Patent Publication Number: US-11380494-B2

Title: Method for assembling keyswitch device

Description:
RELATED APPLICATIONS 
     The present application is a Divisional Application of the U.S. application Ser. No. 15/964,015, filed Apr. 26, 2018, which claims priority to Taiwan Application Serial Number 106145127, filed Dec. 21, 2017, all of which are herein incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a method for assembling a keyswitch device. 
     Description of Related Art 
     A detachable 2-in-1 laptop not only has the advantages of slimness and lightness of a tablet, but also has the usefulness of a traditional laptop when being equipped with a keyboard that is dismantlable from the tablet and rotatable to adjust a tilt angle with the tablet. To connect the keyboard to the tablet, a rotatable electrical connector is disposed on the keyboard correspondingly. 
     There are several designs in the market for conventional rotatable electrical connectors currently on the market generally adopt the following few designs. The first design is to dispose an electrical connector on a leather material covering a keyboard. Because the leather material is bendable and elastic, the electrical connector is rotatable. The second design is a rotatable-shaft type that adds rotatable shaft structures on both sides of a base of an electrical connector, so as to pivotally connect with respective sides of a keyboard. 
     However, in the aforementioned first design, the leather material may be deformed or peeled off from a keyboard surface due to pulling after a long-term rotation. An electrical connector adopting the aforementioned second design does not have a leather appearance, and the structure of the shaft can be seen through a gap between the keyboard and the electrical connector, thus affecting the product appearances. 
     Consequently, how to provide a keyswitch device to the aforementioned issues is one of the topics desired by the research and development of the industry. 
     SUMMARY 
     In view of the foregoing, one of the objects of the present invention is to provide a keyswitch device that can effectively prevent leather from being deformed or peeled off due to pulling and can improve the texture of the appearance of the keyswitch device. 
     To achieve the objective stated above, in accordance with an embodiment of the present invention, a keyswitch device includes a main body, an engaging structure, a connection base, and a flexible covering layer. The main body has a surface and a recess communicating with the surface. The engaging structure is connected to the main body and partially protrudes into the recess. The connection base includes an engaging portion. The engaging portion is rotatably engaged with the engaging structure. The flexible covering layer includes a first covering portion and a second covering portion. The first covering portion is connected to the surface. The second covering portion is connected to the connection base. 
     In one or more embodiments, the connection base includes a first cover body and a second cover body connected to the first cover body. The second covering portion is sandwiched between the first cover body and the second cover body, and the engaging portion is connected to the second cover body. 
     In one or more embodiments, the engaging portion is a pivot. The engaging structure includes a hook portion. The hook portion protrudes into the recess and has a concave surface. The pivot rotatably abuts against the concave surface. 
     In one or more embodiments, the engaging structure further includes a fixing portion. The fixing portion is fixed to the main body and is connected to the hook portion. 
     In one or more embodiments, the fixing portion is substantially parallel to the surface of the main body. The hook portion is extended from the fixing portion and is bent toward a bottom of the recess. 
     In one or more embodiments, the engaging portion is a pivot. The engaging structure has a shaft hole that is located inside the recess and pivotally connected to the pivot. 
     In one or more embodiments, the main body includes a first housing and a second housing. The first housing has the surface. The second housing is connected to the first housing and constitutes the recess with the first housing. 
     The engaging portion is restricted between the engaging structure and the second housing. 
     In one or more embodiments, the keyswitch device further includes a flexible bottom layer connected to the second housing. 
     In one or more embodiments, the engaging structure is disposed inside the main body. 
     In one or more embodiments, the first covering portion and the second covering portion are connected to or separated from each other. 
     To achieve the aforementioned objective, in accordance with an embodiment, a method for assembling a keyswitch device includes: connecting a first covering portion to a surface of a first housing; connecting a second covering portion to a connection base including an engaging portion; rotatably engaging the engaging portion with an engaging structure; connecting the engaging structure to the first housing; and fixing a second housing to the first housing such that the first housing and the second housing constitute a recess communicating with the surface. The engaging structure partially protrudes into the recess. 
     In one or more embodiments, the first housing has an opening on the surface. The method further includes: connecting a flexible covering layer to the surface to cover the opening; and cutting the flexible covering layer substantially along the opening to form the first covering portion and the second covering portion. 
     In one or more embodiments, the method further includes separating the first covering portion and the second covering portion. 
     In one or more embodiments, the first housing includes a first portion and a second portion. The first portion has the surface. The step of connecting the engaging structure to the first housing includes connecting the engaging structure to the first portion of the first housing. 
     In one or more embodiments, the step of connecting the engaging structure to the first portion is performed before the step of connecting the first covering portion to the surface. 
     In one or more embodiments, the connection base includes a first cover body and a second cover body which is connected to the engaging portion. The step of connecting the second covering portion to the connection base includes: connecting the first cover body to the second covering portion; and connecting the second cover body to the second covering portion. The connected second covering portion is sandwiched between the first cover body and the second cover body. 
     In one or more embodiments, the step of rotatably engaging the engaging portion with the engaging structure is performed before the step of connecting the second cover body to the second covering portion. 
     In one or more embodiments, the method further includes connecting a flexible bottom layer to the second housing. 
     In one or more embodiments, the engaging portion is a pivot. The engaging structure includes a hook portion and a fixing portion connected to each other. The hook portion has a concave surface. The step of rotatably engaging the engaging portion with the engaging structure includes rotatably engaging the engaging portion with the concave surface. The step of connecting the engaging structure to the first housing includes fixing the fixing portion to the first housing. 
     In one or more embodiments, the engaging portion is a pivot. The engaging structure has an inlet and a shaft hole communicating with each other. The inlet shrinks inward relative to the shaft hole. The step of rotatably engaging the engaging portion with the engaging structure includes pivotally connecting the pivot to the shaft hole through the inlet. 
     In sum, in the keyswitch device of the present invention, by disposing an engaging structure inside a main body for connecting with a connection base, and protruding the engaging structure into a recess of the main body, the problem of the conventional shaft structures that are exposed outward can be prevented, and the texture of the appearance of the keyswitch device can be effectively improved. In addition, by using the engaging structure, the problem that the flexible covering layer may be deformed or peeled off from the main body due to pulling caused by long-term rotation of the connection base relative to the main body can be resolved, in which the connection base is connected to the flexible covering layer. 
     The foregoing descriptions are provided only to explain the problem to solve, technical means to solve the problem and its efficacy, and so on, of the present invention. Specific details of the present invention will be introduced in detail in the embodiments and the related drawings below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To make the objectives, features, advantages, and examples of the present invention, including those mentioned above and others, more comprehensible, descriptions of the accompanying drawings are provided as follows. 
         FIG. 1  illustrates a partial perspective view of a keyswitch device in accordance with an embodiment of the present invention. 
         FIG. 2A  illustrates a partial cross-sectional view of the keyswitch device taken along line  2 A- 2 A shown in  FIG. 1 , in which a connection base is located inside a recess. 
         FIG. 2B  is a schematic diagram of the structure shown in  FIG. 2A  after rotation, in which the connection base partially protrudes out of the recess. 
         FIG. 3A  illustrates a perspective view of some elements of a keyswitch device in accordance with an embodiment of the present invention. 
         FIG. 3B  is an exploded view of the elements shown in  FIG. 3A . 
         FIG. 4  illustrates a partial cross-sectional view of a keyswitch device in accordance with another embodiment of the present invention. 
         FIG. 5  illustrates a partial cross-sectional view of a keyswitch device in accordance with another embodiment of the present invention. 
         FIG. 6A  to  FIG. 6E  are schematic diagrams showing a method for assembling a keyswitch device at various assembly stages in accordance with an embodiment of the present invention. 
         FIG. 6F  illustrates a schematic diagram showing a method for assembling a keyswitch device at one of assembly stages in accordance with another embodiment of the present invention. 
         FIG. 7  illustrates a flow chart of a method for assembling a keyswitch device in accordance with an embodiment of the present invention. 
         FIG. 8A  to  FIG. 8E  are schematic diagrams showing a method for assembling a keyswitch device at various assembly stages in accordance with another embodiment of the present invention. 
         FIG. 9  illustrates a flow chart of a method for assembling a keyswitch device in accordance with another embodiment of the present invention. 
         FIG. 10  is a partial perspective view of the keyswitch device shown in  FIG. 8E . 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments of the present invention, examples of which are illustrated in the accompanying drawings, will be disclosed below. For the sake of clarity, various practical details will be explained in the following descriptions. However, it should be understood that these practical details should not be used to limit the present invention. In other words, these practical details are unnecessary in certain embodiments of the present invention. Moreover, to simplify the drawings, some well-known structures or elements will be illustrated schematically in the drawings. 
     Please refer to  FIG. 1  to  FIG. 2B .  FIG. 1  illustrates a partial perspective view of a keyswitch device  100  in accordance with an embodiment of the present invention.  FIG. 2A  illustrates a partial cross-sectional view of the keyswitch device taken along line  2 A- 2 A shown in  FIG. 1 . In  FIG. 2A , a connection base  141  is located inside a recess  113 .  FIG. 2B  is a schematic diagram of the structure shown in  FIG. 2A  after rotation. In  FIG. 2B , the connection base  141  partially protrudes out of the recess  113 . 
     As shown in  FIG. 1  to  FIG. 2B , in the present embodiment, the keyswitch device  100  includes a main body, an engaging structure  130 , an electrical connector  140 , a flexible covering layer  150 , and a flexible bottom layer  160 . The main body includes a first housing  110  and a second housing  120 . The main body has a surface  111 , an opening  112 , and a recess  113  communicating with the surface  111  through the opening  112 . An engaging structure  130  is connected to the main body and partially protrudes into the recess  113 . The electrical connector  140  includes a connection base  141 , and the connection base  141  includes an engaging portion  141   c  rotatably engaged with the engaging structure  130 . The flexible covering layer includes a first covering portion  151  and a second covering portion  152 . The first covering portion  151  is connected to the surface  111 , and the second covering portion  152  is connected to the connection base  141 . The flexible bottom layer  160  is connected with and covers the side of the second housing  120  located away from the first housing  110 . 
     In the present embodiment, the flexible covering layer  150  and the flexible bottom layer  160  may be a leather layer, a leather case layer, or a soft layer, but the present invention is not limited in this regard. 
     In the present embodiment, hot-press bonding, hot melting, gluing, and other fixing method may be adopted to connect the flexible covering layer  150  to the main body and the connection base  141 , and to connect the flexible bottom layer  160  to the main body. 
     In some embodiments, the first housing  110  has the opening  112  and the surface  111 . The second housing  120  is connected to the first housing  110 , and the first housing  110  and the second housing  120  constitutes the recess  113 . 
     Furthermore, as shown in  FIG. 2A  and  FIG. 2B , the connection base  141  includes a first cover body  141   a  and a second cover body  141   b  connected to the first cover body  141   a . The second covering portion  152  is sandwiched between the first cover body  141   a  and the second cover body  141   b . The engaging portion  141   c  is connected to the second cover body  141   b . This structural configuration can effectively reduce the area of the connection base  141  exposed out of the flexible covering layer  150  (i.e., reduce the area of the connection base  141  that is not covered by the flexible covering layer  150 ). As a result, compared to the conventional electrical connectors that are not covered by leathers, the keyswitch device  100  of the present embodiment can effectively improve the texture of the product appearance. 
     In some embodiments, the engaging portion  141   c  is a pivot, as show in  FIG. 2A  and  FIG. 2B . The engaging structure  130  includes a fixing portion  131  and a hook portion  132 . The fixing portion  131  is fixed to the main body and connected to the hook portion  132 . In some embodiments, the fixing portion  131  of the engaging structure  130  is fixed to the first housing  110  of the main body and is located between the first housing  110  and the second housing  120 . The engaging structure  130  may be fixed to the first housing  110  by bonding or gluing, or by fitting with hooking, locking, interfering, or fixing components, but the present invention is not limited in this regard. The hook portion  132 , which has a concave surface  132   a  is extended from the fixing portion  131 , and protrudes into the recess  113 . The pivot rotatably abuts against the concave surface  132   a.    
     In some embodiments, the connection interface of the first covering portion  151  and the second covering portion  152  is substantially located at an edge of the opening  112  of the first housing  110 , as shown in  FIG. 2A  and  FIG. 2B , but the present invention is not limited in this regard. In addition, the hook portion  132  of the engaging structure  130  is substantially aligned with the edge of the opening  112 . With the structural configuration stated above, the connection base  141  can rotate relative to the edge of the opening  112 , while enabling the second covering portion  152  to rotate relative to the first covering portion  151 . 
     In some embodiments, the fixing portion  131  is substantially parallel to the surface  111  of the first housing  110  of the main body. The hook portion  132  is extended from the fixing portion  131  and is bent toward a bottom of the recess  113 . With this structural configuration, the engaging portion  141   c  of the connection base  141  can be stably restricted between the engaging structure  130  and the second housing  120 , thereby effectively preventing the engaging portion  141   c  from being detached from the engaging structure  130 , in which the detachment of the engaging portion  141   c  from the engaging structure  130  may cause the detachment of the connection base  141  from the recess  113 . 
     Please refer to  FIG. 3A  and  FIG. 3B .  FIG. 3A  illustrates a perspective view of some elements of a keyswitch device in accordance with an embodiment of the present invention.  FIG. 3B  is an exploded view of the elements of the keyswitch device shown in  FIG. 3A . 
     As shown in  FIG. 3A  and  FIG. 3B , in the present embodiment, the electrical connector  140  further includes an electrical connection module  142 , magnetic members  143 , and a transmission route  144 . The electrical connection module  142  and the magnetic members  143  are disposed inside the connection base  141  (i.e., accommodated in the space between the first cover body  141   a  and the second cover body  141   b ), and the electrical connection module  142  passes through the second covering portion  152  of the flexible covering layer  150 . The electrical connection module  142  is partially exposed out of the first cover body  141   a  and is configured to be electrically connected with an external electronic device (not shown, such as a tablet). The two magnetic members  143  are disposed on both sides of the electrical connection module  142 , and are configured to attract magnets disposed inside the external electronic device (not shown), thereby enabling the external electronic device to stably abut against the connection base  141 , thus establishing a more stable electrical connection between the electrical connection module  142  and the external electronic device. The transmission route  144  electrically connects the electrical connection module  142  and the electronic components disposed inside the main body (such as a processor). 
     In some embodiments, the electrical connection module  142  is a pogo pin connector, but the present invention is not limited in this regard. In some embodiments, the transmission route  144  is disposed on a flexible circuit board, but the present invention is not limited in this regard. 
     It is noted that, in some embodiments, the connection base  141  of the electrical connector  140  includes engaging portions  141   c , and the engaging structure  130  correspondingly includes hook portions  132  that can be respectively engaged with the engaging portions  141   c , as shown in  FIG. 3B . In other words, the engaging portions  141   c  and the hook portions  132  can form plural engaging combinations. In addition, these engaging combinations are uniformly and substantially equidistantly distributed along the interface between the second cover body  141   b  and the engaging structure  130 . With this structural configuration, the force exerted on the second cover body  141   b  and the engaging structure  130  can be uniformly shared when the second cover body  141   b  and the engaging structure  130  are rotated relative to each other, thereby enhancing the stability of the pivotal connection between the second cover body  141   b  and the engaging structure  130 . Thus, deformation at the interface between the second cover body  141   b  and the engaging structure  130  due to pulling can be effectively prevented, thereby solving the problem that the leather of the second covering portion  152  is peeled off. 
     In some embodiments, the engaging structure  130  is disposed inside the main body, as show in  FIG. 2A  and  FIG. 2B , but the present invention is not limited in this regard. Please refer to  FIG. 4 , which illustrates a partial cross-sectional view of a keyswitch device  200  in accordance with another embodiment of the present invention. In the present embodiment, as shown in  FIG. 4 , the keyswitch device  200  includes a main body, an engaging structure  130 , an electrical connector  140 , and a flexible covering layer  150 . The engaging structure  130 , the electrical connector  140 , and the flexible covering layer  150  in the present embodiment are the same as those of the embodiment shown in  FIG. 2A . Therefore, references can be made to the foregoing related descriptions, and details are not described herein again. It should be noted that differences between the present embodiment and the embodiment shown in  FIG. 2A  are that the structure of the first housing  110  of the main body and the location of the engaging structure  130  have been modified. 
     In the present embodiment, the engaging structure  130  is attached to a surface  211  of a first housing  210  that is located away from the second housing  120 . In the present embodiment, the top surface of the engaging structure  130  and the surface  211  of the first housing  210  are coplanar, but the present invention is not limited in this regard. In practical applications, a step may exist between the top surface of the engaging structure  130  and the surface  211  of the first housing  210 . 
     Please refer to  FIG. 5 , which illustrates a partial cross-sectional view of a keyswitch device  300  in accordance with another embodiment of the present invention. In the present embodiment, the keyswitch device  300  includes a main body, an engaging structure  330 , an electrical connector  140 , and a flexible covering layer  150 . The main body, the electrical connector  140 , and the flexible covering layer  150  in the present embodiment are the same as those of the embodiment shown in  FIG. 2A . Therefore, references can be made to the foregoing related descriptions, and details are not described herein again. It should be noted that a difference between the present embodiment and the embodiment shown in  FIG. 2A  is that the engaging structure  130  has been modified. 
     In the present embodiment, the engaging structure  330  has an inlet  331  and a shaft hole  332  communicating with each other. The shaft hole  332  is located inside the recess  113  and is pivotally connected with the pivot. The inlet  331  shrinks inward relative to the shaft hole  332 . In other words, in the cross-sectional view shown in  FIG. 5 , a shape of the combination of the inlet  331  and the shaft hole  332  is similar to a shape of a droplet-shaped hole. Consequently, an assembler may press the pivot to enter the shaft hole  332  through the inlet  331 , so as to complete the assembly of the keyswitch device, in which the shrinking inlet  331  can prevent the pivot from escaping from the shaft hole  332 . 
     In some embodiments, the inlet  331  of the engaging structure  330  is located on the side of the engaging structure  330  that faces toward the first housing  110  and faces away from the second housing  120 , so as to facilitate the connection base  141  into the recess  113  through the opening  112  for assembly, but the present invention is not limited in this regard. In some other embodiments, the inlet  331  of the engaging structure  330  may also be located on the side of the engaging structure  330  that facies toward the second housing  120  and faces away from the first housing  110 , so as to stably restrict the pivot between the engaging structure  330  and the second housing  120 , thereby effectively preventing the pivot from being detached from the engaging structure  330 , in which the detachment of the pivot from the engaging structure  330  may cause the detachment of the connection base  141  from the recess  113 . 
     Please refer to  FIG. 6A  to  FIG. 6E , which are schematic diagrams showing a method for assembling a keyswitch device at various assembly stages in accordance with an embodiment of the present invention. As shown in  FIG. 6A  to  FIG. 6E , with references to  FIG. 2A  and  FIG. 2B , in the present embodiment, the method can include steps S 101  to S 107 . 
     In step S 101 , a first covering portion  151  is connected to a surface  111  of a first housing  110  (referring to  FIG. 6A ). 
     In step S 102 , a second covering portion  152  is connected to a connection base  141 , in which the connection base  141  includes an engaging portion  141   c  (referring to  FIG. 6A ). In some embodiments, step S 102  may be performed before step S 101 . 
     In some embodiments, the connection base  141  includes a first cover body  141   a  and a second cover body  141   b  connected with the engaging portion  141   c . The step of connecting the second covering portion  152  to the connection base  141  (i.e., S 102 ) includes steps S 102   a  and S 102   b.    
     In step S 102   a , the first cover body  141   a  is connected to the second covering portion  152 . 
     In step S 102   b , the second cover body  141   b  is connected to the second covering portion  152 . As a result, the connected second covering portion  152  is sandwiched between the first cover body  141   a  and the second cover body  141   b.    
     In some embodiments, the step of connecting the second cover body  141   b  to the second covering portion  152  (i.e., S 102   b ) can be performed before the step of connecting the first cover body  141   a  to the second covering portion  152  (i.e., S 102   a ). 
     In some embodiments, the first housing  110  has an opening  112  on the surface  111 . The method further includes steps S 103   a  and S 103   b.    
     In step S 103   a , a flexible covering layer  150  is connected to the surface  111  to cover the opening  112  (referring to  FIG. 6A ). In some embodiments, performing step S 103   a  means that step S 101  is performed. 
     In step S 103   b , the flexible covering layer  150  is substantially cut along the opening  112  to form the first covering portion  151  and the second covering portion  152  (referring to  FIG. 6B ). 
     In step S 104 , the engaging portion  141   c  is rotatably engaged with the engaging structure  130  (referring to  FIG. 6C ). 
     In step S 105 , the engaging structure  130  is connected to the first housing  110  (referring to  FIG. 6D ). 
     In some embodiments, the engaging portion  141   c  is a pivot. The engaging structure  130  includes a hook portion  132  and a fixing portion  131  connected to each other. The hook portion  132  has a concave surface  132   a . The step of rotatably engaging the engaging portion  141   c  with the engaging structure  130  (i.e., S 104 ) includes step S 104   a . The step of connecting the engaging structure  130  to the first housing  110  (i.e., S 105 ) includes step S 105   a.    
     In step S 104   a , the engaging portion  141   c  is rotatably abutted against the concave surface  132   a.    
     In step S 105   a , the fixing portion  131  is fixed to the first housing  110 . 
     It should be noted that, in the present embodiment, the engaging structure  130  may be fixed to the first housing  110  by bonding or gluing, or by fitting with hooking, locking, interfering, or fixing components, but the present invention is not limited in this regard. 
     In some other embodiments, with reference to  FIG. 5 , the engaging portion  141   c  is a pivot. An engaging structure  330  has an inlet  331  and a shaft hole  332  communicating with each other. The inlet  331  shrinks inward relative to the shaft hole  332 . The step of rotatably engaging the engaging portion  141   c  with the engaging structure  330  (i.e., S 104 ) includes step S 104   b.    
     In step S 104   b , the pivot is pivotally connected to the shaft hole  332  through the inlet  331 . 
     In step S 106 , a second housing  120  is fixed to the first housing  110 , such that the first housing  110  and the second housing  120  constitute a recess  113  communicating with the surface  111  (referring to  FIG. 6E ). The engaging structure  130  partially protrudes into the recess  113 . 
     In step S 107 , a flexible bottom layer  160  is connected to and covers the side of the second housing  120  located away from the first housing  110  (referring to  FIG. 6E ). 
     It should be noted that, in the present embodiment, hot-press bonding, hot melting, gluing, and other fixing methods may be adopted to connect the flexible covering layer  150  to the first housing  110  and the connection base  141 , and to connect the flexible bottom layer  160  to the second housing  120 . 
     The keyswitch device  100  as shown in  FIG. 2A  and  FIG. 2B  can be obtained by performing steps S 101  to S 107  stated above. 
     Please refer to  FIG. 6F , which is a schematic diagram showing a method for assembling a keyswitch device at one of assembly stages in accordance with another embodiment of the present invention. Compared to the method shown in  FIG. 6A  to  FIG. 6E , the method of the present embodiment may further include step S 108 . 
     In step S 108 , the first covering portion  151  and the second covering portion  152  are separated. In some embodiments, S 108  can be performed before or after any one of the steps S 101  to S 107 . 
       FIG. 7  illustrates a flow chart of a method for assembling a keyswitch device in accordance with an embodiment of the present invention. The method shown in  FIG. 7  can be more easily understood by referring back to  FIG. 6A  to  FIG. 6F . 
     Please refer to  FIG. 8A  to  FIG. 8E , which are schematic diagrams showing a method for assembling a keyswitch device at various assembly stages in accordance with another embodiment of the present invention. As shown in  FIG. 8A  to  FIG. 8E , in the present embodiment, the method may include steps S 201  to S 207 . It should be noted that, in the present embodiment, a first housing  410  includes a first portion  410   a  and a second portion  410   b . The first portion  410   a  has a surface  410   a   1 . The first portion  410   a  and the second portion  410   b  constitute an opening  412 . 
     In step S 201 , a flexible covering layer  460  is connected to a surface of the second portion  410   b  (referring to  FIG. 8A ). 
     In step S 202 , an engaging portion  141   c  is rotatably engaged with an engaging structure  130  (referring to  FIG. 8B ). 
     In step S 203 , the engaging structure  130  is connected to the first portion  410   a  (referring to  FIG. 8C ). 
     It should be noted that, in the present embodiment, the engaging structure  130  may be fixed to the first portion  410   a  by bonding or gluing, or by fitting with hooking, locking, interfering, or fixing components, but the present invention is not limited in this regard. 
     In step S 204 , a first covering portion  451  is connected to the surface  410   a   1  of the first portion  410   a  (please refer to  FIG. 8D ). 
     In step S 205 , a second covering portion  452  is connected to a connection base  141  (referring to  FIG. 8D ). In some embodiments, the connection base  141  includes a first cover body  141   a  and a second cover body  141   b , connected to the engaging portion  141   c . The step of connecting the second covering portion  452  to the connection base  141  (i.e., step S 205 ) may further include steps S 205   a  and S 205   b.    
     In step S 205   a , the first cover body  141   a  is connected to the second covering portion  452 . 
     In step S 205   b , the second cover body  141   b  is connected to the second covering portion  452 . The connected second covering portion  452  is sandwiched between the first cover body  141   a  and the second cover body  141   b.    
     In some embodiments, the step of connecting the second cover body  141   b  to the second covering portion  452  (i.e., S 205   b ) is performed before the step of connecting the first cover body  141   a  to the second covering portion  452  (i.e., S 205   a ). 
     In some embodiments, the step of rotatably engaging the engaging portion  141   c  with the engaging structure  130  (i.e., S 202 ) is performed after the step of connecting the second cover body  141   b  to the second covering portion  452  (i.e., S 205   b ). 
     In step S 206 , a second housing  120  is fixed to the first housing  410 , such that the first housing  410  and the second housing  120  constitute a recess  113  communicating with the surface  410   a   1  (referring to  FIG. 8E ). The engaging structure  130  partially protrudes into the recess  113 . 
     In step S 207 , a flexible bottom layer  160  is connected to and covers the side of the second housing  120  located away from the first housing  410  (referring to  FIG. 8E ). 
     In some embodiments, as shown in  FIG. 8A  and  FIG. 8B , step S 201  is performed after step S 202 , but the present invention is not limited in this regard. In practical applications, S 201  can be performed before or after any one of the steps S 202  to S 207 . 
     It is noted that, in the present embodiment, hot-press bonding, hot melting, gluing, and other fixing methods may be adopted to connect the flexible covering layer  450  to the first portion  410   a  and the connection base  141 , to connect the flexible covering layer  450  to the second portion  410   b , and to connect the flexible bottom layer  160  to the second housing  120 . 
       FIG. 9  illustrates a flow chart of a method for assembling a keyswitch device in accordance with another embodiment of the present invention. The method shown in  FIG. 9  can be more easily understood by referring back to  FIG. 8A  to  FIG. 8E . 
     Please refer to  FIG. 10 , which illustrates a partial perspective view of the keyswitch device  400  shown in  FIG. 8E . The keyswitch device  400  as shown in  FIG. 8E  and  FIG. 10  can be obtained by performing steps S 201  to S 207  shown in  FIG. 9 . 
     Apparently, from the above description, in the keyswitch device of the present invention, by disposing the engaging structure inside the main body for engaging with the engaging portion, and protruding the engaging structure into the recess of the main body, the problem of the conventional shaft structures exposed outward can be prevented, and thus the texture of the product appearance can be effectively improved. In addition, in the keyswitch device in which the electrical connector is attracted to magnets disposed on an external electronic device, the electrical connection module can establish stable electrical connection with the external electronic device, and the connection base is rotatably engaged with the engaging structure thereby enabling the external electronic device to be rotatable. Moreover, by using this engaging structure, the problem that the flexible covering layer is deformed or peeled off from the main body due to pulling caused by long-term rotation of the connection base relative to the main body can be resolved, in which the connection base is connected to the flexible covering layer. 
     Though the invention has been disclosed by the above embodiments, the disclosed embodiments are not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and the scope of the disclosure. Therefore, the protective scope of the disclosure shall be the scope of the claim as attached.