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CN-122003596-A - System and method for analyzing caps assembled by a capping machine onto containers having support rings

CN122003596ACN 122003596 ACN122003596 ACN 122003596ACN-122003596-A

Abstract

A system (1) for analyzing caps (C) fitted by capping machines onto Containers (CO) having a Support Ring (SR), wherein the caps and the support ring have indicia oriented in correspondence with the origin of their respective threaded elements, comprises a conveyor (2) for individually conveying a series of caps-fitted Containers (CO) to an Inspection Position (IP) for orienting the containers along a predetermined longitudinal axis (L), an illuminator (3), a camera (4), an over-center or peripheral lens system located in front of the camera, a control unit for acquiring images of the caps and the support ring and programmed for processing the images to determine the angular position of the indicia on the caps and the support ring with respect to the longitudinal axis.

Inventors

  • MARCO CASADIO
  • Giovanni Almaloli

Assignees

  • 萨克米伊莫拉机械合作社合作公司

Dates

Publication Date
20260508
Application Date
20240801
Priority Date
20230802

Claims (18)

  1. 1. A system (1) for analyzing caps (C) assembled by a capping machine onto Containers (CO) having a Support Ring (SR), said caps (C) and said Support Ring (SR) having indicia oriented in correspondence with the origin of their respective threaded elements, said system comprising: -a conveyor (2) for individually conveying a series of said Containers (CO) fitted with respective caps (C) to an Inspection Position (IP) in which said Containers (CO) are oriented along a predetermined longitudinal axis (L); -an illuminator (3) configured for illuminating said Container (CO) located at said Inspection Position (IP) with a light beam directed along said longitudinal axis (L) towards said cover; -a camera (4) configured for observing the container located at the Inspection Position (IP) along an observation path oriented along the longitudinal axis towards the cover; -a lens system (5) located in front of the camera (4); A control unit connected to the camera for acquiring images of the cover and the support ring and programmed for processing the images to determine the angular position of the markers on the cover and the support ring relative to the longitudinal axis, Wherein the lens system comprises a super-central lens (501).
  2. 2. The system (1) according to claim 1, wherein the illuminator (3) is configured for illuminating the lens system (5) from above along the longitudinal axis (L).
  3. 3. The system (1) according to claim 2, wherein the illuminator (3) is configured for illuminating the lens system from above only along the longitudinal axis (L).
  4. 4. A system (1) according to claim 2 or 3, wherein the illuminator (3) comprises a collimator (6), the collimator (6) being for guiding light collimated parallel to the longitudinal axis (L) to the lens system (5).
  5. 5. The system (1) according to claim 4, wherein the luminaire (3) comprises an illumination panel having an array of illumination elements (301) uniformly distributed over the entire surface of the illumination panel, the surface area of the illumination panel being equal to or larger than the top surface of the lens system (5) so as to uniformly distribute the light beam over the top surface of the lens system.
  6. 6. The system (1) according to any of the preceding claims, wherein the over-center lens (501) is provided with an anti-reflection surface or is subjected to an anti-reflection treatment.
  7. 7. The system (1) according to any of the preceding claims, wherein the lens system comprises a plurality of over-center lenses (501) which cooperate with each other to form a multi-lens over-center lens system.
  8. 8. The system (1) according to any one of the preceding claims, wherein the control unit is programmed to take a single image for each of the containers fitted with the caps.
  9. 9. The system (1) according to any one of the preceding claims, wherein the luminaire comprises a collimator (6), the collimator (6) being for collimating light parallel to the longitudinal axis.
  10. 10. The system (1) according to any one of the preceding claims, comprising a beam splitter (7), the beam splitter (7) being located downstream of the illuminator to straighten light rays towards the cover in the inspection position.
  11. 11. A capping machine configured for applying caps (C) onto the necks of respective bottles (CO) by generating a closing torque for fastening the caps onto the necks via respective threads, the capping machine comprising a system (1) for analysing caps fitted onto containers, wherein the system is according to any one of the preceding claims.
  12. 12. A method for analyzing caps (C) assembled by a capping machine onto Containers (CO) having a Support Ring (SR), said caps (C) and said Support Ring (SR) having indicia oriented in correspondence with the origin of their respective threaded elements, said method comprising the steps of: -individually transferring a series of said Containers (CO) fitted with said caps (C) to an Inspection Position (IP) orienting said containers along a predetermined longitudinal axis (L); illuminating the Container (CO) at the Inspection Position (IP) with a light beam directed along the longitudinal axis (L) towards the cover; observing the Container (CO) at the Inspection Position (IP) along a viewing path coaxial with the longitudinal axis and directed towards the cover by a camera (4) and taking images of the cover and the support ring; processing the images by a control unit to determine the angular position of the markers on the cover and the support ring relative to the longitudinal axis; Providing a lens system (5) in front of the camera, Wherein the lens system comprises a super-central lens (501).
  13. 13. The method according to claim 12, wherein the lens system (5) is illuminated from above along the longitudinal axis (L), the lens system being interposed between the camera (4) and the container at the Inspection Position (IP).
  14. 14. The method of claim 13, wherein the lens system is illuminated with light collimated parallel to the longitudinal axis.
  15. 15. The method of claim 13 or 14, wherein the light beam is uniformly distributed over the top surface of the lens system.
  16. 16. The method of any of claims 12-15, wherein the over-center lens is subjected to an anti-reflection treatment.
  17. 17. The method of any of claims 12-16, wherein a single image is taken for each of the containers fitted with the lid.
  18. 18. The method according to any one of claims 12-17, wherein the support ring is provided with: A first mark; A second marker angularly spaced 180 degrees about the longitudinal axis relative to the first marker; a third indicia angularly spaced about the longitudinal axis relative to the first indicia by an angle ranging between 120 and 150 degrees.

Description

System and method for analyzing caps assembled by a capping machine onto containers having support rings Technical Field The present invention relates to a system and method for analyzing caps fitted by a capping machine to containers provided with a support ring, a capping machine, and a method for analyzing caps fitted by a capping machine to containers provided with a support ring. Background The present disclosure addresses the field of optical inspection systems applied in the bottling industry, in particular with reference to the inspection of the tightness of plastic caps with respect to the neck of the respective containers to which they are fitted. Typically, the caps are assembled by a capping machine that automatically screws each cap onto the corresponding container to apply a tightening torque to the cap. In some cases, the capping process may be performed incorrectly or in an undesirable manner, with the result that the container is not properly closed or is difficult to remove. These lid fastening defects constitute a problem for beverage suppliers. It should also be noted that in general, different caps require different tightening torques. Therefore, it is necessary to be able to find out whether the fastening torque is the correct torque for fastening the cover. To this end, a reference mark or indicia is applied to the cap and a support ring (also called a flange) provided at the level of the neck on the container, so that the angular position of the mark present on the neck and support ring can indicate that the cap is correctly positioned on the container. These identifiers are also known as Pull-Up marks (PUM). In this regard, patent documents US5321506, US6473169 and WO2014176287A1 provide examples of optical inspection systems for determining whether a cap has been properly secured on a container. US6473169 relates to the use of telecentric lenses. In this document it should be noted that if we want to see both the neck and the cap of the bottle in the same image we have to enlarge the field of view, but this would lead to an undesired reduction in resolution, and to avoid this problem US6473169 proposes to inspect the neck and cap at different positions on the conveyor carousel (turret). It should be noted that a telecentric lens (or objective lens) is a special optical lens whose entrance pupil or exit pupil, or both, are at infinity. The function of a telecentric lens is to eliminate perspective effects for a particular frame field and distance. Patent document WO2014176287A1 describes an optical inspection system intended to determine the angular position of a reference mark on the neck of a container and on a support ring. The system also involves acquiring two different images non-simultaneously and then comparing the images. A telecentric lens is also used in this case. However, the solutions proposed in these patent documents have some drawbacks. Firstly, they are particularly complex solutions and, moreover, they do not guarantee uniformity and reliability of the inspection accuracy in various possible applications. Patent document DE102021121489 describes another example of an inspection system, method and device for inspecting containers on which closures are provided. In particular, DE102021121489 describes a system for analyzing lids applied to containers equipped with support rings using a capping machine. DE102021121489 provides an illumination system comprising two illuminators enclosed by a wall that conveys light towards a lower diffusing wall, whereby the light is diffused and prevented from exiting laterally. DE102021121489 also includes a camera and a lens system between the camera and the container in the inspection position. In fact, there remains a need for an inspection system for inspecting the tightness of caps on containers that is both simple and capable of ensuring high precision and reliability for a variety of different applications. In this case, it should be noted that one of the problems is that the inspection accuracy tends to depend largely on the color of the cover. Furthermore, in the case of a liquid in a container having foam, the accuracy and reliability of the inspection system tend to be particularly low. In fact, the liquid or foam within the bottle may interfere with the identification of the identifier. In particular, the flange is usually made of transparent PET, for which reason the elements below the flange may be regarded as disturbances. Another problem that reduces the reliability of prior art inspection systems is that possible defects on the flange may be confused with logos that are also present on the flange. Disclosure of Invention It is an object of the present invention to provide a system and method for analyzing caps assembled by a capping machine onto a container provided with a support ring that overcomes the above-described drawbacks of the prior art. This object is fully achieved by the system and method of the present