Re-entry minimum lapsed time for B-1 visitor

[B.S.Shankara]

My self and my wife holding multiple entry visa visited our daughter last year and returned on Feb 18th 2009 after 3 months stay. As we are looking after our grand daughter in India and who may need to be taken to USA soon to be with her mother, I would we grateful if a clarification is made regarding:

any minimum period of stay outside USA, if any, after the first entry and stay period before re-entering within a span of one year.

Will the second period of stay, if and when granted after arrival in USA, will be affected by the actual period of stay after the first entry ?

Can I locate these rules, if any, in any website for authenticity? If so where?
Thanks in advance.
B.S.Shankara, 62 yrs.

[delhiramanathan]

The untold rule is that if you have stayed in USA for 3 months, then, you are expected to stay in your home country for more than 3 months to have a smooth entry when you visit USA next.
Please note B2 visa is for visitor and you fall in that catagory.