| 摘要 |
324,172. Barclay, J. S. Nov. 29, 1928. Davits of the gravity type which have an athwart ship movement on inclined guides accompanied by a luffing movement occuring at the termination of the athwart ship movement have these movements controlled by falls which running from a winch 17, pass over a pulley 18 on the davit frame 4 and back to a pulley 20 coaxial with the roller 18 after the fall has been looped around a pulley 19 on the davit 9. The fall finally passes over fairleads 21, 22 to the boat. This arrangement constitutes a triple purchase gear for controlling the movements of the davit on the guides 4. The fall further controlling the luffing movement of the davit about the roller 11 until the base of the davit abuts on the stop 16 whereupon the fall acts as a single purchase gear during the boat-lowering operations. |
