Patent Publication Number: US-2009229113-A1

Title: Actuator assembly

Description:
FIELD OF THE INVENTION 
     The present invention can relate to methods and apparatus for providing robust yet thin actuators for use with electronic devices. 
     BACKGROUND OF THE INVENTION 
     As many consumer electronic devices increasingly small, many of the mechanical and structural components inside the devices also become small. For example, small structural mechanisms, like actuators often need to be thin, but also be rigid and have sufficient structural integrity. However, as parts become smaller, it can become more difficult to manufacture the parts. 
     Some electronic devices have sliders, or actuators, that provide interfaces for a user to mechanically actuate a component disposed within the device. For example, Apple Computer, Inc. of Cupertino, Calif. markets a line of iPod™ devices that have hold-switch sliders. A hold-switch slider can allow a user to actuate an electronic hold-switch component located within the housing of the device. When activated, the electronic hold-switch component—i.e., the component that communicates with the electrical circuit—can lock down the iPod™ to prevent a user from unintentionally changing the current operational state of the iPod™. 
     It may be desirable to design the hold-switch slider to be robust to withstand a large number of cycles. However, it also is desirable to design hold-switch sliders to be thin so that they may sit in very tight areas of the iPod™ devices and yet be easily manufacturable so that the hold-switch slider can be mass produced. 
     In some electronic devices, actuators that allow a user to actuate an electronic component located within the device may have a single thickness. A single thickness is generally easy to manufacture, but not necessarily capable of withstanding repeated loads. That is, over time the mating region of the actuator may wear more quickly because the load on the actuator may not be distributed over a large region. 
     In other devices, actuators may weld two pieces together to thicken the mating region. However, because the mating region of the actuator can be very small, the actuator may be difficult to manufacture because of the difficulty involved in fixturing and welding two small pieces. 
     SUMMARY OF THE INVENTION 
     One embodiment of the present invention is a mechanical actuator having an interface portion and an actuation portion that is thicker than the interface portion. The interface portion can provide an interface for a user to slide the actuator. The actuation portion can incorporate a feature that mates with an electronic component within an electronic device. When a user moves the interface portion, that motion can be translated by the actuation portion to actuate the electronic component. 
     In one embodiment of the present invention, the actuation portion may have a thickness that at least is double that of the interface portion. The actuator may be manufactured by folding over a portion of the actuator to create the double thickness. 
     A method of forming a hold-switch actuator according to the invention may include stamping a hold-switch slider form. Then the method may include folding a portion of the form to create a double thickness portion of the form. The method may also include stamping a cutout from the double thickness portion of the form. In one aspect of the invention, the cutout may mate with a protuberance, when actuated, directly actuates an electronic circuit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects and advantages of the present invention will be apparent upon consideration of the following detailed description, taken in conjunction with accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
         FIG. 1  illustrates an exemplary electronic device that can include the present invention; 
         FIGS. 2A-C  illustrate an actuator assembly in accordance with one embodiment of the present invention; 
         FIGS. 3A-C  illustrate a component of the actuator assembly of  FIGS. 2A-C  in accordance with one embodiment of the present invention; 
         FIG. 4  provides a flowchart of steps for manufacturing the component of  FIGS. 3A-C  in accordance with one embodiment of the present invention; and 
         FIGS. 5A-C  illustrate engagement of components of the actuator assembly of  FIGS. 2A-C  in accordance with one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates an exemplary electronic device that can incorporate the present invention. Electronic device  10  can be any electronic device, including any portable, mobile, hand-held, or miniature consumer electronic device having an actuator that provides an interface for a user to mechanically actuate a component disposed within the device. Illustrative electronic devices can include, but are not limited to, music players, video players, still image players, game players, other media players, music recorders, video recorders, cameras, other media recorders, radios, medical equipment, calculators, cellular phones, other wireless communication devices, personal digital assistances, programmable remote controls, pagers, laptop computers, or combinations thereof. 
     Miniature electronic devices have a form factor that is generally smaller than that of hand-held devices. Illustrative miniature electronic devices can include, but are not limited to, watches, rings, necklaces, belts, accessories for belts, headsets, accessories for shoes, virtual reality devices, other wearable electronics, accessories for sporting equipment, accessories for fitness equipment, or combinations thereof. 
     In one embodiment of the present invention, electronic device  10  can be iPod™. Electronic device  10  can include housing  12 , accessory connector  14 , display  16 , user input component  18 , and hold-switch  20 . Accessory connector  14  can mechanically and electrically couple to a complementary connector from an accessory device, e.g., an accessory similar to those compatible with an iPod™. Accessories can include a computer, a printer, a display, speakers, audio system, headphones, a dock, a lanyard, or a combination thereof. User input component  18  can provide an interface for a user to input data into electronic device  10 , e.g., a scroll wheel similar to that used by an iPod™. The scroll wheel can include one or more buttons  18   b  that may permit a user to select software entries and touchpad  18   a  that may permit a user to scroll through software menus. In alternative embodiments, user input component  18  may include, for example, one or more buttons, a touchpad, a touchscreen display, electronics for accepting voice commands, antennas, infra red ports, or combinations thereof. 
     Hold-switch  20  can allow a user to actuate an electrical hold-switch component located within housing  12  of the device. When actuated, the electrical hold-switch component can lock down the electronic device to prevent a user from unintentionally changing the current operational state of the device. 
     To withstand the large number of cycles to which hold-switch  20  may be subjected, it may be desirable to design a robust hold-switch. It also may be desirable to design the hold-switch to be sufficiently thin to be placed in a very small space of the electronic device and to be easily manufacturable so that the hold-switch can be mass produced. 
     The present invention can include a hold-switch that can be disposed within an area having tight space constraints and can distribute loads applied to the slide over a large surface area. In some embodiments, The hold-switch of the present invention also can be easily manufactured. 
       FIGS. 2A-C  illustrate hold-switch assembly  22  of the present invention. Hold-switch assembly  22  can include hold-switch user interface  24 , faceplate  26 , hold-switch slider  28  (also referred to herein as a hold-switch actuator), electrical hold-switch  30 , and hold-switch support  32 . Hold-switch support  32  can provide a base from which the other components of hold-switch assembly  22  can be mounted. 
     Hold-switch user interface  24  can be disposed on an outer surface of housing  12  to provide an interface for the user to actuate the hold-switch. Hold-switch user interface  24  can include one or more protuberances  34  that may be configured to mechanically engage slots  36  in hold-switch slider  28 . When a user slides user interface  24  along track  38  in faceplate  26 , the motion is translated to hold-switch slider  28 . 
     Faceplate  26  may include slot  38  through which protuberances  34  of hold-switch user interface  24  may be disposed to engage hold-switch slider  28 . Slot  38  may act as a track that constrains the motion of hold-switch user interface  24  in one direction. When hold-switch interface  24  is disposed at one end of slot  38 , electrical hold-switch  30  can transmit a signal or signals that indicate one state (e.g., lock down the electronic device). When hold-switch interface  24  is disposed at the other end of slot  38 , electrical hold-switch  30  can transmit a signal or signals that indicate a second state (e.g., unlock the electronic device). 
     In alternative embodiments of the present invention, the hold-switch can indicate additional states. For example, when hold-switch interface  24  is disposed at the middle of slot  38 , electrical hold-switch  30  can transmit a signal or signals that indicate a third state (e.g., permit the user to change predetermined parameters of the electronic device while other predetermined parameters are locked down). 
     In one embodiment of hold-switch interface  24  having multiple states, slot  30  can also include various ridges or other assembly that provides tactile feedback when the slider is moved from one position to another. Such an assembly may be critical in providing the user with the information that the hold-switch interface is in the middle position. In the absence of such tactile feedback, it may be difficult to determine whether the hold-switch interface is in the middle state. In an additional embodiment of the invention, such tactile feedback may be implemented with respect to protuberance  31  of electrical hold-switch  30  (see, e.g., FIGS.  2 A and  5 A-B). 
     In alternative embodiments of the present invention, slot  38  may have another configuration (e.g., an “x” configuration) that permits hold-switch user interface  24  to move in more than one direction. This may be useful when the hold or lock function has more than two states that a user can set using a switch or when hold-switch also serves another function of the electronic device that also has multiple states that a user can set using a switch. 
       FIGS. 3A-C  illustrate enlarged views of hold-switch slider  28 . Hold-switch slider  28  can have interface portion  40  coupled to actuation portion  42 . Interface portion  40  may include slots  36  configured to mechanically engage protuberances  34  of hold-switch user interface  24 . Actuation portion  42  can include first layer  42   a , second layer  42   b , and cutout  44  that may be configured to mechanically engage protuberance  31  of electrical hold-switch  30  (see, e.g., FIGS.  2 A and  5 A-B). Cutout  44  may be tightly toleranced so that the cutout can mate properly with electrical hold-switch  30 . A precise fit between cutout  44  and electrical hold-switch  30  may be important to provide smooth movement of hold-switch user interface  24  when a user actuates the interface. 
     When a user slides user interface  24 , the motion is translated by interface portion  40  to actuation portion  42  of hold-switch slider  28 . Cutout  44  then can actuate electrical hold-switch  30 . In one embodiment of the present invention, actuation portion  42  may have approximately double the thickness of interface portion  40  to impart greater strength and thickness thereto. This can permit contact force between the hold-switch slider and the electrical hold-switch to be distributed over a larger surface area. The reduced stress can reduce wear on the part. Increased thickness of actuation portion  42  also can ensure that the hold-switch slide reliably engages the electrical hold-switch even while maintaining a thin profile. In one embodiment of the present invention, the thickness of interface portion  40  may be between about 0.20 mm and about 0.60 mm and the thickness of actuator portion  42  may be approximately double the thickness of the interface portion. 
     In  FIGS. 2A-C , electrical hold-switch  30  is illustrated on a portion of flexible printed circuit (FPC)  33 . Flexible circuit  33  can electrically couple electrical hold-switch  30  to a circuit board (not shown). Protuberance  31  of electrical hold-switch  30  may be configured to mechanically engage cutout  44  of hold-switch slider  28 . When protuberance  31  is actuated (e.g., by sliding along an axis), a signal can be transmitted by the electrical hold-switch to a circuit board (not shown) to lock down the electronic device. This can prevent a user from accidentally changing the current operational state of the device. 
       FIG. 4  provides an exemplary flowchart of steps for manufacturing hold-switch slider  28 . To manufacture hold-switch slider  28  in large quantities, the slider may first be stamped out of a rigid material (step  46 ), such as stainless steel. The stamping device can stamp the material so that the entire slider, including first and second layers  42   a  and  42   b  of actuation portion  42 , is one continuous co-planar piece. To produce the increased thickness in actuation portion  42 , second layer  42   b  can be folded next to first layer  42   a  (step  48 ), thereby doubling the thickness of actuation component  42 . 
     In embodiment of the present invention, cutout  44  then can be stamped out from the actuation portion through both first and second layers  42   a,b  create a clean match between the two layers (step  50 ). In alternative embodiments, the cutout can be stamped into the slider in step  46  when the slider initially is stamped out of a rigid material or milled from the actuation portion. 
       FIGS. 5A-C  illustrate mechanical engagement of hold-switch slider  28  to electrical hold-switch  30 . In one embodiment of the present invention, protuberance  31  of electrical hold-switch  30  may have a thickness that is less than that of actuation portion  42  of hold-switch slider  28 . In one embodiment of the present invention, protuberance  31  may have a thickness between about 0.53 mm and about 0.93 mm, although other thicknesses can be used as well. When the protuberance is actuated, electrical hold-switch  30  can send a signal to a circuit board (not shown) to indicate whether the electronic device should be in one of two states. 
     Although particular embodiments of the present invention have been described above in detail, it will be understood that this description is merely for purposes of illustration. Alternative embodiments of those described hereinabove are also within the scope of the present invention. For example, while the description provided herein describes actuation portion  42  of hold-switch slide  28  as having approximately double the thickness of interface portion  40 , the thickness of the actuation portion can have any value greater than, equal to, or less than the thickness of the interface portion. 
     Furthermore, while actuation portion  42  of hold-switch slide  28  of the above-described embodiments has been described as having two layers of material, the actuation portion can have more than two layers of material. During manufacturing, the additional layers of material can be stamped from a rigid material along with the remaining portions of the hold-switch slide as part of a single unitary piece and folded accordion-style to further increase the thickness of the actuation portion. Cutout  44  then can be stamped through all the layers of material of the actuation portion. Alternatively, cutout  44  could be stamped through all the layers with the first stamping or at some other time, and then the folding can occur. 
     While the description provided herein describes some components of an electronic device, the device may include additional components, e.g., multiple-pin connectors, antennas, speakers, microphones, and/or additional components of the electronic device that have not been shown for simplicity of illustration. 
     Combinations of the above-described embodiments of the present invention or portions thereof may be provided in one electronic device unit. 
     While the description provided herein describes hold-switch  20  to allow a user to indicate one of two states, the hold-switch also can be designed to indicate additional states by providing intermediate positions along the same. For example, the hold-switch apparatus may be adapted to provide tactile feedback to the user when the intermediate positions are reached. 
     In addition, although the description provided herein describes a particular functionality for hold-switch  20 , the present invention can be applied to any actuator that provides an interface for a user to mechanically actuate a component disposed within the device. The actuator may permit the user to control any predetermined function of the device, not just a hold/lock function. Indeed, the functionality controlled by the user may even be a mechanical function rather than an electrical or software-based function as in the embodiments presented above. 
     Furthermore, the description provided herein illustrates electrical hold-switch  30  coupled to a circuit board using a flexible printed circuit, the electrical hold-switch also can couple to the circuit board using any other types of devices that can transmit electrical signals, e.g., a ribbon cable, other types of cable, wires, or a combination thereof. 
     Also, while the description of  FIG. 4  illustrates methods of manufacturing hold-switch slide  28  in accordance with one embodiment of the present invention, other manufacturing techniques also can be used. For example, the hold-switch slide can be milled or cast from a rigid metal, polymeric material, or any other material having sufficiently strong mechanical properties. 
     The above described embodiments of the present invention are presented for purposes of illustration and not of limitation, and the present invention is limited only by the claims which follow.