Patent Publication Number: US-2010109823-A1

Title: Magnetic storage switch

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of PCT International Patent Application Serial No. PCT/DE2007/000085, filed Jan. 28, 2007, designating the United States. Priority is also claimed from German Application Serial No. 10 2006 002 757.4 filed Jan. 20, 2006. 
    
    
     FIELD OF THE INVENTION 
     The following invention is directed to a magnetic storage switch and especially a magnetic storage switch for use in medium voltage installations. 
     It is one object to provide a switch, which is able to execute switching proceedings at a very high speed. This object is achieved by the object of the independent claims. Advantageous embodiments are described in the subclaims. 
     SUMMARY OF THE INVENTION 
     A magnetic storage switch according to the invention comprises a pole armature which can be rotated about an axis, a first switch disc and a second switch disc, wherein the pole armature is provided between these switch discs and the pole armature comprises a plurality of magnets which are arranged with respectively alternating polarity in the circumferential direction of the pole armature. According to the invention the switch discs comprise magnetizable ring segments in the form of magnetic sheets and the two switch discs are rotated relative to one another by approximately one half of the pitch with respect to the ring segments. 
     A rotation of the pole armature effectuates, that one of the two switch discs is magnetized while the other one short circuits the magnetic flow. In this manner magnetizable elements on either side of the pole armature or the two switch discs can be attracted in dependence of the rotational position of the pole armature. 
     In a preferred embodiment of the invention two switch plates are provided, wherein the switch discs and the pole armature are provided between these switch plates. These switch plates can be used as the above mentioned magnetizable elements, which are attracted in dependence of the rotational position of the pole armature. Preferably the two switch plates are constructed in a identical manner. In this way a symmetric switching can be provided. 
     In a further preferred embodiment the switch plates can move relative to the switch discs in the direction of the rotation axis of the pole armature. Very preferably the movement of one switch plate is coupled to a movement of the other switch plate. 
     In a further preferred embodiment return springs are provided which pretension the switch plates. In this way a lose movement of the switch plates can be avoided. Also the switch plates can be forced to a predefined position, ie—an equilibrium position with respect to the switch discs. The return springs may comprise identical or also different spring forces respectively spring constants. Both pressure springs and tension springs may be used. 
     The invention is furthermore directed to a magnetic storage switch with a pole armature, which can move in a longitudinal direction, with a first switch disc and a second switch disc, wherein the pole armature is provided between these switch discs and wherein the pole armature comprises a plurality of magnets which are arranged next to one another with respectively alternating polarity in the longitudinal direction of the pole armature. According to the invention the switch discs comprise magnetisable segments and the two switch discs are displaced relative to one another in the longitudinal direction by approximately one half of the pitch with respect to the segments. 
     Whereas the above mentioned embodiment is characterised by a rotational movement of the pole armature, in this case the pole armature is moved along a longitudinal path and preferably a linear path. By virtue of the displacement of the two switch discs with respect to each other also in this case one of the switch discs is magnetised whereas the other one short-circuits the magnetic flow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages and embodiments of the invention are disclosed in the accompanying drawing. Therein show: 
         FIG. 1  a schematic view of a first embodiment of the invention; 
         FIG. 2  a schematic view of a second embodiment of the invention; 
         FIGS. 3   a - 3   d  a schematic view of a first embodiment according to the invention; and 
         FIG. 4  a characteristic curve of the magnetic flow. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIGS. 3   a - 3   c  show a schematic view of a magnetic storage switch according to the invention. This magnetic storage switch comprises a pole armature  2  (see  FIG. 3   a ), which is rotatable supported around an outer bushing  8  with bearings  14 . The pole armature  2  comprises a plurality of permanent magnets  3  with alternating alignment. In the case shown in  FIG. 3   c  the pole armature  2  comprises  12  permanent magnets. 
     Reference numeral  4  (in the figures also reference symbol A is used) denotes a first switch disc, which is located adjacent to pole armature  3 . Another switch disc  6  (also denoted with B in the figures) is located at the other side of the pole armature  3 . These switch discs  4  and  6  are located fixed in rotation with respect to the outer bushing  8 . Reference numeral  9  denotes another bushing, which is arranged in the interior of the outer bushing  8  and which is movable along arrow P. Reference numeral denotes an axle. 
     Fixed with respect to this bushing  9  two switch plates  11 ,  12  are arranged. In dependence of a rotational position of the pole armature either the left switch plate  12  or the right switch plate  12  will me attracted by the pole armature  2  and drawn in the direction of the pole armature  2 . 
     Reference numeral  5  denotes a lever, which is fixedly arranged at the pole armature  3 . With this lever the pole armature can be rotated by a certain angle, for example  5  degrees, which leads to a switching of the switch. 
       FIG. 3   b  shows a top view of a switch disc  4 . This switch disc  12  comprises a plurality of ring segments  26 , formed of a magnet sheet. Between two ring segments  26  a plurality of bridges  28  is arranged, wherein these bridges are formed of for example copper. The cross section of the sectors  26  corresponds essentially to the cross section of the permanent magnets  3 . In generally, the bridges  28  are formed of a non magnetizable material. Other suitable materials would be glass, plastic, PUR, wood and the like. Also, a carrier could be provided, which separates the ring segments from each other. In this case, there would be a space between the ring segments  26 . 
     The two switch discs  4 ,  6  shown in  FIG. 3   a  are rotated relative to one another by approximately one half of the pitch with respect to the ring segments  26 . 
     In dependence of a rotational position of the pole armature  2  with respect to the ring segments  26  one of the switch plates  11 ,  12  will be attracted stronger by the pole armature  2  than the other. 
     If for example each ring segment  26  of a switch disc  4  covers the permanent magnet  3 , respectively its cross section, the magnetic force of the permanent magnets will be transferred to the ring segment  26  of the switch disc. 
     In this case the bridge  28  made from copper or another non magnetisable material will not influence the magnetic force. This results in an attraction of the respective switch plate  12  by the switch disc  4 . 
     In  FIGS. 3   a - 3   c  the pole armature has a full cylindrically shape. However the shape of the pole armature may also be a partly cylindrically shape. 
     If on the other hand, the permanent magnets  3  are between two ring segments  26 , a short circuit will appear (i.e. the ring segment  26  will short circuit the magnetic flow) and the respective switch plate will not be attracted by the pole armature. The switch plates  11 ,  12  may comprise contacting elements (not shown) which in dependence of the position of the switch plates open or close an electric circuit. It is also possible to use the magnetic switch according to the invention to switch other mechanical elements. 
     Preferably, the pitch of the ring segments  26  equals the pitch of the magnets  3 . However, the width of the ring segments  26  in the circumferential direction may also be greater or smaller and especially smaller than that of the magnets  3 . 
       FIG. 2  shows another embodiment of the switch according to the invention. In this case a pole armature is provided, which is movable along a longitudinal path as indicated by the arrow. The switch discs are located on either side of the pole armature. Also, the switch discs A,B are displaced relative to one another in the longitudinal direction by approximately one half of the pitch with respect to the segments. As indicated both in  FIG. 1  and in  FIG. 2 , a elastic spring is provided, which is preferably adjustable and serves to reset the switch plates. Also in the embodiment shown in  FIGS. 3   a - 3   d  a respective spring may be provided. In  FIG. 1  the switch plates, which are fixedly coupled to the bushing  8  respectively the axle shown in  FIG. 1 , are not shown. 
     As illustrated in  FIG. 3   d , only below a distance of 4 mm a usable magnetic force will arise, which will be transferred in an “abundant” attraction force for distances below  2  mm (between the switch discs and the switch plates). This abundant energy is stored in a spring and is used for reducing the activation force (i.e. the rotation of the pole armature). Otherwise for switching the magnet attraction direction in each case the full reminiscence energy would be needed. To reduce the dissipation loss, one part can be saved by storing the energy in springs. 
     The elastic springs force the switch plates  11 ,  12  (see  FIG. 1 ) into an equilibrium state or into a position, in which the distance between switch plate  11  and the switch disc  6  essentially equals the distance between the switch plate  12  and the switch disc  4 . As mentioned above, the magnetic force will not be sufficient to attract the switch plates at a distance greater than about 4 mm. For certain applications, this distance might not be sufficient. 
     However, by virtue of this springs, as mentioned above, the distance between the switch discs  4 ,  6  and the switch plates  11 ,  12  can be increased, since the springs will force the switch plates back to certain distance. If for example the distance between the two switch plates  11 ,  12  is 6 mm greater than the distance between the switch discs  4  and  6 , the springs can be adjusted to force the switch plates into a symmetrical position with respect to the switch discs. In this case the distance between the switch discs and the switch plates is 3 mm respectively and therefore low enough for magnetic attraction to appear. 
     With the next switching the force stored in the reset spring adds to the attraction force at a distance of 4 mm or less. 
       FIG. 4  shows a characteristic curve of the magnetic force in relation to the distance of two elements i.e. A switch disc (A and B) and a switch plate. As can be seen, the magnetic force increases disproportionately for decreasing distances between the switch discs and the respective switch plates. The force of a spring in contrast increases linearly with increasing distance between the switch plates and the switch discs from a certain equilibrium point. Therefore, the magnetic force, which appears at very short distances between the switch plates and the switch discs, is stronger than the elastic force of the spring elements and can therefore partly be saved in the spring element. 
     Using the lever principle, in switch position A ( FIG. 1 ), the switch lever is displaced from position C to position D, aided by the force F A/B . Once in position D, the magnetic poles in A are short-circuited and in B are released. The magnetic field in B builds up and attracts the switch plate B. At the same time, the lever passes from G to H and in the process prestresses the spring again for the auxiliary force F NB  via the magnetic attraction peak in phase c. 
     Intended use: e.g. as a switch drive in medium-voltage installations. 
     The intention is to protect the functional principle of a magnetic storage switch
     1. characterised by magnetic pole rotation for pole short-circuiting and thus for changing the magnetic attraction direction from switch position A to B and vice versa. see  FIGS. 1-4     2. characterised in that the switch discs part  2  (A, B) are rotated relative to one another by approximately one half of the pitch.   3. characterised by the rotary arrangement and functional principle (see  FIG. 1 ), but also by the translatory arrangement ( FIG. 2 ) and the functional principle thereof for displacing the magnetic poles relative to one another, for switching purposes.   4. but also characterised by a translatory arrangement in which the switch faces are displaced relative to one another by approximately one half of the pitch.   5. characterised by the shifting of the magnetic attraction peaks ( FIG. 4 ) from phase c to phase a in general, and in particular the shifting of the magnetic force peaks via said lever principle.   

     KEY TO FIGURES 
       
     
       
         
           
               
               
             
               
                   
               
               
                 GERMAN 
                 ENGLISH 
               
               
                   
               
             
            
               
                 Magnetspeicherschalter 
                 Magnetic storage switch 
               
               
                 Feder F A/B  einstellbar 
                 Spring F A/B , adjustable 
               
               
                 Rückholfeder, einstellbar 
                 Return spring, adjustable 
               
               
                 Magneteblock auf Schienen 
                 Magnet block guided on rails 
               
               
                 geführt 
               
               
                 Magnetanzugskraft 
                 Magnetic attraction force 
               
               
                 Abstand zur Schaltplatte 
                 Distance from switch plate 
               
               
                 Kupfer 
                 Copper 
               
               
                 Magnetblech 
                 Magnetic sheet 
               
               
                 Hartlot 
                 Hard solder 
               
               
                 Weichlot 
                 Soft solder 
               
               
                 Kupferhülse 
                 Copper sleeve 
               
               
                 Teil 2 = Schaltplatte 
                 Part 2 = switch plate 
               
               
                 Teil 1 
                 Part 1 
               
               
                 Schaltstellung 
                 Switch position 
               
               
                 Schaltnippel zur Verdrehung 
                 Switch nipple for rotating the pole 
               
               
                 des Polankers um ca. 5° und damit 
                 armature by approx. 5° and thus for 
               
               
                 zur Schaltauslösung A-B 
                 triggering the switch A-B 
               
               
                 Dauermagnetkreisringsegmente 
                 Permanent magnet ring segments 
               
               
                 Trennstreifen aus Nicht- 
                 Separating strips of non-magnetic 
               
               
                 magnet-Metall 
                 metal 
               
               
                 Kennlinie: 
                 Curve: 
               
               
                 Verlagerung von Magnetkraft 
                 Shift of magnetic force in phase c to 
               
               
                 in Phase c nach Phase a 
                 phase a 
               
               
                 für Schaltstellung 
                 for switch position