Abstract:
A multi-stage transmission tensioning device for automobile safety comprises a base group ( 1 ), a handle group ( 2 ) and a multi-stage transmission group ( 3 ); the multi-stage transmission group ( 3 ) comprises a transmission shaft ( 25 ) for pivoting both with the base of the base group ( 1 ) and the handle of the handle group ( 2 ), a main rotating shaft ( 28 ) used for winding a long strap ( 31 ), and a transmission wheel fixed on the transmission shaft ( 25 ). A fairly large binding force on the straps ultimately can be achieved from a small force applied to the handle by multiple conversions. Different binding forces in the case of applying the same handle force may be got via the increase or decrease of the transmission stages and the change of the transmission ratio of the transmission at all stages.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a tensioning device for automobile safety which can be used for easily winding the strap on the goods on a variety of cars, trucks, trailers and motorcycles. 
       PRIOR ART OF THE INVENTION 
       [0002]    The tensioning device for automobile safety usually comprises a tensioning device host, a long strap and a short strap, of which the host part adopts the mechanism principle of the anti-reverse ratchet wheel. The handle directly drives the active pawl which rotates the ratchet wheel. While the ratchet wheel directly drives the main rotating shaft, tightening the straps winding on the main rotating shaft. And the locking pawl prevents the reverse of the ratchet wheel, facilitating the straps to be capable of maintaining a certain tension and tying up the goods. 
         [0003]    In accordance with the relevant principles of the mechanics, when a certain force of manpower is applied on the handle, a larger binding force will be put on the strap. The binding force is relatively fixed, mainly depending on the length of the handle. If the binding force is too small to properly tie up the goods, it will cause a traffic safety hazard. Therefore, the increase of the binding force is the direction of the joint efforts of the industry. 
         [0004]    If the forces applied on the handle are the same and it requires increasing the binding force, the general approach is to increase the length of the handle, i.e. lengthening the arm of force. Thus, the entire device will be very long and costly and not convenient to carry, transport and operate. Some tensioning device is designed with a folding handle or telescopic handle. Although it can be used with the short handle when in carrying and transportation while with the long handle when in operation, the structure is complicated and not convenient to operate and is costly. 
       SUMMARY OF THE INVENTION 
       [0005]    It is an object of the present invention to provide a tensioning device for automobile safety with a new structure and being easy to achieve a larger binding force. 
         [0006]    For achieving the above stated object, the multi-stage transmission tensioning device for automobile safety comprises a base group having a base and a handle group having a handle; wherein the base group and the handle group are connected through a multi-stage transmission group; the multi-stage transmission group comprises a transmission shaft for pivoting both with the base of the base group and the handle of the handle group, a main rotating shaft fixed on the base and used for winding a long strap, and a transmission wheel fixed on the transmission shaft; the transmission wheel realizes a rotation state required for binding, a non-rotation state required for locking, and a free state required for unlocking under the action of the base group and the handle group. 
         [0007]    Preferably, the transmission wheel is a ratchet wheel; and the handle group comprises an active pawl mounted on the handle and matched with the ratchet wheel, and an active pawl spring acting on the active pawl, the active pawl can push the ratchet wheel to rotate achieving the rotation state required for binding. 
         [0008]    Preferably, the base group comprises a locking pawl mounted on the base and a locking pawl spring acting on the locking pawl, the locking pawl locks the transmission wheel reversely under the action of the locking pawl spring achieving the non-rotation state required for locking the transmission wheel. 
         [0009]    Preferably, the active pawl mounted on the handle and the locking pawl mounted on the base are respectively located at the same side of the transmission shaft, when the handle is not opened; the front portion of the handle is in cam-shaped which can push the locking pawl, the base has two side walls, and two releasing notches are respectively formed on the upper edges of the two side walls of the base which are provided for the active pawl to get in and be locked, and the free state required for releasing the transmission wheel is achieved under the action of the front portion of the handle and the releasing notches. 
         [0010]    Preferably, the multi-stage transmission group is a two-stage transmission group, and the transmission group further comprises a driving gear coaxially fixed with the ratchet wheel and a passive gear fixed on the main rotating shaft and is engaged with the driving gear. The ratchet wheel and the driving gear both on the transmission shaft are separated by a gasket which is mounted on both the main rotating shaft and the transmission shaft, and the gasket has through holes for the main rotating shaft and the transmission shaft to pass through. 
         [0011]    Preferably, the transmission group is a transmission group with more than two stages, the transmission group further comprises a driving gear coaxially fixed with the ratchet wheel, and a final-stage passive gear provided on the main rotating shaft; the driving gear is engaged with the next-stage passive gear, and an intermediate-stage passive gear is fixed on an intermediate transmission shaft which is mounted on the base; the final-stage passive gear is engaged with the last-stage passive gear. 
         [0012]    Preferably, the handle of the handle group is composed of two handle side plates combined together by a handle fixing plate and a handle fixing shaft, the two handle side plates is provided with corresponding mounting holes for receiving the transmission shaft and the active pawl; three pins are extended from the rear portion of the active pawl, and the handle fixing plate is provided with three through holes for three pins of the active pawl to pass through, the ends of the two side pins are respectively connected with a puller, and the middle pin is sleeved with the active pawl spring and the end of the middle pin passes through the corresponding through hole. 
         [0013]    Preferably, the base of the base group is composed of two base side plates combined together by a base fixing plate and a base fixing shaft, and the two base side plates is provided with corresponding mounting holes for receiving the main rotating shaft, the transmission shaft and the locking pawl; a pin is extended from the rear portion of the locking pawl, and the base fixing plate is provided with a through hole for the pin of the locking pawl to pass through; the pin of the locking pawl is sleeved with the locking pawl spring the two ends of which are respectively against the base fixing plate and the locking pawl; the two base side plates are also provided with a bolt and a nut for connecting a short strap. 
         [0014]    In the operation, the handle group is pushed away to drive the active pawl, the ratchet wheel is driven to rotate by the active pawl, then the transmission shaft is driven to rotate by the rotating ratchet wheel, finally the passive wheel is further driven to rotate by the rotating transmission shaft. As the gears are engaged with each other, the driving gear drives the passive gear to rotate in an opposite direction, ultimately driving the main rotating shaft to wind the strap. 
         [0015]    Compared with the prior art, in this invention, with the use of multi-stage transmission, a fairly large binding force on the straps ultimately may be achieved from a small force applied to the handle by multiple conversions. Different binding forces in the case of applying the same handle force may be got via the increase or decrease of the transmission stages and the change of the transmission ratio of the transmission at all stages. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is an exploded view of a tensioning device for automobile safety in accordance with the first embodiment of the present invention. 
           [0017]      FIG. 2  is a perspective view of the tensioning device in accordance with the first embodiment of the present invention. 
           [0018]      FIG. 3  is a sectional view of the tensioning device in accordance with the first embodiment of the present invention. 
           [0019]      FIG. 4  is a front view of the tensioning device in accordance with the first embodiment of the present invention. 
           [0020]      FIG. 5  is a top plan view of the tensioning device in accordance with the first embodiment of the present invention. 
           [0021]      FIG. 6  is a perspective view of the transmission part in accordance with the first embodiment of the present invention. 
           [0022]      FIG. 7  is a schematic view of the transmission relationship in accordance with the first embodiment of the present invention. 
           [0023]      FIG. 8   a,    FIG. 8   b  and  FIG. 8   c  are schematic views of the operation of the tensioning device in accordance with the first embodiment of the present invention. 
           [0024]      FIG. 9  is a front view of a tensioning device for automobile safety in accordance with the third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0025]    To enable a further understanding of the innovative and technological content of the invention herein, refer to the detailed description of the invention and the accompanying drawings below: 
       Embodiment 1 
       [0026]    The tensioning device for automobile safety shown in  FIGS. 1 ,  2 ,  3 ,  4  and  5 , comprises a base group  1 , a handle group  2  and a multi-stage transmission group  3 . 
         [0027]    The base group  1  is composed of a base, a locking pawl  10  and a locking pawl spring  11 , etc., wherein the base of the base group  1  is composed of two base side plates  4  with the same structure combined together by a base fixing plate  7  and a base fixing shaft  6 (the two side walls of the base of claim  4  is formed by the two base side plates). The two base side plates  4  are not only provided with mounting holes for receiving the fixing plate  7  and the fixing shaft  6 , but also provided with mounting holes for receiving the main rotating shaft  28 , the locking pawl  10  and a plurality of transmission shafts. In addition, the upper edges of the two base side plates  4  is in concave-convex-shaped, and two releasing notches  33  are respectively formed for the active pawl ( 14 ) to get in and be locked. The base fixing plate  7  and the locking pawl  10  are obliquely mounted on the base after being inserted in the corresponding holes in the base side plates  4  respectively through two side portions. The upper portion of the locking pawl  10  turns toward the transmission shaft to match with the ratchet wheel  23  fixed on the transmission shaft  25 . A pin is extended from the rear portion of the locking pawl  10 , which is sleeved with the locking pawl spring  11 . A baffle plate is upwardly folded on the rear portion of the base fixing plate  7 , which is provided with a through hole for receiving the pin of the locking pawl  10  to pass through. The pin of the locking pawl  10  is sleeved with the locking pawl spring  11  the two ends of which are respectively against the locking pawl  10  and the baffle plate of the base fixing plate  7 , resulting in that the locking pawl  10  always drives toward the ratchet wheel  23  under the action of the force of the spring. When the handle is in a closed status after the goods is tied up, the locking pawl  10  is engaged with the ratchet of the ratchet wheel  23  (as shown in  FIG. 8   a ) to prevent the reverse of the ratchet wheel  23 , facilitating the straps to be capable of maintaining a certain tension and tying up the goods. A bolt  8  is mounted in the rear portion of the base, which is tightened by a nut  9  after passing through the hole in the two base side plates  4 . The short strap  32  is then connected to the bolt  8 . 
         [0028]    The handle group  2  is composed of a handle, an active pawl  14  and an active pawl spring  17 , etc. wherein the handle is composed of two handle side plates  13  with the same structure combined together by a handle fixing plate  19  and a handle fixing shaft  18 . In addition, two handle side plates  13  are not only provided with mounting holes for receiving the handle fixing plate  19  and the handle fixing shaft  18 , but also provided with mounting holes  21  for receiving the transmission shaft  25  and mounting holes for receiving an active pawl  14 . The front portions  22  of the two handle side plates  13  are in cam-shaped which can push the locking pawl  10  to be separated from the ratchet wheel  23 . The handle fixing plate  19  and the active pawl  14  are mounted on the handle after being inserted in the corresponding holes in the handle side plates  13  respectively through two side portions. The end portion of the active pawl  14  turns toward the transmission shaft  25  to correspond to the ratchet wheel  23  mounted on the transmission shaft. The rear portion of the active pawl  14  is provided with three pins extended backwardly, and correspondingly the handle fixing plate  19  in the rear portion is provided with a downwardly folded baffle with three through holes for three pins of the active pawl  14  to pass through, wherein two pins are connected with a puller  15  by a rivet, and one pin is sleeved with an active pawl spring  17  before extending through a corresponding through hole of the handle fixing plate  19 , resulting in that the active pawl spring  17  pushes against the active pawl  14  and the baffle plate of the handle fixing plate  19 . The active pawl  14  always drives toward the ratchet wheel  23  under the action of the force of the spring  17 . In addition, a knob is mounted in the rear portion of the handle. In this embodiment, when the handle is in a closed status, the active pawl  14  of the handle and the locking pawl  10  of the base are at the same side of the transmission shaft  25 . 
         [0029]    In this embodiment, the multi-stage transmission group is a two-stage transmission group, as shown in  FIG. 6 , which further comprises a ratchet wheel  23 , a driving gear  24 , a transmission shaft  25 , a main rotating shaft  28  and a passive gear  27 , etc., wherein the main rotating shaft  28  mounted in the main rotating shaft hole  5  of the base is composed by two semicircle shafts. The long strap  31  is winded on the main rotating shaft  28 . Both ends of the main rotating shaft  28  are combined and limited through a pin  29  after it is mounted on the base. Two semicircle holes are formed on the passive gear  27  for receiving two semicircle shafts. Two passive gears  27  are respectively mounted at both ends of the main rotating shaft  28  and located on the outer sides of the base side plates  4 . The transmission shaft  25  is located at the rear of the main rotating shaft  28  and arranged in parallel with the main rotating shaft  28 . A hole  12  and a hole  21  for receiving the transmission shaft are formed in the base and the handle. The transmission shaft  25  is limited by a pin  30  after passing through the corresponding holes. The base and the handle are pivoted with each other via the transmission shaft  25 , which facilitates the handle to rotate relatively to the base. A ratchet wheel  23  and a driving gear  24  are respectively mounted at both ends of the transmission shaft  25  with the ratchet wheel  23  matched with the active pawl  14  and the locking pawl  10  and the driving gear  24  matched with and engaged with the passive gear  27 . And the ratchet wheel  23  and the driving gear  24  both on the transmission shaft  25  are separated by a gasket  26  which is mounted on both the main rotating shaft  28  and the transmission shaft  25 , and the gasket  26  has through holes for the main rotating shaft  28  and the transmission shaft  25  to pass through. 
         [0030]    When in the transmission of the two-stage transmission mechanism (shown in  FIG. 7 ), the ratchet wheel  23  is driven to rotate by the handle group  2 , while the transmission shaft  25  is further driven to rotate by the ratchet wheel  23 . As the driving gear  24  is fixed on the transmission shaft  25 , the driving gear  24  is rotated with the transmission shaft  25  and is engaged with the passive gear  27 , driving the passive gear  27  to rotate in an opposite direction. While the passive gear  27  is fixed on the main rotating shaft  28 , driving the rotation of the main rotating shaft  28 , which causes the long strap  31  to wind on the main rotating shaft  28 . Thus, the operation of the handle is repeated to tighten the straps and tie up the goods. 
         [0031]    With the combination of  FIG. 8   a - 8   c,  the dynamic process of the tensioning device of the Invention when in use is described as below: 
         [0032]    As shown in  FIG. 8   a,  the tensioning device is in a locked status. 
         [0033]    When in operation, as shown in  FIG. 8   b,  a force is applied on the handle group  2  and the ratchet wheel  23  is pushed to rotate by the active pawl  14  connected with the handle group  2 , while the transmission shaft  25  is driven to rotate by the ratchet wheel  23  drives and the driving gear  24  is driven to rotate toward the same direction by the transmission shaft  25 . The passive gear  27  engaged with the driving gear is driven to rotate toward the opposite direction by the driving gear  24 , so that the main rotating shaft  28  is driven to rotate and wind the long strap  31  on the main rotating shaft  28 . The operation of the handle is repeated to obtain the necessary binding force and tie up the goods. 
         [0034]    After the operation is completed, the handle group  2  is folded to the locking status, as shown in  FIG. 8   a.  Then the locking pawl  10  and the ratchet on the ratchet wheel  23  are engaged with each other and the ratchet wheel  23  is non-rotatable. 
         [0035]    The handle group  2  is open when released, as shown in  FIG. 8   c.  The active pawls  14  are placed in two releasing notches  33  of the base side plates  4 . Meanwhile, the locking pawl  10  is pushes against by the front portion  22  of the handle side plate  13 , leading the ratchet wheel  23  and two pawls  10  and  14  to get away, which can be inverted. Then the multi-stage transmission group  3  is in a freely rotatable state, so as to release the tension on the long strap  31 . 
       Embodiment 2 
       [0036]    The difference of this embodiment compared with Embodiment 1 is that: the multi-stage transmission mechanism above two-stage is adopted for the multi-stage transmission group. More transmission pairs can be added between the first-stage transmission and the final-stage transmission. The specific can be carried out as follows: the transmission shaft of Embodiment 1 is taken as one-stage transmission shaft, the driving shaft is provided with the ratchet wheel and the driving gear, while the driving gear is engaged with the gear of the next-stage transmission shaft. The main rotating shaft is taken as the final-stage transmission shaft, the main rotating shaft is fixed with a passive gear engaged with the gear of the previous-stage transmission shaft. By adding the second, third or more stages of transmission gear group between the first stage and the final stage, the required binding force may be obtained. The middle-stage transmission shaft is between the first-stage transmission shaft and the final-stage transmission shaft, which can be mounted in the shaft holds preset in the base. 
       Embodiment 3 
       [0037]    As shown in  FIG. 9 , the difference of this embodiment compared with Embodiment 1 and Embodiment 2 is that: The ratchet wheel is not required but the driving gear is directly used as a ratchet wheel (i.e. the transmission wheel in claim  1  is the driving gear). The active pawl and the locking pawl are directly touched the driving gear, achieving the same function without the ratchet wheel. This embodiment is mainly to have adaptability changes to the driving gear and the active ratchet wheel as well as the locking ratchet wheel. The rest of the structure is substantially the same as the previous embodiments. Therefore, the details will not be described here. 
         [0038]    However, in addition to those set forth in the above embodiments of the invention, different types of modification can also be carried out, but not limited to the above three solutions. For example, the gear transmission is used for the transmission group as described previously. In fact, other forms of gear transmission or chain wheel transmission may be used for the multi-stage transmission group of the invention, as long as such type of transmission can realize the transmission of force between the first-stage transmission shaft provided with a transmission wheel and the final-stage transmission shaft connected with long straps, achieving the required binding force. Moreover, the positions and directions of the ratchet wheel and the gear and the positions and directions of the active pawl and the passive pawl may also be different from those shown in the figures of Embodiment 1, which can be mounted in a different position of the tensioning device but still have the same function.