Holding device and method

Abstract

A holding device (10) for holding an object having at least one flat surface comprises a suction cup body (11) provided with a suction channel (13) and a flexible holding edge (14), wherein the holding edge (14) defines the annular end portion of the suction cup body (11).

Description

Technical Field

[0001] The present invention relates to a "suction cup" type holding device used to hold and then move an object having at least one substantially smooth flat surface. The device finds particular application in the glass sheet processing sector where the size and hence the weight of the glass sheets moved between one or more processing stations can be significant.

Background Art

[0002] In the flat and curved glass manufacturing sectors and in processes for processing such glass, "suction cup" type holding devices, hereinafter simply referred to as suction cups, are widely used to facilitate the holding, moving and positioning of the object being processed.

[0003] Various types of suction cups are well known with respect to their shape, construction material and use, and they comprise a cap-shaped upper body defining a chamber in which a vacuum is formed, a suction duct communicating with the chamber for the formation of the vacuum, and an edge constituting the end part of the body of the suction cup and being the first to contact the object to be held.

[0004] The body usually has a metal core of aluminum in order to withstand the stresses exerted on the suction cup by the weight and inertia of the object to be held. Generally, the exterior and the edge of the body can consist of the same material which can be nitrile, silicone, isoprene, Viton®, polyurethane, etc.

[0005] The use of conventional suction cups for holding glass and other materials having a particularly shiny surface often results in the formation of suction cup marks and traces which are usually not readily visible under normal conditions but become apparent under certain light conditions and are very clearly visible when condensation occurs on the surface on which the suction cup has acted.

[0006] The formation of traces can be explained by considering the morphology of the glass surface. Although the glass surface appears perfectly smooth, it actually has a series of numerous rough areas consisting of "peaks" and "valleys" at a microscopic level. When a suction cup adheres to the glass and when it is removed, dust particles and even material released by the suction cup become trapped in the valleys of the glass surface.

[0007] These particles are so small that they are indistinguishable to the naked eye under normal lighting conditions. However, they alter the optical properties of the glass, resulting in typical suction cup marks becoming clearly visible under certain lighting conditions. The wettability of the surface is also altered by these particles, causing small condensation droplets to behave differently in areas where suction cups have acted, clearly highlighting the usual marks.

[0008] To better understand the current technology described above, it is useful to examine how the bonding and separation of suction cups on the surface of a glass plate occur.

[0009] Referring to Figure 2a, the suction cup 100, which consists of a suction cup body 111, a retaining edge 114, a suction duct 113, and an insertion part 122, is located at a specific distance from the glass plate L. In this state, it is not possible to induce a vacuum and attach the suction cup to the glass plate.

[0010] In Figure 2b, the retaining edge 114 is in contact with the glass plate L, and when air suction is activated through the suction duct 113, the pressure inside the suction cup 100 decreases. At this point, the suction cup 100 is pressed toward the glass plate L by the higher external pressure, forming the state shown in Figure 2c. In this state, the suction cup 100 moves toward the glass plate L, and the retaining edge 114 moves along the sliding section s on the surface of the glass plate L.

[0011] This process continues until the insertion part 122 makes contact with the surface of the glass plate L (see Figure 2d).

[0012] The following is clear here: The retaining edge 114, transitioning from the state in Figure 2b to the state in Figure 2d, is in motion, and during this motion, the retaining edge 114 slides on the surface of the glass plate L equal to the entire sliding section s', accumulating any dust particles it may encounter and releasing the particles into the surface roughness of the glass plate L.

[0013] The aforementioned sliding motion significantly exacerbates phenomena that occur in relation to the insertion portion 122, although this is suppressed in the area of ​​mere static contact.

[0014] The accumulation of these particles in the "valleys" of surface roughness explains why conventional cleaning with various types of cleaning agents cannot solve the problem. Removal of these particles can only occur through polishing with abrasive paste to remove the material that has penetrated deep into the "valleys," that is, through the mechanical removal of the "peaks" of the surface.

[0015] If the phenomenon affects the entire area of ​​the suction cup, i.e., both the outer edge and the internal area where the stop insertion portion is located, it is useful to point out that the cause is primarily due to a lack of cleaning of the suction cup itself. In fact, common practice shows that the usual frequent and careful cleaning of the suction cup with a special solvent such as isopropyl alcohol can eliminate the appearance of suction cup marks caused by mere static contact between the suction cup material and the glass.

[0016] On the other hand, good cleaning practices cannot accurately address the phenomenon of circular marks appearing on the edges of the suction cups, as these marks are a result of the sliding action of the suction cup material against the glass.

[0017] It is clear that the materials constituting the suction cup, and especially the retaining edge, must not only ensure retention with the glass surface but also withstand excessive elastic deformation in order to transition from a resting state (Figure 2a) to an active state (Figure 2d). For this reason, the materials constituting the suction cup end up being as described above, despite being easily subjected to wear due to particle emission and friction against the glass.

[0018] In the first well-known solution, the suction cups used to hold the glass are covered with a special fibrous material to prevent the suction cup material from contacting the glass. These protective materials, generally referred to as one or more "covers," are widely used in flat glass processing sectors, but they have several disadvantages. The first of these disadvantages is a significant decrease in suction cup performance due to suboptimal sealing of the cover material, resulting in a decrease in the vacuum within the suction cup. However, most importantly, the first disadvantage is a significant decrease in suction cup performance, particularly when the suction cups are used for transport, i.e., when they are subjected to stress parallel to the glass surface, due to a decrease in the coefficient of friction of the protective material with respect to the usual material used for the suction cups. All of this leads to the need to use larger suction cups and / or increase their number. Another disadvantage of cover protective materials is that they need to be replaced daily or more frequently due to the premature deterioration of the materials that constitute them.

[0019] Other well-known solutions propose a cloth cover for the edges of the suction cup, leaving the center of the suction cup open. However, in this embodiment, friction remains between the cloth cover and the glass surface because the protective material is integrated with the edges of the suction cup. This does not eliminate the risk of particles being released onto the glass surface, or of dust particles already present on the glass moving towards the "valleys" of the surface. Furthermore, since the edge cover is made of breathable cloth, some degree of vacuum reduction inside the suction cup must be taken into consideration.

[0020] Other well-known solutions describe silicone protectors that are placed around the edge of the suction cup to separate the edge of the suction cup from the glass surface. This solution solves the problem of vacuum drop, but the limitations of the aforementioned solutions remain unchanged.

[0021] Patent Document 1 describes a suction cup for holding and moving objects, particularly objects having a flexible surface such as a lithograph plate or printing plate. The suction cup is provided with a flexible sheet that acts as a barrier between the contact flange of the suction cup and the object being held and handled. In this document, the flexible sheet, depending on how its size and structure are determined, hinders strong adhesion to the object. This limits the use of this suction cup to applications involving only lightweight and delicate objects.

[0022] Therefore, in order to overcome at least one of the disadvantages of the current technology, there is a need to perfect the holding devices and methods, particularly for glass plates, but not just for those plates.

[0023] One object of the present invention that addresses the technical problem the applicant seeks to solve is to provide a device for holding an object having at least one smooth, flat surface, such as a glass plate, and to complete a corresponding method, which eliminates or at least significantly reduces the phenomenon of surface marks caused by contact with the suction cup, without significantly affecting the performance of the suction cup, that is, while maintaining its load capacity particularly in a direction parallel to the surface of the object being held.

[0024] Another objective of the present invention is to provide a holding device that is easy and economical to manufacture and does not require frequent replacement or intervention for maintenance, thereby ensuring the continuity of the manufacturing flow.

[0025] Another object of the present invention is to provide a holding device that can be easily and quickly cleaned.

[0026] The applicant invented, tested, and realized the present invention in order to overcome the drawbacks of the prior art and achieve these and other objects and advantageous effects.

Prior Art Documents

Patent Documents

[0027]

Patent Document 1

Summary of the Invention

[0028] The present invention is defined and characterized in the independent claims. The dependent claims describe other features of the present invention or variations to the idea of the main invention.

[0029] In accordance with the above object, in order to solve the above-disclosed technical problems in a novel and inventive manner and further achieve remarkable advantageous effects as compared with the prior art, a holding device for holding at least one object having a preferably smooth flat surface according to the present invention comprises a suction channel and a suction cup body provided with a flexible holding edge defining an annular end portion of the suction cup body.

[0030] According to one aspect of the present invention, the holding device comprises a protective element configured to be associated with the suction cup body and at least partially accommodate the holding edge in a sliding manner in an annular shape, the protective element being interposed between the holding edge and the flat surface.

[0031] By doing so, sliding contact between the holding edge and the flat surface of the object to be held is avoided, and thus the formation of suction cup marks and traces is avoided. The protective element remains in a fixed position when in contact with the object to be held, i.e., it does not slide or slip and constitutes only static-type contact, while the flexible holding edge can slide within the protective element. In fact, the holding edge can stretch or deform inside it and is not integrated with the protective element.

[0032] According to another aspect of the present invention, the protective element is inserted only around the retaining edge. This configuration improves the adhesion of the suction cup to the object to be held. This proves particularly advantageous when it is necessary to support heavy objects, such as glass plates.

[0033] According to another aspect of the present invention, the protective element is inserted in a manner that allows it to be detachably attached around the retaining edge.

[0034] According to another aspect of the present invention, the protective element has a shape substantially corresponding to the shape of the peripheral profile of the retaining edge. In one embodiment of the present invention, the retaining element is a ring. According to a possible embodiment, the retaining element is a ring that may have a circular, elliptical, or polygonal shape.

[0035] According to another aspect of the present invention, the protective element has a lateral wall bent at a predetermined angle and defines an annular pocket capable of accommodating at least a portion of the retaining edge.

[0036] According to another aspect of the present invention, the pocket has a predetermined three-dimensional structure independent of the lateral position of the retaining edge. In other words, the pocket has a rigid three-dimensional structure that does not conform to the retaining edge when the retaining edge deforms during the operation of the device.

[0037] According to another aspect of the present invention, the side wall is formed by an oblique portion and a flat portion formed by an annular plate.

[0038] According to another aspect of the present invention, the flat portion is positioned externally with respect to the overall dimensions of the center of the suction cup body in which the suction channel is formed.

[0039] According to another aspect of the present invention, the central area of ​​the flat portion has an open central area that is slightly smaller than the area of ​​the bottom wall of the suction cup body facing the flat surface of the object during use.

[0040] According to another aspect of the present invention, the ratio of the bottom wall region to the open central region is approximately 1.1 to approximately 1.3. According to another aspect of the present invention, the side walls have an inner radius size less than the outer radius size of the retaining edge. In this aspect, the retaining edge holds the protective element in place without requiring any specific coupling means.

[0041] According to another aspect of the present invention, the protective element is made of a dense material without voids. This minimizes the loss of vacuum during the operation of the retaining device.

[0042] According to another aspect of the present invention, the protective element is made of a thermoplastic or thermosetting material.

[0043] Some embodiments of the present invention are methods for holding an object having at least one flat surface, - A step of making available a suction cup body provided with a suction channel and a flexible retaining edge, wherein the retaining edge defines the annular end portion of the suction cup body, - A step of associating a protective element with the suction cup body for at least partially accommodating a retaining edge defining the retaining device in an annular and sliding manner, - A step of moving the retaining device closer until the protective element contacts a flat surface, - A step of generating a vacuum between the suction cup body and the object by a suction means fluidly connected to the suction channel, Regarding methods for providing such a system. [Brief explanation of the drawing]

[0044] [Figure 1a] This shows a schematic cross-sectional view of the holding device according to the present invention in a resting state. [Figure 1b] This shows a schematic cross-sectional view of the holding device according to the present invention in its operating state. [Figure 2a] This shows a schematic sequence of operations for a holding device using current technology. [Figure 2b] This shows a schematic sequence of operations for a holding device using current technology. [Figure 2c]This shows a schematic sequence of operations for a holding device using current technology. [Figure 2d] This shows a schematic sequence of operations for a holding device using current technology. [Modes for carrying out the invention]

[0045] These and other aspects, features and advantageous effects of the present invention will become apparent from the following description of embodiments given as non-limiting examples with reference to the accompanying drawings.

[0046] We must make the following clear: Since the scope of protection is defined by the claims, the expressions and terminology used in this description, as well as the figures in the accompanying drawings, serve only to better illustrate and describe the present invention, and their purpose is to provide non-limiting examples of the invention itself.

[0047] For ease of understanding, where possible, the same reference numerals are used to identify identical common elements in the drawings. It is understood that elements and features of one embodiment may be combined with or incorporated into other embodiments as appropriate, without further explanation.

[0048] Referring to Figures 1a to 1b, the holding device 10 according to the present invention for holding and subsequently moving an object having at least one substantially smooth flat surface, such as a glass plate L, comprises a suction cup body 11 provided with a suction duct 13 that opens outward in the direction of the object to be held, and a flexible holding edge 14 that defines the annular end portion of the suction cup body 11.

[0049] The holding device 10 includes, or is associated with, a suction means (not shown) fluidly connected to a suction duct 13 to generate a vacuum in the gripping area defined by the holding edge portion 14.

[0050] The holding device 10 according to the present invention includes a protective element 15 that is annularly associated with the suction cup body 11 and configured to accommodate the holding edge 14 in a sliding manner, the protective element 15 being interposed between the holding edge 14 and the glass plate L.

[0051] In other words, the loose connection between the retaining edge 14 and the protective element 15 allows for relative movement between them, particularly between the retaining edge 14 (elastically deformable portion) and the protective element 15 (fixed portion).

[0052] The term "ring-shaped" and its derivatives do not necessarily mean a circular profile, but can refer to any profile with a closed periphery and an open center, which may have circular, elliptical, or polygonal shapes.

[0053] The protective element 15 has a shape that substantially corresponds to the peripheral profile of the retaining edge 14. Therefore, if the retaining edge 14 is circular, the protective element 15 will also be circular. In the embodiments shown in Figures 1a and 1b, the protective element 15 is a protective ring or collar.

[0054] The annular shape of the protective element 15 prevents the holding edge 14 from directly contacting the plate L and thus avoids the formation of marks, as will become clearer in the following description, by ensuring that no physical obstructions that could reduce the gripping effect are interposed between the suction duct 13 and the glass plate L. This also allows the load capacity of the holding device 10 to be maintained in a direction parallel to the surface of the plate L that is being held and possibly moved.

[0055] The suction cup body 11 has a central part 20 through which the suction duct 13 passes, and the suction duct 13 extends between the upper wall 20c and the bottom wall 20b around the central axis X of the suction cup body 11.

[0056] The central part 20 may, for example, have a cylindrical shape. On the other hand, those skilled in the art will understand that the shape of the central part 20 is not limited to the circular shape shown in Figures 1a and 1b.

[0057] The retaining edge 14 extends around the central part 20 in a direction that moves laterally away from the central axis X. The lateral extension of the retaining edge 14 is greater than the lateral extension of the central part 20.

[0058] The retaining edge 14 consists of a substantially flexible, i.e., elastically deformable annular wall. The flexible annular wall may have a cross-section that narrows as it moves away from the central axis X, i.e., away from the central part 20.

[0059] The retaining edge portion 14 extends from the lateral wall 20a of the central portion 20 corresponding to the bottom wall 20b, defining continuity with the bottom wall 20b.

[0060] According to the present invention, the protective element 15 is detachably inserted around the retaining edge 14. The protective element 15 can be easily inserted (pulled out) around the retaining edge 14 by an insertion (pulling out) motion along the central axis X, by utilizing the elasticity of the material of the retaining edge 14.

[0061] The shape and size of the protective element 15 are such that the retaining edge 14 is accommodated in a sliding manner in all operating states of the retaining device 10.

[0062] The protective element 15 has a lateral wall 16 bent at a predetermined angle and defines an annular pocket 17 capable of accommodating at least partially the retaining edge 14.

[0063] The wall 16 can be bent at an angle α ranging from approximately 10 degrees to approximately 20 degrees, for example, approximately 15 degrees.

[0064] The pocket 17 has a predetermined three-dimensional structure, independent of the lateral position of the retaining edge 14.

[0065] In other words, in any operating state of the holding device 10, the pocket 17 maintains its shape, while the holding edge 14 can elastically deform within the pocket 17. Therefore, when the holding edge 14 bends to flatten parallel to the flat surface of the glass plate L, the pocket 17 does not deform, at least macroscopically.

[0066] The pocket 17 is open in the direction of the central axis X to allow insertion of the retaining edge 14, which can slide inside it. During the transition from the resting state to the active state, sliding contact occurs between the retaining edge 14 and the protective element 15, while the protective element 15 is in static contact with the glass plate L.

[0067] The lateral wall 16 has an inner radius size less than the outer radius size of the retaining edge 14. In this embodiment, even when the retaining device 10 is idle, the protective element 15 is sustainably supported by the retaining edge 14 substantially by interference.

[0068] The lateral wall 16 is formed by an oblique portion 16a inclined at an angle of less than 90 degrees with respect to the central axis X, and a flat portion 16b substantially perpendicular to the central axis X.

[0069] The slanted portion 16a is located above the flat portion 16b and has an inclination that determines interference with the retaining edge portion 14.

[0070] The flat portion 16b defines an annular plate configured to contact the glass plate L when the holding device 10 is in operation, and to substantially prevent sliding contact between the holding edge portion 14 and the glass plate L.

[0071] The annular flat portion 16b is left completely open in its central area. Therefore, the bottom wall 20b of the central part 20 of the suction cup body 11 directly faces the glass plate L. Consequently, the suction duct 13 does not encounter any physical obstacles in front of the glass plate L, and the grip on the glass plate L is always optimal.

[0072] The central region of the flat portion 16b may have an open central region A1 that is slightly smaller than region A2 of the bottom wall 20b. In Figures 1a and 1b, these regions are shown as extensions of straight lines in the side view. This means that the central region of the flat portion 16b is almost completely open, giving the bottom wall 20b the possibility of acting with almost the entire useful surface of the bottom wall 20b on the flat surface of the object to be held.

[0073] The ratio of region A2 of the bottom wall 20b to the open central region A1 can range from approximately 1.1 to approximately 1.3.

[0074] The presence of the protective element 15 means that the glass plate L is subjected only to static contact with the protective element 15 and the bottom wall 20b, and since the protective element 15 and the bottom wall 20b are substantially close to the glass plate L in the axial direction, neither of them slides during the coupling stage. The only lateral movement is that of the retaining edge 14, but this occurs within the pocket 17 and not with respect to the glass plate L.

[0075] The protective element 15 is made of a dense material with no "voids." In other words, the protective element 15 is made of a gas-impermeable material, and therefore the loss of vacuum during the operation of the holding device 10 can be minimized.

[0076] The protective element 15 is made of a plastic material that does not release particles due to friction during contact with the glass plate L.

[0077] The protective element 15 may be made of a thermoplastic or thermosetting material.

[0078] Thermoplastic materials can be selected from the group including polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyester (PS), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polyamide (PA), and polylactic acid (PLA).

[0079] Thermosetting materials can be selected from the group including polyester resins, phenolic resins, epoxy resins, and the like.

[0080] The holding device 10 may also include one or more insertion portions 22 that are associated with or form part of the suction cup body 11.

[0081] The insertion portion 22 is configured on or can be associated with the bottom wall 20b of the suction cup body 11.

[0082] The operation of the holding device 10 described above corresponds to the method according to the present invention, and is as follows: - A step to make usable a suction cup body 11 having a suction channel (suction duct) 13 and a flexible retaining edge 14, wherein the retaining edge 14 defines the annular end portion of the suction cup body 11, - The step of associating the protective element 15 with the suction cup body 11 so as to accommodate the retaining edge 14 in an annular shape, - The step of moving the holding device 10 until the protective element 15 contacts the flat surface of the glass plate L, thereby bringing it closer, - A step of generating a vacuum between the glass plate L and the retaining edge 14 by a suction means fluidly connected to the suction channel 13, It is equipped with.

[0083] In particular, as described above, once the holding device 10 is assembled and in contact with the glass plate L, the holding device 10 operates between a resting state and an active state.

[0084] In the idle state, the retaining edge 14 is inclined with respect to the central axis X, and the suction of air through the suction duct 13 is not activated.

[0085] In operation, air is drawn in through the suction duct 13, causing the retaining edge 14 located within the pocket 17 to elastically deform and flatten parallel to the flat surface of the glass plate L. During the deformation of the retaining edge 14, the protective element 15 becomes stationary relative to the flat surface of the glass plate L.

[0086] During operation, the bottom wall 20b of the central part 20 of the suction cup body 11 is in direct contact with the glass plate L without any obstructions or barriers.

[0087] As described above, it is clear that the holding device 10 and method may be modified in part and / or added to without departing from the field and scope of the present invention, as defined by the claims.

[0088] Although the present invention has been described with reference to some specific embodiments, it will also be apparent to those skilled in the art that other equivalent forms of retaining devices and corresponding methods can be achieved, all having the features described in the claims and thus falling within the field of protection defined by the claims.

[0089] In the following claims, the sole purpose of the symbols in parentheses is to facilitate their reading, and they should not be considered limiting factors with respect to the field of protection defined by the claims.

Claims

1. A holding device (10) for holding an object having at least one flat surface, comprising a suction cup body (11) provided with a suction channel (13) and a flexible holding edge (14), wherein the holding edge (14) defines the annular end portion of the suction cup body (11), A retaining device (10) comprising a protective element (15) configured to at least partially accommodate the retaining edge (14) in a sliding manner in an annular shape, the protective element (15) interposed between the retaining edge and the flat surface, wherein the protective element (15) is inserted only around the retaining edge (14).

2. The retaining device (10) according to claim 1, wherein the protective element (15) is inserted in a manner that allows it to be attached to or removed from the retaining edge (14).

3. The retaining device (10) according to claim 1 or 2, wherein the protective element (15) has a lateral wall (16) bent at a predetermined angle and defines an annular pocket (17) capable of accommodating at least partially the retaining edge (14).

4. The retaining device (10) according to claim 3, wherein the pocket (17) has a predetermined three-dimensional structure independent of the lateral position of the retaining edge (14).

5. The holding device (10) according to claim 3 or 4, wherein the lateral wall (16) is formed by an inclined portion (16a) and a flat portion (16b) formed by an annular plate.

6. The holding device (10) according to claim 5, wherein the flat portion (16b) is positioned externally to the overall dimensions of the central part (20) of the suction cup body (11) on which the suction channel (13) is provided.

7. The holding device (10) according to claim 5 or 6, wherein the central area of ​​the flat portion (16b) has an open central area (A1) that is slightly smaller than the area (A2) of the bottom wall (20b) of the suction cup body (11) that faces the flat surface of the object when in use.

8. The holding device (10) according to claim 7, wherein the ratio of the region (A2) of the bottom wall (20b) to the open central region (A1) is 1.1 to 1.

3.

9. The retaining device (10) according to any one of claims 3 to 8, wherein the lateral wall (16) has an inner radius size less than the outer radius size of the retaining edge (14).

10. The retaining device (10) according to any one of claims 1 to 9, wherein the protective element (15) is made of a dense material without voids.

11. The holding device (10) according to any one of claims 1 to 10, wherein the protective element (15) is made of a thermoplastic or thermosetting material.

12. The holding device (10) according to any one of claims 1 to 11, comprising one or more insertion portions (22) associated with or forming a part of the suction cup body (11).

13. A method for holding an object having at least one flat surface, A suction cup body (11) provided with a suction channel (13) and a flexible retaining edge (14), wherein the retaining edge (14) defines the annular end portion of the suction cup body (11), and a step of making the suction cup body (11) usable, The steps include associating a protective element (15) for at least partially housing the retaining edge (14) that defines the retaining device (10) in an annular shape, The steps include moving the retaining device (10) closer until the protective element (15) contacts the flat surface, The steps include generating a vacuum between the suction cup body (11) and the object by a suction means fluidly connected to the suction channel (13), A method for providing this.

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