Abstract:
A breaking structure of measuring tape, including a housing, a tape rule contained in the housing and a braking mechanism, characterized in that: a push button is formed onto the housing, by pushing the push button into the housing to keep it at a lower position; a braking plate of the braking mechanism would effectively suspend the movement of the tape rule, and after that, if the push button is pushed downward again, the braking mechanism would push the push button upward and return to its higher position, and the braking plate of the braking mechanism would separate the tape rule and the movement of the tape rule would not be suspended.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a braking structure of measuring tape, especially to a braking mechanism by which the movement of the rule would be effectively suspended, and the braking function of measuring tape is easily to be withdrawn by simply pushing a control button. 
   2. Description of the Prior Art 
   As shown in  FIG. 1A , the conventional measuring tape rule has a pushing key  101  above the housing  100 , the pushing key  101  is connected with a pressing leg  102  which is put inside the housing  100 . When the pushing key  101  is pushed downward by the user, the pressing  102  would slide downward and its lower end would press the upper surface of tape rule  103 ; then the movement of tape rule  103  is suspended (as shown in  FIG. 1B. ) 
   In using the above shown structure, since the movement of tape rule  103  is suspended when the pushing key  101  is pushed downward and the lower end of said pressing leg is pressed against the tipper surface of the tape rule  103 , when the pushing force is withdrawn, the tape rule would be rewound back into the housing immediately. It is then inconvenient for people to use. 
     FIG. 1C  shows another prior art of measuring tape invented by the inventor. It is characterized in that, a pushing key  201  can be installed onto an upper corner of the housing, said pushing key  201  can be rotated with a shaft  202  through the center of the lower end of said pushing key  201 . Such that when one end of pushing key  201  is pushed downward, the pressing element  203  installed beneath the pushing key  201  would be pushed downward to press the tape rule  204 , then if different end of the pushing key  201  is pressed, then the pressing force against tape rule is removed. 
   In using the measuring tape as shown in  FIG. 1C , the movement of tape rule can be easily controlled. However, it is still necessary to install a pushing key onto the housing, then the beauty of a whole body and the comfort of holding the measuring tape are greatly reduced. 
   Furthermore, in order to suspend the movement of the tape rule, a pushing force which would overcome the force to rewind the tape rule should be performed. It is a hard work to people&#39;s thumb. Therefore, the conventional measuring tapes are not convenient for people&#39;s uses. 
   In addition, since the pushing key has to have the function of pushing the tape stopping element, the measuring tape together with its tape stopping element then has to occupy a relative volume to endure the stopping force performed onto the pushing key. It is then easy to cause injury to people. 
   In order to improve the aforementioned defects, the inventor of present invention has made a great effort and has made many novel designs. 
   SUMMARY OF THE INVENTION 
   Accordingly, the object of the present invention is to provide a braking structure of a measuring tape which is actuated by a push button set in an opening formed on the housing of the measuring tape and a braking mechanism installed inside the housing. When the push button is pushed to move up and down, the braking mechanism would be moved so as to stop or release the tape rule. Thus, the rule may conveniently and effectively be controlled. 
   A further object of the present invention is in that the push button can be easily pushed downward by a light force rather than by heavily pushing the conventional pushing key. It is then much easier and convenient to people. 
   The present invention will be better understood and its numerous objects and advantages will become apparent to those skilled in the art by referencing to the following drawings in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  is a cross-sectional view of a prior measuring tape. 
       FIG. 1B  is a cross-sectional view of a prior measuring tape of  FIG. 1A  in using. 
       FIG. 1C  is a cross-sectional view of another prior measuring tape. 
       FIG. 1D  is a cross-sectional view of another prior measuring tape of  FIG. 1C  in using. 
       FIG. 2  is a perspective view of the present invention. 
       FIG. 3  is an exploded view showing the measuring tape according to the present invention. 
       FIG. 4  is a plane view showing the braking mechanism of present invention. 
       FIG. 5  is an enlarged plane view showing the heart-shaped furrow of present invention. 
       FIG. 6  is a cross-sectional view seeing from A—A line of  FIG. 5  showing the heart-shaped furrow of present invention. 
       FIG. 7  is a cross-sectional view seeing from B—B line of  FIG. 5  showing the heart-shaped furrow of present invention. 
       FIG. 8  is a side view showing the action of the braking mechanism of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1A  to  1 D show the examples of conventional measuring tape; their functions and disadvantages are described as above; it is not repeated herewith. 
   As shown in  FIG. 2 , the outer body of the measuring tape of present invention is composed by a housing  1  and a control button  2  is installed in an opening formed at the front upper portion of the housing  1 , the housing  1  is constructed by a left housing  14  and a right housing  15  to screw together, and the housing is covered by a left housing sleeve  11  and a right housing sleeve  12 ; an opening  13  to be the exit of tape rule is also formed at the lower end of front side of the housing  11 . 
   As shown in  FIG. 3 , inside the housing  1 , there is a tape rule  3  and a braking mechanism  4  is installed into a front space inside the housing  1 . Said tape rule  3  is clamped by said left housing  14  and right housing  15 , and the free end of tape rule  3  can slide through said tape rule exit  13 ; at the front lower portion on the left housing  14  and the right housing  15  near said tape rule exit  13 , a semi-braking furrow  16  is respectively formed. Said semi-braking furrow  16  has a plurality of grooves  161 , such that after said semi-braking furrow  16  is formed by combing the housings  14  &amp;  15 , the upper surface of said semi-braking furrow  16  is formed as a concave surface to meet the bottom surface of the tape rule. In addition, each of the upper corner of said housings  14  &amp;  15  is formed respectively with a semi-arc opening  141  &amp;  151 , such that after said housings  14  &amp;  15  is combined, an opening is formed by the two semi-arc openings  141  &amp;  151  for said control button  2  to pass through. Said control button  2  formed in an irregular shape, its upper-end is a pressing portion  21 , and its lower end is communicated to a braking mechanism  4 . 
   Please refer to FIG.  3  and  FIG. 4 , the braking mechanism  4  is composed of a stem  5 , a spring  6 , a pressing seat  7  and a braking plate  8 , wherein the stem  5  is a long strip body, an upper flange  51 , a lower flange  52 , a vertical long-shaped furrow  53  is formed on the body of the stem  5 , and under the long-shaped furrow  53 , a heart-shaped furrow  54  is formed. The upper flange  51  is used for supporting control button  2 , the lower flange  52  is used for the spring  6  to put oil, the lower section of the stem  5  passes the vertical via the hole formed in the pressure seat  7  and then touches the braking plate  8 . Said pressure seat  7  is positioned by two flanges  71  be extended into a pair of extended into a pair of mounting furrows  17  formed inside the housing. On the pressure seat  7 , there are also an upper hole  72  and a lower hole  73 . Between the said long-shaped furrow  53  and said heart-shaped furrow  54 , there is a “” shaped hook  55  with its two free ends respectively inserted into said long-shaped furrow  53  and said heart-shaped furrow  54 . The upper section of hook  55  is held by the spring  6  mounted onto the stein  5 , and the upper end of the spring  6  is stopped by said lower flange  52  formed on the stem  5 . While the lower end of the spring  6  is stopped by the top surface of the pressure seat  7 , the two free ends of said “” shaped hook are also respectively inserted into the upper hole  72  and the lower hole  73  formed on the pressure seat  7 . 
   The braking plate  8  contains a plurality of segments. Its upper edge extrudes a pair of ears  81  to be inserted into a pair of inserting holes  18  formed inside the housing  14  &amp;  15 . Such that the braking plate  8  can rotate with said ears  81  as rotation shaft. The central portion of said braking plate  8  is a slope plate  82 . After combination, the lower end of said braking plate  8  is positioned above the tape rule, and near the upper front end of said two semi-braking furrows  16 . 
   As shown in  FIGS. 5 ,  6  &amp;  7 , said heart-shaped furrow  54  is formed as a guiding path, its lower stop point  541  and upper stop point  542  contain the deepest grooves, in the clockwise groove  5 A and counter-clock groove  5 B formed between the lower stop point  541  and upper stop  542 . There are a plurality of ribs  543 ,  544 ,  545 , such that the lower end of said hook  55  is moved only in counter-clock direction or clockwise direction, and stops at the lower stop point  541  or upper stop point  542  to determine the condition of braking. 
   As shown in  FIG. 8 , when the control button  2  is pressed downward, the stem  5  then moves downward; when stem  5  moves downward; when the stem  5  moves downward, the spring  6  is then in a compressive condition and a rebound force is produced; at the same time, the lower end of the hook  55  would then follow clockwise groove  5 A of the heart-shaped furrow  52  and move to position  541 ; and the stem  5  also reaches the lowest position, at the same time, the lower end of said stem pushes the braking plate  8 , the braking plate  8  then rotates to make its lower end press the upper surface of tape rule, the tape rule is then bent downward into said semi braking furrow  16 ; after the control button  2  is released, the lower end of hook  55  then drops into said upper stop point  542  of said heart-shaped furrow  54  and fixed in the position. The pressing force onto the tape rule is slightly released. However, because the rebound force of spring  6 , the lower end of braking plate  8  still presses the tape rule and the tape rule is still depressed against the semi braking furrow  16 , the tape rule is temporarily stopped and its rewind speed is slowed. 
   When control button  2  is pressed downward again, the stem  5  is pressed downward again, the lower end of hook  55  moves counterclockwisely along the path of heart-shaped furrow  5 B, when the stem  5  reaches the lowest position, the lower end of the hook  55  passes the rib  544 , and after the control button  2  is released, the lower end of hook  55  then drops into the lower stop point  541 . 
   In addition to the above braking action, control button  2  can be pressed to the lowest position and maintained at its lowest position, then the movement of tape rule is temporarily suspended. 
   It can be understood that, according to the construction of present application, the movement of tape rule can be suspended simply by pressing the control button  2  of the housing  1  to move downward, and the control button  2  of the housing  1  can be pressed downward by people&#39;s hand, or by people&#39;s thumb. It is then) an energy-saving measuring tape. 
   Accordingly, from the aforementioned description, the braking structure of measuring tape of present invention of the present invention certainly has the effect of sustaining the tape rule in a steady condition. Although the present invention has been described using a specified embodiment, the examples are meant to be illustrative and not restrictive. It is clear that many other variations would be possible without departing from the basic approach, demonstrated in the present invention.