Conveyor belt and method for closing a conveyor belt

Abstract

The invention relates to a conveyor belt (1) comprising first and second ends (1a; 1b) that define connectors having series of holes (5a). To close the conveyor belt, the connectors are arranged alternately, such that the series of holes (5a) are opposite each other in order to form a through-hole. A pin (6) is formed by a first portion (6a) and a second portion (6b) which each end in an annular stud. The two portions (6a, 6b) pass through the holes (5a) and meet in the same connector.

Description

CONVEYOR BELT AND METHOD FOR CLOSING A CONVEYOR BELT

[0001] The invention relates to a conveyor belt and to a method of closing a conveyor belt.

[0002] For the transport of products, it is known to use conveyors having a conveyor belt. The conveyor belt can be an openable belt, that is to say a belt whose two opposite ends are connected to define a ring as illustrated in document US2012 / 0217139. This document illustrates a closure system having a series of rings at each end. The two series of rings can be connected by a "U" shaped connector, each wing of which is inserted into one of the series of rings. The configuration of the closure system seems incompatible with use for the transport of foodstuffs which could become stuck in the closure system.

[0003] It is also known from document US 5,662,211 to connect the two ends of the conveyor belt by a simple rod which is inserted into a hole. The hole is defined by first staples formed at a first end of the conveyor belt and by second staples formed at the opposite end. The configuration allows significant pivoting of the first staples relative to the second staples which is detrimental to good control of bacterial proliferation during the transport of foodstuffs. In addition, the rod is made in two parts and is intended to be fixed integrally in the conveyor belt. The belt defines cavities allowing deformable arms arranged at the ends of the rod to move apart in the cavities to prevent unwanted exit of the parts of the rod.

[0004] To transport products, such as food, it is known to use conveyors equipped with belts. The belts are usually made of polymer material.

[0005] As illustrated in US 2009 / 0301845, the conveyor belt is in the form of an openable ring, i.e. the first end and the second end of the belt are separable. To open and close the belt, it is known to form series of clips at each end. The two series of clips are arranged alternately to close the belt and they define a series of holes at the first end and a series of holes at the second end. The two series of holes are mounted facing each other and a rod alternately passes through the holes of the first end and the second end. The rod prevents the two ends from separating. Depending on the configuration, the rod is mounted in a removable or non-removable manner.

[0006] The conveyor belt is driven by a drive wheel. The conveyor belt deforms to follow the curvature imposed by the drive wheel. Closing the conveyor belt with two sets of staples through which a securing rod passes results in the formation of a textured area with gaps that are conducive to the introduction of impurities and difficult to clean. In the food industry, it is particularly important that the conveyor belt is as neutral as possible with respect to the food it transports and in particular that it does not introduce bacterial contamination.

[0007] The use of a single through hole with a circular cross-section induces the formation of a pivot point between the two sets of clips, which deform differently and allow the introduction of food between the two clips, which is detrimental to the proper functioning of the conveyor. To reduce this phenomenon, it is proposed to use a through hole and a fixing rod that are not circular in cross-section. This configuration is difficult to implement and does not provide a satisfactory result.

[0008] From this same document, it is known to form a first end and a second end of the conveyor belt which define two series of holes which are intended to come opposite each other to close the conveyor belt. The two through holes are filled by two rods. The two holes are made inside two teeth which ensure the driving of the conveyor belt.

[0009] Here again, it appears that the observed operation is not optimal because the portion delimited by the two rods deforms differently from the rest of the conveyor belt, which makes the operation of the accessories, particularly the scrapers, more complicated. It also appears that the connection between the two ends of the openable belt is quickly contaminated by bacteria from food stuck in the closing area.

[0010] In one embodiment, several rods are introduced into the same through hole, which involves the formation of a very incomplete filling of the section of the through hole and therefore the formation of an empty zone which can store impurities.

[0011] In another embodiment, a rod is inserted into the through hole and then cut to fit the width of the conveyor belt. The matching of the rod length to the conveyor belt width is approximate so that the connection between the rod and the sidewall is a prime area for bacterial contamination.

[0012] It is also known to install the rod in the through hole and then melt the ends of the rod in order to make the rod unremovable. The shape of the fusion bead is not well controlled so that the fusion bead has an arbitrary shape with concavities that are difficult to clean and are not conducive to good management of bacterial contamination. Subject of the invention

[0013] An object of the invention consists in providing a conveyor belt which makes it possible to form a closure zone whose mechanical behavior is similar to the mechanical behavior outside the closure zone and whose bacterial contamination linked to the closure zone is better controlled than in the configuration of the prior art while allowing easy disassembly of the closure device to facilitate its possible cleaning.

[0014] This problem tends to be solved by means of a conveyor belt comprising:- a first end defining first staples with at least a first series of holes having a first diameter;- a second end defining second staples with at least a first series of holes having the first diameter, in a closed position of the conveyor belt, the first staples and the second staples form an alternation and the first series of holes are aligned to form a first through hole extending over an entire width of the conveyor belt;- a first rod passing through the first series of holes to secure the first end and the second end, the first rod being removable relative to the first end and the second end.

[0015] The closing device is remarkable in that the first rod is formed by means of a first part and a second part which each comprise an end-of-travel stop delimiting the maximum insertion of each of the first part and the second part into the first through hole.

[0016] Each end stop forms a knob defining a continuous annular contact area with a side face of one of the first and second clips around both ends of the first through hole. The first portion and the second portion meet within a single clip of the first clips and the second clips.

[0017] Advantageously, the first part defines with the second part an empty area inside said staple.

[0018] In a particular configuration, a thickness of the end stop is greater than the first diameter by at least 10% and less than an average thickness of the first clip and the second clip.

[0019] Preferably, the device for closing a conveyor belt comprises only a first rod. The clip receives the end of the first part and the end of the second part is located in a central third in a transverse direction.

[0020] According to one embodiment, the device for closing an openable conveyor belt comprises a first rod and a second rod offset in a longitudinal direction of the conveyor belt. The first rod and the second rod are each formed in two parts. The clip receiving the end of the first part and the end of the second part of the first rod is located in a first third in a transverse direction and is different from the clip receiving the end of the first part and the end of the second part of the second rod.

[0021] According to another embodiment, the device for closing an openable conveyor belt comprises a first rod and a second rod offset in a longitudinal direction of the conveyor belt. The first rod and the second rod are each formed in two parts. The end-of-travel stop of the first part of the first rod is monolithic with the end-of-travel stop of the first part of the second rod to form a stiffener whose thickness is greater than or equal to the average diameter of the first rod and the second rod and less than the thickness of the first clips and second clips at least between the first rod and the second rod.

[0022] The invention also relates to a conveyor belt which has a closing device whose bacterial contamination linked to the rod is better controlled than in the configuration of the prior art while allowing easy disassembly of the closing device to facilitate its possible cleaning.

[0023] This result is tended to be achieved by means of a conveyor belt having a closing device according to any of the preceding configurations.

[0024] The invention also relates to a method of closing a conveyor belt which is easier to use than the belts of the prior art and which allows better management of bacterial contamination.

[0025] This result is achieved by means of a method of closing a conveyor belt which comprises:- providing a conveyor belt provided with a first end defining first staples with at least a first series of holes having a first diameter and a second end defining second staples with at least a first series of holes having the first diameter,- closing the conveyor belt, the first staples and the second staples forming an alternation and the first series of holes being aligned to form a first through hole extending across an entire width of the conveyor belt;- introducing a first part of a first rod passing through the first series of holes to secure the first end and the second end, the first part of the first rod being removable with respect to the first end and the second end, the first part of the first rod terminating in a clip of the first clips and the second clips;- introducing a second part of the first rod passing through the first series of holes to secure the first end and the second end, the second part of the first rod being removable with respect to the first end and the second end, the second part of the first rod terminating in said clip of the first clips and the second clips.; Summary description of the drawings

[0026] Other advantages and characteristics will emerge more clearly from the following description of particular embodiments and implementations of the invention given as non-limiting examples and represented in the appended drawings, in which:

[0027] : schematically illustrates a perspective view of a conveyor equipped with a conveyor belt and a drive wheel;

[0028] : schematically illustrates a perspective view of a device for closing a conveyor belt according to the invention;

[0029] : schematically illustrates a longitudinal sectional view of a clip of a closing device, the conveyor belt being open;

[0030] : schematically illustrates a top view of an embodiment of a closing device in the closed position;

[0031] : schematically illustrates a side view of a closing device in the closed position;

[0032] : schematically illustrates a perspective view of one end of a conveyor belt with a series of clips;

[0033] : schematically illustrates a sectional view of an embodiment of a closing device in the closed position, the rods being made in two parts;

[0034] : schematically illustrates, in top view, two rods being inserted into the clips of the closing device;

[0035] : schematically illustrates a perspective view of a device for closing a conveyor belt deformed to follow the curvature of a wheel, the closing device being in the open position;

[0036] : schematically illustrates a perspective view of the internal face of one end of a conveyor belt;

[0037] : schematically illustrates a perspective view of a device for closing a conveyor belt deformed to follow the curvature of a wheel, the closing device being in the closed position, the rods being partially extracted;

[0038] : schematically illustrates a perspective view of the closing device in contact with a wheel;

[0039] : schematically illustrates a sectional view of the closing device with the rods pushed in, one rod being made in two parts;

[0040] : schematically illustrates a sectional view of the closing device with the rods pushed in, one rod being made in two parts, the rods being fitted with a blocker;

[0041] : schematically illustrates a perspective view of two rods connected by a stiffener;

[0042] : the, schematically illustrates a sectional view of a device for closing a conveyor belt rotating around a toothed wheel;

[0043] : the, schematically illustrates a perspective view of a closing device rotating around a toothed wheel and in contact with a scraper;

[0044] : schematically illustrates a perspective view of a closing device deformed to follow the curvature of a toothed wheel, the closing device being offset from the toothed wheel to illustrate the organization of the staples;

[0045] : schematically illustrates a side view of another embodiment of a device for closing a conveyor belt rotating around a toothed wheel and in contact with a scraper;

[0046] : schematically illustrates a perspective view of a closing device equipped with a single rod with an annular end-of-travel stop;

[0047] : schematically illustrates a perspective view of the closing device, the rod being partially extracted;

[0048] : schematically illustrates a sectional view of the closing device of the;

[0049] : schematically illustrates a sectional view of the closing device, the rod being made in two parts which join in the same clip;

[0050] : schematically illustrates a sectional view of the closing device, the rod being made in two parts which join in the same clip in the middle position along the width.;

[0051] Illustrates a conveyor provided with a conveyor belt 1 driven in movement by means of a drive device partially represented by a first wheel 2 which is a drive wheel and a second wheel 3 which can be a drive wheel or a follower wheel. The drive of the conveyor belt 1 by the first wheel 2 and possibly the second wheel 3 can be obtained by a plurality of teeth 4 which form transverse crosspieces. The teeth 4 extend mainly in a transverse direction YY which corresponds to the width of the conveyor belt 1. The drive wheel 2 is connected to a motor and is preferably a toothed wheel provided with teeth 2a. The teeth 4 of the conveyor belt 1 are repeated according to the repetition pitch P in the longitudinal direction XX.

[0052] The conveyor belt 1 is an openable conveyor belt provided with a closing device 5. Figures 1 and 2 illustrate a conveyor belt 1 in the closed state while illustrates a conveyor belt 1 in the open state.

[0053] As illustrated in Figures 1 to 25, the closing device 5 of the conveyor belt 1 comprises a first end 1a and a second end 1b. The first end 1a defines a plurality of first staples 1c and the second end 1b defines a plurality of second staples 1d. The first staples 1c protrude in the longitudinal direction XX, which forms an alternation between protruding areas and hollows as illustrated in the. The second staples 1d protrude in the longitudinal direction XX, which forms an alternation between protruding areas and hollows as illustrated in the.

[0054] To close the conveyor belt 1, the first staples 1c are inserted between the second staples 1d and vice versa. In the closed position of the conveyor belt 1, there is an alternation between the first staples 1c and the second staples 1d in the transverse direction YY as illustrated in Figures 4, 7 and 11 to 14. When the conveyor belt 1 is closed, the conveyor belt 1 defines a ring. The conveyor belt 1 has an inner face A and an outer face B which are opposite in the direction ZZ which defines the thickness. When the conveyor belt 1 is open, the first end 1a and the second end 1b are opposite in the longitudinal direction XX which is perpendicular to the transverse direction YY and perpendicular to the direction ZZ of the thickness.

[0055] As illustrated in Figures 3, 5, 6, 9, 10, 11, 13 and 14, the first clips 1c and the second clips 1d each define a first series of holes 5a and a second series of holes 5b. The holes of the first series of holes 5a are offset from the holes of the second series of holes 5b in the longitudinal direction XX. When the conveyor belt 1 is closed, the holes of the first series of holes 5a of the first end 1a and the second end 1b are aligned alternately behind each other in the transverse direction YY to form a first through hole that extends across the entire width of the conveyor belt 1.When the conveyor belt 1 is closed, the holes of the second series of holes 5b of the first end 1a and the second end 1b are aligned alternately behind each other in the transverse direction YY to form a second through hole which extends over the entire width of the conveyor belt 1. It is advantageous if the holes are of circular cross-section to facilitate insertion.

[0056] A first rod 6 is inserted into the first series of holes 5a to close the conveyor belt 1 and secure the first end 1a with the second end 1b. A second rod 7 is inserted into the second series of holes 5b to close the conveyor belt 1 and secure the two ends. The first rod 6 and the second pass through the first series of holes 5a and the second series of holes 5b to secure the two ends. The first rod 6 is offset from the second rod 7 in the longitudinal direction XX of the conveyor belt 1. When the conveyor belt 1 is open, the conveyor belt 1 is substantially rectangular in shape. The longitudinal direction XX is the direction of the largest dimension. The longitudinal direction XX is perpendicular to the transverse direction YY. The length is greater than the width which is greater than the thickness.The rods 6 and 7 extend over the entire width so as to form a connection between all the first staples 1c and the second staples 1d. Preferably, the first rod 6 and / or the second rod 7 are mounted to be removable relative to the first end 1a and the second end 2b.

[0057] Figures 1, 2, 4, 7, 8, 11, 12, 13, 14 and 16 to 25 illustrate a closing device 5 in a position closing the conveyor belt 1. The first clips 1c and the second clips 1d are arranged alternately in the transverse direction YY and the rods 6 and 7 pass alternately through the first clips 1c and the second clips 1d to fix the two ends together. Preferably, the first rod 6 has a circular section with a first diameter. It is also advantageous if the second rod 7 has a circular section with a second diameter. Even more advantageously, the first diameter is equal to the second diameter.

[0058] In order to form a closing device whose mechanical behavior in the closed position is closer to that of the rest of the conveyor belt, it is advantageous to provide a closing device which prevents the rotation of the first end 1a relative to the second end 1b. It is also advantageous to provide a simple configuration so as to facilitate the assembly and closing of the conveyor belt 1. It is also advantageous to seek a configuration which allows the use of first clips 1c and second clips 1d having simple shapes so as to facilitate the cleaning of the closing device 5.

[0059] To prevent rotation of the first end 1a relative to the second end 1b, it is advantageous to use a first rod 6 and a second rod 7 mounted in two separate holes offset in the longitudinal direction XX.

[0060] However, even if the use of two rods makes it possible to limit or even prevent the rotation of the clips of the closing device relative to each other, it is noted that the lack of rigidity linked to the very configuration of the closing device causes gaps to open during a complete rotation of the conveyor belt, which is conducive to the conservation of the material present on the closing device and which can induce bacterial proliferation. Against all expectations, it has been observed that the localized increase in the rigidity of the closing device makes it possible to reduce bacterial proliferation by limiting the appearance of gaps without making it too complicated to manage the passage of the closing device along wheels 2 and 3.

[0061] To locally increase the rigidity of the closing device 5 in the closed position without increasing the size, it is advantageous to have a separation distance D between the central axis of the first rod 6 and the central axis of the second rod 7 which is less than four times or three times the average diameter of the first rod 6 and the second rod 7. This makes it possible in particular to properly stiffen the area between the two rods. When the rod 6 / 7 has a circular section, the central axis corresponds to the center of the circle. When the section of the rod is other than a circle, the central axis follows the center of gravity of the different sections perpendicular to the YY direction. The average diameter corresponds to the sum of the first diameter and the second diameter, the whole is divided by two.

[0062] When the distance between the central axes of the first rod 6 and the second rod 7 becomes too great, a significant deflection of the closing device 5 is observed and the mechanical behavior of the closing device 5 is more difficult to manage when the closing device 5 circulates along a first wheel 2 or a second wheel 3.

[0063] As illustrated in, it is particularly advantageous for the separation distance D to be less than four times the average diameter of the first rod 6 and the second rod 7 and even more preferably less than three times the average diameter of the first rod 6 and the second rod 7 or even equal to twice the average diameter of the first rod 6 and the second rod 7.

[0064] Advantageously, the first staples 1c of the first end 1a and the second staples 1d of the second end 1b have a simple shape, for example a rectangular, square, semi-circular, semi-ovoid section. Preferably, the first staples 1c and the second staples 1d have an end in the direction XX with a convex shape, that is to say curved outwards. The use of a simple and preferably convex shape makes it easier to clean the staple. The use of a shape without concavity or without concavity with a small radius of curvature makes it easier to clean the closing device 5 and to prevent the proliferation of bacteria when the conveyor belt 1 transports foodstuffs.

[0065] It is particularly advantageous to have a first end 1a with first staples 1c that end in a circular arc connecting the inner face A and the outer face B. The second end 1b has a concave surface in the form of a circular arc whose shape is complementary to the end portion of the first staples 1c. The same is advantageously true for the second staples 1d and for the portions of the first end 1a that are opposite, that is to say between the opposite staples. The use of an arc of a circle of opposite polarity facilitates cleaning between the staples. The two complementary shapes facilitate cleaning. Preferably, the radius of curvature of the circular arc is smaller than the distance between the end wall of the staple defining the circular arc and the center of the nearest through hole.

[0066] Preferably, the first rod 6 is separated from the second rod 7 by a distance C less than twice the average diameter of the first rod 6 and the second rod 7, more preferably less than 1.5 times the average diameter of the first rod 6 and the second rod 7. Even more preferably, the first rod 6 is separated from the second rod 7 by a distance C greater than or equal to 0.5 times the average diameter of the first rod 6 and the second rod 7 and even more preferably greater than or equal to 0.75 times the average diameter of the first rod 6 and the second rod 7 or greater than one time the average diameter of the first rod 6 and the second rod 7. When the distance C is less than 0.5 times the average diameter, this can cause a reduction in mechanical performance.Unexpectedly, bringing the first rod 6 and the second rod 7 closer together results in an increase in mechanical rigidity without any obvious degradation in tear resistance. This configuration is more advantageous than a single thicker rod or two thicker and more distant rods.

[0067] In a particularly advantageous embodiment, the two rods 6 and 7 have a circular section with a diameter equal to a first value and the two rods 6 and 7 are separated by a distance equal to the first value.

[0068] The use of a rod or each rod having a circular section makes it easier to insert the rods into series of holes that have complementary shapes, i.e. holes with a circular section with a diameter substantially identical to that of the rods. The rods and holes having substantially identical sections, this makes it possible to effectively lock the first end with the second end, which brings the mechanical behavior between the fixing area and the rest of the conveyor belt closer.

[0069] By bringing the first rod 6 and the second rod 7 closer together and by adapting the ratio between the diameter of the rods and the thickness of the staples, it is possible to stiffen the closing device without significantly increasing the size of the closing device 5.

[0070] The use of two rods 6 and 7 offset in the XX direction to secure the staples makes it possible to limit or even prevent the rotation of the two staples relative to each other. However, this configuration does not prevent the presence of undesired mechanical behaviors at the ends of the staples. The aim is then to form a hard point between the two rods and advantageously slightly around the two rods so that the staples deform little during the rotation phases to avoid releasing areas that are difficult to access and therefore conducive to bacterial proliferation.

[0071] By using two rods that connect the two staples, rotation of the staples relative to each other is prevented. By increasing the thickness of the staples relative to the rest of the conveyor belt, it is possible to increase the rigidity of the closing device 5 in the closed position to approach or even exceed the rigidity of the rest of the conveyor belt.

[0072] The use of staples 1c and 1d that are thicker than the rest of the conveyor belt 1 makes it possible to stiffen the closing device 5 to have a behavior closer to the rest of the conveyor belt 1. By using staples 1c and 1d whose thickness is less than or equal to twice the thickness of the rest of the conveyor belt 1 in association with close-set rods 6 and 7, it is possible to form a closing device 5 that has a mechanical behavior close to or identical to that of the rest of the conveyor belt 1. The doubling of the thickness between the staples 6 and 7 and the rest of the conveyor belt 1 can be managed by the equipment associated with the conveyor belt 1, for example a scraper 8 that is arranged to scrape the external face B. This technical solution is particularly advantageous because it is simple to implement while limiting the size of the closing device 5.

[0073] Advantageously, the average thickness of the first staples 1c and the thickness of the second staples 1d are each less than or equal to twice an average thickness of the conveyor belt 1 and at least 10% greater than the average thickness of the conveyor belt 1. The average thickness is calculated from one end to the other in the direction XX without taking into account the teeth 4 intended for driving the conveyor belt 1 where applicable.

[0074] It is preferable that the thicknesses of the first staples 1c and the second staples 1d are constant or substantially constant at least from one end of the first hole 5a to the opposite end of the second hole 5b. The ends correspond to the furthest opposite ends in the direction XX. More preferably, the thickness is equal and constant to twice the average thickness of the conveyor belt excluding the first and second staples.

[0075] In order to have a mechanical behavior of the closing device 5 which closes the conveyor belt 1 which is close to that of the rest of the conveyor belt, it is advantageous to limit the length of the staples. It is preferable that the first staples 1c and the second staples 1d extend over a distance less than or equal to five or six times the average diameter of the first rod 6 and the second rod 7 in a longitudinal direction XX of the conveyor belt 1. It is advantageous to have staples whose length is less than four times or three times the separation distance between the central axes of the rods 6 and 7, i.e. the distance D. It is also preferable that the staples have a length which is less than 10 times the average thickness of the staples, advantageously less than 5 times the average thickness of the staples.

[0076] The length is calculated as the dimension projecting from the lateral face in the direction XX, i.e. the overlap length between the first staples 1c and the second staples 1d. Such a limitation of the length of the staples makes it possible to use thin staples, for example staples whose average thickness is less than three times the thickness of the remainder of the conveyor belt 1, or even less than or equal to twice the thickness of the remainder of the conveyor belt 1. The staples have a thickness at least equal to the remainder of the conveyor belt 1, i.e. between the first end 1a and the second end 1b outside the closing device 5. The thickness is measured ignoring the teeth 4 where applicable.The surface area occupied by the closing device 5 relative to the conveyor belt 1 being small, the thickness of the remainder of the conveyor belt 1 can be approximated by the average thickness of the conveyor belt 1 (ignoring the teeth 4 where applicable).

[0077] To increase the rigidity of the measuring device 5, it is preferable that the increase in thickness of the staple extends beyond the overlap zone by a distance which is less than the overlap zone. It is preferable that the thickness increases continuously up to the start of the protruding portion in the XX direction and even more preferably without reaching the height of the through holes in the ZZ direction. The overlap zone is the overlap zone between the staples 1c and 1d in the YY direction.

[0078] By increasing the rigidity of the closure device 5, the forces applied to the rods are increased. In order not to overstress the rods that connect the staples in shear, it is advantageous to increase the width of the staples. It is preferable to have first staples and second staples that have a width greater than twice the average diameter of the first rod 6 and the second rod 7, preferably greater than 2.5 times or three times. The width is measured in the YY direction. With the use of a two-rod fastener, it is possible to increase the repetition pitch of the staples.

[0079] In order to provide a closure device 5 whose rigidity is closer to that of the rest of the conveyor belt, it is preferable to have first staples and second staples whose width is greater than twice the average thickness of the conveyor belt, more preferably greater than three times the average thickness of the conveyor belt.

[0080] More preferably, the width of the first staples and the second staples is greater than twice the average diameter of the first and second rods and greater than twice the average thickness of the conveyor belt to reduce the shear stresses on the rods 6 and 7.

[0081] Advantageously, the conveyor belt 1 is made of polymer material, preferably of a single material, for example polyurethane. It is particularly advantageous to form the closing device 5 monolithically with the rest of the conveyor belt 1 with the exception of the rods.

[0082] It is advantageous for the first rod 6 to be made of metal or a polymer material. When the first rod 6 is made of a polymer material, it is preferable for the first rod 6 to be made of the same material as that of the conveyor belt 1. It is also advantageous to choose a material which has a Young's modulus which is equal to or greater than that of the material forming the rest of the conveyor belt, preferably the staples. With such materials, it is possible to form rods which stiffen the closing device. The second rod 7 is preferably made of the same material as the first rod 6.

[0083] Preferably, the average thickness of the conveyor belt 1 between the first rod 6 and the second rod 7, i.e. the thickness of the first staples 1c and the second staples 1d, is less than three times the average diameter of the first rod 6 and the second rod 7. Preferably, the average thickness of the first staples and the second staples is between 1.5 times and 2.5 times the average diameter of the first rod 6 and the second rod 7, preferably equal to twice the average diameter of the first rod 6 and the second rod 7. Such a configuration makes it possible to have good stiffening of the closing device 5 without significantly increasing the size of the closing device 5. The average thickness is measured in the projecting part in the direction XX.

[0084] It is particularly advantageous for the average diameter of the rods 6 and 7 to be at least equal to half the average thickness of the conveyor belt 1 between the two ends and outside the closing device, more preferably at least equal to 0.75 times the average thickness or even greater than or equal to the thickness of the conveyor belt between the two ends and outside the closing device. It is advantageous for the thickness not to be greater than 1.25 times the average thickness of the conveyor belt 1 between the two ends and outside the closing device 5.

[0085] In an advantageous embodiment, the diameter of the first rod 6 and the diameter of the second rod 7 are greater than 0.5 times the average thickness of the conveyor belt 1 measured from one end to the other in the longitudinal direction XX of the conveyor belt 1 and from one end to the other in the transverse direction YY of the conveyor belt 1. Preferably, the diameter of the first rod 6 and the diameter of the second rod 7 are greater than 0.75 or 0.8 times the average thickness of the conveyor belt 1. The average thickness is measured without the teeth 4 where applicable. It is advantageous for the diameter of the rods 6 and 7 not to be too small so as not to weaken the rods.By using rods whose diameters are close to the average thickness of the conveyor belt, it is possible to form rods whose mechanical strength is compatible with the stresses undergone by the conveyor belt 1 without increasing the size of the closing device 5.

[0086] It is also advantageous for the diameter of the first rod 6 and the diameter of the second rod 7 to be less than 1.5 times the average thickness of the conveyor belt 1 measured from one end to the other in the longitudinal direction XX of the conveyor belt 1 and from one end to the other in the transverse direction YY of the conveyor belt 1. This makes it possible to avoid forming a closing device 5 that is too thick. When the closing device is too thick, this makes it more difficult to use the conveyor belt because the excess thickness modifies the behavior of the closing device 5 relative to the rest of the conveyor belt 1. This also complicates the drive mechanism of the conveyor belt and / or the use of a scraper 8 intended to scrape the external face B of the conveyor belt. Illustrates an embodiment with a scraper 8 that presses on the external face B of the conveyor belt 1.

[0087] Advantageously, the closing device 5 which serves to fix the first end 1a with the second end 1b represents an area whose average thickness is greater than or equal to the average thickness of the conveyor belt 1 outside the closing device 5 and ignoring the teeth 4 where applicable. The increase in thickness makes it possible to stiffen the area located between the two rods 6 and 7 in order to have a bending which is closer to that of the rest of the conveyor belt 1.

[0088] Preferably, the first staples 1c and the second staples 1d are thicker than the rest of the conveyor belt 1 with the exception of the teeth 4 where applicable. Preferably, the first staples 1c and the second staples 1d have the same average thickness and they are arranged to form a first zone whose external face is flat so as to facilitate cleaning of the closing device 5. The external face of the staples can be offset outwards in comparison with the external face B of the conveyor belt 1 outside the closing device 5. Preferably, the first staples 1c protrude from the internal face A of the conveyor belt 1.Such an embodiment is illustrated in Figures 3 and 5 which illustrate staples approximately twice as thick as the rest of the conveyor belt 1 and of which a part of the excess thickness is arranged projecting from the external face B and a part of the excess thickness is arranged projecting from the internal face A in comparison with the conveyor belt 1 outside the closing device 5. In the particular embodiment illustrated in, the thickness of the staples increases then decreases until reaching the arc-shaped termination. The thickness of the staple increases until reaching one end of the hole, then the thickness decreases until reaching the arc-shaped termination. The increase then the decrease in thickness is observed in the longitudinal direction XX from the zone of attachment of the staple with the central part of the conveyor belt to the termination of the staple.

[0089] The first staples 1c are fixedly mounted to the conveyor belt. The increase in thickness to form the first staples 1c makes it possible to stiffen the first end 1a. The same is advantageously true for the second staples 1d.

[0090] When the conveyor belt 1 is intended to engage a toothed drive wheel, it is advantageous for the first rod 6 and the second rod 7 to be arranged between two consecutive teeth 4. It is advantageous for the separation distance between the first rod 6 and the second rod 7 to be at least two times smaller than the repetition pitch P of the teeth 4, preferably at least three or at least four times smaller than the repetition pitch P of the teeth 4. Preferably, the closing device 5 is equidistant between the two closest teeth 4. Advantageously, the closing device 5 takes the place of a tooth 4. It is preferable for the equidistant point of the two closest teeth 4 to be located in the space between the first rod 6 and the second rod 7 in the direction ZZ.

[0091] The first rod 6 and / or the second rod 7 may extend continuously over the entire length of the through hole in the YY direction. It is advantageous for the first rod 6 and / or the second rod 7 to be flush with each of the side walls of the conveyor belt. It is preferable for the first rod 6 and / or the second rod 7 to project slightly beyond the side walls in the YY direction.

[0092] In an advantageous embodiment illustrated in , the first rod 6 is formed in two parts with a first part 6a which has an end-of-travel stop bearing on a first side of the conveyor belt 1 and a second part 6b which has an end-of-travel stop bearing on a second side of the conveyor belt 1. The first side and the second side are arranged on one side and the other of the conveyor belt 1 in the transverse direction YY, that is to say according to the lateral dimension. The use of a first rod 6 in two parts makes it easier to install the first rod 6. The end-of-travel stop delimits the maximum insertion of each of the first part 6a and the second part 6b into the first through hole.Preferably, each end stop 6c forms a button defining a continuous annular contact zone with a lateral face of one of the first and second clips 1c, 1d around the two ends of the first through hole. Advantageously, the thickness of the end stop 6c is greater than the first diameter by at least 10%.

[0093] In particular, the end of the first part 6a bears on the end of the second part 6b. Advantageously, the end of the first part 6a and the end of the second part 6b meet inside the same first clip 1c. In an advantageous embodiment illustrated in , the end of the first part and the end of the second part end inside the same clip, defining an empty space. These embodiments are advantageous because this makes it possible to have all the through holes completely closed and to ensure good mechanical strength.

[0094] The same is advantageously true for the second rod 7.

[0095] Preferably, when the first rod 6 and / or the second rod 7 are formed in two parts with a first part 6a, 7a which has an end-of-travel stop 6c, 7c bearing on a first lateral side of the conveyor belt 1 and a second part 6b, 7b which has an end-of-travel stop 6c, 7c bearing on a second lateral side of the conveyor belt 1. The first part 6a ends in one of the first clips 1c and the second part 6b ends in said one of the first clips 1c.

[0096] The adjustment of the depth of insertion of the first rod 6 inside the first series of holes 5a can be formed by an end-of-travel stop 6c illustrated in the with a closing device having a single rod. The end-of-travel stop 6c has a width which prevents it from entering the first series of holes 5a. It is advantageous for the end-of-travel stop 6c to bear continuously in an annular manner on the lateral face. Such a stop configuration makes it possible to reduce or even avoid the introduction of foodstuffs at the exit of the first series of holes 5a which opens into the lateral wall of the conveyor belt 1.

[0097] When the first rod 6 is formed in two parts 6a and 6b with each of the parts being terminated by an end-of-travel stop 6c and with each of the parts being terminated inside one of the staples, the first rod 6 makes it more difficult to block the foodstuffs along the first series of holes 5a. The same is advantageously true for the second rod 7 provided with a stop.

[0098] It is particularly advantageous to use a first rod 6 and a second rod 7 which are both made in two parts. It is also advantageous if the first clip 1c which receives the first part 6a and the second part 6b of the first rod 6 is arranged in a first half of the conveyor belt and if the first clip 1c or the second clip 1d which receives the first part 7a and the second part 7b of the second rod 6 is arranged in a second half of the conveyor belt 1. The first half and the second half are separated by a median longitudinal plane which is perpendicular to the transverse direction YY.

[0099] In an advantageous embodiment illustrated in figures 2, 4, 7, 8, 11 to 17, the first rod 6 is fixed to the second rod 7 by means of a stiffener 10. The stiffener 10 connects the first rod 6 to the second rod 7. The assembly formed by the first rod 6, the second rod 7 and the stiffener 10 preferably defines a monolithic element, that is to say, one that cannot be dismantled. The stiffener 10 has a thickness that is greater than the average diameter of the first rod 6 and the second rod 7. It is advantageous for the width of the stiffener 10 to be less than or equal to the thickness of the first staples 1c and the second staples 1d. The thickness of the stiffener 10 is measured along the direction ZZ which passes through the external face B and the internal face A.Even more advantageously, the thickness of the stiffener 10 is less than or equal to the thickness of the conveyor belt over the entire facing distance between the stiffener 10 and the conveyor belt in the YY direction. The stiffener 10 does not protrude from the plane formed by the external face B of the closing device, nor from the internal face A.

[0100] Preferably, the stiffener 10 is made of the same material as the first rod 6 and the second rod 7, of metal or of any material which has a Young's modulus which is greater than or equal to the material forming the closing device and preferably the staples.

[0101] The distance between the first rod 6 and the second rod 7 is less than the repetition pitch of the teeth 4. Preferably, the first rod 6 and the second rod 7 are arranged in a space between two consecutive teeth 4. This configuration is more advantageous than a configuration where the first rod 6 and the second rod 7 are separated by a tooth 4. Advantageously, the repetition pitch P of the teeth 4 is greater than or equal to three times the distance D between the central axes of the first rod 6 and the second rod 7, preferably greater than or equal to five times and even more preferably greater than or equal to ten times the distance D between the central axes of the first rod 6 and the second rod 7.

[0102] Even more preferably, the minimum distance between a tooth 4 and a rod 6 / 7 is greater than or equal to three times the distance D between the central axes of the first rod 6 and the second rod 7. Advantageously, the assembly formed by the first rod 6 and the second rod 7 is arranged equidistant from two teeth 4 in the direction XX. Preferably, the tooth 4 closest to the first staples 1c is separated from the first staples 1c by a distance greater than three times the average distance of the diameter of the first rod 6 and the second rod 7. This makes it easier to obtain a behavior of the closing device closer to that of the rest of the conveyor belt.

[0103] Preferably, the average thickness of the first staples 1c is equal to the thickness of the second staples 1d. More preferably, once the first end 1 is fixed to the second end 2, the fixing zone has a flat external surface. Advantageously, the thickness of the first staples 1c and second staples 1d decreases at least from one end of the first hole to the opposite end of the second hole in a longitudinal direction respectively starting from a central portion of the conveyor belt 1 and heading towards an end of the first staples 1c and the second staples 1d. The thickness is equal to twice the average thickness of the conveyor belt excluding the first and second staples.

[0104] In an advantageous embodiment, the first rod 6 has a blocker 9 which is an elastically deformable zone. The blocker 9 is arranged to project so as to increase the friction between the first rod 6 and at least one of a first clip 1c or a second clip 1d. Figures 7, 8, 11, 14 and 15 illustrate a first rod 6 and a second rod 7 which are each provided with a protrusion. The protrusion forms the blocker 9 which locally increases the section of the rod to make it more difficult to push in and especially to extract it. It is preferable to form the blocker 9 close to the end-of-travel stop to facilitate insertion of the rod over almost the entire length of the rod. Preferably, when the rod is installed, the blocker 9 is wedged in the clip closest to the end-of-travel stop or the complete clip closest to the end-of-travel stop.

[0105] It is particularly advantageous to form a conveyor belt 1 comprising a closing device 5 according to any one of the preceding configurations. It is also advantageous to form a conveyor using a conveyor belt 1 comprising a closing device 5 according to any one of the preceding configurations.

[0106] In addition to the problems related to the mechanical management of the closure device 5 configured to fix the first end 1 with the second end 2, it is preferable that the closure device 5 does not cause bacterial proliferation. It is common for material to remain stuck in the interstices of the closure device 5 and in particular in the rod 6 / 7 which fixes the first end 1 with the second end 2. This problem is all the more difficult to manage since the length of the rod 6 / 7 must be adapted to the width of the closure device 5. When the rod 6 / 7 is too short, the through hole forms a cavity whose bottom is formed by the rod 6 / 7 and which is capable of retaining material. This difficult-to-access material will cause a proliferation of bacteria.When the rod 6 / 7 is too long, it makes it more difficult to drive the conveyor belt 1 because the rod 6 / 7 can get caught in equipment arranged near the conveyor belt 1. There is therefore a need to improve the cleaning management of the closing device 5.

[0107] In order to achieve this result, it is particularly advantageous to provide a rod 6 / 7 which has an end formed by a larger cross-sectional area which forms a continuous annular contact surface around the first hole or the second hole intended to receive the rod 6 / 7. It is complicated to have a rod 6 / 7 whose cross-section is perfectly identical to the cross-section of the through hole. The installation of the rod 6 / 7 is more difficult because the available space is small. The spacing then allows the introduction of material between the rod 6 / 7 and the edge of the through hole. It is therefore particularly advantageous to have a rod end which forms a plug continuously in contact with the side wall of the conveyor belt 1. The plug prevents access to the through hole.

[0108] In one embodiment, the hole of the closure device 5 present in the first end 1a is not a through hole. It is advantageous to have a plug which forms an end-of-travel stop 6c so that the first rod 6 stops in the immediate vicinity of the bottom of the hole, inside the last staple.

[0109] In another embodiment, the at least one hole of the closure device 5 is a through hole, it is then advantageous for the first rod 6 to be formed in two parts 6a and 6b and for the two parts 6a and 6b to be provided with a plug which has a continuous annular contact with the side walls of the conveyor belt 1. A plug is then present at each of the ends of the first rod 6 to prevent the introduction of material between the first rod 6 and the side wall of the hole.

[0110] It is advantageous for the plug to have a thickness that is less than or equal to the thickness of the staples. The thickness is measured along a direction ZZ that intersects the outer face B and the inner face A of the conveyor belt 1. This makes it possible to avoid forming a preferred attachment zone projecting from the conveyor belt 1, for example a scraper 8.

[0111] According to the embodiments, the closing device 5 may have a single first rod 6 or several rods, preferably the first rod 6 and the second rod 7. When the closing device 5 has several rods, it is advantageous for each of the rods 6 / 7 to have at least one end-of-travel stop in the form of an annular plug extending continuously around the first hole opening onto the side wall of the closing device 5. Figures 20, 21, 22 and 23 illustrate an embodiment with a single rod. This embodiment is less efficient than that presented previously for forming a closing device whose mechanical behavior is closer to the mechanical behavior of the rest of the conveyor belt 1. However, such an embodiment provides better resistance to bacterial proliferation.

[0112] The annular plug 6c defines a continuous annular contact with the side wall of one of the staples, here a first staple 1c, so as to prevent the insertion and retention of impurities in the through hole or the joint between the rod and the through hole. The aim is to form a rod whose section is as complementary as possible to the section of the holes formed in the staples. However, with manufacturing hazards and wear, a slight gap may form. This gap is known to be a preferred area for bacterial growth because it is difficult to clean.

[0113] It is therefore advantageous to form an annular plug which is in contact with the side wall and which limits or even prevents access to the end of the through hole.

[0114] To limit bacterial proliferation, it is advantageous to use a rod formed in two parts, each of which is terminated by an annular plug. Thus, the two ends of the through hole are plugged by two plugs which rest on a staple. As indicated above, it is preferable that the two ends of the two parts of the rod join in the same staple. All the through holes are plugged by one or the other of the two parts of the rod, which limits or even prevents the insertion of impurities into the through holes of the staples. As illustrated, the shapes of the staples and the hollows are as complementary as possible to avoid the insertion of material between the staples. By using simple shapes and one or more removable rods, it becomes easy to open the conveyor belt and clean it.

[0115] When the closing device 5 has a first rod 6 and a second rod 7, it is advantageous for the plugs of two adjacent rods to belong to the same monolithic element which preferably forms a stiffener 10 as illustrated in figures 15, 21 and 22. Each of the two plugs forms an annular contact surface with the side wall of the first or last staple to prevent access to the through hole.

[0116] When the two internal ends of the first rod 6 are in the same staple, it is very difficult for material to be inserted between the two parts of the rod. To facilitate the assembly of the parts of the rod, it is advantageous to form a free space in the through hole of the staple which is less than 50% of the dimension of the staple in the YY direction, preferably less than 25%. Advantageously, each of the parts of the first rod 6 extends inside the staple over a distance at least equal to 10%, preferably at least equal to 20%, more preferably at least equal to 30% of the width of the staple. The greater the distance of insertion of each of the parts of the first rod, the lower the risk of detachment. This makes it possible to avoid forming a soft point or a soft zone.

[0117] Preferably, when the closing device has only a first rod 6, the clip receiving the end of the first part and the end of the second part is located in a central third in a transverse direction YY.

[0118] In a particular embodiment, the first rod 6 and the second rod 7 are each formed in two parts. It is particularly advantageous for the staple receiving the end of the first part and the end of the second part of the first rod 6 to be different from the staple receiving the end of the first part and the end of the second part of the second rod 7. The differentiation of the staples makes it possible to better distribute the stresses. It is preferable for the two staples receiving the ends of the first rod 6 and the second rod 7 to be spaced apart by at least 5%, preferably at least 10%, of the width of the closure device in the YY direction.In a particular embodiment, the clip receiving the end of the first part and the end of the second part of the first rod 6 is located in a first third along the transverse direction YY and the clip receiving the end of the first part and the end of the second part of the second rod 7 is located in a third third along the transverse direction YY.

[0119] Preferably, the stopper is mounted so that it cannot be removed from the rest of the stem.

[0120] In another embodiment, the rod or each part of the rod is provided with a blocker 9 which is configured to block the position of the rod in the transverse direction YY when the rod is subjected to a force in the transverse direction YY which is less than a threshold value. When inserting the rod into the hole, the rod is inserted with a force which is greater than the threshold value. When the conveyor belt 1 moves, the rods are subjected to forces, a part of which results in a force in the transverse direction YY. The use of the blocker 9 makes it possible to hold the rod in position when the conveyor belt 1 rotates.

[0121] In a particular embodiment, the closure device defines an indentation at each of its side walls in the YY direction. The indentation corresponds to a narrowing of the width of the terminal clip so that the cap is not mounted protruding relative to the rest of the conveyor belt in the YY direction.

Claims

An openable conveyor belt (1) for foodstuffs comprising:- a first end (1a) and a second end (1b) of a conveyor belt (1) respectively defining first clips (1c) and second clips (1d) arranged alternately in a closed position of the conveyor belt (1), the first clips (1c) and the second clips (1d) each defining a first series of holes (5a) and a second series of holes (5b), in the closed position of the conveyor belt (1), the first series of holes (5a) are aligned to form a first through hole extending over an entire width of the conveyor belt (1) and the second series of holes (5b) are aligned to form a second through hole extending over the entire width of the conveyor belt (1);- a first rod (6) passing through the first series of holes (5a) to secure the first end (1c) and the second end (1d), the first rod (6) having a first diameter and being removable relative to the first end (1a) and the second end (1b); - a second rod (7) passing through the second series of holes (5b) to secure the first end (1c) and the second end (1d), the second rod (7) having a second diameter and being removable relative to the first end (1a) and the second end (1b), the second rod (7) and the first rod (6) being offset in a longitudinal direction (XX) of the conveyor belt (1), the first clips (1c), the second clips (1d), the first rod (6) and the second rod (7) forming a closing device configured to close the conveyor belt (1);- possibly a series of teeth (4) arranged projecting from an internal face (A) and intended for driving the conveyor belt (1), the teeth (4) being spaced according to a repetition pitch (P); characterized in that the first staples (1c) and the second staples (1d) have an average thickness at least 10% greater and less than twice the average thickness of the conveyor belt outside the closing device, the average thickness being calculated without taking into account teeth (4) intended for driving the conveyor belt (1) where applicable;in that a separation distance (D) between a central axis of the first rod (6) and a central axis of the second rod (7) is less than three times the average diameter of the first rod (6) and the second rod (7) to locally stiffen an area disposed between the first rod (6) and the second rod (7), the first rod (6) being spaced from the second rod (7) by a distance less than twice the average diameter of the first rod (6) and the second rod (7);in that each of the first rod (6) and the second rod (7) is formed by means of a first part (6a) and a second part (6b) which each comprise an end-of-travel stop (7c) delimiting the maximum penetration of each of the first part (6a, 7a) and the second part (6b 7b) into the first through hole and into the second through hole;in which each end-of-travel stop (6c, 7c) forms a knob protruding from a side wall of the conveyor belt (1);in that each button defines a continuous annular contact zone with a lateral face of one of the first and second clips (1c, 1d) around both ends of the first through hole and the second through hole; and in that the end-of-travel stop (6c) of the first part (6a) of the first rod (6) is monolithic with the end-of-travel stop (7c) of the first part (7a) of the second rod (7) to form a stiffener (10) whose thickness is greater than or equal to the average diameter of the first rod (6) and the second rod (7) and less than the thickness of the first clips (1c) and second clips (1d) at least between the first rod (6) and the second rod (7);in that, when the conveyor belt (1) has teeth (4), the first rod (6) and the second rod (7) are arranged between two consecutive teeth (4) and the separation distance between the first rod (6) and the second rod (7) is at least twice less than the repetition pitch (P).; Conveyor belt according to claim 1, wherein the first staples (1c) and the second staples (1d) are terminated by an arcuate portion and wherein the second end (1b) and the first end (1a) define a complementary shape intended to receive the arcuate portion between second staples (1d) and between the first staples (1c), the arcuate shape being observed according to a direction of insertion of the first rod (6) and the second rod (7). Conveyor belt according to claim 2, wherein the first staples (1c) and the second staples (1d) extend over a distance less than or equal to four times the separation distance (D) in a longitudinal direction (XX) of the conveyor belt (1). Conveyor belt according to claim 3, wherein the width of the first staples (1c) is greater than 2.5 times the average diameter of the first rod (6) and the second rod (7). Conveyor belt according to one of claims 3 and 4 in which the thickness of the first staples (1c) and second staples (1d) decreases at least from one end of the first hole to the opposite end of the second hole in a longitudinal direction respectively starting from a central portion of the conveyor belt (1) and heading towards an end of the first staples (1c) and the second staples (1d) and in which the thickness is equal to twice the average thickness of the conveyor belt excluding the first and second staples. An openable conveyor belt according to any one of claims 1 to 5, wherein an inner face (A) of the conveyor belt (1) is provided with teeth (4) and a tooth (4) closest to the first staples (1c) is separated from the first staples (1c) by a distance greater than three times the average distance of the diameter of the first rod (6) and the second rod (7), the tooth (4) being intended to mesh with a toothed wheel (3) to drive the conveyor belt in rotation. Device for closing an openable conveyor belt according to one of claims 1 and 2, in which the first part (6a) defines with the second part (6b) an empty zone inside said clip. Conveyor belt according to claim 1, Conveyor belt according to claim 2, wherein the first part (6a) defines with the second part (6b) a void area inside said staple. Conveyor belt according to one of claims 1 and 2, wherein a thickness of the end stop (6c) is greater than the first diameter by at least 10% and less than an average thickness of the first clip (1c) and the second clip (1d). Conveyor belt according to any one of claims 2 to 4, wherein the clip receiving the end of the first part (6a) and the end of the second part (6b) of the first rod (6) is located in a first third in a transverse direction (YY) is different from the clip receiving the end of the first part (7a) and the end of the second part (7b) of the second rod (7). An openable conveyor belt comprising a closing device according to any one of the preceding claims. A method of closing an openable conveyor belt comprising:- providing a conveyor belt (1) provided with a first end (1a) defining first staples (1c) with at least a first series of holes (5a) having a first diameter and a second end (1b) defining second staples (1d) with at least a first series of holes (5a) having the first diameter,- closing the conveyor belt (1), the first staples (1c) and the second staples (1d) forming an alternation and the first series of holes (5a) being aligned to form a first through hole extending across an entire width of the conveyor belt (1);- introducing a first part (6a) of a first rod (6) passing through the first series of holes (5a) to secure the first end (1a) and the second end (1b), the first part (6a) of the first rod (6) being removable with respect to the first end (1a) and the second end (1b), the first part (6a) of the first rod (6) ending in a clip of the first clips (1c) and the second clips (1d);- introducing a second part (6b) of the first rod (6) passing through the first series of holes (5a) to secure the first end (1a) and the second end (1b), the second part (6b) of the first rod (6) being removable with respect to the first end (1a) and the second end (1b), the second part (6b) of the first rod (6) ending in said clip of the first clips (1c) and the second clips (1d).;

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