Linear vibration actuator having moving coil and moving magnet

Abstract

A vibrating actuator for producing two different vibrations is disclosed, comprising a first moving part including at least three magnets, wherein the magnets are arranged with like polarities facing each other; a second moving part including at least two coils, wherein the coils are wound over the magnets; and a pair of first elastic members affixed to a chassis and to the first moving part; and holding means which are affixed to the second moving part and which furthermore either are affixed to the chassis or form part of the pair of first elastic members. The second moving part forms a tubular structure and the first moving part slides within it to allow free movement. The pair of first elastic members and the holding means are attached to the chassis. Furthermore, a method for manufacturing such a vibrating actuator is disclosed.

1 . A vibrating actuator having two different frequencies of vibration, the vibrating actuator comprising:
 a first moving part ( 210 ) including at least three magnets ( 320 ), wherein the magnets ( 320 ) are arranged with like polarities facing each other;   a second moving part ( 220 ) including at least two coils ( 410 ), wherein the coils ( 410 ) are wound over the magnets ( 320 ); and   a pair of first elastic members ( 230 ;  800 ;  1000 ;  1110 ) affixed to a chassis ( 160 ) and to the first moving part ( 210 ); and   holding means ( 240 ;  830 ;  1030 ;  1120 ) which are affixed to the second moving part ( 220 ) and which furthermore either are affixed to the chassis ( 160 ) or form part of the pair of first elastic members ( 230 ;  800 ;  1000 ).   
     
     
         2 . The vibrating actuator according to  claim 1 , wherein
 the pair of first elastic members ( 230 ) is affixed to the chassis ( 160 ) at one end and to the first moving part ( 210 ) at the other end; and   wherein the holding means ( 240 ) are a pair of second elastic members affixed to the chassis ( 160 ) at one end and the second moving part ( 220 ) at the other end.   
     
     
         3 . The vibrating actuator of  claim 1 , wherein the pair of first elastic members ( 230 ;  800 ;  1000 ;  1110 ) produce a first vibration frequency and the holding means ( 240 ;  830 ;  1030 ;  1120 ) produce a second vibration frequency, wherein the first vibration frequency is different than the second vibration frequency and the first moving part ( 210 ) and the second moving part ( 220 ) vibrate along the longitudinal axis in opposite directions. 
     
     
         4 . The vibrating actuator of  claim 1 , wherein the chassis ( 160 ) has protruding elements ( 162 ,  164 ) at diagonally opposite ends along the longitudinal axis having means to attach the pair of first elastic members ( 230 ;  800 ;  1000 ;  1110 ) and the holding means ( 240 ;  830 ;  1030 ;  1120 ) either by welding or affixing with screws. 
     
     
         5 . The vibrating actuator of  claim 1 , wherein the holding means ( 240 ;  830 ;  1030 ;  1120 ) has a provision for carrying current to the coils ( 410 ) by overlaying a conductive path on at least one elastic member ( 240 A,  240 B), wherein the overlaid path is made of a flexible printed circuit or a wire. 
     
     
         6 . The vibrating actuator of  claim 1 , wherein the holding means ( 240 ;  830 ;  1030 ;  1120 ) has a provision for carrying current to the coils ( 410 ) by acting as a conductive path. 
     
     
         7 . The vibrating actuator of  claim 1 , wherein the first moving part ( 210 ) comprises a frame ( 310 ) and the magnets ( 320 ) and wherein the magnets ( 322 ,  324 ,  326 ) have equal transverse width and at least two magnets ( 322 ,  326 ) have equal longitudinal length. 
     
     
         8 . The vibrating actuator of  claim 7 , wherein the magnets ( 322 ,  324 ,  326 ) have a spacer made of nonmagnetic material embedded at the intersection of the magnets ( 320 ). 
     
     
         9 . The vibrating actuator of  claim 7 , wherein the frame ( 310 ) is a square or rectangle and is made of a non-ferromagnetic material. 
     
     
         10 . The vibrating actuator of  claim 1 , wherein the first moving part ( 210 ) comprises a frame ( 310 ) and wherein the coils ( 410 ) are wrapped transversally around a frame ( 310 ) to form a longitudinal tubular structure to allow free movement of the coils ( 410 ) over the frame ( 310 ). 
     
     
         11 . The vibrating actuator of  claim 1 , wherein the coils ( 410 ), which are a pair of coils ( 412 ,  414 ), are attached to each other such that the coils ( 412 ,  414 ) carry current and are wound in opposite directions. 
     
     
         12 . The vibrating actuator of  claim 11 , further comprising a pair of U-shaped structures ( 420 ), wherein each U-shaped structure ( 420 A,  420 B) is attached to the coils ( 412 ,  414 ) such that the U-shaped structures ( 420 A,  420 B) are aligned opposite to each other. 
     
     
         13 . The vibrating actuator of  claim 12 , wherein the U-shaped structures ( 420 ) and the coils ( 410 ) are connected to form a hollow tubular structure that slides over a frame ( 310 ) to allow free movement of the second moving part ( 220 ) and the first moving part ( 210 ) and wherein the number of coils ( 410 ) is one less than the number of magnets ( 320 ). 
     
     
         14 . The vibrating actuator of  claim 12 , wherein the U-shaped structures ( 420 ) are closed at the open face to form a tubular structure. 
     
     
         15 . The vibrating actuator of  claim 1 , wherein the pair of first elastic members ( 230 ) are made of stainless steel having a Z like shape with two flat protruding elements ( 602 ,  610 ) in opposite directions. 
     
     
         16 . The vibrating actuator of  claim 1 , wherein the pair of first elastic members ( 230 ;  800 ;  1000 ;  1110 ) are perforated. 
     
     
         17 . The vibrating actuator of  claim 15 , wherein the pair of first elastic members ( 230 ) are a long strip ( 606 ) connecting the two flat protruding elements ( 602 ,  610 ), which are parallel to each other, folded at 90 degrees with rounded edges, and wherein one of the protruding elements ( 602 ) is substantially larger than the other protruding element ( 610 ) and the flat strip connecting the protruding elements ( 602 ,  610 ) has traversal indentations symmetrical along the centre of the long strip ( 606 ). 
     
     
         18 . The vibrating actuator of  claim 2 , wherein the holding means ( 240 ) comprising the pair of second elastic members are broader along the Z-axis than the pair of first elastic members ( 230 ) and are made of stainless steel with a Z like shape having two flat protruding elements ( 702 ,  710 ) projecting in opposite directions. 
     
     
         19 . The vibrating actuator of  claim 18 , wherein the holding means ( 240 ) includes a long strip ( 706 ) connecting the two flat protruding elements ( 702 ,  710 ) and has transversal indentations symmetrical along the centre of the long strip ( 706 ). 
     
     
         20 . The vibrating actuator of  claim 1 , wherein the holding means ( 240 ;  830 ;  1030 ;  1120 ) are perforated. 
     
     
         21 . The vibrating actuator according to  claim 1 ,
 wherein each of the pair of first elastic members ( 800 ) comprises
 a base plate ( 802 ) which is affixed to the chassis ( 160 ) and 
 a middle strip ( 806 ) which projects from the base plate ( 802 ) and which is affixed to the first moving part ( 210 ); and 
   wherein the holding means ( 830 ) comprise a pair of outer strips ( 804 A,  804 B), which project from the base plate ( 802 ) and which are affixed to the second moving part ( 220 ).   
     
     
         22 . The vibrating actuator according to  claim 1 ,
 wherein each of the pair of first elastic members ( 1000 ) comprises:
 a base plate ( 1002 ) which is affixed to the chassis ( 160 ) and 
 a first elastic member ( 1004 ) which projects from the base plate ( 1002 ) and which is affixed to the first moving part ( 210 ); and 
   wherein the holding means ( 1030 ) comprise a second elastic member ( 1006 ), which projects from the base plate ( 1002 ) and which is affixed to the second moving part ( 220 ).   
     
     
         23 . A method for manufacturing a vibrating actuator, comprising the following steps:
 assembling a first moving part ( 210 ) by assembling at least three magnets ( 322 ,  324 ,  326 ) in a rectangular frame ( 310 ), wherein the magnets ( 320 ) with like polarities face each other;   assembling a second moving part ( 220 ) by wrapping at least two coils ( 412 ,  414 ) of self-bonding copper wire around the rectangular frame ( 310 ), wherein the at least two coils ( 412 ,  414 ) are attached to a U-shaped structures ( 420 ) such that the first ends of the coils ( 410 ) are attached to each other and the second ends of the coils are attached to the U-shaped structures ( 420 ), wherein the U-shaped structures ( 420 ) are arranged diagonally opposite to each other;   attaching a pair of first elastic members ( 230 ;  800 ;  1000 ,  1110 ) to the first moving part ( 210 ); and   attaching a holding means ( 240 ;  830 ;  1030 ;  1120 ) to the second moving part ( 220 ).