// Disable the spring on all HingeJoints
// in this game object and all its child game objects
var hingeJoints : HingeJoint[];
hingeJoints = gameObject.GetComponentsInChildren(HingeJoint);
for (var joint : HingeJoint in hingeJoints) {
joint.useSpring = false;
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
public HingeJoint[] hingeJoints;
void Awake() {
hingeJoints = gameObject.GetComponentsInChildren<HingeJoint>();
foreach (HingeJoint joint in hingeJoints) {
joint.useSpring = false;
}
}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

public hingeJoints as (HingeJoint)

def Awake():
hingeJoints = gameObject.GetComponentsInChildren[of HingeJoint]()
for joint as HingeJoint in hingeJoints:
joint.useSpring = false