Safety lock device for quick coupler

Abstract

The present invention relates to a safety lock device for a quick coupler which prevents the coupled state of a work tool installed on a quick coupler at the front of an excavator from becoming arbitrarily released. A safety lock device for a quick coupler according to the present invention is a quick coupler having: a body; a fixed hook formed on one side of the body and having a coupling pin of a work tool inserted therein; and a movable hook provided on a side facing the fixed hook and pivoting according to the actuation of a cylinder to lock another coupling pin of the work tool. Safety locking means are provided on the inside of the body so that the movable hook and the coupling pin of the work tool located within the movable hook are not arbitrarily separated due to the pivoting of the movable hook, firmly maintain a locked state even when a cylinder is damaged during work or transit while the work tool is coupled to the quick coupler, and prevent the work tool from becoming separated or falling from the quick coupler. Thus, accidents causing human casualties and damage to machinery can be prevented, and safety can be ensured.

1 . A safety lock device for a quick coupler, comprising:
 a quick coupler which comprises:   a body;   a fixed hook which is provided at a portion of the body, wherein an coupling pin of a work tool is inserted into the fixed hook; and   a movable hook which is provided at the opposite of the fixed hook and is configured to rotate by the actuation of a cylinder and lock another coupling pin of the work tool, wherein the quick coupler further comprises:   a safety locking means which is provided at an inside of the body and is configured to carry out a locking operation in order for the coupling pin of the work tool, which is located within the movable hook and the fixed hook, not to arbitrarily separate as the movable hook rotates.   
     
     
         2 . The device of  claim 1 , wherein the safety lock means comprises:
 a moving-side hitch which is coupled rotatable at an upper portion of the movable hook and is configured to receive an elastic force from a spring;   a fixing-side hitch which is coupled rotatable at an upper portion of the fixed hook;   an operation bar which is coupled to a front end of the fixing-side hitch and is transferred by the rotation of the movable hook; and   an operation link which is coupled to the moving-side hitch and the fixing-side hitch.   
     
     
         3 . The device of  claim 2 , wherein the operation bar is configured to be transferred within a guide block fixed at the body since a contact part of the movable hook, which rotates by the operation of the cylinder, pushes a front end thereof, whereby the fixing-side hitch can rotate. 
     
     
         4 . The device of  claim 2 , wherein an operation roller, which contacts with the contact part of the movable hook, is provided at a front end of the operation bar. 
     
     
         5 . The device of  claim 2 , wherein the operation link comprises:
 a first link and a second link, an end of each of which is connected to the moving-side hitch and the fixing-side hitch, respectively; and   a both-side threaded nut which is engaged to a front end of each of the first and second links.