Patent Application
20210229923
This patent application claims priority to European application EP 20153546.5, filed on 24 Jan. 2020, which is incorporated by reference as if fully recited herein.
The present invention relates to a conveyor belt unit for a dynamic checkweigher with a configuration-changing mechanism, in particular a conveyor belt unit with a belt body, which has at least one conveyor roller each arranged at the ends in transport direction and contrary to the transport direction, and wherein the conveyor belt unit is provided with a conveyor belt movably arranged across the belt body and the rollers.
Dynamic checkweighers are a key element of quality control in the manufacture of pharmaceutical and cosmetic products, foodstuffs, beverages as well as in the logistic, chemical, automotive and metal-processing industry. They not only improve the exploitation of existing resources but also aid in meeting national directives, calibration regulations and industry standards. An effective checkweigher system offers protection against product defects and lowers overall operating costs.
A dynamic checkweigher is a system, which weighs the goods while guiding them over the weighing unit within the production line, which classifies the goods into predefined weighing zones and which sorts or channels the goods according to weight classification. Checkweighers are used in a wide variety of fields comprising for example:
checking the products for underweight/overweight
adherence to legal regulations as regards net weight of packaged goods
reduction of product waste by using the weight values obtained by means of the checkweigher for adjusting the filling machines
classification of goods according to weight
measuring and recording the output of the production plant/line
verification of quantities by means of weight.
With checkweighers 100% of the products of a product line are weighed. This means that also all product data is collected for product counting, batch tracking and production statistics.
A checkweigher system normally consists of the following conveyor belt units: feed belt unit, weighing belt unit, discharge belt unit with sorting device and weighing terminal with user interface. The weighing belt unit situated between feed belt unit and discharge belt unit is mounted via a carrier frame on a load cell, which dynamically records the weight of the product as it is guided over the weighing belt unit. The two most frequently used weighing technologies for checkweighers are load cells with strain gauge or load cells operating according to the principle of electromagnetic force compensation (EFC). After being transported over the weighing belt unit the products are carried away by a discharge belt unit arranged downstream of the weighing belt unit. Products with incorrect weight are detected during the dynamic weighing process and are ejected by a sorting-out device, as a rule transversely to the transport of the products which takes place in longitudinal direction.
One of the above-mentioned conveyor belt units may for example be a weighing conveyor belt moved over a dynamic weighing device. Frequently a conveyor belt is designed as a so-called endless belt, i.e. a closed loop, which is guided over at least two conveyor rollers, namely a passive idle roller and a drive roller, which is connected to a drive for actively driving the conveyor belt.
Conventional conveyor belts are constructed as endless belts, which comprise a finger joint, which is welded or glued in such a way that it can no longer be separated. Such a conveyor belt has for example been disclosed in GB 917 260 A. A problem with such a permanently connected endless belt is that in case of having to dismantle the conveyor in order to, for example, change the belt for repair or cleaning purposes, the entire conveying system has to be dismantled. There exists therefore a need for providing a conveyor belt, which can be dismantled in an easy manner.
Commonly known checkweigher systems automatically check a plurality of products for conformity and they separate out defective products, which do not comply with a predefined specification or standard. Check conveyor systems are employed in various environments for performing sorting processes. The sorting process is typically an integral part of the food industry. Sorting is carried out for meat and fish products, for milk products such as cheese, for agricultural products such as nuts etc. The delicate nature of the products which the machines process means that frequent cleaning is required of the components which may come into contact with the product to be processed, such as conveyor belts, vessels for rejects, collecting vessels etc. and indeed of the entire plant. The cross-contact with allergens could increase the risk of contamination by a multiple and thus could represent a serious health risk for the end user of the product.
The main problem with cleaning checkweigher systems consists in the difficulty of gaining optimal access to conveyor belts, reject vessels and collecting vessels. This problem undermines the cleaning efforts of operating personnel considerably and leads to ever growing infestation. In order to perform cleaning the transport belt is relaxed before it can be removed from the belt body of the checkweigher system. The state of the art offers various solutions for replacing the belt of a conveyor belt unit or for bringing it into a position, in which the components can be cleaned.
EP 1 101 715 A1 discloses a belt body with a conveyor belt tensioned around two rollers and resting on a carrier frame. Two clamps attached to the side of the carrier frame secure the hold and positioning of the belt body on the carrier frame. By undoing the clamps the belt body can be completely removed from the carrier frame, so that there is improved access to individual parts for cleaning. The disadvantage is that the components are completely separated from one another, which firstly requires employing more personnel and more depositing surfaces and secondly requires performing personnel to be trained in the correct handling both during dismantling and also during re-assembly.
Another solution is presented in FIG. 8 of JPH 066 099 Y2, according to which the carrier frame can be removed. It can be readily recognized that this gives rise to the same disadvantages as described in the previous paragraph with reference to EP 1 101 715 A1.
In order to improve cleaning of a conveyor belt unit, i.e. in order to gain improved access to hidden parts, the conveyor belt can further be removed. Various solutions in this regard are proposed in the JP 2010 037073 A, KR 2005 00 38 299 A and WO 06 094 417 A1 specifications. The aim of this invention however does not consist in proposing a solution for removing a conveyor belt as such, but to improve access to hidden parts without removing the conveyor belt.
In view of the above mentioned disadvantages the applicant has been looking for a new solution, which makes it possible to develop the conveyor belt unit in such a way as to offer to operating personnel more simplified handling for cleaning the different components of the checkweigher system which come into contact with the product to be processed.
This objective is met by a conveyor belt unit for a dynamic checkweigher, comprising a carrier frame and a belt body connected to the carrier frame and used to convey an object, with conveyor rollers arranged at the ends in transport direction and contrary to the transport direction and a conveyor belt tensioned across the conveyor rollers, wherein the conveyor belt is driven by means of a motor via one of the two conveyor rollers, wherein the conveyor belt unit further comprises a configuration-changing mechanism effective between belt body and carrier frame, which is designed in such a way that, when the configuration-changing mechanism is actuated, the conveyor belt unit switches between a not-ready-to-operate configuration and a ready-to-operate configuration.
According to the invention the configuration-changing mechanism comprises at least one rotating joint element with a thin material bridge, wherein the thin material bridge defines a rotary axis extending essentially parallel to the transport direction.
The advantages of the conveyor belt unit according to the invention for the applicant consist in that the belt body can be swivelled relative to the carrier frame thus offering access to internal parts without having to separate the belt body from the carrier frame.
A conveyor belt unit in terms of this application is understood to refer to not only the feed belt unit and the weighing belt unit but also to the discharge belt unit. In case of the weighing belt unit the conveyor belt unit is supported via a load cell against the base frame of the plant, in case of the feed belt unit and the discharge belt unit these are understood to be mounted directly on the base frame.
Advantageously a rotating joint element may consist of respectively two joint legs which are connected to each other via a thin material bridge. Further a rotating joint element may be attached to the belt body by means of one of the joint legs and to the carrier frame by means of the other of the joint legs, thus enabling the belt body to be swivelled relative to the carrier frame out of the ready-to-operate configuration into the not-ready-to-operate configuration and back.
With one further development the rotating joint element may be attached to the carrier frame in such a way that the defined rotary axis is aligned parallel to the transport direction. Furthermore the rotary axis may be arranged so as to extend above the side element lying on the right-hand side in transport direction or above the side element lying on the left-hand side in transport direction.
Further in another further development the rotating joint element may be attached to the belt body and to the carrier frame in such a way that the defined rotary axis is aligned at right angles to the transport direction. Further, the rotary axis may be arranged so as to lie below the end of the belt body, which extends in transport direction, or below the end of the belt body, which extends contrary to the transport direction.
With one advantageous further development the belt body, in the ready-to-operate configuration, may rest on the carrier frame on support elements arranged opposite the rotating joint element. Further the conveyor belt unit may further comprise a tension lever fixed to the belt body, which may be transferred from a lower snap-in position corresponding to the ready-to-operate configuration into an upper snap-in position corresponding to the not-ready-to-operate configuration, so that the belt body is swivelled during transfer from one snap-in position into the other snap-in position. Further the lower snap-in position and the upper snap-in position may be defined in a matrix, through which the end of the tension lever remote from the belt body reaches.
With another advantageous further development the matrix may be arranged in a side element of the carrier frame, which lies below the support elements or the rotating joint element, or the matrix may be arranged in a cross element of the carrier frame arranged below the support elements or the rotating joint element and connecting the side elements.
In the ready-to-operate configuration of the conveyor belt unit the tension lever may snap under tension into the lower snap-in position thus pressing the belt body against the support elements. In the not-ready-to-operate configuration the tension lever may be supported against the upper snap-in position thus holding the belt body in the swivelled position.
The conveyor belt unit is a feed belt unit or a weighing belt unit or a discharge belt unit.
Details of the conveyor belt unit according to the invention are revealed in the description of the exemplary embodiments shown in the drawings, in which identical parts are identifies with identical part numbers and wherein:
In the combined
In the combined
To switch between the ready-to-operate configuration and the not-ready-to-operate configuration therefore, the tension lever 170 must be changed from the lower snap-in position 182 into the upper snap-in position 184. To this end, the operator merely has, from his point of view, to push the tension lever 170 initially to the right, then upwards and lastly to the left.
The above described invention also comprises various modifications, for example the matrix 180 may of course be designed back-to-front or comprise an intermediate position. Also it is not mandatory for the connecting point 172 of the tension lever 170 to be situated above the side element 114 on the back or, seen in transport direction T, on the left-hand side of the belt body 130, rather it may also be arranged on the front or, seen in transport direction T, on the right-hand side above the side element 112. The inventive solution is not limited to a specific conveyor belt unit, but may be applied both to a feed belt unit, a check weighing unit, a discharge belt unit or any conveyor belt unit present in a product transport section.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20153546.5 | Jan 2020 | EP | regional |
