Apparatus and method for analyzing plastic caps

Abstract

An apparatus (1) for analyzing a plastic cap (T), wherein the cap extends around its respective longitudinal axis (L), the cap has marks and cuts, the cuts are on the side (SL) of the cap, the apparatus comprises a conveyor (2), an upper camera (3), an upper illuminator (4), a plurality of side cameras (5), a side illuminator (6), and a control unit configured to sequentially and selectively operate the upper and side illuminators so that at a first time the side illuminators are turned on and the upper illuminators are turned off, and at a second time the upper illuminators are turned on and the side illuminators are turned off, the control unit is configured to command the side cameras to take a first image at the first time, command the upper cameras to take a second image at the second time, processes the first and second images, and verifies the relative angular position between the cuts and the corresponding marks, wherein the first time point precedes the second time point, or the second time point precedes the first time point.

Description

Technical Field

[0001] The present invention relates to an apparatus and a method for analyzing a plastic cap, wherein the cap extends around its respective longitudinal axis, and the cap is provided with a cut formed on a side surface of the cap and a mark.

Background Art

[0002] The present invention relates to the technical field of an optical inspection system applied to a bottling machine, and particularly relates to the inspection of caps, especially the inspection of the relative angular position between the cut of the cap and the corresponding respective mark.

[0003] Typically, the cap includes a body and an anti-tampering ring, and the body is connected to the anti-tampering ring by a connecting tear strip. More specifically, when the user first twists and opens the cap, the body is separated from the anti-tampering ring, and the anti-tampering ring remains attached to the neck of the container. In other types of caps, such as caps known as "tethered caps", the permanent connection zone of the tear strip does not tear, and the cap body remains attached to the anti-tampering ring. Therefore, tethered caps help prevent loss and reduce litter scattering.

[0004] In both traditional caps and tethered caps, the connecting strip may include a series of cuts or slits and a bridge, i.e., a tearable connection zone between the body and the anti-tampering ring. Alternatively, especially in the case of tethered caps, the connecting strip includes a depression, i.e., a narrow thick portion thinner than the body and the anti-tampering ring, which is torn when the cap is first twisted and opened.

[0005] These cuts or narrow zones may be formed during the steps of forming the cap (by compression, injection, or both compression and injection), for example, by using the mold itself or a movable drawer of the mold, or during post-forming steps, for example, by slitting the cap using a specific knife, or by a material removal process.

[0006] In this regard, patent WO2022175824 provides a cutting machine.

[0007] In this field, it is therefore important to inspect the cuts to ensure that they are properly formed. Inspection systems known in this field are used to detect defects in caps, and involve observing the cap from the outside to inspect the outer wall of the cap, or observing the cap from above. Patent document 102020000012214 in the name of the present applicant provides an apparatus and method for inspecting caps.

[0008] Typically in this field, caps are marked with indicators or marks to ensure that the cuts are formed accurately. These marks are usually located on the bottom or inside of the cap. Cuts can be formed in various shapes, for example, horizontally or vertically. The marks are used as a reference to identify the absolute position for positioning the blade that forms the cut. For a correct cut to be obtained, the marks must be aligned with the blade that forms the cut.

[0009] In this field, inspections must be performed downstream of the cutting machine to check that the cutting machine forms cuts or indentations in the correct positions (i.e., that the cuts align with the marks) in order to enable proper opening.

[0010] Patent document JPH09169392A discloses an inspection device for a beverage manufacturing process in which a beverage is filled into a translucent container using a beverage filling machine, and then a cap is attached to the mouth of the container using a capping machine to keep the inside of the container airtight, wherein the inspection device simultaneously performs a capping condition inspection after the capping process, such as checking for missing caps or the depth or tilt of the caps; a capping inspection, such as checking the cap label to determine the type of cap; and a label inspection, such as determining the type of label attached to the container body and checking for misalignment of the attached label. The device described herein includes a laser light source positioned in a vertical cross section substantially passing through the central axis of the beverage filling container so as to be able to irradiate red laser light from the lower end of the cap to the back of the upper part of the cap in order to illuminate the cap body from the inside; a color imaging device for the laser light positioned substantially opposite the laser light source and toward the cap body; a light source that irradiates light of a color other than red toward the cap body; and a color imaging device for the light source positioned opposite the light source with the cap in between. However, the solution in JPH09169392A can only check whether the capping process was performed correctly, and does not provide a solution for verifying the correct position of the cuts. [Overview of the Initiative]

[0011] This disclosure aims to overcome the shortcomings of the prior art described above by providing an apparatus and method for analyzing plastic caps, each of which has cuts and marks formed on its side surface.

[0012] In particular, the object of this disclosure is to provide an apparatus and method for analyzing plastic caps, each of which has cuts and marks formed on its side, which is particularly efficient and accurate in enabling the analysis of caps with various types of cuts.

[0013] This objective is fully achieved by the apparatus and method of the present disclosure, as characterized in the appended claims.

[0014] This disclosure, according to one aspect thereof, provides an apparatus for analyzing a plastic cap having marks and cuts. The cuts are formed on the side of the cap. The cap extends around its respective longitudinal axis. The apparatus comprises a conveyor. The conveyor is configured to transport the cap along a path. The conveyor transports the cap to a first inspection position. At the inspection position, the longitudinal axis of the cap is aligned with the first inspection axis. The conveyor also transports the cap to a second inspection position. At the second inspection position, the longitudinal axis of the cap is aligned with the second inspection axis.

[0015] The apparatus (or simply the apparatus) for analyzing a plastic cap includes a top camera. The top camera is configured to observe the cap from above at a first inspection position. In particular, the top camera observes the cap from above at the first inspection position along an optical path directed along the first inspection axis. The apparatus includes a top illuminator. The top illuminator is configured to illuminate the cap from above at the first inspection position. The illuminator illuminates the cap from above with a ray directed along the first inspection axis. The apparatus also includes a plurality of side cameras. The plurality of side cameras are positioned laterally with respect to a second inspection axis. The side cameras are positioned angularly apart from each other with respect to the second inspection axis. The side cameras are directed laterally with respect to the second inspection axis toward the second inspection axis. The side cameras are used to observe the cap from the side at the second inspection position.

[0016] The apparatus also includes a side illuminator. The side illuminator is configured to illuminate the side of the cap positioned at the second inspection location.

[0017] The device also includes a control unit. The control unit is configured to sequentially and selectively operate the upper and side illuminators. In particular, the control unit is configured to sequentially and selectively operate the upper and side illuminators such that at a first time point the side illuminators are on and the upper illuminators are off, and at a second time point the upper illuminators are on and the side illuminators are off. The control unit is configured to instruct the side camera to take a first image at a first time point. The control unit is configured to instruct the upper camera to take a second image at a second time point. In one example, the first time point precedes the second time point. In another example, the second time point precedes the first time point.

[0018] The control unit is configured to process the first and second images to verify the relative angular position between the gap and the corresponding marks.

[0019] Therefore, according to one aspect of this disclosure, the illuminator and camera are operated sequentially at two different points in time. This solution makes it possible to analyze the caps continuously and without stopping the conveyor, thus making it possible to obtain a particularly efficient device. Furthermore, the side camera and top camera make it possible to provide images of the caps from different angles. By integrating and analyzing these images, all kinds of cracks can be inspected. Thus, it is possible to obtain a particularly efficient device.

[0020] In one example, the control unit is programmed to set a predetermined time interval between a first time point and a second time point. This solution makes it possible to illuminate the cap and accurately capture an image.

[0021] In one example, the conveyor is configured to transport the caps individually along a path. Along the path, the caps are also placed a predetermined distance apart from each other.

[0022] In one example, the device includes a position sensor. The position sensor is configured to detect a position signal representing the position of the cap at a predetermined position upstream of the first and second inspection positions. The control unit also receives the position signal. The control unit is configured to instruct the upper camera and the side camera to take the first and second images based on the position signal.

[0023] In this way, the control unit can calculate the first and second time points based on the position of the detected cap on the conveyor, and thus can operate the illuminator and the camera more accurately.

[0024] In one example, the conveyor includes a plurality of holes along it. Each hole is provided with a suction means. The holes are arranged apart from each other such that at least two holes act on the same cap simultaneously.

[0025] With this solution, it is possible to hold the caps at the same angular position along the conveyor.

[0026] In one example, the upper illuminator and the side illuminator include strobe lights. With this solution, it is possible to operate the side illuminator and the upper illuminator at the first and second time points respectively in sequence without stopping the cap.

[0027] In one example, the upper camera, the upper illuminator, the plurality of side cameras and the side illuminator are arranged at an inspection station. At the inspection station, the cap can be arranged at the first and second inspection positions. In this example, the upper illuminator and the side illuminator are configured to illuminate an inspection volume surrounding the cap at the inspection station.

[0028] In this example, the illuminator configured to illuminate the volume of the inspection station at one of the first and second time points and preceding the other of the first and second time points includes a strobe light.

[0029] Alternatively, the side illuminator and the side camera may be arranged at the first inspection station. At the first inspection station, the cap is at the first inspection position. Further, the top illuminator and the top camera may be arranged at the second inspection station. The second inspection station is arranged along the conveyor away from the first inspection station. At the second inspection station, the cap may be placed at the second inspection position. In this example, the side illuminator is configured to illuminate the first inspection volume, and the top illuminator is configured to illuminate a second inspection volume different from the first inspection volume.

[0030] It should be noted that in one example, the first inspection position may coincide with the second inspection position. In this example, the cap is stopped when it reaches the inspection position to take side observation images and top observation images. Also in this example, the illuminators are operated in sequence as described above.

[0031] According to another aspect of the present disclosure, a method for analyzing plastic caps is provided. The caps extend about their respective longitudinal axes. The caps are provided with marks. The caps are also provided with cuts formed on the sides of each cap. The method includes the step of conveying the caps along a path. The caps are conveyed to the first inspection position. At the first inspection position, the longitudinal axis of the cap is aligned with the first inspection axis. The caps are also conveyed to the second inspection position. At the second inspection position, the longitudinal axis of the cap is aligned with the second inspection axis.

[0032] The method includes the step of observing the cap located at the first inspection position from above through the top camera. The top camera observes the cap along an optical axis directed along the first inspection axis.

[0033] The method includes the step of illuminating the cap located at the first inspection position from above. The step of illuminating the cap from above is performed by the top illuminator. The cap is illuminated from above with light rays directed along the first inspection axis.

[0034] This method includes the step of observing a cap located at a second inspection position from the side. The cap is observed from the side by multiple side cameras. The multiple side cameras are positioned laterally with respect to the second inspection axis. The multiple side cameras are positioned at an angle to each other with respect to the second inspection axis and are oriented laterally with respect to the second inspection axis.

[0035] This method includes the step of illuminating the side of the cap using a side illuminator.

[0036] This method includes the step of sequentially and selectively operating the upper illuminator and the side illuminator such that at a first time, the side illuminator is turned on and the upper illuminator is turned off, and at a second time, the upper illuminator is turned on and the side illuminator is turned off.

[0037] The method includes the step of instructing a side camera to take a first image at a first time point. The method includes the step of instructing a top camera to take a second image at a second time point. The first time point precedes the second time point, or the second time point precedes the first time point. The method includes the step of processing the first and second images to verify the relative angular position of the gap with the corresponding marks.

[0038] This method may include the step of setting a predetermined time interval between a first time point and a second time point.

[0039] This method includes the step of transporting the caps individually along a route. Along the route, the caps are arranged to be spaced apart from each other by a predetermined distance.

[0040] This method may include the step of detecting a position signal. The position signal represents the position of the cap at a predetermined position located upstream of the first and second inspection positions.

[0041] This method includes the step of instructing the upper camera and the side camera to take first and second images based on position signals.

[0042] In one example, a top camera, top illuminator, multiple side cameras, and side illuminators are positioned at the inspection station. At the inspection station, the cap is in first and second inspection positions. In one example, the top and side illuminators illuminate the inspection volume surrounding the cap at the inspection station.

[0043] In one example, the illuminator that illuminates the inspection volume of the inspection station at one of the first and second time points, which precedes the other of the first and second time points, includes a strobe light.

[0044] In one example, a side illuminator and a side camera may be located at a first inspection station. At the first inspection station, the cap is in a first inspection position. Furthermore, an upper illuminator and an upper camera are located at a second inspection station. The second inspection station is located away from the first inspection station along the conveyor belt. At the second inspection station, the cap is in a second inspection position, with the side illuminator illuminating the first inspection volume and the upper illuminator illuminating a second inspection volume, which is different from the first inspection volume.

[0045] In one example, a strobe light is used to illuminate the cap from above and then to illuminate the sides of the cap. [Brief explanation of the drawing]

[0046] These and other features will become clearer from the following description of preferred embodiments shown in the attached drawings as non-limiting examples. [Figure 1] An apparatus for analyzing plastic caps, according to one or more embodiments of the present disclosure, is shown. [Figure 2] A cross-sectional view of the device is shown. [Figure 3] An exemplary embodiment is shown in which the apparatus includes two inspection stations. [Figure 4] The side and top cameras of the device are shown. [Figure 5]A cap according to one or more aspects of this disclosure is shown. [Figure 6-7] The side illuminators and top illuminators are shown. [Modes for carrying out the invention]

[0047] Referring to the attached drawing, the number 1 indicates an apparatus for analyzing a cap, for example, a plastic cap T. The plastic cap (or simply cap) extends around its respective longitudinal axis L. The cap is provided with a mark and a slit. The slit is preferably formed on the side SL of the cap T. The side SL of the cap T extends around the longitudinal axis L between a first end SL' and a second end SL''. The cap T also has a cross section ST connected to the side SL (for example, connected to the first end of the side SL) and oriented perpendicular to the longitudinal axis L. The mark is located on the inner surface of the cap (usually the mark is located on the bottom surface of the cap; in some cases the mark may also be located on the inner surface of the side wall of the cap). The side SL of the cap T includes a bonding zone U having a slit and / or one or more narrow-thickness zones. The bonding zone U defines the body C of the cap T and the tamper-evident strip BG. Since the cut is intermittent, the body is connected to the tamper-evident strip by a link, i.e., a zone of the cap that does not have a cut (or narrow-thickness zone). The link may be temporary, i.e., a link configured to break when the user first twists the cap T off the container. In this case, the body C of the cap T and the tamper-evident strip are permanently separated. Furthermore, or alternatively, the link may be permanent (in this case, also known as a “tether”), i.e., a link configured to allow the body to move away from the tamper-evident strip. In this case, the body and the tamper-evident strip remain attached to each other by a permanent link.

[0048] The apparatus 1 includes a conveyor 2 for transporting caps along a path P, the path P including a substantially straight section. In one embodiment, the conveyor 2 is a belt. The conveyor 2 is configured to hold (i.e., support and hold) the caps T in place while they are being transported along the path P.

[0049] Preferably, the conveyor 2 is configured to hold the cap T on the conveyor 2 by suction. The cap T may be positioned on the conveyor 2 such that its cross-section is in contact with the conveyor, or so that the second end of its side surface SL is in contact with the conveyor 2. On the conveyor 2, the cap is positioned with its top surface facing upward.

[0050] In one embodiment, the conveyor 2 includes a supply unit configured to receive an ordered sequence of caps T to be inspected from a supply device, the supply device being part of the cap T manufacturing system. In another embodiment, the conveyor 2 includes a discharge unit configured to supply a sequence of inspected caps T to a discharge device, the discharge device being part of the cap T manufacturing system.

[0051] Conveyor 2 transports the cap to a first inspection position IP1. At this position, the longitudinal axis L of the cap is aligned with the first inspection axis AI1. In other words, at the first inspection position IP1, the longitudinal axis L of the cap coincides with the inspection axis. Conveyor 2 also transports the cap to a second inspection position IP2. At this position, the longitudinal axis L of the cap is aligned with the second inspection axis AI2.

[0052] In one example, conveyor 2 is configured to transport caps individually along a path. Along the path, the caps are placed at a predetermined distance from each other. Furthermore, in one example, the conveyor includes a plurality of holes 201 along it. Each hole is provided with a suction means. In one example, the holes are arranged in two or more rows along the conveyor. The rows extend along the path and are arranged parallel to each other and spaced apart. Furthermore, the rows (and therefore the holes) are spaced apart from each other so that at least two holes act on the same cap simultaneously. Thus, the conveyor can be configured so that the angular position of the caps remains the same along the path P. Furthermore, in the inspection section, which includes the inspection zone (the section of the conveyor where the caps are placed at the first and second inspection positions), the section of the conveyor adjacent to the inspection zone and upstream of the inspection zone, and the section of the conveyor adjacent to the inspection zone and downstream of the inspection zone, the caps are held with greater force by suction from the suction means than in other sections of the conveyor. This solution makes it possible to hold the caps at the same angular position while they are being inspected at the first and second inspection positions. Furthermore, the conveyor may be provided with multiple guides arranged along the inspection section. The guides may be wheel guides. The guides may be arranged vertically or horizontally.

[0053] The device 1 includes an upper camera 3. The upper camera 3 is configured to observe the cap from above at a first inspection position IP1. In particular, the upper camera observes the cap according to an optical path oriented along the first inspection axis AI1. Therefore, the image acquisition axis of the upper camera coincides with the first inspection axis. The upper camera captures an image of the inner surface of the cap.

[0054] Apparatus 1 includes an upper illuminator 4. The upper illuminator is configured to illuminate a cap positioned at a first inspection location from above with a beam of light directed along a first inspection axis. In particular, the upper illuminator includes an illumination ring. The illumination ring is positioned horizontally. The ring is provided with multiple illumination elements LE1 (e.g., LEDs). The illumination elements are arranged throughout the entire inside of the illumination ring. The illumination elements generate a beam of light directed along a horizontal plane.

[0055] The upper illuminator 4 includes a waveguide that transmits light rays from the illuminating element LE1 along the longitudinal axis (or in a direction aligned with the first inspection axis).

[0056] The first and second inspection axes are perpendicular to the path P of the conveyor 2, particularly to the straight portion of the path P.

[0057] The device 1 is equipped with multiple side cameras 5. The side cameras are positioned laterally with respect to the second inspection axis AI2 and are positioned at an angle away from the second inspection axis. Furthermore, the side cameras 5 are oriented laterally with respect to the second inspection axis so as to observe the cap of the second inspection position from the side. In particular, the images obtained by the side cameras are images of the side surface SL of the cap T of the second inspection position. Each camera 5 defines an imaging axis R that is inclined with respect to a plane perpendicular to the second inspection axis AI2.

[0058] The apparatus includes a side illuminator 6 configured to illuminate the side SL of the cap T positioned at a second inspection location.

[0059] The side illuminator comprises a side wall 601 extending around the second inspection axis AI2, the side wall 601 preferably having a cylindrical shape and defining the range of the internal volume. The side wall preferably extends perpendicularly from the illumination ring.

[0060] The side illuminator 6 includes an upper wall 602 connected to the side wall 601 to define the upper range of the internal volume.

[0061] The side illuminator 6 includes an inlet opening 603 formed in the side wall 601 to allow the cap T to move into the internal volume, and an outlet opening 604 to allow the cap T to move out of the internal volume. The side wall 601 of the illuminator includes a plurality of openings 605 surrounding the second inspection axis. Each camera 5 is positioned in one of the multiple openings in the side wall 601 to frame the side SL of the cap T. The openings 605 are preferably arc-shaped.

[0062] The side wall has teeth TO, each having a first portion extending horizontally and a second portion extending downward from the first portion toward the conveyor. The first portion is located near the top of the conveyor where the cap is placed, and the second portion is located near the side of the conveyor.

[0063] In particular, the conveyor 2 is configured to transport the cap T between the inlet opening 603 and the outlet opening 604 via a second inspection axis. It should be noted that the second inspection axis is located within the internal volume of the side illuminator 6.

[0064] The inspection axis defines the inspection zone in which cap T is positioned for inspection.

[0065] The side wall 601 of the side illuminator 6 includes a diffuser body configured to diffuse light into the internal space of the side illuminator. The side illuminator 6 includes a primary light source. The primary light source includes a plurality of side illuminating elements LE2, for example, a plurality of LEDs. The side illuminating elements LE2 generate vertical light rays. Therefore, the side illuminating elements may be positioned at a 90° angle to the illuminating element LE1 of the upper illuminator 4. Furthermore, the illuminating element LE1 of the upper illuminator and the side illuminating elements LE2 may be offset vertically. The diffuser body has a ring-shaped configuration and extends along the side wall 601 of the side illuminator 6. The primary light source is positioned along the upper end of the diffuser body so that the diffuser body diffuses light from the primary light source into its internal volume. The side illuminating elements are distributed across the entire surface of the upper end of the diffuser body. The diffuser body is preferably made of a methacrylate material.

[0066] The side illuminator includes a reflective layer configured to reflect light, preferably a reflective film or a layer with minute slits. The reflective layer is located on the outer surface of the diffuser body, which is opposite to the inner surface facing the internal volume of the side illuminator. The reflective surface faces the internal volume and reflects light rays directed towards the reflective layer. The reflective layer extends along the side wall of the side illuminator.

[0067] The side illuminator may include a collimator configured to parallelize light emitted toward the first inspection axis. The collimator includes first and second collimating filters oriented at 90° to each other to define a collimating grid. The collimator is interposed between the second inspection axis and the diffuser body of the side illuminator and extends around the second inspection axis. The collimator is preferably located on the inner surface of the diffuser body so that the light rays diffused by the diffuser body are collimated radially perpendicular to the second inspection axis.

[0068] Device 1 includes a control unit. The control unit is configured to sequentially and selectively operate the upper illuminator 4 and the side illuminator 6 such that the side illuminator is turned on and the upper illuminator is turned off at a first time point, and the upper illuminator is turned on and the side illuminator is turned off at a second time point. The control unit is also configured to command the side camera to take a first image at a first time point, and to command the upper camera to take a second image at a second time point. The first time point precedes the second time point, or the second time point precedes the first time point. The control unit is also programmed to process the first and second images to verify the relative angular position of the gap with the corresponding marks.

[0069] Each image captured by the side camera represents a different part of the side SL. The control unit is programmed to derive an unfolded image from each image captured by the side and top cameras, which shows the side SL of the cap T as represented on a plane and the inner surface of the cap where the marks are located. The control unit is programmed to set a predetermined time interval between the first time point and the second time point.

[0070] The apparatus 1 also includes a position sensor configured to detect a position signal representing the position of the cap T at a predetermined position upstream of the first and second inspection positions. The control unit receives the position signal and commands the upper camera 3 and side camera 5 to take first and second images based on the position signal. In particular, the conveyor speed is known and input to the control unit. Thus, based on the speed of the conveyor 2 and the position of the cap on the conveyor 2 detected by the position sensor, the control unit calculates the time until the cap reaches the first and second inspection positions, thereby obtaining the first and second time points. Thus, the position of the cap on the conveyor makes it possible to derive the time points at which the illuminators and the side and upper cameras must be activated. In one example, at least the illuminator that is activated first includes a strobe light. Preferably, the upper and side illuminators include strobe lights. In a preferred embodiment, the upper camera, upper illuminator, multiple side cameras and side illuminators are located at the inspection station ST. At the inspection station ST, the cap is at the first and second inspection positions. In this example, the upper and side illuminators are configured to illuminate the inspection volume surrounding the cap of the inspection station. In this example, the upper and side illuminators are therefore located on the same station and illuminate the same inspection volume. In this example, at least the illuminator that is activated first has a strobe light.

[0071] In another example, a side illuminator and side camera are located at a first inspection station ST1 where the cap is in a first inspection position, and a top illuminator and top camera are located at a second inspection station ST2, located along a conveyor away from the first inspection station, where the cap is in a second inspection position. In this example, the side illuminator is configured to illuminate a first inspection volume, and the top illuminator is configured to illuminate a second inspection volume, which is different from the first inspection volume. In this example, the first inspection axis is therefore not surrounded by the side wall 601.

[0072] The apparatus 1 includes a screening element 7 located in the internal volume of the side illuminator, the screening element 7 extending in a plane that crosses the second inspection axis and is aligned with the second inspection axis, and the cap T is interposed between the conveyor 2 and the screening element 7 at the first and second inspection positions.

[0073] The device 1 includes a support cylinder 8 that is inserted into the upper wall housing and extends between a first end 4a and a second end.

[0074] The first end of the support cylinder is inserted into the upper wall housing so that the support cylinder can slide, and the second end is connected to the screening element 7. The support cylinder is aligned with the second inspection axis and slides along the inspection axis I to change the distance between the screening element 7 and the cap T.

[0075] The support cylinder 8 may have an opening (for example, formed in the screening element 7), and the upper camera 3 may be located in that opening. The upper camera 3 may be supported by a support member of the support cylinder. In an example where the upper camera is located in a second inspection station different from the first inspection station where the multiple side cameras are located, the upper camera may be located in its opening in the support cylinder and therefore surrounded by the support cylinder.

[0076] The apparatus 1 may include a fixing element configured to secure a support cylinder in a predetermined position along the inspection axis. The fixing element may include a clamp and a set screw.

[0077] Device 1 includes a mounting assembly configured to support a side illuminator. The mounting assembly includes a mounting flange connected from the outside (relative to the internal volume of the side illuminator) to the side wall 601 of the side illuminator 6. The mounting assembly (in particular the mounting flange) is configured to support a plurality of cameras surrounding a second inspection axis.

[0078] The side illuminator 6 is configured to slide along the inspection axis relative to the mounting flange and to adjust its height for multiple side cameras. The mounting flange is also connected to the mounting wall of the mounting assembly, surrounding the second inspection axis and located outside the side illuminator. The mounting assembly includes fixing elements, including mounting clamps and mounting screws, for securing the side illuminator in place along the second inspection axis relative to the mounting assembly.

[0079] In one embodiment, the device 1 includes a box configured to shield the side illuminator from light coming from outside the side illuminator. The box has an inlet and an outlet for the conveyor 2, located at the inlet and outlet openings in the side wall of the side illuminator, respectively. The box includes a pair of hand grips. [Prior art documents] [Patent Documents]

[0080] [Patent Document 1] WO2022175824 [Patent Document 2] 102020000012214 [Patent Document 3] JPH09169392A

Claims

1. An apparatus (1) for analyzing a plastic cap (T), wherein the cap extends around its respective longitudinal axis (L), the cap is provided with marks and cuts, the cuts are on the side surface (SL) of the cap, and the apparatus is - A conveyor (2) configured to transport the cap (T) along a path (P) to a first inspection position (IP1) where the longitudinal axis of the cap is aligned with a first inspection axis (AI1), and to a second inspection position (IP2) where the longitudinal axis of the cap is aligned with a second inspection axis (AI2), - An upper camera (3) configured to observe the cap located at the first inspection position (IP1) from above, in accordance with an optical path oriented along the first inspection axis (AI1), - An upper illuminator (4) configured to illuminate the cap positioned at the first inspection position from above with a light ray directed along the first inspection axis, -In order to observe the cap positioned at the second inspection position from the side, a plurality of side cameras (5) are arranged laterally with respect to the second inspection axis (AI2), and are positioned angularly apart from each other around the second inspection axis and oriented laterally with respect to the second inspection axis, - A side illuminator (6) configured to illuminate the side surface (SL) of the cap (T) positioned at the second inspection location, - A control unit, - The upper illuminator and the side illuminator are operated sequentially and selectively such that at the first time, the side illuminator is turned on and the upper illuminator is turned off, and at the second time, the upper illuminator is turned on and the side illuminator is turned off. The side camera is commanded to take a first image at the first time point, and the upper camera is commanded to take a second image at the second time point. Apparatus (1) comprising a control unit configured to process the first image and the second image and to verify the relative angular position between the gap and the respective marks corresponding thereto, wherein the first time point precedes the second time point, or the second time point precedes the first time point.

2. The apparatus (1) according to claim 1, wherein the control unit is programmed to set a predetermined time interval between the first time point and the second time point.

3. The apparatus (1) according to claim 1 or 2, wherein the conveyor is configured to transport the caps individually along the path, and the caps are arranged at a distance from each other along the path according to a predetermined distance.

4. The apparatus (1) according to any one of claims 1 to 3, comprising a position sensor configured to detect a position signal representing the position of the cap (T) at a predetermined position located upstream of the first and second inspection positions, wherein the control unit receives the position signal and commands the upper camera and the side camera to capture the first and second images based on the position signal.

5. The apparatus (1) according to any one of claims 1 to 4, wherein the conveyor includes a plurality of holes (201) along the conveyor, each hole is provided with a suction means, and the holes are spaced apart from each other such that at least two holes act on the same cap simultaneously.

6. The apparatus (1) according to any one of claims 1 to 5, wherein the upper illuminator and the side illuminator are equipped with strobe lights.

7. The apparatus (1) according to any one of claims 1 to 6, wherein the upper camera, the upper illuminator, the plurality of side cameras, and the side illuminators are arranged in an inspection station (ST) where the cap is in the first and second inspection positions, and the upper illuminator and the side illuminators are configured to illuminate the inspection volume surrounding the cap in the inspection station.

8. The apparatus (1) according to claim 7, wherein the illuminator configured to illuminate the volume of the inspection station at one of the first and second time points, which precedes the other of the first and second time points, includes a strobe light.

9. The apparatus according to any one of claims 2 to 6, wherein the side illuminator and the side camera are located at a first inspection station (ST1) where the cap is in the first inspection position, and the upper illuminator and the upper camera are located at a second inspection station (ST1) located along the conveyor away from the first inspection station where the cap is in the second inspection position, the side illuminator is configured to illuminate a first inspection volume, and the upper illuminator is configured to illuminate a second inspection volume different from the first inspection volume.

10. The apparatus according to any one of claims 1 to 9, wherein the side illuminator comprises a side wall (601) extending around the second inspection axis (AI2) and an upper wall (602) coupled to the side wall that defines the upper range of the internal volume defined by the side wall.

11. The apparatus according to claim 10, wherein the side wall has a cylindrical shape.

12. The apparatus according to claim 10 or 11, wherein the side illuminator comprises an inlet opening (603) formed in the side wall (601) for allowing the cap (T) to move into the internal volume, and an outlet opening (604) for allowing the cap to move out of the internal volume.

13. The apparatus according to any one of claims 10 to 12, wherein the side wall of the illuminator has a plurality of openings (605) surrounding the second inspection axis, and each of the plurality of side cameras is positioned in one of the plurality of openings in the side wall to frame the side (SL) of the cap.

14. The apparatus according to any one of claims 10 to 13, wherein the side wall has teeth (TO), and the teeth have a first portion extending horizontally and a second portion extending downward from the first portion toward the conveyor.

15. The apparatus according to claim 14, wherein the first part is positioned near the top of the conveyor on which the cap is placed, and the second part is positioned near the side of the conveyor.

16. The apparatus according to any one of claims 1 to 15, wherein each camera (5) of the plurality of side cameras defines an imaging axis (R) that is inclined with respect to a plane perpendicular to the second inspection axis (AI2).

17. A method for analyzing a plastic cap (T), wherein the cap extends around its respective longitudinal axis (L), the cap is provided with marks and cuts, the cuts are provided on the side surface (SL) of the cap, and the method is: - A step of transporting the cap along the path (P) to a first inspection position (IP1) where the longitudinal axis of the cap is aligned with a first inspection axis (AI1), and to a second inspection position (IP2) where the longitudinal axis of the cap is aligned with a second inspection axis (AI2), - A step of observing the cap located at the first inspection position (IP1) from above through the upper camera (3) in accordance with an optical path oriented along the first inspection axis, - A step of illuminating the cap positioned at the first inspection location from above using an upper illuminator (4) with a light ray directed along the first inspection axis, - A step of observing the cap positioned on the second inspection axis from the side through a plurality of side cameras (5) positioned laterally to the second inspection axis, which are arranged angularly apart from each other around the second inspection axis and oriented laterally to the second inspection position toward the second inspection axis, - A step of illuminating the side surface of the cap using a side illuminator (6), - A step of sequentially and selectively operating the upper illuminator and the side illuminator such that at a first time, the side illuminator is lit and the upper illuminator is turned off, and at a second time, the upper illuminator is lit and the side illuminator is turned off. - A step of commanding the side camera to take a first image at the first time point, and commanding the upper camera to take a second image at the second time point, wherein the first time point precedes the second time point, or the second time point precedes the first time point. A method comprising the steps of processing the first image and the second image to verify the relative angular position between the gap and the respective marks corresponding to it.

18. The method according to claim 17, further comprising the step of setting a predetermined time interval between the first time point and the second time point.

19. The method according to claim 17 or 18, comprising the step of transporting the caps individually along the path, wherein the caps are arranged at a distance from each other along the path according to a predetermined distance.

20. - A step of detecting a position signal representing the position of the cap (T) at a predetermined position located upstream of the first and second inspection positions, The method according to any one of claims 17 to 19, comprising the step of instructing the upper camera and the side camera to take the first and second images based on the position signal.

21. The method according to any one of claims 17 to 20, wherein a strobe light is used in the step of illuminating the cap from above and illuminating the side surface of the cap.

22. The method according to any one of claims 17 to 21, wherein the upper camera, the upper illuminator, the plurality of side cameras and the side illuminators are positioned in an inspection station (ST) where the cap is in the first and second inspection positions, the upper illuminator and the side illuminators illuminate the inspection volume surrounding the cap in the inspection station, and the illuminator illuminating the inspection station volume at one of the first and second time points, which precedes the other of the first and second time points, includes a strobe light.

23. The method according to any one of claims 17 to 22, wherein the side illuminator and the side camera are located at a first inspection station (ST1) where the cap is in the first inspection position, and the upper illuminator and the upper camera are located at a second inspection station (ST2) located along the conveyor away from the first inspection station where the cap is in the second inspection position, the side illuminator illuminates a first inspection volume, and the upper illuminator illuminates a second inspection volume different from the first inspection volume.

Images