Patent Publication Number: US-6661319-B2

Title: Bounce-reduced relay

Description:
This application claims Paris Convention Priority of DE 101 62 585.5 filed Dec. 19, 2001, the complete disclosure of which is hereby incorporated reference. 
     BACKGROUND OF THE INVENTION 
     The invention concerns a relay comprising a contact spring which closes or interrupts the electric circuit between a first and a second relay contact, one end of the contact spring being conductively connected to the first relay contact and its other free end closing or interrupting the electric circuit in a first end position of the contact spring and in a second end position of the contact spring, respectively; an armature which can be adjusted by a reversible magnetic field for deflecting the contact spring into the respective end position; and an additional spring biasing the contact spring into the first end position. 
     A relay of this type is known e.g. from DE 93 20 696 U1. 
     In this known relay, an electric circuit between two electric relay contacts is closed or interrupted by a contact spring. The contact spring is connected to a permanent magnet of an H-type armature via a displaceable actuator, the permanent magnet being pivotably disposed on two yoke legs of a magnet coil. When the poles of the magnet coil are reversed, the permanent magnet is pivoted thereby displacing the actuator. Since the actuator engages behind the contact spring, the contact spring is deflected from its closed rest position such that the electric circuit is interrupted. The free end of the contact spring is biased towards the closed end position through a leaf spring which is mounted on the side of the housing and acts on an actuating button of the contact spring. 
     It is the object of the invention to bias the contact spring of a relay of the above-mentioned type in a different fashion in the direction towards the closed end position. 
     SUMMARY OF THE INVENTION 
     This object is achieved in accordance with the invention in that the additional spring is supported, at least in the first end position, on the armature or on an actuator of the armature. 
     The advantage obtained by the invention consists in bounce-reduced switching of the relay into the closed relay position since the additional spring counteracts deflection of the contact spring in the opening direction when the relay is in the closed position. 
     The additional spring is mounted to the armature or to the actuator of the armature or in particularly preferred embodiments of the invention to the contact spring, in particular to its free end. 
     The additional spring is preferably a flat or leaf spring from electrically conducting material such as e.g. steel, beryllium, Cu-alloys etc. 
     In one variant of the invention, the free end of the additional spring is directed towards the free end of the contact spring. The free end of the additional spring preferably projects past the free end of the contact spring. 
     In other variants of the invention, the free end of the additional spring can also project laterally past the contact spring or be directed away from the free end of the contact spring. 
     The actuator is preferably disposed such that it can be linearly displaced approximately in the deflecting direction of the contact spring and is motionally coupled to the free end of the contact spring. 
     In preferred embodiments of the invention, the contact spring is directly coupled with the armature or the actuator of the armature in the opening direction of the relay, and is motionally coupled thereto in the closing direction of the relay via the additional spring. In one variant, the actuator engages behind the free end of the contact spring and carries along the contact spring in the opening direction. 
     In a preferred embodiment of the invention, the actuator is directly hinged to the armature and therewith directly motionally coupled to the armature. The pressure of the contact spring on the second relay contact is provided by the pressure force of the compressed additional spring. 
     In another preferred embodiment of the invention, the actuator is motionally coupled with the armature by means of a coupling spring acting therebetween. The pressure of the contact spring on the second relay contact is provided by the pressure of the compressed additional spring and the compressed coupling spring. 
     Further advantages of the invention can be extracted from the description and the drawing. The features mentioned above and below can be utilized in accordance with the invention either individually or collectively in any arbitrary combination. The embodiments shown and described are not to be understood as exhaustive enumeration but rather have exemplary character for describing the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows an interior view of the inventive relay in the closed relay position in which a contact spring closes the electric circuit between two relay contacts, with removed cover; 
     FIG. 2 shows the relay of FIG. 1 in the open relay position in which the contact spring interrupts the electric circuit between the two relay contacts; 
     FIG. 3 shows an additional spring of the relay of FIGS. 1 and 2 disposed on the contact spring; 
     FIG. 4 shows an arrangement variant of the additional spring in a representation analog to FIG. 3; 
     FIG. 5 shows another arrangement variant of the additional spring in a representation analog to FIG. 3; 
     FIG. 6 shows a second embodiment of the inventive relay in the closed relay position; and 
     FIG. 7 shows the relay of FIG. 6 in the opened relay position. 
    
    
     DETAILED DESCRIPTION 
     The relay  1  shown in FIGS. 1 and 2 comprises two relay contacts  2 ,  3  and a contact spring  4  which closes or interrupts the electric circuit between the two relay contacts  2 ,  3  and is formed as electrically conducting leaf or flat spring. One end of the contact spring  4  is mounted in an electrically conducting fashion to the first relay contact  2  while the other free end  5  bears a contact button  6  and can be deflected by means of a magnetic drive  7 . The contact spring  4  is deflected to the bottom in the closed relay position shown in FIG. 1 such that the contact button  6  abuts the second relay contact  3  and is deflected in the open relay position shown in FIG. 2 such that the contact button  6  is lifted from the second relay contact  3 . 
     The magnet drive  7  comprises a reversible magnet coil  8  having an iron core with two yoke legs  9  pivotably holding an armature  10  with a permanent magnet (not shown). The permanent magnet is disposed between two armature plates  11  which each abut the yoke legs  9  in the two switching positions of the armature  10 . The magnet coil  8  and the armature  10  which can be pivoted between its two switching positions form an H-type armature pull. 
     An actuator  13  formed as one-piece arm is hinged to a projecting arm  12  of the armature  10 , wherein the actuator  13  is disposed such that it can be linearly displaced in the deflecting direction (double arrow  14 ) of the contact spring  4 . The actuator  13  engages with a projection  15  below the free end  5  of the contact spring  4  whereby the actuator  13  carries along or deflects the contact spring  4  in the opening direction of the relay  1  i.e. upwardly. The contact spring  4  is motionally coupled to the actuator  13  in the closing direction, i.e. downwardly, by means of an additional spring  16  supported on the actuator  13 . In the embodiment shown, the additional spring  16  is formed as leaf spring which is mounted by means of a rivet  17  on top of the contact spring  4 , shown in FIG. 3, and whose free end  18  cooperates with a downwardly directed projection  19  of the actuator  13 . As shown in FIG. 3, the free end  18  of the additional spring  16  projects past the free end  5  of the contact spring  4  in the longitudinal direction, i.e. in the direction away from the first relay contact  2 . 
     For switching the relay  1 , the magnetic field of the magnet coil  8  is reversed thereby pivoting the armature  10  and displacing the actuator  13 . In the closed relay position (FIG.  1 ), the actuator  13  is displaced downwardly by the downwardly pivoted arm  12 , whereby also the contact spring  4  is deflected downwardly via the additional spring  16  until its contact button  6  abuts the second relay contact  3 . The pressure of the contact button  6  on the second relay contact  3  is provided by the pressure of the additional spring  16  compressed by the actuator  13 . In the open relay position (FIG.  2 ), the actuator  13  is displaced upwardly through the upwardly pivoted arm  12  thereby carrying along the contact spring  4  from the projection  15  of the actuator  13  and lifting the contact button  6  from the second relay contact  3 . 
     In the variant shown in FIG. 4, the free end  18  of the additional spring  16  which cooperates with the actuator  13  projects laterally past the free end  5  of the contact spring  4 . 
     In the variant of FIG. 5, the free end  18  of the pressure spring  16  is directed away from the free end  5  of the contact spring, i.e. in a direction back to the first relay contact  2 , for cooperation with the actuator  13 . 
     In the relay  1  of FIGS. 6 and 7, the actuator  20  which cooperates with the contact spring  4  is shorter and is motionally coupled to the arm  12  via a coupling spring  21  which is supported between the actuator  20  and the arm  12 . In the closed relay position (FIG. 6) the actuator  20  is displaced downwardly by the downwardly pivoted arm  12  and the coupling spring  21 , whereby the contact spring  4  is also deflected downwardly through the additional spring  16  until the contact button  6  abuts the second relay contact  3 . The pressure of the contact button  6  on the second relay contact  3  is provided by the pressure of the two compressed springs  16 ,  21 . In the open relay position (FIG.  7 ), the actuator  20  is pulled upwards by the upwardly pivoted arm  12  via the coupling spring  21  whereby the contact spring  4  is carried along from the projection  15  of the actuator  13  and the contact button  6  is lifted from the second relay contact  3 .