Abstract:
The present invention provides a structure improvement of spring hinge which mainly utilizes the tension adjustment stand, made of plastic composite material, to simplify the composition in order to achieve the purposes of reducing cost and the difficulties in assembling, yet to preserve the original intended functions, and an insertion portion extended from the end of the torque spring to insert a insertion hole formed at the tension adjustment stand to enhance the stability of the positioning of the torque spring and to abrade the torque produced by the torque spring to avoid broken the end of the torque spring.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to the hinges, and more particularly to a structure improvement of spring hinge, which is to place incision holes at the surface of the tension adjustment stands, and insert the insertion portions at two ends of the spring into these holes to increase the stability of the positioning of the torque spring, and to reduce the noise when operate, the difficulties in manufacturing and assembling, moreover, the tension adjustment stand made of plastic composite material because of the high durability, in order to avoid having the metal tubing part, and to simplify the composition such, and hence, reduce the difficulties in production and assembly. 
     FIG. 1 shows the prior art of a regular hinge used in large-scale heavy duty doors. This kind of the hinge is composed of a double-tube base plate  10 , a pair of torque springs  12  placed inner of the tubes  11 , and a pair of tension adjustment stands  13 ,  13 ′ placed at the ends of the tubes  11 . Place the ends  121  of the torque spring  12  inner the bottom of the trench, at the perimeter of the tension adjustment stand  13 , setup a plurality of adjustment holes  132  at equal distance in order to use a double-headed pin  14  to adjust the tension of the spring  12 . Also, there are a pair of turning flanges  20  that utilize the tips of the rods  22  to connect the tubes  11  at turned angle of the flanges  21 , and then, fasten the ends of the tubes  11  with a pair of threaded caps  23 . FIG. 2 shows an assembled spring hinge of FIG.  1 . This kind of the spring hinge utilizes the torque spring to store the tensile strength in order to accomplish the function of automatic door closing. However, this design included the following disadvantages: 
     1) The tension adjustment stand is made of metal, the manufacturing of such is difficult and expensive. 
     2) Furthermore, the stair-like hard surface is closely attached to the interior walls of the tubes  11 , after constant torque and turns, the diameters of the tubes will expand, which in turn, causes the hinge to disfigure. 
     3) Because the axle tips  22  are also made of metal, and the axles pass through the center of the tension adjustment base  13 . Furthermore, the a pair of tips of the torque springs  22  only rest on the groves of the tension adjustment bases  13 , that is, the a pair of ends of the torque springs circle around the stair-like surface of the tension adjustment bases. So when the torque spring  22  turns against the tension adjustment base, the movements are apparent and the contacts between the axle tips  22  and the interior walls create noises. If cracks appear at the trench  131 , it must be damaged by the torque of the spring  12 . 
     Based on the aforementioned disadvantages of the prior art, the applicant reinvented an improved spring hinge which had already granted patent by the U.S. PTO (Application Filed Number 08/590,631), please refer to FIGS. 3 and 4, which consists of a rectangular base plate  30  with a pair of tubes at the sides, as a unit, to form a pair of guiding tubes  31 , each of the guiding tube  31  contains a torque spring  32 , a ring cap  35  with a protruding lip  351  that matches with the diameter of the guiding tube  31 , and a first tension adjustment stand  33  made of plastic, which further contains a small metal tube  34  clips onto one end of the torque spring  32 . The first tension adjustment stand  33  inserts into a tip of the tube  31  and utilizes its cylindrical main body to rest on the ring cap  35 , a second tension adjustment stand  36 , made of plastic, directly inlays into the bottom of the guiding tube  31  where it also contains a small metal tube  34 ′ for clipping unto the other end of the torque spring  32 . A pair of flanges  40  using their turned angle protrusions  41  to hold the exteriors of the first and second tension adjustment stands  33  and  36 , and utilizing the tip of an axle rods  50  and a threaded cap  52  to connect to the second guiding tube  31 . A pair of adjustment pins  60  are inserted into an adjustment holes  336  at the perimeter of the first adjustment stand  33  for adjustment of the tension at the torque spring  32  and to press against the ends of the flanges  40 . 
     With the aforementioned improvement, the spring hinge will smoothly closes the door automatically without any noise or distortion. These improved portions are enough to ensure the structural stability, enhance durability, and increase actual functions. However, though the first and second adjustment stands  33  and  36  are made of enhanced plastic, still the inserted small metal tubes  34  and  34 ′ are necessary to sustain the opposite force exerted at the ends of the torque spring  32 . Otherwise, under the constant torque resistance from the torque spring  32 , the ends of the spring is likely to damage the first and second adjustment stands  33  and  36 . The small metal tubes  34  and  34 ′ are actually made of sheet metal bend into a tubular shape. When they are inserted into the first and second adjustment stands  33  and  36 , because of their elastic nature, they are closely fitted into the first and second adjustment stands  33  and  36 , hence they won&#39;t fall off the first and second adjustment stands  33  and  36 . The small metal tubes  34  and  34 ′ are difficult to manufacture, and the assembling of these tubes into the first and second adjustment stands  33  and  36  are quite difficult. Moreover, the end of the spring of the torque spring  32  winds into the side opening of the small metal tubes  34  and  34 ′, and positioned through these small metal tubes  34  and  34 ′. When the torque spring  32  turns, because of the tension is concentrate in the end of the spring  32 , the end of the spring  32  will fall off easily and cause a separation with the small metal tubes  34  and  34 ′ to cause any possible dangerous. The positioning of the torque spring  32  is not stable nor is it reliable, and the part of the stands  33  and  36  which touch with the end of the spring  32  will distract because of the torque spring  32  is in operate. 
     The present invention is arisen to militate and/or obviate the aforediscussed disadvantages in order to provide a new and novel structure hereinafter. 
     SUMMARY OF THE PRESENT INVENTION 
     The present invention has a main object to provide a structure improvement of spring hinge, which is to place incision holes at the ends of the tension adjustment stands, and insert the insertion portions at two ends of the spring into the holes to increase the stability of the positioining of the torque spring, and to reduce noises when operate, and to reduce the difficulties in manufacturing and assembling. 
     Another object of the present invention is to provide a structure improvement of spring hinge, which has a tension adjustment stand made of plastic composite material because of the high durability, in order to avoid having the metal tubing part, and to simplify the composition such, and hence, reduce the difficulties in production and assembly. 
    
    
     The present invention will become more fully understood by reference to the following detailed description thereof when read in conjunction with the attached drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view to show the prior art of the spring hinge, 
     FIG. 2 is an assembled partially sectional view of the FIG. 1, 
     FIG. 3 is an exploded perspective view to show the U.S. patent application Ser. No. 08/590,631. 
     FIG. 4 is an assembled partially sectional view of the FIG. 3, 
     FIG. 5 is an exploded perspective view to show the first preferred embodiment of the present invention, 
     FIG. 5A is a perspective view to show the large scale of the tension adjustment stand of FIG. 5, 
     FIG. 6 is an assembled partially sectional view to show the second preferred embodiment of the present invention, 
     FIG. 7 is an assembled partially sectional view to show the second preferred embodiment of the present invention, 
     FIG. 8 is a perspective view to show the third preferred embodiment of the present invention, and 
     FIG. 9 is an assembled partially sectional view to show the third preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Please refer to the drawings from FIGS. 5 and 6, the present invention of the improved structure of spring hinge, which comprises generally a rectangular base plate  70 , a pair of hollow cylindrical guiding tubes  71  connected to the base plate  70  on both sides, a pair of torque springs  72  placed into the guiding tubes  71 , a pair of first tension adjustment stands  73  positioned at the top of the guiding tubes  71 , a pair of second tension adjustment stands  74  pivoted at the bottom of the guiding tubes  71 , a pair of flanges  80  with their protruding plates  81  held unto the outside of the first and second tension adjustment stands  73  and  74 , a pair of axle rods  75  is penetrated into the guiding tubes  71  with the torque spring  72  and out of the guiding tubes  71 , then positioned the rods  75  with a pair of caps  751 . Finally, plug the ends of a pair of tension adjustment pins  76  into a pair of adjustment holes  736  formed at the outside perimeter of the first adjustment stands  73 , to adjust the torque spring  72  to an appropriate tension, whereas, the other end of the pins  736  is against at the top of the protruding angles of the flanges  80 . 
     The torque spring  72  has a section inwardly extended, and then axially extended outward to formed an insertion portion  721 . 
     The second tension adjustment stands  74  are made through plastic injection mold, as shown in FIG. 5A, which comprising a hollow lower section  741  whose outside diameter matches the inner diameter of that of the guiding tube  71 , a hollow middle portion  742  and a hollow upper portion  743 , an opening  744  located at periphery of the upper portion  743 , an insertion hole  745  located at the perimeter of the opening  744 . 
     The second tension adjustment stands  74  are also formed with plastic composite material, aside from the absence of the adjustment hole at the outside perimeter, the structure and shape of the second tension adjustment stands  74  are similar to the first tension adjustment stands  73 . 
     For assembly, the insertion portion  721  of the torque spring  72  winds into the opening  744  and continues to insert into the insertion hole  745 , so one side of the torque spring  72  can be fitted into the perimeter of the upper portion  743 . The upper portion  743  serves as a binding to one end of the torque spring  72 , at the same time, the middle portion  742  will distribute the torque exerted to the first and the second tension adjustment stands  73  and  74 , from the torque spring  72  through the opening  744  and the insertion hole  745  to avoid broken the end of the torque spring  72  and not to-cause abraded the periphery of the middle portion  743  by the end of the torque spring  72 . And through the insertion hole  745 , the torque spring  72  is stabilized. The reliability is enhanced; the difficulties in manufacturing and assembling are reduced. Furthermore, inner of the insertion hole  745  is penetrated with a metal tubing  738 , so one end of the torque spring  72  is placed inner the metal tubing  738  to increase the strength of the tension adjustment stand. 
     The function of the metal tubing  738  was increase strength of the insertion hole  745  not to broken when the torque against to the insertion hole  745 , but if the material of the tension adjustment stand strong enough to against the torque induced by the torque spring  72  and not to broken, the metal tubing  738  can be move from the insertion hole  745 . 
     Refer to FIG. 7, the second preferred embodiment of the present invention, a structure improvement of spring hinge, which applying in light duty door comprises a first and second leaf blades  91  and  93 , whereas, the periphery of the first leaf blade  91  extended with an arc shape protective cap  911  to formed a space to receive a torque spring  92  with a an axle rod  94  and a tension adjustment stand  95 , two ends of the first leaf blade  91  correspondingly bended into an certain angles to formed a first flange  912  and a second flange  913 , the length of the protective cap  911  is shorter than the distance between the first flange  912  and the second flange  913  to formed a first and second inserted gaps  914  and  915 , in order to insert a third and fourth flanges  931 ,  932  of the second leaf blade  93 , each of the first, second, third and fourth flanges  912 ,  913 ,  931  and  932  have a hole  97 , the axle rod  94  penetrated through the hole  97  of the first and second flange  912  and  913 , with the torque spring  92  and then through the third and fourth flanges  931  and  932  and out of the hole  97  of the first flange  912 . 
     The axle rod  94  penetrated the tension adjustment stand  95  between the torque spring  92  and the first flange  912 . The tension adjustment stand  95  modified from the previously described a first adjustment stand  73  of the first preferred embodiment of the present invention. The tension adjustment stand  95  is in cylindrical shape also made of lightweight and durable plastic composite material. The surface of the tension adjustment stand  95  horizontally contacted with the surface of the first flange  912 , the other surface of the tension adjustment stand  95  has an insertion hole  951 , and the inner of the insertion hole  951  is positioned with a metal tubing  952  then receive a insert portion  922  of the torque spring  92  into the metal tubing  952 , such is to increase the strength of the insertion hole  951  during the torque movement of the torque spring  92 . With the insert portion  922  of the torque spring  92  inserted into the insertion hole  951  while the other end of the spring torque  92  is extended with an arm  921 . The arm  921  extends from the periphery of the protective cap  911  and against to the perimeter of the second leaf blade  93  to position the torque spring  92 . A plurality of adjustment holes  952  with same internal diameter, located around the perimeter of the tension adjustment stand  95 , where a insertion pin  96  can be inserted into any adjustment hole  951  to push turn the tension adjustment stand  95  and to set the twist of the torque spring  92 . 
     Refer to FIGS. 8 and 9, there is a little different from the second preferred embodiments. The difference between the second and third preferred embodiments are two ends of the axle rod  101  placed with a pair of tension adjustment stands  105 , the tension adjustment stands  105  are similar to the tension adjustment stand  95  in FIG. 7, the different is on the same surface of a insertion hole  1051  of the tension adjustment stand  105  have a protective ring  1053 , the other different are a pair of insertion portion  1021  each axially outward from the ends of a torque spring  102 , the insertion hole  1051  receive a metal tubing  952 , for insertion portion  1021  of the torque spring  102  winds into the metal tubing  952 , to avoid overly concentrating the torque, so the tension adjustment stands  105  and  105 ′ of this embodiment, where the appropriate height of protective rings  1053  are receive the ends of the torque spring  102 . The protective rings  1053  are wrapped around the periphery of the torque spring  102  to cover the ends of the torque spring  102  and to position the torque spring  102 . So the insertion portion  1021  of the torque spring  102  is wrapped in the protective rings  1053  and  1053 ′ for holding purpose. So the torque spring  72  will preserves the direction of an axle rod  101 , and when the torque spring  102  is twisted, it won&#39;t shake nor will it touches the protective covers  111  or the axle rod  102  to create noise that further extend the life of the spring hinge. The protective ring  1053  cut with an opening  1054  and a plurality of insertion holes  1051  formed at peripheral of the stand  105 . The ends of the torque spring  102  placed into the internal space of the protective ring  1053  and the insertion portion  1021  penetrated into the insertion hole  1051  to stabilize the torque spring  102  and to distribute the torque through the insertion holes  1051 ; 
     Note that the specification relating to the above embodiments should be construed as exemplary rather than as limitative of the present invention, with many variations and modifications being readily attainable by a person of average skill in the art without departing from the spirit or scope thereof as defined by the appended claims and their legal equivalents.