Lever.cs

using UnityEngine;
using System.Collections;

public class Lever : MonoBehaviour
{
    // amount we want to move the lever by
    public Vector3 moveOffset = new Vector3(0f, -.5f, 0f);

    // default tween settings for moving up
    public float tweenTimeUp = .5f;
    public Tween.EaseType easeTypeUp = Tween.EaseType.BackIn;


    // default tween settings for moving down
    public float tweenTimeDown = .5f;
    public Tween.EaseType easeTypeDown = Tween.EaseType.BackOut;

    public bool stayDown = false;

    // is the lever pulled down?
    bool isDown;
    // stores the original local position of the lever so we can move back to it
    Vector3 originalLocalPosition;

    void Awake()
    {
        // store original local position so we can move back to it
        originalLocalPosition = transform.localPosition;
    }

    void OnMouseDown()
    {
        // if no tweens are happening right now
        if (Tween.Count(gameObject) == 0)
        {
            Toggle();
        }
    }

    void Toggle()
    {
        Tween.Stop(gameObject);
        if (isDown)
        {
            // if the lever is down, move it back up
            Tween.MoveTo(gameObject, originalLocalPosition, tweenTimeUp, easeTypeUp, true);
            Invoke("BackUp", tweenTimeUp);
        }
        else
        {
            // if the lever is up, pull it down
            Tween.MoveTo(gameObject, originalLocalPosition + moveOffset, tweenTimeDown, easeTypeDown, true);
            Invoke("PulledDown", tweenTimeDown);
        }
    }

    void BackUp()
    {
        // do whatever needs to happen when the lever is reset to its original position
        isDown = false;
    }

    void PulledDown()
    {
        // do whatever needs to happen when the lever is pulled down here
        isDown = true;

        if (!stayDown)
        {
            Toggle();
        }
    }
}