Weight-adjustable dumbbell

Abstract

An improved weight-adjustable dumbbell includes a carrier base, a plurality of weights, and two selection devices. The weights are mounted one by one respectively outside said carrier base, each having a through hole. The two selection devices are mounted respectively at two lateral sides of the carrier base, having an adjusting rod and an adjusting unit. The adjusting rod has a first guidance and a second guidance. The adjusting unit has a rotatable member and a retaining piece. The rotatable member has at least one retaining portion for stopping the rotatable member from axial movement, and a guide lug slidably engaging the guide groove. The retaining piece slidably engages the second guidance for stopping the adjusting rod from axial rotation. When the rotatable member is rotated, the adjusting rod can be driven to axially reciprocate through the through holes of the weights to select the desired number of the weights.

1 . A weight-adjustable dumbbell comprising: 
 a carrier base having two support frames and a handgrip mounted between said two support frames for holding by the user's hand;    a plurality of weights mounted respectively outside said two support frames and interconnected with one another, each of said weights having a through hole; and    two selection devices mounted respectively at bilateral sides of said carrier base and having an adjusting rod and an adjusting unit, said adjusting rod having a first guidance and a second guidance, said adjusting unit having a rotatable member for rotation by a force, and a retaining member engaging against said carrier base for stopping said rotatable member from axial movement, a guide lug slidably engaging said first guidance of said adjusting rod, a retaining piece engaging said second guidance of said adjusting rod for stopping said adjusting rod from rotation, whereby when said rotatable member of said adjusting unit is rotated, said guide lug moves along said first guidance to drive said adjusting rod to axially reciprocate through said through holes of said weights so as to optionally select the number of said weights.    
   
   
       2 . The dumbbell as defined in  claim 1 , wherein each of said weights comprises at least one hook-like coupling portion, by which said weights can be interconnected one by one.  
   
   
       3 . The dumbbell as defined in  claim 1 , wherein said first guidance of said adjusting rod is a guide groove arcuately extending along a periphery of said adjusting rod; said guide lug of said rotatable member of said adjusting unit comprises a distal end slidably engaging said guide groove.  
   
   
       4 . The dumbbell as defined in  claim 1 , wherein said second guidance is a guide channel extending longitudinally along a periphery of said adjusting rod for a predetermined length; said retaining piece slidably engages said guide channel for stopping said adjusting rod from rotation to enable said adjusting rod to axially reciprocate within the predetermined length of the guide channel.  
   
   
       5 . The dumbbell as defined in  claim 1 , wherein said rotatable member is mounted inside said two support frames of said carrier base; said retaining members are mounted at two sides of said rotatable member for engaging inner sides of said two support frames of said carrier base.  
   
   
       6 . The dumbbell as defined in  claim 1 , wherein said rotatable member comprises a locating portion and a plurality of locating recesses annularly arranged on a peripheral edge of said locating portion; said dumbbell further comprises a locating member located beside said locating portion of said rotatable member for detachably engaging one of said locating recesses.  
   
   
       7 . The dumbbell as defined in  claim 6  further comprising an auxiliary locating member, said auxiliary locating member being located beside said locating portion of said rotatable member and having a ball and a springy member, said ball being biased by said springy member for engaging one of said locating recesses of said rotatable member.  
   
   
       8 . The dumbbell as defined in  claim 1 , wherein said guide lug of said rotatable member is spherical.  
   
   
       9 . The dumbbell as defined in  claim 1 , wherein said retaining piece of said adjusting unit is spherical.  
   
   
       10 . A weight-adjustable dumbbell comprising: 
 a carrier base having two support frames and a handgrip mounted between said two support frames for holding by the user's hand;    a plurality of weights mounted respectively outside said two support frames and interconnected with one another, each of said weights having a through hole; and    two selection devices mounted respectively at bilateral sides of said carrier base and having a adjusting rod and an adjusting unit, said adjusting rod having a guide groove and a guide channel, said guide groove arcuately extending along a periphery of said adjusting rod, said guide channel extending longitudinally along the periphery of said adjusting rod for a predetermined length, said adjusting unit having a rotatable member for rotation by a force, a retaining member engaging against inner sides of said support frames of said two said carrier base for stopping said rotatable member from axial movement, a guide lug slidably engaging said guide groove of said adjusting rod, and a retaining piece engaging said guide channel of said adjusting rod for stopping said adjusting rod from rotation, whereby when said rotatable member of said adjusting unit is rotated, said guide lug moves along said guide groove to drive said adjusting rod to axially reciprocate through said through holes of said weights within the predetermined length of said guide channel so as to optionally select the number of said weights.    
   
   
       11 . The dumbbell as defined in  claim 10 , wherein each of said weights comprises at least one hook-like coupling portion, by which said weights can be interconnected one by one.  
   
   
       12 . The dumbbell as defined in  claim 10 , wherein said rotatable member comprises a locating portion and a plurality of locating recesses annularly arranged on a peripheral edge of said locating portion; said dumbbell further comprises a locating member located beside said locating portion of said rotatable member for detachably engaging one of said locating recesses.  
   
   
       13 . The dumbbell as defined in  claim 10  further comprising an auxiliary locating member, said auxiliary locating member being located beside said locating portion of said rotatable member and having a ball and a springy member, said ball being biased by said springy member for engaging one of said locating recesses of said rotatable member.  
   
   
       14 . The dumbbell as defined in  claim 10 , wherein said guide lug of said rotatable member is spherical.  
   
   
       15 . The dumbbell as defined in  claim 10 , wherein said retaining piece of said adjusting unit is spherical.