PATENT DOCUMENT

Publication Number: US-9779889-B2
Application Number: US-201514667117-A
Country: US
Kind Code: B2

Title: Scissor mechanism features for a keyboard

Abstract:
A key supported by a scissor mechanism including interlocking scissor members assembled to mutually pivot along a pivot track. A first scissor member may include a pivot track and an up-stop track and a second scissor member may include at least a first and second extension portion positioned within the pivot track and the up-stop track respectively. When the key is depressed, the first extension portion may slide and at least partially pivot or rotate within the pivot track, and the second extension portion may slide within the up-stop track.

Claims:
We claim: 
     
       1. A key comprising:
 a keycap; 
 a scissor mechanism disposed below the keycap and comprising:
 a first scissor member defining a pivot track and an up-stop track; and 
 a second scissor member comprising a first extension portion positioned within the pivot track and a second extension portion positioned within the up-stop track; and 
 
 an elastomeric dome disposed at least partially below the scissor mechanism; wherein 
 the second extension portion engages the up-stop track to limit an upward stroke of the key. 
 
     
     
       2. The key of  claim 1 , further comprising a retaining feature to pivotally interface with an end portion of the second scissor member. 
     
     
       3. The key of  claim 1 , further comprising a baseplate disposed below the scissor mechanism. 
     
     
       4. The key of  claim 1 , wherein the second scissor member is sized to at least partially fit within an aperture defined by the first scissor member. 
     
     
       5. The key of  claim 1 , wherein the first scissor member is sized to at least partially fit within an aperture defined by the second scissor member. 
     
     
       6. The key of  claim 1 , wherein the first scissor member at least partially overlaps a portion of the second scissor member. 
     
     
       7. A scissor mechanism for a key comprising:
 a first scissor member comprising a pivot track and a stopper track; and 
 a second scissor member comprising a first extension portion positioned within the pivot track and a second extension portion positioned within the stopper track; 
 wherein: 
 upon compression of the scissor mechanism, the first extension portion at least partially pivots and at least partially slides within the pivot track; and 
 the second extension portion at least partially slides within the stopper track and defines a limit to an expansion of the scissor mechanism by engaging a portion of the stopper track. 
 
     
     
       8. The scissor mechanism of  claim 7 , wherein an end portion of the second scissor mechanism is configured to pivotally interface with a retaining feature of a keycap. 
     
     
       9. The scissor mechanism of  claim 7 , wherein the pivot track is at least partially curved. 
     
     
       10. The scissor mechanism of  claim 7 , wherein the pivot track is at least partially angled with respect to a bottom surface of the first scissor member. 
     
     
       11. The scissor mechanism of  claim 7 , wherein the second scissor member is sized to at least partially fit within an aperture within the first scissor member. 
     
     
       12. The scissor mechanism of  claim 7 , wherein the first scissor member is sized to at least partially fit within an aperture within the second scissor member. 
     
     
       13. The scissor mechanism of  claim 7 , wherein the first scissor member at least partially overlaps a portion of the second scissor member. 
     
     
       14. A method of assembling a key comprising:
 positioning a membrane over a base plate comprising a first and second retaining feature; 
 positioning, over the membrane, a scissor mechanism comprising:
 a first scissor member comprising a pivot track and a stopper track; and 
 a second scissor member comprising a first extension portion positioned within the pivot track and a second extension portion positioned within the stopper track, the stopper track configured to define an upper height of the key when the second extension portion engages a portion of the stopper track; 
 
 aligning a first end of the first scissor member with the first retaining feature; and 
 aligning a first end of the second scissor member with the second retaining feature. 
 
     
     
       15. A keyboard comprising:
 a plurality of keys, each key comprising:
 a keycap; 
 a scissor mechanism disposed below the keycap and comprising:
 a first scissor member comprising a pivot track and an up-stop track; and 
 a second scissor member comprising a first extension portion positioned within the pivot track and a second extension portion positioned within the up-stop track; 
 
 an elastomeric dome disposed at least partially below the scissor mechanism; and 
 electronic switch circuitry disposed below the elastomeric dome, wherein: 
 the up-stop track constrains movement of the scissor mechanism due to an engagement of the up-stop track with the second extension portion. 
 
 
     
     
       16. The keyboard of  claim 15 , each keycap of each of the plurality of keys further comprising a retaining feature to pivotally interface with an end portion of the second scissor member. 
     
     
       17. The keyboard of  claim 15 , further comprising a baseplate disposed below the plurality of keys. 
     
     
       18. The keyboard of  claim 17 , the baseplate further comprising a plurality of retaining features, each retaining feature positioned to pivotally interface with an end portion of a respective first scissor member of a respective one key of the plurality of keys. 
     
     
       19. A keyboard comprising:
 a plurality of keys, each key comprising:
 a keycap; 
 a scissor mechanism disposed below the keycap and comprising:
 a first scissor member comprising an up-stop track; and 
 a second scissor member comprising an extension portion positioned within the up-stop track; 
 
 an elastomeric dome disposed at least partially below the scissor mechanism; and 
 electronic switch circuitry disposed below the elastomeric dome; 
 wherein:
 the first scissor member and the second scissor member are coupled to pivot about a fixed point with respect to one another; and 
 the extension portion contacts a portion of the up-stop to limit an upper stroke of the key. 
 
 
 
     
     
       20. The keyboard of  claim 19 , each keycap of each of the plurality of keys further comprising a retaining feature to slidably interface with an end portion of the second scissor member.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a nonprovisional patent application of and claims the benefit to U.S. Provisional Patent Application No. 61/969,405, filed Mar. 24, 2014 and titled “Scissor Mechanism Features for a Keyboard,” the disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments described herein generally relate to structural support systems for depressible keys of a keyboard and, more particularly, to a keyboard having keys supported by an interlocking scissor mechanism. 
     BACKGROUND 
     Many electronic devices receive user input from a keyboard. Traditionally, keyboards include several rows of depressible keys spaced some distance apart. The distance between keys may be selected for aesthetic, functional, structural, dimensional or other reasons. For example, space-constrained electronic devices such as laptop computers may include an integrated keyboard with closely spaced keys. 
     In some examples, close spacing of keys may heighten user awareness of subtle differences between adjacent keys. For example, color, texture, or height differences may become more apparent the closer individual keys are arranged. Such perceivable differences between keys, especially height differences, may negatively affect the typing experience. 
     In many cases, the height of a key may be defined by a multi-part mechanical scissor mechanism also used to translate the key downward a selected distance. Conventional scissor mechanisms may include two scissor members coupled to pivot about a midpoint, with a foot portion of one or both of the scissor members able to slide a certain distance during depression of the key. Once the key is released, the foot portion may slide back, returning the key to the upper height. In this manner, the sliding distance of the foot portion may define the height of the key. Accordingly, to ensure uniform height of closely spaced keys having mechanical scissor mechanisms, each scissor member of each key may require exceptionally low manufacturing tolerance, as slight differences in the dimension of the scissor members may translate to perceivable differences in upper height of adjacent keys. In many cases, low manufacturing tolerances may substantially increase the cost of manufacture by increasing rejection rates, material costs, and manufacture time. 
     Accordingly, there may be a present need for improved mechanical scissor mechanisms for keyboards requiring uniform height of adjacent keys. 
     SUMMARY 
     Embodiments described herein may relate to or take the form of a keyboard including at least a plurality of keys with each key including at least a keycap, a scissor mechanism disposed below the keycap, an elastomeric dome disposed at least partially below the scissor mechanism, and electronic switch circuitry disposed below the elastomeric dome. 
     In these embodiments, the scissor mechanism may include at least a first scissor member defining a pivot track and an up-stop track and a second scissor member including at least a first and second extension portion. The first extension portion may be positioned within the pivot track and a second extension portion may be positioned within the up-stop track. In certain embodiments, each keycap may also include a retaining feature to pivotally interface with an end portion of the second scissor member. 
     Some embodiments may include a configuration in including a baseplate disposed below the plurality of keys that may include retaining features to pivotally interface with an end portion of a respective first scissor member. 
     In certain embodiments, the pivot track of may be at least partially curved or in other examples, the pivot track may be at least partially angled with respect to a bottom surface of the respective first scissor member. 
     In certain embodiments, the second scissor member may be sized to at least partially fit within an aperture within the first scissor member or, in the alternative, the first scissor member may be sized to at least partially fit within an aperture within the second scissor member. In still further embodiments, the first and second members may partially overlap one another. 
     Further embodiments described herein may relate to, include, or take the form of a keyboard including at least a plurality of keys each including a scissor mechanism. the scissor mechanism may include at least a first scissor member including a pivot track and a second scissor member including at least an extension portion. The extension portion may be positioned within the pivot track. In certain embodiments, each keycap may also include a retaining feature to pivotally interface with an end portion of the second scissor member. 
     Some embodiments described herein may relate to or take the form of methods of assembling a key including at least the steps of providing a base plate including at least a first and second retaining feature, positioning a membrane over the base plate, positioning over the membrane a scissor mechanism including at least a first scissor member with a pivot track and an up-stop track, and a second scissor member including at least a first extension portion positioned within the pivot track and a second extension portion positioned within the up-stop track, aligning a first end of the first scissor member with the first retaining feature, and aligning a first end of the second scissor member with the second retaining feature. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Reference will now be made to representative embodiments illustrated in the accompanying figures. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the described embodiments as defined by the appended claims. 
         FIG. 1  depicts a perspective view of a sample electronic device. 
         FIG. 2A  depicts a side cross-section view of an example scissor mechanism including a pivot track and an up-stop track defining an upper height of a key. 
         FIG. 2B  depicts the example scissor mechanism of  FIG. 2A , showing the scissor mechanism partially compressed. 
         FIG. 2C  depicts the example scissor mechanism of  FIG. 2A , showing the scissor mechanism fully compressed. 
         FIG. 2D  depicts a side cross-section view of an alternate example scissor mechanism including an up-stop track defining an upper height of a key. 
         FIG. 3  depicts a top plan view of an example scissor mechanism showing two interlocking scissor members of an example scissor mechanism. 
         FIG. 4  depicts a side cross-section view of the scissor members of  FIG. 3  taken along line  4 - 4  showing an elastomeric dome switch positioned within overlapping apertures of the interlocking scissor mechanism. 
         FIG. 5  depicts a side cross-section view of an example scissor mechanism positioned to interface at least one retaining feature of a base plate disposed below. 
         FIG. 6  is a process flow diagram illustrating example steps of a method of assembling a scissor mechanism for keyboards requiring uniform height of adjacent keys. 
     
    
    
     The use of the same or similar reference numerals in different figures indicates similar, related, or identical items. 
     DETAILED DESCRIPTION 
     Embodiments described herein may relate to or take the form of a key having a scissor mechanism including interlocking scissor members assembled to pivot along a track. It should be appreciated that the various embodiments described herein, as well as functionality, operation, components, and capabilities thereof may be combined with other elements as necessary, and so any physical, functional, or operational discussion of any element or feature is not intended to be limited solely to a particular embodiment to the exclusion of others. 
     For embodiments described herein, a first scissor member may define a pivot track and an up-stop track and a second scissor member may include at least a first and second extension portion positioned within the pivot track and the up-stop track respectively. In this manner, when the key cap is depressed, the first extension portion may slide and at least partially pivot or rotate within the pivot track, and the second extension portion may slide within the up-stop track. 
     Upon release of the key, the first extension portion may slide and at least partially pivot in the opposite direction within the pivot track and the second extension portion may move in the opposite direction within the up-stop track. After a certain travel distance, the second extension portion may reach the end of the up-stop track and may be arrested from traveling further. In this manner, the position of the end of the up-stop track may define the upper height of the key. In other words, the up-stop track may rigidly limit the height of the top of the key when the key is uncompressed or otherwise in the “up” position. 
     In these and related embodiments, the up-stop may independently define the height of the key and the pivot track may define a pivot path for the scissor mechanisms to collapse with respect to one another. 
     Certain embodiments may not necessarily include an up-stop track. For example, the pivot track may by itself be used to exclusively define a pivot path for the scissor members and may be used to define the upper height of the key and/or extension of the scissor members. In other words, the pivot track may rigidly limit the height of the top of the key when the key is uncompressed or otherwise in the “up” position. 
     Likewise, certain embodiments may not include a pivot track. For example, the up-stop track may by itself define and rigidly limit the height of the top of the key when the key is uncompressed or otherwise in the “up” position. In this manner, the up-stop track may be included within a standard fixed pivot point scissor mechanism. 
       FIG. 1  depicts a perspective view of a sample electronic device  100  including a plurality of keys  102 . As depicted, the electronic device  100  is a portable laptop computer including an integrated keyboard  104  including a plurality of rows of keys  102 . Each key  102  may include a key stack defined by at least a key cap, a scissor mechanism, a elastomeric dome, and electronic switch circuitry. Each key  102  may be configured to depress a certain select distance (e.g., 1.0 mm). In many embodiments, the electronic device  100  may be a laptop computer as shown, although it may be appreciated that other electronic devices are contemplated. For example, a key including a scissor mechanism may be included within an electronic device such as a cellular phone, smart phone, tablet computer, desktop computer, peripheral input device (e.g., peripheral keyboard, mouse, or track pad), wearable device, health device, and so on. In other examples, the key may be a discrete electronic part for inclusion within a number of circuits or devices. 
       FIG. 2A  depicts a side cross-section view of an example key  200 . The key  200  may include a key cap  202  having at least one retaining feature  202   a . The key cap  202  may be constructed of any suitable material. For example, in certain embodiments, the key cap  202  may be constructed of metal, plastic, glass, crystal, wood, ceramic, or other materials or combinations of materials. One may appreciate that the material selected for the key cap  202  may be preferably durable, as the key  200  may be depressed thousands of times over the operational live of the key cap  202 . 
     The key cap  202  may be disposed above a scissor mechanism defined by the scissor members  204 ,  206 . The scissor member  204  may be positioned to interface with a bottom surface of the key cap  202 . For example, the scissor member  204  may include a partially angled top surface such that when the key  200  is in an “up” position, the angled portion is parallel to a bottom surface of the key cap  202 . In this manner, the geometry selected for the scissor member  204  may aid in the structural support the key cap  202 . 
     The scissor member  206  may interface with the retaining feature  202   a . In this manner, when the keycap is depressed, the scissor member  206  may pivot at the retaining feature  202   a  to collapse the scissor mechanism of the key  200  downward. 
     The scissor mechanism may be disposed above a baseplate  208  which also may include at least one retaining feature  208   a . The base plate, or feature plate, may be constructed of a number of suitable materials. In certain examples, the base plate may be composed of a single material, or in other examples, the base plate may be composed of a stack of different materials. For example, in certain embodiments, the base plate  208  may be constructed of a metal such as aluminum or steel. In these cases, the retaining feature  208   a  may be made of the same or a different material as the base plate  208 . For example, the base plate  208  may be metal and the retaining feature  208   a  may be plastic. If the retaining feature  208   a  and the base plate  208  are made from different materials, the two may be coupled together using any suitable process. For example, certain embodiments may include a configuration in which the retaining feature  208   a  is adhered to the base plate  208  with an adhesive. In some embodiments, the retaining feature may be mechanically fastened to the base plate with a fastening means such as a screw or clip. In still further embodiments, the retaining feature  208   a  may be welded or otherwise bonded to the base plate  208 . 
     Some embodiments include a configuration in which the base plate  208  includes at least one electrically insulating layer disposed along one or more surfaces of the base plate  208 . In such examples, the base plate  208  may include one or more layers associated with electrical switch circuitry. 
     The base plate  208  and the retaining feature  208   a  may interface with one or both of the scissor members  204 ,  208 . For example, as illustrated, the scissor member  204  may interface with and pivot at the retaining feature  208   a  during depression of the key cap, for example as shown within  FIGS. 2A-2C . In this manner, one may appreciate that because the scissor member  204  pivots at the retaining feature  208   a  and because the scissor member  206  pivots at the retaining feature  202   a , that the scissor mechanism may slide away from the retaining features during depression of the key. 
     As illustrated in  FIG. 2A , the retaining features  202   a  and  208   a  of the key cap  202  and the base plate  208  respectively are depicted as formed along the same side of the scissor mechanism. However, one may appreciate that alternate and additional configurations are contemplated. For example, in certain embodiments, the base plate  208  may include retaining feature  208   a  that is positioned to interface with the scissor member  206 . In these embodiments, the scissor member  206  may pivot with respect to the key cap  202  at the retaining feature  202   a , and may also pivot with respect to the base plate  208  at the retaining feature  208   a.    
     In many embodiments, and as illustrated in  FIG. 2A , the scissor members  204 ,  206  may at least partially interlock. For example, scissor member  204  may define at least a pivot track  204   a  and an up-stop track  204   b . The scissor member  206  may include extension portions  206   a ,  206   b  respectively positioned within the pivot track  204   a  and up-stop track  204   b.    
     The pivot track  204   a  may include a mouth portion and an end portion. The mouth portion may be opened within a bottom surface of the scissor member  204 . The end may be separated from the mouth by n track that may be at least partially curved. In some embodiments, the track may be at least partially angled with respect to a bottom surface of the scissor member  204   a . One may appreciate that the angular or curved relationship between the pivot track  204   a  and the bottom surface of the scissor member  204  may be selected in order to define the path of the scissor mechanism as it is compressed, for example as shown through  FIGS. 2A-2C . 
     In many embodiments, the up-stop track  204   b  may include a mouth portion and end portion. The mouth may be opened within a bottom surface of the scissor member  204 . The end portion may be positioned approximately halfway through the height of the scissor member  204  relative to the bottom surface. In some embodiments, the end portion may be positioned higher or lower relative to the bottom surface. 
     The extension portion  206   b  may be sized to fit within the up-stop track  204   b  such that when the key is in the upper position, the end portion of the up-stop track  204   b  and the extension portion  206   b  may impact one another, completely arresting further extension of the scissor mechanism. In this manner, the up-stop track may stop upward motion of the key cap  202 , rigidly fixing the height of the key  200 . 
     In many embodiments, the scissor mechanisms  204 ,  206  may interlock. For example, the scissor member  204  may include an aperture sized to receive the scissor member  206 . In some embodiments, scissor member  204  may fit within an aperture of the scissor member  206 . In still further embodiments, the scissor members  204 ,  206  may partially overlap one another. 
     One may appreciate that many conventional scissor mechanisms interlock and pivot about a fixed point. Accordingly, scissor members must be constructed of a compliant material such that, during manufacture, one scissor member can be temporarily deformed and inserted within the other scissor member. Complaint materials may also be required in order to install the scissor mechanism within the respective keyboard. One may further appreciate that compliant materials may experience deformation over time, potentially allowing the height of individual keys to undesirably drift over time. 
     However, for many embodiments described herein, the scissor members  204 ,  206  are not required to be made from complaint materials because the interlocking geometry of the scissor members  204 ,  206  allow the use of rigid or otherwise non-compliant materials. Specifically, rigid materials may be used because the mouth portions of the pivot track  204   a  and up-stop track  204   b  eliminate the requirement that one scissor member be deformed to be inserted within the other. 
     For example, the scissor member  204  may be merely placed above the scissor member  206  to align the extension portions  206   a ,  206   b  with the pivot track  204   a  and up-stop track  204   b  respectively. In this manner, the scissor member  204  may slide to interlock with the scissor member  206 . Because the scissor mechanism may be assembled without deforming either scissor member, the scissor members  204 ,  206  may be constructed of a non-compliant material that resists deformation over time and substantially reduces the risk of height drift as experienced by traditionally designed keyboard scissor mechanisms. 
     In these embodiments, the scissor member  204 ,  206  may be constructed of metal or glass-filament doped plastic. The scissor members  204 ,  206  may be formed by injection molding, laser cutting, stamping, or any other suitable process. 
       FIG. 2B  depicts the example scissor mechanism of  FIG. 2A  shown partially compressed in response to a downward force received at the upper surface of the key cap  202 . When the key  200  is depressed, the extension portion  206   a  may slide and at least partially pivot within with pivot track  204   a  as the scissor member  204  pivots at the retaining feature  208   a  and the scissor member  206  pivots at the retaining feature  202   a.    
     As the downward force continues, the scissor mechanism may continue to compress. For example,  FIG. 2C  depicts the scissor mechanism of  FIG. 2A  mechanism fully compressed. As illustrated, the end portion of the pivot track  204   a  interfaces with the extension portion  206   a . Although illustrated showing the scissor member  204  as parallel with the base portion  208 , one may appreciate that the end portion of the pivot track  204   a  may operate as a down-stop if positioned closer to the bottom surface of the scissor member  204 . 
     For example, if the end portion pivot track  204   a  is positioned more proximate to the bottom surface of the scissor member  204 , the travel distance of the key  200  may be fixed. 
       FIG. 2D  depicts a side cross-section view of an alternate example scissor mechanism including an up-stop track defining an upper height of a key. The key  200  may include a key cap  202  having at least one retaining feature  202   a . The key cap  202  may be constructed of any suitable material. For example, in certain embodiments, the key cap  202  may be constructed of metal, plastic, glass, crystal, wood, ceramic, or other materials or combinations of materials. One may appreciate that the material selected for the key cap  202  may be preferably durable, as the key  200  may be depressed thousands of times over the operational live of the key cap  202 . 
     The key cap  202  may be disposed above a scissor mechanism defined by the scissor members  204 ,  206 . The scissor member  204  may include a partially angled top surface such that when the key  200  is in an “up” position, the angled portion is parallel to a bottom surface of the key cap  202 . In this manner, the geometry selected for the scissor member  204  may aid in the structural support the key cap  202 . 
     The scissor member  204  may be positioned to interface with a bottom surface of the key cap  202 , and may be configured to pivot with respect to the scissor member  206  about a fixed pivot point  210 . In this manner, as the key is depressed, the scissor member  204  and scissor member  206  may compress downwardly by pivoting about the pivot point  210 . In many examples, the pivoting motion of the scissor members  204 ,  206  about the pivot point  210  may cause a bottom portion of one or both of the scissor members  204 ,  206  to slide a certain distance along a base plate  208 . 
     Conventional scissor mechanism designs limit the sliding distance of the bottom portions of one or both scissor members to define the upper height of a key cap. For example, setting a slide stop to impact the sliding portion of one or both of the scissor members may prevent the scissor member from further pivoting, and thus may define an upper height of an associated key. Such designs may be exceptionally dependent upon tight manufacturing tolerance of both the dimensions of the individual scissor members, but also of the placement of the slide stop. In many examples, slight manufacturing variations may cause key high to vary substantially. 
     Accordingly, embodiments described herein may include an up-stop track  204   b  within the scissor member  204 . In many embodiments, the up-stop track  204   b  may include a mouth portion and end portion. The mouth may be opened within a bottom surface of the scissor member  204 . The end portion may be positioned approximately halfway through the height of the scissor member  204  relative to the bottom surface. In some embodiments, the end portion may be positioned higher or lower relative to the bottom surface. 
     Corresponding to the up-stop track  204   b  may be an extension portion  206   b  that extends from the scissor member  206 . The extension portion  206   b  may be sized to fit within the up-stop track  204   b  such that when the key is in the upper position, the end portion of the up-stop track  204   b  and the extension portion  206   b  may impact one another, completely arresting further extension of the scissor mechanism. In this manner, the up-stop track may stop upward motion of the key cap  202 , rigidly fixing the height of the key  200  without limiting the sliding distance of the bottom portion of either scissor member. In other words, when the key  200  is depressed and subsequently released, the scissor mechanism may begin to expand to restore the original height of the keycap  202 . As the scissor mechanism expands the individual scissor members  204 ,  206  may pivot about the pivot point  210  in the opposite direction to compression. As the scissor members  204 ,  206  continue to expand, the extension portion  206   b  may engage with, enter or otherwise slide into the mouth portion of the up-stop track  204   b . As the scissor members continue to expand, the extension portion  206   b  may impact the end portion of the up-stop track  204   b , thus arresting further upward motion of the keycap  202 . In this manner, the up-stop track may define the upper height of the key. 
     In many embodiments, the scissor mechanisms  204 ,  206  may interlock. For example, the scissor member  204  may include an aperture sized to receive the scissor member  206 . In some embodiments, scissor member  204  may fit within an aperture of the scissor member  206 . In still further embodiments, the scissor members  204 ,  206  may partially overlap one another. 
       FIG. 3  depicts a top plan view of an example scissor mechanism  300  showing two interlocking scissor members, an external scissor member  304  and an internal scissor member  306 , positioned above a base plate  308 . The base plate may include one or more retaining features  308   a . As illustrated, the external scissor member  304  may receive the internal scissor member  306 , which may include one or more extension portions  306   a ,  306   b  that interlock with the portions of the external scissor member  304 . 
     In these and related embodiments, the internal scissor member  306  may also include a central aperture. In many cases, an elastomeric dome switch may be positioned below or within the aperture of the internal scissor member  305 . 
       FIG. 4  depicts a side cross-section view of the scissor members of  FIG. 3  taken along line  4 - 4  showing a key  400  including an elastomeric dome  410  switch positioned within overlapping apertures of the interlocking scissor mechanism. The elastomeric dome  410  may be a dome that provides tactile feedback when the elastomeric dome  410  is mechanically compressed. In many cases, the elastomeric dome  410  may be make from a complaint and compressible material such as a rubber. In many cases, the elastomeric dome  410  may be positioned above electrical switch circuitry  412  such that when the key cap  402  is compressed downwardly, the elastomeric dome  410  may translate the compression force to a top surface of the electrical switch circuitry in order to complete an electrical circuit. 
     In further embodiments, additional retaining features may be included along the key cap or the base plate in order to prevent the key cap from undesirable or accidental disassembly of the key. For example,  FIG. 5  depicts a side cross-section view of an example scissor mechanism positioned to interface at least one retaining feature  508   b  of a base plate  508  disposed below, and also positioned to interface at least one retaining feature  502   b  along the key cap positioned above. Each of the retaining features  502   b ,  508   b  may be positioned to allow respective portions of the scissor mechanism (e.g., the scissor members  504 ,  506 ) to slide a small distance within the retaining feature during compression of the key  500 . One may appreciate that although two additional retaining features are depicted, that the number, geometry, and positioning of retaining features may vary from embodiment to embodiment. 
       FIG. 6  is a process flow diagram illustrating example steps of a method of assembling a scissor mechanism for keyboards requiring uniform height of adjacent keys. The process may begin at step  600 , in which a feature plate, or base plate, is selected. Thereafter, at step  602 , a membrane including one or more elastomeric domes may be positioned over the base plate. Next, at step  604 , an inner scissor portion (or member) may be aligned with a retaining feature present along the feature plate. Next, at  606 , an outer scissor member may be aligned with an outer scissor a different retaining feature. Lastly, at  608 , a keycap may be positioned over the scissor mechanism. 
     One may appreciate that although many embodiments are disclosed above, that the operations and steps presented with respect to methods and techniques described herein are meant as exemplary and accordingly are not exhaustive. One may further appreciate that alternate step order or, fewer or additional steps may be required or desired for particular embodiments. 
     Although the disclosure above is described in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied, alone or in various combinations, to one or more of the some embodiments of the invention, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments but is instead defined by the claims herein presented.

Metadata:
Filing Date: 20150324
Publication Date: 20171003
Grant Date: 20171003
Priority Date: 20140324
Inventors: YARAK, III WILLIAM P.
ABRAHAM EUAN S.
STEFANSSON ERIK T.
BROCK JOHN M.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H13/70", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2215/006", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/125", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49105", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49105", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2215/006", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/125", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H13/70", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 54142776