Retractable apparatus

Abstract

A retractable apparatus includes a housing unit, a rotating unit and a retractable unit. The housing unit is formed with a housing teeth set therein. The rotating unit is disposed in and rotatable relative the housing unit. An end portion of the rotating unit is formed with a shaft teeth set engaging the housing teeth set. The shaft teeth set and the housing teeth set cooperatively prevent the rotating unit from rotating relative to the housing unit in a first turning direction. The shaft teeth set cooperates with the housing teeth set to allow the rotating unit to rotate in a second turning direction opposite to the first turning direction relative to the housing unit.

What is claimed is: 
     
         1 . A retractable apparatus comprising:
 a housing unit formed with a housing teeth set therein;   a rotating unit disposed in and rotatable relative said housing unit, an end portion of said rotating unit being formed with a shaft teeth set engaging said housing teeth set, said shaft teeth set and said housing teeth set cooperatively preventing said rotating unit from rotating relative to said housing unit in a first turning direction, said shaft teeth set cooperating with said housing teeth set to allow said rotating unit to rotate in a second turning direction opposite to said first turning direction relative to said housing unit; and   a retractable unit, a portion of said retractable unit being assembled and wound on said rotating unit, another portion of said retractable unit protruding out of said housing unit, and being able to be pulled so as to lengthen an extent of said retractable unit out of said housing unit, and to drive said rotating unit to rotate in the second turning direction.   
     
     
         2 . The retractable apparatus as claimed in  claim 1 , further comprising a resilient unit assembled between said housing unit and said rotating unit, and a switching unit, said switching unit including a biasing member disposed between said housing unit and the other end of said rotating unit opposite to said shaft teeth set, and a pushing member extending through said housing teeth set and abutting against said shaft teeth set, said pushing member protruding out of said housing unit, and being depressable to switch said rotating unit between a first state and a second state, in the first state, said shaft teeth set engaging said housing teeth set, and said rotating unit being rotatable only in the second turning direction, in the second state, said shaft teeth set being disengaged from said housing teeth set, and allowing said resilient unit to drive said rotating unit to rotate in the first turning direction. 
     
     
         3 . The retractable apparatus as claimed in  claim 2 , wherein said housing unit comprises a housing body, and a cover body covering said housing body, said housing body comprising a top housing portion receiving said rotating unit, said retractable unit and said resilient unit, and a bottom housing portion extending downwardly from said top housing portion, said bottom housing portion being for disposition of said biasing member of said switching unit, said cover body being formed with said housing teeth set. 
     
     
         4 . The retractable apparatus as claimed in  claim 3 , wherein said rotating unit comprises a rotating shaft abutting between said housing teeth set of said cover body and said biasing member of said switching unit, said rotating shaft comprising a top shaft portion formed with said shaft teeth set, a bottom shaft portion inserted into said bottom housing portion of said housing body and abutting against said biasing member, and a middle shaft portion located in said top housing portion of said housing body and permitting said retractable unit to be assembled and wound thereon. 
     
     
         5 . The retractable apparatus as claimed in  claim 4 , wherein said rotating unit further comprises a ring unit extending radially and outwardly from said rotating shaft to form a ring, said ring unit being located between said top and middle shaft portions, said resilient unit being a spiral spring disposed on said ring unit, and having one end connected to said top shaft portion and the other end connected to said top housing portion of said housing body. 
     
     
         6 . The retractable apparatus as claimed in  claim 5 , wherein said rotating unit further comprises an additional ring unit extending radially outwardly from said rotating shaft to form a ring, and located between said bottom shaft portion and said middle shaft portion. 
     
     
         7 . The retractable apparatus as claimed in  claim 4 , wherein said retractable unit comprises a retractable member, and an engaging member and an operating member respectively disposed on two opposite ends of said retractable member, said retractable member being wound around said middle shaft portion of said rotating shaft, said engaging member being engaged with said middle shaft portion of said rotating shaft so as to interlink said retractable member and said rotating shaft, said operating member being disposed outside of said housing body, and being operable for pulling said retractable member out of said top housing portion of said housing body from said middle shaft portion. 
     
     
         8 . The retractable apparatus as claimed in  claim 1 , wherein said housing teeth set includes a plurality of tooth structures, each of said tooth structures of said housing teeth set including a straight tooth surface that extends in an axial direction, and an inclined tooth surface that extends from an end of said straight tooth surface proximate to said rotating unit in said first turning direction and away from said rotating unit, said shaft teeth set including a plurality of tooth structures, each of said tooth structures of said shaft teeth set including a straight tooth surface that abuts against said straight tooth surface of a respective one of said tooth structures of said housing teeth set, and an inclined tooth surface that abuts against said inclined tooth surface of another one of said tooth structures of said housing teeth set.