CONVEYOR ASSEMBLY

Abstract: Conveyor assemblies which by means of an endless chain move foodstuff packages between different processing machines are customary in e.g. the dairy industry. Up to now the conveyor assembly generally was "tailor-made" for each dairy, which entails unnecessary cost and other difficulties. In accordance with the present invention a conveyor assembly of a modular design is proposed which makes it easily adaptable to different needs and localities. More particularly, an intermediate guideway (4) for an endless chain (3) is made use of as a spacer element between supporting sides (2) of the assembly, thus providing a simple and stable construction. Similarly shaped fastening devices (6), moreover, serve as joint pieces between different guideway sections, thus facilitating fitting-up and reducing cost.

Description: The present invention relates to a conveyor assembly with supporting parts able to be joined together to the required length, which comprises two supporting sides which between them have a slideway for an endless chain. Conveyor assemblies of the type which by means of a motor-driven endless belt or an endless chain move goods between different positions have a wide range of applications. Within e.g. the dairy industry chain conveyors are made use of for the transport of, among others, packing containers for milk between, or from, different packaging or processing machines. Up to now conveyor assemblies for this purpose generally were "tailor-made" with the help of a very great number of more or less specially manufactured components. The result frequently has been an expensive and complicated design, which owing to the large number of components was difficult to fit up, and which owing to the great number of joints tended to become unstable after prolonged usage. Since pockets and recesses are unavoidable at the points of joining the cleaning is made considerably more difficult, which is a major disadvantage in the foodstuff industry. A frequently defective guidance of the conveying chain also entails unnecessary wear on the chain as well as on the packages and consequent fouling of the system. A conveyer assembly in accordance with the opening part of claim 1 is described in FR-A-2 446 383, SE-B-423 523 and US-A-3 508 642. However, there are very often problems in case the chain or belt, respectively, on which articles are to be conveyed are not sufficiently supported by supporting parts and slideways, respectively. It is an objective of the invention to provide a conveyer assembly of such type which avoids such disadvantages and which prevents the lifting of the chain or belt at such places of unsufficient supporting. According to the present invention this objective is solved by the characterizing part of claim 1. At the place of unsufficient supporting of the chain by said slideway, a lateral projection projects from one of said supporting sides into the space between both of them thereby pressing the chain towards the other one of said supporting sides. Situated at about the same place but adjacent the other one of said supporting sides a sliderail co-operates with a surface of said chain thereby hindering that the chain will be lifted. Furthermore, it is advisable to stretch and load, respectively, the chain or belt by an additional wheel according to sub-claim 6. Such element is described in US-A-1 497 619. According to the invention it is advisible to freely suspend the wheel in the chain. Preferred embodiments of the arrangement in accordance with the invention have been given, moreover, the characteristics which are evident from the subsidiary claims. By making use of the slideway as a spacer element between the supporting sides, the latter after fitting-up will be fixed at a predetermined distance from one another and in a very steady and immovable manner which is not impaired during prolonged operation. The modular system ensures that the conveyor assembly will be easy to fit-up and to adjust and simple to adapt to local conditions, at the same time as the relatively small number of joints and other difficultly accessible recesses makes for a satisfactory cleaning effect. The effective stretching and the guiding of the conveying chain and the goods transported on the same minimize wear and ensure good function even after usage over a long period. A preferred embodiment of the conveyor assembly in accordance with the invention will now be described in more detail with special reference to the attached schematic drawings which only show the details indispensable for an understanding of the invention. Fig.1 shows in perspective a part of the conveyor assembly in accordance with the invention during fitting-up. Fig.2 shows partly in section the conveyor assembly in accordance with Fig.1. Fig.3 shows a portion of a supporting part from the top, the guides and brackets mounted on the supporting part having been removed for the sake of clarity. Fig.4 shows from the side and partly in section a portion of a supporting part with a chain stretching arrangement in accordance with the invention. Fig.5 is a section of a part of the chain stretching arrangement in accordance with Fig. 4 The conveyor assembly according to the invention comprises a number of supporting parts 1 of different predetermined lengths which can be joined together to the desired length. Each supporting part 1 comprises two mirror-symmetrical supporting sides 2 between which run the upper and lower portion respectively of a conveying chain 3. The distance between the supporting sides is determined by slideways 4,5 located between the supporting sides, on which run the two portions of the chain 3. In other words, the slideways 4,5 serve as spacer elements between the supporting sides 2 so that these are fixed at a predetermined distance from one another. More particularly, longitudinal edges of the slideways 4,5 engage in grooves in fastening devices 6 which are located at uniform intervals on the inside of the supporting sides 2. The said grooves in the fastening devices 6 are adapted so that the slideways 4,5 assume a position at a substantially right angle to the vertical surfaces of the supporting sides 2 which means that the supporting sides 2 together with the fastening devices 6 and the slideways 4,5 form a unit of substantially square cross-section (Fig.2), which makes the supporting parts 1 particularly firm and stiff against torsion. The supporting sides 2 and the fastening devices 6 are pressed together against the slideways 4,5 with the help of screws 7 and internally threaded sockets 8 which are located directly underneath the respective slideways 4,5 and extend through through-holes in the fixing devices 6 as well as the supporting sides 2. The V-shape of the grooves present in the fastening devices 6 entails that even a relatively loose tightening of the screws 7 causes a firm wedging of the slideways 4,5 in correct position, thus contributing effectively to the good precision and stability of the construction. In the fastening devices 6, moreover, a number of guide pieces 9 are present, which are manufactured from any suitable plastic material and are located directly above the upper surfaces of the slideways 4,5 so as to serve as lateral guides for the conveying chain 3 moving on the slideways 4,5. The upper, active portion of the conveying chain 3, when resting against the slideway 4, as is evident from Fig.2,is located with its upper surface above the two top edges of the supporting sides 2. To provide lateral guidance of the packing containers transported on the conveying chain 3, the conveyor assembly in accordance with the invention comprises a number of parallel guides 10 extending at a distance above the supporting sides 2 which are supported by means of vertical brackets 11 situated at uniform intervals along the supporting parts, which are provided with snap-on mountings for the guides 10. The brackets 11 are provided at their bottom ends with fastening holes, by means of which the brackets are joined to the supporting sides 2 and the fastening devices 6 with the help of the screws 7 mentioned earlier. The brackets 11 may be of varying design to allow adapting to the packing containers which are to be transported on the conveyor in question, and instead of the design shown the brackets 11 may be straight or bent outwards so that the distance between the guides 10 becomes greater and permits the passage of wider packing container on the conveyor. As mentioned earlier,each bracket 11 is situated at a predetermined point along the supporting side 2, which is predrilled.To make possible the attachment of the bracket 11, a fastening device 6 inside the supporting side is required, and at each bracket, therefore, the supporting sides 2 will be fixed at a certain distance from one another with the help of the screws 7 and the spacer sockets 8.The fastening devices 6 here are of a width which coincides with, or exceeds, the width of the brackets 11, but at the points where two supporting parts 1 are to be joined together another type of fastening device 6 occurs which is of appreciably greater width and, besides allowing the attachment of the brackets 11, also serves as a joint piece for the joining of two supporting parts to one another (Fig.1).The fastening device 6 or the joint piece here has been provided with four screw holes for joining the supporting sides 2 to one another and two further screw holes to make possible the attachment of brackets 11. The fastening devices 6 intended for bracket attachment as well as the fastening devices serving as joint pieces are of identical section which makes it possible to manufacture them in a simple manner from extruded aluminium. The brackets 11 too are manufactured in a manner which makes it possible to produce the parts with high precision and at relatively low cost. As is evident from the above, the conveying chain 3 during operation is located on the slideways 4,5 which are manufactured from extruded aluminium and provided with an upper surface or slideway of suitable low-friction material, e.g. thermoplastics. The thermoplastic material engages mechanically in the top surface of the aluminium section which is provided with an uneven profile, e.g. of dovetail-type (Fig.2). The lateral guidance of the chain 3 is provided by the guide pieces 9, which likewise are manufactured from low-friction material and are arranged at uniform intervals along the length of the supporting part, more particularly at the points where the fastening devices 6 are situated. The chain 3 thus rests under its own weight on the underlying slideway 4,5, which functions well except in the cases where the chain passes a lower lying portion of the conveyor, that is to say where the support parts are bent in vertical direction and form a "valley". At such points during operation of the conveyor the chain 3 will be stretched owing to the tensile force in the chain so that it tends to lift off the underlying slideway 4. The conveyor assembly in accordance with the invention has been provided, therefore, with elements adapted to prevent lifting of the chain, these elements (Fig.3) comprising a projection 12 for the lateral guidance of the chain underneath a slide rail 13 co-operating with the top surface of the chain. The projection 12 is of a width which substantially amounts to a third of the free space between two guide pieces 9 situated opposite one another and of a height which is equal to, or slightly less than, the height of the chain 3. The projection 12 is of an elongated convex shape and is situated along the inside of one supporting side 2 where it replaces a guide piece 9 so that the chain 3 when it passes the projection 12 is forced to move sideways underneath the slide rail 13 located at a recess in the upper part of the opposite supporting side 2, whose lower surface is a little above the top surface of the chain 3, and as a result of resting against the same prevents the chain 3 from being lifted when the chain is stretched. Packages transported on the chain 3 can continue unhindered straight on past the particular position of the supporting part, since they are guided during the passage by the slide rail 13 and the guides not shown in Fig.3, so that they slide partly on the chain 3, partly on the top surface of the projection 12. The chain 3 is of known design which is hinged in vertical as well as in horizontal direction. As mentioned earlier, it is of the greatest importance for optimizing the function of the conveyor assembly and for minimizing wear and thereby any instability arising, that the chain should be kept stretched with constant force during the whole time. This is ensured in the conveyor assembly in accordance with the invention with the help of a chain-stretching arangement 14 (Fig.4, 5) which is located at a suitable place along the conveyor assembly.There is an interruption in the lower slideway 5 at the location of the chain-stretching arrangement 14, where the support sides 2 are extended downwards by means of guide panels 15, 16. The chain 3 runs down between the guide panels 15, 16 and around a freely suspended wheel 17, which by its weight is adapted to produce the required stretching of the chain. The wheel 17 which is illustrated in more detail in Fig.5 is made of a material of appropriate weight, e.g. stainless steel, and comprises around its periphery a friction-enhancing arrangement, e.g. two rubber rings 18 on which rests the conveying chain 3. In the centre hole of the wheel 17 are two guide pins 19 which with the help of a helical compression spring 20 located between them are pressed against the two guide panels 15, 16 with a predetermined force, sot hat on movement of the wheel 17 the friction produced between surfaces of the guide pins 19 and the guide panels 15,16 facing one another produces braking of the movement of the wheel 17 and prevents unnecessary pivoting, above all in vertical direction, thus imparting to the return portion of the conveying chain 3 a steady movement and even progress . The weight of the wheel 17 can be adapted to the length of the chain which the chain-stretching arrangement 14 is intended to work with, so that optimum function is achieved. The chain 3 is conducted to the wheel 17 via wheels 21 located at the end parts of the slideway 5, which may be suspended so that they can rotate freely in the chain-stretching arrangement 14 or they may comprise a driving wheel which is connected to an electric motor, not shown, and adapted to propel the conveying chain along at a predetermined speed. Naturally the driving may be arranged also at some other, arbitrary point along the length of the conveyor assembly.Such an arrangement, however, is well-known and therefore does not have to be described in greater detail in this context The conveyor assembly in accordance with the invention with the help of the design described is made into a very flexible and easily installed system which may be adapted to a great number of different operational situations. With the help of conventional points arrangements and track curves of known type (e.g. of the type as described in the Swedish patent application 8502231-7) and other accessories known in themselves the conveyor assembly is particularly well suited for the handling of packing containers in the dairy industry.

Claims: Conveyer assembly comprising: a) supporting parts (1) being capable to be joined together to the required length and comprising a1) two supporting sides (2) as well as a2) a slideway (4) serving as spacer elements between said supporting sides (2) for fixing them at a predetermined distance from each other and b) at least one endless chain (3) or band, respectively, at least partially supported by said slideway (4), characterized in that a3) a lateral projection (12) projecting from one of said supporting sides (2) into the space between both supporting sides (2) is situated at a place at which the chain (3) is not supported by said slideway (4) and that a4) a sliderail (13) is situated at about the same place adjacent the other one of said supporting sides (2) co-operating with a surface of said chain (3). Conveyer assembly as claimed in claim 1, characterized in that said lateral projection (12) is situated along the inner side of said one of said supporting sides (2) and comprises an elongated convex shape towards the other one of them. Conveyer assembly as claimed in claims 1 or 2, characterized in that said lateral projection (12) has a width (between said supporting sides (2)) of about 1/3 of the free space between said two supporting sides (2) and two guide pieces (9) attached to said supporting sides (2) opposite each other. Conveyer assembly as claimed in anyone of the preceding claims, characterized in that said sliderail (13) is situated at a recess in the upper part of the opposite supporting sides (2). Conveyer assemply as claimed in claim 4, characterized in that the lower surface of said sliderail (13) is situated a little above the top surface of said chain (3). Conveyer assembly as claimed in anyone of the preceding claims, characterized in that said slideway (5) is interrupted and that said supporting sides (2) extend downward forming guide panels (15, 16) between which a wheel (17) is situated for stretching and loading, respectively, the chain (3). Conveyer assembly as claimed in claim 6, characterized in that said wheel (17) is freely suspending in said chain (3). Conveyer assembly as claimed in claims 6 or 7, characterized in that , said wheel (17) is guided by a guide pin (19) which is located in a center hole of said wheel (17) and is pressed outwards against the guide panels (15, 16) by a spring (20). Conveyer assembly as claimed in anyone of the preceding claims, characterized in that said slideways (4) and/or guide pieces (9) comprise a material of low-friction. Conveyer assembly as claimed in anyone of the preceding claims, characterized in that guides (10) are situated at a distance above said supporting sides (2) for laterally guiding packaging containers to be conveyed on said chain (3) and belt, respectively. Conveyer assembly as claimed in claim 1, characterized in that said supporting sides (2) comprise brackets (11) being provided with snap-on mountings for said guides (10).

Inventors: SJOESTRAND, UNO, Sjöstrand, Uno
Applicants: AKTIEBOLAGET PROFOR
Application year: 1987
Main classification: B65G21
IPC codes: B65G21