PATENT DOCUMENT

Publication Number: US-11305182-B2
Application Number: US-201716320345-A
Country: US
Kind Code: B2

Title: Haptic actuator including flexure bearing having diverging arms each with a reduced size medial portion and related methods

Abstract:
A haptic actuator may include a housing, at least one coil carried by the housing, and a field member having opposing first and second sides. The haptic actuator may also include a respective at least one flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing may include two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing. The two diverging arms may each have a reduced size medial portion relative to respective proximal and distal ends.

Claims:
That which is claimed is: 
     
       1. A haptic actuator comprising:
 a housing; 
 at least one coil carried by the housing; 
 a field member having opposing first and second sides; and 
 a respective at least one flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil; 
 each flexure bearing comprising two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing, the two diverging arms each having,
 a respective length extending between a respective proximal end and a respective distal end; and 
 a respective reduced size medial portion relative to the respective proximal end and the respective distal end; wherein, 
 the respective reduced size medial portion is transverse to the respective length. 
 
 
     
     
       2. The haptic actuator of  claim 1  wherein each flexure bearing further comprises a spacer member between the proximal ends of the two diverging arms. 
     
     
       3. The haptic actuator of  claim 2  further comprising a weld joint joining together the spacer member and the proximal ends of the two diverging arms. 
     
     
       4. The haptic actuator of  claim 1  wherein each diverging arm comprises first and second parallel and spaced apart blades. 
     
     
       5. The haptic actuator of  claim 4  wherein each diverging arm comprises proximal and distal end spacers between the first and second parallel and spaced apart blades. 
     
     
       6. The haptic actuator of  claim 5  further comprising respective weld joints joining together the proximal and distal end spacers and adjacent portions of the spaced apart blades. 
     
     
       7. The haptic actuator of  claim 4  wherein each diverging arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     
     
       8. The haptic actuator of  claim 1  wherein each flexure bearing has a wishbone shape. 
     
     
       9. The haptic actuator of  claim 1  wherein each flexure bearing comprises at least one mechanical stop adjacent the proximal ends. 
     
     
       10. The haptic actuator of  claim 1  wherein each flexure bearing comprises at least one mechanical stop between the spaced distal ends. 
     
     
       11. An electronic device comprising:
 a housing; 
 wireless communications circuitry carried by the housing; 
 a haptic actuator carried by the housing and comprising
 an actuator housing, 
 at least one coil carried by the actuator housing, 
 a field member having opposing first and second sides, and 
 a respective at least one flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil, 
 each flexure bearing comprising two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing, the two diverging arms each having, 
 a respective length extending between a respective proximal end and a respective distal end; and 
 a respective reduced size medial portion relative to the respective proximal end and the respective distal end; wherein, 
 the respective reduced size medial portion is transverse to the respective length; and 
 
 a controller coupled to the wireless communications circuitry and the haptic actuator and configured to perform at least one wireless communications function and selectively operate the haptic actuator. 
 
     
     
       12. The electronic device of  claim 11  wherein each flexure bearing further comprises a spacer member between the proximal ends of the two diverging arms. 
     
     
       13. The electronic device of  claim 12  wherein the haptic actuator further comprises a weld joint joining together the spacer member and the proximal ends of the two diverging arms. 
     
     
       14. The electronic device of  claim 11  wherein each diverging arm comprises first and second parallel and spaced apart blades. 
     
     
       15. The electronic device of  claim 14  wherein each diverging arm comprises proximal and distal end spacers between the first and second parallel and spaced apart blades. 
     
     
       16. The electronic device of  claim 14  wherein each diverging arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     
     
       17. A method of making a haptic actuator comprising:
 positioning a respective at least one flexure bearing to mount each of first and second sides of a field member to be reciprocally movable within a housing responsive to at least one coil, each flexure bearing comprising two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing, the two diverging arms each having, 
 a respective length extending between a respective proximal end and a respective distal end; and 
 a respective reduced size medial portion relative to the respective proximal end and the respective distal end; wherein, 
 the respective reduced size medial portion is transverse to the respective length. 
 
     
     
       18. The method of  claim 17  wherein each flexure bearing further comprises a spacer member between the proximal ends of the two diverging arms. 
     
     
       19. The method of  claim 17  wherein each diverging arm comprises first and second parallel and spaced apart blades. 
     
     
       20. The method of  claim 19  wherein each diverging arm comprises proximal and distal end spacers between the first and second parallel and spaced apart blades. 
     
     
       21. The method of  claim 19  wherein each diverging arm further comprises a filler body between the first and second parallel and spaced apart blades.

Description:
TECHNICAL FIELD 
     The present disclosure relates to the field of electronics, and, more particularly, to the field of haptics. 
     BACKGROUND 
     Haptic technology is becoming a more popular way of conveying information to a user. Haptic technology, which may simply be referred to as haptics, is a tactile feedback based technology that stimulates a user&#39;s sense of touch by imparting relative amounts of force to the user. 
     A haptic device or haptic actuator is an example of a device that provides the tactile feedback to the user. In particular, the haptic device or actuator may apply relative amounts of force to a user through actuation of a mass that is part of the haptic device. Through various forms of tactile feedback, for example, generated relatively long and short bursts of force or vibrations, information may be conveyed to the user. 
     SUMMARY 
     A haptic actuator may include a housing, at least one coil carried by the housing, and a field member having opposing first and second sides. The haptic actuator may also include a respective at least one flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing may include two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing. The two diverging arms may each have a reduced size medial portion relative to respective proximal and distal ends. 
     Each arm may have a blade shape having a length between respective proximal and distal ends, a thickness, and height with a varying profile defining the reduced sized medial portion, for example. Each flexure bearing may also include a spacer member between the proximal ends of the two diverging arms. The haptic actuator may further include a weld joint joining together the spacer member and the proximal ends of the two diverging arms, for example. 
     Each diverging arm may include first and second parallel and spaced apart blades. Each diverging arm may include proximal and distal end spacers between the first and second parallel and spaced apart blades, for example. 
     The haptic actuator may also include respective weld joints joining together the proximal and distal end spacers and adjacent portions of the spaced apart blades, for example. Each diverging arm may also include a filler body between the first and second parallel and spaced apart blades, for example. 
     Each flexure bearing may have a wishbone shape. Each flexure bearing may include at least one mechanical stop adjacent the proximal end. Each flexure bearing may include at least one mechanical stop between the spaced distal ends, for example. 
     A method aspect is directed to a method of making a haptic actuator. The method may include positioning a respective at least one flexure bearing to mount each of first and second sides of a field member to be reciprocally movable within a housing responsive to at least one coil. Each flexure bearing may include two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing. The two diverging arms may each have a reduced size medial portion relative to respective proximal and distal ends. 
     Another device aspect is directed to a haptic actuator that may include a housing, at least one permanent magnet carried by the housing, and a field member having opposing first and second sides and that includes at least one coil cooperating with the at least one permanent magnet. The haptic actuator may also include a respective at least one flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing includes two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing, the two diverging arms each having a reduced size medial portion relative to respective proximal and distal ends. 
     A method aspect is directed to a method of making a haptic actuator. The method may include positioning a respective at least one flexure bearing to mount each of first and second sides of a field member to be reciprocally movable within a housing responsive to at least one coil. The housing carries at least one permanent magnet cooperating with the at least one coil. Each flexure bearing includes two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing, the two diverging arms each having a reduced size medial portion relative to respective proximal and distal ends. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an electronic device including a haptic actuator according to an embodiment. 
         FIG. 2  is a schematic block diagram of the electronic device of  FIG. 1 . 
         FIG. 3  is a schematic block diagram of the haptic actuator of the electronic device of  FIG. 1 . 
         FIG. 4  is a perspective view of a portion of a haptic actuator in accordance with an embodiment. 
         FIG. 5  is an enlarged perspective view of a portion of the flexure bearing of  FIG. 4 . 
         FIG. 6  is top view of the flexure bearing of  FIG. 5 . 
         FIG. 7  is a side view of the flexure bearing of  FIG. 5 . 
         FIG. 8  is an exploded view of the flexure bearing of  FIG. 5 . 
         FIG. 9  is a schematic block diagram of a haptic actuator in accordance with an embodiment. 
         FIG. 10  is a perspective view of a portion of a haptic actuator in accordance with an embodiment. 
         FIG. 11  is an enlarged perspective view of a portion of the flexure bearing of  FIG. 10 . 
         FIG. 12  is top view of the flexure bearing of  FIG. 11 . 
         FIG. 13  is a side view of the flexure bearing of  FIG. 11 . 
         FIG. 14  is an exploded view of the flexure bearing of  FIG. 11 . 
         FIG. 15  is a perspective view of a portion of a flexure bearing in accordance with an embodiment. 
         FIG. 16  is a side view of the portion of the flexure bearing of  FIG. 15 . 
         FIG. 17  is a schematic block diagram of a portion of the haptic actuator according to another embodiment. 
         FIG. 18  is a perspective view of a portion of the haptic actuator of  FIG. 17 . 
         FIG. 19  is an enlarged perspective view of the anchor member of the haptic actuator of  FIG. 18 . 
         FIG. 20  is a top view of a parallel spaced apart flexible arm in accordance with an embodiment. 
         FIG. 21  is a side view of a parallel spaced apart flexible arm in accordance with an embodiment. 
         FIG. 22  is a side view of a portion of a parallel spaced apart flexible arm in accordance with an embodiment. 
         FIG. 23  is a schematic block diagram of a haptic actuator according to another embodiment. 
         FIG. 24  is an enlarged perspective view of a portion of a haptic actuator according to another embodiment. 
         FIG. 25  is a side view of a portion of a parallel spaced apart flexible arm in accordance with an embodiment. 
         FIG. 26  is an enlarged perspective view of a haptic actuator in accordance with an embodiment. 
         FIG. 27  is a perspective view of a portion of a haptic actuator according to an embodiment. 
         FIG. 28  is another perspective view of a portion of the haptic actuator in  FIG. 27 . 
         FIG. 29  is a perspective view of a haptic actuator according to another embodiment. 
         FIG. 30  is a perspective view of a portion of a haptic actuator according to an embodiment. 
         FIG. 31  is a perspective view of another portion of the haptic actuator in  FIG. 30 . 
         FIG. 32  is a perspective view of a portion of a haptic actuator in accordance with another embodiment. 
         FIG. 33  is a perspective view of a portion of a haptic actuator according to an embodiment. 
         FIG. 34  is an enlarged perspective view of the flexible member of  FIG. 33 . 
         FIG. 35  is an enlarged perspective view of a flexible member according to another embodiment. 
         FIG. 36  is a perspective view of a portion of a haptic actuator according to an embodiment. 
         FIG. 37  is an enlarged perspective view of a flexure bearing for use with a field member of a haptic actuator in accordance with an embodiment. 
         FIG. 38  is an enlarged schematic top view of a portion of a haptic actuator including a flexure bearing in accordance with an embodiment. 
         FIG. 39  is an enlarged schematic top view of a portion of a haptic actuator including a flexure bearing in accordance with an embodiment. 
         FIG. 40  is an enlarged schematic top view of a portion of a haptic actuator including a flexure bearing in accordance with an embodiment. 
         FIG. 41  is an enlarged schematic top view of a portion of a haptic actuator including a flexure bearing in accordance with an embodiment. 
         FIG. 42  is an enlarged schematic top view of a portion of a haptic actuator including a flexure bearing in accordance with an embodiment. 
         FIG. 43  is a block diagram of a haptic actuator in accordance with an embodiment. 
         FIG. 44  is a perspective view of a portion of a haptic actuator in accordance with an embodiment. 
         FIG. 45  is a block diagram of a haptic actuator in accordance with another embodiment. 
         FIG. 46  is a perspective view of a portion of a haptic actuator in accordance with another embodiment. 
         FIG. 47  is a perspective view of a portion of a haptic actuator in accordance with another embodiment. 
         FIG. 48  is an enlarged perspective view of the flexure bearing of FIG. 
         FIG. 49  is an exploded perspective view of the flexure bearing of  FIG. 47 . 
         FIG. 50  is an exploded side view of the flexure bearing of  FIG. 47 . 
         FIG. 51  is an exploded top view of the flexure bearing of  FIG. 47 . 
         FIG. 52  is an enlarged perspective view of a flexure bearing in accordance with another embodiment. 
         FIG. 53  is an exploded side view of the flexure bearing of  FIG. 52 . 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime and multiple prime notations and refer to like elements in different embodiments. 
     Referring initially to  FIGS. 1-2 , an electronic device  20  illustratively includes a device housing  21  and a controller  22  carried by the device housing. The electronic device  20  is illustratively a mobile wireless communications device, for example, a wearable wireless communications device, and includes a band  28  or strap for securing it to a user. The electronic device  20  may be another type of electronic device, for example, a cellular telephone, a tablet computer, a laptop computer, etc. 
     Wireless communications circuitry  25  (e.g. cellular, WLAN Bluetooth, etc.) is also carried within the device housing  21  and coupled to the controller  22 . The wireless communications circuitry  25  cooperates with the controller  22  to perform at least one wireless communications function, for example, for voice and/or data. In some embodiments, the electronic device  20  may not include wireless communications circuitry  25 . 
     A display  23  is also carried by the device housing  21  and is coupled to the controller  22 . The display  23  may be, for example, a liquid crystal display (LCD), light emitting diode (LED) display, or may be another type of display, as will be appreciated by those skilled in the art. The display  23  may be a touch display. 
     Finger-operated user input devices  24   a ,  24   b , illustratively in the form of a pushbutton switch and a rotary dial are also carried by the device housing  21  and are coupled to the controller  22 . The pushbutton switch  24   a  and the rotary dial  24   b  cooperate with the controller  22  to perform a device function in response to operation thereof. For example, a device function may include a powering on or off of the electronic device  20 , initiating communication via the wireless communications circuitry  25 , and/or performing a menu function. 
     The electronic device  20  illustratively includes a haptic actuator  40 . The haptic actuator  40  is coupled to the controller  22  and provides haptic feedback to the user in the form of relatively long and short vibrations or “taps”, particularly when the user is wearing the electronic device  20 . The vibrations may be indicative of a message received, and the duration of the vibration may be indicative of the type of message received. Of course, the vibrations may be indicative of or convey other types of information. More particularly, the controller  22  applies a voltage to move a movable body or masses between first and second positions in a y-axis. 
     While a controller  22  is described, it should be understood that the controller  22  may include one or more of a processor and other circuitry to perform the functions described herein. For example, the controller  22  may include a class-D amplifier to drive the haptic actuator  40  and/or sensors for sensing voltage and current. 
     Referring now additionally to  FIGS. 3-8  the haptic actuator  40  includes an actuator housing  41 . The actuator housing  41  illustratively has a dimension in a length direction greater than a width direction. The actuator housing  41  may include ferritic material in portions of or all of the actuator housing. For example, the top and bottom of the actuator housing  41  may be ferritic. Of course other and/or additional portions of the actuator housing  41  may be ferritic. The use of ferritic material in the actuator housing  41  may improve performance, for example. 
     The haptic actuator  40  also includes first and second coils  44 ,  45  carried by the actuator housing  41 , for example, the top and the bottom, respectively. The first and second coils  44 ,  45  may each have a loop shape or “racetrack” shape and are aligned in a stacked relation and spaced apart. There may be any number of first and second coils  44 ,  45 , as will be appreciated by those skilled in the art. Moreover, in some embodiments, the first and/or second coils  44 ,  45  may be carried by the actuator housing around an exterior thereof, i.e., a circumferential voice coil. 
     The haptic actuator  40  also includes a field member  50  carried by the actuator housing  41 . The field member  50 , similarly to the actuator housing  41 , has a dimension in a length direction greater than a width direction. Thus, the field member  50  is reciprocally movable in the width direction (i.e., the y-direction). While the movement of the field member  50  is described as being movable in one direction, i.e., a linear haptic actuator, it should be understood that in some embodiments, the field member may be movable in other directions, i.e., an angular haptic actuator, or may be a combination of both a linear and an angular haptic actuator. 
     The field member  50  illustratively includes permanent magnets  51   a - 51   d  between the first and second coils  44 ,  45 . The permanent magnets  51   a - 51   d  may be neodymium, for example, and may be positioned in opposing directions with respect to their respective poles. 
     The permanent magnets  51   a - 51   d  may be aligned along a length of the first and second coils  44 ,  45 . While four shaped permanent magnets  51   a - 51   d  are illustrated, it will be appreciated that there may be any number of permanent magnets having any shape between the first and second coils  44 ,  45 . The permanent magnets  51   a - 51   d  may be arranged as a Halbach array. Referring briefly to  FIG. 9 , in some embodiments, the position of the coils  44 ′,  45 ′ and the permanent magnets  51   a ′- 51   d ′ may be reversed. In other words, the first and second coils  44 ′,  45 ′ may be carried by or part of the field member  50 ′, while the permanent magnets  51   a ′- 51   d ′ are stationary or carried by the actuator housing  41 ′ (i.e., a moving coil configuration). 
     The field member  50  also includes masses  57   a ,  57   b  adjacent the permanent magnets  51   a - 51   d . The masses  57   a ,  57   b  may be tungsten, for example. The masses  57   a ,  57   b  may be a different material and there may any number of masses. In some embodiments, the position of the coils  44 ,  45  and the permanent magnets  51   a - 51   d  may be reversed. In other words, the first and second coils  44 ,  45  may be carried by or part of the field member  50 , while the permanent magnets  51   a - 51   d  are stationary (i.e., a moving coil configuration). 
     The haptic actuator  40  also includes respective flexure bearings  60  mounting each of first and second sides  53 ,  54  of the field member  50  to be reciprocally movable within the actuator housing  41  responsive to the first and second coils  44 ,  45 . Each flexure bearing  60  is illustratively in the shape of a wishbone and includes two diverging arms  61   a ,  61   b , joined together at proximal ends  62   a ,  62   b . The two diverging arms  61   a ,  61   b  each have spaced distal ends  63   a ,  63   b  that are operatively coupled between adjacent portions of the field member  50  and the actuator housing  41 . In some embodiments, each flexure bearing  60  may not be in a wishbone shape, but may have another shape. 
     The two diverging arms  61   a ,  61   b  may include steel, titanium, and/or copper. The two diverging arms  61   a ,  61   b  may include other and/or additional materials. 
     The two diverging arms  61   a ,  61   b  each have a reduced size medial portion  64   a ,  64   b  relative to respective proximal and distal ends. More particularly, each arm  61   a ,  61   b  has a blade shape having a length between respective proximal and distal ends, a thickness, and height with a varying profile defining the reduced sized medial portion  64   a ,  64   b.    
     Each flexure bearing  60  also includes a spacer member  65  between the proximal ends  62   a ,  62   b  of the two diverging arms  61   a ,  61   b . A respective weld joint  66  joins together the spacer member  65  and the proximal ends  62   a ,  62   b  of the two diverging arms  61   a ,  61   b.    
     The reduced size medial portion  64   a ,  64   b  may advantageously distribute stresses over each arm  61   a ,  61   b  thus constituting an improved use of the material. In contrast, in a flat arm, or uniform size arm, stresses are mostly distributed along edges of the arm. More particularly, each arm is patterned (e.g. stamped) with the illustrated curved pattern defining the reduced size medial portion to distribute the stress more uniformly over the length of the arms and away from the weld joints to reduce the risk of fatigue and improve the flexure travel range at low frequencies by up to 1.5 times. 
     Each flexure bearing illustratively includes mechanical stops  72   a ,  72   b  adjacent the proximal ends  62   a ,  62   b . More particularly, first and second mechanical stops  72   a ,  72   b  are between the proximal ends  62   a ,  62   b  and the actuator housing  41  and the field member  50 , respectively. The first and second mechanical stops  72   a ,  72   b  may be an elastomeric material, for example, having a hardness between 38-90. A third mechanical stop  73  is carried by the distal end  63   a  of one of the diverging arms  61   a , and more particularly, is between the distal ends  63   a ,  63   b . The third mechanical stop  73  may be a material similar to the first and second mechanical stops  72   a ,  72   b . The third mechanical stop  73  may be carried by the other diverging arm  61   b.    
     A respective anchor member  75  is coupled between each flexure bearing  60  and the adjacent portions of the housing  41 . More particularly, the anchor member  75  is coupled between a distal end  63   a  of an arm  61   a  and the housing  41 . 
     Referring now to  FIGS. 10-14 , in another embodiment, each diverging arm  61   a ″,  61   b ″ includes first and second parallel and spaced apart blades  67   a ″,  67   b ″ each, similarly to the embodiments described above, has a reduced size medial portion  64   a ″,  64   b ″ relative to respective proximal and distal ends  62   a ″,  62   b ″,  63   a ″,  63   b ″. More particularly, each spaced apart blade  67   a ″,  67   b ″ of each arm  61   a ″,  61   b ″ has a length between respective proximal and distal ends  62   a ″,  62   b ″,  63   a ″,  63   b ′, a thickness, and height with a varying profile defining the reduced sized medial portion  64   a ″,  64   b″.    
     Distal end spacers  68   a ″,  68   b ″ are between the first and second parallel and spaced apart blades  67   a ″,  67   b ″. Each flexure bearing  60 ″ has a wishbone shape. Each flexure bearing  60 ″ may not have a wishbone shape in some embodiments. Respective weld joints  66   a ″,  66   b ″ join together the proximal and distal end spacers  65 ″,  68   a ″,  68   b ″ and adjacent portions of the spaced apart blades  67   a ″,  67   b″.    
     Referring briefly to  FIGS. 15 and 16 , in some embodiments, each diverging arm  61   a ′″,  61   b ′″ includes a filler body  71 ′″ between the first and second parallel and spaced apart blades  67   a ′″,  67   b ′″. The filler body  71 ′″ may include a relatively soft material or bumper material, for example, an elastic material, silicone, and/or foam and follows the contour of the first and second blades  67   a ′″,  67   b ′″. The filler body  71 ′″ may act as a crash stop, for example, to reduce failure in an event of a crash. Of course, the filler body  71 ′″ may be another and/or include other materials, for example, and may be the same as the first, second, and/or third mechanical stops. As will be appreciated by those skilled in the art, at a relatively low frequency, the filler body  71 ′″ may not have a relatively large effect on the flexure bearing  60 ′″, but upon a drop of the haptic actuator or at a relatively high frequency, the filler material provides increased protection against a failure. 
     Referring again to  FIGS. 10-14 , in some embodiments, the spaced apart blades  67   a ″,  67   b ″ may be covered, partially or completely, in a bumper material. As will be appreciated by those skilled in the art, in addition to the advantages described in the above embodiments, moving from one blade to two spaced apart blades  67   a ″,  67   b ″ torsion, for example, at the distal ends  63   a ″,  63   b ″, may be limited while maintaining relatively easy bending motion in the x-axis direction. Stresses are applied to or spread over two pairs of (i.e., four) blades instead of the two arms as in the embodiment described above. In other modes, i.e., movement in the y-axis and z-axis directions, stiffness is relatively maintained. Thus, the bandwidth of the actuator may be increased, for example, by up to two times. 
     Moreover, the proximal ends  62   a ″,  62   b ″ may be considered a relatively robust stop in addition to the mechanical stop  73 ″ between the distal ends  63   a ″,  63   b ″. This may reduce the risk of flexure deformation during drops in the x-axis direction. Additionally, considering the significant improvement in z-axis stiffness, stronger EM engines, for example, in the form of larger magnets, a larger number of stages, and complex magnet arrays such as Halbach arrays, may be supported without giving much consideration of the magnetic anti-spring and the resulting z-axis tolerance amplification (manufacturing/yield risk). Elements in the illustrated embodiment that are not specifically described with respect to the present embodiment are similar to the elements described above and need no further discussion. 
     A method aspect is directed to a method of making a haptic actuator  40 . The method includes positioning a respective flexure bearing  60  to mount each of first and second sides  53 ,  54  of a field member  50  to be reciprocally movable within a housing  41  responsive to at least one coil  44 ,  45 , each flexure bearing including two diverging arms  61   a ,  61   b  joined together at proximal ends  62   a ,  62   b  and having spaced distal ends  63   a ,  63   b  operatively coupled between adjacent portions of the field member and the housing. The two diverging arms each have a reduced size medial portion  64   a ,  64   b  relative to respective proximal and distal ends  62   a ,  62   b ,  63   a ,  63   b.    
     A haptic actuator comprises a housing, at least one permanent magnet carried by the housing, and a field member having opposing first and second sides and comprising at least one coil cooperating with the at least one permanent magnet. The haptic actuator also includes a respective at least one flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing comprises two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing, and the two diverging arms each having a reduced size medial portion relative to respective proximal and distal ends. 
     Each arm has a blade shape having a length between respective proximal and distal ends, a thickness, and height with a varying profile defining the reduced sized medial portion. 
     Each flexure bearing further comprises a spacer member between the proximal ends of the two diverging arms. 
     The haptic actuator further comprises a weld joint joining together the spacer member and the proximal ends of the two diverging arms. 
     Each diverging arm comprises first and second parallel and spaced apart blades. 
     Each diverging arm comprises proximal and distal end spacers between the first and second parallel and spaced apart blades. 
     The haptic actuator further comprises respective weld joints joining together the proximal and distal end spacers and adjacent portions of the spaced apart blades. 
     Each diverging arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     Each flexure bearing has a wishbone shape. 
     Each flexure bearing comprises at least one mechanical stop adjacent the proximal ends. 
     Each flexure bearing comprises at least one mechanical stop between the spaced distal ends. 
     An electronic device comprises a housing, wireless communications circuitry carried by the housing, and a haptic actuator carried by the housing. The haptic actuator comprises an actuator housing, at least one permanent magnet carried by the actuator housing, and a field member having opposing first and second sides and comprising at least one coil cooperating with the at least one permanent magnet. The haptic actuator comprises a respective at least one flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing comprises two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing, the two diverging arms each having a reduced size medial portion relative to respective proximal and distal ends. The electronic device comprises a controller coupled to the wireless communications circuitry and the haptic actuator and configured to perform at least one wireless communications function and selectively operate the haptic actuator. 
     Each arm has a blade shape having a length between respective proximal and distal ends, a thickness, and height with a varying profile defining the reduced sized medial portion. 
     Each flexure bearing further comprises a spacer member between the proximal ends of the two diverging arms. 
     The haptic actuator further comprises a weld joint joining together the spacer member and the proximal ends of the two diverging arms. 
     Each diverging arm comprises first and second parallel and spaced apart blades. 
     Each diverging arm comprises proximal and distal end spacers between the first and second parallel and spaced apart blades. 
     Each diverging arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     A method of making a haptic actuator comprises positioning a respective at least one flexure bearing to mount each of first and second sides of a field member to be reciprocally movable within a housing responsive to at least one coil, the housing carrying at least one permanent magnet cooperating with the at least one coil, and each flexure bearing comprising two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing, the two diverging arms each having a reduced size medial portion relative to respective proximal and distal ends. 
     Each arm has a blade shape having a length between respective proximal and distal ends, a thickness, and height with a varying profile defining the reduced sized medial portion. 
     Each flexure bearing further comprises a spacer member between the proximal ends of the two diverging arms. 
     Each diverging arm comprises first and second parallel and spaced apart blades. 
     Each diverging arm comprises proximal and distal end spacers between the first and second parallel and spaced apart blades. 
     Each diverging arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     Referring now to  FIGS. 17-19 , in another embodiment, the haptic actuator  140  includes an actuator housing  141 . The actuator housing  141  illustratively has a dimension in a length direction greater than a width direction. The actuator housing  141  may be ferritic. More particularly, the top and bottom of the actuator housing  141  may be ferritic. Of course other and/or additional portions of the actuator housing  141  may be ferritic. 
     The haptic actuator  140  also includes first and second coils  144 ,  145  carried by the actuator housing  141 , for example, the top and the bottom, respectively. The first and second coils  144 ,  145  each illustratively have a loop shape or “racetrack” shape and are aligned in a stacked relation and spaced apart. 
     The haptic actuator  140  also includes a field member  150  carried by the actuator housing  141 . The field member  150 , similarly to the actuator housing  141 , has a dimension in a length direction greater than a width direction. Thus, the field member  150  is reciprocally movable in the width direction (i.e., the y-direction). While the movement of the field member  150  is described as being movable in one direction, i.e., a linear haptic actuator, it should be understood that in some embodiments, the field member may be movable in other directions, i.e., an angular haptic actuator, or may be a combination of both a linear and an angular haptic actuator. 
     The field member  150  illustratively includes permanent magnets  151 ,  152  between the first and second coils  144 ,  145 . The permanent magnets  151 ,  152  may be neodymium, for example, and may be positioned in opposing directions with respect to their respective poles. 
     The permanent magnets  151 ,  152  also have a rectangular shape and are aligned along a length of the first and second coils  144 ,  145 . While a pair of rectangular shaped permanent magnets is illustrated, it will be appreciated that there may be any number of permanent magnets having any shape between the first and second coils  145 ,  145 . 
     The field member  150  also includes a mass  157  between the permanent magnets  151 ,  152 . The mass  157  may be tungsten, for example. The mass  157  may be a different material and there may be more than one mass. 
     The haptic actuator  140  also includes respective flexure bearings  160   a ,  160   b  mounting each of first and second sides  153 ,  154  of the field member  150  to be reciprocally movable within the actuator housing  141  responsive to the first and second coils  144 ,  145 . Each flexure bearing  160   a ,  160   b  includes a first end member  161   a ,  161   b , and a second end member  162   a ,  162   b . The second end member  161   a ,  161   b  is coupled to an adjacent side  153 ,  154  of the field member  150 . The second end member  162   a ,  162   b  has a slot  159   b  therein ( FIG. 19 ) receiving the adjacent side  153 ,  154  of the field member  150  therein. 
     Each flexure bearing  160   a ,  160   b  also includes a pair of parallel spaced apart flexible arms  163   a ,  163   b  coupled between the first and second end members  161   a ,  161   b ,  162   a ,  162   b . Each flexure bearing  160   a ,  160   b  may have more than one pair of parallel spaced apart flexible arms  163   a ,  163   b.    
     The pair of parallel spaced apart flexible arms  163   a ,  163   b  illustratively has a non-uniform thickness. Referring briefly to  FIGS. 20, 21, and 22 , in some embodiments, the pair of parallel spaced apart flexible arms  163   a ′ may include an enlarged width medial portion  167   a ′ ( FIG. 20 ), enlarged width end portion&#39;s  168   a ″,  168   b ″ ( FIG. 21 ), and/or one or more openings  169   a ′″ therein ( FIG. 22 ). By having a non-uniform thickness or having an opening therethrough, stress areas, which may be referred to as “stress hot spots,” may be reduced by reducing the amount of material, thereby also increasing displacement. 
     Additionally, it may be desirable for the pair of parallel spaced apart flexible arms  163   a ,  1613   b  to have a thickness that is a few times smaller than the height thereof. This may maintain a reasonable stiffness in directions other than along the motion axis, for example, as will be appreciated by those skilled in the art. More particularly, the pair of parallel spaced apart flexible arms  163   a ,  163   b  may have a thickness that is greater than or equal to half of the distance of the travel thereof (i.e., displacement) to reduce nonlinear stiffening. Reasonable nonlinear stiffening may be particularly advantageous for widening the spectrum, as will be appreciated by those skilled in the art. 
     Each flexure bearing  160   a ,  160   b  also includes an anchor member  164   a ,  164   b  coupled to the first end member  161   a ,  161   b  and coupled to the actuator housing  141 . The anchor member  164   a ,  164   b  is also spaced from the second end member  162   a ,  162   b . The anchor member  164   a ,  164   b  includes a T-shaped anchor body  165   a ,  165   b  and a pair of parallel spaced apart flexure arms  166   a ,  166   b  extending between the anchor body and the first end member  161   a ,  161   b . In some embodiments, the anchor body  165   a ,  165   b  may have another shape. 
     The flexure bearings  160   a ,  160   b  mount each of the first and second sides  153 ,  154  of the field member  150  to be reciprocally movable within the actuator housing  141  responsive to the coils  144 ,  145 . More particularly, the flexure bearings  160   a ,  160   b  move or flex in the direction of the field member  150  and return it to the equilibrium position. Overall flexure or movement of each flexure bearing  160   a ,  160   b  is about 1/10 of the length of the flexure bearing. 
     The haptic actuator  140  advantageously does not include, relative to other types of haptic actuators, shafts and/or bearings to constrain the motion of the mass  157  in a desired direction. Typically, to constrain angular motions, a second shaft or relatively complex stabilization techniques, such as stabilization magnets would be used. However, stabilization magnets may make the haptic actuator more complex, more unreliable, and increasingly expensive. By using the flexure bearings  160   a ,  160   b , movement is generally constrained in every direction except the desired direction, and several relatively expensive parts may be omitted, such as shafts, precise bearings (round/slot), and springs, resulting in a more simple haptic actuator  140 . 
     A method aspect is directed to a method of making a haptic actuator  140 . The method may include positioning at least one coil  144 ,  145  to be carried by an actuator housing  141  and positioning a field member  50  having opposing first and second sides  153 ,  154  within the actuator housing  141 . The method also includes positioning a respective flexure bearing  160   a ,  160   b  to mount each of the first and second sides  153 ,  154  of the field member  150  to be reciprocally movable within the housing responsive to the at least one coil  144 ,  145 . Each flexure bearing  160   a ,  1610   b  includes a first end member  161   a ,  161   b , a second end member  162   a ,  162   b  coupled to an adjacent side of the field member, a pair of parallel spaced apart flexible arms  163   a ,  163   b  coupled between the first and second end members, and an anchor member  164   a ,  164   b  coupled to the first end member and coupled to the actuator housing. 
     Referring now to  FIG. 23  in another embodiment, the haptic actuator  140 ″″ may include permanent magnets  151 ″″,  152 ″″ carried by the housing  141 ″″, and the field member  150 ″″ may include one or more coils  144 ″″,  145 ″″ that cooperate with the permanent magnets. In other words, in contrast to the embodiment described above, the permanent magnets  151 ″″,  152 ″″ are stationary (i.e., carried by the actuator housing  141 ″″) and the coils  144 ″″,  145 ″″, as part of the field member  150 ″″, are moving (i.e., connected to the mass). Of course, there may be any number of coils  144 ″″,  145 ″″ and/or permanent magnets  151 ″″,  152 ″″. 
     Referring now to  FIG. 24 , another embodiment of a haptic actuator  240  is illustrated. Similar to the haptic actuator  140  described above, the haptic actuator  240  includes an actuator housing  241  having a dimension in a length direction greater than a width direction and a coil  244  carried by the actuator housing. The coil  244  illustratively has a loop shape. A second coil, not shown, may be carried by the actuator housing  241  in spaced relation from the coil  244 . Of course, there may be any number of coils  244 , and the coil may have a different shape. 
     The haptic actuator  240  also includes a field member  250  having opposing first and second sides  253 ,  254 . The field member  250 , similarly to the actuator housing  241 , has a dimension in a length direction greater than a width direction. Thus, the field member  250  is reciprocally movable in the width direction (i.e., the y-direction). While the movement of the field member  250  is described as being movable in one direction, i.e., a linear haptic actuator, it should be understood that in some embodiments, the field member may be movable in other directions, i.e., an angular haptic actuator, or may be a combination of both a linear and an angular haptic actuator. 
     The field member  250  includes permanent magnets  251 ,  252  under the coil  244 , or between the first and second coils. The permanent magnets  151 ,  152  may be neodymium, for example, and may be positioned in opposing directions with respect to their respective poles. 
     The permanent magnets  251 ,  252  also have a rectangular shape and are aligned along a length of the coil  244 . While a pair of rectangular shaped permanent magnets is illustrated, it will be appreciated that there may be any number of permanent magnets having any shape. 
     The field member  250  also includes a mass  257  adjacent the permanent magnets  251 ,  252 . The mass  257  may be tungsten, for example. The mass  257  may be a different material and there may be more than one mass. 
     The haptic actuator  240  also includes a flexure bearing  260  mounting each of the first and second sides  253 ,  254  of the field member  250  to be reciprocally movable within the actuator housing  241  responsive to the coil  244 . The flexure bearing  260  includes first and second opposing end members  261   a ,  261   b , and two pairs of parallel spaced apart flexible arms  262   a - 262   b ,  263   a - 263   b  coupled between the first and second end members and spaced apart on opposing sides of the field member  250 . In other embodiments, there may be more than two pairs of parallel spaced apart flexible arms  262   a - 262   b ,  263   a - 263   b , or only one pair. 
     The haptic actuator  240  also includes first and second anchor members  264   a - 264   b ,  265   a - 265   b  each having a rectangular shape and respectively coupling one of each of the two pairs of parallel spaced apart flexible arms  262   a - 262   b ,  263   a - 263   b . The first anchor members  264   a ,  264   b  are illustratively coupled between inner ones of the two pairs of the parallel spaced apart flexible arms and the adjacent portions of the field member  250 . In particular, the first anchor members  264   a ,  264   b  are coupled to a medial portion of the field member  250  and a medial portion of the inner ones  262   b ,  263   b  of the pairs of parallel spaced apart flexible arms. In some embodiments, for example, where there is a single pair of parallel spaced apart flexible arms, there may be a single first anchor. In other embodiments, there may be more than two first anchors  264   a ,  264   b.    
     The second anchor members  265   a ,  265   b  respectively couple the outer ones  262   a - 262   b  of each pair of parallel spaced apart flexible arms to adjacent portions of the actuator housing  241 . In particular, the second anchor members  265   a ,  265   b  are coupled to a medial portion of the actuator housing  141  and a medial portion of the outer ones  263   a ,  262   a  of the pairs of the parallel spaced apart flexible arms respectively. In some embodiments, for example, where there is a single pair of parallel spaced apart flexible arms  262   a - 262   b ,  263   a - 263   b , there may be a single second anchor member. In other embodiments, there may be more than two second anchor members  265   a ,  265   b . Moreover, while the first and second anchor members  264   a - 264   b ,  265   a - 265   b  have been described as being rectangular, in some embodiments the first and second anchor members may be a different shape. 
     Each of the pairs of parallel spaced apart flexible arms  262   a - 262   b ,  263   a - 263   b  illustratively has a non-uniform height. Referring briefly to  FIG. 25 , in some embodiments, each of the pairs of parallel spaced apart flexible arms  263   a ′ may include one or more openings therein  269 ′. By having a non-uniform height or having an opening therethrough, stress areas, which may be referred to as “stress hot spots,” may be reduced by reducing the amount of material, thereby also increasing displacement. 
     A method aspect is directed to a method of making an actuator  240 . The method includes positioning at least one coil  244  to be carried by the actuator housing  241 . The method also includes positioning a field member  250  having opposing first and second sides  253 ,  254  within the housing and positioning the flexure bearing  260  to mount each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil  244 . 
     Referring now to  FIG. 26 , in another embodiment, the haptic actuator  240 ″ may include permanent magnets  251 ″,  252 ″ carried by the housing  241 ″, and the field member  250 ″ may include one or more coils  244 ″ that cooperate with the permanent magnets. In other words, in contrast to the embodiment described above, the permanent magnets  251 ″,  252 ″ are stationary (i.e., carried by the actuator housing  241 ″) and the coil  244 ″, as part of the field member  250 ″ is moving (i.e., connected to the masses  257 ″). Of course, there may be any number of coils and/or permanent magnets. For example, another set of permanent magnets may be carried on opposing sides of the coil  244 ″ than the first and second magnets  251 ″,  252 ″ 
     Referring now to  FIGS. 27 and 28 , another embodiment of a haptic actuator  340  is illustrated. The haptic actuator  340  includes an actuator housing  341  having a dimension in a length direction greater than a width direction and first and second sets of coils  344   a - 344   d ,  345   a - 345   d  are carried by the actuator housing  341  in spaced apart relation by the top and bottom of the actuator housing. The coils  344   a - 344   d ,  345   a - 345   d  each illustratively have a loop shape and each extends along a width of the actuator housing  341 . Each of the first set of coils  344   a - 344   d  is in side-by-side relation. Each of the second set of coils  345   a - 345   d , is also in side-by-side relation. While four first coils  344   a - 344   d  and four second coils  345   a - 345   d  are illustrated, it will be appreciated by those skilled in the art that there may be any number of coils  344   a - 344   d ,  345   a - 345   d , and the coils may have a different shape. 
     The haptic actuator  340  also includes a field member  350  having opposing first and second sides  353 ,  354 . The field member  350 , similarly to the actuator housing  341 , has a dimension in a length direction greater than a width direction. Thus, the field member  350  is reciprocally movable in the length direction (i.e., the x-direction). While the movement of the field member  350  is described as being movable in one direction, i.e., a linear haptic actuator, it should be understood that in some embodiments, the field member may be movable in other directions, i.e., an angular haptic actuator, or may be a combination of both a linear and an angular haptic actuator. 
     The field member  350  includes permanent magnets  351   a - 351   e  between the first and second sets of coils  244   a - 244   d ,  245   a - 345   d . The permanent magnets  351   a - 351   e  may be neodymium, for example, and may be positioned in opposing directions with respect to their respective poles. 
     The permanent magnets  351   a - 351   e  also each have a rectangular shape and are spaced apart along a length of the actuator housing  341 . While rectangular shaped permanent magnets  351   a - 351   e  are illustrated, it will be appreciated that there may be any number of permanent magnets having any shape between the first and second coils  344   a - 344   d ,  345   a - 345   d.    
     The field member  350  also includes masses  357   a - 357   d  between the permanent magnets  351   a - 351   e . The masses  357   a - 357   d  may be tungsten, for example. The masses  357   a - 357   d  may be a different material and there may be more or less than the three masses illustrated. The masses  357   a - 357   d  may be part of a body of the field member  350 , for example members extending across the actuator housing  341 . 
     The haptic actuator  340  also includes a respective flexure bearing  360  mounting each of the first and second sides  353 ,  354  of the field member  350  to be reciprocally movable within the actuator housing  341  responsive to the first and second sets of coils  344   a - 344   d ,  345   a - 345   d . Each flexure bearing  360  includes a first anchor member  361  coupled to an adjacent portion of the actuator housing  341 , more particularly, adjacent an end and a side (i.e., a corner) of the actuator housing. A second anchor member  362  is coupled to an adjacent side of the field member  350  and also adjacent the first side  347   a  of the actuator housing  341 . The first and second anchor members  361 ,  362  are illustratively spaced apart at an initial at-rest position. However, under compression, for example, the first and second anchor members  361 ,  362  may be in contact, as will be appreciated by those skilled in the art. 
     A first flexible arm  363  couples the first and second anchor members  361 ,  362  together. The first flexible arm  363  has a bend therein to define a V-shape, for example. The first flexible arm  363  may have more than one bend therein. 
     Each flexure bearing  360  also includes a third anchor member  364  coupled to an adjacent portion of the actuator housing  341 , illustratively in a corner opposite the first anchor member  361 . A fourth anchor member  365  is coupled to an adjacent side of the field member  350  opposite the second anchor member  362  and also adjacent the second side of the actuator housing  341 . A second flexible arm  366  couples the third and fourth anchor members  364 ,  365  together and has a bend therein, for example, to also define a V-shape. The second flexible arm  366  may have more than one bend therein. 
     A method aspect is directed to a method of making a haptic actuator  340 . The method includes positioning at least one coil  344   a - 344   d  to be carried by an actuator housing  341  and positioning a field member  350  having opposing first and second sides  353 ,  354  within the actuator housing. The method also includes positioning respective flexure bearings  360  to mount each of the first and second sides  353 ,  354  of the field member  350  to be reciprocally movable within the actuator housing responsive to the at least one coil. 
     Referring now to  FIG. 29 , in another embodiment, the haptic actuator  340 ′ may include permanent magnets  351   a ′- 351   e ′ carried by the housing  341 ′, and the field member  350 ′ may include coils  344   a ′- 344   d ′ that cooperate with the permanent magnets. In other words, in contrast to the embodiment described above, the permanent magnets  351   a ′- 351   e ′ are stationary (i.e., carried by the actuator housing  341 ′) and the coils  344   a ′- 344   d ′ as part of the field member  350 ′ are moving (i.e., connected to the masses  357   a ′- 357   d ′). Of course, there may be any number of coils and/or permanent magnets. For example, there may be a second set of permanent magnets carried on an opposing side of the coils  344   a ′- 344   d′.    
     Referring now to  FIGS. 30 and 31 , another embodiment of a haptic actuator  440  is illustrated. The haptic actuator  440  includes an actuator housing  441  having a dimension in a length direction greater than a width direction and first and second sets of coils  444   a - 444   d ,  445   a - 445   d  are carried by the actuator housing in spaced apart relation by the top and bottom of the actuator housing. The coils  444   a - 444   d ,  445   a - 445   d  each illustratively has a loop shape and each extends along a width of the actuator housing  441 . Each of the first set of coils  444   a - 444   d  is in side-by-side relation. Each of the second set of coils  445   a - 445   d , is also in side-by-side relation. While four first coils  444   a - 444   d  and four second coils  445   a - 445   d  are illustrated, it will be appreciated by those skilled in the art that there may be any number of coils, and the coils may have a different shape. 
     The haptic actuator  440  also includes a field member  450  having opposing first and second sides  453 ,  454 . The field member  450 , similarly to the actuator housing  441 , has a dimension in a length direction greater than a width direction. Thus, the field member  450  is reciprocally movable in the length direction (i.e., the x-direction). While the movement of the field member  450  is described as being movable in one direction, i.e., a linear haptic actuator, it should be understood that in some embodiments, the field member may be movable in other directions, i.e., an angular haptic actuator, or may be a combination of both a linear and an angular haptic actuator. 
     The field member  450  includes permanent magnets  451   a - 451   e  between the first and second sets of coils  444   a - 444   d ,  445   a - 445   d . The permanent magnets  451   a - 451   e  may be neodymium, for example, and may be positioned in opposing directions with respect to their respective poles. 
     The permanent magnets  451   a - 451   e  also each have a rectangular shape and are spaced apart along a length of the actuator housing  441 . While rectangular shaped permanent magnets  451   a - 451   e  are illustrated, it will be appreciated that there may be any number of permanent magnets having any shape. 
     The field member  450  also includes a body  456  that includes masses  457   a - 457   d  between the permanent magnets  451   a - 451   e . The masses  457   a - 457   d  may be tungsten, for example. The masses  457   a - 457   d  may be a different material and there may be any number of masses. The field member  450  also includes shafts  458   a ,  458   b  extending outwardly from the body  456  adjacent the first and second ends or sides  453 ,  454 . 
     The haptic actuator  440  also illustratively includes a frame member  470  extending along a first side of the actuator housing  441 . A respective flexure bearing  460  is carried by the frame member  470  and mounts each of the first and second ends  453 ,  454  of the field member  450  to be reciprocally movable within the actuator housing  441  responsive to the first and second coils  444   a - 444   d ,  445   a - 445   d.    
     Each flexure bearing  460  includes a base member  461  coupled to an end of the frame member  470 , and spaced apart flexible arms  462   a ,  462   b  extending outwardly from the base member to a second side of the actuator housing  441 . The spaced apart flexible arms  462   a ,  462   b  are spaced apart at distal ends thereof at an initial at-rest position, and may be parallel at the initial at-rest position. When the flexure bearing  460  is under compression, the spaced apart flexible arms  462   a ,  462   b  may contact one another at the distal ends thereof. The spaced apart flexible arms  462   a ,  462   b  also illustratively include an opening  464   a ,  464   b  therein for receiving respective ones of the shafts  458   a ,  458   b  therein. 
     The haptic actuator  440  also includes a respective guide member  471   a ,  471   b  coupled between a respective end of the actuator housing  441  and a respective flexure bearing  460 . Each guide member  471   a ,  471   b  has an opening  472   a ,  472   b  therein for receiving a respective one of the shafts  458   a ,  458   b . Each guide member  471   a ,  471   b  also has a tapered shape, and more particularly, a width that is decreasing along the width thereof. A thinner or smaller end of each guide member is adjacent the base member of each flexure bearing  460 , for example, to permit the field member  450  to have a larger displacement along the movement or travel path (i.e., the x-axis). As will be appreciated by those skilled in the art, the distal ends of the spaced apart flexible arms slide on the shafts  458   a ,  458   b . In some embodiments, there may be no shafts and openings. 
     A method aspect is directed to a method of making a haptic actuator  440 . The method includes positioning at least one coil  444   a - 444   d ,  445   a - 445   d  to be carried by an actuator housing  410  and positioning a field member  450  having opposing first and second sides  453 ,  454  within the actuator housing. The method also includes positioning the respective flexure bearing  460  to mount each of the first and second sides  453 ,  454  of the field member  450  to be reciprocally movable within the housing responsive to the at least one coil  444   a - 444   d ,  445   a - 445   d.    
     Referring to  FIG. 32 , in another embodiment, the haptic actuator  440 ′ may include first and second sets of permanent magnets  451   a ′- 451   e ′,  452   a ′- 352   e ′ carried by the housing, and the field member  450 ′ may include coils  444   a ′- 444   d ′ that cooperate with the permanent magnets, and more particularly, that are between the first and second sets of permanent magnets. In other words, in contrast to the embodiment described above, the permanent magnets  451   a ′- 451   e ′,  452   a ′- 452   e ′ are stationary (i.e., carried by the actuator housing  441 ′) and the coils  444   a ′- 444   d ′ as part of the field member  450 ′ are moving (i.e., connected to the masses). Of course, there may be any number of coils and/or permanent magnets. 
     Referring now to  FIGS. 33 and 34 , another embodiment of a haptic actuator  540  is illustrated. The haptic actuator  540  may include an actuator housing  541  having a dimension in a length direction greater than a width direction and first and second sets of coils carried by the actuator housing in spaced apart relation, for example, as described above. 
     The haptic actuator  540  also includes a field member  550  having opposing first and second sides  553 ,  554 . The field member  550 , similarly to the actuator housing, has a dimension in a length direction greater than a width direction. Thus, the field member  550  is reciprocally movable in the length direction (i.e., the x-direction). While the movement of the field member  550  is described as being movable in one direction, i.e., a linear haptic actuator, it should be understood that in some embodiments, the field member may be movable in other directions, i.e., an angular haptic actuator, or may be a combination of both a linear and an angular haptic actuator. 
     The field member  550  includes permanent magnets  551   a - 551   f  that are positioned between the first and second sets of coils. The permanent magnets  551   a - 551   f  may be neodymium, for example, and may be positioned in opposing directions with respect to their respective poles. 
     The permanent magnets  551   a - 551   f  also each have a rectangular shape and are spaced apart along a length of the field member  550 , and more particularly, spaced within openings  555   a - 555   f  in the field member  550 . While rectangular shaped permanent magnets  551   a - 551   f  are illustrated, it will be appreciated that there may be any number of permanent magnets having any shape between and the openings  555   a - 555   f  may also have any shape. 
     The field member  550  also includes masses  557   a - 557   e  between the permanent magnets  551   a - 551   f . The masses  557   a - 557   e  are illustratively part of the body of the field member  550 , for example, members extending across the field member and defining the openings  555   a - 555   f . Of course, the masses  557   a - 557   e  can be arranged as described above with respect to the other embodiments. 
     The haptic actuator  540  also includes a respective flexure bearing  560  mounting each of the first and second sides  553 ,  554  of the field member  550  to be reciprocally movable within the actuator housing  541  responsive to the first and second sets of coils. Each flexure bearing  560  includes a flexible member  563  having a wishbone or Y-shape, with two diverging arms  562   a ,  562   b  joined together at proximal ends  575   a ,  575   b . The two diverging arms  562   a ,  562   b  have spaced distal ends  576   a ,  576   b  operatively coupled between adjacent portions of the field member  550  and the housing. 
     The flexible member  563  has a bend  578  therein joining together the two diverging arms  562   a ,  562   b  at the proximal ends  575   a ,  575   b . The bend  578  causes the two diverging arms  562   a ,  562   b  to be spaced apart at the distal ends  576   a ,  576   b . Illustratively, the two diverging arms  562   a ,  562   b  include a parallel portion  577   a ,  577   b  at the distal ends  576   a ,  576   b . In some embodiments, the distal ends  576   a ,  576   b  of the two diverging arms  562   a ,  562   b  may continue to diverge instead of turning or becoming parallel. 
     Referring briefly to  FIG. 35  in another embodiment, the two diverging arms  562   a ′,  552   b ′ are parallel at the proximal ends  575   a ′,  575   b ′ and are coupled together, for example, via a weld joint  579 ′. 
     Referring now to  FIG. 36 , in another embodiment, each flexure bearing  560 ″ may include first and second flexible members  563   a ″,  563   b ″. A respective anchor member  561 ″ is coupled to an adjacent portion of the housing and spaced from an adjacent portion of the field member  550 ″. The anchor member  561 ″ is illustratively L-shaped, having a length aligned along the adjacent portion of the housing. The first and second flexible members  563   a ″,  563   b ″ are coupled between the respective anchor member  561 ″ and the adjacent portions of the field member  550 ″. The first and second flexible members  563   a ″,  563   b ″ are arranged so that the proximal end of the first flexible member  563   a ″ is adjacent the distal end of the second flexible member  563   b″.    
     The table below illustrates exemplary mode shapes and frequencies versus design. Indeed, as will be appreciated by those skilled in the art, the wishbone or Y-shaped design of the flexible member  563  may provide increased stability versus a U or V-shaped flexible member, for example. 
     
       
         
           
               
               
               
            
               
                   
                   
               
               
                   
                 Mode 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 Rocking 
                   
                   
               
               
                   
                 X Mode 
                 Z Mode 
                 Z Mode 
                 Y Mode 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 U/V Shaped 
                 100 Hz 
                 285 Hz 
                 316 Hz 
                 329 Hz 
               
               
                   
                 w/o magnetic 
               
               
                   
                 anti-spring 
               
               
                   
                 Wishbone 
                 100 Hz 
                 381 Hz 
                 382 Hz 
                 405 Hz 
               
               
                   
                 Shaped w/o 
               
               
                   
                 magnetic 
               
               
                   
                 anti-spring 
               
               
                   
                 U/V Shaped 
                 100 Hz 
                 Unstable 
                 128 Hz 
                 329 Hz 
               
               
                   
                 w/magnetic 
               
               
                   
                 anti-spring 
               
               
                   
                 Wishbone 
                 100 Hz 
                 250 Hz 
                 251 Hz 
                 405 Hz 
               
               
                   
                 Shaped 
               
               
                   
                 w/magnetic 
               
               
                   
                 anti-spring 
               
               
                   
                   
               
            
           
         
       
     
     A method aspect is directed to a method of making a haptic actuator  540 . The method includes positioning at least one coil to be carried by an actuator housing and positioning a field member  550  having opposing first and second sides  553 ,  554  within the actuator housing. The method also includes positioning respective flexure bearings  560  to mount each of the first and second sides  553 ,  554  of the field member  550  to be reciprocally movable within the actuator housing responsive to the at least one coil. 
     Referring now to  FIG. 37 , another embodiment of a flexure bearing  660  is illustrated for use with a field member in a haptic actuator as described above. As will be appreciated by those skilled in the art and along the lines as described above, two flexure bearings  660  are typically used in the haptic actuator. 
     Each flexure bearing  660  includes a first anchor member  661  coupled to an adjacent portion of the actuator housing, and more particularly, adjacent an end and a side (i.e., a corner) of the actuator housing. A second anchor member  662  is coupled to an adjacent side of the field member and also adjacent the first side of the actuator housing. The first and second anchor members  661 ,  662  are illustratively spaced apart at an initial at-rest position. However, under compression, for example, the first and second anchor members  661 ,  662  may be in contact, as will be appreciated by those skilled in the art. 
     First and second parallel, spaced apart flexible arms  663   a ,  663   b  each couple the first and second anchor members  661 ,  662  together. The first and second flexible arms  663   a ,  663   b  each has a bend  678   a ,  678   b  therein to define a V-shape, for example. The first and second parallel and spaced apart flexible arms  663   a ,  663   b  may each have more than one bend therein. The first and second parallel, spaced apart flexible arms  663   a ,  663   b  may each have a varying thickness along a length thereof (e.g., from the first anchor member  661  through the bend  678   a ,  678   b  to the second anchor member  662 ). While two parallel, spaced apart flexible arms are illustrated, it will be appreciated that any number of parallel, spaced apart flexible arms  663   a ,  663   b  may couple the first and second anchor members  661 ,  662 . 
     A method aspect is directed to a method of making a haptic actuator. The method includes positioning at least one coil to be carried by an actuator housing and positioning a field member having opposing first and second sides within the actuator housing. The method also includes positioning respective flexure bearings  660  to mount each of the first and second sides of the field member to be reciprocally movable within the actuator housing responsive to the at least one coil. 
     Referring now to  FIG. 38 , in another embodiment, a respective flexure bearing  760  mounts each of the first and second sides of the field member  750  to be reciprocally movable within the housing  741  responsive to at least one coil. The field member  750  and at least one coil are similar to those described above and, thus, need no further discussion herein. 
     Each flexure bearing  760  includes nested flexible members  763   a ,  763   b  (i.e., having a chevron shape) each having a wishbone or Y-shape, with two diverging arms  762   a ,  762   b  joined together at spaced apart proximal ends  775   a ,  775   b . The two diverging arms  762   a ,  762   b  have spaced distal ends  776   a ,  776   b  operatively coupled between adjacent portions of the field member  750  and the housing  741 . The two diverging arms  762   a ,  762   b  are parallel at the proximal ends  775   a ,  775   b  and are coupled together, for example, via a coupling member  781 . The coupling member  781  (e.g., a spacer) may be coupled to the two diverging arms  762   a ,  762   b  of each of the nested flexible members  763   a ,  763   b  by way of weld joints  779 , for example, laser weld joints. The two diverging arms  762   a ,  762   b  of each nested flexible member  763   a ,  763   b  are also parallel to the adjacent nested flexible member. 
     The two diverging arms  762   a ,  762   b  of each of the nested flexible members  763   a ,  763   b  at the distal ends  776   a ,  776   b  may be coupled to the adjacent portions of the field member  750  and housing  741  by an adhesive bond. The respective adjacent portions of the field member  750  and housing  741  are spaced apart along the length of the field member and housing. Of course, the two diverging arms  762   a ,  762   b  of each of the nested flexible members  763   a ,  763   b  at the distal ends  776   a ,  776   b  may be coupled to the adjacent portions of the field member  750  and housing  741  by other coupling techniques, for example, mechanical fasteners, epoxies, etc. 
     Mechanical stops  782   a  are illustratively coupled between the spaced apart distal ends  776   a ,  776   b  of the two diverging arms  762   a ,  762   b  of the nested flexible members  763   a ,  763   b . Mechanical stops  782   b  are also illustratively coupled to the field member  750  adjacent the proximal ends  775   a ,  775   b  of the two diverging arms  762   a ,  762   b  of the flexible members  763   a ,  763   b . The mechanical stops  782   a ,  782   b  may include rubber or other material. There may a different number of mechanical stops  782   a ,  782   b , and the mechanical stops may be positioned elsewhere. In some embodiments, mechanical stops  782   a ,  782   b , may not be included. 
     An exemplary assembly process of the flexure bearing  760  will now be described. A first step may include assembly of the two diverging arms  762   a ,  762   b  of the inner nested flexible member  763   a . The two diverging arms  762   a ,  762   b  or flexure legs and coupling member or linkage are mounted in position by carrier tabs that have notches therein, which are pressed together and welded, for example. 1.3 mm long welding spacing provides a standoff between zones affected by welding heat and high-strain locations of the flexure bearing  760 . 
     The lower or inner nested flexible member and corresponding mounts are assembled and mounted by positioning the lower flexure, inner mount, outer mount, and hard stops in a fixture or bearing by carrier tabs, pressed together and welded. The upper flexure halves are assembled into the flexure assembly or bearing by positioning upper flexure legs or the outer diverging arms in a fixture by carrier tabs, pressed together and welded. It should be noted that there may be an increased failure risk at the welding point during assembly due to a relatively small gap between upper flexure halves and lower flexure halves at the push location due to tight tolerances at small gaps (inner and outer nested flexible members). Relatively tight gaps can be widened by using a profile bar rather than a sheet metal linkage and an offset between upper and lower flexures on inner and outer flexure mounts. The carrier tabs are then removed, by “wiggling” or back and forth motion, flexure glue added, bumpers attached, and a soft stop attached. 
     Referring now to  FIG. 39 , in another embodiment, a first pair of coupling members  781   a ′, for example, in the form of spacers, couple each of the nested flexible members  763   a ′,  763   b ′, and more particularly, the proximal ends  775   a ′,  775   b ′ of the two diverging arms  762   a ′,  762   b ′, together. The first pair of coupling members  781   a ′ may be welded between the two diverging arms of the inner and outer nested flexible members  763   a ′,  763   b ′, for example, via laser welding, to create weld joints  779   b ′ therebetween. Illustratively, there is no coupling member or spacer between proximal ends of the two diverging arms  762   a ′ of the inner nested flexible member  763   a ′, as the two diverging arms are welded together forming a weld joint  779   a ′ therebetween. A second pair of coupling members  781   b ′ are coupled between the distal ends  776   a ′,  776   b ′ of two diverging arms  762   a ′,  762   b ′ of the inner and outer nested flexible members  763   a ′,  763   b′.    
     The spaced apart distal ends  776   a ′,  776   b ′ of the two diverging arms  762   a ′,  762   b ′ of each of the inner and outer nested flexible members  763   a ′,  763   b ′ couple to the same adjacent portion of the housing  741 ′ and field member  750 ′. Since the inner nested flexible member  763   a ′ is spaced from direct contact or coupling with the adjacent portions of the housing and field member  750 ′, it is the second pair of coupling members  781   b ′ that provides the operative coupling to the adjacent portions of the field member and the housing. While not illustrated, mechanical stops may be included. 
     The parallel proximal ends  775   a ′,  775   b ′ of the two diverging arms  762   a ′ of the inner nested flexible member  763   a ′ are illustratively longer in length than their counterparts of the outer nested flexible member  763   b ′. The spaced distal ends  776   a ′,  776   b ′ of the two diverging arms of the outer nested flexible member  763   b ′ are illustratively longer in length than their counterparts of the inner nested flexible member. This arrangement may advantageously achieve a desired spacing between the inner and outer nested flexible members  763   a ′,  763   b′.    
     Referring now briefly to  FIG. 40 , in another embodiment, the proximal and distal ends  775   a ″,  775   b ″,  776   a ″,  776   b ″ of the two diverging arms  762   a ″,  762   b ″ of the inner and outer nested flexible members  763   a ″,  763   b ″ are relatively the same length. The result is that the spacing between the inner and outer nested flexible members  763   a ″,  763   b ″ are determined by the width of the first and second pairs of coupling bodies  781   a ″,  781   b ″. The distal ends  776   a ″,  776   b ″ of each of the inner and outer nested flexible members  763   a ″,  763   b ″ couple the same adjacent portion of the field member  750 ″ and housing  741 ″. 
     Referring to  FIG. 41 , similar to the embodiments described in  FIG. 39 , the parallel proximal ends  775   a ′″,  775   b ′″ of the two diverging arms  762   a ′″ of the inner nested flexible member  763   a ′″ are illustratively longer in length than their counterparts of the outer nested flexible member  763   b ″. There is no coupling member coupling together the proximal ends  775   a ′″,  775   b ′″ of the inner and outer nested flexible members  763   a ′″,  763   b ′″, as the proximal ends of the inner and outer nested flexible members may be coupled by way of a respective weld joints  779 ″. The spaced apart distal ends  776   a ′″,  776   b ′″ of the inner and outer nested flexible members  763   a ′″,  763   b ′″ are operatively coupled to spaced apart adjacent portions of the field member  750 ′″ and housing  741 ′″ via a coupling member  781   b ′″ (inner) and directly (outer) thereto. 
     Referring now to  FIG. 42 , in another embodiment, similar to the embodiment described in  FIG. 38 , a coupling member  781 ″″ couples together the proximal ends  775   a ″″,  775   b ″″ of the inner and outer nested flexible members  763   a ″″,  763   b ″″. The location at which the inner and outer nested flexible members  763   a ″″,  763   b ″″ couple to the coupling member  781 ″″ is spaced apart to create spacing between the inner and outer nested flexible members. For further spacing, for example, the diverging arms  762   b ″″ of the outer nested flexible member  763   b ″″ each have a bend  783   b ″″ therein adjacent the proximal ends  775   b ″″ thereof. Each of the diverging arms  762   a ″″ of the inner nested flexible member  763   a ″″ also, for example, for spacing, have a bend  783   a ″″ therein adjacent the distal ends  776   a ″″ thereof. 
     The tables below shows a comparison between the different, above-described, flexure bearings. 
     
       
         
           
               
               
               
               
               
             
               
                   
               
               
                   
                   
                 Linear X 
                 Linear Y 
                 Linear Z 
               
               
                   
                   
                 Stiffness 
                 Stiffness 
                 Stiffness 
               
               
                 Architecture 
                 Layout 
                 (N/mm) 
                 (N/mm) 
                 (N/mm) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Chevron 
                 Offset 0.20 mm X, 
                 1.3 
                 70 
                 77 
               
               
                 (FIG. 24) 
                 Offset 0.00 mm Y, 
               
               
                   
                 2x linkage 0.10 mm 
               
               
                 Chevron 
                 Offset 0.20 mm X, 
                 1.2 
                 99 
                 77 
               
               
                 (FIG. 23) 
                 Offset 2.20 mm Y, 
               
               
                   
                 2x linkage 0.10 mm 
               
               
                 Chevron 
                 Offset 0.10 mm X, 
                 1.4 
                 99 
                 108 
               
               
                 (FIG. 25) 
                 Offset 2.20 mm Y, 
               
               
                   
                 1x linkage 0.10 mm 
               
               
                 Chevron 
                 Offset 0.00 mm X, 
                 1.5 
                 93 
                 94 
               
               
                 (FIG. 22) 
                 Offset 2.70 mm Y, 
               
               
                   
                 1x linkage 0.20 mm 
               
               
                 Chevron 
                 Offset 0.00 mm X, 
                 1.7 
                 177 
                 71 
               
               
                 Asymmetric 
                 Offset 2.20 mm Y, 
               
               
                 Flexure 
                 1x linkage 0.20 mm 
               
               
                 (FIG. 26) 
               
               
                 Single 
                 One edge 
                 0.6 
                 18 
                 48 
               
               
                 Wishbone 
                 of mounts 
               
               
                 (reference) 
               
               
                 Double 
                 Opposing edges 
                 1.2 
                 35 
                 95 
               
               
                 wishbone 
                 of mounts 
               
               
                 (not nested; 
               
               
                 reference) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
             
               
                   
               
               
                   
                   
                 Bending X 
                 Bending Y 
                 Bending Z 
               
               
                   
                   
                 Stiffness 
                 Stiffness 
                 Stiffness 
               
               
                 Architecture 
                 Layout 
                 (N/mm) 
                 (N/mm) 
                 (N/mm) 
               
               
                   
               
             
            
               
                 Chevron 
                 Offset 0.20 mm X, 
                 1.3 
                 31 
                 18 
               
               
                 (FIG. 24) 
                 Offset 0.00 mm Y, 
               
               
                   
                 2x linkage 0.10 mm 
               
               
                 Chevron 
                 Offset 0.20 mm X, 
                 1.2 
                 63 
                 27 
               
               
                 (FIG. 23) 
                 Offset 2.20 mm Y, 
               
               
                   
                 2x linkage 0.10 mm 
               
               
                 Chevron 
                 Offset 0.10 mm X, 
                 1.4 
                 60 
                 34 
               
               
                 (FIG. 25) 
                 Offset 2.20 mm Y, 
               
               
                   
                 1x linkage 0.10 mm 
               
               
                 Chevron 
                 Offset 0.00 mm X, 
                 1.5 
                 59 
                 26 
               
               
                 (FIG. 22) 
                 Offset 2.70 mm Y, 
               
               
                   
                 1x linkage 0.20 mm 
               
               
                 Chevron 
                 Offset 0.00 mm X, 
                 1.6 
                 95 
                 49 
               
               
                 Asymmetric 
                 Offset 2.20 mm Y, 
               
               
                 Flexure 
                 1x linkage 0.20 mm 
               
               
                 (FIG. 26) 
               
               
                 Single 
                 One edge 
                 0.6 
                 13 
                 17 
               
               
                 Wishbone 
                 of mounts 
               
               
                 (reference) 
               
               
                 Double 
                 Opposing edges 
                 1.2 
                 27 
                 24 
               
               
                 wishbone 
                 of mounts 
               
               
                 (not nested; 
               
               
                 reference) 
               
               
                   
               
            
           
         
       
     
     As will be appreciated by those skilled in the art, a proximal end of a flexible member may bend toward the housing or field member during compression or tension. Moreover, there may be motion in directions other than linear compression or tension, which may be undesirable and result in crashing. A single wishbone shaped flexible member may also be subject to rotation and buckling. 
     The nested flexible members having a wishbone shape advantageously may restrict movement of the proximal end of the flexure member and may restrict movement of the field member in directions other than linear compression and tension. However, the nested flexible members having a wishbone shape may be subject to increased x-direction, y-direction, and z-direction drop and fatigue risk relative to other types of flexible members. Simulated comparisons between a flexure bearing having nested flexible members each having a wishbone shape relative to a U/V shape flexure bearing are below in the tables. 
     
       
         
           
               
               
               
               
               
             
               
                   
                   
               
               
                   
                   
                   
                   
                 Nested Wishbone 
               
               
                   
                   
                   
                 U/V Shaped 
                 Flexure 
               
               
                   
                 Parameter 
                   
                 Flexure 
                 (% change) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 X-Translation 
                 133 
                 Hz 
                  −5% 
               
               
                   
                 Frequency (X) 
               
               
                   
                 Y-Translation 
                 511 
                 Hz 
                 +53% 
               
               
                   
                 Frequency (Y) 
               
               
                   
                 Z-Bending 
                 436 
                 Hz 
                 +16% 
               
               
                   
                 Frequency (Z) 
                   
                   
                 (w/anti-spring) 
               
               
                   
                 XY-Rotation 
                 732 
                 Hz 
                 +34% 
               
               
                   
                 Frequency (ZZ) 
               
               
                   
                 YZ-Rotation 
                 1027 
                 Hz 
                 −18% 
               
               
                   
                 Frequency (XX) 
                   
                   
                 (w/anti-spring) 
               
               
                   
                 2 nd  Z-Bending 
                 1193 
                 Hz 
                 +46% 
               
               
                   
                 Frequency (YY) 
               
               
                   
                 3 rd  Z-Bending 
                 2402 
                 Hz 
                 +0.5%  
               
               
                   
                 Frequency 
               
               
                   
                 XY-Flexure 
                 3907 
                 Hz 
                 +189%  
               
               
                   
                 Frequency 
               
               
                   
                 X-Drop/(Nominal) 
                 0.65 (0.42) 
                 GPa 
                 +17% 
               
               
                   
                 Peak Stress 
               
            
           
           
               
               
               
               
            
               
                   
                 Z-Drop Peak 
                 2.42 
                 +15% 
               
               
                   
                 Stress 
               
               
                   
                   
               
            
           
         
       
     
     Indeed, while various embodiments have been described with respect to various flexure bearing configurations and coil and permanent magnet configurations, it should be understood that elements from any of the embodiments may be used with any of the other embodiments. For example, a given haptic actuator may include more than one type of flexure bearing as described herein, for example, to not only allow movement of the field member, but return it to an equilibrium position. 
     A haptic actuator comprises a housing, at least one coil carried by the housing, a field member having opposing first and second sides, and a respective flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing comprises a plurality of nested flexible members each having a wishbone shape with two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing. 
     The haptic actuator further comprises a coupling member coupling together proximal ends of the plurality of nested flexible members. 
     The two diverging arms of a given flexible member are parallel with the two diverging arms of an adjacent nested flexible member of the plurality thereof. 
     Each of the two diverging arms of each of the plurality of nested flexible members has a bend therein. 
     The two diverging arms include respective portions being spaced apart adjacent the proximal ends. 
     The two diverging arms are coupled together at the proximal ends. 
     Each flexible member comprises a weld joint at the proximal ends. 
     The haptic actuator further comprises at least one adhesive bond coupling each flexible member to adjacent portions of the field member. 
     The haptic actuator further comprises a mechanical stop coupled between the spaced distal ends of a given flexible member. 
     The haptic actuator further comprises a mechanical stop coupled to the field member adjacent the proximal ends of the two diverging arms of a given flexible member. 
     An electronic device comprises a housing, wireless communications circuitry carried by the housing, and a haptic actuator carried by the housing. The haptic actuator comprises an actuator housing, at least one coil carried by the housing, a field member having opposing first and second sides, and a respective flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing comprises a plurality of nested flexible members each having a wishbone shape with two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing. The electronic device comprises a controller coupled to the wireless communications circuitry and the haptic actuator and configured to perform at least one wireless communications function and selectively operate the haptic actuator. 
     The haptic actuator further comprises a coupling member coupling together proximal ends of the plurality of nested flexible members. 
     The two diverging arms of a given flexible member are parallel with the two diverging arms of an adjacent nested flexible member of the plurality thereof. 
     Each of the two diverging arms of each of the plurality of nested flexible members has a bend therein. 
     The two diverging arms include respective portions being spaced apart adjacent the proximal ends. 
     A method of making a haptic actuator comprises positioning a respective flexure bearing to mount each of first and second sides of a field member to be reciprocally movable within a housing responsive to at least one coil, each flexure bearing comprising a plurality of nested flexible members each having a wishbone shape with two diverging arms joined together at proximal ends and having spaced distal ends operatively coupled between adjacent portions of the field member and the housing. 
     Each respective flexure bearing comprises a coupling member coupling together proximal ends of the plurality of nested flexible members. 
     The two diverging arms of a given flexible member are parallel with the two diverging arms of an adjacent nested flexible member of the plurality thereof. 
     Each of the two diverging arms of each of the plurality of nested flexible members has a bend therein. 
     The two diverging arms include respective portions being spaced apart adjacent the proximal ends. 
     Referring now additionally to  FIGS. 43-44 , in another embodiment the haptic actuator  1040  includes an actuator housing  1041 . The actuator housing  1041  illustratively has a dimension in a length direction greater than a width direction. The actuator housing  1041  may include ferritic material in portions of or all of the actuator housing. For example, the top and bottom of the actuator housing  1041  may be ferritic. Of course other and/or additional portions of the actuator housing  1041  may be ferritic. The use of ferritic material in the actuator housing  1041  may improve performance, for example. 
     The haptic actuator  1040  also includes first and second coils  1044 ,  1045  carried by the actuator housing  1041 , for example, the top and the bottom, respectively. The first and second coils  1044 ,  1045  may each have a loop shape or “racetrack” shape and are aligned in a stacked relation and spaced apart. There may be any number of first and second coils  1044 ,  1045 , as will be appreciated by those skilled in the art. Moreover, in some embodiments, the first and/or second coils  1044 ,  1045  may be carried by the actuator housing around an exterior thereof, i.e., a circumferential voice coil. 
     The haptic actuator  1040  also includes a field member  1050  carried by the actuator housing  1041 . The field member  1050 , similarly to the actuator housing  1041 , has a dimension in a length direction greater than a width direction. Thus, the field member  1050  is reciprocally movable in the width direction (i.e., the y-direction). While the movement of the field member  1050  is described as being movable in one direction, i.e., a linear haptic actuator, it should be understood that in some embodiments, the field member may be movable in other directions, i.e., an angular haptic actuator, or may be a combination of both a linear and an angular haptic actuator. 
     The field member  1050  illustratively includes permanent magnets  1051   a - 1051   c  between the first and second coils  1044 ,  1045 . The permanent magnets  1501   a - 1051   c  may be neodymium, for example, and may be positioned in opposing directions with respect to their respective poles. 
     The permanent magnets  1051   a - 1501   c  are aligned with the first and second coils  1044 ,  1045 . While three permanent magnets  1051   a - 1051   c  are illustrated, it will be appreciated that there may be any number of permanent magnets having any shape between the first and second coils  1044 ,  1045 . The permanent magnets  1051   a - 1051   c  may be arranged in a Halbach array, for example. Referring briefly to  FIG. 45 , in some embodiments, the position of the coils  1044 ′,  1045 ′ and the permanent magnets  1051   a ′- 1051   c ′ may be reversed. In other words, the first and second coils  1044 ′,  1045 ′ may be carried by or part of the field member  1050 ′, while the permanent magnets  1051   a ′- 1051   c ′ are stationary or carried by the actuator housing  1041 ′ (i.e., a moving coil configuration). 
     The haptic actuator  1040  also includes respective flexure bearings  1060  mounting each of first and second sides  1053 ,  1054  of the field member  1050  to be reciprocally movable within the actuator housing  1041  responsive to the first and second coils  1044 ,  1045 . Each flexure bearing  1060  includes series coupled arms  1061   a - 1061   c . While three arms  1061   a - 1061   c  are illustrated, it will be appreciated that there may be more than three arms. A first arm  1061   a  has a fixed end  1062   a  coupled to the actuator housing  1041 , for example, by way of a first anchor member  1071 . 
     A last arm  1061   c  has a fixed end  1063   a  this is coupled to the field member  1050 . The last arm  1061   c  may be coupled to the field member  1050  by way of a second anchor member  1072 , for example. The first and last arms  1061   a ,  1061   c  may be coupled, respectively, to the actuator housing  1041  by other and/or additional interface members or directly without any anchor or other member. 
     Each flexure bearing  1060  also includes an intermediate arm  1061   b  coupled between free ends  1062   b ,  1063   b  of the first and last arms  1061   a ,  1061   c . The intermediate arm  1061   b  has opposing free ends by way of coupling to the free ends  1062   b ,  1063   b  of the first and last arms  1061   a ,  1061   c . Illustratively, the flexure bearing  1060  has first and second bends  1064   a ,  1064   b  therein at the transition between the first and intermediate arms  1061   a ,  1061   b  and the last and intermediate arms  1061   c ,  1061   b , respectively. In some embodiments, the transition between adjacent series coupled arms may not be in the form of a bend, but instead may include spacers, weld joints, and/or other transitions. As will be appreciated by those skilled in the art, the flexure bearing  1060  may include additional arms, for example, additional intermediate arms that would be series coupled. 
     The first, intermediate, and last arms  1061   a - 1061   c  may include steel, titanium, and/or copper. The first, intermediate, and last arms  1061   a - 1061   c  may include other and/or additional materials. 
     Referring now to  FIG. 46 , each arm  1061   a ″- 1061   c ″ has a blade shape having a length between respective ends, a thickness, and height with a varying profile defining a reduced sized medial portion  1065   a ″- 1065   c ″. The varying profile that defines the reduced sized medial portions  1065   a ″- 1065   c ″ illustratively is in the form of a curve between the ends. 
     Each flexure bearing  1060 ″ illustratively does not include a bend. Each arm  1061   a ″- 1061   c ″ is coupled to the adjacent arm using a spacer member  1066   a ″,  1066   b ″ adjacent the ends. More particularly, a respective spacer member  1066   a ″,  1066   b ″ is between adjacent ends of the intermediate arm  1061   b ″ and the first arm  1061   a ″, and the intermediate arm and the last arm  1061   c ″. A weld joint joins  1067   a ″,  1067   b ″ together each respective spacer member  1066   a ″,  1066   b ″ with the intermediate and first arms  1061   b ″,  1061   a ″, and intermediate and last arms  1061   c″.    
     The reduced size medial portion  1065   a ″- 1065   c ″ may advantageously distribute stresses over each arm  1061   a ″- 1061   c ″ thus constituting an improved use of the material. In contrast, in a flat arm, or uniform size arm, stresses are mostly distributed along edges of the arms. More particularly, each arm is patterned (e.g. stamped) with the illustrated curved pattern defining the reduced size medial portion  1065   a ″- 1065   c ″ to distribute the stress more uniformly over the length of the arms and away from the weld joints to reduce the risk of fatigue and improve the flexure travel range at low frequencies by up to 1.5 times. 
     Referring now to  FIGS. 47-51 , in another embodiment, each arm  1061   a ′″- 1061   c ′″ includes first and second parallel and spaced apart blades  1068   a ′″,  1068   b ′″. Each arm  1061   a ′″- 1061   c ′″ has spacer members  1074 ′″ between the first and second parallel and spaced apart blades  1068   a ′″,  1068   b ′″ at the ends thereof (e.g., at both free and fixed ends). Respective weld joints  1075 ′″ join together each of the plurality of spacer members  1074 ′″ and adjacent portions of the spaced apart blades  1068   a ′″- 1068   c ′″. Further spacer members  1078 ′″ and respective weld joints  1079 ′″ join together the first and intermediate arms  1061   a ′″,  1061   b ′″, and the last and intermediate arms  1061   c ′″,  1061   b ′″ at ends thereof. 
     Referring briefly to  FIGS. 52 and 53  in another embodiment, each arm  1061   a ″″- 1061   c ″″ may include a filler body  1081 ″″ between the first and second parallel and spaced apart blades  1068   a ″″,  1068   b ″″. The filler body  1081 ″″ may include a relatively soft material or bumper material, for example, an elastic material, silicone, and/or foam and follows the contour of the first and second blades  1068   a ″″,  1068   b ″″. The filler body  1081 ″″ may act as a crash stop, for example, to reduce failure in an event of a crash. Of course, the filler body  1081 ″″ may be another and/or include other materials, for example. As will be appreciated by those skilled in the art, the flexure bearing  1060 ″″, at a relatively low frequency, may not see between the filler body  1081 ″″, but upon a drop of the haptic actuator or at a relatively high frequency, the filler material provides increased protection against a failure. In some embodiments, the first and second spaced apart blades  1068   a ″″,  1068   b ″″ may be covered, partially or completely, in a bumper material. 
     As will be appreciated by those skilled in the art, by adding to the number of arms in a flexure bearing (e.g., going from two to three), the displacement and load may be distributed over more arms and reduce, e.g. proportionally, the fatigue risk for a same travel range. Furthermore, increasing the number of arms generally may increase the thickness of the flexure bearing for a given stiffness. Thus, the flexure bearings  1060 ,  1060 ″,  1060 ′″,  1060 ″″ described herein may be significantly more bulky than one with two arms, for example, for the same stiffness. 
     Increasing the number of arms may deteriorate the lateral stiffness of the flexure bearing especially in Y-axis and Z-axis directions, which may be considered the main tradeoff of the flexure bearings described herein as opposed to, for example, a two-arm V-shaped flexure bearing. The first and second parallel and spaced apart blades  1068   a ′″,  1068   b ′″ of each flexure arm  1061   a ′″- 1061   c ′″ improve the lateral stiffness. Moreover, torsion, for example, at the free ends  1062   b ′″,  1063   b ′″ may be reduced, thus improving the actuator particularly in its higher modes. Frequency separation between a first mode (desired LRA motion in x-axis direction) and higher modes may also increase. 
     Still further, the free ends  1062   b ′″,  1063   b ′″ of the arms  1061   a ′″,  1061   c ′″ may act as a robust crash stop and may be used in addition to other crash stops that may be positioned along and/or adjacent the arms. Thus the risk of flexure deformation in the x-axis direction may be reduced, for example, during a drop. 
     A method aspect is directed to a method of making a haptic actuator  1040 . The method includes positioning a respective flexure bearing  1060  to mount each of first and second sides  1053 ,  1054  of a field member  1050  to be reciprocally movable within a housing  1041  responsive to at least one coil  1044 ,  1045 . Each flexure bearing  1060  includes series coupled arms  1061   a - 1061   c , with a first arm  1061   a  having fixed end  1062   a  coupled to the housing  1041 , a last arm  1061   c  having a fixed end  1063   a  coupled to the field member  1050 , and an intermediate arm  1061   b  coupled between free ends  1062   b ,  1063   b  of the first and last arms. 
     A haptic actuator comprises a housing, at least one coil carried by the housing, a field member having opposing first and second sides, and a respective flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing comprises a plurality of series coupled arms, with a first arm having a fixed end coupled to the housing, a last arm having a fixed end coupled to the field member, and at least one intermediate arm coupled between free ends of the first and last arms. 
     Each arm has a blade shape having a length between respective ends, a thickness, and height with a varying profile defining a reduced sized medial portion. 
     Each flexure bearing further comprises a respective spacer member between adjacent ends of the at least one intermediate arm and the first arm, and the at least one intermediate arm and the last arm. 
     The haptic actuator further comprises a weld joint joining together the respective spacer member with the at least one intermediate and first arms, and the at least one intermediate and last arms. 
     Each arm comprises first and second parallel and spaced apart blades. 
     Each arm comprises a plurality of spacer members between the first and second parallel and spaced apart blades. 
     The haptic actuator further comprises respective weld joints joining together each of the plurality of spacer members and adjacent portions of the spaced apart blades. 
     Each arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     Each flexure bearing has a plurality of bends therein. 
     Each flexure bearing further comprises a first anchor member between the housing and first arm. 
     Each flexure bearing further comprises a second anchor member between the field member and last arm. 
     An electronic device comprises a housing, wireless communications circuitry carried by the housing, and a haptic actuator carried by the housing. The haptic actuator comprises an actuator housing, at least one coil carried by the housing, a field member having opposing first and second sides, and a respective flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing comprises a plurality of series coupled arms, with a first arm having a fixed end coupled to the housing, a last arm having a fixed end coupled to the field member, and at least one intermediate arm coupled between free ends of the first and last arms. The electronic device comprises a controller coupled to the wireless communications circuitry and the haptic actuator and configured to perform at least one wireless communications function and selectively operating the haptic actuator. 
     Each arm has a blade shape having a length between respective ends, a thickness, and height with a varying profile defining a reduced sized medial portion. 
     Each flexure bearing further comprises a respective spacer member between adjacent ends of the at least one intermediate arm and the first arm, and the at least one intermediate arm and the last arm. 
     Each arm comprises first and second parallel and spaced apart blades. 
     Each arm comprises a plurality of spacer members between the first and second parallel and spaced apart blades. 
     Each arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     A method of making a haptic actuator comprises positioning a respective flexure bearing to mount each of first and second sides of a field member to be reciprocally movable within a housing responsive to at least one coil, each flexure bearing comprising a plurality of series coupled arms, with a first arm having a fixed end coupled to the housing, a last arm having a fixed end coupled to the field member, and at least one intermediate arm coupled between free ends of the first and last arms. 
     Each arm has a blade shape having a length between respective ends, a thickness, and height with a varying profile defining a reduced sized medial portion. 
     Each flexure bearing further comprises a respective spacer member between the at least one intermediate arm and the first arm, and the at least one intermediate arm and the last arm. 
     Each arm comprises first and second parallel and spaced apart blades. 
     Each arm comprises a plurality of spacer members between the first and second parallel and spaced apart blades. 
     Each arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     A haptic actuator comprises a housing, at least one permanent magnet carried by the housing, a field member having opposing first and second sides and comprising at least one coil cooperating with the at least one permanent magnet, and a respective flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing comprises a plurality of series coupled arms, with a first arm having a fixed end coupled to the housing, a last arm having a fixed end coupled to the field member, and at least one intermediate arm coupled between free ends of the first and last arms. 
     Each arm has a blade shape having a length between respective ends, a thickness, and height with a varying profile defining a reduced sized medial portion. 
     Each flexure bearing further comprises a respective spacer member between adjacent ends of the at least one intermediate arm and the first arm, and the at least one intermediate arm and the last arm. 
     The haptic actuator further comprises a weld joint joining together the respective spacer member with the at least one intermediate and first arms, and the at least one intermediate and last arms. 
     Each arm comprises first and second parallel and spaced apart blades. 
     Each arm comprises a plurality of spacer members between the first and second parallel and spaced apart blades. 
     The haptic actuator further comprises respective weld joints joining together each of the plurality of spacer members and adjacent portions of the spaced apart blades. 
     Each arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     Each flexure bearing has a plurality of bends therein. 
     Each flexure bearing further comprises a first anchor member between the housing and first arm. 
     Each flexure bearing further comprises a second anchor member between the field member and last arm. 
     An electronic device comprises a housing, wireless communications circuitry carried by the housing, and a haptic actuator carried by the housing. The haptic actuator comprises an actuator housing, at least one permanent magnet carried by the housing, a field member having opposing first and second sides and comprising at least one coil cooperating with the at least one permanent magnet, and a respective flexure bearing mounting each of the first and second sides of the field member to be reciprocally movable within the housing responsive to the at least one coil. Each flexure bearing comprises a plurality of series coupled arms, with a first arm having a fixed end coupled to the housing, a last arm having a fixed end coupled to the field member, and at least one intermediate arm coupled between free ends of the first and last arms. The electronic device comprises a controller coupled to the wireless communications circuitry and the haptic actuator and configured to perform at least one wireless communications function and selectively operating the haptic actuator. 
     Each arm has a blade shape having a length between respective ends, a thickness, and height with a varying profile defining a reduced sized medial portion. 
     Each flexure bearing further comprises a respective spacer member between adjacent ends of the at least one intermediate arm and the first arm, and the at least one intermediate arm and the last arm. 
     Each arm comprises first and second parallel and spaced apart blades. 
     Each arm comprises a plurality of spacer members between the first and second parallel and spaced apart blades. 
     Each arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     A method of making a haptic actuator comprises positioning a respective flexure bearing to mount each of first and second sides of a field member comprising at least one coil to be reciprocally movable within a housing responsive to the at least one coil, the housing carrying at least one permanent magnet cooperating with the at least one coil, each flexure bearing comprising a plurality of series coupled arms, with a first arm having a fixed end coupled to the housing, a last arm having a fixed end coupled to the field member, and at least one intermediate arm coupled between free ends of the first and last arms. 
     Each arm has a blade shape having a length between respective ends, a thickness, and height with a varying profile defining a reduced sized medial portion. 
     Each flexure bearing further comprises a respective spacer member between the at least one intermediate arm and the first arm, and the at least one intermediate arm and the last arm. 
     Each arm comprises first and second parallel and spaced apart blades. 
     Each arm comprises a plurality of spacer members between the first and second parallel and spaced apart blades. 
     Each arm further comprises a filler body between the first and second parallel and spaced apart blades. 
     While several different embodiments have been described, it should be appreciated that elements in any one embodiment may be used with any other element or elements from any of the other embodiments. Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.

Metadata:
Filing Date: 20170731
Publication Date: 20220419
Grant Date: 20220419
Priority Date: 20170216
Inventors: HAJATI, ARMAN
HARRISON, JERE C.
LAW, JASON C.
AMES, LOGAN M.
Assignee: APPLE INC
CPC Classifications: [{"code": "A63F13/25", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0481", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0481", "inventive": true, "first": false, "tree": "[]"}, {"code": "A63F13/25", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 59579942