Table schema:
CREATE TABLE table_name_84 (constructor VARCHAR, time_retired VARCHAR, laps VARCHAR, grid VARCHAR)

Question: When grid is less than 7, laps are greater than 17, and time/retired is + 1:35.6, who is the constructor?
SQL: SELECT constructor FROM table_name_84 WHERE laps > 17 AND grid < 7 AND time_retired = "+ 1:35.6"