Abstract:
A connection device connects a driving device and a feeding device and is for use in a scale or combination scale. A connection element has at least one magnet. A receiving device, which is located within the feeding device, includes at least one iron core. The receiving device includes a protrusion, where the receiving device meshes with the connection element in the mounted state for a simple, interlocking, and backlash-free self-centering connection.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
       [0001]    The present application is directed to a connection device, in particular for the use of a connection of a feeding device for a scale and a driving means, in order to transmit the movements of the driving means to the feeding device. 
       2. Discussion of the Related Art 
       [0002]    In particular in the case of scales and combination scales, products to be weighed are distributed by a distribution device and are led to the respective weighing container by feeding devices, which can for example be designed in the shape of a vibration channel, which are forced to vibrate, for example by electromagnetic driving means. For such a use, it is in particular necessary that the feeding devices can be easily dismantled for cleaning purposes and are also easily reinstallable. 
         [0003]    Simultaneously, feeding devices have to be connectable via a stable connection device with the driving device. Hereby, the connection device has to be able to transmit the vibrations, oscillations or other movements generated by the driving device to the feeding device. Simultaneously, it is in particular important for the use in food industry or food processing industry that such a feeding device or the related connection device can be designed hygienically, so that an input or an adhesion of contaminations, e.g. food from a previous processing step, can be avoided, and that an easy and thorough cleanability is possible. 
         [0004]    In the prior art, a connection device for a combination scale is known from EP 0 852 707 B1, in which the movements of a vibration engine are transmitted to a vibration channel via a backlash-free connection. Said connection device has a cylindrical intermediate part, one end thereof being connected with the driving means. The other end of the cylindrical intermediate part is connected to a bottom part via screws, wherein the bottom part can be connected with the bottom side of the vibration channel. By the provision of multiple guide bolts, bores, steps and hubs, the angle position of the vibration channel relative to the distribution device and the weighing containers is variable, so that the feeding of the products can be performed in an optimal way. Furthermore, a clamping element, being adjustable via a clamping lever, is provided, by which the pressing force of the connection element to the bottom part of the distribution device can be adjusted. 
         [0005]    Such a design, however, encompasses significant disadvantages, in particular for plants of the food industry or food processing industry. On the one hand, the connection contains several movable mechanical components. For vibrations obtained by a vibration engine as driving means, the dynamics of such a mechanical system can be hardly predicted. Furthermore, the connection unit according to the mentioned prior art is not designed hygienically, as it contains, caused by bores and bolts, many edges, void spaces and narrow spaces in which food remainders or dirt can easily accumulate, which cannot be removed easily by cleaning, and which can contaminate fresh food by migration via the air or direct contact. This can lead to the fact that food is not durable any more and can even be contaminated or poisoned. A contamination via food remainders can furthermore lead to a disturbance or influence of the dynamics of the connection device. Furthermore, the clamping lever for releasing said connection can only be reached with significant difficulties. In addition, the assembly cannot be sealed because of the complex mechanical system with bolts, bores, steps and hubs. Furthermore, the mentioned clamping lever has to be precisely adjusted during mounting in order to ensure an optimal adjustment of the feeding device. Furthermore, wear can occur on the mounted clamping lever and on members which are connected thereto (e.g. bearings), which leads to decreasing forces up to the complete loss of the interlocking connection. 
         [0006]    Such a member hence encompasses significant disadvantages, in particular for the use in food industry or food processing industry. 
         [0007]    It is hence an objective technical problem of the present application to provide a connection device which solves the above mentioned problems arid in particular leads to a hygienic design. Furthermore, it is an objective technical problem of the present application to provide a connection device with an easy handling, the connection with it being backlash-free. Furthermore, it is an objective technical problem of the present application to provide a connection device for which potential wear at the guiding planes does not lead to a deterioration of the connection. 
       SUMMARY OF THE INVENTION 
       [0008]    Said objective technical problem is solved by a connection device and by a process for the establishing and releasing of a connection of a connection device. 
         [0009]    The present invention contains a connection device which is basically composed of a connection element and a receiving device, wherein the receiving device is coxapled to the feeding device. The feeding device comprises an upper side for feeding of products and an adjacent lower side. The connection element can be coupled with a driving device. Further, the receiving device is designed such that it can receive the upper part of the connection element. The connection element includes at its upper side at least one first magnet, in embodiments also a second magnet. The receiving device basically includes a base, which in turn includes at least one iron core, in embodiments also a second iron core. The base is coupled at least to one protrusion, with which the connection element can be meshed in the coupled state, so that an interlocking connection can be obtained. In the connected state, magnet (s) arid iron core(s) face each other. The connection element and the receiving device are preferentially made of stainless steel with non-ferromagnetic characteristics, preferentially made of austenitic steel. Magnets are preferentially permanent magnets, more preferentially permanent magnets made of neodymium. 
         [0010]    By the use of magnet connections and a suitable geometry of the connection element and the receiving device, an easy mounting and a self-centering of both members is possible. Furthermore, the number of corners, edges, immersions and void spaces can be minimized, so that a hygienic design is possible. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    In the following, a preferred embodiment is further explained with reference to the enclosed figures. 
           [0012]      FIG. 1  shows a feeding device according to a first embodiment, including a receiving device and a connection element. 
           [0013]      FIG. 2  shows the feeding device according to  FIG. 1 , wherein the individual forces, acting at both the magnets and the feeding device, are shown. 
           [0014]      FIG. 3  shows the feeding device according to a first embodiment in a situation in which the receiving device is dismantled from the connection element. Also for this case, the forces during dismantling are presented. 
           [0015]      FIG. 4  shows a feeding device according to a second embodiment, which includes a receiving device, wherein a connection element is in mesh with a projection of the receiving device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]      FIG. 1  shows a connection device  1  according to a first embodiment in a cross-sectional view. A feeding device is labelled with the reference sign  3 , which is a vibration channel in the present embodiment, on which products are deposited and are moved in the direction of a funnel opening  13  on the right side in the FIG., in order to be dropped from there. The connection device  1  is provided at the lower side of the feeding device  3 , approximately in the middle of the longitudinal extension. The connection device  1  basically comprises a receiving device  5  and a connection element  2 . 
         [0017]    In the present embodiment, the receiving device  5  is formed integrally with the feeding device  3 . Alternatively, the connection of the feeding device  3  and the receiving device  5  can be obtained via welding, gluing, etc. The receiving device  5  includes a base  7 , which is formed in a way that it incorporates two iron cores, a first iron core  8  and a second iron core  9 . Both iron cores  8 ,  9  are hence provided inside the base  7 . In the present embodiment, both iron cores  8  and  9  are formed in a disk shape and are incorporated inside the base  7 . The receiving device  5  has a flush, smooth surface without joints, edges, etc., in which contaminations could accumulate. At the outer circumference of the base  7 , a protrusion  6  in the shape of a rib or a wall is connected. The protrusion  6  is formed in a way that it includes an acute angle with the perpendicular line of the surface of the feeding device  3  on the side facing the interior of the base  7 . Thereby, a receiving recess is formed, whose cross-sectional area decreases from the outer edge of the protrusion  6  in a direction towards the base  7  continuously, so that the recess comprises a conical shape tapered to the inside. 
         [0018]    The connection element  2  being in mesh with the receiving device  5  is connected with a driving device (not shown here), for example a vibration engine. It comprises a shape designed in a way that it fits into the receiving device  5  and can be received by it. It has a conical or frustum shape in the upper section, respectively, which basically has a same angle compared to the conical receiving device  5 . A first magnet  10  and a second magnet  11  are integrated into the connection element  2 . Those are, congruently to the iron cores  8 ,  9  in the receiving device  5 , respectively provided within the connection element  2 , i.e. for example integrated into respective recesses, glued or even infused. The recesses can be closed with a cap, which is welded with the surface of the connection element  2 . Hence, recesses, notches, gaps or the like are avoided here, in which contaminations could accumulate. 
         [0019]    The dimensions of the receiving device  5  and the connection element  2  are designed in a way that a small air gap L between the adjacent surfaces is obtained in the connected state, and that both conical outer walls or inner walls are in contact with each other. Beyond said fact, the following advantage can be achieved: Even if a contamination should be present on one of both surfaces once, a perfect positioning and a close contact can be ensured, as said contamination finds room in the provided gap. Even if insufficient cleaning is performed, the function can still be ensured despite contaminations which are not completely removed. By the simple connection of the receiving device  5  and the connection element  2 , the feeding device  3  can be easily dismantled and subjected to cleaning, whereby clean members can be used all the time. 
         [0020]    The connection device  1  is shown in the mounted state in  FIG. 1 , i.e. the connection element  2  is in mesh with the protrusion  6  of the receiving device  5 . Hence, the first magnet  10  of the connection element  2  faces the first iron core  8  of the receiving device  5 , and the second magnet  11  of the connection element  2  faces the second iron core  9  of the receiving device  5 . Furthermore, the formation of an air gap L between the upper side  2   a  of the connection element  2  and the receiving device  5  is enabled by the alignment of the protrusion  6  in an acute angle to the perpendicular line of the surface of the feeding device  3  and the frustum-like or conical shape of the connection element  2 . By this air gap L, space for potentially occurring accumulations can be created, which would not prevent a clean, interlocking connection in this case. 
         [0021]      FIG. 2  basically corresponds to  FIG. 1 . In  FIG. 2 , however, the forces are presented which act on individual points of the feeding device  3 : at the center of gravity of the feeding device  3 , the weight force F S  acts in negative y-direction, wherein both reaction forces F 1  and F 2  act on the first magnet  10  and the second magnet  11  in positive y-direction by both iron cores  8  and  9 . 
         [0022]    During operation of the feeding device  3 , the weight force Fs of the feeding device  3  is not constant, as the feeding device  3  can be impinged, in addition to its own weight, with the weight force of products which have their own mass. As said products still move, also the position of the center of gravity of the whole system of feeding device  3  and products constantly changes. Hence, the resulting reaction forces F 1  and F 2  respectively depend on the weight force F S  and the distances of the forces F 1 , F 2  and F S  from the rotation point D. Counter-forces to the reaction forces F 1  and F 2  are the holding force F 1 ′ and F 2 ′ caused by the magnets. 
         [0023]    Herein, the magnetic forces of the first magnet  10  and the second magnet  11  are selected in a way that they can respectively cause a higher holding force F 1 ′ and F 2 ′ compared to the respective reaction forces F 1  and F 2.    
         [0024]    As visible in  FIG. 2 , the magnets  10 ,  11  are positioned in a way that a first holding moment M 1 ′ obtained by the first holding force F 1 ′ and the lever arm l 1  is greater than a second holding moment M 2 ′ obtained by the second holding force F 2 ′ and the lever arm l 2 , what can be caused even for assumed theroretically equal holding forces F 1 ′, F 2 ′ only by different distances ( 1   1 , l 2 ) from the rotation point D. 
         [0025]    As the magnetic force of the first magnet  10  is further selected to be greater than the magnetic force of the second magnet  11 , the first holding moment M 1 ′ is thereby enlarging compared to the second holding moment M 2 ′. It has to be noted in this case that the magnetic forces decrease because of the air gap L, more precisely square proportional with the distance between magnets  10 ,  11  and iron cores  8 ,  9 ; i.e. said distance has to be kept small. 
         [0026]    By the selection of the magnetic forces, it can be ensured that a detachment of the receiving device  5  from the connection element  2  can be safely prevented because of the holding forces F 1 ′ and F 2 ′ caused by the magnets, which are greater than the maximally possible reaction forces F 1  and F 2 . The longer lever arm lx of the magnetic force of the first magnet  10  significantly contributes to the generation of a respective holding moment M 1 . 
         [0027]    As the center of gravity of the connection element  2  including the supplied mass can be outside of the receiving device  5 , a potential tilting moment (in  FIG. 2  clockwisely) can be avoided by the holding moments M 1 ′ and M 2 ′ (in  FIG. 2  counter-clockwisely), which are generated by the magnetic forces of the first magnet  10  (F 1 ′) and the second magnet  11  (F 2 ′). 
         [0028]      FIG. 3  shows a connection device  1  during dismantling, i.e. while the feeding device  3  is detached from the connection element  2 . Compared to  FIG. 2 , the forces generated by the magnets and the resulting moments (F 1 ′ and M 1 ′ at the first magnet  10 , F 2 ′ and M 2 ′ at the second magnet  11 ) are basically equal, before the feeding device  3  begins to move away from the connection element  2 . The weight force F S  of the feeding device  3  counter-acts a detachment force F h , which is applied to a point H of the feeding device  3 , in  FIG. 3  at the right lower end. The rotation point for the detachment of the feeding device  3  is now at the position D′, The application of the force F h  at the right end of the feeding device generates, caused by its longer lever arm l h , a great detaching moment M h  around the rotation point D′. The counter-acting holding moments M 1  and M 2  of the magnetic holding forces F 1 ′ (deriving from the first magnet  10 ) and F 2 ′ (deriving from the second magnet  11 ) have, however, only small lever arms l 1  and l 2 . Herein, the greater one of both forces, F 1 , has the smallest lever arm l 1 . The detachment of the connected elements can be performed very easily in this way, as the greatest holding force F 1 ′ (caused by the greatest magnetic force) generates the smallest moment M 1 . After beginning of the detachment, the forces F 1 ′ and F 2 ′ , deriving from the magnets  10 ,  11 , decrease because of the continuously increasing gap between the magnets  10 ,  11  and iron cores  8 ,  9 , thereby also continuously decreasing the holding moments M 1 ′ and M 2 ′. 
         [0029]    In the following, the process for establishing and detaching the connection of the connection element  2  and the receiving device  5  shall be described. 
         [0030]    For establishing the connection, the connection element  2  is brought with its upper side  2   a  into direct proximity of the receiving device  5 , so that the first iron core  8  of the receiving device  5  and the first magnet  10  of the connection element  2 , and the second iron core  9  of the receiving device  5  and the second magnet  11  of the connection element  2  face each other, so that magnetic attraction forces are established and can act. The resulting magnetic forces cause that the connection element  2  approaches the receiving device  5  and is meshed within the protrxasion  6  of the receiving device  5  in a self-centering way. The distance between the receiving device  5  and the connection element  2  decreases continuously, until the connection element  2  has reached its final position within the receiving device  5 . In this final position, only the narrow air gap L is present between the receiving device  5  and the connection element  2 . 
         [0031]    For detaching of the connection, a pressing force F h  is applied to a point (point H in  FIG. 3 ) of the feeding device  3 , which has a larger distance from the first iron core  8  than from the second iron core  9 . The point H, to which the force for detaching F h  is applied, is different from the center of gravity of the feeding device  3  in  FIG. 3 . By the resulting rotation moments, the holding force F 2 ′ is overcome first, and then, the distance between connection element  2  and receiving device  5  begins increasing in the area in which the second iron core  9  and the second magnet  11  are provided. Only when further rotation around the rotation point D′ is performed, also the distance between areas, in which the first magnet  10  in the connection element  2  and the first iron core  8  in the receiving device  5  are provided, begins to increase, when also the holding force F 1 ′ is overcome. The frustum shape of the connection element  2  and the arrangement of the protrusion  6  in an acute angle with the perpendicular line of the surface of the feeding device  3  hence allow a rotation around the rotation point D′. 
         [0032]      FIG. 4  shows a second embodiment of the invention. Contrary to the first embodiment, the receiving device  5  is not integrally formed with the feeding device  3  and is not welded to it, but is connected to it via two holding devices  12 . Hence, the receiving device  5  is provided with a distance to the feeding device  3 . 
         [0033]    The feeding device  3  furthermore has no rotationally symmetric shape, but is formed in an oval shape. 
         [0034]    Furthermore, the connection element  2  has hollow sections in the inside and is not formed in a continuously massive manner. 
       Further Embodiments 
       [0035]    The present invention is not limited to the above-mentioned embodiment. 
         [0036]    For example, further geometries of the connection element  2  are possible. This does not have to be necessarily formed in a rotationally symmetric or oval shape. Also, polygonal shapes are possible, e.g. square or rectangular, or composite shapes. 
         [0037]    Furthermore, there are further possibilities for the design of the protrusion  6 , wherein, however, the protrusion  6  always has to be in mesh with the connection element  2  and no press fit must be present, in order to enable a rotation around the rotation point D′. 
         [0038]    Furthermore, it is not necessary to design the protrusion  6  continuously. Multiple partial protrusions with distances therebetween are also possible. 
         [0039]    Furthermore, it is also possible to provide the first magnet  10  and/or the second magnet  11  not as permanent magnets, but as electromagnets. In this case, electrical lines for the supply of both magnets would have to be provided through the connection element  2 . For this purpose, a respective bore would have to be provided. 
         [0040]    Furthermore, it is not necessary to provide the iron cores  8  and  9  within the connection element  2 . A variation is also possible, for which in turn both magnets  10 ,  11  are provided on the Tapper side  2   a  of the connection element  2 . Furthermore, it is possible that both iron cores  8 ,  9  are not provided within the base  7  of the feeding device  3 , but would be mounted at the lower surface of the base  7 . 
         [0041]    Furthermore, it is also possible to provide the iron cores  8 ,  9  on the connection element  2  and to provide both magnets  10 ,  11  on the receiving device  5 . 
         [0042]    Furthermore, the invention is not limited to exactly two magnets. It is also possible to provide more than two magnets, wherein in the latter case, it has to be regarded that individual magnets which have a larger distance from the center of gravity of the feeding device  3 , need to have a greater magnetic force compared to those magnets which are provided closer to the center of gravity of the feeding device  3 . 
         [0043]    Furthermore, a solution with only one magnet and/or one iron core is possible. Herein, at least one selected from magnet and iron core has to be shaped in a way that the magnetic force decreases with increasing distance from the rotation point (D′). This can, for example, be achieved by a respective shape of the magnet and/or iron core (for example in the shape of the segment of a circle). Also in this way, the connection element  2  and the receiving device  5  are formed in a way that they can be detached from each other by tilting around the rotation point (D′). 
         [0044]    Depending on the shape of the connection element  2  and the protrusion  6 , respective rotation axes can be present instead of the rotation points D and D′.