Adjustable-barrel curling iron

Abstract

A radially adjustable barrel, a barrel-adjustment assembly, a radially adjustable heater assembly, and a radially adjustable distal-tip assembly. The barrel is radially adjustable between expanded and contracted positions having different diameters. The barrel-adjustment assembly includes a rotary ring defining a spiral cam guide and includes a cam follower attached to the barrel. The heater assembly includes a post, at least one heater, and at least one spring mounting the heater to the post and biasing the heater radially outward. In use, rotating the ring rotates the spiral cam guide, which displaces the cam follower radially inward or outward, which in turn displaces the outer end of the barrel radially inward or outward to decrease or increase the diameter of the barrel. As the diameter of the barrel is adjusted, the heaters remain in contact with the barrel due to the outwardly biasing influence of the spring.

1 . An adjustable-barrel curling iron, comprising:
 a handle;   a pivotal clip mounted to the handle;   a radially-adjustable barrel extending longitudinally from the handle, having an outer end and an inner end that overlap each other in a spiral configuration, and radially adjustable between expanded and contracted positions having different diameters;   a heater assembly that provides heat to the barrel; and   a barrel-adjustment assembly including a rotary ring that defines a spiral cam guide and a cam follower extending from the barrel and driven by the spiral cam guide, wherein the rotating the ring relative to the handle rotates the spiral cam guide, which displaces the cam follower radially inward or outward, which in turn displaces the outer end of the barrel radially inward or outward to adjust the barrel between the expanded and contracted positions.   
     
     
         2 . The adjustable-barrel curling iron of  claim 1 , wherein the spiral shape of the cam guide is selected so that the barrel is concentric at every position as the cam follower is guided radially inward and outward by the spiral cam guide. 
     
     
         3 . The adjustable-barrel curling iron of  claim 1 , wherein the spiral cam guide is formed by a spiral groove in the rotary ring and the cam follower is formed by an elongate clip attached to the barrel. 
     
     
         4 . The adjustable-barrel curling iron of  claim 3 , wherein the cam follower has an enlarged head and the spiral cam guide groove has an enlarged portion through which the enlarged head fits, and wherein the enlarged head does not fit through the rest of the spiral cam guide groove. 
     
     
         5 . The adjustable-barrel curling iron of  claim 1 , wherein the rotary ring includes a collar for user grasping and rotation. 
     
     
         6 . The adjustable-barrel curling iron of  claim 1 , wherein the heater assembly is radially adjustable and includes a central rotary post, at least one heater, and at least one spring mounted between the heater and the post. 
     
     
         7 . The adjustable-barrel curling iron of  claim 6 , wherein the spring biases the heater radially outward so that, as the diameter of the barrel is adjusted, the heater remains in contact with the barrel. 
     
     
         8 . The adjustable-barrel curling iron of  claim 6 , wherein the spring includes a clip that couples the heater to the spring. 
     
     
         9 . The adjustable-barrel curling iron of  claim 6 , wherein the at least one heater comprises three heaters and the central post has three sides and a triangular cross section, with each one of the heaters mounted to a corresponding one of the sides. 
     
     
         10 . The adjustable-barrel curling iron of  claim 6 , wherein the central post is coupled to and rotationally driven by the rotary ring. 
     
     
         11 . The adjustable-barrel curling iron of  claim 10 , wherein rotary ring has an opening through which the central post extends, and wherein the ring opening and the central post have confirming geometry so that rotating the rotary ring causes the post to rotate with it. 
     
     
         12 . The adjustable-barrel curling iron of  claim 6 , wherein the handle includes a fixed ring that is adjacent the rotary ring and has an opening through which the central post extends freely without constraint, the post includes a stopper, and the handle defines a cradle that receives the post and abuts the stopper to constrain the post from linear movement while still permitting its free-floating rotational movement. 
     
     
         13 . An adjustable-barrel curling iron, comprising:
 a handle;   a pivotal clip mounted to the handle;   a radially-adjustable barrel extending longitudinally from the handle, having an outer end and an inner end that overlap each other in a spiral configuration, and radially adjustable between expanded and contracted positions having different diameters;   a radially adjustable heater assembly that provides heat to the barrel and that includes a central rotary post, at least one heater, and at least one spring mounted between the heater and the post, wherein the central post is rotationally driven by the rotary ring, and wherein the spring biases the heater radially outward; and   a barrel-adjustment assembly including a rotary ring that defines a spiral cam guide and a cam follower extending from a proximal end of the barrel and driven by the spiral cam guide, wherein the spiral cam guide is formed by a spiral groove in the rotary ring and the cam follower is formed by an elongate clip attached to the barrel, wherein the rotating the ring relative to the handle rotates the spiral cam guide, which displaces the cam follower radially inward or outward, which in turn displaces the outer end of the barrel radially inward or outward to adjust the barrel between the expanded and contracted positions, wherein the spiral shape of the cam guide is selected so that the barrel is concentric at every position as the cam follower is guided radially inward and outward by the spiral cam guide, wherein as the diameter of the barrel is adjusted, the heater remains in contact with the barrel due to the spring biasing the heater radially outward.   
     
     
         14 . The adjustable-barrel curling iron of  claim 13 , wherein the cam follower has an enlarged head and the spiral cam guide groove has an enlarged portion through which the enlarged head fits, and wherein the enlarged head does not fit through the rest of the spiral cam guide groove. 
     
     
         15 . The adjustable-barrel curling iron of  claim 13 , wherein the rotary ring includes a collar for user grasping and rotation. 
     
     
         16 . The adjustable-barrel curling iron of  claim 13 , wherein the spring includes a clip that couples the heater to the spring. 
     
     
         17 . The adjustable-barrel curling iron of  claim 13 , wherein the at least one heater comprises three heaters and the central post has three sides and a triangular cross section, with each one of the heaters mounted to a corresponding one of the sides. 
     
     
         18 . The adjustable-barrel curling iron of  claim 13 , wherein rotary ring has an opening through which the central post extends, and wherein the ring opening and the central post have confirming geometry so that rotating the rotary ring causes the post to rotate with it. 
     
     
         19 . The adjustable-barrel curling iron of  claim 13 , wherein the handle includes a fixed ring that is adjacent the rotary ring and has an opening through which the central post extends freely without constraint, the post includes a stopper, and the handle defines a cradle that receives the post and abuts the stopper to constrain the post from linear movement while still permitting its free-floating rotational movement. 
     
     
         20 . The adjustable-barrel curling iron of  claim 13 , further comprising a cam follower extending from a distal end of the barrel and a distal-tip assembly defining a spiral cam guide that cooperates with the cam follower and that conforms to the configuration of the spiral cam guide of the rotary ring, except that it is reversed, so that rotation of the rotary collar causes the proximal and distal ends of the barrel to be rotated synchronously.