Adjustable Dumbbell

Abstract

The present disclosure relates to an adjustable dumbbell, comprising a base, symmetrical weight assemblies, and a dumbbell bar. The base is provided with a mounting seat and a weight holder. The weight assembly is formed by stacking a plurality of weight plates, featuring a unique design of a wider top ad a narrower bottom with complementary embedding grooves and embedded blocks, greatly simplifying assembly and preventing lateral separation. The dumbbell bar is rotated to drive a spindle to extend or retract along a helical groove through rotation, achieving rapid locking and release of the weight plates.

What is claimed is: 
     
         1 . An adjustable dumbbell, comprising:
 a dumbbell bar internally provided with an axially extending guide rail;   connection seats arranged at both ends of the dumbbell bar, each provided with a mounting hole at a center thereof;   a weight assembly comprising a plurality of stacked weight units, wherein each weight unit is provided with a through hole, and a detachable lateral interlocking structure is arranged between adjacent weight units to restrict a horizontal relative displacement between the adjacent weight units;   a spindle laterally slidably arranged inside the dumbbell bar and extending into the mounting holes of the connection seats, wherein an outer surface of the spindle is provided with a helical groove and an axially extending guide groove; and   a spline arranged inside the connection seat, wherein the spline is provided with a boss extending into the helical groove, and the boss presents a helical shape matching the helical groove;   wherein the guide rail inside the dumbbell bar is slidably fitted with the guide groove of the spindle to directly transmit a rotational motion of the dumbbell bar to the spindle, thereby achieving synchronous rotation of the dumbbell bar and the spindle; and   wherein when the spindle is rotated, the boss slides along the helical groove, converting a rotational motion of the spindle into an axial movement; and   wherein when the spindle is extended axially, a tail end thereof penetrates the connection seats and the through hole of at least one weight unit, forming a longitudinal constraint on the weight unit, allowing the weight assembly to be fixedly connected to the connection seats; and   wherein when the spindle is retracted axially, the tail end thereof withdraws from the through hole, releasing the longitudinal constraint, allowing the weight assembly to be separated from the connection seats.   
     
     
         2 . The adjustable dumbbell according to  claim 1 , wherein the connection seats are rotatably connected to both ends of the dumbbell bar, and the mounting holes are coaxial with the through holes. 
     
     
         3 . The adjustable dumbbell according to  claim 1 , wherein the spline is provided with a central hole at a center thereof, and the boss is arranged on an inner wall of the central hole. 
     
     
         4 . The adjustable dumbbell according to  claim 1 , wherein the connection seat comprises a side plate with a first penetrating hole and a cover with a second penetrating hole; one side of the side plate is slidably connected to the weight assembly, and the cover is placed on the other side of the side plate and is fitted with the side plate to form an accommodating cavity; the mounting hole is formed by fitting of the first penetrating hole and the second penetrating hole, an end of the dumbbell bar passes through the second penetrating hole and extends into the accommodating cavity, and the spline is arranged at the first penetrating hole. 
     
     
         5 . The adjustable dumbbell according to  claim 4 , wherein two clamping plates symmetrically arranged relative to the first penetrating hole are fixed on a side of the side plate facing the spline, and a clamping groove adapted to the spline is formed between the two clamping plates and the first penetrating hole, wherein the spline is engaged and fitted with the clamping groove. 
     
     
         6 . The adjustable dumbbell according to  claim 5 , wherein a positioning groove is provided on one side of the spline, a washer is arranged in the first penetrating hole, one side of the washer extends into the clamping groove and extends radially outward to form a flange, wherein the flange abuts against a groove bottom of the positioning groove, and an inner diameter of the washer matches that of the spline. 
     
     
         7 . The adjustable dumbbell according to  claim 1 , wherein the weight unit is a weight plate, and two adjacent weight plates are longitudinally slidably fitted; a plurality of weight plates comprise an inner plate, several intermediate plates, and an outer plate, with one side of the inner plate contacting the connection seat. 
     
     
         8 . The adjustable dumbbell according to  claim 7 , wherein the lateral interlocking structure comprises first embedding grooves and first embedded blocks arranged on both sides of the inner plate, both sides of the intermediate plates, and a side of the outer plate facing the intermediate plates, wherein two adjacent weight plates are interconnected through a complementary structure of the first embedding grooves and first embedded blocks; and
 a surface of the connection seat away from the dumbbell bar is provided with a second embedding groove and a second embedded block, the first embedding groove on a side of the inner plate away from the intermediate plate is fitted with the second embedded block, and the first embedded block on the side of the inner plate away from the intermediate plate is configured for fitting with the second embedding groove.   
     
     
         9 . An adjustable dumbbell, comprising:
 a dumbbell bar;   connection seats arranged at both ends of the dumbbell bar, each provided with a mounting hole at a center thereof;   a weight assembly comprising a plurality of stacked weight units, wherein each weight unit is provided with a through hole, and a detachable lateral interlocking structure is arranged between adjacent weight units to restrict a horizontal relative displacement between the adjacent weight units;   a spindle laterally slidably arranged inside the dumbbell bar and extending into the mounting holes of the connection seats, wherein an outer surface of the spindle is provided with a helical groove;   a spline arranged inside the connection seat, wherein the spline is provided with a boss extending into the helical groove, and the boss presents a helical shape matching the helical groove; and   a rotational transmission assembly that is arranged between the dumbbell bar and the spindle and is configured to transmit a rotational motion of the dumbbell bar to the spindle, achieving synchronous rotation of the dumbbell bar and the spindle while allowing the spindle to slide axially relative to the dumbbell bar;   wherein when the spindle is rotated, the boss slides along the helical groove, converting the rotational motion of the spindle into axial movement; and   wherein when the spindle is extended axially, a tail end thereof penetrates the connection seats and the through hole of at least one weight unit, forming a longitudinal constraint on the weight unit, allowing the weight assembly to be fixedly connected to the connection seats; and   wherein when the spindle is retracted axially, the tail end thereof withdraws from the through hole, releasing the longitudinal constraint, allowing the weight assembly to be separated from the connection seats.   
     
     
         10 . The adjustable dumbbell according to  claim 9 , wherein the rotational transmission assembly comprises a guide groove arranged on the spindle, and the dumbbell bar is provided with a guide rail that is slidably fitted with the guide groove; and
 the guide rail inside the dumbbell bar is slidably fitted with the guide groove of the spindle to directly transmit a rotational motion of the dumbbell bar to the spindle, thereby achieving synchronous rotation of the dumbbell bar and the spindle.   
     
     
         11 . The adjustable dumbbell according to  claim 9 , wherein the connection seat comprises a side plate with a first penetrating hole and a cover with a second penetrating hole; one side of the side plate is slidably connected to the weight assembly, and the cover is placed on the other side of the side plate and is fitted with the side plate to form an accommodating cavity; the mounting hole is formed by fitting of the first penetrating hole and the second penetrating hole, an end of the dumbbell bar passes through the second penetrating hole and extends into the accommodating cavity, and the spline is arranged at the first penetrating hole. 
     
     
         12 . The adjustable dumbbell according to  claim 9 , wherein the weight unit is a weight plate, and two adjacent weight plates are longitudinally slidably connected; a plurality of weight plates comprise an inner plate, several intermediate plates, and an outer plate, with one side of the inner plate contacting the connection seat. 
     
     
         13 . The adjustable dumbbell according to  claim 12 , wherein the lateral interlocking structure comprises first embedding grooves and first embedded blocks arranged on both sides of the inner plate, both sides of the intermediate plates, and a side of the outer plate facing the intermediate plates, wherein two adjacent weight plates are interconnected through a complementary structure of the first embedding grooves and first embedded blocks; and
 a surface of the connection seat away from the dumbbell bar is provided with a second embedding groove and a second embedded block, the first embedding groove on a side of the inner plate away from the intermediate plate is fitted with the second embedded block, and the first embedded block on the side of the inner plate away from the intermediate plate is configured for fitting with the second embedding groove.   
     
     
         14 . An adjustable dumbbell, comprising:
 a dumbbell bar;   connection seats arranged at both ends of the dumbbell bar, each provided with a mounting hole at a center thereof;   a weight assembly comprising a plurality of stacked weight units, wherein each weight unit is provided with a through hole, and a detachable lateral interlocking structure is arranged between adjacent weight units to restrict a horizontal relative displacement between the adjacent weight units;   a spindle laterally slidably arranged inside the dumbbell bar and extending into the mounting holes of the connection seats;   a rotational transmission assembly that is arranged between the dumbbell bar and the spindle and is configured to transmit a rotational motion of the dumbbell bar to the spindle, achieving synchronous rotation of the dumbbell bar and the spindle while allowing the spindle to slide axially relative to the dumbbell bar; and   an axial conversion assembly that is arranged between the spindle and the connection seat and converts a rotational motion of the spindle into an axial movement of the spindle when the spindle is rotated;   wherein when the spindle is extended axially, a tail end thereof penetrates the connection seats and the through hole of at least one weight unit, forming a longitudinal constraint on the weight unit, allowing the weight assembly to be fixedly connected to the connection seats; and   wherein when the spindle is retracted axially, the tail end thereof withdraws from the through hole, releasing the longitudinal constraint, allowing the weight assembly to be separated from the connection seats.   
     
     
         15 . The adjustable dumbbell according to  claim 14 , wherein the axial conversion assembly comprises a helical groove provided on an outer surface of the spindle; and
 a spline arranged within the connection seat, wherein the spline is provided with a boss extending into the helical groove, and the boss presents a helical shape matching the helical groove;   wherein when the spindle is rotated, the boss slides along the helical groove, converting the rotational motion of the spindle into an axial movement.   
     
     
         16 . The adjustable dumbbell according to  claim 15 , wherein the spline is provided with a central hole at a center thereof, and the boss is arranged on an inner wall of the central hole. 
     
     
         17 . The adjustable dumbbell according to  claim 15 , wherein the connection seat comprises a side plate with a first penetrating hole and a cover with a second penetrating hole; one side of the side plate is slidably connected to the weight assembly, and the cover is placed on the other side of the side plate and is fitted with the side plate to form an accommodating cavity; the mounting hole is formed by fitting of the first penetrating hole and the second penetrating hole, an end of the dumbbell bar passes through the second penetrating hole and extends into the accommodating cavity, and the spline is arranged at the first penetrating hole. 
     
     
         18 . The adjustable dumbbell according to  claim 17 , wherein two clamping plates symmetrically arranged relative to the first penetrating hole are fixed on a side of the side plate facing the spline, and a clamping groove adapted to the spline is formed between the two clamping plates and the first penetrating hole, wherein the spline is engaged and fitted with the clamping groove. 
     
     
         19 . The adjustable dumbbell according to  claim 14 , wherein the weight unit is a weight plate, and two adjacent weight plates are longitudinally slidably fitted; a plurality of weight plates comprise an inner plate, several intermediate plates, and an outer plate, with one side of the inner plate contacting the connection seat. 
     
     
         20 . The adjustable dumbbell according to  claim 19 , wherein the lateral interlocking structure comprises first embedding grooves and first embedded blocks arranged on both sides of the inner plate, both sides of the intermediate plates, and a side of the outer plate facing the intermediate plates, wherein two adjacent weight plates are interconnected through a complementary structure of the first embedding grooves and first embedded blocks; and
 a surface of the connection seat away from the dumbbell bar is provided with a second embedding groove and a second embedded block, the first embedding groove on a side of the inner plate away from the intermediate plate is fitted with the second embedded block, and the first embedded block on the side of the inner plate away from the intermediate plate is configured for fitting with the second embedding groove.