Abstract:
A self-locking support arm is provided, comprising a hang arm and a linked device between a support seat and a connecting seat, which forms a set of four parallel connected rods. Therefore, when the support arm moving up and down, the connecting seat will maintain a fixed angle. A spring device is disposed between the hang arm and the linked device to provide tension of auto homing to the support arm. And, in a rotating joint formed by the linked device and the support seat, a ramp block and a ramp slider block is engaged, to provide an effect of self-locking, and better loading capacity.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a support arm. Especially, the present invention relates to a support arm, which is capable of automatically self-locking. The support arm not only has a function of being locked for positioning, but also has a benefit of supporting a heavier load.  
         [0003]     2. Description of the Related Art  
         [0004]     As the era and age of information technology comes, more and more processes or works must be done through the use of computer equipment, either in work or in live. However, computer equipments such as a mouse, a printer, a scanner, a display monitor, or a keyboard, takes a lot of space on the desk or table. Especially, when the desk is small, it is inconvenient to use or operate for a user. Notwithstanding the foregoing, when the computer equipments are installed, their height and angle are not suit for users of different sizes. As a result, injuries suffered on the job are open caused by using computer equipments, such as carpal tunnel syndrome and repetitive strain injury affected arms, hands eyes, muscles, and even bones. The computer equipments are often placed on support arms having flexible structure for reducing the injuries.  
         [0005]     A common used support arm is shown in  FIG. 1 . The conventional support arm consists of a chassis  10 , a front arm  17 , a hang arm  20 , a connecting rod  25 , and a spring  27 . The chassis  10  is a base frame having a shape like “U”. The front arm  17  is a frame having a shape like reversed “U”. The front arm  17  is provided at its top with a swing joint  171  and a connecting plate  173 . The hang arm  20  is a connecting rod having a cross-section like reversed “U”. The both lower ends of the side walls of the reversed “U” of the hang arm  20  are provided with a first axel bolt  11  so as to be assembled to the chassis  10 . The lower end of hang arm  20  forms a rotatable joint with the chassis  10  by the first axel bolt  11 . The both upper ends of the side walls of the reversed “U” of the hang arm  20  are provided with a second axel bolt  12 . The second axel bolt  12  is assembled with the front arm  17 . The upper end of the hang arm  20  forms a rotatable joint with the front arm  17  by the second axel bolt  12 . The both upper ends of the hang arm  20  are respectively provided with arc slots  21 . A third axel bolt  13  is disposed through the arc slots  21  onto the side walls of the front arm  17 , so as to fix the hang arm  20  to the front arm  17 . Connecting rod  25  is a rod having a cross section like “U”. The lower ends of both side walls of the connecting rod  25  are respectively provided with axel holes  251 . A fourth axel bolt  14  is disposed through the axel holes  251  onto the chassis  10 , to fix the connecting rod  25  to the chassis  10 . Therefore, the lower end of the connecting rod  25  forms a rotatable joint with the chassis  10  by the fourth axel bolt  14 . The both lower ends of the side walls of the connecting rod  25  are respectively provided with arc slots  253 . The first axel bolt  11  is disposed through the arc slots  253 . A third axel bolt  13  is disposed through the both upper ends of side walls of the connecting rod  25  onto the front arm  17 , so that the both upper ends of the side walls of the connecting rod  25  form a rotatable joint with the front arm  17 . The spring  27  is a coil type spring sleeved on the first axel bolt  11 . One end of the spring  27  is disposed against the connecting rod  25 , and the other end of the spring  27  is disposed against the fourth axel bolt  14 , so as to provide an appropriate upward reaction force.  
         [0006]     Please refer to  FIGS. 2A, 2B ,  3 A, and  3 B at the same time.  FIG. 2A  is a cross-sectional view of the conventional support arm at a first rotating angle.  FIG. 2B  is an enlarged cross-sectional view of the conventional support arm at the first rotating angle.  FIG. 3A  is a cross-sectional view of the conventional support arm at a second rotating angle.  FIG. 3B  is an enlarged cross-sectional view of the conventional support arm at the second rotating angle. As shown in the figures, a stop bolt  15  is disposed near the rear edges of the both side walls of the chassis  10 . Arc edges  255 , whose center is axel hole  251 , are formed at the rear edges of the lower ends of both side walls of the connecting rod  25 . The diameter of the axel hole  251  is larger than the diameter of a fourth axel bolt  14  disposed therein. The position of the stop bolt  15  is higher than the position of the fourth axel bolt  14 . Therefore, when the connecting rod  25  is not moving, it will droop due to the weight of a LCD display monitor (not shown). The distance from the axel hole  251  to the arc edge  255  is larger the distance from the center of the fourth axel bolt  14  to the arc edge  255 . The arc edges  255 , formed at the rear edges of the lower ends of both side walls of the connecting rod  25 , will engage with the stop bolt  15 , to form a support force acting on the hang arm  20 , in order to support the LCD display monitor (not shown) on the connecting plate  173  which is mounted on the front arm  17 . Furthermore, the diameter of the axel hole  251  is larger than the diameter of the fourth axel bolt  14  disposed the axel hole  251 , that is, there is a space formed between the axel bolt  251  and the fourth axel bolt  14 . When the connecting rod  25  is lifted up slightly, the arc edges  255 , formed at the rear edges of the lower ends of both side walls of the connecting rod  25 , will disengage from the stop bolt  15 . Then, the hang arm  20  and the connecting rod  25  can be moved smoothly, so as to adjust the position of the LCD display monitor.  
         [0007]     The conventional display monitor support arm has the benefit of simple components. However, when operating and manufacturing, it still has deficiencies as stated below:  
         [0008]     1. When support arm of the display monitor is adjusted to a required angle, it is positioned by the engagement of the stop bolt and the arc edges of the connecting rod to generate a friction force. After long time of use, the components will be worn which results in difficulty of positioning.  
         [0009]     2. The supporting force for positioning comes from the engagement between the stop bolt and the arc edges, therefore its loading capacity will be limited.  
         [0010]     3. The size and position of the axel hole of the connecting rod, the arc edges, and the fourth axel bolt must be precisely designed, manufactured, and assembled, in order to form the engagement. Therefore, it takes a lot of cost of manufacturing.  
       SUMMARY OF THE INVENTION  
       [0011]     According to the deficiencies of the conventional support arm stated above, there is a need of the present invention to provide a new design of support mechanism, which is capable of automatic locking, homing, and increasing loading capacity, and to maintain a fixed angle between the support seat and the ground when rotating.  
         [0012]     Thus there is a primary object of the present invention to provide a support arm for automatic locking, which forms a set of four parallel connected rod, that is capable of positioning by self locking, and to adjust the height of the support arm by user, by cooperating with a ramp block, a ramp slider block, and a spring device.  
         [0013]     Another object of the present invention is to provide an automatic locking support arm. The support arm contains a disk for reducing the needed rotating angle of the support arm, while the support arm is rotated to lock, and further enhancing the friction force to increase loading capacity of the support arm.  
         [0014]     Another object of the present invention is to provide an automatic locking support arm, which is capable of enlarging the range that the support arm can reach by using a connecting frame, to fulfill the need of operation of user.  
         [0015]     Another object of the present invention is to provide an automatic locking support arm, which is capable of maintaining an appropriate fixed angle of a connecting seat, when the support arm is rotating or after positioning.  
         [0016]     To achieve the above purpose, the present invention provides a support arm, which is able to be locked automatically and comprise a support chassis, a connecting seat, a hang arm, a spring device and a linked device. The support chassis includes a connecting cylinder, wherein at least one support wing is provided at one end of the connecting cylinder, and a first support axle hole and a second support axle hole are provided on the proper positions of the support wing. The connecting seat includes a connecting cylinder, wherein the connecting cylinder is provided with at least one connecting wing at one end of the connecting cylinder. A ramp block and a second connecting axle hole are provided on the proper positions of the connecting wing. The second connecting axle hole is able to penetrate through the connecting wing and the ramp block at the same time. A first connecting axle hole and a connecting arc slot are provided on the connecting wing. The hang arm includes a hallow cylinder, wherein a flange is provided on the inner surface of the hallow cylinder. At least one upper clamp disk and at least one lower clamp are provided separately at both ends of the hallow cylinder. The upper clamp disk is provided with a first upper clamp disk axle hole, a second clamp disk axle hole and an upper arc slot. The lower clamp disk is provided with a first lower clamp disk axle hole and a lower arc slot. A spring device includes at least one latch unit, one upper washer, one spring and one lower washer wherein both of the upper washer and the lower washer are provided with an axle hole. The linked device comprises at least one upper connecting rod, at least one lower connecting rod, at least one upper connecting block, at least one lower connecting block, at least one screw bolt and at least one ramp slider block. The upper connecting rod is provided with a first upper connecting rod hole and a second upper connecting rod hole at both ends. The lower connecting rod is provided with a first lower connecting rod hole and a second lower connecting rod hole at both ends. The upper connecting block is provided with an upper side slot and an upper connecting axle hole at one end and an upper connecting screw hole at another end. The lower connecting block is provided with a lower side slot and a lower connecting axle hole at one end and a lower connecting screw hole at another end. The ramp slider block is provided with a slider axle hole and a side slot, which is in accordance with the ramp block. Besides, an upper bolt is plugged through the upper connecting axle hole and the first upper connecting rod hole to connect the upper connecting block and the upper connecting rod. A lower bolt is plugged through the lower connecting axle hole and the first lower connecting rod hole to connect the lower connecting block and the lower connecting rod. Moreover, the screw bolt is able to penetrate through the lower washer, the spring and the upper washer. Then the screw bolt is screwed by the latch unit against the upper washer in order to be sleeved into the hallow cylinder of the hang arm. Therefore, the lower washer is lodged in the flange. The upper connecting block and the lower connecting block are locked into both ends of the screw bolt to form a linked device. The spring device is provided between the linked device and the hang arm, therefore the linked device, the spring device, and the hang arm form an arm set. The hang arm and the support seat are able to rotate relatively by plugging a first axle bolt through the first lower clamp disk axel hole and the first support axle hole. The hang arm and the connecting seat are able to rotate relatively by plugging a second axle bolt through the first upper clamp disk axel hole and the first connecting axle hole. The linked device and the hang arm are able to displace relatively when the linked device and the support seat rotate relatively by plugging a third axle bolt through the lower arc slot, the second support axle hole and the second lower connecting rod hole. The linked device and the hang arm are able to displace relatively when the linked device and the connecting seat rotate relatively by plugging a fourth axle bolt through the upper arc slot, the second connecting axle hole, the slider axle hole and the second upper connecting rod hole. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     The present invention will be more fully understood from the detailed description given hereinafter with reference to and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein:  
         [0018]      FIG. 1  is a perspective exploded diagram of a conventional support arm;  
         [0019]      FIG. 2A  is a cross-sectional view of the conventional support arm at a first rotating angle;  
         [0020]      FIG. 2B  is an enlarged cross-sectional view of the conventional support arm at the first rotating angle;  
         [0021]      FIG. 3A  is a cross-sectional view of the conventional support arm at a second rotating angle;  
         [0022]      FIG. 3B  is an enlarged cross-sectional view of the conventional support arm at the second rotating angle;  
         [0023]      FIG. 4A  is a perspective exploded diagram of a preferred embodiment of the present invention;  
         [0024]      FIG. 4B  is a side cross-sectional view of a preferred embodiment of the present invention;  
         [0025]      FIG. 5A  is a side cross-sectional view of a preferred embodiment of the present invention at a first rotating angle;  
         [0026]      FIG. 5B  is a side cross-sectional view of a preferred embodiment of the present invention at a second rotating angle;  
         [0027]      FIG. 6A  is an enlarged perspective exploded view of a linked device and a connecting seat of a preferred embodiment of the present invention;  
         [0028]      FIG. 6B  is an enlarged top view of the present invention shown in  FIG. 6A ;  
         [0029]      FIG. 7A  is a side view of a connecting frame of a preferred embodiment of the present invention;  
         [0030]      FIG. 7B  is a top view of the present invention shown in  FIG. 7A ;  
         [0031]      FIG. 8A  is a side view of a preferred embodiment of the present invention at a first rotating angle; and  
         [0032]      FIG. 8B  is a side view of the preferred embodiment of the present invention shown in  FIG. 8A  at a second rotating angle. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0033]     Please refer to  FIGS. 4A and 4B .  FIG. 4A  is a perspective exploded diagram of a preferred embodiment of the present invention.  FIG. 4B  is a side cross-sectional view of a preferred embodiment of the present invention.  
         [0034]     As shown in the figures, the present invention provides a support arm comprise a support chassis  30 , a support cylinder  31 , a connecting seat  40 , a hang arm  50 , a spring device  70  and a linked device  60 .  
         [0035]     The support chassis  30  includes a connecting cylinder  31 , wherein at least one support wing  33  is provided at one end of the connecting cylinder  31 , and a first support axle hole  331  and a second support axle hole  333  are provided on the proper positions of the support wing  33 .  
         [0036]     The connecting seat  40  includes a connecting cylinder  41 , wherein the connecting cylinder  41  is provided with at least one connecting wing  43  at one end of the connecting cylinder  41 . On the proper positions of the connecting wing  43 , a ramp block  48  and a second connecting axle hole  434  are provided as shown in  FIG. 6 . The second connecting axle hole  434  is able to penetrate through the connecting wing  436  and the ramp block  48  at the same time. Besides, a first connecting axle hole  432  and a connecting arc slot  435  are provided on the connecting wing  43 .  
         [0037]     The main structure of the hang arm  50  includes a hallow cylinder  51 , wherein a flange  517  is provided on the inner surface of the hallow cylinder  51 . At least one upper clamp disk  53  and at least one lower clamp  55  are provided separately at both ends of the hallow cylinder  51 . The upper clamp disk  53  is provided with a first upper clamp disk axle hole  532 , a second clamp disk axle hole  535  and an upper arc slot  534 . The lower clamp disk  55  is provided with a first lower clamp disk axle hole  551  and a lower arc slot  553 .  
         [0038]     A spring device  70  includes at least one latch unit  71 , one upper washer  73 , one spring  75  and one lower washer  77  wherein both of the upper washer  73  and the lower washer  77  are provided with an axle hole  79 .  
         [0039]     The linked device  60  comprises at least one upper connecting rod  65 , at least one lower connecting rod  67 , at least one upper connecting block  61 , at least one lower connecting block  63 , at least one screw bolt  62 , at least one disk  69  and at least one ramp slider block  68 .  
         [0040]     The upper connecting rod  65  is provided with a first upper connecting rod hole  651  and a second upper connecting rod hole  654  at both ends. The lower connecting rod  67  is provided with a first lower connecting rod hole  671  and a second lower connecting rod hole  673  at both ends. The upper connecting block  61  is provided with an upper side slot  613  and an upper connecting axle hole  611  at one end and an upper connecting screw hole  617  at another end. The lower connecting block  63  is provided with a lower side slot  633  and a lower connecting axle hole  631  at one end and a lower connecting screw hole  637  at another end. A first disk hole  692 , a second disk hole  695  and a disk arc slot  694  are provided on the proper positions of the disk  69 . The ramp slider block  68  is provided with a slider axle hole  684  and a side slot  681 , which is in accordance with the ramp block  48 .  
         [0041]     Besides, an upper bolt  86  is plugged through the upper connecting axle hole  611  and the first upper connecting rod hole  651  to connect the upper connecting block  61  and the upper connecting rod  65 . A lower bolt  87  is plugged through the lower connecting axle hole  631  and the first lower connecting rod hole  671  to connect the lower connecting block  63  and the lower connecting rod  67 . Moreover, the screw bolt  62  is able to penetrate through the lower washer  77 , the spring  75  and the upper washer  73 . Then the screw bolt  62  is screwed by the latch unit  71  against the upper washer  73  in order to be sleeved into the hallow cylinder  51  of the hang arm  50 . Therefore, the lower washer  77  is lodged in the flange  517 . The upper connecting screw hole  617  and the lower connecting screw hole  637  are locked into both ends of the screw bolt  62  to form a linked device  60 . The spring device  70  is provided between the linked device  60  and the hang arm  50 , therefore the linked device  60 , the spring device  70 , and the hang arm  50  assemble to an arm set  80 . Therefore, the assembly of the support arm structure is more flexible.  
         [0042]     The hang arm  50  and the support seat  30  are connected with each other by plugging a first axle bolt  81  through the first lower clamp disk axel hole  551  and the first support axle hole  331 . By the same way, the hang arm  50  and the connecting seat  40  are connected with each other by plugging a second axle bolt  82  through the first upper clamp disk axel hole  532  and the first connecting axle hole  432  and the first disk hole  692 . The linked device  60  and the hang arm  80  are connected with each other by plugging a third axle bolt  83  through the lower arc slot  553 , the second support axle hole  333  and the second lower connecting rod hole. The linked device  60  of the hang arm  80  are connected to the connecting seat  40  by plugging a fourth axle bolt  84  through the upper arc slot  534 , the second connecting axle hole  434 , the slider axle hole  684 , the second upper connecting rod hole  654  and the disk arc slot  694 . Therefore, a support arm with a structure of four parallel connected rods is formed. By penetrating a clamp bolt  85  through the second upper clamp disk axle hole  535  and the connecting arc slot  435 , the clamp force of the upper clamp disk  53  is improved.  
         [0043]     Furthermore, please refer to  FIGS. 5A and 5B .  FIG. 5A  is a side cross-sectional view of a preferred embodiment of the present invention at a first rotating angle, and  FIG. 5B  is a side cross-sectional view of the preferred embodiment of the present invention at a second rotating angle. As shown in figures, when the arm set  80  uses a the first axle bolt  81  as a revolving dot and the support seat  30  rotates relatively, the third axle bolt  83  of the support seat  30  will displace along the lower arc slot located on the hang arm  50 . And the third axle bolt  30  is connected with the lower connecting bolt  67  of the linked device  60  so that the hang arm  50  and the linked device  60  will displace relatively. In this way, the fourth axle bolt  84 , which is connected with the upper connecting bolt  65 , will displace along the upper arc slot  534 . Therefore, the connecting seat  40  will use the second axle bolt  82  as a revolving dot and rotates with the hang arm  50  relatively that keep a fixed angle between the connecting seat  40  and the ground during the rotating process of the hang arm. Furthermore, since the hang arm  50  and the linked device  60  displace relatively that could restore the plastic force of the spring  75  set up between the hang arm  50  and the linked device  60  and offer the support arm with automatic homing function.  
         [0044]     Please refer to  FIGS. 6A and 6B .  FIG. 6A  is an enlarged perspective exploded view of a linked device and a connecting seat of a preferred embodiment of the present invention.  FIG. 6B  is an enlarged top view of the present invention shown in  FIG. 6A . As shown in figures, the diameter of the second connecting axle hole  434  on the connecting seat  40  is larger than the diameter of the fourth axle bolt  84 . When the connecting seat  40  is pressed down by carrying all kinds of computer accessories such as monitor, printer, key board, mouse, scanner etc. computer, the connecting seat  40  will rotate by using the second axle bolt  82  as a revolving dot. Thus the slide block  48  fixed on the connecting seat  40  will displace along the slide slot  681  on the ramp slider block  68  to increase the axial distance between the slide block  48  and the ramp slider block  68 . The gaps between each component slipped on the fourth axle bolt increase accordingly. However, the distance formed between the upper clamp disk  53  is fixed, each component is tightly fitted, to result in a locking function of the support arm. Since the fourth axle bolt  84  penetrates the disk  69 , the angle of rotation for the support arm to turn to lock is reduced, and the friction force is increased, to raise the carrying ability of the support arm.  
         [0045]     Please refer to the  FIGS. 7A and 7B , which are side view and top view of another embodiment of the present invention. As shown in the figures, in this embodiment, a connecting frame  90  replaces the connecting seat  40  of the previous embodiment. The connecting frame  90  has a first side end  961 . The first side end  961  has a ramp block  48  at a predetermined position of itself. The ramp block  48  has a ramp surface and a second left axle hole  94 . The second left axle hole  94  penetrates the ramp block  48  and the connecting frame  90 . The connecting frame  90  further has a first left axle hole  92  and a left arc slot  95 . The function of the first left axle hole  92 , the left arc slot  95 , and the second left axle hole  94  is the same of the first connecting axle hole  434 , the second connecting axle hole  432 , and the connecting seat arc slot  435  of the connecting seat  40 . The connecting frame  90  has a second side end  971 . The second side end  971  has a first right axle hole  91  and a second right axle hole  93 . The function of the first right axle hole  91  and the second right axle hole  93  is the same of the first support axle hole  331  and the second support axle hole  333  of the support seat  30 .  
         [0046]     Finally, please refer to the  FIGS. 8A and 8B , which are side views of another embodiment of the present invention at a first rotating angle and a second rotating angle. As shown in the figures, the first side end  961  of the connecting frame  90  could be assembled with the above mentioned arm set  80  and support seat  30 , to form a fist support arm  96 . In the same way, the second side end  971  of the connecting frame  90  could be assembled with the above mentioned arm set  90  and connecting seat  40 , to form a second support arm  97 . Therefore, the effective range and distance of the support arm can be lengthened. More than two support arm can be used simultaneously to enlarge the assembly.  
         [0047]     Besides, the support cylinder  31  of the support seat  30  could be inserted into a fixed base  98 , so that the support seat  30  can rotate horizontally related to the fixed seat  98 . A platform  99  can be provided on the connecting cylinder  41  of the connecting seat  40 , so that the platform  99  could rotate horizontally related to the connecting seat  40 . Therefore, the range that the platform  99  can reach is enlarged, and the height of the platform  99  can be adjusted at will to fit the size of the user, so at to implement ergonomics in the support arm.  
         [0048]     While the invention has been described by way of examples and in terms of several preferred embodiments, it is to be understood that the invention need not be limited to the disclosed embodiment. 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.