Patent Publication Number: US-2012044030-A1

Title: Relay with multiple coils

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a relay with multiple coils, and more particularly to a relay having multiple coils disposed thereon for increasing an efficiency of an electromagnetic induction and lowering a consumption of the coils. 
     2. Description of Related Art 
     A relay is an electrically operated switch for controlling a circuit by applying a low electric current. The most common types of relays used are electromechanical relays, reed relays, and solid state relays, etc. A conventional electromagnetic relay in accordance with the prior art comprises an iron core. A single coil is wound around the iron core. A magnet is disposed above the iron core and the single coil. A spring is connected to the magnet for restoring the magnet. Accordingly, two distal ends of the single coil is respectively applied two different voltages to generate an electric current for passing through the single coil, such that a magnetic field is induced by the electric current for attracting the magnet to move toward the iron core. And when no electric current passes through the single coil, the magnetic field is disappeared. The magnet is drawn back by the spring. 
     However, the conventional electromagnetic relay only has the single coil. The induced magnetic field can be enhanced without changing the input voltages by increasing a length or a diameter of the coil or increasing a length of the iron core. This causes an increase of a size of the single coil and is inconvenient to dispose on a small-scale relay. 
     The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional electromagnetic relay with a single coil. 
     SUMMARY OF THE INVENTION 
     The main objective of the present invention is to provide an improved relay with multiple coils for increasing an induced magnetic field. 
     To achieve the objective, the relay with multiple coils in accordance with the present invention includes a base having at least one fixed contact disposed thereon. 
     At least one coil assembly is mounted on the base. Each coil assembly comprises at least one U-shaped iron core disposed on the base. Each U-shaped iron core has two legs. Two tubular bobbins respectively and coaxially receive the two legs of each iron core. Each tubular bobbin has a square cross section. Two coils are respectively and coaxially wound around the two tubular bobbins. Each tubular bobbin which is wound by the corresponding coil has an attracted end formed thereon and located at one end of the corresponding leg of the iron core. 
     A spring member is pivotally connected to the base. The spring member has at least one moving contact disposed on one end thereof and movably connected with the at least one fixed contact of the base for providing a switching effect. The spring member has a magnetic member rivetedly mounted thereon and located adjacent to the at least one moving contact. The magnetic member corresponds to the attracted ends of the at least one coil assembly and is in a face-to-face relation with the attracted ends. The spring member selectively provides a restoring force on the at least one moving contact and the magnetic member. 
     When the at least one coil assembly is induced a magnetic field by supplying electric current, the magnetic member is magnetically attracted to move toward and connect with the attracted ends of the at least one coil assembly by the magnetic field. The spring member is driven to pivotally move toward the at least one coil assembly. The at least one moving contact moves away from the at least one fixed contact by a movement of the spring member. 
     When no electric current is supplied to the at least one coil assembly, the magnetic member is released from the attracted ends. The spring member provides the restoring force to move the magnetic member and the at least one moving contact backward. The at least one moving contact moves to connect with the at least one fixed contact. Accordingly, the relay acts as a switch for adapting to open/close a circuit connected to the relay. 
     In accordance with another aspect of the present invention, each tubular bobbin has a round cross section. 
     Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a preferred embodiment of a relay with multiple coils in accordance with the present invention; 
         FIG. 2  is an assembled perspective view of the preferred embodiment of the relay with multiple coils in accordance with the present invention; 
         FIGS. 3-4  are operational side plane views of the preferred embodiment of the relay with multiple coils in accordance with the present invention; 
         FIG. 5  is an assembled perspective view of a second embodiment of the relay with multiple coils in accordance with the present invention; 
         FIGS. 6-7  are operational side plane views of the second embodiment of the relay with multiple coils in accordance with the present invention; and 
         FIG. 8  is an exploded perspective view of a third embodiment of the relay with multiple coils in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and initially to  FIGS. 1-2 , a relay with multiple coils in accordance with a preferred embodiment of the present invention is in a flapping motion version and comprises a base  1  having a wall (not numbered) vertically and laterally disposed on a top thereof. The base  1  has a fixed contact  11  disposed on the wall thereof. 
     A coil assembly  3  is mounted on the top of the base  1  and located adjacent to the wall. The coil assembly  3  comprises a U-shaped iron core  31  having two spaced legs (not numbered) extending upwardly therefrom. Two tubular bobbins  32  respectively and coaxially receive the two legs of the iron core  31 . Each tubular bobbin  32  has a square cross section. Two coils  33  are respectively and coaxially wound around the two tubular bobbins  32 . Each tubular bobbin  32  which is wound by the corresponding coil  33  has an attracted end  321  formed thereon and located at a free end of the corresponding leg of the iron core  31 . 
     A spring member  2  is pivotally connected to the base  1 . The spring member  2  has an inverted L shape with a vertical arm and a horizontal arm (not numbered). A free end of the vertical arm of the spring member  2  is fixed to the top of the base  1  and located adjacent to the coil assembly  3 . The horizontal arm of the spring member  2  movably extends toward the wall of the base  1  and is slightly warped up. A free end of the horizontal arm has a moving contact  21  disposed thereon and movably correspondingly connected with the fixed contact  11  of the base  1  for providing a switching effect. The spring member  2  has a magnetic member  22  rivetedly mounted on a bottom of the horizontal arm and located adjacent to the moving contact  21 . The magnetic member  22  spacedly corresponds to the attracted ends  321  of the coil assembly  3  and is in a face-to-face relation with the attracted ends  321 . The spring member  2  selectively provides a restoring force on the moving contact  21  and the magnetic member  22  of the horizontal arm. 
     The operation of the relay with multiple coils in accordance with the present invention will be described in detailed below. As shown in  FIG. 3 , when each coil  33  of the coil assembly  3  is induced a magnetic field by supplying electric current, the magnetic member  22  of the spring member  2  is magnetically attracted to move toward and connect with the attracted ends  321  of the two tubular bobbins  32  by the magnetic field. The horizontal arm of the spring member  2  pivotally moves downwardly to the coil assembly  3  with the attracted magnetic member  22 . The moving contact  21  moves away from the fixed contact  11  by a movement of the horizontal arm of the spring member  2 . 
     As shown in  FIG. 4 , when no electric current is supplied to the two coils  33  and the magnetic field is disappeared, the magnet  22  is released from the attracted ends  321 . The spring member  2  provides the restoring force to draw the magnet  22  and the moving contact  21  of the horizontal arm backward. The moving contact  21  moves upwardly to connect with the fixed contact  11  again. Accordingly, the relay with multiple coils acts as a switch for opening/closing a circuit (not shown) connected to the relay. 
     With reference to  FIGS. 5-7 , that shows a second embodiment of the relay with multiple coils in accordance with the present invention. The second embodiment is in a vertical motion version. The elements and effects of the second embodiment which are the same with the preferred embodiment are not described, only the differences are described. In this embodiment, the base  4  has two walls (not numbered) vertically disposed on two opposite sides of a top thereof. The base  4  has two fixed contacts  41  respectively disposed on the two walls thereof. The coil assembly  6  is mounted on the top of the base  4  and located between the two walls. The coil assembly  6  has a plurality of attracted ends  61  formed thereon 
     A spring member  5  is movably located above the coil assembly  6 . The spring member  5  has two moving contacts  51  respectively disposed on two opposite ends thereof for corresponding to the two fixed contacts  41  of the base  4 . A magnetic member  52  is rivetedly mounted on a bottom of the spring member  5  and located between the two moving contacts  51 . The magnetic member  52  spacedly corresponds to the attracted ends  61  of the coil assembly  6  and is in a face-to-face relation with the attracted ends  61 . A coil spring  53  is compressibly disposed between the magnetic member  52  and the attracted ends  61  of the coil assembly  6 . The coil spring  53  has two ends abutting against the magnetic member  52  and the coil assembly  6 . 
     As shown in  FIGS. 6-7 , when the magnetic member  52  is magnetically attracted by the induced magnetic field in the coil assembly  6  and the coil spring  53  is vertically compressed by the magnetic member  52 , the spring member  5  moves downwardly to the coil assembly  6  with the attracted magnetic member  52 . The two moving contacts  51  simultaneously move downwardly to connect with the two fixed contacts  41  of the base  4 . When no magnetic field is induced, the magnetic member  52  is released from the attracted ends  61 . The coil spring  53  provides a restoring force to draw the magnetic member  52  and the two moving contacts  51  of the spring member  5  backward. The two moving contacts  51  move away from the two fixed contacts  41 . 
     With reference to  FIG. 8 , that shows a third embodiment of the relay with multiple coils in accordance with the present invention. The elements and effects of the third embodiment which are the same with the preferred embodiment are not described, only the differences are described. In this embodiment, each tubular bobbin  32   a  has a round cross section and coaxially receives the corresponding leg of the iron core  31   a.    
     Therefore, the induced magnetic field of the conventional relay with a single coil may be enhanced without changing the input voltages by increasing a length or a diameter of the coil or increasing a length of the iron core. The relay with multiple coils in accordance with the present invention overcomes above disadvantages by providing the multiple coils for increasing the induced magnetic field and enhancing the operation of the relay. 
     Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.