This creates a kind of automatic telescopic dog's leash safety switching apparatus structural improvement,Using the locating rod on position-sensing switch,Locating channel is cooperated to form two half shell inner face of what,And the design of locating rod on position-sensing switch is corresponded to,Change the positioning method of position-sensing switch,The position-sensing switch positions Hou,It switchs lower section and is limited the limit retaining wall that hole is mounted in what,It can not move left and right,The pulling force 50 or more percent of entire position-sensing switch receiving can be significantly increased,And be preferably minimized position-sensing switch by the reaction force of ratchet block,Improvement, which is commonly used, directly plugs locating rod design disadvantage on position-sensing switch,And ratchet block position-sensing switch Hou generates reaction force on reel,Improve and generate dog-ear phenomenon in locating rod what guide groove,Or because being used for a long time Hou,It horizontally slips on locating rod what position-sensing switch,Cause the depth of left and right locating rod insertion guide groove unequal,Make that the button of position-sensing switch can not position and locating rod is easily damaged problem,This creation can adjust pet frenulum length using position-sensing switch at any time,So that frenulum moderate length is not mopped floor, to be infected with soil dirty,Practicability and the safety of positioning switch device structure is effectively promoted.本創作一種自動伸縮狗鏈安全開關裝置結構改良，其利用定位開關上的定位桿，配合定位導槽形成於兩半殼體內面，並對應定位開關上定位桿之設計，改變定位開關的定位方式，該定位開關定位後，開關下段受限於限位安裝孔之限位擋壁，無法左右移動，可大幅增加整個定位開關承受之拉力百分之五十以上，並將定位開關受棘齒擋止之反作用力降到最低，改良習用定位開關上直接插設定位桿設計缺點，及捲盤上棘齒擋止定位開關後產生反作用力，改善定位桿於導槽內產生折角現象，或因長久使用後，定位桿於定位開關上左右滑動，造成左右定位桿插入導槽的深度不平均，使定位開關之按鈕無法定位及定位桿容易損壞問題，本創作可隨時利用定位開關調整寵物繫帶長度，使繫帶長度適中不會拖地沾染泥土髒汙，有效地提升了定位開關裝置結構的實用性及安全性。
