Abstract:
A cover with an angle adjustable standing slot is used to place an electronic device. The cover includes a keyboard, a cradle with a standing slot, a torque structure, and an elastic structure. The electronic device can be placed to the standing slot. A user can push the electronic device to rotate the cradle and the cradle would force the torque structure and the elastic structure to move. The electronic device can be stopped at an appropriate viewing angle, because the force between the electronic device, the torque structure, and the elastic structure are balanced. Additionally, the user can use the keyboard on the cover to type or edit documents anytime and anywhere.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 103101436 filed in Taiwan, R.O.C. on 2014 Jan. 15, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     1. Technical Field 
     The disclosure relates to a protecting cover, and particularly to a cover with angle adjustable standing slot applicable to a handheld electronic device in which the tilting angle between the cover and the electronic device is adjustable upon the electronic device is assembled on the cover. 
     2. Related Art 
     In addition to being interfaces for browsing webpages, for some people tablet PCs are also provided for editing documents. However, in contrast with a physical keyboard, inputting a great deal of information through a virtual keyboard provided on the tablet PC is slower and inconvenient, requiring a physical keyboard connected with the tablet PC being developed, in order to improve significantly the convenience with which a great deal of information must be inputted into the tablet PC. Currently, a cover with physical keyboard assembled is commercially available, so that the cover protects the tablet PC as long as carrying the physical keyboard, and a user can use the physical keyboard on the cover to type or edit documents anytime and anywhere. 
     However, the angle between the conventional cover with physical keyboard and the tablet PC is fixed. That is, when the tablet PC is connected or assembled on the fastening structure of the conventional cover, the angle between the conventional cover and the tablet PC cannot be adjusted. Consequently, since the user cannot adjust the angle between the cover and the tablet PC according to their viewing angle, they must change their postures to operate or watch the tablet PC; however, improper postures result in health complaints after extended use. 
     SUMMARY 
     In view of this, the disclosure provides a cover with angle adjustable standing slot used to place an electronic device. The cover includes a base, a cradle, at least one driven member, at least one torque structure and at least one elastic structure. The base has a receiving groove. The cradle is rotatably assembled on the base and rotatable between an initial position and an adjusted position. The at least one driven member is assembled in the receiving groove and connected to the cradle. The at least one torque structure is also assembled in the receiving groove and connected to the at least one driven member. The at least one elastic structure is assembled in the receiving groove as well and connected to the at least one driven member. 
     When the electronic device is placed in the cradle with an outer force being applied to the electronic device so as to drive the cradle to rotate from the initial position to the adjusted position, the cradle pushes the at least one driven member to drive the at least one torque structure and the at least one elastic structure. Meanwhile, since the force balance is formed among the at least one torque structure, the at least one elastic structure and the electronic device, the cradle is secured at the adjusted position when the contact force is removed. 
     As described previously, since the electronic device is secured at the required angle by the force balancing among the torque structure, the elastic structure and the electronic device, the required angle is adjustable according to user requirements within an interval. Additionally, since the angle adjustment is achieved by means of force balancing rather than means of engaging structure, the required angle can be adjusted slightly rather than being fixed at a preset angle. Again, since the angle adjustment is achieved by means of force balancing, when the user detaches the electronic device from the cradle, the elastic force of the elastic structure drives the cradle to move resiliently. 
     The detailed features and advantages of the disclosure are described below in great detail through the following embodiments, the content of the detailed description is sufficient for those skilled in the art to understand the technical content of the disclosure and to implement the disclosure there accordingly. Based on the content of the specification, the claims, and the drawings, those skilled in the art can easily understand the relevant objectives and advantages of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will become more fully understood from the detailed description given herein below for illustration only and thus not limitative of the disclosure, wherein: 
         FIG. 1  is a perspective view of a cover with angle adjustable standing slot of a first embodiment of the disclosure; 
         FIG. 2  is an exploded view of the cover with angle adjustable standing slot of the first embodiment of the disclosure; 
         FIG. 3  is a top view of the cover with angle adjustable standing slot of the first embodiment of the disclosure; 
         FIG. 4  is a cross-sectional view along line A-A shown in  FIG. 3 ; 
         FIG. 5  is a schematic view for showing the applied force of the cover with angle adjustable standing slot; 
         FIG. 6  is an exploded view of a cover with angle adjustable standing slot of a second embodiment of the disclosure; 
         FIG. 7  is a top view of the cover with angle adjustable standing slot of the second embodiment of the disclosure; and 
         FIG. 8  is a cross-sectional view along line B-B shown in  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     Please refer to  FIG. 1  and  FIG. 2 , which are respectively a perspective view and an exploded view of a cover with angle adjustable standing slot of a first embodiment of the disclosure. The cover with angle adjustable standing slot can be used to place an electronic device  10 . The cover includes a base  20 , a cradle  30 , two driven members  40 , a torque structure  50  and two elastic structures  60 . The electronic device  10  can be a tablet PC, a cell phone or other handheld electronic apparatuses. The base  20  has a receiving groove  21  and a keyboard  22 . The two driven members  40 , the torque structure  50  and the two elastic structures  60  are assembled in the receiving groove  21 . The cradle  30  is rotatably assembled on the base  20  and rotatable between an initial position and an adjusted position. The number of the driven members  40  and that of the elastic structures  60  can be one or more than one; in this embodiment, two driven members  40  and two elastic structures  60  are applied. 
     As shown in  FIG. 2 , the cradle  30  is pivotally assembled on the base  20  via the two pivoting shafts  31 , so that the cradle  30  is rotatable using the two pivoting shafts  31  as rotating axis. As shown in  FIG. 1 , when a user tends to stand up and tilt the electronic device  10  for watching or inputting information, the user assembles the electronic device  10  in the cradle  30 , so that the electronic device  10  is disposed in the initial position. In order to assemble the electronic device  10  in the cradle  30 , the cradle  30  has a standing slot  32  recessed therein, so that the electronic device  10  is engaged in the standing slot  32 . In order to enhance the engagement between the electronic device  10  and the standing slot  32 , two protruding blocks  33  are extrudingly disposed in the standing slot  32 , and two recessed portions (not shown), corresponding to the two protruding blocks  33  are disposed on the electronic device  10  respectively, so that the electronic device  10  does not detach from the standing slot  32  when the user touches or tabs the touch panel of the electronic device  10 . 
     Please refer to  FIG. 3 , which is a top view of the cover with angle adjustable standing slot of the first embodiment of the disclosure. Here, two driven members  40  are assembled in the receiving groove  21  and connected to the cradle  30 . In this embodiment, two driven members  40  is applied as an example and provided for disposing a large-size electronic device  10 , such as a tablet PC, therefore the two driven members  40  are respectively assembled in the receiving groove  21  for balance; for disposing a small-size electronic device  10 , such as a cell phone, one driven member  40  is applied to be assembled in the receiving groove  21 . 
     Similarly, the torque structure  50  is also assembled in the receiving groove  21  and connected to any one of the two driven members  40 . The torque structure  50  includes a torque gear  51  and a transmission gear  52 . The torque gear  51  engages with the transmission gear  52 , and the transmission gear  52  engages with the driven member  40 . As shown in  FIG. 3 , in order to save space and achieve the power transmission, one end of the driven member  40  which is near to the cradle  30  has a plurality of teeth  41 ; the transmission gear  52  is sectioned, one end thereof is engaged with the teeth  41  of the driven member  40 , and another end thereof is engaged with the torque gear  51 . Based on this, the linear movement of the driven member  40  is converted into a circular movement for driving the gears to rotate. 
     In this embodiment, since two driven members  40  are applied, besides the torque structure  50 , a gear set  70  is further assembled between the two driven members  40  and provided for transmitting the power from the driven member  40  distant from the torque structure  50  to the torque structure  50  to achieve a force balance. The gear set  70  includes a first gear  71  and a second gear  72 . The first gear  71  engages with the torque gear  51  of the torque structure  50 , and the second gear  72  engages with the first gear  71  and the driven member  40  distant from the torque structure  50 . Similarly, in order to save space and achieve the power transmission, one end of the driven member  40  has a plurality of teeth  41 , in which one end of the driven member  40  is near to the cradle  30  and the driven member  40  is distant from the torque structure  50 ; the second gear  72  is sectioned, one end thereof is engaged with the teeth  41  of the driven member  40  distant form the torque structure  50 , and another end thereof is engaged with the first gear  71 . 
     The two elastic structures  60  are assembled in the receiving groove  21  and respectively connected to the two driven members  40 . Each elastic structure  60  includes a rotating arm  61  and at least one elastic member  62 . The rotating arm  61  is respectively connected to one driven member  40  and at least one elastic member  62 . Similarly, for balance, two elastic structures  60  are applied in this embodiment; when the number of the driven member  40  is one, only one elastic structure  60  needs to be assembled in the receiving groove  21 . The rotating arm  61  includes a rotating shaft  611  and at least one engaging hook  612 . The elastic member  62  can be a spring but not limited thereto. One end of the elastic member  62  is fastened in the receiving groove  21 , and another end of the elastic member  62  is assembled with the engaging hook  612  of the rotating arm  61 . As shown in  FIG. 3 , the rotating arm  61  has a number of engaging hooks  612  assembled thereon, so that the number and the position of the elastic members  62  is adjusted based on the required elastic force computed according to the weight of the electronic device  10  and the contact force applied on the electronic device  10 . Moreover, although  FIG. 3  only shows the elastic structure  60  includes one elastic member  62 , the number and the types of the elastic members  62  is adjustable according to user requirements. 
     Next, please refer to  FIG. 4  and  FIG. 5 , which are respectively a cross-sectional view along line A-A shown in  FIG. 3  and a schematic view for showing the applied force of the cover with angle adjustable standing slot. When the user wants to adjust the angle between the electronic device  10  and the cover so as to apply a contact force F 1  on the electronic device  10  to rotate the electronic device  10  to the adjusted position, the electronic device  10  drives the cradle  30  to rotate using the pivoting shaft  31  as the rotating axis. Meanwhile, the cradle  30  pushes the two driven members  40  to move far from the keyboard  22 , and then each driven member  40  instantly drives the transmission gear  52  and the second gear  72  engaged therewith to rotate. Thereafter, the transmission gear  52  drives the torque gear  51  engaged therewith; the second gear  72  drives the first gear  71  engaged therewith, and the first gear  71  drives the torque gear  51 . Based on this, the transmission gear  52  and the second gear  72  drive the torque gear  51  to rotate, so that the torque gear  51  generates a torsion T. 
     Meanwhile, each driven member  40  drives the rotating arm  61  respectively, so that the rotating arm  61  rotates using the rotating shaft  611  as rotating axis so as to pull the elastic member  62  to generate an elastic force Fs. When the user stops forcing on electronic device  10 , the gravity F 2  of the electronic device  10  generates a moment M 1  to the cradle  30 ; simultaneously, the torsion T of the torque gear  51  and the elastic force Fs of the elastic member  62  resist against the driven member  40 , so that the driven member  40  pushes the cradle  30  to generate a moment M 2  opposite to the moment M 1 . When magnitude of the moment M 1  equals to that of the moment M 2  to achieve a balance condition, the cradle  30  is secured at the adjusted angle, thereby the electronic device  10  in the cradle  30  also being stayed at an appropriate viewing angle. 
     Based on the above mechanism, the moment generated from the weight of the electronic device  10  and the angle adjustment is converted into a planar force, which is then balanced by the torsional force from the rotating of the torque gear  51  and the elastic force from the stretching of the elastic member  62 , so that the angle between the cover and the electronic device  10  is adjustable and stoppable in any angle within an angle interval. Additionally, after the electronic device  10  is rotated and stayed at the adjusted position, the user can simply detach the electronic device  10  from the cradle  30  by pulling the electronic device  10  far from the cradle  30 ; at this moment, since the moment M 1  generated by the electronic device  10  is no longer applied to the cradle  30 , the force generated by the elastic member  62  overcomes the opposite force generated by the torque gear  51 , thereby the cradle  30  moving resiliently to the initial position. 
     To be provided for different electronic devices  10 , the moments M 1  of the electronic devices  10  with different sizes or weights are calculated, and then the number and the position of the torque gears  51  and the elastic members  62  are determined, so that the cover can be provided for different electronic devices  10 . For determining the number and the position of the torque gears  51  and the elastic members  62 , following three statuses and conditions need to be satisfied. 
     Status 1: The electronic device  10  does not fall down backwardly when the contact force F 1  is applied on the electronic device  10  or when the electronic device  10  is at rest. 
     Status 2: The electronic device  10  does not rebound forwardly after being adjusted to the adjusted position. 
     Status 3: The cradle  30  is moved resiliently after the electronic device  10  is detached from the cradle  30 . 
     The conditions of the three statuses are listed as below. 
     Status 1: the moment M 2  generated by the elastic member  62  and the torque gear  51  must be larger than or equal to the gravity F 2  of the electronic device  10  and the magnitude of the moment M 1  generated by the contact force F 1 . 
     Status 2: the magnitude of the summation of the moment generated by the maximum static friction force of the torque gear  51  and the moment generated by the gravity F 2  of the electronic device  10  must be larger than or equal to the moment generated by the elastic member  62 . 
     Status 3: the moment generated by the elastic member  62  must be larger than the moment generated by the maximum static friction force of the torque gear  51 . 
     The status 1 and the condition thereof prevents the electronic device  10  from falling down backwardly because of the contact force F 1  applied on the electronic device  10  upon the user operates the electronic device  10  by means of touch sensing; namely, when the user operates by means of touch sensing and applies a contact force on the electronic device  10 , the electronic device  10  drives the cradle  30  to rotate toward a direction opposite to the keyboard  22 , which is inconvenient for operating the electronic device  10  via means of touch sensing. Here, the forces generated from the torque gear  51  and the elastic member  62  are applied to balance the gravity F 2  of the electronic device  10  and the contact force F 1  applied on the electronic device  10 , so that the electronic device  10  will not fall down backwardly upon suffering a lighter force, such as the force for operating the electronic device  10  by means of touching the screen of the electronic device  10 . 
     The status 2 and the condition thereof ensure that after the electronic device  10  is adjusted to a required position, the electronic device  10  will stay at the adjusted position but not rebound to the initial position when force is no more applied to the electronic device  10 . As shown in  FIG. 5 , when the electronic device  10  is adjusted to the adjusted position and the contact force F 1  stops applying on the electronic device  10 , the force applied on the plane (the plane for placing the cover), is the component force F 21  of the gravity F 2  of the electronic device  10  on the plane. At this moment, the elastic force Fs generated by the elastic member  62  is provided for resisting against the component force F 21 ; if the elastic force Fs is too large, the elastic member  62  will drive the driven member  40 , so that the cradle  30  is pushed to the initial position, thereby resulting in the failure of maintaining the electronic device  10  at the adjusted position. In order to prevent the situation mentioned above, the magnitude of the summation of the moment generated by the maximum static friction force of the torque gear  51  and the moment generated by the gravity F 2  of the electronic device  10  must be larger than or equal to the moment generated by the elastic member  62 . 
     The status 3 and the condition thereof ensures that after the electronic device  10  is adjusted to the different adjusted positions, the user can detach the electronic device  10  from the cradle  30  directly and then the cradle  30  is moved resiliently, so that the user does not need to operate the cradle  30  additionally for moving the cradle resiliently; also, the user does not need to move the electronic device  10  to the initial position for detaching the electronic device  10 . Please refer again to  FIG. 5 , in which when the electronic device  10  is detached from the cradle  30 , the component force F 21  applied on the plane is disappeared and the elastic force Fs of the elastic member  62  and the moment generated by the maximum static friction force of the torque gear  51  are left; in a such situation, for recovering the cradle  30  to the initial position, the moment generated by the elastic member  62  must be larger than the moment generated by the maximum static friction force of the torque gear  51 . Consequently, the moment generated by the elastic member  62  drives the driven member  40  and pushes the cradle  30  to move to the initial position resiliently. 
     Please refer to  FIGS. 6-8 ,  FIG. 6  and  FIG. 7 , which are respectively an exploded view and a top view of a cover with angle adjustable standing slot of a second embodiment of the disclosure, and  FIG. 8  is a cross-sectional view along line B-B shown in  FIG. 7 . The cover with angle adjustable standing slot can be used to place an electronic device  10 . The cover includes a base  20 , a cradle  30 , a lid  80 , two driven members  40 , a torque structure  50  and two elastic structures  60 . In  FIG. 7 , in order to show the structures inside the cover, the lid  80  is not illustrated. 
     The structures of the second embodiment are approximately the same as that of the first embodiment, except that in this embodiment, the cover further includes the lid  80  covered on the receiving groove  21  and extended between the cradle  30  and the two driven members  40 . 
     As shown in the cross-sectional view illustrated in  FIG. 8 , one end of the lid  80  which is near to the cradle  30  is extended downwardly and disposed between the cradle  30  and the two driven members  40 . Based on this, the lid  80  is movable along with the movement of the cradle  30  and the two driven members  40  and covers the receiving groove  21  entirely during the movement of the lid  80 , so that the appearance of the cover is simple without any inner structures or components being exposed. 
     Additionally, please refer to  FIG. 7 , in which embodiment the torque gear is a monodirectional torque gear  53  and includes a ratchet structure  531  and a torque wheel structure  532 . That is, when the monodirectional torque gear  53  is rotated along one direction, the ratchet structure  531  drives the torque wheel structure  532  to generate torsional force; while when the monodirectional torque gear  53  is rotated along another direction, the ratchet structure  531  does not drive the torque wheel structure  532  and the torque wheel structure  532  does not generate torsional force. In this embodiment, when the monodirectional torque gear  53  is rotated counterclockwise, the ratchet structure  531  drives the torque wheel structure  532  to generate torsional force; while when the monodirectional torque gear  53  is rotated clockwise, the ratchet structure  531  does not drive the torque wheel structure  532  and the torque wheel structure  532  does not generate torsional force. 
     Based on this, when the electronic device  10  is detached from the cradle  30 , the moment generated by the elastic member  62  makes the elastic member pull the rotating arm without overcoming the moment generated by the maximum static friction force of the monodirectional torque gear  53  and drive the driven member  40  to push the cradle  30  to move resiliently. Accordingly, the selectivity of the number and the position of the elastic member  62 , or that of the stretching strength of the elastic member  62  are significantly increased. 
     Additionally, in this embodiment, the first gear  71  of the gear set  70  is also a torque gear. 
     Via the two-torque-gear configuration, a larger torsion can be provided, so that even an electronic device  10  with heavier weight can be applied to the cover with angle adjustable standing slot of the disclosure. 
     In this embodiment, when the electronic device  10  is placed in the cradle  30  with a contact force being applied to the electronic device  10  so as to drive the cradle  30  to rotate from the initial position to the adjusted position, the cradle  30  pushes the lid  80  to drive the two driven members  40 . And then, the two driven member  40  simultaneously drive the torque structures  50 , the gear set  70  and the two elastic structures  60 . At this moment, since the a force balance is formed among the torque structure  50 , the gear set  70 , the two elastic structures  60  and the electronic device  10 , the cradle  30  is secured at the adjusted position when the contact force is removed. Therefore, the angle between the cradle  30  and the electronic device  10  can be adjusted slightly rather than being fixed at a preset angle. 
     While the disclosure has been described by the way of example and in terms of the preferred embodiments, it is to be understood that the invention need not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures.