Adjustable dumbbell system

Abstract

A handle has opposed ends and a central extent. A grip rotationally receives the central extent of the handle. An adjustment wheel is secured to each end of the handle. A side cover is fixedly secured to each end of the grip. A dowel disk is on the handle adjacent to one side cover with fingers and spaces. A plurality of cam bits are supported on the handle. A safety lock is within the side cover adjacent to the dowel disk. The safety lock has a first end extent and a second end extent with a radial recess and a central extent with an axial projection. A coil spring within the radial recess urges the safety lock radially outwardly. A safety indicator may be seen on one side cover that changes from red to green as the weight selection wheel is turned, indication proper weight selection when green and a potential unsafe condition when red.

What is claimed is: 
     
         1 . An adjustable dumbbell system comprising:
 a dumbbell having a handle having opposed ends and a central extent, a grip rotationally receiving the central extent of the handle, an adjustment wheel secured to each end of the handle, a side cover fixedly secured to each end of the grip, a dowel disk on the handle adjacent to each side cover with fingers and spaces,   a plurality of cam bits supported on the handle;   a safety lock within a first one of the side covers adjacent to the dowel disk, the safety lock having a first end extent and a second end extent with a radial recess and a central extent with an axial projection, a coil spring within the radial recess urging the safety lock radially outwardly; and   a pivot indicator within a second one of the side covers adjacent to the dowel disk, the safety indicator being viewable through a window in the second one of the side covers, the safety indicator having an extension fitting into the spaces of the dowel disk to show a safe condition and the extension causing the pivot indicator to pivot to show an unsafe condition through the window as the adjustment wheel is turned.   
     
     
         2 . The system as set forth in  claim 1  wherein the safety lock is movable between a raised locked orientation and a lowered unlocked orientation, the safety lock when in the raised locked orientation positioning the axial projection in a space between adjacent fingers of the dowel disk for allowing only limited rotation of the dowel disk, cam bits, handle and adjustment disks with respect to the side covers, safety lock and grip whereby the user may not change the weight to be lifted with the lifting of the dumbbell, the safety lock when in the lowered unlocked orientation positioning the axial projection radially spaced from the fingers and spaces of the dowel disk for allowing full rotation between the dowel disk, cam bits, handle and adjustment disks with respect to the side covers, safety lock and grip whereby the user may change the weight to be lifted with the lifting of the dumbbell. 
     
     
         3 . The system as set forth in  claim 1  wherein each finger has a width of about 5 mm, each space has a width of about 8 mm and the central extent has a width of about 4.5 mm. 
     
     
         4 . The system as set forth in  claim 1  wherein the width of the central extent has a width of between 50 and 60 percent of the space between adjacent fingers. 
     
     
         5 . The system as set forth in  claim 1  and further including:
 a plurality of weights, one weight for each cam bit, each weight having openings and each cam bit having a cam surface whereby the weights are adapted to attach to and release from an associated cam bit as a function of the rotational orientation of the shaft and adjustment wheels, each weight having a central primary aperture and primary slot, each weight having a major section and an axially offset secondary minor section, the minor section being formed with a secondary aperture and a secondary slot and wherein each cam plate includes an irregularly shaped polygon with radially enlarged sections providing cam surfaces at maximum radii greater than the radii of the remainder of the cam plate, the radially enlarged sections adapted to releasably couple selectively with the secondary aperture of the weights. 
 
     
     
         6 . The system as set forth in  claim 5  and further including:
 a base for receiving a dumbbell with its weights, the base including an upstanding vertical component for moving the safety lock between the locked orientation and the unlocked orientation. 
 
     
     
         7 . The system as set forth in  claim 6  and further including:
 a laterally extending horizontal component for locking the dumbbell to the base when the safety lock in not vertically aligned with a space between fingers of the dowel disk. 
 
     
     
         8 . The system as set forth in  claim 1 , wherein the safe condition is indicated by a green color viewable through the window and the unsafe condition is indicated by a red color viewable through the window. 
     
     
         9 . The system as set forth in  claim 1 , wherein the unsafe condition occurs when the extension is angled against one of the fingers of the dowel disk. 
     
     
         10 . An adjustable dumbbell system for selectively varying the weight to be lifted by a user, such selective varying being done in a safe, convenient and economical manner, the system comprising, in combination:
 a dumbbell having a handle in a cylindrical configuration with.a central axis, the handle having opposed ends and a central extent, a tubular grip with opposed ends rotationally receiving the central extent of the handle, an adjustment wheel secured to each end of the handle for rotating the handle with respect to the grip, a side cover fixedly secured to each end of the grip, a dowel disk rotatably supported on the handle adjacent to each side cover, the dowel disk having radially extending fingers each about  5  rom in width equally spaced from the central axis with spaces each about  8  mm in width between the fingers, a plurality of cam bits supported on the handle between the side covers and the adjustment wheels, the cam bits being secured on each side of the side covers for concurrent rotation with the handle;   a plurality of weights, one weight for each cam bit, each weight having openings and each cam bit having a cam surface whereby the weights are adapted to attach to and release from an associated cam bit as a function of the rotational orientation of the shaft and adjustment wheels, each weight having a central primary aperture and primary slot, each weight having a major section and an axially offset secondary minor section, the minor section being formed with a secondary aperture and a secondary slot and wherein each cam plate includes an irregularly shaped polygon with radially enlarged sections providing cam surfaces at maximum radii greater than the radii of the remainder of the cam plate, the radially enlarged sections adapted to releasably couple selectively with the secondary aperture of the weights;   a safety lock radially positioned for reciprocable movement within a first one of the side covers adjacent to the dowel disk, the safety lock having an upper extent with an exposed button and a lower extent with a radial recess and a central extent with an axial projection, the axial projection being about 4.5 rom in width, a coil spring within the radial recess urging the safety lock upwardly and radially outwardly, the safety lock movable between a raised locked orientation and a lowered unlocked orientation, the safety lock when in the raised locked orientation positioning the axial projection in a space between adjacent fingers of the dowel disk for allowing only limited rotation of the dowel disk, cam bits, handle and adjustment disks with respect to the side covers, safety lock and grip whereby the user may not change the weight to be lifted with the lifting of the dumbbell, the safety lock when in the lowered unlocked orientation positioning the axial projection radially spaced from the fingers and spaces of the dowel disk for allowing full rotation between the dowel disk, cam bits, handle and adjustment disks with respect to the side covers, safety lock and grip whereby the user may change the weight ,to be lifted with the lifting of the dumbbell; and   a pivot indicator within a second one of the side covers adjacent to the dowel disk, the safety indicator being viewable through a window in the second one of the side covers, the safety indicator having an extension fitting into the spaces of the dowel disk to show a safe condition and the extension causing the pivot indicator to pivot to show an unsafe condition through the window as the adjustment wheel is turned   
     
     
         11 . The system as set forth in  claim 10 , wherein the safe condition is indicated by a green color viewable through the window and the unsafe condition is indicated by a red color viewable through the window. 
     
     
         12 . The system as set forth in  claim 10 , wherein the unsafe condition occurs when the extension is angled against one of the fingers of the dowel disk.