Abstract:
An opening and shutting apparatus for a flow control to adjust a fluid flow inside a duct, especially, in which a kinematical structure is used, and so the sum of the moment acting on the knob on closing-up the inside of the duct is forced to come to zero, so that the inside of the duct can be stably closed up without special locking projection or spring, etc.

Description:
RELATED APPLICATIONS  
       [0001]     The present disclosure relates to subject matter contained in priority Korean Application No. 10-2004-0042083, filed on Jun. 09, 2004, which is herein expressly incorporated by reference in its entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to an opening and shutting apparatus for a flow control to regulate the fluid flow inside a duct, more specially to an opening and shutting apparatus for a flow control to regulate the fluid flow inside a duct, in which the sum of the moment acting on the knob comes to almost zero by applying the direction of the applied pressure force to be toward the rotary center of the knob, while the pressure applied to a damper door by fluid is transferred to a knob through a link when the duct inside is closed up.  
         [0004]     2. Description of the Related Art  
         [0005]     In general, an opening and shutting apparatus for a flow control is a kind of device, in which a knob is rotated and the rotary power of the knob is transferred to a damper door arranged inside duct through a link, so that the damper door can go round, and thereby opening and shutting a flow path.  
         [0006]     If the damper door is shut by the rotation of the knob, the pressure force by the fluid is applied to the damper door. In order to withstand the pressure and to maintain the closed state, a locking notch or a spring, as shown in  FIG. 1 , had to be specially arranged according to Korean utility model No. 1998-038245.  
         [0007]     If the locking notch or the spring is installed in the opening and shutting apparatus for a flow control, it has following problem that a working process comes to complicated, and disadvantageous that a smooth operation is impossible because the locking notch, etc. has an effect on the operating power of the knob, the cost is increased by the part number, and a quality problem is caused.  
       SUMMARY OF THE INVENTION  
       [0008]     To solve the above-indicated problems, it is, therefore, an object of the present invention to improve the opening and shutting apparatus for a flow control, so that the pressure of fluid can be withstood with aid of kinematical structure without locking notch or spring only when the inside of the duct is closed up, and the closed state therein be maintained.  
         [0009]     Besides, in another aspect of the object, it is to provide a sliding groove of a bent structure, so that opening and shutting of the duct can be adjusted just by the knob rotation of a small angle.  
         [0010]     To achieve the above object, there is provided an opening and shutting apparatus for a flow control which includes of a damper door opening and shutting the path inside the duct; a link, connected with the end of the damper door, in which a sliding groove is shaped; and a knob having a coupling projection to be connected with the sliding groove of the link; wherein a normal line of the points farthest from the rotary center of the knob among the contact points between the sliding groove and the coupling projection of the knob passes the rotary center of the knob when the duct inside is closed up, and more preferably that the sliding groove of the link has a bent shape.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The above aspects and features of the present invention will be more apparent by describing certain embodiments of the present invention with reference to the accompanying drawings, in which:  
         [0012]      FIG. 1  illustrates an opening and shutting apparatus for a flow control using a conventional locking projection in a schematic view;  
         [0013]      FIG. 2  illustrates a first embodiment of the opening and shuttling apparatus for a flow control according to the present invention in a schematic view; and  
         [0014]      FIG. 3  illustrates a second embodiment of the opening and shutting apparatus for a flow control according to the present invention in a schematic view. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]     An opening and shutting apparatus for a flow control according to the present invention includes a damper door  200  for opening and shutting the flow path inside a duct; a knob  300  for, formed into the duct, adjusting the damper door  200  with a rotary power, and having a coupling projection  301  thereon; and a link  400  for, being connected with the damper door  200 , transferring the rotary power of the knob  300  to the damper door  200  from the point of view that the coupling projection  301  of the knob  301  is inserted into the sliding grooves  401  and  402  formed inside the link  300 .  
         [0016]     The damper door  200  opens and shuts the inside of the duct by being axis-supported at the center of the inside of the duct, and, to increase the closing effect and decrease the noise, pads  201  are formed along the circumference of the door damper  200 .  
         [0017]     The link  400  is fixed into the one side end of the damper door  200 , and the damper door  200  and the link have a same rotary center. The sliding grooves  401  and  402  of the link  400 , as shown  FIG. 2 , can have a straight form, and as shown  FIG. 3 , or a bent form.  
         [0018]     Accordingly, because the rotation speed of the link caused by that of the knob  300  depends on the bent angle and form of the sliding groove of the link  400 , the section requiring a fast rotation of the damper door  200  and the section requiring a slow rotation thereof can be adjusted by the shape of the sliding groove.  
         [0019]     The knob  300  transfers the power applied from the outside to the damper door  200  through the link  400 , so that the opening and the shutting of the duct inside can be adjusted. A coupling projection  301  is arranged on the knob  300 , inserted into the sliding grooves  401  and  402  formed in the link  400 , and transfer the rotation power of the knob  300  to the link  400 .  
         [0020]     In view of the process in which the duct inside is closed up, a user rotates the knob  300 , and then the coupling projection  301  arranged on the knob  301  slides in the sliding grooves  401  and  402  of the link  400  by the rotating knob  300  and rotates the link  400 . Accordingly, the rotating link  400  makes the door damper  200 , which has a same rotary axis and whose end is coupled with the link, rotated around the axis.  
         [0021]     If the duct inside, as shown  FIG. 2  or  3 , is closed up by the rotation of the damper door  200 , the pressure of fluid is applied to the damper door  200 . At this time, the power applied to the damper door  200  is transferred to the knob  300  by the link  400 . At this moment, the coupling projection  301  of the knob  300  is located in the end of the sliding grooves  401  and  402  of the link  400 , and then the round coupling projection  301  is surface-contacted with the end of the half-rounded sliding grooves  401  and  402 . Because of the surface contact, numberless many points exist, but the points located in the farthest from the rotary center of the knob among such contact points builds up one line, and the normal line of those indicates the direction of the power which is applied to the knob by the link. In this case, the direction in which the rotary power of the link has an effect on the knob, that is, the direction  302  of the normal line makes for the rotary center  303  of the knob.  
         [0022]     If this structure is provided, the power to make the knob  300  rotated is not applied to the knob. Namely, the sum of the moment applied to the knob comes to zero. Because there exists no rotary power, the pressure of fluid can be withstood and the closed state be maintained without a special coupling notch  1  or spring.  
         [0023]     The effects of the present intention can be summarized as follows:  
         [0024]     Firstly, when the pressure of fluid acting on the door damper is transferred to a coupling projection of knob, the sum of the moment applied to the knob comes to zero by means of the kinematical structure only, without special coupling projection or spring, so that the pressure of fluid can be naturally withstood and the closed state be maintained.  
         [0025]     Secondly, the sliding groove of the link has a bent form, so that the rotating speed of the link can be changed, and accordingly, the opening and shutting speed of the damper door be adjusted. That is, the section wanting the fast rotation of the damper door and the section wanting the slow rotation thereof can be adjusted according to the bent angle of the sliding groove.  
         [0026]     The foregoing embodiment and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. Also, the description of the embodiments of the present invention is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.