Ring diameter variator for ring-shaped accessory

Abstract

A ring diameter variator for a ring-shaped accessory includes a case that has first and second pull-out ports in opposite end parts, a reel that is rotatably housed within the case, first and second adjustment straps that are each wound up in the same direction by the reel and pulled outward through the first and second pull-out ports and that are connected to one end and the other end of the ring-shaped accessory, and a spiral spring that rotatingly urges the reel in a wind-up direction of the first and second adjustment straps. Thus, it is possible to provide a ring diameter variator for a ring-shaped accessory that enables sufficient enlargement of ring diameter and that has a good appearance.

1 . A ring diameter variator for a ring-shaped accessory that is connected between one end and the other end of the ring-shaped accessory to make the ring diameter of the ring-shaped accessory variable,
 wherein the variator comprises a case that has first and second pull-out ports in opposite end parts, a reel that is rotatably housed within the case, first and second adjustment straps that are each wound up in the same direction by the reel and pulled outward through the first and second pull-out ports and that are connected to one end and the other end of the ring-shaped accessory, and a spiral spring that rotatingly urges the reel in a wind-up direction of the first and second adjustment straps.   
     
     
         2 . The ring diameter variator for a ring-shaped accessory according to  claim 1 , wherein
 the spiral spring is housed in a cylindrical spring chamber formed in an interior of the reel.   
     
     
         3 . The ring diameter variator for a ring-shaped accessory according to  claim 2 , wherein
 a fixed shaft extending through the spring chamber is fixedly supported on the case, a flat face is formed on one side of the fixed shaft, a slit opens on the flat face, an inner end portion of the spiral spring is bent in the radially inward direction while being rounded and is engaged with the slit, and a rounded bent portion of the inner end portion is disposed in a crescent-shaped space formed between the flat face and an inner peripheral face of the spiral spring wound around the fixed shaft.   
     
     
         4 . The ring diameter variator for a ring-shaped accessory according to  claim 1 , wherein
 first and second cutouts are provided in first and second reel flanges provided at opposite ends of the reel, first and second channels communicating with the first and second cutouts are formed in outer end faces of the first and second reel flanges, and inner end portions of the first and second adjustment straps are run respectively through the first and second cutouts, housed in the first and second channels, and adhered thereto.   
     
     
         5 . The ring diameter variator for a ring-shaped accessory according to  claim 2 , wherein
 first and second cutouts are provided in first and second reel flanges provided at opposite ends of the reel, first and second channels communicating with the first and second cutouts are formed in outer end faces of the first and second reel flanges, and inner end portions of the first and second adjustment straps are run respectively through the first and second cutouts, housed in the first and second channels, and adhered thereto.   
     
     
         6 . The ring diameter variator for a ring-shaped accessory according to  claim 3 , wherein
 first and second cutouts are provided in first and second reel flanges provided at opposite ends of the reel, first and second channels communicating with the first and second cutouts are formed in outer end faces of the first and second reel flanges, and inner end portions of the first and second adjustment straps are run respectively through the first and second cutouts, housed in the first and second channels, and adhered thereto.