[jQuery] inherited private variables

[PragueExpat]

I posted this in comp.lang.javascript also, but would like to hear
from the jQuery group.

I (think) that I've come up with a pattern that I haven't seen in any
publications so far and I would like some feedback. Basically, I was
looking for a way to inherit private functions and I came up with
this:

//base private object constructor

function priv(){
    this.a = 1;
    this.b = 2;
}

//private object constructor that inherits from base private object

function priv2(){
    this.c = 3;
    this.d = 4;
}
priv2.prototype = new priv();

//constructor that uses private object in private namespace

function ob(){
    var _ = new priv2();
    return {
        go:function(){
            alert(_.a);
        }
    }
}

var test = new ob();

//returns 1

test.go();

//only go() is public

test;

-------------------------------------------

First of all, is this a known pattern? If so, sorry for the redundant
information. If not, are there any drawbacks that you can see? The
advantage, as I see it, is that inherited objects can also inherit
private functions and properties for use.

Any feedback would be welcome.