LINK BELT FOR CONVEYING PRODUCTS, WITH LINKS PROVIDED WITH GUIDING MEANS

Abstract: Link belt (1) provided with links (2, 3, 4, 5, 6) and hinge pins (7) for conveying products. The links (2, 3, 4, 5, 6) are made from a compression mouldable or castable plastic material. Each link comprises a number of flat link members each with a recess (14) defined by pulling arms (15, 16) and each with a slotted hole (20). Each link has a hinge pin (7) with a centre line which can be moved in the plane of the link belt (1) through the slotted holes of the link members of an adjacent link. Adjacent pulling arms 16, 15') of two adjacent link members (8, 9) of a link (2) are connected by a bush (17) in which the hinge pin of said link (2) fits, at least one end of each hinge pin being attached to an outer bush (18). The end wall of the slotted hole (20) of at least one of the outer link members has a semi-circular wall, the end wall of said slotted hole forming a line (21) which encloses an angle unequal to 0 DEG with the centre line (22) of the hinge pin (7') which fits in said slotted hole (20). Each outer link member comprises a rolling element which parlty protrudes from the link member.

Description: LINK BELT FOR CONVEYING PRODUCTS, WITH LINKS PROVIDED WITH GUIDING MEANS The present invention relates to a link belt provided with links and hinge pins for conveying products, the link belt defining a plane, the links being made from a compression mouldable or castable plastic material or similar material, each link comprising a number of flat link members each with a recess defined by pulling arms and each with a slotted hole, each link having a hinge pin with a centre line which can be moved in the plane of the link belt through the slotted holes of the link members of an adjacent link, the adjacent pulling arms of two adjacent link members of a link being connected by a bush in which the hinge pin of said link fits, at least one end of each hinge pin being attached to an outer bush having an inside which is attached with an outer pulling arm, the end wall of the slotted hole of at least one of the outer link members having a semi-circular wall, the end wall of said slotted hole forming a line which encloses an angle unequal to 0° with the centre line of the hinge pin which fits in said slotted hole. Such a link belt is known from European patent application 0 427 337, and can for instance be used to convey bakery products over a track in treatment devices. The length of such a link belt can be considerable, while the track may have some bends. In order to have the link belt run reproducibly through the treatment device, the treatment device contains side guides for the link belt which engage the outer parts of the link belt. Because of the inevitable contact between the side guides and the link belt, frictions arise, particularly in the bends of the track, which not only cause wear but also with certain lengths of link belt require a considerable degree of driving or - 2 - on the other hand only renders shorter lengths of link belt usable. It is among other things an object of the present invention to provide a link belt with links provided with a number of link members for conveying products, in which the friction between the link belt and the side guides is considerably reduced. This does not only result in reducing the wear of the side guide and the link belt but also the degree of driving can be reduced for a certain length of link belt, or on the other hand with the same drive a greater length of link belt can be used. All this among other things leads to a cost reduction. To that end a link belt provided with links and hinge pins for conveying products of the kind described above according to the invention is characterized in that a number of the outer link members comprise a rolling element which partly protrudes from the link member. By using rolling elements in the link belt the known sliding friction is transformed into a rolling friction which considerably reduces the degree of friction between the link belt and the side guide. The use of rolling elements according to the invention is not limited to the link belt as described in European patent application 0 427 337, but can also be used with other link belts, the links of which are made from a compression mouldable or castable plastic material, or similar material. According to a further aspect of the invention the invention provides a link belt provided with links and hinge pins for conveying products, the link belt defining a plane, the links being made from a compression mouldable or castable plastic material or similar material, each link comprising a number of flat link members each with a recess defined by pulling arms and each with a slotted hole, each link having a hinge pin with a centre line which can be moved in the plane of the link belt through the slotted holes of the link members of an adjacent link, the adjacent pulling arms of two adjacent - 3 - link members of a link being connected by a bush in which the hinge pin of said link fits, at least one end of each hinge pin being attached to an outer bush having an inside which is attached with an outer pulling arm, the end wall of the slotted hole of at least one of the outer link members having a semi-circular wall, characterized in that a number of the outer link members comprise a rolling element which partly protrudes from the link member. According to another aspect the invention provides a link belt with links provided with a number of link members for conveying products, the link belt defining a plane, the links being made from a compression mouldable or castable plastic material or similar material, characterized in that a number of the outer link members comprise a rolling element which partly protrudes from the link member. Preferably each outer link member comprises a rolling element which partly protrudes from the link member. However, depending on the construction it is possible to provide only a part of the outer link members with rolling elements, for instance half or a third of the total number of link members. A preferred embodiment of a link belt according to the invention is characterized in that each of the rolling elements is placed such in the link member concerned that when exerting lateral forces on the link belt no moment is exerted on the link belt. In this way it is prevented that at a certain degree of lateral forces at least a part of the link belt is lifted unwantedly. When the rolling element is a rotatable disc, this can be realized in a simple manner by situating the central plane of each of the rotatable discs in the central plane of the link belt. Preferably the rolling element comprises a rotatable disc, which can be accommodated in a flat link belt in a mechanically simple manner. - 4 - Preferably each outer link member is provided with a supporting construction integrated therewith for rotatably supporting the rolling element, in which it is further preferred that the supporting construction is simultaneously manufactured with the links from the same compression moul- dable or castable plastic material. In this way a link member with supporting construction can be made in one progress of a production process, after which the rolling element can be placed in the supporting construction. The invention will be elucidated below on the basis of a drawing, in which by way of example an embodiment of a link belt according to the present invention is shown, in which: Figure 1 schematically shows in top view a part of a known link belt; Figure 2 schematically partially in cross-section shows a part of an outer link member of the known link belt; Figure 3 shows a part with bends and straight parts of a track of a link belt through a treatment device; Figure 4 schematically and partially shows a cross-section along the line IV-IV in figure 3, showing the side guide and the track construction; Figure 5 schematically shows in top view a part of a link belt according to the present invention, in which only the outer link members in the inner radius of the link belt are shown; Figure 6 shows a schematical top view of an outer link member according to figure 5; Figure 7 shows the outer link member according to figure 6, now partially - 5 - in cross-section; Figure 8 shows a cross-section along the line VIII-VIII in figure 6 of an outer link member. In figure 1 a part of a known link belt according to EP-A-0 427 337 is schematically shown in top view, while in figure 2 a part of an outer link member of the known link belt is schematically shown partially in cross- section. The known link belt 1 is provided with a large number of links, of which the links 2, 3, 4, 5, 6 are shown and comprises hinge pins 7. The link belt 1 is suitable for conveying products such as bakery products or any other kind of product, through a treatment device and defines a plane. The length of such a link belt may be some hundreds of meters. The links 2, 3, 4, 5, 6 are made from a compression mouldable or castable plastic material or similar material. Each link 2, 3, 4, 5, 6 contains a number of flat link members 8, 9, 1 0, 1 1 , 1 2, 1 3, in the shown example six, although any other number is also possible. Each link member 8-1 3 has a recess 14 defined by pulling arms 1 5, 1 6 and a slotted hole 20 (see figure 2) for accommodating the hinge pin concerned. Each hinge pin 7 has a centre line and can be moved in the plane of the link belt 1 through the slotted holes of the link members of an adjacent link. Here adjacent pulling arms 1 6, 1 5' of two adjacent link members 8 and 9 of a link 2 are connected by a bush 1 7 in which the hinge pin concerned of said link 2 fits. At least one end of each hinge pin (for instance 7) is attached to an outer bush 1 8 which has an inside 1 9 which is attached with an outer pulling arm 1 5" . The end wall of the slotted hole 20 of at least one of the outer link members has a semi-circular wall, in which the end wall of said slotted hole forms a line 21 which encloses an angle a, unequal to 0° , with the centre line 22 of the hinge pin 7' which fits in said slotted hole 20. This angle a is chosen such depending on the bends to be made by the link belt in the track that tensile forces in these bend-portions are better accom- - 6 - modated. For a further description of the known link belt EP-A-0427337 is referred to. Figure 3 shows a part of an illustrative track a link belt 1 can make through a treatment device. The track can have a number of bends, such as U- bends, S-bends, squared bends or bends with another angle; and also has a number of straight parts. In order to let the link belt 1 run reproducibly through the treatment device, the treatment device comprises side guides 40, 41 (see figure 4) for the link belt 1 , which abut the outer members of the link belt 1 . In reality all this is made such that one of the outer edges of the link belt abuts one of the side guides, while there is some play between the other outer edge of the link belt and the other side guide. The treatment device further comprises a supporting construction 46 for the link belt, which for instance comprises supporting elements 42, 43, 44, 45, the supporting elements 44 and lower supports support the returning link belt. This supporting construction will not be further described in detail here, as such constructions are known to the expert and the invention does not relate to the specific form of such a construction. Because of the inevitable contact between the side guides 40 or 41 and the link belt 1 , frictions arise particularly in the bends of the track, which do not only cause wear but also with certain lengths of link belt require a considerable degree of driving or on the other hand only render shorter lengths of link belt usable. According to the invention the degree of friction is considerably reduced by providing each outer link member with a rolling element (for each outer part of the link belt generally indicated with 47, 48, respectively, in figure 4) which partly protrudes from the link member. By using rolling elements in the link belt the sliding friction with the known link belt is transformed into a rolling friction which considerably reduces the degree of friction between the link belt and the side guide. - 7 - Figure 5 schematically shows in top view a part of a link belt according to the present invention, in which only outer link members 50, 51 , 52, 53 are shown. In this example each outer link member 50, 51 , 52, 53 is provided with a rolling element 54, 55, 56, 57, respectively, which protrudes from the link member concerned and contacts the side guide 40. Although in figure 5 only one side of the link belt is shown, it will be clear that the outer link members on the other side of the link belt are also provided with rolling elements. Depending on the construction, it is also possible that only each second or third outer link member is provided with a rolling element, or even another part of the total number of outer link members. It also an obvious advantage of the link belt according to the present invention that it can run along bends with counter directions. Preferably each of the rolling elements is placed such in the link member concerned, that when exerting lateral forces on the link belt no moment is exerted on the link belt, in this way it is prevented that too large a degree of lateral forces lifts at least a part of the link belt. The rolling element may for instance have the shape of a sphere, or a cylinder, but with a flat link belt it is preferred to design the rolling element as a rotatable disc, so that the flat shape of the link belt, and the advantages connected to it, are maintained. In particular for preventing the creation of moments on the link belt with lateral forces on it, the use of rotatable discs as rolling element is advantageous. By situating the central plane of each of the rotatable discs in the central plane of the link belt, the creation of such moments can be prevented in a mechanically simple manner, because the forces are active in the central plane of the link belt. Figure 6 schematically shows a top view of one outer link member accor- ding to figure 5, in which the rolling element is a rotatable disc 60, and in which for the sake of clarity of the drawing the hinge pin is left out. Figure 7 shows the outer link member according to figure 6, now partially in - 8 - cross-section and figure 8 a cross-section along line Vlll-VIII of figure 6 of the outer link member, in order to show the rotatable disc 60 better. Although each rolling element can be attached to each outer link member by a separate connection part, it is preferred to provide each link member with a supporting construction integrated therewith for rotatably supporting the rolling element, for instance a rotatable disc. Preferably the supporting construction comprises two flat link plate mem- bers 80, 81 placed parallel to the plane of the link belt and at a distance from each other, between which plate members the rotatable disc 60 is placed. The rotatable disc 60 is provided with a central opening 82 for attachment to the supporting construction 80, 81 , in which opening an axis 83 is placed. The ends of the axis 83 are each attached to a link plate member concerned. In order to simplify the manufacturing process of the inventive link belt, and to obtain a manageable realisation of the rolling elements with the link belt, the supporting construction is preferably simultaneously made with the links, for instance during the same compression moulding or casting process in which the link belt is made from plastic material.

Claims: -9- Ciaims 1 . Link belt provided with links and hinge pins for conveying products, the link belt defining a plane, the links being made from a compression mouldable or castable plastic material or similar material, each link comprising a number of flat link members each with a recess defined by pulling arms and each with a slotted hole, each link having a hinge pin with a centre line which can be moved in the plane of the link belt through the slotted holes of the link members of an adjacent link, the adjacent pulling arms of two adjacent link members of a link being connected by a bush in which the hinge pin of said link fits, at least one end of each hinge pin being attached to an outer bush having an inside which is attached with an outer pulling arm, the end wall of the slotted hole of at least one of the outer link members having a semi-circular wall, the end wall of said slotted hole forming a line which encloses an angle unequal to 0° with the centre line of the hinge pin which fits in said slotted hole characterized in that a number of the outer link members comprise a rolling element which partly protrudes from the link member. 2. Link belt provided with links and hinge pins for conveying products, the link belt defining a plane, the links being made from a compression moul- dable or castable plastic material or similar material, each link comprising a number of flat link members each with a recess defined by pulling arms and each with a slotted hole, each link having a hinge pin with a centre line which can be moved in the plane of the link belt through the slotted holes of the link members of an adjacent link, the adjacent pulling arms of two adjacent link members of a link being connected by a bush in which the hinge pin of said link fits, at least one end of each hinge pin being attached -10- to an outer bush having an inside which is attached with an outer pulling arm, the end wall of the slotted hole of at least one of the outer link members having a semi-circular wall, characterized in that a number of the outer link members comprise a rolling element which partly protrudes from the link member. 3. Link belt with links provided with a number of link members for conveying products, the link belt defining a plane, the links being made from a compression mouldable or castable plastic material or similar material, characterized in that a number of the outer link members comprise a rolling element which partly protrudes from the link member. 4. Link belt according to claim 1 , 2 or 3, characterized in that each outer link member comprises a rolling element which partly protrudes from the link member. 5. Link belt according to claim 1 , 2, 3 or 4, characterized in that the rolling element comprises a rotatable disc. 6. Link belt according to any one of the preceding claims, characterized in that each of the rolling elements is placed such in the link member concerned that when exerting lateral forces on the link belt no moment is exerted on the link belt. 7. Link belt according to claim 5 and 6, characterized in that the central plane of each of the rotatable discs is situated in the central plane of the link belt. 8. Link belt according to any one of the preceding claims, characterized in that each outer link member is provided with a supporting construction integrated therewith for rotatably supporting the rolling element. 9. Link belt according to claim 8, characterized in that the supporting construction comprises two flat link plate members placed parallel to the plane of the link belt and at a distance from each other, between which plate members the rolling element is placed. 1 0. Link belt according to claim 5 and 9, characterized in that the rotatable disc has a central opening in which an axis is placed and the ends of the axis each being attached to a link plate member concerned. 1 1 . Link belt according to any one of the preceding claims 8, 9 or 10, characterized in that the supporting construction is simultaneously manufactured with the links from the same compression mouldable or castable plastic material.

Inventors: PASCH LOTHAR, PASCH, LOTHAR
Applicants: KAAK JOHAN H B, PASCH LOTHAR, KAAK, JOHAN, HENDRIK, BERNARD, PASCH, LOTHAR
Application year: 1999
Main classification: B65G17
IPC codes: B65G17