Pennsylvania constitution
Article V: the judiciary
Section 18

Until otherwise provided by law, the present judges of the court of common pleas shall continue to act as the judges of that court; the present judges of the county court shall become judges of the court of common pleas; the present judges of the orphans' court shall become judges of the orphans' court division of the court of common pleas; the present judges of the juvenile court shall become judges of the family court division of the court of common pleas.