Abstract:
A damper unit includes a reel having a spool on which a string is wound and a peripheral rack, and a base rotatably supporting the reel and having a holding portion. A spiral spring has an inner end connected to the holding portion and an outer end connected to the reel for accumulating a biasing force to cause the reel to rotate in a string winding direction in response to rotation of the reel in a string withdrawing direction. A damper device has a rotatable shaft integral with a gear. When the string is pulled out, the spiral spring is resiliently deformed to displace the reel to one side of the base to engage the peripheral rack of the reel with the gear of the damper device.

Description:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT  
       [0001]     The present invention-relates to an improvement to a damper unit that includes a wire material that is housed by winding so as to be pulled out, and dampens the pull-out motion of the wound wire only when it is pulled out.  
         [0002]     Japanese Unexamined Patent Publication No. 2004-175151 discloses a damper unit that includes a gear rotatably housed in a case, a wire or wire-like cord which is wound around the core of the gear, a power spring for accumulating resilient force when the wire is pulled out, and a one-way damper that engages with the gear. The damper unit is configured to dampen the rotation of the gear only when the gear is rotated in the direction in which the wire is pulled out. According to this damper unit, connecting a glove box body to the pulled-out end of the wire while mounting the case to the vehicle body, for example, can dampen the motion of the glove box body only when the glove box body is opened. During the closing operation of the glove box body, the wire is rewound around the core of the gear as the spring resiliently regains its original shape. Since the rotation of the gear is not dampened in this instance, the wire is rewound smoothly.  
         [0003]     An object of the present invention is to make the same function as that of the damper unit disclosed in the aforementioned patent document without the use of a one-way damper.  
         [0004]     Further objects and advantages of the invention will be apparent from the following description of the invention.  
       SUMMARY OF THE INVENTION  
       [0005]     In order to achieve the aforementioned object, the damper unit according to the present invention comprises the following features (1)-(8). 
    (1) a reel, a base rotatably holding the reel, a spiral spring for the reel accumulating bias force to cause the reel to perform normal rotation by utilizing the reverse rotation of the reel, and a damper member,     (2) the reel has a spool around which a wire material is wound, and a peripheral rack,     (3) the base having a holding recess for the reel, oval in shape with a major axis and a minor axis,     (4) the spiral spring has the spring center (inner end) fixed substantially to the center of the holding recess and the outer spring end fixed to the reel,     (5) the damper member has a rotating shaft with the inner shaft end rotatably housed in a sealed case of viscous fluid and the outer shaft end including a gear,     (6) the wire material is pulled out from one side of the holding recess of the base across the minor axis (viz., essentially in the direction of the major axis) while rotating the reel in reverse,     (7) the gear of the damper member faces a cut-out section formed on a side of the holding recess so as to be intersective with the major axis, and     (8) a pull-out operation of the wire material causes the movement of the reel essentially along the major axis to one side (viz., one end of the oval shape) of the holding recess while resiliently deforming the spiral spring in the direction of the major axis of the holding recess, the movement causing the peripheral rack of the reel to engage with the gear of the damper member.    
 
         [0014]     According to this construction, the pull-out motion of the wire material is dampened when it is pulled out from the reel, while, on the other hand, the reel is allowed to perform normal rotation by utilizing the function of spiral spring to thereby smoothly rewind the pulled-out wire material without incurring the damping force of the damper member when the pull-out force applied to the wire material ceases.  
         [0015]     Alternatively, an engaging hook may be formed on the bottom side of the holding recess of the base that resiliently deforms upon abutting against the peripheral flange formed in the back end section of the reel being fitted, from that side first, into the holding recess, and subsequently regains its original shape in the position where the reel is fully fitted into the holding recess to thereby catch the upper surface of the peripheral flange.  
         [0016]     According to this construction, the rotatable reel can be assembled with the base with a one-touch operation, by snapping the reel into the holding recess of the base.  
         [0017]     Alternatively, one end of the wire material may be fixed to the cover assembled on the outer end section of the reel, in front of the holding recess of the base into which the reel is fitted, by insert molding using that end of the wire material as an insert, the peripheral rack and the spool may be formed between the outer end and back end sections of the reel with the peripheral rack positioned on the outside, and the peripheral rack may be provided with a slit opened outwardly at the roots of the teeth constituting the peripheral rack for feeding through the wire material.  
         [0018]     According to this construction, by assembling the reel with the cover, the end portion of the wire material can be securely joined with the reel and, at the same time, the wire material fixed to the cover can be conveniently wound around the spool through the aforementioned slit.  
         [0019]     Alternatively, a clip having a section to be fastened to the dampened subject may be fixed to the other end of the wire material by insert molding using that end of the wire material as an insert. According to this construction, that end of the wire material can be securely connected to the dampened subject via the clip by inserting the pair of bosses into mounting holes or the like that are formed in the dampened subject in a one-touch operation.  
         [0020]     According to the damper unit in the present invention, while the damper member having the gear is capable of damping the rotation of the gear in either the normal or reverse direction, only the reverse rotation of the reel during the pull-out operation of the wire is dampened. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  is a perspective view of damper unit FIGS.  2 ( a ),  2 ( b ) and  2 ( c ) shown components which form the damper unit shown in  FIG. 1 .  
         [0022]      FIG. 3  is a top plan view of an assembly of the components shown in FIGS.  2 ( b ) and  2 ( c ) and depicts the situation wherein the wire is not drawn out.  
         [0023]      FIG. 4  is a partial sectional view of the assembly shown in  FIG. 3 .  
         [0024]      FIG. 5  is a top plan view of the assembly shown in  FIG. 4  depicting the situation wherein the wire is drawn out from the damper.  
         [0025]      FIG. 6  is a partial sectional view of the damper unit shown in  FIG. 5 .  
         [0026]      FIG. 7  is a sectional view taken along section line  7 - 7  of  FIG. 3 .  
         [0027]      FIG. 8  is a top plan view of a base.  
         [0028]      FIG. 9  is a back view of the damper D (wire material W is omitted).  
         [0029]      FIG. 10  is a sectional view of the reel taken along section line  10 - 10  of  FIG. 11 .  
         [0030]      FIG. 11  is a sectional view of the reel taken along line  11 - 11  in  FIG. 10 . 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0031]     In the following, an exemplary embodiment of the invention will be explained with reference to  FIGS. 1-11 .  
         [0032]      FIGS. 1, 3 ,  5 ,  7 , and  9  show the damper unit D in one embodiment of the present invention;  FIG. 3 , in particular, shows the state in which the wire material W is not pulled (drawn out of the damper D), while  FIG. 5  shows the state in which the wire material W is pulled out.  FIG. 4  shows a section of the damper unit D in the state shown in  FIG. 3 , and  FIG. 6  shows a section of the damper unit D in the state shown in  FIG. 5 . FIGS.  2 ( a ),  2 ( b ) and  2 ( c ) show the components of the damper D when taken apart.  FIG. 8  is a view of the base  2  in the state shown in  FIG. 3  in which the reel  1  is omitted for better understanding of the internal layout thereof.  FIGS. 10 and 11  show the reel  1 .  
         [0033]     The damper unit D, in this embodiment, includes a wire material W that is housed wound so as to be pulled out, and dampens the pull-out motion of the wound wire material W only when it is pulled out. The wire material W, can be any type of wire as exemplified by a round wire, oval wire, cord, copper wire, piano wire or the like.  
         [0034]     The damper unit D is typically used to dampen the motion of the dampened subject, such as a lid, door, and drawer, which is connected to the pulled-out end (end Wb) of the wire material W and pulls out the wire material W by moving, through the aforementioned damping of the pull-out motion of the wire material W. More specifically, the damper unit D can be used, for example, to dampen the opening motion of a lid of a storage unit by connecting the pulled-out end of the wire material W of the damper unit D, which is attached to the storage unit, to the lid that closes the opening of the storage unit so that the wire material W is pulled out when the cover is opened.  
         [0035]     The damper unit D in this embodiment of the invention includes: 
    (1) a reel  1 ,     (2) a base  2  that rotatably supports the reel  1 ,     (3) a spiral spring  3  for the reel  1  that accumulates bias force to rotate the reel  1  in the normal direction by using the reverse rotation of the reel  1 , and     (4) a damper member  4 . 
 
 (Reel  1 ) 
   
 
         [0040]     The reel  1  has a spool  10  around which the wire material W is wound, and a peripheral rack  11 . The reel  1  has a short cylindrical portion  12 , and a disc  13  with one surface integrally connected to one end of the cylindrical portion  12 . The other surface of the disc  13  represents the outer end section  1 ′ of the reel  1 . The outer diameter of the disc  13  is larger than the outer diameter of the cylindrical portion  12 , and a peripheral surface  13   a  is formed between the outer edge of the disc  13  and the outer peripheral surface of the cylindrical portion  12 . In the center of that other surface of the disc  13 , there is provided a cylindrical sleeve  14  with one end integrally connected to that surface and projecting in the direction perpendicular to that surface. Both ends of the sleeve  14  are open, and the inside thereof communicates with the inside of the cylindrical portion  12 .  
         [0041]     At the other end of the cylindrical portion  12 , a peripheral flange  12   a  is formed around that cylindrical end. In the example shown in the figures, the space between the aforementioned disc  13  and the peripheral flange  12   a  functions as the spool  10 . At the edge of the disc  13 , a plurality of teeth are formed at equally spaced intervals over the entire periphery of the disc  13 , and this edge portion of the disc  13  functions as the peripheral rack  11 .  
         [0042]     A cover  15  is assembled on the outer end section  1 ′ of the reel  1  facing away from the recess of base  2  into which the reel  1 , is fitted. More specifically, the cover  15  has a through hole  15   a  in the center thereof to allow the sleeve  14  of the reel  1  to pass through. It also has a first portion  15   b , which has a long curved outer edge along the imaginary arc around the through hole  15   a , and a second portion  15   c , which is located on the opposite side of the first portion  15   b  and has a short curved outer edge along the aforementioned imaginary arc and a narrower width than the first portion  15   b . The cover  15  also has risers  15   d  along the respective curved outer edges of the first portion  15   b  and the second portion  15   c . It also has a flange  15   e  extending outwardly from the respective projecting ends of the risers  15   d  of the first portion  15   b  and the second portion  15   c.    
         [0043]     The end Wa of the wire material W is fixed to the cover  15  by insert molding using the end Wa as an insert. In the example shown in the figures, more specifically, the cover  15  is formed by insert plastic molding upon inserting and embedding the end Wa of the wire material W in the wall thickness of the second portion  15   c  in a location between the through hole  15   a  and the curved outer edge of the second portion  15   c . The terminal of the embedded portion of the wire material W projects outwardly from the end face of one of the straight edges  15   f  formed on both sides of the curved outer edge of the second portion  15   c ; the wire material W is extended through the second portion  15   c  in the direction substantially perpendicular to that end face to extend out from the end face of the other straight edge  15   f.    
         [0044]     The other surface of the disc  13  of the reel  1  has arc ribs  13   b  projecting from that surface in four locations along the arc of the imaginary circle around the sleeve  14 . An engaging hook  13   c  is formed at the projecting end of each arc rib  13   b  so as to project towards the inside of the curve.  
         [0045]     The peripheral rack  11  of the reel  1  is provided with a slit  11   a  opened outwardly at the root of two adjacent teeth among the plurality of teeth constituting the peripheral rack  11  and extending inwardly into the reel  1  for threading the wire material W. That is, in the example shown in the figures, the slit  11   a  is formed by cutting out a section of the aforementioned disc  13  of the reel  1  that projects past the cylindrical portion  12 .  
         [0046]     The insertion of the risers  15   d  of the cover  15  into the spaces between the arc ribs  13   b  of the reel  1  causes the flange sections  15   e  formed on the risers  15   d  to abut against the engaging hooks  13   c  formed on the arc ribs  13   b . This allows the arc ribs  13   b  to flex outwardly once, and then allows the engaging hooks  13   c  to catch the flange  15   e  from above as the arc ribs  13   b  resiliently regain their original shapes in the position where the flange  15   e  is fitted below the engaging hooks  13   c , thereby enabling the assembly of the cover  15  on the outer end section  1 ′ of the reel  1  with a one-touch operation.  
         [0047]     Therefore, by assembling the reel  1  with the cover  15 , the end portion Wa of the wire material W can be securely joined with the reel  1  and, at the same time, the wire material W fixed to the cover  15  can be conveniently wound around the spool  10  through the aforementioned slit  11   a . A projection  15   g  that fits into the slit  11   a  while the wire material W is threaded through the slit  11   a  is formed in the curved outer edge of the first portion  15   b  of the cover  15  in the location near the straight edge  15   f  where the wire material extends out from the second portion  15   c . Moreover, an anchor  12   b  for the outer end  30  of the spiral spring  3 , with the upper end integrally connected to one surface of the disc  13  and projecting downwardly, is formed inside the cylindrical portion  12  of the reel  1  in close proximity to the inner surface.  
         [0048]     The aforementioned other end Wb of the wire material W is fixed to a clip  5 , which includes fastening sections  51  for the dampened subject, by insert molding using the end Wb as an insert. More specifically, the clip  5  is formed by plastic molding so that the end Wb of the wire material W that will be pulled out of the reel  1  when the middle portion of the wire is wound around the spool  10  of the reel  1  is embedded through the wall thickness of the bulged section  50  formed on one long side of the substantially rectangular sheet-formed clip  5 . In the example shown in the figures, moreover, a boss  51   a  constituting the aforementioned fastening section  51  is formed at each corner of the short side of the clip  5  facing towards the middle portion of the wire material W. The end Wb of the wire material W can be securely connected to the dampened subject via the clip  5  by inserting the pair of bosses  51   a  into mounting holes or the like that are formed in the dampened subject in a one-touch operation.  
         [0000]     (Base  2 )  
         [0049]     The base  2  has a holding recess  20  for the reel  1 , which is oval in shape and has minor axis x and major axis y. The holding recess  20  is formed by allowing one surface of the mounting board  21  to cave in towards the other surface. In the example shown in the figures, the holding recess  20  is larger in diameter on the entrance side of the recess and smaller in diameter on the bottom side of the recess. A stepped surface  20   c  is formed between the large-diameter portion  20   a  and the small-diameter portion  20   b . In the example shown in the figures, moreover, the reel  1  is rotatably fitted into the holding recess  20  so that the spool  10  of the reel  1  is housed in the small-diameter portion  20   b  and the disc  13  is housed in the large-diameter portion  20   a . Holes  21   a  for screws or the like are formed in the mounting board  21  to mount the base  2 , or the damper unit D. The damper unit D can be mounted on an inner wall surface of a storage unit, for example, by utilizing these holes  21   a.    
         [0050]     Engaging hooks  22 , which are formed on the bottom side of the holding recess  20  of the base  2 , resiliently deform upon abutting against the peripheral flange  12   a  formed at the back end section  1 ″ of the reel  1  being inserted, from that side first, into the holding recess  20 , and regain their original shapes in the position where the reel  1  is fully inserted into the holding recess  20  to thereby catch the upper surface of the peripheral flange  12   a . The engaging hooks  22 , which face the engaging surfaces  22   a  towards the bottom of the holding recess  20 , are formed on both sides of the minor axis x of the holding recess  20 .  
         [0051]     With this, the reel  1  can be rotatably assembled with the base  2  with a one-touch operation, by snapping the reel  1  into the holding recess  20  of the base  2 .  
         [0052]     The dimension of the minor axis x of the small-diameter portion  20   b  of the holding recess  20  is substantially equal to the diameter of the peripheral flange  12   a  of the reel  1 , but the dimension of the major axis y of the small-diameter portion  20   b  is slightly larger than the diameter of the peripheral flange  12   a . The reel  1  is rotatably held in the holding recess  20 , while movement of the reel  1  along the major axis y to some extent is tolerated.  
         [0053]     The wire material W is pulled out from one of the sides of the holding recess  20  of the base  2  essentially along the major axis y, while rotating the reel  1  in the reverse direction, and the later described gear section  40   a  of the damper member  4  faces the cut-out section  23  formed on that side of the holding recess  20 .  
         [0054]     As best seen in  FIG. 1 , on a side of the holding recess  20  which lies on the major axis y (see  FIG. 8 ), a pull-out window  24  is formed by cutting out one portion of the side wall of the small-diameter portion  20   b  of the holding recess  20 . The end Wb of the wire material W that is wound around the spool  10  of the reel  1  is pulled out through the pull-out window  24  toward the lower side of the mounting board  21  (as seen in  FIG. 1 ), and fed through the guide window  21   b , which is substantially rectangular in shape and formed ahead of the pull-out window  24 , to come out on the lower side of the mounting board  21  and extend out therefrom.  
         [0055]     A fitting hole  21   c  (see  FIG. 8 ) for the damper member  4  is formed on one side of the guide window  21   b ; the fitting hole is connected to the holding recess  20  through the cut-out section  23 , which is formed by cutting out one portion of both the large-diameter portion  20   a  and the small-diameter portion  20   b  of the folding recess  20 , and runs through the mounting board  21 .  
         [0056]     One portion of the gear  40   a  of the damper member  4  that is assembled to the fitting hole  21   c  from the side of the mounting board  21  enters inside the large-diameter portion  20   a  of the holding recess  20  through the cut-out section  23 .  
         [0057]     Moreover, a cylindrical projection  25  is formed substantially in the center of the holding recess  20  to project from the bottom of the holding recess  20  towards the entrance of the recess. The cylindrical projection  25  has a depth from the projecting end to the base, and is divided into two sections by the slit  25   a  that runs in the center. In the example shown in the figures, by inserting the center end  31  of the spiral spring  3  into the slit of the cylindrical projection  25 , the center end  31  of the spring is fixed in the substantial center of the holding recess  20 .  
         [0000]     (Spiral Spring  3 )  
         [0058]     The center end  31  of the spiral spring  3  is fixed at the substantial center of the holding recess  20 , and the outer end  30  of the spiral spring is fixed to the reel  1 . The spiral spring  3  is constructed to have an outer diameter and width that can be fitted inside the cylindrical part  12 . When the reel  1  is rotated in reverse (clockwise direction in  FIG. 3 ) by pull-out operation of the wire material W that is wound around the reel  1 , the spiral spring  3  is tightened to thereby accumulate the bias force utilized in the normal rotation of the reel  1 .  
         [0059]     At the same time, one of the radii z 1  of the spiral spring  3  from the center end  31  along the major axis y that passes through the center of the holding recess  20 , is substantially equal to the other radius z 2  across the minor axis x of the holding recess  20  when a pull-out operation of the wire material W is not performed. ( FIG. 8 ).  
         [0000]     (Damper Member  4 )  
         [0060]     The damper member  4  has a rotating shaft  40 ; the inner shaft end (omitted in the figures) is rotatably housed in the case  41  containing a viscous fluid, and the outer shaft end has a gear  40   a.    
         [0061]     The damper member is so configured that the viscous fluid sealed in the case  41  dampens the rotation of the rotating shaft  40 . The rotational axis of the rotating shaft  40  is substantially in parallel to the rotational axis of the reel  1  held in the holding recess  20 . As such a viscous fluid, silicon oil, grease or the like is typically used.  
         [0062]     In this embodiment, moreover, when a pull-out operation of the wire material W is not performed, the peripheral rack  11  of the reel  1  does not engage the gear  40   a  of the damper member  4 . However, when a pull-out operation of the wire material W is performed, the pull-out force causes the reel  1  to move essentially along the major axis y to one end of the holding recess  20  while also resiliently deforming the spiral spring in the direction of the major axis y of the holding recess  20 . This movement allows the peripheral rack  11  of the reel  1  to engage with the gear  40   a  of the damper member  4 .  
         [0063]     More specifically, when the pull-out force is applied to the wire material W, the reel  1  held within the holding recess  20  is moved to one end of the holding recess  20  across the minor axis x while being rotated in reverse, in the direction to reel out the wound wire material W. At the same time, the spiral spring  3  is resiliently deformed along the major axis y of the holding recess  20  so as to elongate the radius z 1  from the spring center  31  on one side of the holding recess  20  across the minor axis x, while being tightened by this reverse rotation. ( FIG. 5 ) When the pull-out force applied to the wire material W ceases, the spiral spring  3  regains its original shape so as to make the radius z 1  from the spring center  31  on one side of the holding recess  20  substantially equal to the radius z 2  on the other side across the minor axis x, and thus the reel  1  performs a normal rotation utilizing the function of the spiral spring  3  without allowing the peripheral rack  11 , which has returned to the position prior to the aforementioned movement, to engage with the gear  40   a  to thereby rewind the pulled-out wire material W.  
         [0000]     (Function)  
         [0064]     Having been constructed with the above features, the damper unit D in this embodiment functions to dampen the pull-out motion of the wire material W when it is pulled out from the reel  1 , while, on the other hand, allowing the reel  1  to perform normal rotation by utilizing the spiral spring  3  thereby smoothly rewinding the pulled-out wire material W without incurring the damping force of the damper member  4  when the pull-out force applied to the wire material W ceases. When the damper unit D is disposed in a storage unit, and the pulled-out end (end Wb) of the wire material W is connected to the lid that closes the opening of the storage unit (the dampened subject), for example, only the opening operation of the cover is dampened. During the closing operation of the opened lid, the damper unit. D smoothly rewinds the wire material W in accordance with the amount of slack, since pull-out force, or tension, is not applied to the wire material W.  
         [0065]     The disclosure of Japanese Patent Application No. 2004-228286 filed on Aug. 4, 2004 is incorporated herein.  
         [0066]     While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims.