Abstract:
A hinge positioning structure is used to couple a body and a leg of a stand. The hinge positioning structure has a joint groove formed in the body, a stopper attached at the bottom of the joint groove having an elastic body with a spring strip, and a hinge formed in the leg positioned in the joint groove. The leg has two sides, each side having a pivot positioned according to a corresponding pivot hole in the joint groove for rotatable insertion into the corresponding pivot hole of the joint groove, and two flanges, each flange parallel to the spring strip and radially protruding a first height sufficient to contact with the spring strip for generating a resistance.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to folding stands, and more particularly, to a folding stand that uses a hinge with a positioning groove to press against a spring strip. 
   2. Description of the Prior Art 
   A general foldable stand comprises a body and legs. When the legs are unfolded, the body stands with the legs. When the legs are folded, the stand becomes portable. Please refer to  FIG. 1 .  FIG. 1  is a diagram illustrating a foldable stand of the prior art. As shown in  FIG. 1 , the foldable stand comprises a body  1  and a leg  3 . The body  1  comprises a joint groove  2 , a spring  5 , a bolt  6 , and a container  9 . The leg  3  comprises a support  8  and a hinge  4 . The hinge  4  comprises a set of positioning holes  7 . 
   The joint groove  2  is disposed in the body  1  for accommodating the hinge  4 . The spring  5  is disposed in the joint groove  2  to push the bolt  6 . Thus, the bolt  6  is pushed into one hole of the set of positioning holes  7  when that hole moves to the appropriate position, and the leg  3  is fixed. The set of positioning holes  7  comprises a first hole and a second hole. 
   When the leg  3  is unfolded, the support  8  is moved away from the container  9  of the body  1 . The support  8  rotates around the hinge  4  until the bolt  6  is pushed into the first hole of the set of positioning holes  7 . Then the leg  3  is fixed at an unfolded position and a predetermined angle is formed between the leg  3  and the body  1 . Thus, the foldable stand stands. 
   When the leg  3  is folded, the support  8  is moved toward the container  9  of the body  1 . The support  8  rotates around the hinge  4  until the bolt  6  is pushed into the second hole of the set of positioning holes  7 . Then the leg  3  is fixed at a folded position and the support  8  is contained in the container  9 . 
   When a user folds the stand, the user has to apply a sufficient force to the support  8  to provide a torque that can enable the bolt  6  inserted into the first hole to slide out and to insert into the second hole. The same condition exists when the user unfolds the stand. Therefore, in design, the spring  5  is not too strong and the set of positioning holes  7  is not too deep. Utilizing such a design allows the user to apply only a little force to fold or unfold the stand, and prevents the bolt  6  from jamming in the positioning holes  7 . 
   However, the design of the stand of the prior art is unable to provide a strong hold for the stand. The stand can fold and unfold too easily. That means the stand is not firm. When the stand is unfolded to carry a heavy object, the leg  3  may be folded by the pressure of the heavy object, causing the object to fall. Thus, the prior art cannot provide a strong stand for the user. 
   SUMMARY OF THE INVENTION 
   According to the present invention, a hinge positioning structure used to couple a body and a leg of a stand comprises a joint groove formed in the body comprising two sides, each side of the joint groove comprising a pivot hole, a stopper attached at the bottom of the joint groove having an elastic body comprising a spring strip, and a hinge formed in the leg positioned in the joint groove comprising two sides, each side having a pivot positioned according to the corresponding pivot hole for rotatable insertion into the corresponding pivot hole of the joint groove, and two flanges, each flange parallel to the spring strip and radially protruding a first height sufficient to contact with the spring strip for generating a resistance. 
   These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a diagram of a stand according to the prior art. 
       FIG. 2  is a diagram of a hinge positioning structure according to the present invention. 
       FIG. 3  is a diagram of compressing a spring strip in the hinge positioning structure of  FIG. 2 . 
       FIG. 4  is a diagram of unfolding a leg of the hinge positioning structure of  FIG. 2 . 
       FIG. 5  is a diagram of a second embodiment of the hinge positioning structure according to the present invention. 
   

   DETAILED DESCRIPTION 
   Please refer to  FIG. 2 .  FIG. 2  is a diagram illustrating a stand using a hinge positioning structure  10  of the present invention. The stand comprises a body  11 , a leg  12 , and a hinge positioning structure  10 . The hinge positioning structure  10  is used to couple the body  11  and the leg  12  for enabling the leg  12  to rotate relative to the body  11 . Thus the stand is able to fold and unfold. 
   Please continue referring to  FIG. 2 . The body  11  of the present invention comprises a joint groove  13 , a stopper  15 , and a container  19 . The joint groove  13  comprises two pivot holes  14  at both sides of the joint groove  13 . The stopper  15  is disposed at the bottom of the joint groove  13  and is made of rubber or another elastic material. The stopper  15  comprises a baseboard  151  and a spring strip  152 . The baseboard  151  comprises two thick sides and a protruding center to form a bridge-shaped board. Each of the two thick sides has a screw hole  153 . The spring strip  152  is disposed on the protruding center and the position of the spring strip  152  slightly deviates from a central line of the protruding center. The shape of the spring strip  152  is a rectangular bar. The stopper  15  is attached below the joint groove  13  by screwing screws  16  into the screw hole  153  of each of the two sides of the baseboard  151 . Thus, the protruding center is positioned at the bottom of the joint groove  13  so that the spring strip  152  is placed across the bottom of the joint groove  13  and protrudes to an appropriate height. Additionally, the stopper  15  is elastic to allow the protruding center to move downward within a space as shown by an arrow in  FIG. 2 . 
   Please continue referring to  FIG. 2 . The leg  12  of the present invention comprises a support  17  and a hinge  18 . The support  17  is basically board-shaped. The hinge  18  is basically cylinder-shaped to match the joint groove  13 . The hinge  18  comprises two pivots  181 , two flanges  182 , two positioning grooves  183 , and a spacious groove  184 . The two pivots  181  are disposed at both sides of the hinge  18  for insertion into the pivot holes  14  of the body  11 . The sizes of the pivots  181  match those of the pivot holes  14 . The flanges  182  are cuboids and protrude from the hinge  18  to a predetermined height to contact with the spring strip  152  when the hinge  18  rotates over a predetermined angle. One of the flanges  182  is disposed along the axis of the hinge  18  and positioned to contact with the spring strip  152  when the stand of the present invention is folded. The other one of the flanges  182  is disposed along the axis of the hinge  18  and positioned to contact with the spring strip  152  when the stand of the present invention is unfolded. Each of the positioning grooves  183  is disposed at the outer side of each of the flanges  182  and parallel to the flanges  182 . The spacious groove  184  is disposed between the inner sides of the flanges  182 . 
   Please continue referring to  FIG. 2 . The following describes assembly of the hinge positioning structure  10  of the present invention. The screws  16  are screwed through the screw holes  153  onto the body  11  for fixing the stopper  15  below the joint groove  13  and positioning the spring strip  152  across the bottom of the joint groove  13 . Thus, the spring strip  152  protrudes a predetermined height from the bottom of the joint groove  13 . The hinge  18  is installed with the pivots  181  embedded in the pivot holes  14  of the joint groove  13 . After embedding in the pivot holes  14 , the pivots  181  are still able to rotate. During the rotation of the hinge  18 , the spacious groove  184  provides a predetermined angle to the hinge  18  to revolve without being blocked by the spring strip  152  because the spring strip  152  does not contact with the spacious groove  184 . However, the positioning grooves  183  are narrow enough to hold the spring strip  152  such that the leg  12  cannot rotate. 
   Please refer to  FIG. 3 . When the hinge positioning structure  10  is folded, the support  17  of the leg  12  is situated in the container  19  of the body  11 , the spring strip  152  of the stopper  15  is stuck in the positioning groove  183 , the spring strip  152  is restricted by the positioning groove  183 , and the flange  182  obstructs the spring strip  152  to hold the support  17  to the body  11  for easier transport. When a force is applied to rotate the support  17 , the flange  182  compresses the spring strip  152 , such that the protruding center of the stopper  15  underneath the spring strip  152  will flex downward (as shown by the dotted lines in  FIG. 3 ), such that the flange  182  can pass over the spring strip  152 . When the spacious groove  184  is over the spring strip  152 , the support  17  can rotate freely. 
   Please refer to  FIG. 4 . When the support  17  rotates such that the flange  182  contacts the spring strip  152 , a force is applied to rotate the support  17  again, and the flange compresses the spring strip  152 , causing the protruding center of the stopper  15  underneath the spring strip  152  to flex downward, such that the flange  182  can pass over the spring strip  152 . The spring strip  152  enters, and is restricted by, the positioning groove  183 , such that the support  17  cannot rotate further, and holding the leg  12  in an unfolded state. Because the spring strip  152  is slightly offset from the center of the stopper, i.e. is not on the axis of the joint groove  13 , the contact area of the length of the flange  182  and the length of the spring strip  152  can form an elongated surface which, aside from providing a stronger support to support a heavier weight in the body  11 , can also prevent wear caused by the point support stress of the prior art. If the leg  12  is positioned on a plane, the body  11  can stand. 
   When the leg  12  is folded, an opposite sequence to that described above for unfolding occurs. As the support  17  is pressed toward the body  11 , the flange  182  compresses the spring strip  182 , such that the center portion of the stopper  15  flexes downward to allow the flange  182  to pass. As the support  17  continues toward the body  11 , the spring strip  182  passes freely through the spacious groove  184  until the flange  182  is contacted. The flange  182  compresses the spring strip  182 , such that the center portion of the stopper  15  flexes downward to allow the flange  182  to pass. The spring strip  182  enters, and is restricted by, the positioning groove  183 , and the support  17  is held firmly against the body  11  in the container  19 , which completes folding of the leg  12 . 
   Although the present invention described above in terms of the preferred embodiment uses a sharp-cornered, rectangular shape for the flanges  182  and the spring strip  152  as an example, the flanges  182  and the spring strip  152  could also have a rounded shape as shown in  FIG. 5 . The rounded shape reduces rubbing between the flanges  182  and the spring strip  152 , while still achieving the effect and goal of the present invention, and also falls within the art of the present invention. 
   Thus, through the positioning of the stopper  15  and the positioning grooves  183 , the stopper  15  of the present invention hinge positioning structure  10  can restrict rotation of the leg  12 , providing a strong support, such that the stable positioning of the leg  12  can hold a heavier body. Simultaneously, the flange  182  and the spring strip  152  form a rectangular contact surface which distributes weight from the body, which reduces stress to the flange  182  and the spring strip  152 , thereby reducing wear between the components and increasing the life of the product. The hinge positioning structure  10  also can use a smaller leg  12  relative to the weight supported compared to the prior art, while providing a more reliable stand. Finally, the present invention forms the flanges  182  and the positioning grooves  183  directly on the hinge  18 , which not only reduces the number and cost of components, but also only requires using screws to fix the stopper  15  to the bottom of the joint groove  13  to complete assembly, which reduces assembly steps and time, thereby also saving cost of manufacturing. 
   Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.