Abstract:
A sunshade apparatus is disclosed. The apparatus includes a motor adapted to be rotated in both directions, a rope drum rotated by the motor, a pair of cables coupled to and wound around the rope drum, a pair of sliders connected to the pair of cables and moved by rotation of the rope drum, a pair of actuating bars pivotably coupled to the pair of sliders and tilted by relative movement of the sliders, a shade bar pivotably coupled to the other ends of the pair of actuating bars, a screen coupled to the shade bar, and a take-up shaft coupled to the other end of the screen and intended to elastically wind the screen. A drive assembly including the motor and the rope drum is mounted in a trunk to be isolated from an interior of an automobile, preventing transmission of noise from the assembly to the interior. The cables are maintained in tightened condition by a simple element, improving operational reliability of the apparatus.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a sunshade apparatus for an automobile which includes a sunshade screen adapted to be unwound and extended from a take-up roll to intercept sunlight transmitted through a rear window of an automobile.  
           [0003]    2. Description of the Prior Art  
           [0004]    In general, a sunshade apparatus for an automobile is designed to be driven by an electric motor such that a sunshade screen can be conveniently manipulated by a driver seated in a driver&#39;s seat to be extended from and wound around a take-up roll.  
           [0005]    An electric sunshade apparatus is disclosed in EP Patent No. 601,454, which comprises a stationary rod which is provided at its middle point with an upright rail having a rack, a movable frame which is provided at its middle point with a slider engaged to the rail and having a pinion engaged with the rack of the rail such that the movable frame is slidable up and down relative to the stationary rod, a sunshade screen coupled at its both ends to the stationary rod and the movable frame and wound around the movable frame, and a driving motor connected to the movable frame to rotate the pinion.  
           [0006]    In other words, such an electric sunshade apparatus is designed to spread or wind the sunshade screen by the pinion of the movable frame, which is engaged with the rack of the stationary rod and is rotated and thus moved up and down along the rail by the driving motor. Therefore, since a rear window of an automobile is always occupied by the rail having the rack, a rear window becomes unsightly and forms an obstacle to the field of view of a driver.  
           [0007]    In addition, since the movable frame having considerable weight due to the pinion, the slider, the driving motor, a gearbox and the wound screen must be raised so as to spread the sunshade screen, the driving motor is applied with high load and considerable electrical energy is required to operate the sunshade apparatus. Furthermore, since the driving motor and the gearbox are positioned inside an automobile, operational noise thereof is directly transmitted inside of an automobile.  
           [0008]    To overcome the problems occurring in the above electric sunshade apparatus disclosed in EP Patent No. 601,454, Korean Utility Model Registration No. 0182090 allowed to the inventor has been proposed.  
           [0009]    The sunshade apparatus disclosed in Korean Utility Model No. 0182090 is adapted to spread or wind a sunshade screen by raising or lowering a movable rod to which the screen wound around a stationary roll is coupled. More specifically, first and second actuating bars are pivotably connected at upper ends thereof to opposite ends of the movable rod. The first and second actuating bars are also pivotably connected to first and second sliders, which are disposed on a frame to be slid laterally. A pair of idle pulleys are positioned at both sides of the frame. A cable is wrapped over the pair of pulleys, and fixed at its both ends to a driving pulley mounted on the frame with the both ends of the rope being slightly wound around the driving pulley. One of the first and second sliders is fixed to an upper rope section and positioned at one side of the driving pulley, and the other of the sliders is fixed to a lower rope section and positioned at the other side of the driving pulley.  
           [0010]    In the sunshade apparatus, when the driving pulley is rotated clockwise or counterclockwise by a driving motor, the first and second sliders are moved toward or away from each other, thereby causing the first and second actuating bars to be inclined or to be erected. Hence, the movable rod is lowered or raised by the tilting movement of the first and second actuating bars, so that the sunshade screen fixed to the movable rod is elastically wound around the stationary roll or extended upwardly.  
           [0011]    Although the said sunshade apparatus of the inventor can substantially overcome the problems occurring in the electric sunshade apparatus of EP Patent No. 601,454, since the driving means is mounted on the frame and positioned inside of an automobile, it is impossible to fundamentally overcome a problem caused by the operational noise.  
           [0012]    Furthermore, since the power transmission means is comprised of a single wire cable, it is very difficult to provide sufficient tension to the wire cable wrapped over the pulleys, and it is impossible to preserve a precise operation of the device due to relaxation of the wire rope upon use for a long time.  
           [0013]    In addition, since extension of retraction of the sunshade screen is fulfilled by only turning force of the driving motor, delayed actuation and overload are caused in an initial operation. Moreover, since assembled components are loosened by vibrations generated during starting and stopping of an operation, operational reliability is lowered.  
         SUMMARY OF THE INVENTION  
         [0014]    Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a sunshade apparatus for an automobile which is provided with driving means such as a driving motor and a gear box generating operational noise, which are installed to be isolated from a frame positioned in an interior of an automobile.  
           [0015]    Another object of the present invention is to provide a sunshade screen for an automobile which is provided with power transmission means comprised of several cables having different moving ranges to facilitate tight assembly of the cables.  
           [0016]    A further object of the present invention is to provide a sunshade apparatus for an automobile which is improved in operational reliability and durability by increasing initial driving force or reducing vibrations.  
           [0017]    In order to accomplish the above object, the present invention provides a sunshade apparatus comprising: a take-up shaft biased by an elastic element to be rotated in a winding direction; a sunshade screen coupled at its one side to the take-up shaft and wound therearound; a shade bar to which the other side of the sunshade screen is coupled; a frame having first and second sliders slidably engaged therewith; first and second actuating bars pivotably coupled at both ends thereof to the shade bar and the first and second sliders; a drive assembly including a driving motor adapted to be rotated in forward and reverse directions, a worm wheel rotated by the driving motor, and a rope drum engaged with the worm wheel and having a helical groove; first and second transmission cables connecting the rope drum and the first and the second sliders and wound around the rope drum, and a mediate cable connecting the first slider and the second slider; and first and second shock absorbers associated with the first and second sliders.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:  
         [0019]    [0019]FIG. 1 is a plan view of a sunshade apparatus according to the present invention;  
         [0020]    [0020]FIG. 2 is an enlarged cross-sectional view taken along line I-I of FIG. 1;  
         [0021]    [0021]FIG. 3 a  is a plan view of a rope drum of FIG. 2;  
         [0022]    [0022]FIG. 3 b  is a front view of the rope drum of FIG. 2;  
         [0023]    [0023]FIG. 4 is a plan view of a spiral spring of FIG. 2;  
         [0024]    [0024]FIG. 5 is a plan view an embodiment of a rope bush of FIG. 1;  
         [0025]    [0025]FIG. 6 a  is an enlarged cross-sectional view taken along line II-II of FIG. 5;  
         [0026]    [0026]FIG. 6 b  is an enlarged cross-sectional view taken along line III-III of FIG. 5; and  
         [0027]    [0027]FIG. 7 is a plan view of embodiment of shock absorbers of FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]    This invention will be described in further detail by way of example with reference to the accompanying drawings.  
         [0029]    [0029]FIGS. 1 and 2 show a sunshade apparatus for an automobile according to the present invention. As shown in the drawings, the sunshade apparatus according to the present invention includes a sunshade screen  14  wound around a take-up shaft  12 , which is connected to elastic means such as a torsion spring in a frame  10 , a shade bar  16  connected to an upper end of the sunshade screen  14 , first and second sliders  18  and  18 ′ engaged with the frame  10  to be longitudinally slidable, and first and second actuating bars  24  and  24 ′ which are pivotably coupled at lower ends thereof to the first and second sliders  18  and  18 ′ by pivot members  20  and  20 ′, and which are also pivotably coupled at upper ends thereof to opposite ends of the shade bars  16 .  
         [0030]    A drive assembly  26  is detachably mounted on the frame  10 . The first and second sliders  18  and  18 ′ are connected to each other by a mediate cable  28  to be moved together. The first slider  18  is connected to the drive assembly  26  via a first transmission cable  30 , and the second slider  18 ′ is connected to the drive assembly  26  via a second transmission cable  32 . In the frame  10  is positioned a first shock absorber  34  associated with the first slider  18  and a second shock absorber  36  associated with the second slider  18 ′.  
         [0031]    As shown in FIGS. 2, 3 a ,  3   b  and  4 , the drive assembly  26  comprises a gear box  38 , a worm wheel  40 , a rope drum  42 , a gear box cover  44 , and a worm  46  engaged with the worm wheel  40  is fixed to the shaft  48  of a driving motor  50 .  
         [0032]    The driving motor  50  is adapted to be rotated in forward and reverse direction.  
         [0033]    As shown in FIG. 1, an external cable  52  of the first transmission cable  30  and an external cable  54  of the second transmission cable  32  are fixed at ends thereof to the gear box  38 . As shown in FIGS. 2, 3 a  and  3   b , internal cables  56  and  58  of the transmission cables  30  and  32  are directed to the rope drum  42  by guide tubes  60  and  62  formed at the gear box  38 .  
         [0034]    As shown in FIG. 2, the gear box  38  is internally provided with a hollow shaft  64  extended downwardly, onto which a boss  66  of the worm wheel  40  and a boss  68  of the rope drum  42  are rotably inserted.  
         [0035]    Since the worm wheel  40  is formed at its lower portion with a recess  70 , and the rope drum  42  is formed at its upper portion with a protrusion  72 , such that the recess  70  and the protrusion  72  are engaged with each other, the rope drum  42  can be rotated with the worm wheel  40 .  
         [0036]    As shown in FIGS. 2, 3 a  and  3   b , the rope drum  42  is formed at its outer surface with a helical groove  74  into which the internal cable  56  of the first transmission cable  30  and the internal cable  58  of the second transmission cable  32  are wound.  
         [0037]    The rope drum  42  is symmetrically provided at its upper and lower end with two nipple recesses  80  and  82  into which nipples  76  and  78  fixed to ends of the internal cables  56  and  58  are fitted.  
         [0038]    The gear box cover  44  is centrally provided with a boss  84  corresponding the hollow shaft  64  of the gear box  38 , so that the gear box cover  44  is attached to the gear box  38  by means of a screw  86 .  
         [0039]    As shown in FIGS. 2 and 4, a spiral spring  90  is fixed at its inner end  92  to the boss  84  of the gear box cover  44 , and fixed at its outer end  94  to an inner surface  88  of the rope drum  42 .  
         [0040]    That is, when the worm wheel  40  and the rope drum  42  are rotated clockwise by the driving motor  50 , the internal cable  56  of the first transmission cable  30  is wound around the rope drum  42  and the internal cable  58  of the second transmission cable  32  is unwound from the rope drum  42  while winding the spiral spring  90 . On the contrary, when the worm wheel  40  and the rope drum  42  are rotated counterclockwise, the internal cable  56  of the first transmission cable  30  is unwound from the rope drum  42  and the internal cable  58  of the second transmission cable  32  is wound around the rope drum  42  while unwinding the spiral spring  90  to the normal position.  
         [0041]    As shown in FIG. 1, the other ends of the external cables  52  and  54  of the first and second transmission cables  30  and  32  are fitted into cable bushes  96  and  98 , and the cable bushes  96  and  98  are fixed to bent ends  106  of a bracket  104  on which pulleys  100  and  102  are supported.  
         [0042]    As shown in FIGS. 1 and 7, a nipple  76 ′ fixed to the other end of the internal cable  56  of the first transmission cable  30  wrapped over the pulley  100  of the bracket  104  and a pulley  108  of the frame  10  is fitted into a nipple recess  110  of the first slider  18 , and a nipple  78 ′ fixed to the other end of the internal cable  58  of the second cable  32  wrapped over the pulley  102  of the bracket  104  is fitted into a nipple recess  112  of the second slider  18 ′.  
         [0043]    To control tensile force of the mediate cable  28  connecting the first and second sliders  18  and  18 ′ and the first and second transmission cables  30  and  32 , the cable bushes  96  and  98  are formed with a plurality of grooves  116 , and a cutout portion  114  formed at the bent end  106  of the bracket  104  is selectively engaged with any one of the grooves  116  of the cable bushes  96  and  98  to achieve appropriate tensile force, as illustrated in FIGS. 5, 6 a  and  6   b.    
         [0044]    [0044]FIG. 7 illustrates embodiments of the first shock absorber  34  associated with the first slider  18  and the second shock absorber  36 .  
         [0045]    As shown in FIG. 7, the first and second shock absorbers  34  and  36  are constructed such that plungers  124 , which are biased by elastic elements such as compression springs  122  received in housings  120  attached to the frame  10  by screws  118 , are provided at ends thereof with cushion tips  126 , which are to collide with the first and second sliders  18  and  18 ′.  
         [0046]    Alternatively, the first and second shock absorbers  34  and  36  may be substituted with common pneumatic or hydraulic shock absorbers.  
         [0047]    As shown in FIGS. 1 and 2, the drive assembly  26  is detachably mounted on the frame  10  via a bracket  128  by screws  130  and  132 .  
         [0048]    Accordingly, since the drive assembly  26  including the driving motor  50  generating operational noise can be mounted in a trunk of an automobile, which is isolated from an interior of an automobile, a problem caused by operational noise can be solved.  
         [0049]    As shown in FIGS. 1 and 2, when the worm wheel  40  engaged with the worm  46  of the driving motor  50  of the drive assembly  26 , and the rope drum  42  engaged with the worm wheel  40  to be rotated therewith are rotated clockwise by the driving motor  50 , the internal cable  56  of the first transmission cable  30  connected to the first slider  18  is wound around the rope drum  42  while the internal cable  58  of the second transmission cable  32  connected to the second slider  18 ′ is unwound from the rope drum  42 .  
         [0050]    Consequently, the mediate cable  28  connecting the first and second sliders  18  and  18 ′, the internal cable  56  of the first transmission cable  30 , and the internal cable  58  of the second transmission cable  32  are moved counterclockwise, so that the first and second sliders  18  and  18 ′ are moved away from each other in the frame  10 . With the relative outward movement of the first and second sliders  18  and  18 ′, the first and second actuating bars  24  and  24 ′ pivotably coupled to the first and second sliders  18  and  18 ′ are erected as indicated by a double-dash chain line in FIG. 1. As the first and second actuating bars  24  and  24 ′ are erected, the shade bar  16  coupled to the first and second actuating bars  24  and  24 ′ pulls out the sunshade screen  14  from the take-up shaft  12 , thereby enabling a rear window of an automobile to be shaded.  
         [0051]    At this point, since the rope drum  42  is rotated clockwise during deceleration while winding the spiral spring  90  fixed at its one end to the inner surface of the rope drum  42  and at its other end to the boss  84  of the gear box cover  44 , rapid movement of the first and second sliders  18  and  18 ′ can be prevented and a part of turning force of the driving motor  50  is stored in the spiral spring  90 .  
         [0052]    In the first and second shock absorbers  34  and  36 , cushion tips  126  of the plungers  124 , which compress the elastic elements  122 , push the first and second sliders  18  and  18 ′ by restoring force of the elastic elements  122 , so that initial driving force of the first and second sliders  18  and  18 ′ is increased, thereby permitting the first and second sliders to be smoothly moved.  
         [0053]    When the worm wheel  40  and the rope drum  42  are rotated counterclockwise, the internal cable  56  of the first transmission cable  30  coupled to the first slider  18  is unwound from the rope drum  42  while the internal cable  58  of the second transmission cable  32  coupled to the second slider  18 ′ is wound around the rope drum  42 .  
         [0054]    Accordingly, the mediate cable  28  connecting the first and second sliders  18  and  18 ′, the internal cable  56  of the first transmission cable  30 , and the internal cable  58  of the second transmission cable  32  are moved clockwise, so that the first and second sliders  18  and  18 ′ are moved toward each other in the frame  10 , as shown in FIGS. 1 and 7. With the relative inward movement of the first and second sliders  18  and  18 ′, the first and second actuating bars  24  and  24 ′ pivotably coupled to the first and second sliders  18  and  18 ′ are inclined to the horizontal position as indicated by a solid line in FIG. 1. As the first and second actuating bars  24  and  24 ′ are inclined, the shade bar  16  coupled to the first and second actuating bars  24  and  24 ′ is lowered, thereby allowing the sunshade screen to be retracted and wound around the take-up shaft  12 .  
         [0055]    At this point, since rotational speed of the rope drum  42  is accelerated by the restoring force of the spiral spring  90 , it is possible to wind the sunshade screen  14  rapidly.  
         [0056]    As best seen in FIG. 7, when the first and second sliders  18  and  18 ′ are moved closer to each other, that is, when winding of the sunshade screen  14  is almost completed, the cushion tips  126  fixed to ends of the plungers  124  of the first and second shock absorbers  34  and  36  first collide with the first and second sliders  18  and  18 ′, thereby compressing the elastic elements  122 . At this point, the elastic elements  12  absorb impact of rapid winding of the sunshade screen, thereby achieving soft landing of the first and second actuating bars  24  and  24 ′ and the shade bar  16 , toward the frame  10 . As such, the sunshade apparatus of the present invention enables the sunshade screen  14  to be completely wound around the take-up shaft  12  while absorbing impact of its rapid retraction.  
         [0057]    As described above, the sunshade apparatus for an automobile according to the present invention provides advantages as follows.  
         [0058]    Since the rope drum  42  is gently rotated by the spiral spring  90  when the sunshade screen  14  is raised, rapid movement of the first and second sliders  18  and  18 ′ is prevented, thereby enabling smooth extension of the sunshade screen.  
         [0059]    On the contrary, since the rope drum  42  is rapidly rotated by the spiral spring  90  when the sunshade screen  14  is lowered, the first and second sliders  18  and  18 ′ can be quickly moved, thereby enabling quick retraction of the sunshade screen.  
         [0060]    Moreover, when the sunshade screen  14  is raised, initial operation of the sunshade apparatus can be facilitated by increased initial driving force. When the sunshade screen is lowered, the sunshade screen can be gently wound around the take-up shaft.  
         [0061]    Furthermore, since the drive assembly serving as a source of noise is mounted in a trunk isolated from an interior of an automobile, noise of the sunshade apparatus can be eliminated.  
         [0062]    In addition, since the first and second transmission cables  30  and  32  are always maintained in a tightened condition, it is possible to prevent decrease of operational reliability due to loosening of the transmission cables  30  and  32  even though the sunshade apparatus is used for a long time.  
         [0063]    Although a preferred embodiment of the present invention has been described 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 disclosed in the accompanying claims.