PATENT DOCUMENT

Publication Number: US-9064642-B2
Application Number: US-201313792128-A
Country: US
Kind Code: B2

Title: Rattle-free keyswitch mechanism

Abstract:
A keyswitch mechanism having reduced key rattle and a keyboard having reduced key rattle. A rattle suppression mechanism may be formed on a portion of the scissor mechanism or on a portion of the keycap. The rattle suppression mechanism is configured to maintain force on the portion of the scissor mechanism abutting the keycap.

Claims:
We claim: 
     
       1. A keyswitch mechanism having reduced key rattle, comprising:
 a base having a surface; 
 a scissor mechanism slidably coupled to the base, the scissor mechanism including a keycap bar, the keycap bar comprising:
 a first scissor slide pin at a first end of the keycap bar; 
 a second scissor slide pin at a second end of the keycap bar; and 
 a keycap contacting portion extending between the first and second scissor slide pins and distinct from the first and second scissor slide pins; 
 
 a keycap abutting at least the keycap contacting portion of the keycap bar; and 
 a rattle suppression mechanism included on the keycap contacting portion of the keycap bar, the rattle suppression mechanism configured to maintain a biasing force between the keycap bar and the keycap. 
 
     
     
       2. The keyswitch mechanism of  claim 1 , wherein:
 the scissor mechanism includes:
 a first scissor arm frame including a base portion coupled to the base and the keycap bar; 
 a second scissor arm; and 
 pivots to rotatably attach the second scissor arm to the first scissor arm frame; 
 
 the keycap includes a first slide groove, a second slide groove, and a scissor contact surface extending between the first and second slide grooves, the first and second slide grooves being sized and located to slidably hold the first and second scissor slide pins of the scissor mechanism, respectively; and 
 the rattle suppression mechanism includes at least one rattle suppression feature formed on the keycap portion of the first scissor arm frame. 
 
     
     
       3. The keyswitch mechanism of  claim 2 , wherein:
 the first scissor arm frame of the scissor mechanism includes:
 a base bar forming the base portion, the base bar having a first base bar end, a second base bar end and a base bar axis extending between the first base bar end and the second base bar end, the first scissor arm frame aligned such that the base bar axis is substantially parallel to the surface of the base;and 
 two side bars having side bar axes substantially perpendicular to the base bar axis, one side bar extending from the first base bar end and the other side bar extending from the second base bar end; and 
 
 the first and second slide grooves of the keycap are further sized and located to slidably hold the first and second scissor slide pins of the scissor mechanism, respectively, such that the at least one rattle suppression feature formed on the keycap bar of the scissor mechanism is further configured to press against the scissor contact surface of the keycap, thereby tightening a fit of the first and second scissor slide pins within the first and second slide grooves. 
 
     
     
       4. The keyswitch mechanism of  claim 3 , wherein at least a portion of the keycap bar of the scissor mechanism is elastically deformable. 
     
     
       5. The keyswitch mechanism of  claim 4 , wherein the deformable portion of the keycap bar of the scissor mechanism is at least one of:
 flexible; or 
 compressible. 
 
     
     
       6. The keyswitch mechanism of  claim 3 , wherein the at least one rattle suppression feature of the keycap bar of the scissor mechanism includes at least one of:
 an arch in the keycap bar; 
 a bump on the keycap bar; or 
 at least one ridge on the keycap bar. 
 
     
     
       7. The keyswitch mechanism of  claim 2 , wherein at least one of:
 a first contact surface of the first slide groove of the keycap and a second contact surface of the second slide groove of the keycap are formed of a thermoplastic material; 
 a first pin surface of the first scissor slide pin of the scissor mechanism and a second pin surface of the second scissor slide pin of the scissor mechanism are formed of a thermoplastic material; 
 the scissor contact surface of the keycap is formed of a thermoplastic material; or 
 a feature surface of the at least one rattle suppression feature formed on the keycap contacting portion of the keycap bar is formed of a thermoplastic material. 
 
     
     
       8. The keyswitch mechanism of  claim 1 , wherein the rattle suppression mechanism is at least one of:
 flexible; or 
 compressible. 
 
     
     
       9. A keyswitch mechanism having reduced key rattle, comprising:
 a base having a surface; 
 a scissor mechanism slidably coupled to the base; and 
 a keycap abutting the scissor mechanism, the keycap comprising:
 a first slide groove disposed on an underside of the keycap and configured to receive a first scissor slide pin of the scissor mechanism; 
 a second slide groove disposed on the underside of the keycap and configured to receive a second scissor slide pin of the scissor mechanism, wherein the second slide groove is set apart from the first slide groove; 
 a scissor contact surface disposed between the first and the second slide grooves; and 
 a rattle suppression mechanism formed on the scissor contact surface of the keycap, the rattle suppression mechanism configured to maintain a biasing force between the keycap and a portion of the scissor mechanism abutting the keycap. 
 
 
     
     
       10. The keyswitch mechanism of  claim 9 , wherein:
 the scissor mechanism includes:
 a first scissor arm frame; 
 a second scissor arm rotatably coupled to the first scissor arm frame; and 
 first and second scissor slide pins extending from the first scissor arm frame; and 
 
 the keycap includes a first slide groove and a second slide groove, the first and second slide grooves being sized and located to slidably hold the first and second scissor slide pins of the scissor mechanism, respectively. 
 
     
     
       11. The keyswitch mechanism of  claim 10 , wherein:
 the first scissor arm frame of the scissor mechanism includes:
 a base bar coupled to the base and having a base bar axis, the first scissor arm frame aligned such that the base bar axis is substantially parallel to the surface of the base; 
 a keycap bar abutting the keycap and having a keycap bar axis substantially parallel to the base bar axis, the first and second scissor slide pins extending from the first scissor arm frame collinear to the keycap bar axis; and 
 two side bars extending between the base bar and the keycap bar; and 
 
 the first and second slide grooves of the keycap are further sized and located to slidably hold the first and second scissor slide pins of the scissor mechanism, respectively, such that the at least one rattle suppression feature formed on the scissor contact surface of the keycap is further configured to press against the keycap bar of the first scissor arm frame, thereby tightening a fit of the first and second scissor slide pins within the first and second slide grooves. 
 
     
     
       12. The keyswitch mechanism of  claim 11 , wherein at least a portion of the keycap bar of the first scissor arm frame of the scissor mechanism is elastically deformable. 
     
     
       13. The keyswitch mechanism of  claim 12 , wherein the deformable portion of the keycap bar of the first scissor arm frame of the scissor mechanism is at least one of:
 flexible; or 
 compressible. 
 
     
     
       14. The keyswitch mechanism of  claim 11 , wherein the at least one rattle suppression feature formed on the scissor contact surface of the keycap includes at least one of:
 a bump on the scissor contact surface; or 
 at least one ridge on the scissor contact surface. 
 
     
     
       15. The keyswitch mechanism of  claim 10 , wherein at least one of:
 a first contact surface of the first slide groove of the keycap and a second contact surface of the second slide groove of the keycap are formed of a thermoplastic material; 
 a first pin surface of the first scissor slide pin of the scissor mechanism and a second pin surface of the second scissor slide pin of the scissor mechanism are formed of a thermoplastic material; 
 the scissor contact surface of the keycap is formed of a thermoplastic material; or 
 a feature surface of the at least one rattle suppression feature formed on the keycap portion of the first scissor arm frame of the scissor mechanism is formed of a thermoplastic material. 
 
     
     
       16. The keyswitch mechanism of  claim 9 , wherein the rattle suppression mechanism is elastically deformable. 
     
     
       17. The keyswitch mechanism of  claim 9 , wherein the scissor contact surface is a portion of an underside of the keycap. 
     
     
       18. A keyboard having reduced key rattle, comprising:
 a backplate; 
 a wiring layer coupled to the backplate; 
 a housing coupled to the backplate and configured to hold a plurality of keys; and 
 the plurality of keys, each key including:
 a key base mechanically coupled to at least one of the backplate or the housing; 
 a dome switch mechanically coupled to the key base and electrically coupled to the wiring layer; 
 a scissor mechanism slidably coupled to the key base, the scissor mechanism including a keycap bar comprising:
 a first scissor slide pin at a first end of the keycap bar; 
 a second scissor slide pin at a second end of the keycap bar; and 
 a keycap contacting portion extending between the first and second scissor slide pins and distinct from the first and second scissor slide pins; 
 
 a keycap mechanically coupled to the dome switch and abutting the scissor mechanism, the keycap comprising:
 a first slide groove disposed on an underside of the keycap and configured to receive the first scissor slide pin; 
 a second slide groove disposed on the underside of the keycap and configured to receive the second scissor slide pin, wherein the second slide groove is set apart from the first slide groove; 
 a scissor contact surface disposed between the first and the second slide grooves; and 
 
 
 a rattle suppression mechanism formed on at least one of the keycap contacting portion of the keycap bar or the scissor contact surface of the keycap, the rattle suppression mechanism configured to maintain a biasing force between the keycap and a portion of the scissor mechanism abutting the keycap. 
 
     
     
       19. A keyswitch mechanism having reduced key rattle, comprising:
 a base having a surface; 
 a scissor mechanism slidably coupled to the base; and 
 a keycap abutting the scissor mechanism, the keycap comprising:
 a first slide groove disposed on an underside of the keycap and configured to receive a first scissor slide pin of the scissor mechanism; 
 a second slide groove disposed on the underside of the keycap and configured to receive a second scissor slide pin of the scissor mechanism, wherein the second slide groove is set apart from the first slide groove; and 
 a rattle suppression mechanism comprising:
 a first deformable contact surface formed on the first slide groove; and 
 a second deformable contact surface formed on the second slide groove; 
 
 wherein the first and second slide grooves are configured to receive the first and second scissor slide pins, respectively, such that the first and second deformable contact surfaces are deformed, thereby providing forcing a portion of the scissor mechanism against a portion of the keycap. 
 
 
     
     
       20. The keyswitch mechanism of  claim 19 , wherein the first and second deformable contact surfaces of the first and second slide grooves are at least one of:
 flexible; or 
 compressible.

Description:
TECHNICAL FIELD 
     The present invention relates to keyboards generally and keyboard keyswitch mechanisms particularly. 
     BACKGROUND 
     Electronic devices are ubiquitous in society and can be found in everything from household appliances to computers. Many electronic devices include a keyboard or keypad. These keyboards or keypads include keyswitches that may rattle undesirably at various times, such as during typing, when brushing across them, when carrying the electronic device, or when the device is subjected to any form of vibration. In any of these situations this rattling may detract from the user&#39;s perception of quality or enjoyment of the device. Additionally, key rattle may lead to wear within the keyswitch mechanism, becoming worse over time and potentially leading to further issues with the functioning of the keyboard. Thus, key rattling may generally be assumed to be a negative trait for electronic devices. 
     One source of this key rattling originates from various pieces of certain keyswitch mechanisms knocking against one another during operation or other activities, such as those described above. In many scissor-type keyswitch mechanisms, such knocking typically results from clearances between mating features of the mechanism that are included to avoid any binding of components of the switch mechanism when it is operated. 
     Sample embodiments described herein utilize various approaches to reduce key rattling within electronic devices, while maintaining non-binding operation of example keyswitch mechanisms. 
     SUMMARY 
     One sample embodiment, as described herein, is a keyswitch mechanism having reduced key rattle. The keyswitch mechanism includes: a base having a surface; a scissor mechanism slidably coupled to the base; a keycap abutting the scissor mechanism; and a rattle suppression mechanism formed on a portion of the scissor mechanism. The rattle suppression mechanism is configured to maintain force on the portion of the scissor mechanism abutting the keycap. 
     Another example embodiment of the present invention is a keyswitch mechanism having reduced key rattle. The keyswitch mechanism includes: a base having a surface; a scissor mechanism slidably coupled to the base; and a keycap abutting the scissor mechanism. The keycap includes a rattle suppression mechanism that is configured to maintain force on a portion of the scissor mechanism abutting the keycap. 
     A further example embodiment of the present invention is a keyboard having reduced key rattle. The keyboard includes: a backplate; a wiring layer coupled to the backplate; a housing coupled to the backplate and configured to hold a plurality of keys; and the plurality of keys. Each key includes: a key base mechanically coupled to at least one of the backplate or the housing; a dome switch mechanically coupled to the key base and electrically coupled to the wiring layer; a scissor mechanism slidably coupled to the key base; a keycap mechanically coupled to the dome switch and abutting the scissor mechanism; and a rattle suppression mechanism. The rattle suppression mechanism is formed on a portion of the scissor mechanism or on a portion of the keycap. The rattle suppression mechanism is configured to maintain force on the portion of the scissor mechanism abutting the keycap. 
     While multiple embodiments are disclosed, including variations thereof, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. As will be realized, the disclosure is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the present disclosure, it is believed that the embodiments are best understood from the following detailed description when read in connection with the accompanying drawing. It is emphasized that, according to common practice, the various features of the drawing are not to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Included in the drawing are the following figures: 
         FIG. 1  is a perspective drawing of an example keyboard; 
         FIG. 2  is an exploded perspective drawing of the keyboard of  FIG. 1 ; 
         FIG. 3A  is bottom plan drawing of an example keyswitch mechanism; 
         FIG. 3B  is side cut-away drawing of the example keyswitch mechanism of  FIG. 3A  along line  3 B- 3 B; 
         FIG. 3C  is front cut-away drawing of the example keyswitch mechanism of  FIGS. 3A and 3B  along line  3 C- 3 C; 
         FIG. 4A  front cut-away drawing of an example keyswitch mechanism according to an embodiment; 
         FIG. 4B  is front cut-away drawing of another example keyswitch mechanism according to an embodiment; 
         FIG. 4C  is front cut-away drawing of a further example keyswitch mechanism according to an embodiment; 
         FIG. 5A  is front cut-away drawing of an additional example keyswitch mechanism according to an embodiment; 
         FIG. 5B  is front cut-away drawing of yet another example keyswitch mechanism according to an embodiment; 
         FIG. 6A  is front cut-away drawing of yet a further example keyswitch mechanism according to an embodiment; 
         FIG. 6B  is front cut-away drawing the example keyswitch mechanism  FIG. 6A  along line  6 B- 6 B; and 
         FIG. 7  is front cut-away drawing of yet an additional example keyswitch mechanism according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  generally depicts a keyboard  100 . Although the keyboard is shown as stand-alone, it should be appreciated that the discussion herein applies generally to all keyboards, whether stand-alone or integrated into another product such as a laptop computer. Likewise, certain principles discussed herein may be applied to other input and/or output devices that include keys, such as mice, trackballs, keypads, and the like. The keyboard may be considered an “input device” and each key an “input mechanism.” 
     The keyboard  100  of  FIG. 1  includes multiple keys with keycaps  110 .  FIG. 2  generally shows an exploded view of the keyboard  100  of  FIG. 1 . As shown, the keyboard typically includes multiple layers. The individual keycaps  110  are at least partially contained within a housing or faceplate  120  that surrounds the keyboard. A backplate  130  may define a bottom portion of the housing  120 . Each key is attached to a scissor mechanism  140  that biases the key upward. As the keycap  110  of a key is pressed, the scissor collapses, permitting the key to travel downward. This motion also collapses a dome switch  150  located beneath the keyboard. The dome switches  150  all may be formed on a single dome switch layer  160 . A metal patch is formed at the top of the dome. When this patch impacts a contact on the wiring layer  170  beneath the dome. The wiring layer is connected to a microprocessor, which detects the closed circuit, registers it as a key press and generates an output or otherwise processes the closed circuit accordingly. A support layer (not shown) may be located adjacent the wiring layer to provide structural stiffness to the wiring. 
     In another embodiment, the downward motion of the key  110  pushes a plunger or other protrusion through a hole at the top of a dome  150 . The plunger, which generally has an end made of metal or that is otherwise electrically conductive, touches a contact on the bottom of the dome switch when the keyboard is sufficiently depressed. This contact creates a closed circuit with the results discussed above. 
     As also shown in  FIG. 2 , many keyboards  100  may include an illumination system that backlights one or more individual keys. To be backlit, a key generally has its legend, symbol or the like etched through the paint or other opaque surface of the keycap  110 . Oftentimes, this etching is in the shape of the letter, number or symbol corresponding to the key&#39;s input. One or more light-emitting diodes (LEDs)  180  may be positioned around the exterior of a light guide. (In some cases, one or more LEDs may also be placed in apertures within the light guide.) Light is emitted by the LEDs into the light guide  190 , which is formed from a transparent or translucent material that permits the light to propagate therethrough. A pattern of microlenses  195  may be formed on the light guide  190 . As light emitted from the LEDs  180  enters the microlenses  195 , the light is redirected to be emitted upward and out of the microlenses. 
     As noted above, one issue with keyboards and other key-based input devices used in consumer electronics is key rattle. A common source of this key rattle is space that is often left for clearance of various mechanical components to prevent binding in the keyswitch mechanism during operation of the key. This space may allow the components to move in undesired directions and/or magnitudes, producing key rattle. 
     Embodiments described herein may include a number of example embodiments designed to reduce the amount of key rattle associated with key-based input devices. Some of these example embodiments include features to apply pressure to certain mechanical components within these keyswitch mechanisms to reduce these components&#39; freedom to move in undesired directions and/or magnitudes, thus reducing, or potentially eliminating, key rattle associated with these motions. Additionally, some example embodiments include features to dampen the motion of certain mechanical components within these keyswitch mechanisms, which may also reduce, or potentially eliminate, key rattle associated with these components. One skilled in the art will understand that, although illustrated separately for clarity, many of these example embodiments may be used in conjunction to further improve the stability of the keyswitch mechanism and reduce key rattle. 
       FIGS. 3A-C  provide three orthogonal views to illustrate, in more detail than  FIG. 2 , an example basic scissor-type keyswitch mechanism that may be used in keyboards and other key-based input devices. Various sample embodiments are illustrated in  FIGS. 4A-C ,  5 A,  5 B,  6 A,  6 B, and  7 . The embodiments illustrated in detail by these figures include various example features that may be used in conjunction with the underlying scissor-type keyswitch mechanism of  FIGS. 3A-C . This example keyswitch mechanism includes: base  300 ; a scissor mechanism; and keycap  110 . It is noted that  FIG. 3A , which is a bottom plan drawing, does not include base  300 ; and  FIG. 3C , which is a front cut-away drawing, does not include the second scissor arm or pivots of the example scissor mechanism. One skilled in the art may understand that these omissions do not indicate a lack of these elements, but rather these omissions serve to reduce clutter in the figures and simplify viewing the other components of the example keyswitch mechanism. 
     The example scissor mechanism of  FIGS. 3A-C  includes: first scissor arm  302 ; second scissor arm  306 ; pivots  308  to couple first scissor arm  302  and second scissor arm  306  such that these scissor arms may rotate about this pivots; and scissor slide pins  304  to slidably couple first scissor arm  302  to keycap  110 . Pivots  308  may be bearing or they may be formed out of flexible material coupling the scissor arms. Such flexible pivots  308  may provide the bias to extend the key when keycap  110  is depressed then released. 
     Second scissor arm  306  is shown in  FIG. 3B  as having ends in contact with, but not fixedly coupled to, base  300  and keycap  110 , while first scissor arm  306  is rotatably coupled to base  300 . Thus, during operation of the example key, the ends of second scissor arm  306  may freely slide over the surfaces of both base  300  and keycap  110 . 
     First scissor arm  302  is may be formed as a frame that includes: base bar  316 , which is substantially parallel to the surface of base  300  to which it is rotatably coupled; two parallel side bars  318  extending perpendicular to base bar  316  from its ends and coupled to second scissor arm  306  by pivots  308 ; and keycap bar  320 , which extends between side bars  318  opposite base bar  316 . 
     Base bar  316  is illustrated in  FIGS. 3A-C  as including pins at either end that extend outside of the axes of side bars  318 . These pins may be used to rotatably couple first scissor arm  302  to base  300 . Alternatively, first scissor arm  302  may be rotatably coupled to base  300  at an intermediate portion of base bar  316  and these pins may be omitted. 
     Scissor pins  304  are coupled to the first frame arm at the end of keycap bar  320  and may extend outside of the axes of side bars  318  collinear to the axis of keycap bar  320 . In an example assembled key, scissor pins  304  are held in slide grooves  312  of keycap  110  and are capable of sliding within these slide grooves during operation of the key. Also during operation of the key, keycap bar  320  slides along scissor contact surface  314  of keycap  110 . 
       FIG. 3C  illustrates how clearances within an example keyswitch mechanism may lead to spaces between various mechanical components of the mechanism. For example, keycap bar  320  of first scissor arm  302  is illustrated as not being in direct contact with scissor contact surface  314  of keycap  110  and scissor pins  304  of the scissor mechanism are not in direct contact with slide groves  312  of keycap  110 . These gaps have been exaggerated for illustrative purposes, but they may represent the sort of spaces that can result from clearances between components, such as first scissor arm  302  and slide groove  312  of keycap  110  (shown in  FIG. 3B ), which are employed to avoid binding of the scissor mechanism during operation. Such gaps between keyswitch components may lead to key rattle. 
       FIG. 4A  illustrates one embodiment that may reduce key rattle in scissor-type keyswitch mechanisms by tightening a fit of scissor slide pins  304  of the scissor mechanism within slide grooves  312  of keycap  110 . 
     In the example embodiment of  FIGS. 3A-C , the use of clearances to avoid binding of the scissor mechanism leads to spaces between various mechanical components of the keyswitch mechanism. These spaces may also allow unintended movement of these components relative to each other, which is a potential source of key rattle. For example, as illustrated in  FIG. 3A , this example keyswitch mechanism may include gaps between scissor slide pins  304  of the scissor mechanism and corresponding slide grooves  312  of keycap  310 , as well as a gap between keycap bar  320  of first scissor arm  302  and scissor contact surface  314  of keycap  110 . 
     In the example embodiment of  FIG. 4A , however, keycap bar  420  of first scissor arm  402  includes a rattle suppression feature, namely arch  400 . Arch  400  of keycap bar  420  extends in a direction perpendicular to the axis of keycap bar  420  (and substantially perpendicular to the axes of the side bars of first scissor arm  402 ) to press against scissor contact surface  314  of keycap  110 . This pressure on keycap bar  420  may cause first scissor arm  402  to pivot slightly, bringing scissor slide pins  304  of the scissor mechanism into contact with the contact surfaces of slide grooves  312  of keycap  310 . In this way, arch  400  in keycap bar  420  may suppress key rattle in the example keyswitch mechanism by tightening the fit of scissor slide pins  304  within slide grooves  312 . 
     It may be noted that the use of arch  400  in keycap bar  420  as a rattle suppression mechanism in the example keyswitch mechanism of  FIG. 4A  may reduce (or possibly eliminate) the clearances between mechanical components in the mechanism. To avoid binding of the keyswitch mechanism during key operation, it may be useful for at least a portion of keycap bar  420  to be elastically deformable along the direction that the rattle suppression feature, arch  400 , extends, e.g. at least partially flattening arch  400 . This elastic deformation may be due to flexibility of keycap bar  420  along its axis or to compressibility of the material in arch  400 , or to both. 
     Such elastic deformability of keycap bar  420  may not only be useful to avoid binding of the keyswitch mechanism, but it may also be useful to allow scissor slide pins  304  of the scissor mechanism to maintain a constant contact with the contact surfaces of slide grooves  312  of keycap  310 , even when a force is exerted on a portion of keycap  110  that may cause the keycap to tilt or drop. For example, in the example key switch mechanism of  FIGS. 3A-C , key rattle may occur due to pressure on one side of the key, which may cause the other side to rise in such a way that scissor slide pins  304  may engage and disengage with the contact surfaces of slide grooves  312  or keycap bar  320  may click against scissor contact surface  314 . Alternatively, when the key is released the contact surfaces of slide grooves  312  may rebound and clicks against scissor slide pins  304 . By placing a constant bias pressure on various mechanical components of the example keyswitch mechanism in the example embodiment of  FIG. 4A , the elastic deformation of keycap bar  420  may reduce key rattle from these multiple sources. 
       FIG. 4B  illustrates another sample embodiment. In this example embodiment keycap bar  420 ′ includes bump  400 ′ as a rattle suppression feature, rather than arch  400 . This example embodiment functions similarly to the example embodiment of  FIG. 4A , reducing key rattle by tightening the fit of scissor slide pins  304  within slide grooves  312 . 
       FIG. 4C  illustrates a further sample embodiment. In this example embodiment keycap bar  420 ″ includes a series of ridges  400 ″ as a rattle suppression feature, rather than arch  400  or bump  400 ′. This example embodiment also functions similarly to the example embodiments of  FIGS. 4A and 4B , reducing key rattle by tightening the fit of scissor slide pins  304  within slide grooves  312 . 
     One skilled in the art may understand that the example embodiments of  FIGS. 4B and 4C  may have the same issue of possible binding as the example embodiment of  FIG. 4A . Thus, it may be useful for a portion of keycap bars or associated rattle suppression features to be elastically deformable in these example embodiments as well. 
       FIG. 5A  illustrates an additional sample keyswitch mechanism having reduced key rattle. In this example embodiment, scissor contact surface  514  of keycap  510  includes a rattle suppression feature, bump  500 . Bump  500  functions similarly to the example rattle suppression features of  FIG. 4A-C  (arch  400 , bump  400 ′, and ridges  400 ″), tightening the fit of scissor slide pins  304  within slide grooves  312  of keycap  510 , albeit by bump  500  on scissor contact surface  514  of keycap  510  pressing keycap bar  320  of first scissor arm  302  rather than by a rattle suppression feature on the keycap bar of the first scissor arm pressing on scissor contact surface  314  of keycap  110 . Similarly to the example embodiments of  FIGS. 4A-C , it may be useful for the rattle suppression feature, bump  500 , to be elastically deformable to avoid issues of components binding. 
       FIG. 5B  illustrates yet another example keyswitch mechanism having reduced key rattle. In this embodiment, scissor contact surface  514 ′ of keycap  510 ′ includes a rattle suppression feature, a series of ridges  500 ′. Ridges  500 ′ function similarly to bump  500  of  FIG. 5A , pressing on keycap bar  520  of first scissor arm  502  to tighten the fit of scissor slide pins  304  within slide grooves  312  of keycap  510 . 
     As in the example embodiments of  FIGS. 4A-C  and  5 A, it may be useful for the rattle suppression feature, ridges  500 ′, to be elastically deformable to avoid or prevent components from binding. The example keyswitch mechanism of  FIG. 5B  includes an additional feature that may avoid issues of components binding. In this example embodiment, at least a portion of keycap bar  520  of first scissor arm  502  is elastically deformable. This elastically deformable portion of keycap bar  520  of first scissor arm  502  may be flexible or compressible. Although not shown in  FIG. 5A , one skilled in the art may understand that this example feature may be used conjunction with the example embodiment of  FIG. 5A . 
       FIGS. 6A and 6B  illustrate yet another example keyswitch mechanism having reduced key rattle. In this example embodiment, slide grooves  612  each have body  600  and a deformable contact surface that includes compressible layer  602  and flexible layer  604 . This deformable contact surface may allow scissor contact surface  314  of keycap  110  to be held in contact with keycap bar  320  of first scissor arm  302  without binding the scissor mechanism. Scissor slide pins  304  are pressed against the respective deformable contact surfaces of the slide grooves  614  with sufficient pressure to deform the deformable contact surfaces. As in the previous described example embodiments, the tightening fitting of the scissor mechanism components generally leads to reduced key rattle. 
     In this example embodiment, compressible layer  602  may absorb the bulk of the pressure from scissor slide pins  304 . Flexible layer  604  may serve to protect compressible layer  602 . Alternatively (or additionally), flexible layer  604  may provide a lower friction layer to further avoid binding of the scissor mechanism. It is noted that, although illustrated as a two layer composite, the example deformable contact surface of slide groves  612  may be formed of a single compressible layer. 
       FIG. 7  illustrates yet a further example keyswitch mechanism having reduced key rattle. In this example embodiment, slide grooves  712  are able to deform by flexing. As in the example embodiment of  FIGS. 6A and 6B , this deformation of may slide grooves  712  allow scissor contact surface  314  of keycap  110  to be held in contact with keycap bar  320  of first scissor arm  302  without binding the scissor mechanism. Scissor slide pins  304  are pressed against the respective slide grooves  714  with sufficient pressure to slightly flex them. As in the previous described example embodiments, the tightening fitting of the scissor mechanism components may lead to reduced key rattle. 
     It is noted that tightening the fit of the scissor slide pins within the slide grooves of the keycap, as illustrated in each of the preceding example embodiments, may, in addition to reducing key rattle in the example keyswitch mechanism, also lead to increased friction between components of the keyswitch mechanism as they slide during key operation. In particular, this tightened fit may increase friction between the surface of the keycap bar and scissor contact surface and between the surface of scissor slide pins and the surface of slide grooves of the keycap. Therefore, it may be useful for one or more of these surfaces to be formed of a thermoplastic, such as nylon, high-density polyethylene (HDPE), or polytetrafluoroethylene (PTFE), to reduce the coefficient of friction between these surfaces. 
     While the present disclosure has been described with reference to various embodiments, it will be understood that these embodiments are illustrative and that the scope of the disclosure is not limited to them. Many variations, modifications, additions, and improvements are possible. More generally, embodiments in accordance with the present disclosure have been described in the context of particular embodiments. Functionality may be separated or combined in procedures differently in various embodiments of the disclosure or described with different terminology. These and other variations, modifications, additions, and improvements may fall within the scope of the disclosure as defined in the claims that follow.

Metadata:
Filing Date: 20130310
Publication Date: 20150623
Grant Date: 20150623
Priority Date: 20130310
Inventors: WELCH HAROLD J.
LEONG CRAIG C.
NIU JAMES J.
BROCK JOHN M.
HENDREN KEITH J.
COISH ROBERT L.
MURPHY ROBERT S.
YARAK, III WILLIAM P.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H3/125", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2221/062", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/125", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2221/062", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/058", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/14", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/12", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2221/062", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/125", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 51486472