If you have valid LTR when you leave the country and return with with new Dependant visa continous visa is not broken under 10 yr rule.
Example
A person enters the UK on 1 September 2004 with entry clearance as a student which is valid until 31 October 2005. On 25 October 2005 (before the previous leave expired) the person departs the UK. On 5 January 2006 the person re-enters the UK with valid entry clearance as a student. Will the person’s continuous residence be deemed to be broken?
No. Because the person had valid leave on the date of their departure and the date of their return and the time spent outside the UK was less than 6 months, continuous residence has been maintained, even though they re-entered with a fresh grant of leave.
Contents
http://www.ukba.homeoffice.gov.uk/sitec ... chapter18/
Hope this helps
