Self-locking joint for an expanding-tighten type shelf

Abstract

A self-locking joint for an expanding-tighten type shelf includes a supporting plate ( 1 ) as a U-shaped slot and a plastic supporting block ( 2 ) inserted in the U-shaped slot. In the slot there are concave-convex self-locking device ( 3 ) at two sides of the slot for preventing the supporting block from detaching. The U-shaped slot accepting the plastic-supporting block is applied in the structure. The shelf is secured elastically on the column of the frame due to the elasticity of the supporting block. In the invention it is convenient to assembly or dismantle the shelf without a special tool. The structure could be self-locked tightly and could not be loosen easily.

1 . A self-locking joint for an expanding-tighten type shelf comprising:
 a supporting plate forming a U-shaped slot;   a plastic supporting block inserted in the U-shaped slot and having a concave surface for matching with the shape of the post of the shelf; and   a concave-convex self-locking device at two sides of the U-shaped slot for preventing the supporting block from detaching, the concave-convex self-locking device being of a distance from the bottom of the U-shaped slot;   wherein the concave-convex self-locking device comprises elastic locking pieces respectively protruded from the two sides of the U-shaped slot and inclined towards the bottom of the U-shaped slot, each of the elastic locking pieces has a free end having a distance from the bottom of the U-shaped slot, recesses corresponding to the positions of the elastic locking pieces are provided respectively on the two sides of the plastic supporting block, the recess is of a size adapted to be completely contained in the elastic locking piece, and the free end of the elastic locking piece leans on the bottom of the recess to lock the plastic supporting block when the plastic supporting block is inserted in the U-shaped slot.   
   
   
       2 . The self-locking joint of  claim 1 , wherein the recess of the plastic supporting block is a L-shaped recess with a bottom ending at a position corresponding to the free end of the elastic locking piece. 
   
   
       3 . The self-locking joint of  claim 1 , wherein the recess of the plastic supporting block is an acute angle-shaped recess with a bottom ending at a position corresponding to the free end of the elastic locking piece. 
   
   
       4 . The self-locking joint of  claim 1 , wherein a self-locking protrusion is provided on the concave surface of the plastic supporting block. 
   
   
       5 . The self-locking joint of  claim 1 , wherein hems for retaining the plastic supporting block are provided respectively on the two ends of the U-shaped slot. 
   
   
       6 . A self-locking joint for an expanding-tighten type shelf, comprising:
 a supporting plate forming a U-shaped slot;   a plastic supporting block inserted in the U-shaped slot and having a concave surface for matching with the shape of the post of the shelf; and   a concave-convex self-locking device at two sides of the U-shaped slot for preventing the supporting block from detaching, the concave-convex self-locking device being of a distance from the bottom of the U-shaped slot;   wherein the concave-convex self-locking device comprises through holes respectively on the two sides of the U-shaped slot, each of the through holes is of a distance from the bottom of the U-shaped slot, wedge-shaped protrusions corresponding to the positions of the through holes are provided respectively on the two sides of the plastic supporting block, the wedge-shaped protrusion is of an expanded surface in the direction of pressing the protrusion into the U-shaped slot and a size adapted to be completely contained in the through holes, and the wedge-shaped protrusion is clasped in the through hole to lock the plastic supporting block when the plastic supporting block is inserted in the U-shaped slot.   
   
   
       7 . The self-locking joint of  claim 6 , wherein the wedge-shaped protrusion is ball crown-shaped. 
   
   
       8 . The self-locking joint of  claim 6 , wherein the wedge-shaped protrusion is inverted triangle-shaped. 
   
   
       9 . The self-locking joint of  claim 6 , wherein a self-locking protrusion is provided on the concave surface of the plastic supporting block. 
   
   
       10 . The self-locking joint of  claim 6 , wherein hems for retaining the plastic supporting block are provided respectively on the two ends of the U-shaped slot. 
   
   
       11 . A self-locking joint for an expanding-tighten type shelf, comprising:
 a supporting plate forming a U-shaped slot;   a plastic supporting block inserted in the U-shaped slot and having a concave surface for matching with the shape of the post of the shelf; and   a concave-convex self-locking device at two sides of the U-shaped slot for preventing the supporting block from detaching, the concave-convex self-locking device being of a distance from the bottom of the U-shaped slot;   wherein the concave-convex self-locking device comprises recesses respectively on the two sides of the U-shaped slot, each of the recesses is of a distance from the bottom of the U-shaped slot, wedge-shaped protrusions corresponding to the positions of the recesses are provided respectively on the two sides of the plastic supporting block, the wedge-shaped protrusion is of an expanded surface in the direction of pressing the protrusion into the U-shaped slot and a size adapted to be completely contained in the recess, and the wedge-shaped protrusion is clasped in the recess to lock the plastic supporting block when the plastic supporting block is inserted in the U-shaped slot.   
   
   
       12 . The self-locking joint of  claim 11 , wherein the wedge-shaped protrusion is ball crown-shaped. 
   
   
       13 . The self-locking joint of  claim 11 , wherein the wedge-shaped protrusion is inverted triangle-shaped. 
   
   
       14 . The self-locking joint of  claim 11 , wherein a self-locking protrusion is provided on the concave surface of the plastic supporting block. 
   
   
       15 . The self-locking joint of  claim 11 , wherein hems for retaining the plastic supporting block are provided respectively on the two ends of the U-shaped slot.