how connect 2 object

hi all, how to connect and disconnect the two objects using key.space and hingeJoint

or otherwise

Please help, I have no ideas :(

from other question

how attach 2 object eg. tractor and trailer.

"hingeJoint.connectedBody" not work bcs trailer attach each side

 var otherBody : Rigidbody;
  
 function OnCollisionEnter (collision : Collision) {
     
     if (collision.rigidbody){
         hingeJoint.connectedBody = otherBody;
         
         print("ho");
     }
 }
 function Update () {
     
      if (Input.GetKey(KeyCode.Z)){
     
         hingeJoint.connectedBody = null;
         
         print("hi");
     }
 }