1. Why the Design changed
Lowering forks- disengage trays at ground position
Locking/releasing forks at ground position
Improve ergonomics

3. 3 way valve opens to pressure line
Start
Air goes into cylinder
3 way valve opens to pressure line
Forks lower
Dolly and trays loaded
Forks lock
Is switch activated
Restart Process
Is valve switched to open position No
Yes No
Yes
Forks raise to home position

4. Adjustable needle valve
3 way valve
Air from line
Muffler
Air regulator
Adjustable needle valve
Emergency relief ball valve
Air cylinder
(2 inch bore and max of 125 lbs to lower requires ~40psi)

5. 5th has been placed and is descending
Line is unpressurized
3 Way Normally Open to Atmosphere Push-Valve

6. 5th tray has
fully descended
Line is pressurized
Switched pressed, wheels on ground

7. Piston Pressurized, lowering piston slowly
Forks lower,
trays in contact with floor only

8. Filled until 40 psi is reached and cylinder is locked in down position

9. Open to ATM closed to pressurized line
Compressed air released to ATM

10. Piston raises, acting as air damper
Open to ATM again