PATENT DOCUMENT

Publication Number: US-9761389-B2
Application Number: US-201615264827-A
Country: US
Kind Code: B2

Title: Low-travel key mechanisms with butterfly hinges

Abstract:
A key mechanism can include one or more butterfly hinges. Each butterfly hinge includes a double wing design operative to move between a depressed position and non-depressed position. Hinged coupling mechanisms couple respective arms of the wings together.

Claims:
What is claimed is: 
     
       1. A key mechanism, comprising:
 a keycap; 
 a substrate; and 
 a butterfly hinge movably coupling the keycap to the substrate, the butterfly hinge comprising:
 a first wing; 
 a second wing; and 
 a living hinge flexibly coupling the first wing to the second wing; wherein 
 
 the first wing comprises a first arm extending towards the second wing; 
 the second wing comprises a second arm extending towards the first wing; and 
 the living hinge joins an end of the first arm to an end of the second arm. 
 
     
     
       2. The key mechanism of  claim 1 ,
 the first arm and the second arm each comprise retention features; and 
 the living hinge conforms to the retention features to retain the living hinge to the first arm and the second arm. 
 
     
     
       3. The key mechanism of  claim 2 , wherein:
 the first wing and the second wing comprise a first polymer; and 
 the living hinge comprises a second polymer that is more flexible than the first polymer. 
 
     
     
       4. The key mechanism of  claim 3 , wherein the second polymer is an elastomer. 
     
     
       5. The key mechanism of  claim 3 , wherein the retention features comprise protrusions. 
     
     
       6. The key mechanism of  claim 1 , wherein:
 the living hinge is a first living hinge; 
 the key mechanism further comprises a second living hinge; 
 the first wing comprises a third arm extending towards the second wing; 
 the second wing comprises a fourth arm extending towards the first wing; and 
 the second living hinge joins an end of the third arm to an end of the fourth arm. 
 
     
     
       7. A hinge mechanism for an input key, comprising:
 a first hinge member defining a first arm; 
 a second hinge member defining a second arm and positioned opposite the first hinge member; and 
 a flexible member at least partially encapsulated in the first arm and at least partially encapsulated in the second arm to couple the first arm to the second arm and to substantially synchronize the movement of the first and second hinges. 
 
     
     
       8. The hinge mechanism of  claim 7 , wherein:
 the hinge mechanism is incorporated in a keyboard mechanism comprising:
 a keyboard base; 
 a keycap; and 
 a dome switch coupled to the keyboard base below the keycap; 
 
 the hinge mechanism is coupled to the keyboard base and the keycap and movably supports the keycap relative to the keyboard base; and 
 the flexible member is formed from a metal. 
 
     
     
       9. The hinge mechanism of  claim 8 , wherein:
 the keyboard mechanism comprises a plate coupled to the keyboard base; 
 the first and second hinges each comprise a pivot pin; and 
 the respective pivot pins are captured between the keyboard base and respective portions of the plate. 
 
     
     
       10. The hinge mechanism of  claim 7 , wherein:
 the flexible member defines:
 a first retention feature; and 
 a second retention feature; 
 
 the first arm engages the first retention feature, thereby retaining the first arm to the flexible member; and 
 the second arm engages the second retention feature, thereby retaining the second arm to the flexible member. 
 
     
     
       11. The hinge mechanism of  claim 7 , wherein:
 the first hinge member further comprises:
 a third arm; and 
 a first cross-piece coupled to an end of the first arm and an end of the second arm; and 
 
 the second hinge member further comprises:
 a fourth arm; and 
 a second cross-piece coupled to an end of the second arm and an end of the fourth arm. 
 
 
     
     
       12. The hinge mechanism of  claim 11 , wherein:
 the first arm, the third arm, and the first cross-piece define a first U-shaped portion of a cavity between the first and the second hinge members; and 
 the second arm, the fourth arm, and the second cross-piece define a second U-shaped portion of the cavity between the first and the second hinge members. 
 
     
     
       13. The hinge mechanism of  claim 12 , wherein:
 the hinge mechanism is incorporated in a keyboard comprising a dome switch; and 
 the dome switch is positioned in the cavity between the first and the second hinge members. 
 
     
     
       14. A method of forming a hinge mechanism, comprising:
 forming a first wing comprising:
 a first cross-piece; 
 a first arm extending from a first end of the first cross-piece; and 
 a second arm extending from a second end of the first cross-piece; 
 
 forming a second wing comprising:
 a second cross-piece; 
 a third arm extending from a first end of the second cross-piece; and 
 a fourth arm extending from a second end of the second cross-piece; and 
 
 forming a living hinge coupling an end of the first arm to an end of the third arm. 
 
     
     
       15. The method of  claim 14 , wherein the operation of forming the living hinge comprises:
 positioning the first wing and the second wing in a mold; and 
 injecting a flexible material into the mold and against the end of the first arm and the end of the third arm. 
 
     
     
       16. The method of  claim 15 , wherein:
 the end of the first arm and the end of the second arm each comprise a retention feature; and 
 the operation of injecting the flexible material into the mold comprises at least partially encapsulating the retention features in the flexible material to lock the flexible material to the first arm and the second arm. 
 
     
     
       17. The method of  claim 14 , wherein:
 the living hinge is a first living hinge; and 
 the method further comprises forming a second living hinge coupling an end of the second arm to an end of the fourth arm. 
 
     
     
       18. The method of  claim 14 , wherein the operations of forming the first wing and the second wing comprise injecting a polymer material into a mold. 
     
     
       19. The method of  claim 18 , wherein:
 the method further comprises placing a metal insert into the mold prior to injecting the polymer material into the mold, wherein the metal insert forms at least a portion of the living hinge; and 
 the operation of injecting the polymer material into the mold encapsulates a first portion of the metal insert in the first arm and a second portion of the metal insert in the third arm.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation patent application of U.S. patent application Ser. No. 14/058,448, filed Oct. 21, 2013 and titled “Low-Travel Key Mechanisms Using Butterfly Hinges,” which is a nonprovisional patent application of and claims the benefit of U.S. Provisional Patent Application No. 61/720,373, filed Oct. 30, 2012 and titled “Low-Travel Key Mechanisms Using Butterfly Hinges,” the disclosures of which are hereby incorporated herein by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The disclosed embodiments relate generally to electronic devices, and more particularly to input devices for electronic devices. 
     BACKGROUND 
     Many electronic devices typically include one or more input devices such as keyboards, touchpads, mice, or touchscreens to enable a user to interact with the device. These devices can be integrated into an electronic device or can stand alone as discrete devices that can transmit signals to another device either via wired or wireless connection. For example, a keyboard can be integrated into the housing of a laptop computer or it can exist in its own housing. 
     It is often desirable to reduce the size of electronic devices and minimize machining costs and manufacturing time of such devices. For example, laptops may be designed to be as small and light as possible, but input devices such as a keyboard may occupy relatively large portions of the available interior space. One way to alleviate design constrains of a keyboard is to minimize the z-stackup of key mechanisms. Accordingly, what is needed is an improved key mechanism design. 
     SUMMARY 
     In one aspect, a key mechanism includes a butterfly hinge. The butterfly hinged key mechanism according to various embodiments enable substantially low travel distances with desired tactile response. The key mechanism uses a double wing design operative to move between a depressed position and non-depressed position. In one embodiment, a key mechanism includes a keycap assembly, a support structure, and a butterfly hinge having two independently articulating wings, each wing coupled to the keycap assembly and the support structure, wherein each wing is operative to pivot about its own pivot axis during a keystroke of the key mechanism. 
     In another aspect, a key mechanism includes a keycap assembly, a support structure, and a butterfly hinge that includes two separate wings positioned adjacent to each other such that a cavity is formed between the two wings. Each wing can include a pair of pivot pins and a pair of keycap assembly pins, where the pivot pins are coupled to the support structure and the keycap assembly pins are coupled to the keycap assembly. In addition, a switch, such as a dome switch, can be secured within the cavity between the keycap assembly and the support structure. The switch is operative to bias the keycap assembly in a first position. For example, the switch can bias the keycap assembly upwards when the key mechanism is not subjected to a keystroke event. 
     In another aspect, a key mechanism includes a keycap assembly and a carrier structure that includes a plate and arms fixed to opposite ends of the plate. Each arm can include pivot pin retaining members. A butterfly hinge includes two separate wings positioned adjacent to each other, each wing comprising a pair of pivot pins and a pair of keycap assembly pins. The pivot pins are coupled to the carrier structure and the keycap assembly pins are coupled to the keycap assembly. The carrier structure can house an electronics package that includes circuitry such as a switch, light source, or a display. 
     In another aspect, a butterfly assembly can include first and second wings, each wing comprising a pair of pivot pins and a pair of keycap assembly pins. The pins of each pair are coaxially aligned with their own respective pair axis. First and second hinges couple the first and second wings together. A cavity is formed between the first and second wings when the wings are hinged together. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects and advantages of the invention will become more 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  shows a perspective view of a computing device having a keyboard incorporated therein in accordance with an embodiment; 
         FIG. 2  shows an illustrative perspective view of a section of a keyboard in accordance with an embodiment; 
         FIG. 3  shows a generic and illustrative exploded view of a key mechanism in accordance with an embodiment; 
         FIGS. 4A-4B  show respective illustrative partial cross-sectional views of a key mechanism in a non-depressed position and depressed position in accordance with an embodiment; 
         FIGS. 5A-5C  show illustrative views of butterfly hinge in accordance with an embodiment; 
         FIG. 6  shows illustrative top view of a key mechanism in accordance with an embodiment; 
         FIG. 7  shows an illustrative exploded view of the key mechanism of  FIG. 6  in accordance with an embodiment; 
         FIG. 8  shows an illustrative perspective view of a keycap assembly in accordance with an embodiment; 
         FIG. 9  shows an illustrative perspective view of an electronics package in accordance with an embodiment; 
         FIG. 10  shows an illustrative perspective view of keycap assembly and electronics package in accordance with an embodiment; 
         FIG. 11  shows an illustrative top view of a butterfly hinge in accordance with an embodiment; 
         FIG. 12  shows an illustrative top view of a support structure in accordance with an embodiment; 
         FIG. 13  shows an illustrative top view of a butterfly hinge coupled to support structure in accordance with an embodiment; 
         FIG. 14A  shows an illustrative top view of an alternative support structure in accordance with an embodiment; 
         FIG. 14B  shows an illustrative top view of a yet another alternative support structure in accordance with an embodiment; 
         FIGS. 15-16  show illustrative cross-sectional views of a key mechanism in accordance with an embodiment; 
         FIG. 17  shows an illustrative perspective view of another key mechanism in accordance with an embodiment; 
         FIG. 18  shows an illustrative cross-sectional view of the key mechanism of  FIG. 17  in accordance with an embodiment; 
         FIG. 19  shows an illustrative perspective view of a butterfly hinge and support structure in accordance with an embodiment; 
         FIG. 20  shows an illustrative exploded view of a key mechanism in accordance with an embodiment; 
         FIG. 21  shows an illustrative top view of a butterfly hinge in accordance with an embodiment; 
         FIG. 22  shows an illustrative top view of a butterfly hinge coupled to a carrier structure in accordance with an embodiment; 
         FIG. 23  shows an illustrative bottom view of a butterfly hinge coupled to a carrier structure in accordance with an embodiment; 
         FIG. 24  shows an illustrative perspective view of a key mechanism in accordance with an embodiment; 
         FIG. 25  shows an illustrative cross-sectional view of key mechanism in accordance to an embodiment; 
         FIG. 26  shows an illustrative perspective view of a key mechanism in accordance with an embodiment; 
         FIG. 27  shows an illustrative cross-sectional view of key mechanism in accordance to an embodiment; 
         FIG. 28  shows an illustrative perspective view of carrier structure coupled to a support structure in accordance with an embodiment; 
         FIGS. 29A-29B  show illustrative views of a butterfly hinge in accordance with an embodiment; 
         FIGS. 30A-30C  show illustrative views of a butterfly hinge in accordance with an embodiment; 
         FIGS. 31A-31C  show illustrative views of a butterfly hinge in accordance with an embodiment; 
         FIGS. 32A-32C  show illustrative views of a butterfly hinge in accordance with an embodiment; and 
         FIGS. 33A-33B  show illustrative views of a butterfly hinge in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Some embodiments described herein provide a key mechanism for an input device such as a keyboard that includes a butterfly hinge. The butterfly hinged key mechanism can enable substantially low travel distances with desired tactile response. For example, a butterfly hinged key mechanism can enable keystrokes ranging between 0.1 mm to 2.0 mm, and in some embodiments, the keystroke can be 0.5 mm or 0.75 mm. The key mechanism uses a double wing design operative to move between a depressed position and non-depressed position. Corresponding arms of the butterfly hinge are coupled together with coupling mechanisms. The coupling mechanisms can be, for example, a flexible or living hinge or a gear hinge. The wings of the butterfly hinge articulate independently with each wing operative to pivot about its own pivot axis during a keystroke of the key mechanism. 
       FIG. 1  shows a perspective view of a computing device  10  having a keyboard  12  incorporated therein. Computing device  10  can be any suitable computing device, such as, for example, a laptop computer, a desktop computer, a telephone, smart phone, or gaming device. Keyboard  12  can be integrally formed within computing device  10 . In other embodiments, a keyboard according to an embodiment can be separate from the computing device and can stand alone as a self-contained device. For example, a keyboard may be a communication interface such as, for example, a wired keyboard or a wireless keyboard that can transmit data to and from a computing device. 
       FIG. 2  shows an illustrative perspective view of a section of keyboard  12  (shown as element  12 ) including a key  14 .  FIG. 2  also shows a stackup of web  30  and support structure  70 . Web  30  can be a skeletal structure that surrounds each key of keyboard  10  and provides structural and cosmetic attributes to keyboard  10 . Web  30  can be secured to support structure  70  using any suitable approach such as, for example, by adhesive, glue, weld, pins, interface fits, or any combination thereof. Support structure  70  can provide the platform for components contained within a keyboard. Support structure  70  is sometimes referred to as a feature plate. As defined herein, support structure  70  can include any combination of a feature plate, circuit board, and retaining mechanisms for use in various keyboard mechanism embodiments. 
     Key mechanisms according to various embodiments discussed herein provide a substantially low travel keystroke while maintaining a desired tactile feel over the lifetime of the keyboard. Decreasing the keystroke distance enables keyboard  10  to be built thinner than contemporary keyboards. For example, key mechanisms according to various embodiments described herein can enable keystrokes ranging between 0.1 mm to 2.0 mm, and in some particular embodiments, the keystroke can be 0.5 mm or 0.75 mm. 
     The tactile performance of the key mechanism is consistent regardless of where a user presses down on key  14 . That is, the tactile response of key  14  is substantially the same if the user pressed down at the center (at region  15   a ), the corner (at region  15   b ), or the edge (at region  15   c ) of key  14 . In addition to having a uniform tactile response, the movement of key  14  during a keystroke is also uniform regardless of where it is depressed. For example, imagine a reference plane exists at the top surface of key  14 . When key  14  is pressed at region  15   a , its movement is one in which the top planar surface of key  14  remains parallel to the reference plane throughout the keystroke. The same is true when key  14  is depressed at a corner or edge; the top planar surface remains parallel or substantially parallel to the reference plane throughout the keystroke. Maintaining this parallel movement, with a relatively low travel, and desired tactile response, is accomplished using a butterfly hinge mechanism according to various embodiments. 
     Referring now to  FIG. 3 , a generic and illustrative exploded view of key mechanism  12  is shown. Reference will also be made to  FIGS. 4-5  to assist in the description of how key mechanism  12  operates. Key mechanism  12  can include keycap  14 , substructure  20 , web  30 , switch  40 , butterfly hinge  50 , and support structure  70 . Assembly of key mechanism is as follows. Keycap  14  is secured to substructure  20  to form a keycap assembly. The keycap assembly can fit within the inner perimeter of web  30 , and web  30  is secured to an outer boundary of support structure  70 . In other embodiments, the keycap assembly can exist above web  30 . Butterfly hinge  50  is secured to substructure  20  and support structure  70 , and is also contained within the inner perimeter of web  30 . Switch  40  resides within cavity  53  of butterfly hinge  50  and can be secured to either the keycap assembly or support structure  70 . 
     Keycap  14  is the portion of key mechanism that a user depresses during a keystroke. Keycap  14  can take any suitable shape and can be constructed from any suitable material. For example, keycap  14  can be constructed from plastic, glass, or metal. In some embodiments, keycap  14  can be constructed from a translucent material so that a backlight can shine through. Moreover, a translucent keycap can be masked so that it displays a character. 
     Substructure  20  can take any suitable shape and be constructed from any suitable material. Substructure  20  can fulfill several different functions in its use in key mechanism. In one function, it provides pin retaining mechanisms  22  for coupling to butterfly hinge  50 . In particular, substructure can include four pin retaining mechanisms  22 , each one operative to couple to one of keycap assembly pins  54  and  57  of butterfly hinge  50 . Additional details of pin retaining mechanisms  22  are discussed in more detail below. 
     As another function, substructure  20  can serve as a light guide panel (hereinafter “LGP”) for distributing backlight emitted from a light source such as, for example, a LED. In embodiments that use substructure  20  as a LGP, the shape of substructure  20  can be designed to minimize the impact of backlighting performance. For example, substructure  20  can occupy an outer periphery of keycap  14 , thereby leaving an interior portion of keycap largely unobfuscated. The use of a LGP as part of substructure  20  is discussed in more detail below. 
     The combination of keycap  14  and substructure  20  (and potentially other components such as switch  40 , electronics (not shown), and flex circuitry (not shown)) is sometimes referred to herein as a keycap assembly. In some embodiments, depending on the stiffness of keycap  14 , a relatively strong substructure is needed to provide the rigidity needed for property operation of key mechanism  12 . For example, if keycap  14  is constructed from a plastic, substructure  20  may be constructed from metal. In other embodiments, keycap  14  can be constructed from a relatively stiff material such as glass and substructure can be constructed from a plastic or metal material. In yet another embodiment, keycap  14  and substructure  20  can be an integrally formed keycap assembly. For example, keycap  14  and substructure  20  can be formed from a single plastic mold or a single piece of machined glass. 
     Switch  40  can be any suitable mechanical switch such as a dome switch. A metal dome switch or an elastomeric dome switch may be used, for example. As will be explained more detail in connection with  FIG. 4 , switch  40  can bias the keycap assembly to be in its natural, non-depressed position. In other words, when key mechanism is not undergoing a keystroke event, switch  40  can bias the keycap assembly to be in its non-depressed position. When key mechanism  12  is subjected to a keystroke event, switch  40  can buckle under the force applied to keycap  14 , thereby enabling the keycap assembly to be in its depressed position. When the keycap assembly is in its depressed position, the keystroke can be registered by circuitry associated with switch  40  or by other circuitry contained within key mechanism (e.g., a parallel plate sensor membrane). 
     Butterfly hinge  50  functions as the movable hinge that enables the keycap assembly to move relative to support structure  70 . Butterfly hinge  50  can include wings  51  and  52 , which are separate components coupled together by coupling mechanisms  60 . Wing  51  includes keycap assembly pins  54  and pivot pins  55 , and wing  52  includes keycap assembly pins  57  and pivot pins  56 . Wings  51  and  52  may each include a cutout such that when wings  51  and  52  are coupled together, cavity  53  exists. Cavity  53  can have any suitable shape such as, for example, a square, a rectangle, circle, or ellipse. 
     Keycap assembly pins  54  and  57  are coupled to pin retaining mechanisms  22   a ,  22   b  of substructure  20 . Pivot pins  55  and  56  are coupled to pivot pin retaining members  75  and  76 , respectively, of support structure  70 . The manner in which pins are coupled to substructure  20  and support structure  70  vary depending on specific embodiments, discussed below. 
     Coupling mechanisms  60 , though coupling wings  51  and  52  together, may enable wings  51  and  52  to move independent of each other. Thus, if one wing were locked in a position, the other wing would be free to move, and vice versa. However, as will be explained in  FIGS. 4-5 , wings  51  and  52  are both secured to support structure  70  and are operative to move (or flap) in concert with each other, with coupling mechanism  60  changing between substantially flat-shaped and v-shaped positions. Many different embodiments of coupling mechanisms  60  can be used with butterfly hinge  50 . These embodiments are discussed in more detail in connection with the description below accompanying  FIGS. 4-5 . In other embodiments, coupling hinges  60  can be omitted from butterfly hinge  50 . 
     Support structure  70  can be constructed from any suitable material or combination of different materials. The specific construction and materials used depends on particular key mechanism embodiment being employed, and thus these notable features are discussed in more detail below. One notable feature of structure  70  shown in  FIG. 3  is cutouts  77 . Cutouts  77  are positioned in predetermined positions on structure  70  so that pin retaining mechanism  22  of substructure  20  can fit into a respective cutout when the key mechanism is in its depressed position. This nestling of components within each other during a keystroke helps key mechanism  12  maintain its relatively thin z-height. 
     Referring now to  FIGS. 4A-4B , illustrative partial cross-sectional views of key mechanism  12  are shown in a non-depressed position ( FIG. 4A ) and depressed position ( FIG. 4B ). Both figures show keycap  14 , pin retaining mechanism  22   a ,  22   b  of substructure  20 , wing  51  with pivot pin  55  and keycap assembly pin  54 , wing  52  with pivot pin  56  and keycap assembly pin  57 , coupling member  60 , switch  40 , support structure  70 , and pivot pin retaining members  75  and  76 . Other components of key mechanism  12  have been omitted to provide less cluttered figures and to promote ease of discussion. 
       FIGS. 4A-4B  also show keycap plane  400 , pivot pin plane  410 , and structure plane  420 . Regardless of whether key mechanism  12  is in its depressed or non-depressed state, the position of pivot pin plane  410  and structure plane  420  remain fixed, as indicated by the set of double arrows demarcating the z-height (shown as Zfixed) between the two planes in both figures. The z-height between keycap plane  400  and the structure plane  420 , however, changes depending on the position of key mechansim  12 . In the depressed position, the z-height is Zdepressed, as shown, and in the non-depressed position, the z-height is Znon-depressed. 
     Pivot pin retaining members  75  and  76  are operative to securely hold pivot pins  55  and  56  in place, while enabling pivot pins  55  and  56  to rotate within pivot pin retaining members  75  and  76 . Keycap assembly pin  57  is coupled to pin retaining mechanism  22   a , which can secure keycap assembly pin  57  to substructure  20  (not shown) in a manner similar to how pivot pin retaining members  75  and  76  secure their pins. Thus, pin retaining mechanism  22   a  may rotate when keycap  14  is undergoing a keystroke. Keycap assembly pin  54  can be coupled to pin retaining mechanism  22   b , which is operative to enable keycap assembly pin  54  to slide horizontally within the pin retaining mechanism as key mechanism  12  travels up and down. Thus, the pin retaining system uses three sets of pin retaining mechanisms (one set for each pair of pins  57 ,  56 , and  55 ) for securing rotating pins  57 ,  56 , and  55  in place with minimal horizontal movement, and a fourth set (for pins  54 ) for securing sliding pins  54  in place with a fixed amount of horizontal movement. Additional aspects and features on the retaining mechanisms are discussed in more detail below for various different embodiments. 
     Referring collectively now to  FIGS. 4A-4B  and  FIGS. 5A-5C , wings  51  and wings  52  pivot about their own respective pivot axes. Wing  51  pivots about axis  510 , which runs co-axially with the center axis of pivot pins  55 , and wing  52  pivots about axis  520 , which runs co-axially with the center axis of pivot pins  56 . Since pivot pins  55  and  56  are secured in position with respect to structure  70  (as shown by fixed z-height Zfixed), it is the outer portions of wings  51  and  52  (particularly at keycap assembly pins  54  and  57 ) that move relative to pivot pins  55  and  56 . 
     In the non-depressed position, switch  40  is in its natural unbuckled position. In this position, switch  40  biases keycap  14  upwards when key mechanism  12  is not being subjected to a keystroke event. With the upward bias of switch  40 , it pushes keycap  14  up, resulting in having pin retaining mechanism  22   a ,  22   b  pull keycap assembly pins  54 ,  57  of wings  51 ,  52  up. Since, pivot pins  55  and  56  are secured in place, wings  51  and  52  pivot about their own respective pivot axes  510  and  520 , and keycap assembly pin  57  remains fixed in position, keycap assembly pin  54  slides horizontally to the left (shown here as the −X direction) within pin retaining mechanism  22   b . As shown, in the non-depressed position, wings  51  and  52  resemble a v-shaped hinge, with its outer portions (e.g., pin regions  57  and  54 ) raised relative to pin plane  410 . 
     In the depressed position, switch  40  is buckled, and keycap  14  has moved down vertically, thereby pushing the outer portions of wings  51  and  52  down towards support structure  70 . Pins  57 ,  56 , and  55  are secured in place and rotate within their secured positions, whereas keycap assembly pin  54  slides horizontally within its retaining mechanism in the +X direction. As shown in  FIGS. 4A-4B , the relative position of keycap assembly pin  54  moves to the +X direction when the key mechanism  12  is in the depressed position. Moreover, in the depressed position, wings  51  and  52  resemble a log shaped hinge, with all pins  54 - 57  in substantially the same plane. 
     Use of the butterfly hinge  50  in key mechanism  12  provides not only a low travel keystroke, but a stable key mechanism. The double wing design of butterfly hinge  50  distributes loading evenly with respect to the keycap assembly. The evenly distributed loading is accomplished by placing the load bearing keycap assembly pins  57  and  54  at the outer portions of wings  51  and  52 , respectively. This stable loading is translated to keycap  14  because regardless of where a user presses down on keycap  14 , the load will be distributed across the key, resulting in a tactically desirable and non-wavering keystroke. 
     Referring now to  FIGS. 6-16 , a low travel key mechanism according to an embodiment is discussed. Features discussed above in connection with  FIGS. 2-5  apply to similar features discussed in connection with  FIGS. 6-16 , however, notable features will be discussed in more detail.  FIG. 6  shows an illustrative top view of key mechanism  612 , showing keycap  614  and a few internal features shown by hidden lines. In particular, substructure  620  (with integrated light guide panel) and LED  648  are shown by hidden lines. 
       FIG. 7  shows an illustrative exploded view of key mechanism  612 . As shown, key mechanism  612  can include keycap  614 , substructure  620 , web  630 , electronic package  642 , butterfly hinge  650 , support structure  670 , and cover plate  680 . Cover plate  680  can be a printed circuit board or a heat spreader.  FIG. 8  shows an illustrative perspective view of the bottom of keycap  614  and substructure  620 , with substructure  620  secured to keycap  614 . In this embodiment, substructure  620  doubles as a pin retaining structure and a LGP. The LGP aspect of substructure  620  is evident in that it occupies a majority of the surface area of keycap  614  and includes notch  624  for enabling a light source, such as LED  648 , to fit adjacent to the LGP. 
     As shown, substructure  620  has pin retaining mechanisms  622   a  and  622   b  located near the corners of keycap  614 . Pin retaining mechanisms  622   a  are operative to securely couple pins and allow the pins to rotate freely within. In particular, pin retaining mechanisms  622   a  can be c-clip retaining members. Pin retaining mechanisms  622   b  are operative to slidably couple pins therein. That is, the pins are retained within the mechanism, but are allowed to slide horizontally within the mechanism when the key mechanism is undergoing a keystroke event. Pin retaining mechanism  622   b  can have an extruded L-shape that extends a minimum distance sufficient to contain the sliding pin. Note that both pin retaining mechanisms  622   b  may face each other. It is understood that any suitable number of different configurations of pin retaining mechanisms  622   b  can be used to achieve the desired coupling effect. 
       FIG. 9  shows an illustrative perspective bottom view of electronics package  642 . Electronics package can include switch  640 , which is mounted to flexible printed circuit board (PCB)  643 , connector portion  644 , support portion  645 , and LED  648 . In other embodiments, electronics package  642  can include a display such as OLED display. Referring to both  FIGS. 9 and 10 , electronics package  642  is mounted to substructure  620 . In this arrangement, the base of switch  640  is pressed against substructure  620 , and LED  648  fits within notch  624  ( FIG. 8 ). Support portion  645  floats relative to PCB  643  via connector portion  644  and surrounds keycap  614  and substructure  620 . Thus, when key mechanism  612  is assembled, the nipple side of switch  640  faces downward towards support structure  670  (not shown), and passes through cavity  653  of butterfly hinge  650  (shown in  FIG. 11 ). In addition, when assembled, support portion  645  can align with web  630  ( FIG. 7 ) and both web  630  and support portion  645  can be secured to support structure  670  ( FIG. 7 ). 
       FIG. 11  shows an illustrative top view of butterfly hinge  650 . Butterfly hinge  650  includes wings  651  and  652 . No coupling mechanisms are shown coupling wings  651  and  652  together in this detailed view. Wing  651  can include pivot pins  656 , keycap assembly pins  657 , and upstop members  658 . Wing  652  can include pivot pins  655 , keycap assembly pins  654 , and upstop members  659 . Both wings  651  and  652  are shaped so that cavity  653  exists when the wings are placed adjacent to one another. Pivot pins  655  and  656  and upstop members  658  and  659  extend away from the outside surface of butterfly hinge  650 , whereas keycap assembly pins  654  and  657  extend within butterfly hinge  650 . Pivot pins  655  and upstop members  659  may be coplanar with each other and extend about the same distance away from butterfly hinge  650 . Similarly, pivot pins  656  and upstop members  658  may be coplanar with each other and extend about the same distance away from butterfly hinge  650 . 
       FIG. 12  shows an illustrative top view of support structure  670 . Support structure  670  has pivot pin retaining members  675  and  676 , and upstops  678  and  679 . Pivot pin retaining members  675  and  676  are operative to secure pivot pins  655  and  656 , respectively, in place but enable the pins to rotate freely within. Pivot pin retaining members  675  and  676  may be c-clip types of retaining members. Upstops  678  and  679  may be hook shaped members operative to engage upstop members  658  and  659 , respectively. Upstops  678  and  679  ensure that wings  651  and  652  do not travel up beyond a pre-determined vertical distance when key mechanism is in its natural, un-depressed position. Support structure  670  can also include cutouts  677 . 
       FIG. 13  shows an illustrative top view of butterfly hinge  650  coupled to support structure  670 . In this view, pivot pins  655  and  656  are secured to support structure  670  via pivot pin retaining members  675  and  676 , respectively, and upstop members  658  and  659  are positioned under upstops  678  and  679 , respectively.  FIG. 13  also shows how end portions (centered around keycap assembly pins  654  and  657 ) are positioned over cutouts  677 .  FIG. 15  shows an illustrative cross-sectional view of key mechanism  612 , showing the interaction of pivot pins  655  and  656  with pivot pin retaining members  675  and  676  and, upstop members  658  and  659  with upstops  678  and  679 . 
       FIGS. 14A-14B  show perspective views of alternative support structures according to various embodiments. In particular,  FIG. 14A  shows a different retaining member configuration for securing butterfly hinge  650  to support structure  1400 . Support structure  1400  includes c-clip retaining members  1422 , and hook retaining members  1432  for retaining pins of a butterfly hinge (not shown). Structure  1400  also includes upstop members  1440 . 
       FIG. 14B  shows support structure  1450  that includes pivot pin retaining member  1462  and upstop members  1470 . Pivot pin retaining member  1462  is a one piece construction including two circular eyes for holding pivot pins. Pivot pin retaining member  1462  can have a spring loaded bias to press against the butterfly hinge when its pivot pins are secured within the eyes. 
       FIG. 16  shows another illustrative cross-sectional view of key mechanism  612  in a non-depressed position. This view shows switch  640  in a non-buckled position, wings  651  and  652  in a v-shaped arrangement, pin retaining mechanisms  622   a ,  622   b , keycap assembly pins  657  and  654 , and other components. 
       FIGS. 17-19  show various illustrative views of another key mechanism according to an embodiment. In particular,  FIG. 17  shows an illustrative perspective view of key mechanism  1712  in a non-depressed position.  FIG. 18  shows a cross-sectional view taken along line  18 - 18  in  FIG. 17 . And  FIG. 19  shows an illustrative perspective view of key mechanism without a keycap assembly. Key mechanism  1712  exhibits many of the same attributes of the generic key mechanism of  FIGS. 2-5 , but includes more details regarding its hinge and support structure. As shown in  FIG. 17 , key mechanism  1712  can include keycap  1714 , laminate layer  1716 , substructure  1720 , switch  1740 , butterfly hinge  1750 , and support structure  1770 . 
     Butterfly hinge  1750  can include wings  1751  and  1752 . Wing  1751  can include pivot pins  1755  and keycap assembly pins  1754 . Wing  1752  can include pivot pins  1756  and keycap assembly pins  1757 . Keycap assembly pins  1754  and  1757  are coupled to substructure  1720 , and pivot pins  1755  and  1756  are coupled to support structure  1770 . Pivot pins  1755  and  1756  are secured within slots  1775  and  1776  of support structure  1770 . Slots  1775  and  1776  may be cavities in the structure  1770  that are covered by laminate material  1716 . In some embodiments, laminate material  1716  can be the same as a web (such as web  30 ). In effect, laminate material  1716  locks pivot pins  1755  and  1756  in place within support structure  1770 . In this embodiment, pivot pins  1755 ,  1756  and keycap assembly pins  1754 ,  1757  all extend away from butterfly hinge  1750 . 
     Switch  1740  can fit in a cavity existing between wings  1751  and  1752 , as shown. In this particular embodiment, the base of switch  1740  can reside on support structure  1770 , as opposed to being fixed to substructure  1720 . When key mechanism  1712  is in its non-depressed position, switch  1740  is in its unbuckled state and props or biases the keycap assembly up. When key mechanism  1712  is in its depressed position, switch  1740  will be buckled and wings  1751  and  1752  will be pressed down in a log shaped position, with all pins  1754 ,  1755 ,  1756 ,  1757  in substantially the same plane. 
     Each wing can include upstops  1910 , which are operative to limit the up-travel of the wings when the key mechanism is in its undepressed position. Upstops  1910  may engage laminate layer  1716  in the undepressed position. Upstops  1910  may be shaped at an angle to enable flush interfacing with the laminate layer. 
       FIGS. 20-28  show various illustrations of a key mechanism  2012  using a carrier plate according to an embodiment. References to key mechanism  2012  include all  FIGS. 20-28 , with occasional specific reference to individual figures. The carrier plate, as opposed to the structural support is responsible for securing the pivot pins of the butterfly hinge in place. In addition, the carrier plate can also support an electronic package. Referring now to  FIG. 20 , there is shown an exploded view of key mechanism  2012 . Key mechanism  2012  can include keycap  2014 , substructure  2020 , carrier plate  2090 , electronics package  2042 , switch  2040 , butterfly hinge  2050 , web  2030 , and circuit board  2080 . Components discussed earlier in connection with  FIGS. 2-5  may share characteristics with similar components of key mechanism  2012 . For example, keycap  2014  and substructure  2020  and its interaction with keycap assembly pins of butterfly hinge  2050  is similar to how keycap  14  and substructure  20  interact with butterfly hinge  50 . 
     Carrier plate  2090  is constructed to fit within cavity  2053  ( FIG. 21 ) of butterfly hinge  2050  and be secured to circuit board  2080 . Carrier plate  2090  can be secured to circuit board  2080  in any number of suitable different ways. For example, it can be glued or welded to circuit board  2080 . As another example, carrier plate  2090  can have several posts that extend from a bottom surface of the carrier plate and engage with corresponding cavities in circuit board  2080 . As yet another example, carrier plate  2090  can be secured in place with two or more clips  2802 , as shown in  FIG. 28 . When carrier plate  2090  is secured to circuit board  2080 , it secures pivot pins  2056  and  2055  in place so that they are free to rotate in place within pivot pin retaining members  2095  and  2096 . The pin arrangement of butterfly hinge  2050  is shown in more detail in  FIG. 21 , and the pivot pin retaining members of carrier plate  2090  is shown in more detail in  FIGS. 22, 23, 24, and 25 . 
     Butterfly hinge  2050  can include two wings  2051 ,  2052  connected together using a coupling mechanism (not shown). Any suitable coupling mechanism can be used. Various examples of such coupling mechanism are described in more detail below. Cavity  2053  can exist between the two wings  2051 ,  2052  when placed adjacent to each other. 
     Carrier plate  2090  can be constructed from any suitable material such as metal or plastic. The construction of carrier plate  2090  can include a flat plate  2091 , which is flanked by two raised arm members  2092 . Each raised arm member  2092  can include pivot pin retaining member  2095  and pivot pin retaining member  2096 . In addition, each raised arm member  2092  can include two upstop protrusions  2099 . Upstop protrusions  2099  are operative to engage upstops  2059  of butterfly hinge  2050  when key mechanism  2012  is in its non-depressed position. Protrusions  2099  prevent wings  2051 ,  2052  of butterfly hinge  2050  from traveling beyond a fixed vertical up direction. 
     Flat plate  2091  can serve as a platform for electronics package  2042 , which can include among other features, switch  2040 , LED, light guide panel, display, and/or flex circuitry. This arrangement promotes easy connections between circuit board  2080  and electronics package  2042  because carrier plate  2090  is directly connected to circuit board  2080 . This is in contrast to the flex printed circuit board embodiment associated with key mechanism  612  (described earlier). Moreover, as shown in this embodiment, switch  2040  is mounted such that its dome is facing substructure  2020  and keycap  2014 . Thus, when switch  2040  is in its unbuckled position, it is operative to bias keycap  2014  and substructure  2020  upwards. 
     Referring now to  FIGS. 26 and 27 , there are shown pin retaining mechanisms  2022   a ,  2022   b  of substructure  2020  interfacing with keycap assembly pins  2054  and  2057 . In particular,  FIG. 27  shows the different pin retaining mechanisms, pin retaining mechanism  2022   a  for securing keycap assembly pin  2054  in place so that it rotates in place, and pin retaining mechanism  2022   b  for enabling keycap assembly pin  2057  to slide horizontally when key mechanism  2012  is being depressed. 
       FIGS. 29-33  show several different butterfly hinge embodiments that can be used in conjunction with a key mechanism. Each of the embodiments discussed in connection with  FIGS. 29-33  include two wings that are coupled together with a coupling mechanism. The nature of the coupling mechanism varies and can include two general types: living hinge and gear hinge. A living hinge coupling mechanism can be a flexible material or combination of materials that physically attaches the two wings together. A gear hinge is a coupling mechanism built into the wings themselves that allows for a gear-like interaction between the wings. 
       FIGS. 29A-29B  show illustrative top and partial perspective views of butterfly hinge  2900  in accordance with an embodiment. Hinge  2900  includes wings  2910  and  2920  coupled together with living hinge  2930 . Wings  2910  and  2920  can include pins as shown and can be made, for example, from a glass-filled plastic. Living hinge  2930  can be made from a plastic material that is softer than the material used to make the wings. Wings  2910  and  2920  also include self-locking structures  2912  and  2922 . 
     Butterfly hinge  2900  can be manufactured using a double-shot process, wherein the first shot creates wings  2910  and  2920 , and the second shot forms living hinge  2930 . When the second shot is applied, it self-locks itself to self-locking structures  2912  and  2922  to couple wings  2910  and  2920  together. Note that the thickness of living hinge  2930  is substantially thinner at center axis  2940  of butterfly hinge  2900  than at other portions of living hinge  2930 . The thinner section at the junction between wings  2910  and  2920  can promote ease of flexing between wings  2910  and  2920 . 
       FIGS. 30A-30B  show illustrative top and perspective views of butterfly hinge  3000  in accordance with an embodiment. Butterfly hinge  3000  can be manufactured by insert molding wings  3010  and  3020  around living hinge  3030 . Molded wings  3010  and  3020  can include the pins, as shown. Living hinges  3030  can be part of a metal strip  3050  containing several living hinges  3030  (as shown in  FIG. 30C ). Including several living hinges  3030  on a single strip can increase manufacturing throughput of butterfly hinge  3000 . After wings  3010  and  3020  are molded on to strip  3050 , the strip can be cut away to yield an individual butterfly hinge  3000  that is suitable for use in a key mechanism. Wings  3010  and  3020  can be constructed, for example, with a plastic such as a glass filled plastic. 
     Living hinge  3030  can be a relatively thin piece of metal (e.g., steel) that is operative to bend to enable wings  3010  and  3020  to move when used in a key mechanism. Living hinge  3030  can include retention features  3012  and  3014  to promote adhesion to the wings when the wings are molded thereto. When wings  3010  and  3020  are molded onto strip  3050 , shutoffs can be used to prevent wings from completely covering living hinge  3030 , thereby leaving a portion of living hinge  3030  exposed. 
       FIGS. 31A-31C  show various views of butterfly hinge  3100  in accordance with an embodiment. Butterfly hinge  3100  can be constructed by coupling metal wings  3110  and  3120  together with an injection molded living hinge  3130 . Wings  3110  and  3120  can be constructed from a die cast or forged metal. In one embodiment, wings can be formed from a zinc die cast. In this embodiment, the pins are also formed in the die cast or forged metal. Wings  3110  and  3120  can be constructed to have retention features  3112  and  3122  to assist living hinge  3130  retention. Living hinge  3130  can be any suitable compliant material capable of bending. For example, living hinge  3130  can be constructed from a plastic or rubber material. 
       FIGS. 32A-32C  show illustrative views of butterfly hinge  3200  in accordance with an embodiment. Butterfly hinge  3200  can be constructed from two metal cores  3201  and  3202  (shown by hidden lines) that are overmolded with a molding material. The molding material fully encapsulates metal cores  3201  and  3202  to form wings  3210  and  3220 , which each include pins formed by the overmold, and living hinge  3230 . Cores  3201  and  3202  can be separate metal components with retention features  3205  incorporated therein. Retention features  3205  can enable the injected molded material to self-lock itself to cores  3201  and  3202 . 
     Living hinge  3230  can be formed from the overmold that couples cores  3201  and  3202  together. It can be sized to be relatively narrow at the junction between wings  3210  and  3220  to promote ease of movement. Hinge  3200  can be constructed in batch fashion in that strip  3250  can contain several cores. The cores can be overmolded and then die cut to yield each butterfly hinge  3200 . 
     In another embodiment (not shown), a butterfly hinge can be constructed from two metal cores, having forged or die cast pins, that are at least partially overmolded with a molding material, but in a way so that the pins are left exposed. This way, the metal pins are exposed and formed from metal, as opposed to an injection molded plastic. A living hinge is formed from the injection molded plastic coupling the two cores together. 
       FIGS. 33A-33B  show illustrative views of butterfly hinge  3300  in accordance with an embodiment. Hinge  3300  includes wings  3310  and  3320  that each include pins and upstops, as shown. Wing  3310  has gear members  3315  and wing  3320  has gear members  3325 . Gear members  3315 ,  3325  interface with each other to form a gear hinge. 
     Referring to  FIG. 33B , a close up of the gear hinge is shown. In particular the teeth of the gear members are shown. Wing  3310  has upper tooth  3315 U and lower tooth  3315 L, and wing  3320  has lower tooth  3325 L and upper tooth  3325 U. Upper tooth  3315 U interfaces with lower tooth  3325 L and upper tooth  3325 U interfaces with lower tooth  3315 L. This upper/lower tooth configuration can promote coupling of wings  3310  and  3320  when used in a key mechanism. 
     Various embodiments have been described in detail with particular reference to certain features thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the disclosure. And even though specific embodiments have been described herein, it should be noted that the application is not limited to these embodiments. In particular, any features described with respect to one embodiment may also be used in other embodiments, where compatible. Likewise, the features of the different embodiments may be exchanged, where compatible.

Metadata:
Filing Date: 20160914
Publication Date: 20170912
Grant Date: 20170912
Priority Date: 20121030
Inventors: LEONG CRAIG C.
NIU JAMES J.
BROCK JOHN M.
HENDREN KEITH J.
WILSON, JR. THOMAS W.
BERG BRUCE E.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H3/122", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2227/036", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/70", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2227/028", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/705", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0238", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2237/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2227/036", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2227/028", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/122", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0238", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2237/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/705", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/705", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/70", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2237/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2227/036", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2227/028", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/122", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0238", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 50545986