Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 USC 119(e) of U.S. Application No. 61/091,913 filed Aug. 26, 2008, the entirety of which is incorporated by reference herein. 
    
    
     BACKGROUND 
     Field 
     The present invention relates to a device for the torque limitation in a machine for processing means of payment. 
     In the following means of payment shall mean bank notes, checks, vouchers, coupons and coins. Processing means of payment shall mean the automatic processing of means of payment for example with bank note processing machines, coin processing machines etc, which are operated by operators in order to, in particular, check, count and account the means of payment. 
     With the automatic processing of means of payment, for example, certain quantities of means of payment are handed in by depositors to an authority effecting the automatic processing, e.g. a bank, in order to be accounted, so that the total value of the means of payment can be credited e.g. to a bank account of the depositor. 
     Here it can occur that the operator or the depositor comes in contact with moving parts of the machine effecting the automatic processing, the result of which can be a risk of injury for the operator. 
     Likewise, a damage of the machine effecting the automatic processing of the means of payment can occur. It can occur, for example, that foreign objects are between the bank notes inputted by the operator, which are thicker and harder than the bank notes and during the processing, e.g. singling of the bank notes, would lead to a damage of the machine effecting the automatic processing of the means of payment. 
     Further damage of the machine effecting the automatic processing of the means of payment can occur, when components of the machine inserted by the operator into the machine, e.g. cassettes for receiving means of payment, are not properly inserted into the machine. 
     All the cases described by way of example have in common, that too high torques can cause injuries of the operator or damage of the machine effecting the automatic processing of the means of payment, in particular of a drive of the machine. 
     SUMMARY 
     Therefore, it is the object of the present invention to provide a device for the torque limitation in a machine for processing means of payment, which has an especially simple structure and permits a reliable limitation of torques. 
     This object is achieved according to the invention by the features of the independent claim. 
     The invention starts out from a device for the torque limitation in a machine for processing means of payment, the device for the torque limitation having two elements transmitting a torque, the two elements having magnets which are disposed in the two elements with an angular distribution of the same kind, the magnets connecting the two elements to each other in a non-positive fashion, and the connection of the two elements being disrupted, when a maximum of transmittable torque is exceeded. 
     The advantage of the invention in particular is that with the help of the two elements a safety coupling especially simple to realize can be realized, which has an exactly defined maximum transmittable torque. Moreover, the device works wear-free with magnetic forces. 
     In an advantageous development it is provided, that the two elements of the device have depressions and elevations, which are disposed on the adjacent surfaces of the two elements with an angular distribution of the same kind, in particular with cylindrical depressions and spherical elevations. 
     The advantageous development has the advantage, that the maximum torque transmittable by the device can be easily increased, without there having to be made especially high demands on the magnetic forces of the magnets used in the elements. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Further advantages of the present invention appear from the dependent claims as well as the following description of an embodiment with reference to Figures. 
         FIG. 1  shows an embodiment of a device for the torque limitation in a machine for processing means of payment on transmitting a torque, and 
         FIGS. 2 and 3  show substantial component parts of the device shown in  FIG. 1 . 
         FIG. 4  shows a schematic view of a machine for processing payment means. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In  FIG. 1  is shown an embodiment of a device for the torque limitation in a machine for processing means of payment on transmitting a torque. In the shown embodiment a torque of a drive or a motor  16  is transmitted with the help of a shaft  10 ,  20  consisting of two parts to a toothed wheel  21  which e.g. with the help of a toothed belt drives parts of the machine for processing means of payment. For example, as shown in  FIG. 4 , the device for torque limitation may used in a machine  100  for processing means of payment in combination with a singler  101  or a mechanism  201  disposed in a cassette  200  for receiving means of payment, e.g. for receiving bank notes BN in a singler  101 , and transporting the bank notes on path  202  and stacking the bank notes BN in the cassette  200 . Between the two shaft parts  10 ,  20  there are disposed two elements  12 ,  22  for limiting the transmitted torque, which form a safety coupling. The two elements  12 ,  22  can be formed in a disk-shaped fashion. Each of the two elements  12 ,  22  is firmly connected with one end of the two shaft parts  10 ,  20 . For monitoring a rotational speed that has to be observed when operating the shaft  10 ,  20 , a clocking disk  11  can be provided, which is firmly connected with the shaft. With the help of a not shown forked light barrier, which is disposed in the rotating area of the clocking disk  11  the rotational speed of the shaft can be determined by evaluating the output signal of the forked light barrier. 
       FIGS. 2 and 3  show the shaft  10 ,  20  consisting of two parts in a separated state. Here the surfaces of the element  12 ,  22  forming the safety coupling, that adjoin each other when transmitting a torque, become visible. The first element  12  mounted at the first shaft part  10  has magnets  13 . Additionally, the first element  12  can have depressions  14 , which can be formed e.g. cylindrical. Moreover, the first shaft part  10  can have a tapered extension  15 , which protrudes beyond the surface of the first element  12 . The second element  22  mounted at the second shaft part  20  has magnets  23 . Additionally, the second element  22  can have elevations  24 , which can be formed e.g. as spheres. Moreover, the second shaft part  20  can have a bush-shaped bore  25 . 
     When first and second shaft part  10 ,  20 , as shown in  FIG. 1 , are brought together, the extension  15  of the first shaft part  10  moves into engagement with the bush  25  of the second shaft part  20 . The magnets  13  of the first element  12  and the magnets  23  of the second element  22  attract each other and connect the first element  12  and the second element  22  with each other in a non-positive fashion, so that their surfaces adjoin each other. It is obvious, that the pole direction of the magnets  13  and  23  must be chosen such that the magnets  13  of the first element  12  and the magnets  23  of the second element  22  attract each other. For example, the magnets  13  of the first element  12  are inserted such that they have a north pole at the surface of the first element  12 , whereas the magnets  23  of the second element  22  are inserted such that they have a south pole at the surface of the second element  22 . In the shown example with four magnets per element, then first and second element are connected with each other after a quarter turn at the latest. But it is also possible, that in both elements for example a north pole follows a south pole. In the shown example with four magnets per element, then first and second element are connected with each other after a half turn at the latest. 
     By choosing number, type and size of the magnets  13 ,  23  and the size, i.e. the diameter, of the elements  12 ,  22  of the device for the torque limitation, or the distance between the magnets  13 ,  23  and the axial center of the shaft  10 ,  20 , there can be determined the maximum transmittable torque. If, for example, a diameter of 20 millimeters is chosen for the elements  12 ,  22  and if four permanent magnets of the REFeB type with a degree of magnetization N52 and 5 millimeters diameter at a length of 6 millimeters are chosen and disposed concentric to the axis of the shaft  10 ,  20 , a maximum torque of 0.18 Nm can be transmitted. 
     When bringing together the first and second element  12 ,  22 , moreover, the possibly additionally provided elevations  24  of the second element  22 , which e.g. are formed as spheres, move into engagement with the possibly additionally provided, for example, cylindrical depressions  14  of the first element  12 . In this way first and second element  12 ,  22  can be positively connected, when viewed in the direction of rotation. With that the torque transmittable by the device for the torque limitation can be increased. The effect of the elevations  24  and depressions  14 , which increases the maximum transmittable torque, substantially depends on their dimensions, in particular on the height and depth of the elevations  24  and depressions  14 , respectively, and their form. Instead of providing the elevations and depressions each on one of the elements, elevations and depressions can be alternately provided on the two elements. 
     When the torque transmitted by the shaft  10 ,  20  exceeds the maximum permissible value, e.g. because the singler for bank notes is blocked by foreign objects, the retention forces of the magnets  13 ,  23  are exceeded and the device for the torque limitation effects a disruption of the shaft  10 ,  20  between first and second element  12 ,  22 . When, optionally, the above-described depressions  14  and elevations  24  are provided, the transmittable torque is increased respectively, so that for achieving the desired torque lower magnetic forces are sufficient. 
     When the cause, that effects the exceeding of the maximum torque, is eliminated, first and second shaft part  10 ,  20  are re-connected with each other with the help of first and second element  12 ,  22  as described above, so that a torque can be transmitted until the maximum permissible torque. Here the elements  12 ,  22  and thus the shaft parts  10 ,  20  are put together again and held together by the magnetic forces of the magnets  13 ,  23  used. 
     In particular when the described depressions  14  and elevations  24  in the surfaces of the elements  12 ,  22  are used, it can be provided, that one of the elements  12 ,  22  is mounted movable in axial direction on the respective shaft part  10 ,  20 . This permits that in the case the maximum transmittable torque is exceeded the movably mounted element  12 ,  22  can evade. The permissible axial movability here can approximately correspond to the height of the elevations  24 . 
     In the described embodiment first and second element  12 ,  22  of the device for the torque limitation each have four magnets  13 ,  23 . It is obvious, that more or less than four magnets per element  12 ,  22  can be used. Here it is required, that the magnets  13  of the first element  12  and the magnets  23  of the second element  22  have an angular distribution of the same kind. The same applies for the optionally provided four elevations  24  or depressions  14  per element  22  or  12 . 
     As shown, elements  12 ,  22  are formed in a disk-shaped fashion, but it is obvious, that the elements  12 ,  22  can also have a different form, in order to in particular accommodate the magnets  13 ,  23 . 
     From the Figures and the description of the action principle of the device for the torque limitation it obviously appears, that the device for the torque limitation is suitable to effect a torque limitation in both directions of rotation. 
     Likewise, from the Figures and their description results that the two shaft parts  10 ,  20  are separable. For example, the second shaft part  20  can be component part of a cassette, the first shaft part  10  can be disposed in the machine for processing means of payment. Thus the cassette and with that the second shaft part  20  can be easily flanged to the machine for processing means of payment and thus to the first shaft part  10 , to permit the driving of the elements located in the cassette.

Technology Category: 4