Patent Publication Number: US-2023137570-A1

Title: Modular conveyor mat and module therefor

Description:
The invention relates to a module for a modular conveyor mat, and to a conveyor mat built up from modules. 
     Such modules and mats are generally known and are used for conveying products. 
     A module known from WO 2012074390 comprises a body part extending transversely to a conveying direction between two sides along a main axis, with a top for carrying products to be conveyed and a bottom for cooperation with a conveyor track. The body part is provided with coupling elements at the front and the rear as viewed in the conveying direction. The coupling elements at both front and rear comprise a series of successive hinge parts and adjacent receiving spaces alternating transversely to the conveying direction, and opposite coupling elements at the front and rear of the body part form a pair of a hinge part and a correspondingly formed receiving space, so that hinge parts and receiving spaces can interdigitate with receiving spaces and hinge parts of similar modules successive in conveying direction. Successive modules can be hingedly coupled with the aid of hinge pins extending transversely to the conveying direction, reaching through hinge bores provided in the hinge parts. In view of the force transmission between the modules, a relatively large number of relatively narrow coupling elements are provided. Thus, the number of points where the hinge pin is shear loaded is chosen to be as large as possible, and bending between these points is as small as possible. 
     Modules for modular conveyor mats are usually manufactured by means of molding, and are often manufactured from plastic material. Suitable plastic materials are, for example, polyester or acetal. The hinge pin is likewise preferably manufactured from plastic material, for example polypropylene or polyester. 
     Because they are molded, modules mutually have relatively small deviations regarding size, surface and shape. As a result, the modules can be properly assembled to form a mat. Modules successive in conveying direction can in this manner be joined to form a mat of a desired length. The mat is usually of endless design, so that it can be passed over a conveyor track with the aid of return wheels. The width of the mat may then be varied by placing a plurality of modules next to each other transversely to the conveying direction and coupling them by means of continuous hinge pins. 
     Rows of modules successive in conveying direction are often staggered with respect to each other transversely to the conveying direction, so that a brick pattern is formed with which continuous cracks in conveying direction between the modules of the mat can be avoided. To form the brick pattern, usually two sizes of modules are provided: long modules having along the main axis a normal length, for example 17 cm or 6″ and short modules having along the main axis a shorter length, for example 8.5 cm or 3″. In successive rows, long modules can be included in a manner staggered with respect to each other, and spaces having arisen at the longitudinal edge of the mat can then be filled up with a short module. 
     Modules located at longitudinal edges of the mat are designed as closing module by providing them with a lock provision for locking the hinge pin against migration transversely to the conveying direction. Such a locking provision may for instance be implemented as an integrally formed closing clip, but may also be implemented as a receiving provision for a loose closing clip or as a stop surface for an end face of a pin. 
     To build a mat, a large number of variants of modules may thus be necessary, for example a left and right long closing module, a left and right short closing module and a long central module without lock provision. In a number of cases, there may be added to these, for instance, a variant where modules located near the longitudinal edge or near the middle of the mat need to be provided further, at their undersides, with a guide element to cooperate with guide strips of the track on which the mat is supported. 
     Because of the relatively high costs of molds and the logistic complexity of a larger number of different modules, the modules are usually most preferably made only in as few variants as possible. For instance, long closing modules may be sawn to form short closing modules. The body part is then divided into a plurality of parts by dividing the body part along a dividing plane extending parallel to sides of the modules. 
     In WO2012074390 it has already been proposed to build a mat on the basis of just one type of module. With this module, all coupling elements are implemented with an equal width, and the body part is provided with a dividing plane which extends parallel to the sides, which is implemented as a break provision, and along which the module is divisible by breaking. Due to all coupling elements being made of equal width, the modules can be included in the mat on both a left and a right longitudinal edge, and be formed into a shorter closing module by breaking. However, a disadvantage of this module is that the locking provision, which is integrated into a hinge part bordering on a side of the module, is relatively weak. 
     The object of the invention is to provide a module for a modular conveyor mat and a conveyor mat built up from such modules, with which, while preserving the advantages mentioned, the disadvantages mentioned can be counteracted. 
     To that end, the invention provides a module for a modular conveyor mat, comprising a body part extending transversely to a conveying direction between two sides along a main axis, with a top for carrying products to be conveyed and a bottom for cooperation with a conveyor track, wherein the body part, at the front and rear as viewed in the conveying direction, is provided with coupling elements, wherein the coupling elements at both front and rear comprise a series of successive hinge parts and receiving spaces alternating transversely to the conveying direction, and wherein opposite coupling elements at the front and rear of the body part form a pair of a hinge part and a correspondingly formed receiving space, so that hinge parts and receiving spaces can interdigitate with receiving spaces and hinge parts of a similar module successive in conveying direction, and the successive modules are hingedly couplable with the aid of hinge pins extending transversely to the conveying direction, reaching through hinge bores provided in the hinge parts, wherein the body part is provided in the middle with a dividing plane which extends parallel to the sides and along which the module is divisible into two module halves, wherein the pairs of coupling elements located on the sides, viewed in the direction of the main axis, are implemented with a greater width than neighboring coupling elements of the body part, and wherein, further, pairs of coupling elements located on both sides of the dividing plane of the module are also implemented with the same width as the coupling elements with said greater width located on the sides. The merit of providing such a pattern of coupling elements of greater width is that, whilst preserving the advantages of the reduced number of types of modules, yet room can be made for accommodating a sufficiently strong locking provision. 
     The hinge parts of greater width on the side of the module can in the pattern lie diametrically with respect to each other with respect to both the opposite side of the body part and the side surface located on the same module half that borders on the dividing plane; this applies also to the receiving spaces. Both the modules and the module halves are 180° reversible about an axis transverse to the top, so that the front and rear can be interchanged for coupling with successive modules. Thus, the undivided module as well as both module halves after division can be easily applied in the conveyor mat. 
     At least a hinge part located on a side of the body part can, due to the widening, properly comprise a locking provision for locking the hinge pin against migration transverse to the conveying direction. The locking provision may be implemented as a blocking element which is adjustable between a release position and a blocking position and which in the release position leaves the bore of the hinge part clear (free), and in the blocking position extends into the bore and hinders passage of a hinge pin through the bore. 
     The locking provision may be an integrated locking provision, such as a closing clip adjustable between the positions mentioned, or a stop surface for axial cooperation with the end face of the hinge pin. The locking provision may also be implemented as a receiving provision for a detachable closing element, such as a closing clip which in the release position may, for instance, be detached, and in the blocking position may be mounted. A receiving provision has as an advantage that it can be applied on both sides of the module. 
     By choosing the width of the other coupling elements to be equal to that of the neighboring coupling elements mentioned, it can be achieved that the other coupling elements can be optimized for force transmission. The series of coupling elements between the wide coupling elements on the edge and those adjacent to the dividing plane can then have an equal width among themselves. 
     When the coupling elements that are implemented with a greater width have double the width of the other coupling elements, it can be achieved that the force transmission remains surprisingly good, while sufficient space is available for a locking provision. Within this context, double width is to be understood as a width in between 1.5 and 2.5 times the width of the neighboring coupling element, in particular between 1.8 and 2.2 times, more particularly 1.9 and 2.1 times and specifically 2 times. 
     When at least a hinge part located adjacent the dividing plane comprises two hinge part halves separated by a notch, the manufacturability of a wide hinge part can be improved. Especially, material can be saved, the cycle time can be kept short compared with a one-part solid hinge part, and creep and sagging of the surface can be counteracted. 
     By providing the body part with a guide element at the underside, in particular at the underside of only one of the module halves bordering on the dividing planes, it can be achieved that the module can cooperate with guide strips of the track on which the conveyor mat is supported. The guide element may be implemented, for example, as two mutually spaced-apart downwardly extending guide surfaces extending parallel to the side of the module. The guide element may be implemented as a separate part, which is for instance detachably coupled with the module. The guide element may also be formed integrally with the module, for example by including a detachable insert in the mold of the module. 
     By providing the body part at the bottom with a drive chamber, it can be achieved that the module can cooperate in a proper force transmission with teeth of a drive gear. The body part may for instance on either side of the dividing plane be provided with at least one drive chamber, so that both module halves have a drive chamber. Elegantly, the drive chamber extends in the longitudinal direction over the main axis along a plurality of coupling provisions, for example over a width of about three unwidened coupling elements. 
     By providing the body part with through openings extending between the top and bottom, it can be achieved that the module is liquid transmissive in a direction transverse to the top, for example for cleaning the conveyor mat and/or products to be conveyed thereon. 
     By providing at least a number of the receiving spaces near the body part with an overhang which, when a coupling element is received in the receiving space, forms an additional opening extending between the top and bottom, it can be achieved that an extra part of the conveying surface of the conveyor mat can be made of liquid-transmissive design. 
     The maximum dimension of the openings and additional openings in a conveying surface formed by tops of successive modules is, measured in the conveying surface, preferably about 2-5 mm, in particular about 3-4 mm. In this way, it can be achieved that the stability on the conveying surface is augmented of products having protrusions at the bottom. Advantageously, at least a percentage of about 20-60%, in particular about 50% of the conveying surface formed with the tops of the modules is open. By keeping the openings and additional openings towards the bottom substantially equal, cleanability can be enhanced. The sidewalls of the openings then run substantially parallel to counteract adherence of dirt. 
     By providing the body part with two main ribs extending along the main axis, each carrying hinge parts, and which are spaced apart with a mutual intermediate distance with respect to the main axis, a module can be formed that is relatively stiff, and relatively thin-walled and light, and which can be injection molded with a short cycle time. Also, a module with such double main ribs may be provided with a relatively large open surface. The main ribs can extend over at least a part of the main axis of the module in a corrugated fashion. By connecting the main ribs via longitudinal ribs extending in conveying direction, the tensile strength of the module can be augmented, and the stability of products on the top of the body part can be augmented. The longitudinal ribs preferably extend between opposite coupling elements. The body part may further be provided, for further strength and stability enhancement, with a central rib extending over the main axis, which connects the longitudinal ribs. The longitudinal ribs and the central rib preferably have a wall thickness that is less than the main ribs, e.g. a wall thickness that is about half, or less, of the wall thickness of the main ribs. Within this context, half of the thickness should be understood as a thickness that is in between 0.3 and 0.7 times the wall thickness of the main ribs, in particular between 0.4 and 0.6 times, and specifically 0.5 times. 
     When the longitudinal ribs and central rib at least at the top of the body part form a lattice, between which the openings are formed, a module configuration can be obtained with a top that is relatively open, and yet provides a relatively high product stability. A part of the lattice advantageously forms the top of the drive chamber, so that this chamber is properly cleanable. 
     By leaving the body part at the location of the dividing plane free of longitudinal ribs, the module can be relatively easily divided into two halves, for example by sawing it through. Advantageously, the body part may then be provided with guide elements extending in conveying direction and bordering on the dividing plane. Such guide elements may guide, for example, a band saw, but may also advantageously contribute to the formation of a relatively smoothly formed side surface of the module half. 
     By giving the body part, in a direction transverse to the conveying direction, a dimension of about 17 cm, in particular 169.8 mm, or about 6″, and the divided module halves a dimension of about 8.5 cm, in particular 84.8 mm, or 3″, the module can be well employed in standardized metric or Imperial systems, respectively. 
     The invention also provides a modular conveyor mat, comprising a plurality of in conveying direction successive rows of modules of the above-mentioned type, which are coupled with the aid of hinge pins extending transversely to the conveying direction, and wherein in conveying direction successive modules are staggered with respect to each other according to a brick pattern, and wherein in at least a number of rows of modules a module is included whose body part is divided along the dividing plane, and wherein more particularly at least a number of in conveying direction successive rows consist alternately of undivided modules and of a combination of undivided modules and at least a module whose body part is divided along the dividing plane. 
     It is then preferred that two halves of a module divided along the dividing plane are each included with a side thereof on a longitudinal edge of the conveyor mat. The divided module halves of a module may then be located with their sides on the same longitudinal edge of the conveyor mat, or on opposite longitudinal edges. The module halves may have been rotated 180° with respect to each other about an axis transverse to the top of their body parts. Advantageously, with both halves of the divided module, the hinge part located on the side of the body part and bordering on the longitudinal edge of the conveyor mat comprises a locking provision for locking the hinge pin against migration transverse to the conveying direction. 
     As regards the disclosure made here, it is noted that the above-mentioned technical features, whether or not included in a dependent claim, may also each in itself be used to advantage, and if desired can also be used in random combinations in a module for a modular conveyor mat. This also concerns combination of the discussed features separately or in random combination with a module for a modular conveyor mat in which not all features of claim  1  are used, for example a module including a body part extending transversely to a conveying direction along a main axis between two sides, with a top for carrying products to be conveyed and a bottom for cooperation with a conveyor track, and with coupling elements at both a front and a rear as viewed in conveying direction, and wherein coupling elements at both the front and the rear comprise a series of hinge parts and receiving spaces, so that hinge parts and receiving spaces can interdigitate with receiving spaces and hinge parts of in conveying direction successive similar modules, and successive modules are hingedly coupled with the aid of hinge pins extending transversely to the conveying direction. 
    
    
     
       The invention will be further elucidated on the basis of a non-limitative exemplary embodiment which is represented in a drawing. In the drawing: 
         FIG.  1    shows a schematic perspective top view of a module for a modular conveyor mat; 
         FIG.  2    shows a schematic perspective bottom view of the module of  FIG.  1   ; 
         FIG.  3    shows a schematic front view of the module of  FIG.  1   ; 
         FIG.  4    shows a perspective top view of a modular conveyor mat assembled on the basis of modules of  FIG.  1   ; 
         FIG.  5    shows a detail of a longitudinal edge of the conveyor mat of  FIG.  4    in which hinge pins are represented and in which the hinge parts of greater width on the longitudinal edge are provided with a locking provision for locking the hinge pin, formed by a receiving provision with a detachable closing clip received therein; and 
         FIG.  6    shows a schematic perspective bottom view of the conveyor mat of  FIG.  4   . 
     
    
    
     It is noted that the figures are merely schematic representations of a preferred embodiment of the invention. In the figures, identical or corresponding parts are represented with the same reference numerals. 
       FIGS.  1 - 3    show a module  1  for a modular conveyor mat  2  which is represented in  FIGS.  4  and  5   . Referring to  FIGS.  1 - 5   , the module  1  comprises a body part  4  extending transversely to a conveying direction P between two sides  3 A,  3 B along a main axis A. The body part has a top  5  for carrying products to be conveyed and a bottom  6  for cooperation with a conveyor track, not represented. The body part  4  is provided with coupling elements  9  at the front  7  and rear  8  as viewed in the conveying direction P. The coupling elements  9  at both the front  7  and the rear  8  comprise a series of successive hinge parts  10  and receiving spaces  11  alternating transversely to the conveying direction. Opposite coupling elements  9  at the front  7  and the rear  8  of the body part  4  form a pair  12  of a hinge part  10  and a correspondingly formed receiving space  11 . Hinge parts  10  and receiving spaces  11  can interdigitate with receiving spaces  11 ′ and hinge parts  10 ′ of a similar module  1 ′ successive in conveying direction. Successive modules  1 ,  1 ′ can be hingedly coupled with the aid of hinge pins  14  extending transversely to the conveying direction and reaching through hinge bores  13  provided in the hinge parts  10 . Successive modules can thus pivot relative to each other about an axis parallel to the conveying surface T formed by the tops of successive modules and transverse to conveying direction P, so that the conveyor mat for instance can circulate in an endless loop around a set of gears. 
     The body part  4  is provided in the middle with a dividing plane D extending parallel to the sides, and along which the module is divisible into two module halves  1 A,  1 B. In the front view of  FIG.  3    it can be properly seen that the top  5  on both sides of the dividing plane D slopes down obliquely in order to counteract sharp edges after division coming to lie in the conveying surface. 
     The pairs of coupling elements  9   z  located on the sides  3 A,  3 B are implemented, as viewed in the direction of the main axis A, with a greater width B than the width b of neighboring coupling elements  9  of the body part  4 . Further, pairs of coupling elements  9   d  located on either side of the dividing plane D of the module  1  are also implemented with the same width as the coupling elements  9   z  located on the sides with the greater width B mentioned. The width b of the other coupling elements  9  is chosen to be mutually equal to that of the neighboring coupling elements; the series of coupling elements  9  between the wide coupling elements  9   z  on the sides  3 A,  3 D and the wide coupling elements  9   d  which border on the dividing plane have an equal and hence narrower width b. 
     The coupling elements  9   z ,  9   d  implemented with greater width have, in this example, double the width of the other coupling elements  9 , specifically a twice as large a width along the main axis A. 
     The hinge parts  10 B of greater width on the side  3 A of the module lie diametrically with respect to both the hinge parts  10 B on the opposite side  3 B of the body part  4  and the side surface  15 A, located on the same module half  1 A, and bordering on the dividing plane D. This also applies to the receiving spaces  11 B. Both the modules  1  themselves and the module halves  1 A,  1 B resulting after division are 180° reversible about an axis Z transverse to the top of the body part, so that the front  7  and rear  8  can be interchanged for coupling with a next module  1 ′. 
     Both hinge parts located on a side of the body part comprise a locking provision  16  for locking the hinge pin against migration transverse to the conveying direction P. The locking provision is implemented as a blocking element adjustable between a release position and a blocking position and which in the release position leaves the hinge bore of the hinge part clear, and in the blocking position extends into the hinge bore and hinders passage of a hinge pin  14  through the hinge bore. 
     The locking provision  16  in this example is implemented as a receiving provision for a detachable closing element, in particular a closing clip  17 . This receiving provision has as an advantage that it can be applied on both sides of the module, and that, when on a side no closing element is arranged, it does not hinder passage. The hinge parts  10 B bordering on the dividing plane D each comprise two hinge part halves  10 BA and  10 B 2  separated by a notch  18 . The body part  4  is further provided, at the bottom  6  of only one of the module halves  1 A bordering on the dividing plane D, with a guide element  19  for cooperation with guide strips of the track on which the conveyor mat is supported. The guide element  19  in this exemplary embodiment is integrally formed with the body part  4  and is implemented with two spaced-apart downwardly extending guide surfaces  20  which extend parallel to the side  3 A of the module. Only the module half  1 A has a guide element. 
     The body part  4  is further provided, at the bottom on both sides of the dividing plane D, with a drive chamber  21  for cooperation with teeth of a driving gear, so that both module halves  1 A,  1 B have a drive chamber  21 . The drive chamber extends in the longitudinal direction along main axis A, along three unwidened coupling elements  9 . 
     The body part  4  is further provided with through openings  22  extending between the top  5  and bottom  6 , for cleaning the conveyor mat and/or products to be conveyed thereon. 
     The receiving spaces  11  are provided, near the body part  4 , with an overhang  22  which, when, as can be seen in  FIG.  4   , a coupling element  10  is received in the receiving space  11 , forms an additional opening  23  extending between the top and bottom to make an extra portion of the conveying surface T of the conveyor mat  2  liquid-transmissive. In  FIG.  3    it can be properly seen that the openings and additional openings towards the bottom remain the same or increase in size, for the sake of cleanability. 
     The body part  4  is further provided with two main ribs  24 A,  24 B extending in a corrugated fashion along the main axis A, each carrying hinge parts  10 , and which are spaced apart with a mutual intermediate distance with respect to the main axis A. The pointed, parallel main ribs  24 A,  24 B are connected via longitudinal ribs  25  extending in conveying direction P between opposite coupling elements  10 ,  11 . The body part  4  is further provided with a central rib  26  extending over the main axis, and connecting the longitudinal ribs. The longitudinal ribs  25  and the central rib  26  in this example have a wall thickness of 0.5 times the wall thickness of the main ribs. The longitudinal ribs  25  and the central rib  26  form, at least at the top  5  of the body part, a lattice  27  between which the openings  22  are formed. In  FIG.  5    it can be properly seen that the lattice  27  also forms the top of the drive chamber  21 , so that the latter is open at the top and hence is properly cleanable. 
     The body part  4 , at the location of the dividing plane D, has been left free of longitudinal ribs  26 , so that the module can be relatively simply sawn into two halves. The body part  4  is provided with guide elements  28  extending in the conveying direction P, bordering on the dividing plane D, and which can guide a band saw upon dividing of a module into module halves  1 A,  1 B, and which after division form relatively smoothly formed side surfaces  15 A,  15 B of the respective module halves  1 A,  1 B. 
     The body part  4  has, in a direction transverse to the conveying direction P, a dimension of 17 cm, in particular a nominal specification dimension of 69.8 mm and the divided module halves each have a dimension of 8.5 cm, in particular a nominal specification dimension of 84.8 mm. 
       FIGS.  4 ,  5  and  6    show a modular conveyor mat  2 , comprising a number of in conveying direction successive, alternating rows  29  and  29 ′ of modules  1  which are coupled with the aid of hinge pins extending transversely to the conveying direction P across the width of the conveyor mat  2 . In conveying direction P, successive modules are staggered with respect to each other according to a brick pattern. In the rows  29 ′, at longitudinal edges  30  of the conveyor mat  2 , a module  1  has been included whose body part has been divided along the dividing plane into two module halves  1 A,  1 B which have been rotated 180° relative to each other about an axis Z transverse to the top  5  of their body parts  4 . With both module halves  1 A,  1 B of the divided module  1 , the hinge part  10   xl  which borders on the longitudinal edge  30  of the conveyor mat  2  is provided with a locking provision  16  for locking the hinge pin against migration transverse to the conveying direction. The intermediate rows  29  comprise two undivided modules  1  which have, or have not, been turned 180° relative to each other about an axis Z transverse to the top  5  of their body parts  4 . In  FIG.  5    it is shown that the hinge parts  10   xl  of greater width at the longitudinal edge  30  of the conveyor mat  2  are provided with a locking provision  16  which is formed by a receiving provision having a detachable closing clip  17  received therein. 
     The wide hinge parts  10   xl  are received in corresponding wide receiving spaces  11   xl . With successive modules  1 ,  1 ′, which in the brick pattern are staggered with respect to each other transversely to the conveying direction, the additional wider coupling elements  9   d  bordering on the dividing plane D accommodate the wider coupling elements  9   z  located on the sides. With both modules  1 , the hinge part  10   xl  located on the side  3 A or  3 B of the body part  4  and bordering on the longitudinal edge  30  of the conveyor mat  2  is provided with a locking provision  16  for locking the hinge pin  14  against migration transverse to the conveying direction P. 
     The maximum dimension of the opening and additional openings in a conveying surface T formed by the tops  5  of successive modules  1 ,  1 ′ is in this example about 3 mm and the conveying surface T is about 55% open. 
     As shown in  FIG.  6   , the conveyor mat  2  is made up of two kinds of long modules  1 , namely long modules with guide elements and long modules without guide elements  19 . If desired, the conveyor mat may be assembled from one kind of long modules, for example when no guide elements  19  are needed, or when the guide elements are detachably connected with the modules. 
     The invention is not limited to the exemplary embodiment represented here. In particular, at the location of the dividing plane a break provision may be arranged. In addition, the top of the body part may be of closed design, i.e. substantially without openings. Also, the coupling elements, in particular the hinge parts may be designed differently. 
     Such variants will be clear to the skilled person and are understood to fall within the scope of the invention as set forth in the following claims. 
     REFERENCE NUMERALS 
     
         
         
           
               1  Module 
               1 A,  1 B Module half 
               2  Conveyor mat 
               3 A,  3 B Side 
               4  Body part 
               5  Top 
               6  Bottom 
               7  Front 
               8  Rear 
               9  Coupling elements 
               9   z  Coupling element at side 
               9   d  Coupling element at dividing plane 
               10  Hinge part 
               10   xl  Wider hinge part 
               10 A,  10 B Hinge part half 
               11  Receiving space 
               11   xl  Wider receiving space 
               12  Pair of coupling elements 
               13  Bore 
               14  Hinge pin 
               15 A,  15 B Side surface 
               16  Locking provision 
               17  Closing clip 
               18  Notch 
               19  Guide element 
               20  Guide surface 
               21  Drive chamber 
               22  Opening 
               23  Additional opening/Overhang 
               24  Main rib 
               25  Longitudinal rib 
               26  Central rib 
               27  Lattice 
               28  Guide surface 
               29  Row 
               30  Longitudinal edge 
             A Main axis 
             b Width normal coupling element 
             B Width wider coupling element 
             D Dividing plane 
             T Conveying surface 
             Z Rotation axis