Abstract:
A tension regulator employs a first blocking member fixed between a plunger on a propelling member and the blocking device to permit a smooth sliding movement of the propelling member to be achieved via a stable support while the plunger driving the propelling member of the propelling device. Additionally, the reinforced limitation to the sliding movement of the plunger provided by the first blocking member could accordingly prevent the propelling member from an over-protruding incident. Thence, since hydraulic oil is properly blocked by the first blocking member, no leakage of the oil would adversely occur, and no air would unfavorably enter into the sliding space in time of the sliding. Thence, the tension regulator possesses a more stable operation, and a driving safety could be promoted.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a tension regulator, particularly to a tension regulator applied to a timing belt. 
         [0003]    2. Description of the Related Art 
         [0004]    Referring to  FIGS. 1 and 2 , a conventional tension regulator  1  applied to a timing belt comprises a body  11 , an elastic device  12  disposed in the body  11 , a propelling device  13  elongated into the body  11  for being propelled by the elastic device  12 , and a blocking device  14  sealing the body  11  as well as blocking the propelling device  13 . Wherein, the body  11  has a sliding space  111 , whose diameter is uniform and whose interior is capable of filling with hydraulic oil  15 , and an opening  112  formed on the body  11  for the sliding space  111  to communicate with an exterior through the opening  112 . Moreover, the propelling device  13  has a propelling member  131  elongated into the sliding space  111  as well as protruded out of the blocking device  14 , a plunger  132  disposed on the propelling member  131  sliding within the sliding space  111 , a controlling member  133  disposed on the plunger  132 , and a limiting member  134  disposed on the sliding space  111  for limiting a sliding movement of the plunger  132 . Herein, a plurality of apertures  135  are defined on the plunger  132  and controlled by the controlling member  133 . As a result, an on-off function is achievable. 
         [0005]    Referring to  FIG. 2 , the timing belt (not shown) is propelled by the tension regulator  1 ; that is, the plunger  132  is propped by the elasticity of the elastic device  12 , so that the propelling member  131  protruded out of the blocking device  14  is able to thrust the timing belt with proper pressure. Afterward, the propelling member  131  would be triggered by means of the bounce of the timing belt, so that the plunger  132  would retract to engage with the elastic device  12 . Accordingly, the propelling device  13  resumes the action for a next thrust, and thence promotes a regular operation of the timing belt. 
         [0006]    However, the conventional tension regulator  1  has the following shortcomings: 
         [0007]    1. When the replenishment of the hydraulic oil  15  to the conventional tension regulator  1  is artificially sealed with the blocking device  14 , air in the sliding space  111  could not be entirely exhausted; namely, the air still exists in the body  11 . As a result, while the plunger  132  slides in the sliding space  111 , the air would mingle with the flowed hydraulic oil  15 , which incurs the air to pervade the sliding space  111 . Whereby, since the air is contractible, an incomplete operation of the tension regulator would be unfavorably resulted, thereby adversely incurring an unsafe driving. 
         [0008]    Furthermore, in view of the artificial filling of the hydraulic oil  15 , the filling amount of the hydraulic oil  15  is subject to change. That is, the filling quantity of the hydraulic oil  15  would readily affect the air amount contained in the body  11 . However, the more the air is contained in the sliding space  111 , the less the hydraulic oil  15  would be adversely filled, and a stable motion of the plunger  132  is accordingly inaccessible. As a result, the hydraulic oil  15  mixed with air would readily influence the stability of the tension regulator  1 . 
         [0009]    2. In fact, during the operation, the propelling member  131  is merely supported by the plunger  132  and the blocking device  14 . However, since the blocking device  14  is made of rubber, which has a softer characteristic, an unstable support is easily caused in time of stretching or contracting the propelling member  131 . As a result, the propelling member  131  likely becomes slanted. Thereby, the protruding distance of the propelling member  131  is probably varied, and the car is possibly damaged because of the imperfect push from the propelling member  131  on the timing belt. 
         [0010]    3. The plunger  132  is only restricted by the limiting member  134  for attaining an engagement with the body  11 . Herein, because the abovementioned installation is artificial or due to the fact that the propelling of the slanted propelling member  131  with the plunger  132  adversely incurs a burden on the limiting member  134 , the plunger  132  is unable to be properly engaged with the limiting member  134 . Thus, the plunger  132  unavoidably protrudes beyond the limiting member  134 , and the propelling member  131  improperly projects from the body  11 . As a result, the propelling device  13  is unable to offer a precise thrust impinged on the timing belt, and the driving safety is influenced. 
       SUMMARY OF THE INVENTION 
       [0011]    The object of the present invention is to provide a tension regulator applied to a timing belt, which provides a firm support for a propelling member to avoid an over-protruding incident and preferably prevents hydraulic oil from leaking out in view of any undue pressure; whereby, a stable operation of the present invention could be achieved to promote the driving safety. 
         [0012]    The tension regulator applied to a timing belt in accordance with the present invention comprises a body, an elastic device disposed in the body, a propelling device elongated into the body as well as propelled by the elastic device, and a blocking device sealing the body as well as blocking the propelling device. Wherein, a first blocking member is fixed between a plunger of the propelling device and the blocking device for giving a synchronous support, thereby permitting a smooth sliding movement of the propelling device while the plunger drives the propelling member to displace. Furthermore, the arrangement of the blocking member substantially leads to air unable to penetrate into the body during the sliding of the plunger, and the hydraulic oil flowing along with the sliding plunger would not scatter to impact the blocking member. As a result, the hydraulic oil would not readily leak out. In addition, since the first blocking member could reinforce the limitation to the sliding movement of the plunger, the propelling member could be accordingly prevented from an over-protruding incident. Thence, the tension regulator preferably facilitates a stable operation and efficiently promotes a driving safety. 
         [0013]    In this connection, the tension regulator applied to a timing belt as claimed comprises a body, an elastic device disposed in the body, a propelling device disposed in the body for being propelled by the elastic device, and a blocking device sealing the body for blocking the propelling device; wherein, a sliding space being defined in the body for accommodating hydraulic oil, and an opening being defined on the body for the sliding space to communicate with an exterior; the propelling device including a propelling member elongated into the sliding space and protruded out of the blocking device, a plunger connected to the propelling member and allowed sliding within the sliding space, a controlling member installed on the plunger, and a limiting member mounted on the sliding space for limiting a sliding movement of the plunger; a plurality of apertures being defined on the plunger, and an on &amp; off function of the apertures being controlled by the controlling member; 
         [0014]    wherein, a first blocking member being disposed between a plunger and the blocking device as well as engaged with the sliding space; a sliding movement of the propelling member brought about by the plunger would not affect the first blocking member, so that a stable support would be provided to prop up the sliding movement of the propelling member and the hydraulic oil would be prevented from scattering in time of the plunger being moved. 
         [0015]    Preferably, the first blocking member is grasped by a fastener for fixing on the sliding space. 
         [0016]    Preferably, a second blocking member is disposed on the body and clasped by a fastener for fixing on the sliding space; the second blocking member includes a blocking wall, and an accommodating room encompassed by the blocking wall. 
         [0017]    Preferably, the sliding space includes a first area and a second area intercommunicated with the first area as well as disposed near to the opening; the first area has a diameter smaller than a diameter of the second area. 
         [0018]    The advantages of the present invention over the known prior arts will become more apparent to those of ordinary skilled in the art upon reading the following descriptions in junction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a schematic view showing a conventional tension regulator; 
           [0020]      FIG. 2  is a schematic view showing the conventional tension regulator in using; 
           [0021]      FIG. 3  is a perspective view showing a first preferred embodiment of the present invention; 
           [0022]      FIG. 4  is schematic view showing the first preferred embodiment in using; 
           [0023]      FIG. 5  is another schematic view showing the first preferred embodiment in using; 
           [0024]      FIG. 6  is a schematic view showing a second preferred embodiment of the present invention; 
           [0025]      FIG. 7  is a schematic view showing a third preferred embodiment of the present invention; and 
           [0026]      FIG. 8  is a schematic view showing a fourth preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]      FIG. 3  shows a first preferred embodiment of the present invention, a tension regulator  2  adapted for a timing belt comprising a body  21 , an elastic device  22  disposed in the body  21 , a propelling device  23  disposed in the body  21  as well as propelled by the elastic device  22 , and a blocking device  24  sealing the body  21  and blocking the propelling device  23 . Wherein, a sliding space  211  is formed inside the body  21  for being filled with hydraulic oil  25  (shown in  FIG. 4 ). Concurrently, an opening  212  is defined on the body  21  for the sliding space  211  to communicate with the exterior thereby. The propelling device  23  includes a propelling member  231  elongated into the sliding space  211  as well as protruded out of the blocking device  24 , a plunger  232  disposed on the propelling member  231  for sliding inside the sliding space, a controlling member  233  disposed on the plunger  232 , and a limiting member  234  disposed on the sliding space  211  for limiting a sliding movement of the plunger  232 . Herein, the plunger  232  could be alternatively formed by a longer structure for wrapping the elastic device  22  as shown in  FIG. 8 ; the following embodiments mainly depict the plunger  232  structured by a shorter contour so as to engaging with the elastic device  22  as shown from  FIGS. 3 to 7 . Further, a plurality of apertures  235  are defined on the plunger  232  as well as controlled by the controlling member  233  so as to accomplish an on-off function. Herein, a first blocking member  3  is disposed between the plunger  232  and the blocking device  24  as well as fixed to the sliding space  211 ; the first blocking member  3  is substantially grasped by a fastener  31  as an example in this embodiment. 
         [0028]    Referring to  FIGS. 4 and 5 , the timing belt (not shown) is engaged with the tension regulator  2 ; namely, the plunger  232  slides by means of the elastic device  22  providing with the elasticity to push the propelling member  231  toward the timing belt. Accordingly, the timing belt could be properly operated via the related propelling device  23 . Herein, concerning to the manner that the first blocking member  3  is disposed between the plunger  232  and the blocking device  24 , the sliding movement of the plunger  232  could be not only limited by the limiting member  234  but also stably supported by the first blocking member  3  when the propelling member  231  driven by the plunger  232  protrudes outward. Hereby, the first blocking member  3  does not move along with the propelling member  231 , so that the propelling member  231  could be prevented from being slanted while propelling the timing belt. Consequently, the timing belt could be well thrust. Afterward, the propelling member  231  would retract via the bounce provided by the timing belt so as to allow the plunger  232  to resume. Thereby, the propelling device  23  is able to execute its propelling again. Perceptibly, the operating stability of the tension regulator  2  applied to the timing belt is promoted to increase the driving safety. 
         [0029]    In fact, as long as the plunger  232  is moved, the hydraulic oil  25  would be subjected to a compulsive pressure, and such pressure would allow the hydraulic oil  25  to scatter. Hereby, in view of the disposition of the first blocking member  3 , the scattered hydraulic oil  25  would be blocked for not directly impacting the blocking device  24  during the pressing. As a result, the hydraulic oil  25  would not readily seep out of the blocking device  24 . Moreover, the first blocking member  3  is also able to obstruct the air staying inside the sliding space  211  for preventing the hydraulic oil  25  from flowing along with air mingled therewith. Accordingly, the operation related to the invention could be assured to be stable. By the stable support provided by the first blocking member  3 , the plunger  232  driving the protrusion of the propelling member  231  would not slant aside, and the protruding distance out of the body  21  would not vary. In addition, even if the filling of the hydraulic oil  25  into the sliding space  211  is artificially operated, of which the amount is subjectively replenished, the location of the first blocking member  3  could be deemed as a filling extreme. That is, users continue filling the sliding space  211  with the hydraulic oil  25  until the oil level reaches the first blocking member  3  indicative of the filling extreme, so that an adequate replenishment of the hydraulic oil  25  could be preferably guaranteed without over-filling or insufficiency, and the reciprocating operation of the propelling device  23  is steady. Therefore, the tension regulator  2  applied to the timing belt possesses a stable action to promote the driving safety. 
         [0030]      FIG. 6  shows a second preferred embodiment of the present invention. The tension regulator  2  applied to the timing belt is similar to that of the first preferred embodiment. In this embodiment, the tension regulator  2  similarly comprises a body  21 , an elastic device  22 , a propelling device  23  and a blocking device  24 . Wherein, the disposing manner of the first blocking member  3  on the body  21  is similarly to be firmly grasped by the fastener  31  for being fixed on the sliding space  211 . Differently, the first blocking member  3  further includes a first wall  32 , and a receiving room  33  encompassed by the first wall  32 , thereby permitting the first blocking member  3  to be formed like a cup. As a result, no matter the first blocking member  3  is formed as that depicted in the  FIG. 5  or in the  FIG. 6 , the first blocking member  3  is able to obstruct the leakage of the hydraulic oil  25  and prevent the oil from scattering in time of the pressing. Besides the function as mentioned above, the first blocking member  3  is able to preferably obstruct the entry of air, and the hydraulic oil  25  could steadily stay in the receiving room  33 , so that sufficient hydraulic oil  25  could be assured to conduce to a smooth sliding movement of the plunger  232 , and the propelling member  231  could be also accordingly driven and projected with stability. 
         [0031]      FIG. 7  shows a third preferred embodiment of the present invention. The tension regulator  2  applied to the timing belt comprises comparable elements similar to those in the first embodiment like the body  21 , the elastic device  22 , the propelling device  23 , the blocking device  24  and the first blocking member  3 . Differently, in this embodiment the sliding space  211  of the body  21  includes a first area  2111  and a second area  2112  communicated with the first area  2111  as well as disposed near the opening  212 . Further, a second blocking member  4  disposed on the body  21  is firmly grasped by the fastener  31  for fixing to the sliding space  211 . Moreover, the second blocking member  4  has a blocking wall  41 , and an accommodating room  42  encompassed by the blocking wall  41 , thereby allowing the second blocking member  4  to be formed like a cup. Accordingly, the second blocking member  4  is superimposed on the first blocking member  3  as shown in the Figure. Wherein, the first area  2111  has a diameter smaller than a diameter of the second area  2112 . Further, the elastic device  22  could be installed at the first area  2111 , and both the first blocking member  3  and the second blocking member  4  firmly grasped by the fastener  31  are respectively located within the first area  2111  and the second area  2112 . Therefore, the propelling member  231  is able to be well supported by the both first and second blocking members  3 ,  4  to achieve a more stable propelling action without slanting and lead to a more steady thrust from the tension regulator  2  to the timing belt. Accompanying with the dual obstruction provided from the first and the second blocking members  3 ,  4 , it is able to favorably impede scattering the hydraulic oil  25  throughout. It also substantially prevents the entry of the air in the sliding space  211  and the inappropriate protrusion of the propelling member  231 . 
         [0032]    To sum up, the present invention takes advantage of the first blocking member disposed between the plunger and the blocking member inside the sliding space for effectively limiting the sliding movement of the plunger as well as preventing the propelling member from over-protruding. As a result, the hydraulic oil could be obstructed for not impacting the blocking device to avoid a leakage. Therefore, no air would enter into the sliding space while the plunger is moved, and the operating action could be assured to be precise. Thus, in view of the stable operation provided by the tension regulator of the present invention, the driving safety could be preferably promoted. 
         [0033]    While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.