Damper unit

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.

1 . A damper unit comprising: 
 a reel having a spool on which a string is wound and a peripheral rack,    a base for rotatably supporting the reel, said base having a holding portion,    a spiral spring having 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, and    a damper device having a rotatable shaft integral with a gear so that 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 to provide damping force.    
   
   
       2 . A damper unit according to  claim 1 , wherein said holding portion is arranged such that when the reel is retracted, the peripheral rack disengages from the gear of the damper device.  
   
   
       3 . A damper unit according to  claim 2 , wherein said holding portion has an oval holding recess in which the reel seats.  
   
   
       4 . A damper unit according to  claim 3 , wherein said holding recess has a cut-out section so that the string is pulled out from one side of the holding recess through the cut-out section while rotating the reel in the string wind out direction, said gear of the damper device facing the cut-out section through which the string passes.  
   
   
       5 . A damper unit according to  claim 3 , wherein the base has an engaging hook on a bottom side of the holding recess thereof that resiliently deforms upon abutting against a peripheral flange formed in a back end section of the reel and fitted, from that side first, into the holding recess, and subsequently regains its original shape in a position where the reel is fully fitted into the holding recess to thereby catch an upper surface of the peripheral flange.  
   
   
       6 . A damper unit according to  claim 5 , further comprising a cover assembled on an outer end of the reel in front of the holding recess of the base into which the reel is fitted, one end of said string being moldetogether.  
   
   
       7 . A damper unit according to  claim 6 , wherein the peripheral rack and the spool are formed between outer end and back end sections of the reel with the peripheral rack positioned on the outside, and the peripheral rack is provided with a slit opened outwardly at roots of the teeth constituting the peripheral rack for feeding through the string.  
   
   
       8 . A damper unit according to  claim 1 , wherein said sting includes a clip having a section to be fastened to a dampened subject by molding.  
   
   
       9 . A damper unit according to  claim 1 , wherein the rotatable shaft of the damper device has an inner shaft end rotatably housed in a sealed case of viscous fluid and an outer shaft end integral with the gear.