Abstract:
A rotary cable assembly to transmit force through a connection cable connected between a pair of pulleys. At least one of the pulleys includes a hollow pulley unit; and a cable holding unit in the pulley unit and rotatable therein in one direction, the holding unit including a slot, for the cable to sit therein, at its outer surface. The pulley unit is disposed is a housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to Korean Application No. 10-2007-0068214, filed on Jul. 6, 2007, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to rotary cable assemblies. 
         [0004]    2. Description of the Related Art 
         [0005]    In manual controllers, such as those provided on vehicle instrument panels, for example, air conditioner knobs, rotation is transmitted between a drive pulley and a driven pulley through an inner cable. The inner cable is often housed in an outer cable, which is provided at one end with a compression coil spring, which biases the first and second pulleys away from each other. 
         [0006]    There is a limit to which the tension between the two pulleys can be managed using only the compression coil spring. Furthermore, when the inner cable stretches out with use, some of the rotation of the drive pulley is not transmitted to the driven pulley. 
       SUMMARY OF THE INVENTION 
       [0007]    Disclosed is a rotary cable assembly to transmit force through a connection cable connected between a pair of pulleys. At least one of the pulleys includes a hollow pulley unit; and a cable holding unit in the pulley unit and rotatable therein in one direction, the holding unit including a slot, for the cable to sit therein, at its outer surface. The pulley unit is disposed is a housing. 
         [0008]    One-way gear teeth are provided on an inner surface of the pulley unit, engaged on one-way gear teeth on the outer surface of the cable holding unit. 
         [0009]    The cable holding unit includes a cable holding body on an outer surface of which the one-way gear teeth are provided. The cable holding unit also includes a handle for rotation of the cable holding body, and a locking hook provided on the cable holding body. The locking hook serves as a rotating shaft of the cable holding unit. 
         [0010]    The pulley unit has a seating depression, with the cable holding unit seated therein. 
         [0011]    The pulley unit has a first cable guide slot to guide the connection cable in a radial direction, and a second cable guide slot around its outer surface to guide the connection cable in a circumferential direction. 
         [0012]    The cable holding body includes a cable connection slot extending radially from its central portion. 
         [0013]    A cable support block is provided in the housing to support and guide retraction of the connection cable into the housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0015]      FIG. 1  is a perspective view of a rotary cable assembly for vehicles according to an embodiment of the present invention; 
           [0016]      FIG. 2  is a flowchart illustrating assembly of the rotary cable assembly of  FIG. 1 ; 
           [0017]      FIG. 3  is a sectional view taken along line A-A of  FIG. 2 ; 
           [0018]      FIG. 4  illustrates a non-operating state of the rotary cable assembly of  FIG. 1 ; and 
           [0019]      FIG. 5  illustrates an operating state of the rotary cable assembly of  FIG. 1 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. 
         [0021]    Embodiments of the present invention provide a rotary cable assembly that applies an appropriate degree of tension to a connection cable  400 , which connects two pulleys to each other, when the connection cable  400  stretches out with use, preventing loss of output. The assembly may be provided to one or both pulleys. 
         [0022]    The pulley or pulleys provided with the assembly each includes a hollow pulley unit  100 , which has one-way internal gear teeth  110  therein; a cable holding unit  200 , to which one end of the connection cable  400  is held, and whose outer surface engages with the one-way internal gear teeth  110 ; and a housing  300 , in which the pulley unit  100  is fastened. 
         [0023]    The pulley unit  100  is generally a circular plate, with the connection cable  400  wound around it. 
         [0024]    A seating depression  270 , into which the cable holding unit  200  is seated, is provided in the pulley unit  100 . The one-way internal gear teeth  110  are disposed on the inner surface of the pulley unit  100 , and have a sawtooth shape, oriented in one direction. The one-way internal gear teeth  110  engage with one-way external gear teeth  210  of the cable holding unit  200 , and thus ensure one-way rotation of the cable holding unit  200 . 
         [0025]    A first cable guide slot  121  is provided in the radial direction of the pulley unit  100  to guide the portion of the connection cable  400  that is connected to the cable holding unit  200 . A second cable guide slot  122  is provided around the outer surface of the pulley unit  100  to guide the connection cable  400  that extends circumferentially from the first cable guide slot  121 . 
         [0026]    A locking hook  240  ( FIG. 1A ) of the cable holding unit fastens the cable holding unit  200  to the pulley unit  100 . An insert hole  101  (FIGS.  2 C′ and  3 ), into which the locking hook  240  is fitted, is provided through a second pulley body  130  ( FIGS. 1 and 3 ) of the pulley unit  100 . Therefore, the cable holding unit  200  is rotatable around the locking hook  240  in one direction, using engagement between the tooth  110  and  210 . 
         [0027]    Referring especially to  FIG. 3 , the pulley unit  100  may generally be made up of a first pulley body  120  and the second pulley body  130 , disposed at either side of the second cable guide slot  122 . 
         [0028]    The cable holding unit  200  may be die-cast, and holds a holding piece  410  ( FIG. 2 ) coupled to the end of the connection cable  400 . When the cable holding unit  200  is rotated, tension is applied to the connection cable  400 . 
         [0029]    As illustrated in  FIG. 1A , the cable holding unit  200  includes a cable holding body  220 , which is seated in the seating depression  270  of the pulley unit  100  and has the teeth  210  on the outer surface thereof; a handle  230 , which protrudes from the cable holding body  220 , enabling rotation of the cable holding body  220 ; and the locking hook  240 . 
         [0030]    In more detail, referring still to  FIG. 1A , the cable holding body  220  has two rows of teeth  210 . A slot  260  is provided between the two rows, so that, when the cable holding body  220  is rotated, the connection cable  400  is wound around the slot  260 . 
         [0031]    Particularly, the holding piece  410  of the connection cable  400  is fastened to the central portion of the cable holding body  220 . Furthermore, a cable connection slot  250 , which extends radially from the central portion of the cable holding body  220 , is provided to guide the connection cable  400  to the cable guide slot  121  of the pulley unit  100 . 
         [0032]    The pulley unit  100  is supported by a housing  300 . To fasten the pulley unit  100  to the housing  300 , a separate hook may be used, or, alternatively, the locking hook  240  may be used. As a further alternative, a bonding agent may be used. 
         [0033]    A cable guide passage, through which the connection cable  400  is drawn into the housing  300 , is provided in the housing  300  adjacent to the cable holding unit  200 . A cable support block  310  ( FIGS. 1 ,  4 , and  5 ), which holds the connection cable  400  and guides it into the housing  300 , is installed in the cable guide passage. Guide pieces  320  are provided in the housing  300  at positions adjacent to the inlet of the cable guide passage to guide the connection cable  400  towards the cable holding unit  200 . 
         [0034]    Therefore, the connection cable  400  extends along the first cable guide slot  121  of the pulley unit  100  under the guidance of the guide pieces  320 , and is fastened to the cable holding body  220  through the cable connection slot  250 . 
         [0035]    Hereinafter, an exemplary process of assembling the above-described rotary cable assembly will be described with reference to  FIG. 2 . The assembly is conducted in the sequence of  FIGS. 2A ,  2 B,  2 C and  2 D.  FIG. 2C  illustrates the combination of FIGS.  2 B and  2 C′. 
         [0036]    The holding piece  410  is fastened to the end of the connection cable  400 , such as through die-casting. 
         [0037]    Thereafter, the holding piece  410  is fitted into the cable holding unit  200 . The cable connection slot  250  guides the direction of the connection cable  400 . 
         [0038]    The pulley unit  100  is prepared, and the cable holding unit  200  is fitted into the pulley unit  100 . The locking hook  240  of the cable holding unit  200  is inserted into the insert hole  101  of the pulley unit  100 , and the teeth  120  are engaged with the teeth  110 . 
         [0039]    Subsequently, the pulley unit  100  is fastened to the housing  300 . Thereafter, the cable support block  310  is provided in the housing  300 . 
         [0040]    The operation of the above-described assembly will be explained herein below. 
         [0041]    As shown in  FIG. 4 , under normal conditions, the teeth  110  engage with the teeth  210 . Thus, the rotary cable assembly is rotatable only in one direction. 
         [0042]    However, in the case where the connection cable  400  is stretched out with use, as shown in  FIG. 5 , when the handle  230  is rotated in one direction to apply appropriate tension to the connection cable  400 , the teeth  210  pass by the teeth  110 , so that the cable holding unit  200  is rotated in the cot-responding direction with respect to the pulley unit  100 . 
         [0043]    The end of the connection cable  400  is rotated along with the cable holding unit  200 , so that part of the connection cable  400  is wound around the cable holding unit  200 . Thereby, the connection cable  400 , which was loose, is pulled taught. 
         [0044]    Since manual control knobs generally have an operational range of motion of ˜180°, the fact that the end of the cable  400  near the holding piece  410  is locked in to rotational alignment with the cable holding unit  200  does not affect operation of the assembly. 
         [0045]    Although preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as defined in the accompanying claims.