var Factory = function (argument) {
	return new Factory.prototype.constructor(argument);
};

Factory.prototype = {
	'constructor': function (argument) {
		this.argument = argument;
		return this;
	}
};

Factory.prototype.constructor.prototype = Factory.prototype;

// Examples...
var instance = Factory('Argument');
instance.argument === 'Argument';
instance instanceof Factory;
instance instanceof Factory.prototype.constructor;

// But...
instance.constructor !== Factory;
instance.constructor === Factory.prototype.constructor;