摘要 |
A hydraulic systme (30) suitable for raising, lowering, floating and locking a cutting deck (16). Hydraulic circuit (30) preferably includes a back pressure system (40) for automatically, or manually, applying a preferred back pressure to hydraulic cylinders (24) to "float" decks (16). Connected to back pressure system (40) is an actuation system (42) which can automatically or manually act on back pressure system (40) to change the back pressure depending on conditions. For example, it may be desirable to increase the back pressure when mower (10) encounters a hill to transfer more weight from the cutting unit (16) to the traction vehicle (12) of mower (10). |