Abstract:
A tensile switchable supporting frame is provided. The supporting frame with an adjustable tensile structure includes at least two elastic modules, which are composed of a plurality of tension springs to achieve the objective of multi-stage adjustment. According to the weight of the loaded device, the user is capable of selecting the suitable elastic module to appropriately activate the amount of tension springs. The proper tension also provides the user with a better operative experience.

Description:
This application claims priority to Taiwan Patent Application No. 103216391 filed on Sep. 16, 2014. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a tensile switchable supporting frame, and more particularly, to a supporting frame having a tensioning structure that allows for multi-stage adjustment of a loading force thereof. 
     2. Descriptions of the Related Art 
     Display products currently available are diversified with different specifications such as sizes and weights. Those supporting frames that support a display by means of fixed elastic force which cannot be adjusted, so that the application scope thereof is limited. In other words, when a display supported is replaced (e.g., because the user needs to replace it into a display of a greater size), the supporting frame might become unable to be continuously used. The user must purchase a new supporting frame that can match the new display. 
     Accordingly, an urgent need exists in the art to provide a supporting frame capable of switching between different tensile forces so as to be adapted to support electronic devices of different weights and to facilitate adjustment and operation by the user. 
     SUMMARY OF THE INVENTION 
     An objective of the present invention is to provide a tensile switchable supporting frame having a structural design that allows for multi-stage adjustment of a tensile force. The user can easily adjust the level of the tensile force and to select an appropriate loading capability to match the weight of different electronic devices or displays. 
     Another objective of the present invention is to provide a tensile switchable supporting frame in which elastic modules are composed of a plurality of tension springs respectively so that, according to a desired tensile force selected by the user, a corresponding amount of tension springs are activated and a better operational experience is provided to the user. 
     To achieve the aforesaid objectives, the present invention provides a tensile switchable supporting frame, which comprises a frame body, a pivoting shaft, a base and an adjustable tensile structure. The frame body is pivoted to the base via the pivoting shaft so that the frame body is capable of pivoting with respect to the base. 
     The adjustable tensile structure of the present invention comprises an accommodating base, a connecting string, a first elastic module, a second elastic module, a positioning plate and a first connecting element. The accommodating base is slidably disposed on the base. The two ends of the connecting string are engaged with the pivoting shaft and the accommodating base respectively. When the frame body pivots with respect to the base, the pivoting shaft pivots along with the frame body to drive the connecting string so as to drive the accommodating base. The first elastic module is disposed in the accommodating base, and comprises at least one first tension spring connected with the accommodating base and the base respectively. The second elastic module is disposed in the accommodating base, and comprises at least one second tension spring connected with the accommodating base and the first connecting element respectively. The positioning plate has a first groove, which comprises a first sliding region and a first limiting region that communicate with each other and extend in different directions. The first connecting element has a first column which penetrates through the first groove and selectively moves between the first sliding region and the first limiting region. In this way, the positioning plate is connected with the at least one second tension spring via the first connecting element. 
     When the positioning plate is located at a first position, the first column is located in the first sliding region, and when the frame body is folded towards the base, the connecting string is winded by the pivoting shaft to pull the accommodating base so that the first elastic module is tensioned. When the positioning plate is located at a second position, the first column is located in the first limiting region, and when the frame body is folded towards the base, the connecting string is winded by the pivoting shaft to pull the accommodating base so that both the first elastic module and the second elastic module are tensioned. 
     The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic perspective view of a tensile switchable supporting frame according to the present invention; 
         FIG. 1B  is a schematic exploded perspective view of the tensile switchable supporting frame according to the present invention; 
         FIG. 1C  is a schematic cross-sectional view taken along line A-A′ in  FIG. 1A ; 
         FIG. 1D  is a partial schematic bottom view of the tensile switchable supporting frame according to the present invention; 
         FIG. 2A  is a schematic perspective view of the tensile switchable supporting frame in a folded state according to the present invention; 
         FIG. 2B  is a schematic cross-sectional view taken along line B-B′ in  FIG. 2A ; 
         FIG. 2C  is a partial schematic perspective view of the tensile switchable supporting frame in a folded state according to the present invention; 
         FIG. 3A  is another schematic perspective view of the tensile switchable supporting frame according to the present invention; 
         FIG. 3B  is another partial bottom view of the tensile switchable supporting frame according to the present invention; 
         FIG. 3C  is another partial schematic perspective view of the tensile switchable supporting frame in a folded state according to the present invention; 
         FIG. 4A  is another schematic perspective view of the tensile switchable supporting frame according to the present invention; 
         FIG. 4B  is another partial bottom view of the tensile switchable supporting frame according to the present invention; and 
         FIG. 4C  is another partial schematic perspective view of the tensile switchable supporting frame in a folded state according to the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring firstly to  FIGS. 1A-1D , a tensile switchable supporting frame  1000  of the present invention comprises a frame body  1 , a pivoting shaft  2 , a base  3  and an adjustable tensile structure  4 . The base  3  is pivoted to the frame body  1  via the pivoting shaft  2  so that the frame body  1  is capable of pivoting with respect to the base  3 . The adjustable tensile structure  4  is disposed on the base  3  and can be connected with the pivoting shaft  2  so that the pivoting shaft  2  can drive the adjustable tensile structure  4  to move, as shown in  FIGS. 2A-2C . In order to clearly show the detailed operation mechanism of the adjustable tensile structure  4  when the tensile switchable supporting frame  1000  of the present invention is folded, the frame body  1  is omitted in  FIG. 2C . The detailed structure of the adjustable tensile structure  4  and its operational relations with other elements will be detailed hereinbelow. 
     The adjustable tensile structure  4  comprises an accommodating base  41 , three connecting strings  42 , a first elastic module  43 , a second elastic module  44 , a third elastic module  45 , a positioning plate  46 , a first connecting element  47  and two second connecting elements  48 . 
     The accommodating base  41  is slidably disposed on the base  3 , and two ends of each of the connecting strings  42  are engaged with the pivoting shaft  2  and the accommodating base  41  respectively. When the frame body  1  is folded towards the base  3  so that the frame body  1  pivots with respect to the base  3 , the pivoting shaft  2  pivots along with the frame body  1  to drive the connecting string  42  and the accommodating base  41  to move. Specifically, in the adjustable tensile structure  4  of this embodiment, the pivoting shaft  2  comprises three first engaging grooves  20 , the accommodating base  41  comprises three second engaging grooves  410 , and two ends of each of the connecting strings  42  are respectively provided with a protrusion  420   a . The pair of the protrusions  420   a  of each connecting strings  42  are correspondingly engaged into a corresponding one of the first engaging grooves  20  and into a corresponding one of the second engaging grooves  410  respectively. It should be noted that each of the connecting strings  42  winds around a part of the surface of the pivoting shaft  2 . Accordingly, when the pivoting shaft  2  pivots, each of the connecting strings  42  can be pulled to drive the accommodating base  41  to slide with respect to the base  3 . Additionally, the numbers of the connecting strings  42 , of the first engaging grooves  20  and of the second engaging grooves  410  can be correspondingly adjusted in coordination with each other as needed, and one set or more than four sets may be used. 
     Next, the structure of the first elastic module  43  and its corresponding connection relations with the accommodating base  41  and the base  3  will be described. The first elastic module  43  is disposed in the accommodating base  41 , and comprises two first tension springs  430 . The accommodating base  41  comprises a plurality of first protrusions  411 , and the base  3  correspondingly comprises a plurality of second protrusions  35  so that two ends of each of the first tension springs  430  are connected with a corresponding one of the first protrusions  411  and a corresponding one of the second protrusions  35  respectively. Furthermore, in this embodiment, each of the first protrusions  411  and each of the second protrusions  35  are formed respectively by locking a screw onto the accommodating base  41  and the base  3  (see  FIG. 1B ). Accordingly, the height of each of the first protrusions  411  and each of the second protrusions  35  can be adjusted according to the thickness of each of the ends of each of the tension springs. 
     Then, the connection relations between the second elastic module  44 , the accommodating base  41 , the positioning plate  46  and the first connecting element  47  will be described in further details. The second elastic module  44  comprises two second tension springs  440 ; the first connecting element  47  comprises two first extension portions  471  and a first column  470 ; and the positioning plate  46  comprises a first groove  460 . The first groove  460  has a first sliding region  460   a  and a first limiting region  460   b  that are intercommunicated with each other and extend in different directions. That is, the first sliding region  460   a  and the first limiting region  460   b  intersect with each other at an angle. In this embodiment, the first sliding region  460   a  is parallel to a tensioning direction D of each of the second tension springs  440 ; and the first sliding region  460   a  and the first limiting region  460   b  are perpendicular to each other, with the angle of 90°, to present a generally L-shaped form. The second elastic module  44  is disposed in the accommodating base  41 , and two ends of each of the second tension springs  440  are connected with the corresponding first protrusion  411  of the accommodating base  41  and the corresponding first extension portion  471  respectively. The first column  470  penetrates through the first groove  460 , and selectively moves between the first sliding region  460   a  and the first limiting region  460   b.    
     The connection relations between the third elastic module  45 , the accommodating base  41 , the positioning plate  46  and the second connecting elements  48  will be described in further details. The third elastic module  45  comprises two third tension springs  450 . Each of the second connecting elements  48  comprises a second extension portion  481  and a second column  480 . The positioning plate  46  further comprises two second grooves  461 . Each of the second grooves  461  has a second sliding region  461   a  and a second limiting region  461   b  that communicate with each other and extend in different directions. That is, the second sliding region  461   a  and the second limiting region  461   b  intersect with each other at an angle. In this embodiment, the second sliding region  461   a  and the second limiting region  461   b  are perpendicular to each other, with the angle of 90°, in the same manner as what described above in respect of the first sliding region  460   a  and the first limiting region  460   b . The third elastic module  45  is disposed in the accommodating base  41 , and two ends of each of the third elastic modules  45  are correspondingly connected with a corresponding one of the first protrusions  411  and a corresponding one of the second extension portions  481  so that the two ends of each of the third elastic modules  45  are connected with the accommodating base  41  and the second connecting element  48  respectively. Each of the second columns  480  penetrates through a corresponding one of the second grooves  461  and selectively moves between each of the second sliding regions  461   a  and a corresponding one of the second limiting regions  461   b . Accordingly, the third elastic module  45  is connected with the accommodating base  41  and the second connecting element  48  respectively, and the positioning plate  46  is connected with each of the third tension springs  450  via the second connecting element  48 . 
     Additionally, in other embodiments of the present invention, the numbers of the first tension springs  430 , the first protrusions  411  and the second protrusions  35 , the numbers of the second tension springs  440  and the first extension portions  471 , and the numbers of the third tension springs  450 , the second connecting elements  48  and the second grooves  461  can all be adjusted in coordination with each other as needed. 
     Please refer to  FIG. 1A ,  FIG. 1B  and  FIG. 1D . The connection relation between the positioning plate  46  and the base  3  will be described hereinafter. The base  3  comprises a through hole  30 , an adjusting knob  31 , a positioning column  32 , an upper surface  33  and a lower surface  34 . The positioning plate  46  comprises a first positioning hole  462   a , a second positioning hole  462   b  and a third positioning hole  462   c  that are intercommunicated with each other. The adjusting knob  31  is slidably disposed on a lower surface  34  of the base  3  by penetrating the through hole  30 , with a sliding direction thereof being substantially perpendicular to the tensioning direction D. The adjusting knob  31  has two fixing columns  31   a  that extend to be fixed to the positioning plate  46 . The positioning column  32  is fixedly disposed on an upper surface  33  of the base  3 . It is noted that the adjusting knob  31  is disposed on the lower surface  34  of the base  3  and accommodated in the through hole  30  without protruding from the lower surface  34  of the base  3  so as to avoid leaning of the supporting frame  1000  when being placed. Furthermore, the user will switch the adjusting knob  31  on the lower surface  34  to keep the hands thereof away from the upper surface  33  of the base  3 , thereby avoiding jamming of the hands due to an accidental folding of the frame body  1 . 
     Please refer to  FIG. 1A  and  FIG. 1B . When the adjusting knob  31  slides in the through hole  30 , the positioning plate  46  is driven to slide so that the positioning column  32  can slide between the first positioning hole  462   a , the second positioning hole  462   b  and the third positioning hole  462   c.    
     More specifically, referring to  FIG. 1A  and  FIG. 1B , the positioning column  32  is consisted of two elastic pieces  32   a  with a gap therebetween. The first positioning hole  462   a , the second positioning hole  462   b  and the third positioning hole  462   c  communicate with each other via a channel  462   d  respectively, and a width of the channel  462   d  is smaller than a diameter of each of the positioning holes. Therefore, when the adjusting knob  31  is slid to move the positioning column  32  to the channel  462   d , the elastic pieces  32   a  can be compressed, due to the gap therebetween, and become close to each other, so as to pass through the channel  462   d . And when the positioning column  32  moves to each of the positioning holes  462   a ,  462   b  and  462   c , the elastic pieces  32   a  restores to the original shape to keep the gap therebetween so that the positioning column  32  can stay at each of the positioning holes. 
     Finally, please refer to  FIG. 1A  and  FIG. 1B . The frame body  1  is further connected with a connecting base  5 , and the connecting base  5  may be used to be connected with a display module (not shown in the figures). 
     In this embodiment, the tensile switchable supporting frame  1000  allows for a three-stage adjustment. Operational relations among individual elements when the supporting frame  1000  is adjusted to a first stage, a second stage and a third stage will be described hereinafter. 
     Firstly, when the supporting frame  1000  is adjusted to the first stage and the adjusting knob  31  slides to a first location L 1  (see  FIG. 1D ), the positioning column  32  is engaged into the first positioning hole  462   a  so that the positioning plate  46  is positioned at a first position P 1 , as shown in  FIG. 1A . In this case, the first column  470  is positioned in the first sliding region  460   a , and the first column  470  is located at a first end  4601  of the first sliding region  460   a , as shown in  FIG. 1C . At this point, the connecting base  5  has the furthest distance from the base  3  (i.e., the display module is located at the highest position). When the user needs to adjust the height of the display module by moving the connecting base  5  downwards towards the base  3 , the frame body  1  and the pivoting shaft  2  are driven to pivot to get close to the base  3  at the same time. 
     According to the above descriptions and as shown in  FIG. 2C , when the frame body  1  is folded towards the base  3 , the connecting string  42  is winded by the pivoting shaft  2  to pull the accommodating base  41  so to tension the first elastic module  43 . Meanwhile, the first connecting element  47  is driven by the accommodating base  41  via the second elastic module  44  to slide the first column  470  from the first end  4601  towards a second end  4602  of the first sliding region  460   a . That is, because the first sliding region  460   a  extends in a direction parallel to a tensioning direction D of the second tension spring  440 , the first column  470  can slide in the first sliding region  460   a ; and in a case that one end of the second tension spring  440  is not fixed, each of the second tension springs  440  is not tensioned and only the first tension spring  430  of the first elastic module  43  is tensioned. In other words, only the first tension spring  430  provides a tensile force to achieve a supporting effect during the folding process. 
     Referring to  FIG. 3A  and  FIG. 3B , when the supporting frame  1000  is adjusted to the second stage and the adjusting knob  31  slides to a second location L 2 , the positioning plate  46  is slid with respect to the base  3  so that the positioning column  32  engages into the second positioning hole  462   b . The positioning plate  46  is positioned at a second position P 2 , and the first column  470  is positioned in the first limiting region  460   b.    
     Referring to  FIG. 3C , when the frame body  1  is folded towards the base  3 , the connecting string  42  is winded by the pivoting shaft  2  to pull the accommodating base  41 . Because the first limiting region  460   b  is perpendicular to the tensioning direction D, the first column  470  positioned in the first limiting region  460   b  is limited from sliding. Thus, each of the second tension springs  440  is capable of being tensioned. Therefore, in the folding process, the first tension springs  430  and the second tension springs  440  are tensioned at the same time, and as a result, a heavier display module can be supported now. 
     It should be particularly noted that, in the aforesaid first stage or second stage (i.e., when the adjusting knob  31  is positioned at one of the first location L 1  or the second location L 2 ), none of the third tension springs  450  of the third elastic module  45  will be tensioned during the folding process. This is because that a second width W 2  of the second sliding region  461   a  is greater than a first width W 1  of the first sliding region  460   a  (see  FIG. 1B ). So, even if the positioning plate  46  is adjusted from the first position P 1  to the second position P 2  (i.e., moves towards the top left corner in  FIG. 1B ), the second column  480  will still stay in the second sliding region  461   a . Therefore, the third tension spring  450  will not be tensioned. 
     Referring to  FIG. 4B , when the supporting frame  1000  is adjusted to the third stage (i.e., when the adjusting knob  31  slides to a third location L 3 ), the positioning plate  46  is driven to slide with respect to the base  3  so that the positioning column  32  engages into the third positioning hole  462   c  and the positioning plate  46  is positioned at the third position P 3 , as shown in  FIG. 4A . In this case, the second column  480  moves into the second limiting region  461   b.    
     Referring to  FIG. 4C , when the frame body  1  is folded towards the base  3 , the connecting string  42  is winded by the pivoting shaft  2  to pull the accommodating base  41 . Because the first limiting region  460   b  and the second limiting region  461   b  are both perpendicular to the tensioning direction D, the first column  470  and the second column  480  are limited from sliding. Therefore, the first tension spring  430 , the second tension spring  440  and the third tension spring  450  are tensioned at the same time. 
     Accordingly, by positioning the positioning plate  26  at the first position P 1 , the second position P 2  or the third position P 3 , the supporting frame  1000  of this embodiment can be adjusted to the first stage, the second stage or the third stage to support display modules of different weights respectively, e.g., a 20-inch display module of 7 kg, a 21-inch display module of 9.5 kg and a 23-inch display module of 12 kg. However, this is not intended to limit the tensile forces of the first elastic module  43 , the second elastic module  44  and the third elastic module  45 , and the numbers of the first tension springs  430 , the second tension springs  440  and the third tension springs  450  and the tensile strengths thereof can be adjusted as needed. 
     Referring to  FIG. 1A  and  FIG. 1B , in order to increase the loading force of the supporting frame  1000 , the tensile switchable supporting frame  1000  of this embodiment further comprises a torsional spring assembly  6  disposed on the base  3  and joined to the pivoting shaft  2 . The torsional spring assembly  6  comprises two torsional spring units  61  connectively sleeve on two sides of the pivoting shaft  2  respectively, to support the weight of display module together. However, in other embodiments of the present invention, the torsional spring assembly  6  may be omitted as needed. 
     According to the above descriptions, by sliding the adjusting knob, the positioning plate can slide to different positions and the number of the elastic modules that are tensioned can be adjusted in multiple stages so that the user can correspondingly adjust the loading force of the supporting frame according to the weight of the purchased display module. Furthermore, even if the user replaces the original display module with display modules of different weights, it is only necessary to make a corresponding adjustment by means of the adjusting knob without having to buy a suitable new supporting frame. Additionally, the supporting frame of the present invention can provide the user with a better operational experience. 
     The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended.