Conveying system

Abstract

A conveying system (10) for conveying objects, comprising: a stationary sliding track (11) defining a continuous and uninterrupted sliding path; a moving unit (12) movable on the slide rail (11) in a travel direction (A); and a drive means for moving the moving unit (12) on the slide rail (11). The conveying system (10) comprises an inner rolling guide rail (16) and an outer rolling guide rail (17) which are respectively arranged on the inner side (30) and the outer side (31) of the sliding rail (11); and an inner rolling unit (18) and an outer rolling unit (19) configured to cooperate with the inner rolling guide (16) and the outer rolling guide (17), respectively, according to a rolling relationship.

Description

Technical Field

[0001] This invention relates to a system for conveying objects, particularly but not limited to conveying objects along a closed-loop path that includes both straight and curved segments. Preferably, the conveying system according to the invention provides a linear motor driven by electromagnetic force, but more generally, it can be advantageously applied to indexing or "stepping" moving belt / chain conveyor systems. Background Technology

[0002] In the field of industrial automation, automated conveyor systems that can transport objects (usually the transport of objects between different processing stations in an industrial processing line) are well known.

[0003] This conveying system includes a conveying component that defines the path along which the object moves.

[0004] In some solutions known in the art, the conveying member is configured as a belt, chain or other similar conveying component that is closed in a loop on at least a pair of pulleys, wherein at least one pulley is motorized and the movement of the conveying member is determined by its rotation, on which the object is placed.

[0005] In other solutions known in the art, the conveying component is configured as multiple conveying trolleys, each trolley supporting one or more objects and sliding on fixed linear guideways. The guideways include straight and curved sections designed to allow the trolleys conveying the objects to follow a predetermined path. An example of such a solution is described in the same applicant's European patent EP-B1-2544974, in which the conveying trolleys are guided by rollers on fixed guideways, and this patent describes a conveying system according to the preamble of independent claim 1.

[0006] A widely used technique in known solutions in the art is the technique of electromagnetically driven linear motors. This provides that each transport trolley includes a permanent magnet that engages with multiple electromagnets, the electromagnets being embedded in fixed guide rails positioned facing the permanent magnets, with a magnetic gap between them. The permanent magnets, in cooperation with the electromagnets, allow the transport trolley to be driven by selectively activating the electromagnets when a particular transport trolley is to be driven, and the resulting electromagnetic field causes the transport trolley to move according to patterns known in the art.

[0007] Conveyor systems using electromagnetically driven linear motors have long been used in many industrial sectors, such as product packaging, from primary to secondary packaging. In fact, these linear motors offer very high performance levels because they allow for high acceleration and independent control of the conveyor trolley's movement.

[0008] One drawback of traditional conveyor systems is the existence of numerous design constraints, particularly regarding the proper movement of the conveyor trolley within a closed path consisting of straight and curved sections. In fact, the geometry of the conveyor trolley is strictly dependent on the characteristics of the curved sections, especially their radii of curvature. It is easy to understand that the trolley must be able to follow the path continuously when transitioning from straight to curved sections.

[0009] Therefore, the transition of the conveyor trolley from a straight section to a curved section (and vice versa) presents many design constraints that designers must confront. In fact, during the transition between these sections, the instantaneous change in the velocity vector direction during the transition leads to a discontinuity in acceleration, causing the conveyor trolley to deviate from the guide rail, which in turn causes the conveyor trolley to detach from the straight guide rail.

[0010] To overcome these drawbacks, the applicant designed and developed an improved conveying system, detailed in International Patent Application WO 2022 / 03745, which includes a conveying trolley movable along a fixed sliding track. This sliding track is equipped with multiple irregularly shaped guide rails that define a cam profile, on which corresponding rolling elements slide. The shape of the irregularly shaped guide rails, particularly the shape of the curved sections and / or the transition sections between straight and curved sections of the track, allows for overcoming the aforementioned drawbacks of the prior art.

[0011] However, in the conveying system described in WO 2022 / 03745, the relative arrangement between the rolling elements and the fixed sliding rails can only ensure the correct movement of the trolley within a limited load capacity. In fact, excessive weight of the conveyed object and / or its asymmetrical arrangement relative to the trolley's center of gravity can cause the rolling elements to unexpectedly disengage from the sliding rails, especially when the trolley is traveling on curved sections and / or transition sections.

[0012] This is obviously a disadvantage because it imposes limitations on the nature, weight, and overall size of the objects that need to be transported, as the system can only safely transport small, lightweight objects. Summary of the Invention

[0013] Therefore, it is necessary to improve the conveying system so as to overcome at least one of the shortcomings of the existing technology.

[0014] In particular, an object of the present invention is to provide a conveying system that is reliable during use to ensure that the system can operate correctly, especially when the conveying trolley transitions from a straight section to a curved section and vice versa.

[0015] Another object of the present invention is to provide a conveying system in which each conveying trolley has a greater load capacity than conveying trolleys known in the prior art, so as to be able to move heavier and larger objects than conveying trolleys known in the prior art can transport.

[0016] Another object of the present invention is to provide a conveying system in which an object can be held stably arranged on a conveying trolley, especially along curved segments and / or in transitions between straight segments and curved segments.

[0017] Another object of the present invention is to provide a conveying system in which the anchoring of the conveying trolley to the sliding track is firm and durable, and the coupling gap between the rolling element and the guide rail remains constant in any segment of the trolley traveling along the path, especially in the transition segment between straight and curved segments.

[0018] The applicant has designed, tested and implemented the present invention to overcome the shortcomings of the prior art and to obtain these and other objectives and advantages.

[0019] The invention is set forth and characterized in the independent claims. The dependent claims describe other features or variations of the main inventive concept of the invention.

[0020] In accordance with the above objectives, a conveying system for conveying objects is provided, which overcomes the limitations of the prior art and eliminates the defects existing in the prior art.

[0021] According to one aspect of the invention, the conveying system comprises: - Sliding tracks, which have inner and outer sides that are opposite to each other and spaced apart; - A moving unit capable of moving along a sliding path on the sliding rail, the sliding path having at least a curved path portion and at least a straight path portion; - A driving device configured to move the moving unit on the sliding track.

[0022] The sliding track includes: - An inner rolling guide located inside the sliding track, wherein the inner rolling guide has at least one inner straight portion, at least one inner curved portion, and an inner transition portion between the inner straight portion and the inner curved portion, and wherein the inner rolling guide includes first and second cams, which respectively have an inner upper rolling surface and an adjacent inner lower rolling surface. - An outer rolling guide located outside the sliding track, wherein the outer rolling guide has at least one outer straight portion, at least one outer curved portion, and an outer transition portion between the outer straight portion and the outer curved portion, and wherein the outer rolling guide includes a third and a fourth cam, which respectively have an outer upper rolling surface and an adjacent outer lower rolling surface. The inner upper rolling surface and the outer upper rolling surface are parallel to each other along the entire sliding path, while the inner lower rolling surface and the outer lower rolling surface are parallel to each other along the entire sliding path.

[0023] The mobile unit includes: - At least one inner rolling unit configured to engage with the inner rolling guide, and comprising first and second rolling elements configured to roll on the upper inner rolling surface and the lower inner rolling surface, respectively, the first and second rolling elements rotating about first and second rolling axes that are parallel to each other. - An outer rolling unit configured to engage with the outer rolling guide includes third and fourth rolling elements, which are respectively configured to roll on the outer upper rolling surface and the outer lower rolling surface, and the third and fourth rolling elements rotate about third and fourth rolling axes that are parallel to each other and spaced apart.

[0024] According to one aspect of the invention, the first and third rolling elements are arranged opposite to each other, and the second and fourth rolling elements are arranged opposite to each other.

[0025] According to another aspect of the invention, on the inner and outer transition portions, the upper rolling surfaces (the inner upper rolling surface and the outer upper rolling surface, respectively) follow a different profile than the lower rolling surfaces (the inner lower rolling surface and the outer lower rolling surface, respectively), so as to define a varying outer cam profile deviation between the outer upper rolling surface and the outer lower rolling surface along the outer transition portion, and a varying inner cam profile deviation between the inner upper rolling surface and the inner lower rolling surface along the inner transition portion, such that during movement along the sliding track, all four rolling elements are simultaneously kept in contact with the inner and outer transition portions.

[0026] According to one aspect of the invention, the distance between the inner upper rolling surface and the outer upper rolling surface, and the distance between the inner lower rolling surface and the outer lower rolling surface, remain constant along the inner and outer transition portions, respectively; the distances are measured perpendicular to a plane that is tangent to the rolling surfaces point by point.

[0027] The advantage of the conveying system according to the invention is that it eliminates the design limitations that significantly restrict the load-bearing capacity of the moving unit in the prior art, thereby enabling the conveying of larger and heavier objects than known solutions in the prior art. A conveying system is provided in which the anchoring of the conveying trolley to the sliding track is firm and durable, and the coupling gap between its rolling elements and the guide rail remains constant in any segment of the trolley traveling along the path, especially in the transition between straight and curved segments.

[0028] On the one hand, this is due to the presence of deviations in the inner and outer cam profiles, which are variable at the transitions. This allows the moving unit to be arranged relative to the sliding track in a way that does not detach from the track itself, because the profile of the rolling surface can compensate for the different point-by-point curvatures of the moving unit at these transitions. On the other hand, this is due to the fact that the rolling element constrains the moving unit to maintain contact with both the inner and outer sides of the sliding track.

[0029] Therefore, the moving unit is constrained on the sliding track both inside and outside.

[0030] Compared to known solutions in the prior art (such as those described in WO 2022 / 03745, where the moving unit is constrained to the track only on one side (specifically the outer side), this makes the anchoring to the track more stable. This configuration of the moving unit allows for a more balanced force distribution, which does not lead to dynamic imbalances during the movement of the moving unit along the sliding track. Attached Figure Description

[0031] These and other aspects, features, and advantages of the invention will become apparent from the following description of embodiments given as non-limiting examples with reference to the accompanying drawings, in which: - Figure 1 This is a simplified perspective view of a conveying system according to the teachings of the present invention; - Figure 2 yes Figure 1 A simplified schematic top view of an enlarged portion of the conveyor system; - Figure 3 It is along Figure 4 A schematic cross-sectional view of the trajectory line III-III in the diagram; - Figure 4 , Figure 5 and Figure 6 They are along Figure 2 A simplified schematic cross-sectional view of the IV-IV, VV, and VI-VI trajectory lines; - Figure 7 and Figure 8 yes Figure 1 A schematic simplified enlarged top view of the moving unit included in the conveying system, showing it traveling along the transition between a straight segment and a curved segment; - Figure 9 The Cartesian coordinate graph shows the trend of cam profile deviation along the sliding path.

[0032] For ease of understanding, the same reference numerals are used as much as possible to identify the same common elements in the figures. It should be understood that elements and features of one embodiment can be readily combined or incorporated into other embodiments without further explanation. Detailed Implementation

[0033] We will now describe in detail feasible embodiments of the invention, one or more examples of which have been illustrated in the accompanying drawings by way of non-limiting illustration. The wording and terminology used herein are also for the purpose of providing non-limiting examples.

[0034] refer to Figure 1 This describes a conveying system for transporting objects, generally indicated by reference numeral 10.

[0035] Objects not shown in the accompanying drawings may be, for example, products to be assembled, particularly products in automated production lines in the packaging industry. It is quite evident that the conveying system according to the invention is suitable for conveying various types of objects, and the type, shape, and size of the objects do not affect the scope of protection of this invention.

[0036] The conveying system 10 includes a fixed sliding track 11 extending along a continuous, uninterrupted sliding path.

[0037] The conveying system 10 also includes a guide rail base 33, the shape of which can follow the shape of the fixed sliding track 11, and the guide rail base 33 is arranged below the sliding track 11.

[0038] exist Figure 1 In the visible example, the sliding track 11 has a long and narrow shape, is basically inscribed within a rectangle, and includes two straight sections and two curved sections connected to each other in an alternating order.

[0039] It is important to note that Figure 1 The sliding path indicated by the marker A can be closed, such as... Figure 1 The situation shown and described here is either open or open. Clearly, the shape of the sliding track 11 defines the contour of the sliding path A.

[0040] The conveying system 10 includes a moving unit or trolley capable of moving along the sliding track 11, indicated by reference numeral 12.

[0041] As will become clear below, the relative arrangement between the moving trolley 12 and the sliding track 11 changes point by point, especially in certain sections of the sliding path A. For this reason, the sliding path A is defined as the trajectory followed by the geometric center of the moving trolley 12.

[0042] In some variations of the conveying system 10, multiple mobile trolleys 12 are provided, all of which slide on the sliding track 11 in a coordinated manner.

[0043] The mobile trolley includes a resting surface 32 for objects; for clarity, in... Figures 1 to 3 and Figures 5 to 8 It has been removed from the website, only in [the context of the website]. Figure 4 The diagram is schematically shown. The resting plane 32 is substantially horizontal and centered relative to the sliding track 11. Preferably, the trajectory of its plane of symmetry Y passes through the sliding track 11 below.

[0044] The mobile trolley 12 moves along the sliding track 11 between two or more operating stations (not shown) arranged along the sliding path A. Preferably, the mobile trolley 12 can move bidirectionally along the sliding track 11, such as... Figure 1 As shown by arrow F in the diagram.

[0045] The mobile trolley 12 includes an upper wall 12a, which is oriented horizontally and adjacent to the sliding track 11, located directly below the sliding track 11. The mobile trolley 12 also includes a lower wall 12b, which is parallel to the upper wall 12a and connected to the upper wall 12a via a connecting wall 12c, which is arranged perpendicular to the upper wall 12a and the lower wall 12b, and is particularly vertical.

[0046] In the example given here, the trolley 12 is shaped like a "C", and the guide rail base 33 is at least partially received in the recess of the "C", as shown. Figure 4 The cross-sectional view is shown.

[0047] The mobile trolley 12 moves along the sliding track 11 via a drive mechanism.

[0048] In particular Figure 1 and Figure 4 In the embodiment shown, the conveying system 10 includes a linear motor 13, which includes a primary winding 13a that interacts with a permanent magnet 13b to determine the movement of the trolley 12 on the sliding track 11 by appropriately controlling the defined electromagnetic field between them.

[0049] In particular, the linear motor 13 includes a plurality of primary windings 13a preferably evenly distributed along the guide rail base 33. Specifically, the primary windings 13a are arranged both on the upper surface 34 of the guide rail base 33, facing the upper wall 12a, and on the lower surface 35 of the guide rail base 33, facing the lower wall 12b, as shown below. Figure 4 The cross-sectional view is shown.

[0050] Furthermore, the linear motor 13 includes at least one permanent magnet 13b, which is operatively associated with the mobile carriage 12, particularly housed within a suitable mounting bracket obtained within the carriage. Preferably, the shape of this mounting bracket matches the shape of the permanent magnet 13b. In the example given here, two permanent magnets 13b are associated with each mobile carriage 12, one disposed below its upper wall 12a and the other disposed above its lower wall 12b.

[0051] In any case, the movement of the mobile carriage 12 is achieved by sequentially and selectively activating the primary winding 13a in a manner well-known in the art. The resulting electromagnetic field determines the movement of the mobile carriage 12 by interacting with the electromagnetic field of the permanent magnet 13b on the carriage.

[0052] Although we will only mention the use of linear motors below, the description can also be applied to other types of conveying systems, such as indexing chain or belt conveyors, in which the moving trolley moves in a stepping motion.

[0053] The conveying system 10 includes an inner rolling guide rail 16 and an outer rolling guide rail 17 that extend along the sliding path A, and are configured to allow the trolley 12 to move on the sliding track 11.

[0054] The inner rolling guide 16 is arranged on the inner side 30 of the sliding track 11, while the outer rolling guide 17 is arranged on the outer side 31 of the sliding track 11.

[0055] In the given example, the sliding track 11 has a closed profile.

[0056] Each moving trolley 12 includes a first rolling unit 18 and a second rolling unit 19, which respectively cooperate with the inner rolling guide 16 and the outer rolling guide 17 in a manner that will be described in detail below.

[0057] Each inner and outer rolling guide 16, 17 includes a corresponding inner and outer straight portion (denoted by reference numerals 16a, 17a) and a corresponding inner and outer curved portion (denoted by reference numerals 16b, 17b).

[0058] The transition from the corresponding straight sections 16a and 17a to the corresponding curved sections 16b and 17b occurs at the corresponding transition sections, indicated by reference numerals 16c and 17c. Figures 1 to 3 (hereinafter also referred to as "inner transition 16c" and "outer transition 17c").

[0059] In addition, each inner and outer rolling guide 16, 17 includes a pair of cams, each cam defining a corresponding rolling surface.

[0060] For clarity of disclosure only, in the following text, we will refer to the pair of cams included in the inner rolling guide 16 as "inner upper cam" and "inner lower cam", denoted by reference numerals 20 and 21, respectively; and the pair of cams included in the outer rolling guide 17 as "outer upper cam" and "outer lower cam", denoted by reference numerals 22 and 23, respectively. Each of these cams includes a corresponding rolling surface: the inner upper cam 20 includes an inner upper rolling surface 20a, the inner lower cam 21 includes an inner lower rolling surface 21a, the outer upper cam 22 includes an outer upper rolling surface 22a, and the outer lower cam 23 includes an outer lower rolling surface 23a.

[0061] Preferably, the inner upper cam 20 and the inner lower cam 21 are adjacent to each other.

[0062] Preferably, the outer upper cam 22 and the outer lower cam 23 are adjacent to each other. In the example shown here, the inner upper rolling surface 20a is opposite to and faces the outer upper rolling surface 22a, and the inner lower rolling surface 21a is opposite to and faces the outer lower rolling surface 23a.

[0063] The inner and outer rolling guides 16 and 17 are separated by a distance D, which is approximately equal to the width of the sliding track 11 measured along a line segment perpendicular to the inner side 30 and the outer side 31.

[0064] Specifically, distance D is the distance between the inner upper rolling surface 20a and the outer upper rolling surface 22a, which is measured along a line segment that is perpendicular to two planes that are tangent to these surfaces at the measurement points.

[0065] Similarly, the inner lower rolling surface 21a is also separated from the outer lower rolling surface 23a by the same distance D, which is measured along a line segment that is perpendicular point by point to two planes that are tangent to these surfaces at the measurement points.

[0066] The distance D is essentially constant along the entire sliding path A, whether measured between the upper cams 20 and 22 or between the lower cams 21 and 23.

[0067] The rolling surfaces 20a, 21a, 22a, and 23a of cams 20, 21, 22, and 23 are arranged at corresponding rolling heights relative to the sliding rail 11. These rolling heights are respectively denoted by numerical references H1, H2, H3, and H4 for the rolling surfaces 20a, 21a, 22a, and 23a (see especially). Figure 5 and Figure 6 ).

[0068] The rolling heights H1, H2, H3, and H4 are measured as distances from the corresponding fixed reference surfaces, such as... Figure 5 and Figure 6 As shown by the dashed line, the fixed reference surface defines a plane that passes through the central directrix located at the center of the sliding track 11, the distance of which is obtained along a line segment perpendicular to the fixed reference surface. For example, the fixed reference surface may correspond to the plane of symmetry Y and coincide with the trajectory defined by the sliding path A followed by the geometric center of the moving trolley 12.

[0069] In the example given here, the inner upper surface 20a and the outer upper surface 22a, which are parallel to each other along the entire sliding path A, have the same profile along the straight sections 16a, 17a and along the curved sections 16b, 17b, and are therefore arranged at the same rolling heights H1, H3 in these sections.

[0070] The inner lower surface 21a and the outer lower surface 23a, which are parallel to each other along the entire sliding path A, have the same profile along the straight sections 16a and 17a and along the curved sections 16b and 17b, and are therefore arranged at the same rolling heights H2 and H4 in these sections.

[0071] In some embodiments, in the inner and outer transition portions 16c, 17c, the first rolling height H1 of the inner upper rolling surface 20a can be approximately equal to the fourth rolling height H4 of the outer lower rolling surface 23a, and the second rolling height H2 of the inner lower rolling surface 21a can be approximately equal to the third rolling height H3 of the outer upper rolling surface 23a.

[0072] In particular, the difference between the absolute values ​​of the first and second rolling heights H1 and H2 measured at the same point on the sliding path defines the inner cam profile deviation Si. Figure 5 and Figure 6 You can see it better in the enlarged image.

[0073] In a completely similar manner, the difference in the absolute values ​​of the third and fourth rolling heights H3 and H4, measured at the same point on the sliding path, also defines the outer cam profile deviation Se. Figure 5 and Figure 6 It can also be seen better in the enlarged image.

[0074] In this specification, whenever the inner cam profile deviation Si or the outer cam profile deviation Se is mentioned, it should be understood that the measurement refers to the height of the two cams of the inner rolling guide 16 or the outer rolling guide 17 taken at the same point.

[0075] The first and second rolling heights H1 and H2, and the third and fourth rolling heights H3 and H4 are arranged such that the value of the cam profile deviation S changes only when measured in the corresponding transition sections 16c and 17c, and in particular changes point by point.

[0076] Figure 5 The chart shows the trend of the inner cam profile deviation Si or the outer cam profile deviation Se. It can be clearly seen that this parameter only presents a non-zero value in the transition parts 16c and 17c.

[0077] In the example given here, the value of the inner cam profile deviation Si is greater than the value of the outer cam profile deviation Se, for example, about twice as much, at least for a portion of the transitions 16c, 17c.

[0078] For comparison Figure 2 and Figure 5 and Figure 3 and Figure 6 As can be seen in the example shown by the inner and outer transition sections 16c and 17c that the moving trolley 12 will first encounter ( Figure 2 and Figure 3 (at the top of the middle), when viewed from above, the inner and outer upper cams 20 and 22 have essentially the same profile ( Figure 2 ), and in Figure 3In the cross-sectional view, the inner cam profile deviation Si (although less noticeable due to its small absolute value) and the outer cam profile deviation Se are more clearly visible; these two deviations are... Figure 5 The cross-sectional views are better visible. The inner and outer transition sections 16c and 17c, which the moving trolley 12 will encounter for the second time... Figure 2 and Figure 3 In the bottom of the image, the inner and outer upper cams 20 and 22 have configurations that make the top view (in the top view) Figure 2 In the figure, the inner cam profile deviation Si (although less noticeable due to its small absolute value) and the outer cam profile deviation Se are more clearly visible; these two deviations are in Figure 6 The cross-sectional views are all more clearly visible.

[0079] Therefore, the inner rolling surfaces (inner upper rolling surface 20a and inner lower rolling surface 21a, respectively) have different curve profiles at the inner transition portion 16c. Similarly, the outer rolling surfaces (outer upper rolling surface 22a and outer lower rolling surface 23a, respectively) also have different curve profiles at the outer transition portion 17c.

[0080] Each inner rolling surface (inner upper rolling surface 20a and inner lower rolling surface 21a, respectively) and each outer rolling surface (outer upper rolling surface 22a and outer lower rolling surface 23a, respectively) includes at least two corresponding inflection points along the corresponding inner and outer transition portions 16c and 17c. Figure 5 This is clearly visible in the chart. At these points, the concavity of the rolling surface changes.

[0081] At a qualitative level, for a section of transition 16c and 17c, the inner cam profile deviation Si or the outer cam profile deviation Se has a similar trend; in the remaining sections of the transition, the inner cam profile deviation Si or the outer cam profile deviation Se has a similar gradient to each other, although there is a spatial offset.

[0082] The first rolling unit 18 of the mobile trolley 12 includes first and second rolling elements 24 and 25, which are respectively configured to roll on the inner upper rolling surface 20a and the inner lower rolling surface 21a around the respective first and second rolling axes (denoted by reference numerals X1 and X2).

[0083] Similarly, the second rolling unit 19 of the mobile trolley 12 includes third and fourth rolling elements 26 and 27, which are respectively configured to roll on the outer upper rolling surface 22a and the outer lower rolling surface 23a around the respective third and fourth rolling axes (denoted by reference numerals X3 and X4).

[0084] Preferably, the first, second, third, and fourth rolling shafts X1, X2, X3, and X4 are parallel to each other, fixed, arranged substantially vertically, and perpendicular to the sliding path A.

[0085] In the illustrated embodiment, the first, second, third, and fourth rolling elements 24, 25, 26, and 27 are wheels capable of rotating about corresponding pins extending upward from the upper wall 12a, but it is quite obvious that they can be configured as any rolling element capable of rolling, such as, for example, wheels, rollers, or rolling elements of known types, or rolling elements to be developed in the future.

[0086] The widths of the corresponding rolling surfaces 20a, 21a, 22a, and 23a are sized and shaped according to the dimensions and shapes of the corresponding rolling elements 24, 25, 26, and 27 configured to roll on them.

[0087] The first and third rolling elements 24 and 26 are arranged at a higher vertical height (denoted by Q1 and Q3), which is higher than the lower vertical height (denoted by Q2 and Q4) where the second and fourth rolling elements 25 and 27 are located. Figures 4 to 6 All vertical heights, whether higher or lower, are measured from the reference plane containing the lower surfaces of the rolling elements 25 and 27. Figure 4 ).

[0088] Obviously, the upper rolling surfaces (inner upper rolling surface 20a and outer upper rolling surface 22a, respectively) on which the first and third rolling elements 24 and 26 roll are arranged at higher vertical heights Q1 and Q3.

[0089] Similarly, the lower rolling surfaces (inner lower rolling surface 21a and outer lower rolling surface 23a, respectively) on which the second and fourth rolling elements 25 and 27 roll are arranged at lower vertical heights Q2 and Q4.

[0090] Preferably, the higher vertical heights Q1 and Q3 and the lower vertical heights Q2 and Q4 are constant along the entire sliding path A.

[0091] Figure 7 and Figure 8 In the image, for clarity, the cam profile deviation has been exaggerated to show the interaction between the inner rolling unit 18 and the outer rolling unit 19 of the moving trolley 12 and the inner rolling guide rail 16 and the outer rolling guide rail 17, respectively.

[0092] The choice to use different cam profiles at the inner and outer transition sections is due to the fact that this creates two rails (upper rolling surface and lower rolling surface) with different profiles for the first and second rolling elements of the trolley. In particular, two rails are created on the inner side 30 and two rails are also created on the outer side 31.

[0093] In the inner transition section 16c (inner side 30) from the inner straight section 16a to the inner curved section 16b, the first rolling height H1 changes and is greater than the second rolling height H2 because the inner upper rolling surface 20a protrudes more than the inner lower rolling surface 21a protrudes more than the same reference surface, while the inner lower rolling surface 21a is concave inward, as shown by the dashed line. As mentioned earlier, the difference between the absolute values ​​of the two heights H1 and H2 determines the inner cam profile deviation Si, which varies locally in the first transition section 16c, i.e., changes point by point.

[0094] In the outer transition section 17c (second outer side 31) from the outer straight section 17a to the outer curved section 17b, the third rolling height H3 changes and is less than the fourth rolling height H4 because the outer upper rolling surface 22a protrudes less than the outer lower rolling surface 23a protrudes outward relative to the same reference surface, as shown by the dashed line. As mentioned earlier, the difference between the absolute values ​​of the two heights H3 and H4 determines the outer cam profile deviation Se, which varies locally in the second transition section 17c, i.e., changes point by point.

[0095] In other embodiments, i.e., in transition sections having configurations different from those shown, the relative arrangement of the inner and outer rolling surfaces can also be interchanged, as long as one rolling surface is more protruding than the other rolling surface, while the other rolling surface is more concave.

[0096] The rolling heights of the four surfaces at the same vertical height are related, which ensures that the sliding track always maintains a constant lateral width, which is equal to the distance D.

[0097] In particular, for the more prominent inner upper rolling surface 20a, there is a more concave inner lower rolling surface 21a (H1 is greater than H2), and there is also an outer upper rolling surface 22a that is more concave than the more prominent outer lower rolling surface 23a (H4 is greater than H3).

[0098] Alternatively, for the more concave inner upper rolling surface 20a, there is a corresponding more prominent inner lower rolling surface 21a (H2 is greater than H1), and there is also an outer upper rolling surface 22a that is more prominent than the more prominent outer lower rolling surface 23a (H3 is greater than H4).

[0099] It should be noted that, according to the conveying system 10 of the present invention, the inner cam profile deviation Si between the inner upper and inner lower rolling surfaces 20a and 21a of the first and second cams 20 and 21 is constant in the inner straight section 16a and the inner curved section 16b. Similarly, in the outer straight section 17a and the outer curved section 17b, the outer cam profile deviation Se is also constant between the upper and lower rolling surfaces 22a and 23a of the third and fourth cams 22 and 23. In other words, the first and second cams 20 and 21, and the third and fourth cams 22 and 23 are configured and arranged such that the first and second rolling heights H1 and H2, and the aforementioned third and fourth rolling heights H3 and H4 are constant along the inner and outer straight sections 16a and 17a and the inner and outer curved sections 16b and 17b, respectively.

[0100] Thus, the inner cam profile deviation Si and the outer cam profile deviation Se are constant in the inner and outer straight sections 16a and 17a and the inner and outer curved sections 16b and 17b, while at least one of the first and second rolling heights H1 and H2, and at least one of the corresponding third and fourth rolling heights H3 and H4, have variable values ​​along the corresponding inner and outer transition sections 16c and 17c, making the inner cam profile deviation Si and the outer cam profile deviation Se also variable along these transition sections 16c and 17c, such as... Figure 5 As shown in the chart.

[0101] According to a specific embodiment, in the inner and outer straight portions 16a and 17a and the inner and outer curved portions 16b and 17b of the rolling guides 16 and 17, the rolling heights H1, H2, H3 and H4 of the rolling surfaces 20a, 21a, 22a and 23a are the same.

[0102] The geometric arrangement of rolling elements 24, 25, 26, and 27 means that the center distance I between the pair of rolling elements 24 and 25 included in the inner rolling unit 18 is ( Figure 2 , Figure 7 and Figure 8 The distance between the centers of the pair of rolling elements 26 and 27 contained in the outer rolling unit 19 is equal to I, such as Figure 2 As shown. These center distances are defined as the distances between the rolling axes X1-X2 and X3-X4 of the rolling elements 24-25 and 26-27.

[0103] The values ​​of the inner cam profile deviation Si and the outer cam profile deviation Se in the transition sections 16c and 17c are proportional to the center distance I. Therefore, as the center distance I increases, the cam profile deviation S will be larger, and the length of the transition sections 16c and 17c will also be longer.

[0104] Advantageously, the conveying system 10 according to the invention allows for the arrangement of rolling elements 24, 25, 26, and 27 such that the defined center distance I can reach a desired value, typically two or three times the center distance typical of this type of trolley known in the art, while maintaining a constant radius of curvature of the sliding path. Furthermore, the conveying system 10 according to the invention allows for ensuring that the anchorage of the moving trolley 12 to the sliding track 11 is firm and durable, and that the coupling gap between the rolling elements 24, 25, 26, and 27 and the inner and outer guide rails 16, 17 remains constant at any point along the path (particularly in the inner and outer transition sections 16c and 17c).

[0105] It should be noted that the different configurations of the lower and upper rolling surfaces, and the different rolling heights of the rolling surfaces (whether on the inner side 30 or the outer side 31), determine the inner cam profile deviation Si and the outer cam profile deviation Se, because these deviations vary point by point along the inner and outer transitions 16c, 17c, thus defining the variable travel angle of the moving trolley 12.

[0106] According to some embodiments, the conveying system 10 according to the invention may also include at least one position sensor, such as an encoder (not shown), which is configured to cooperate with the sliding rail 11 to determine the position of the moving trolley 12.

[0107] According to some variations, the conveying system 10 provides that the rolling heights H1 and H2, as well as H3 and H4, are different from each other in the inner and outer straight sections 16a, 17a and in the inner and outer curved sections 16b, 17b. In this case, to ensure the correct sliding of the moving trolley 12, the different rolling elements 24, 25, 26, and 27 can have different diameters, which are adapted to be related to the contours of the corresponding rolling surfaces 20a, 21a, 22a, and 23a on which they roll. Alternatively, or in combination with these variations, the different rolling elements 24, 25, 26, and 27 can have the same diameter, but the corresponding rolling shafts X1, X2, X3, and X4 are respectively arranged at appropriate distances from the sliding track 11, which are related to the contours of the rolling surfaces 20a, 21a, 22a, and 23a on which the rolling elements 24, 25, 26, and 27 roll.

[0108] Obviously, modifications and / or additions can be made to the aforementioned conveying system 10 without departing from the scope and range of the invention as defined by the claims.

[0109] It is also evident that, although the invention has been described with reference to specific embodiments, those skilled in the art will certainly be able to implement many other equivalent forms of the conveying system, which possess the features described in the claims and are therefore within the scope of protection defined by the claims. In the following claims, the reference numerals and symbols enclosed in parentheses are solely for ease of reading the claims and should not be considered as limiting factors of the scope of protection defined thereby.

Claims

1. A conveying system (10) for conveying objects, comprising: - a sliding track (11) having an inner side (30) and an outer side (31) opposite and spaced from each other; - a mobile unit (12) movable on the sliding track (11) along a sliding path (A) having at least a curved path portion and at least a straight path portion; - drive means configured to move the mobile unit (12) on the sliding track (11); wherein the sliding track (11) comprises: - an inner rolling guide (16) located at the inner side (30) of the sliding track (11), wherein the inner rolling guide (16) has at least one inner straight portion (16a), at least one inner curved portion (16b) and an inner transition portion (16c) interposed between the inner straight portion (16a) and the inner curved portion (16b), and wherein the inner rolling guide (16) comprises first and second cams (20, 21) having an inner upper rolling surface (20a) and an adjacent inner lower rolling surface (21a), respectively; and - an outer rolling guide (17) located at the outer side (31) of the sliding track (11), wherein the outer rolling guide (17) has at least one outer straight portion (17a), at least one outer curved portion (17b) and an outer transition portion (17c) interposed between the outer straight portion (17a) and the outer curved portion (17b), and wherein the outer rolling guide (17) comprises third and fourth cams (22, 23) having an outer upper rolling surface (22a) and an adjacent outer lower rolling surface (23a), respectively, the inner upper rolling surface (20a) and the outer upper rolling surface (22a) being parallel to each other along the entire sliding path (A) and the inner lower rolling surface (21a) and the outer lower rolling surface (23a) being parallel to each other along the entire sliding path (A); and the mobile unit (12) comprises: - at least one inner rolling unit (18) configured to engage with the inner rolling guide (16) and comprising first and second rolling elements (24, 25) configured to roll on the inner upper rolling surface (20a) and the inner lower rolling surface (21a), respectively, the first and second rolling elements (24, 25) rotating about first and second rolling axes (XI, X2) parallel and spaced from each other, respectively, - an outer rolling unit (19) configured to engage with the outer rolling guide (17) and comprising third and fourth rolling elements (26, 27) configured to roll on the outer upper rolling surface (22a) and the outer lower rolling surface (23a), respectively, the third and fourth rolling elements (26, 27) rotating about third and fourth rolling axes (X3, X4), respectively, wherein the first and third rolling elements (24, 26) are arranged opposite each other and the second and fourth rolling elements (25, 27) are arranged opposite each other, and wherein, on said inner transition (16c), said inner upper rolling surface (20a) follows a profile different from the profile followed by said inner lower rolling surface (21a), so as to define, along said inner transition (16c), a varying inner cam profile deviation (Si) between said inner upper rolling surface (20a) and said inner lower rolling surface (21a), characterized in that said third and fourth rolling axes (X3, X4) are parallel and spaced from each other, wherein, on said outer transition (17c), said outer upper rolling surface (22a) follows a profile different from the profile followed by said outer lower rolling surface (23a), so as to define, along said outer transition (17c), a varying outer cam profile deviation (Se) between said outer upper rolling surface (22a) and said outer lower rolling surface (23a), so that, during movement along said sliding path (11), while maintaining said first, second, third and fourth rolling elements (24-27) in contact with the respective inner and outer transitions (16c, 17c), and wherein the distance (D) between said inner upper rolling surface (20a) and said outer upper rolling surface (22a) and the distance (D) between said inner lower rolling surface (21a) and said outer lower rolling surface (23a) are constant and maintained constant along said inner and outer transitions (16c, 17c), respectively; said distances (D) being measured perpendicular to the plane tangent point by point to the rolling surfaces.

2. The system (10) according to claim 1, characterized in that said first, second, third and fourth rolling axes (X1, X2, X3, X4) are parallel to each other.

3. The system (10) according to claim 1 or 2, characterized in that said first, second, third and fourth rolling axes (X1, X2, X3, X4) are perpendicular to said sliding path (A).

4. The system (10) according to any of the preceding claims, characterized in that said first, second, third and fourth rolling axes (X1, X2, X3, X4) are fixed.

5. The system of any preceding claim, wherein, said inner upper rolling surface (20a) is opposite and facing said outer upper rolling surface (22a) and in that said inner lower rolling surface (21a) is opposite and facing said outer lower rolling surface (23a).

6. The system (10) according to any of the preceding claims, characterized in that each of said inner rolling surfaces, respectively inner upper and inner lower rolling surfaces (20a, 21a), and each of said outer rolling surfaces, respectively outer upper and outer lower rolling surfaces (22a, 23a), comprises two inflection points along the respective inner and outer transitions (16c, 17c).

7. The system (10) according to any of the preceding claims, characterized in that said drive means comprise a linear motor (13) comprising a primary winding (13a) arranged on a fixed wall (34) and at least one permanent magnet (13b) housed in said mobile unit (12) and configured to interact with said primary winding (13a).

8. The system (10) according to any of the preceding claims, characterized in that In said inner transition (16c), said inner upper and lower rolling surfaces (20a, 21a) are arranged at respective first and second rolling heights (H1, H2) with respect to said sliding rail (11), wherein the difference between the absolute values of said first and second rolling heights (H1, H2) measured at the same point of said inner transition (16c) defines said inner cam profile deviation (Si) having an instantaneously varying value, wherein said first and second rolling heights (H1, H2) are measured as distances from a fixed reference extending along a center line located in the center of said sliding rail (11), wherein said distances are measured along line segments perpendicular to said fixed reference.

9. The system (10) according to any of the preceding claims, characterized in that In said outer transition (17c), said outer upper and lower rolling surfaces (22a, 23a) are arranged at respective third and fourth rolling heights (H3, H4) with respect to said sliding rail (11), wherein the difference between the absolute values of said third and fourth rolling heights (H3, H4) measured at the same point of said outer transition (17c) defines said outer cam profile deviation (Se) having an instantaneously varying value, wherein said third and fourth rolling heights (H3, H4) are measured as distances from a fixed reference extending along a center line located in the center of said sliding rail (11), wherein said distances are measured along line segments perpendicular to said fixed reference.

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