said third degree of freedom corresponds to a rotation of said grasping means (6) around the third rotation axis (Y3) coaxial to said reference axis (X). 6) Machine (1) according to any of the claims from 2) to 5), characterized in that it comprises a logic control unit of said articulated arm (7) configured so as to generate simultaneous rotations of said grasping means (6) around said first and second rotation axes (Y1 , Y2) so as to obtain said predefined motion. 7) Machine (1) according to any of the claims from 2) to 6), characterized in that said articulated arm (7) is an anthropomorphic robot. 8) Machine (1) according to any of the preceding claims, characterized in that said grasping means (6) comprise pliers (10) suited to clamp containers of different sizes. 9) Machine (1) according to any of the preceding claims, characterized in that said grasping means (6) comprise one or more suction cups. 10) Machine (1) according to any of the preceding claims, characterized in that said optical unit (4) comprises a telecentric optical system. 11) Machine (1) according to any of the preceding claims, characterized in that said optical unit (4) comprises an optical system with variable focal length. 12) Method for inspecting a liquid substance (3) contained in a container (2) by means of a machine (1) comprising: - an optical unit (4) that defines a viewing field; - grasping means (6) defining a reference axis (X), configured so as to grasp said container (2) in such a way as to maintain the longitudinal axis of said container (2) coaxial with said reference axis (X); - means (5) for moving said grasping means (6), configured so as to transmit a predefined motion to said reference axis (X); said method comprising the following operations: - transmitting said predefined motion to said reference axis (X) via said moving means (5); - acquiring a sequence of images of said moving liquid substance (3) through said optical unit (4); characterized in that said predefined motion comprises a rotation of said reference axis (X) according to a conical surface, so as to generate in said liquid substance (3) contained in said container (2) a swirling motion around said longitudinal axis. 13) Method according to claim 12), characterized in that said predefined motion comprises also the overturning of said container (2). 14) Method according to any of the claims from 11) to 13), characterized in that said predefined motion comprises a rotation of said container (2) around an axis (Y3) that is coaxial with said reference axis (X). |
EMPLOYING SAID MACHINE.
DESCRIPTION
The present invention concerns a machine for inspecting the contents of containers with the aim to identify any defects and impurities.
The present invention also concerns an inspection method employing said machine.
The inspection of containers is an activity that is particularly widespread in the pharmaceutical industry, given the need to eliminate the product units presenting impurities that are potentially dangerous.
The above mentioned impurities are mainly constituted by foreign particles that have got into the container during packaging and may transport undesired microorganisms capable of contaminating the product.
In the particular case where it is necessary to inspect a liquid substance, particles are typically divided into three categories: floating particles, which remain on the surface of the liquid, suspended particles, which remain immersed in the liquid, and heavy particles, which are deposited on the bottom of the container.
According to a first known technique, inspection is carried out manually by an operator, who manually shakes the container in order to make the liquid move.
The operator then observes the container against a white and a black background, alternately, in such a way as to identify any moving particles inside it.
This technique is very flexible and, in principle, makes it possible to identify any type of particles, be they floating, suspended or heavy particles.
Furthermore, this technique also makes it possible to inspect substantially solid substances, like for example lyophilized pharmaceutical products, by observing the surface of the substance in order to identify any undesired inclusions.
However, this technique poses a first drawback, represented by the fact that it is scarcely repeatable, above all due to the subjective nature of inspection criteria, to the different degree of ability of operators and to the influence of environmental factors, in particular of lighting conditions.
A further drawback posed by the above mentioned manual technique is represented by its low productivity, which means a high cost per each unit inspected. Therefore, this technique poses the drawback of being anti-economical when the number of containers to be inspected is high, as it happens for example in the pharmaceutical industry, where production has increased exponentially over the last years.
The increasingly high volumes of product to be inspected and the need for reliable inspecting operations have led to the development of automatic machines for inspecting containers that work continually and ensure high inspection capacity together with a high degree of repeatability.
Typically, a known automatic inspecting machine comprises a system for transporting and handling a plurality of containers, as well as a given number of cameras or other analogous electro-optical systems for their inspection.
Inspection is carried out by imparting motion to the substance contained in the container and recording its movement by means of the cameras, which acquire a sequence of images that, properly processed with known algorithms, allow any defects or foreign particles to be identified.
In particular, for the inspection of liquid substances the container is first set rotating at high speed around its longitudinal axis in order to transmit a swirling motion to the liquid and involve in said motion also any particles contained therein, and successively it is abruptly stopped in front of the camera, in order to discriminate the particles moving in the liquid from simple defects of the container.
The rotation speed is typically in the order of a few thousand rev/min, so that friction between the walls of the container and the fluid is such as to impart considerable motion to the liquid in a very limited lapse of time.
The high speed is also necessary to raise any heavy particles that otherwise would remain invisible near the bottom of the container.
As regards the inspection of solid substances, this is carried out by slowly rotating the container in front of the camera, which can analyze the surface of the substance.
A first drawback posed by the inspection machines of known type described above is their high cost.
In fact, in order to set each container in motion independently of the others, the transport and handling system requires a large number of mechanical components.
Furthermore, in order to transmit the high rotation speeds required for the inspection of liquid products, it is necessary to use sophisticated devices, capable of rotating each container independently of the others and to stop it abruptly.
For the same reasons, a machine of the known type poses the further drawback of having considerable overall dimensions.
A further drawback is represented by the fact that the above mentioned machine allows only containers with specific shape and size to be inspected, so that in case of different shapes or sizes it is necessary to modify the equipment of the machine, bearing the consequent additional costs.
Said costs and dimensions also involve a further drawback, lying in that a machine of known type described above isn't suitable for inspecting containers produced in small series.
This is the case, for example, of some recently formulated products, which are expensive and require accurate inspection, so that an operator must carry out this process, with the inconveniences already described above.
Furthermore, in some cases the above mentioned products also present a high degree of dangerousness, so much so that manual inspection carried out by the operator becomes too risky.
Another important drawback of the machine described above is represented by the fact is that it doesn't allow all the foreign particles present in the container to be identified.
In fact, as the only motion imparted to the container is rotation around its longitudinal axis, it isn't possible to identify the particles lying on said axis, nor the floating particles that are confused with the surface of the liquid, nor those adhering to the upper part of the container that is not wetted by the moving liquid.
The present invention aims to overcome all the drawbacks described above, which are typical of the inspection techniques of known type.
In particular, it is a first object of the invention to provide a machine for inspecting containers and their contents that is less expensive than the machines of known type, though offering the same degree of inspection reliability.
It is also the object of the invention to provide a machine that is more flexible than the machines of known type, that is, that allows containers in different shapes to be inspected with no need to bear high equipment costs. The objects mentioned above are achieved by a machine for inspecting containers according to the main claim and by the variants described in the dependent claims.
In particular, the machine that is the subject of the invention transmits to the longitudinal axis of the container a rotary motion along a conical surface, said rotary motion being such as to generate a swirling motion around said longitudinal axis in the substance contained therein.
The motion described above advantageously makes it possible to transmit to the substance contained in the container a more complex motion compared to the motion generated by the machines of known type.
In particular, the motion just mentioned causes the container to move crosswise with respect to its longitudinal axis, so as to transmit to the substance contained therein a faster motion compared to the motion that can be obtained with the machines of known type, which make use of the friction generated by the high-speed rotation of the container around its own axis.
Therefore, to advantage, in order to obtain accurate inspection a low speed of the container is sufficient, which can be obtained with motors that in the whole are less expensive than those used in the machines of known type.
Advantageously, the lower cost of the machine of the invention makes it more convenient for inspection of containers produced in small series.
Still advantageously, the movement of the longitudinal axis of the container makes it possible to move also any particles that may lie on said axis, differently from what happens in the known technique described above.
According to a preferred embodiment of the invention, said movement is obtained by means of an articulated arm suited to rotate the container according to at least two mutually incident and independent axes.
To advantage, the articulated arm is more flexible and less complex than the moving systems of the known machines.
Furthermore, to advantage, the articulated arm is more versatile compared to the moving systems used in the machines of known type, as it can impart different motion sequences to the container, each one of which is more suited to a particular type of inspection.
Furthermore, the container can be overturned, thus allowing both the heavy and the floating particles to be easily identified.
Still advantageously, the machine that is the subject of the invention ensures a safe inspection of dangerous substances like, for example, some drugs used for treating some specific diseases.
Furthermore, the articulated arm makes it possible to reproduce a movement of the container that is similar to the movement imparted during a manual inspection.
This advantageously makes it possible to set the machine of the invention in such a way as to obtain inspection results that can be compared with those of a manual inspection.
The above objects and advantages are also achieved by an inspection method according to claim 12.
The said objects and advantages, and others which are better highlighted below, will be illustrated in detail in the description of a preferred embodiment of the invention which is provided by way of non-limiting example with reference to the attached drawings, wherein:
- Figure 1 shows an axonometric view of the machine that is the subject of the invention;
- Figure 2 shows the machine shown in Figure 1 in a different operating configuration;
- Figure 3 shows an enlarged detail of the machine shown in Figures 1 and 2;
- Figures 4a and 4b show a portion of the machine of Figure 1 , during application of the method of the invention;
- Figures 5a and 5b show a portion of the machine of Figure 1 , during application of a variant of the method of the invention.
The inspection machine that is the subject of the invention is shown in Figure
1 , where it is indicated as a whole by 1.
It is particularly suited to inspect liquid drugs contained in transparent containers like for example vials, bottles, syringes and the like.
The machine 1 is also suited to inspect the containers in order to identify any defects that may affect the soundness of the containers themselves.
As shown in the figure, the machine 1 comprises an optical unit 4 that defines a viewing field.
The optical unit 4 preferably comprises two cameras 4a, 4b with the respective focal axes orthogonal to each other that, allowing the simultaneous take of the container 2 from different angles, advantageously make inspection quicker.
According to construction variants of the invention, the cameras 4a, 4b can be positioned with their focal axes in a different arrangement from the one described above, provided that they can provide a stereoscopic image of the container 2 and its contents.
The above mentioned cameras 4a, 4b are preferably associated with a so-called "telecentric" optical system whose depth of field, as is known, is higher compared to traditional optical systems and that therefore advantageously make it possible to avoid image distortions.
According to construction variants of the invention, the cameras 4a, 4b use optical systems whose focal length varies, preferably automatically according to the dimensions of the container 2.
In further construction variants of the invention, the optical unit 4 may be provided with electro-optical systems different from cameras, using for example matrices of photodiodes or other equivalent devices, provided that they are capable of identifying any particles present in the substance to be analyzed and/or defects in the container.
As can be observed, always in Figure 1 , the machine 1 comprises also grasping means 6 that define a reference axis X and are configured so as to grasp said container 2 in such a way as to maintain its longitudinal axis coaxial with respect to the reference axis X.
The above mentioned grasping means 6 are associated with moving means 5 that make it possible to transport the container 2 from a collection point 8, where the container 2 is positioned while waiting for inspection, to the viewing field of the optical unit 4.
The machine 1 preferably but not necessarily includes a feeding unit 11 suited to move the containers to be inspected from a store 12 to the above mentioned collection point 8.
According to the invention, the moving means 5 are configured so as to transmit to the reference axis X of the grasping means 6 a rotary motion following a conical surface.
The above mentioned conical motion makes it possible to generate in the liquid substance 3 contained in the container 2 a swirling motion around the longitudinal axis of the container 2, as shown in Figure 4a.
Since said conical motion is obtained by displacing the longitudinal axis of the container 2, the liquid substance 3 contained therein is set in motion even if the movement of the container 2 is relatively slow, with no need to apply high rotation speeds as in the machines of known type.
Therefore, since it is not necessary to use the complex moving system typical of the inspection machines of known type, the invention achieves the object to provide a machine 1 that is less complex and less expensive than the machines of known type.
The moving means 5 preferably comprise an articulated arm 7, one end of which is associated with the grasping means 6.
The above mentioned articulated arm 7 is configured in such a way as to move the grasping means 6 and, consequently, the container 2, according to at least two degrees of freedom Y1, Y2 corresponding to the rotation around two axes incident on each other.
It is clear that at least a first one of said rotation axes, for example axis Y1 , is incident on the direction defined by the reference axis X, coinciding with the longitudinal axis of the container 2 when this is in grasping position.
Advantageously, the rotation around the first axis Y1 makes it possible to vary the inclination of the longitudinal axis of the container 2, in order to position it in front of the optical unit 4 with the orientation that is most suitable for the inspection to be carried out, as shown in Figure 5b.
This allows the machine 1 of the invention to be used also for the inspection of containers containing lyophilized drugs, or other solid or jelly substances, as the above mentioned rotation of the container 2 around the first axis Y1 makes it possible to take the side, upper and lower surfaces of the substance 3 with only two cameras 4a, 4b.
A further advantage of the articulated arm 7, which will be illustrated in greater detail below, lies in that it is able to develop different motions, whose limits are linked only to the number of the degrees of freedom and to the extent of movement of the articulated arm 7.
Consequently, the machine 1 of the invention makes it possible to carry out different inspections according to the substance 3 to be inspected, thus being more flexible than the machines of known type.
The articulated arm 7 preferably has additional degrees of freedom that allow it to collect the container 2 from the collection point 8, transport it within the viewing field and leave it in one or more delivery points 13a, 13b.
In this way, advantageously, the need to provide the complex moving systems that are necessary in the machines of known type can be eliminated, since an articulated arm 7 is sufficient to carry out all the operations required to move the container 2.
Additionally, the articulated arm 7 preferably makes it possible to arrange the container 2 in different points of the viewing field, in order to advantageously allow optimal focusing of the optical unit 4, independently of the shape and size of the container 2.
Preferably, also the second rotation axis Y2 of the articulated arm 7 is incident on the reference axis X, as is clearly shown in Figures 4a, 4b, 5a and 5b.
Therefore, by combining the rotations around said two incident axes Y1, Y2, it is possible to obtain the displacement of the longitudinal axis of the container
2, in such a way as to have it describe a curved surface, for example a portion of a conical surface.
In case of inspection of a liquid substance 3, the above mentioned trajectory, which is shown in Figure 4a, advantageously makes it possible to transmit a considerable swirling motion to the liquid, even following a slight movement of the container 2.
In fact, the above mentioned swirling motion cannot be obtained through simple friction between the container 2 and the liquid, as in the machines of known type, but owing to the thrust transmitted to the liquid by the displacement of the longitudinal axis of the container 2 along the above mentioned curved surface.
Furthermore, advantageously, the above mentioned swirling movement makes it possible to set in motion also any particles that may be aligned on the longitudinal axis of the container 2, since this motion is produced by a rotation around an axis that is different from the longitudinal axis.
Still advantageously, the combination of the rotations around said two axes Y1,
Y2 makes it also possible to overturn the container 2, as shown in Figure 4b, thus making the heavy particles fall and the light particles raise, the latter being thus easily identified.
Furthermore, the overturning of the container 2 causes the wetting of its upper dry portion, so that any particles adhering to it are captured.
It is clear that each one of the advantages described above means an inspection quality offered by the machine 1 of the invention that is much higher than that offered by the inspection machines of known type.
In particular, the combination of rotation and overturning of the container 2 makes it possible to identify all the types of particles present inside the container 2, thus obtaining a high-quality inspection process.
Actually, the above mentioned rotation and overturning movement is substantially analogous to the movement imparted by an operator to the container 2 during a manual inspection, which is undoubtedly among the most effective when identification of all the impurities present in the substance 3 is desired.
Advantageously, the above mentioned analogy with manual inspection facilitates also the setting of the machine 1, thus allowing the comparison of the results with those obtained by an operator.
The above mentioned overturning movement is preferably carried out in a sufficiently slow manner, so as to allow the gradual flow of the air bubble from one side of the container 2 to the other, and prevent the bubble from breaking up into a plurality of smaller bubbles, which would negatively affect the inspection process.
The articulated arm 7 preferably comprises a further degree of freedom corresponding to the rotation of the grasping means 6 around a third rotation axis Y3 that is coaxial with the reference axis X.
The above mentioned rotation can be advantageous in case of inspection of the already mentioned lyophilized substances, as it makes it possible to expose the entire lateral surface of the substance 3 to the cameras while maintaining the container 2 with its longitudinal axis fixed in front of the cameras and rotating it around the axis Y3, as shown in Figure 5a.
According to the above, the articulated arm 7 has in total at least three degrees of freedom corresponding to the three rotations around the axes Y1 , Y2 and
Y3, which allow inspection of containers containing both liquid and solid substances to be carried out in the ways described above.
It is evident, however, that according to different embodiments of the invention it is also possible to use only two of the above mentioned degrees of freedom, according to the type of inspection to be carried out.
In particular, it is possible to use an articulated arm 7 without rotation around the third axis Y3, which per se is not essential for the operation of the machine
1.
Obviously, it is possible to use an articulated arm 7 with any number of degrees of freedom exceeding two, preferably an anthropomorphic arm with six degrees of freedom that, advantageously, can arrange the container 2 in any point in space and with any orientation.
In particular, this flexibility of movement makes it possible to arrange the container 2 at different distances from the optical unit 4, so as to optimize focusing according to the size of the container 2.
The machine 1 of the invention also comprises a logic control unit for the articulated arm 7, not illustrated herein but known per se, suited to move the grasping means 6 in such a way as to obtain the predefined motion of the reference axis X, and therefore of the container 2.
In particular, the logic unit is configured so as to generate the above mentioned predefined motion via simultaneous rotations of the grasping means 6 around the first and the second rotation axes Y1, Y2.
The logic control unit is operationally connected to the optical unit 4, in such a way as to activate the cameras 4a, 4b when the container 2 is in taking position.
It is also preferable for the articulated arm 7 to be configured in such a way as to be able to arrange the containers 2 in at least two different delivery points
13a, 13b after inspection, depending on whether the outcome has been positive or negative, and as illustrated in Figure 2.
According to a construction variant, not illustrated herein, the articulated arm 7 arranges the containers 2 at the level of a single delivery point, while separation of the containers with positive outcome from those with negative outcome is obtained by means of a deviation device capable of conveying the containers towards two distinct collection areas.
Regarding the grasping means 6, illustrated in detail in Figure 3, they preferably comprise pliers 10 suited to clamp containers of different sizes.
The above mentioned pliers 10 preferably comprise a pair of shaped jaws 10a,
10b suited to be clamped on the opposite sides of the surface of the container 2.
The jaws are preferably closed at the level of an undercut area of the container
2 in proximity to its lid and on opposite sides with respect to the longitudinal axis of the container 2 itself.
Advantageously, this closing action on two opposite sides prevents the jaws from being interposed between the container 2 and the cameras, as is clear from Figure 4b. Furthermore, the jaws are preferably but not necessarily made of a transparent material, in order to avoid producing undesired shadows on the container.
It is evident, however, that in different embodiments of the invention the number, the material and the grasping method of the jaws can be different from those described above, provided that they are such as to allow a stable hold of the container in all the positions assumed by the latter during handling.
The jaws 10a, 10b are preferably V-shaped, as shown in Figure 3, said shape being advantageously suitable for grasping cylindrical containers having different diameters.
It is obvious, however, that the shape of the jaws can be different from the one described, provided that it is compatible with the type of container to be inspected.
The closing and opening of the jaws is preferably but not necessarily controlled by pneumatic actuators, not illustrated herein but known per se, suited to generate a pre-established force sufficient to firmly grasp the container 2 without breaking it.
According to a different embodiment of the invention not illustrated herein, the grasping means 6 comprise one or more suction cups, or means of another type suitable for guaranteeing a tight hold of the container 2.
An inspection machine in any of the embodiments described above makes it possible to implement the inspection method of the invention, comprising the following operations:
- transmitting a predefined motion to the reference axis X of the grasping means 6;
- acquiring a sequence of images of the moving liquid substance 3 by means of the optical unit 4.
According to the invention, the above mentioned predefined motion comprises a rotation of the reference axis X according to a conical surface, as shown in
Figure 4a.
Advantageously, the above mentioned rotation makes it possible to transmit a swirling motion to the liquid substance 3 contained in the container 2, said swirling motion making it possible to identify the particles present in the substance 3.
The above mentioned conical rotation is preferably obtained by combining the rotations around the two rotation axes Y1 and Y2 orthogonal to each other and to the reference axis X.
The above mentioned predefined motion preferably comprises also the overturning of the container 2, which can be obtained through a combination of the rotations around the two axes Y1 , Y2 and is illustrated in Figure 4b.
As previously described, the overturning makes it possible to move also the floating particles and the heavy particles present in the container 2.
The overturning preferably takes place in such a way as to arrange the container 2 with its longitudinal axis in vertical position.
However, in different embodiments of the method of the invention, the overturning movement can also be partial, provided that after the overturning movement the container 2 has the bottom facing upwards.
The two rotations around the axes Y1 and Y2 make it also possible to inspect solid substances, as they allow the container 2 to be arranged in front of the optical unit 4 with different angles, as shown in Figures 5a and 5b, so as to take the entire surface of the substance 3.
Still advantageously, the possibility to modify the inclination of the container 2 makes it possible to modify the incidence of the light source with respect to the object being taken, thus allowing the identification of some defects that may be invisible with the container 2 arranged in the other position.
Obviously, each rotation may have any angular extension, even if in most cases a rotation of 360° or less is sufficient.
Any of the embodiments of the invention described above can preferably include also a rotation of the container 2 around a third axis Y3 coaxial to the longitudinal axis of the container 2.
This rotation, shown in Figures 5a and 5b, is particularly advantageous when it comes to inspecting a solid substance 3, as it makes it possible to take the entire lateral surface of the substance 3 by rotating the container 2 around the third axis Y3 in front of a single camera.
Operationally, and as illustrated in Figure 1 , the containers to be inspected are arranged in a store 12, from which they are transported to the collection point 8 by means of the feeding unit 11.
The store 12 is preferably an inclined tank, so that the containers slide by gravity towards the feeding unit 11.
The feeding unit 11 comprises a conveyor belt 14 associated with a guide 16, whose geometry can be modified according to the type of container. The conveyor belt 14 conveys the containers at the level of an actuator 15, which pushes each container 2 to the collection point 8.
The actuator 15 is preferably configured so as to move containers of different shapes and sizes with no need to modify the configuration of the machine 1.
It is clear that the store 12 and the feeding unit 11 may have any construction form different from the one described above, provided that they allow the containers that are going to be inspected to be arranged on the collection point 8.
The invention preferably but not necessarily includes an auxiliary camera 9 suited to take the container 2 in the collection point 8, so as to identify any aesthetic defect of the same before inspecting the substance 3.
In this case power means may be provided that are not illustrated herein and are suited to rotate the container 2 with respect to the auxiliary camera 9, so that the latter can take the entire surface of the container 2 itself.
Once the container 2 has been arranged in the collection point 8, the articulated arm 7 grasps it with the corresponding grasping means 6 and transmits the predefined motion that is most suitable for the type of inspection to be carried out.
For example, in the case of liquid substances, the container 2 is moved so that its longitudinal axis describes a cone, as shown in Figure 4a.
Successively, the container 2 is overturned and arranged within the viewing field of the optical unit 4, as shown in Figure 4b, in a way sufficiently rapid to allow the still moving liquid to be taken.
In the case of solid substances, the container 2 is preferably brought within the viewing field and rotated by one revolution around its own longitudinal axis, so that a first camera 4a takes its bottom while a second camera 4b views the lateral surface of the substance 3.
The above mentioned rotation preferably takes place with the container 2 arranged with its longitudinal axis aligned with the focal axis of the camera 4a, as shown in Figure 5a.
Furthermore, the container 2 is also taken while arranged with its longitudinal axis inclined with respect to the focal axis of the cameras, if necessary by rotating the container 2 around the longitudinal axis, as shown in Figure 5b.
In this way, the camera 4a can take the lower angle of the container 2, where sometimes defects are present, while the camera 4b takes the upper surface of the substance 3.
In both cases, the images acquired by the cameras 4a, 4b are processed by means of an algorithm known per se, in order to identify any impurities present in the substance 3.
Successively, as shown in Figure 2, the articulated arm 7 transports the container 2 to one of the delivery points 13a, 13b, depending on the result of the inspection, pushing it so as to make the other containers, which have already been deposited, slide towards corresponding collection tanks.
The above clearly shows that the invention achieves all the set objects.
In particular, the invention achieves the object to provide a machine for inspecting a liquid substance contained in a container that is less expensive than the machines of known type and that therefore is suitable for inspecting containers produced in small series.
In fact, the conical motion of the container makes it possible to transmit a swirling motion to the liquid, with no need to rotate the container around its longitudinal axis at high rotation speeds.
This eliminates the use of the expensive devices for the fast rotation of the container that are used in the machines of known type.
Furthermore, the flexibility of use of the articulated arm makes it possible to handle a plurality of containers having different shapes and to carry out various types of inspection according to the substance to be analyzed, with no need to modify the equipment.
On implementation, the machine and the method that are the subjects of the invention may undergo changes that, though not illustrated in the drawings or described herein, shall nonetheless be covered by the present patent, provided that they come within the scope of the claims that follow.
In the cases where the technical characteristics illustrated in the claims are followed by references, these have been added only with the aim to facilitate the comprehension of the claims themselves and therefore said references do not have any limiting effect on the degree of protection to be granted to each element they identify only by way of example.