Version 5 with Spiral/Helical GearMay 1, 2015/in InventionModeling and simulation complete . . . next: rapid manufacture to produce five valves for field test. https://vsillc.com/wp-content/uploads/2015/04/V5-HBG-Drive1.png 915 1049 yimprosvsillc https://vsillc.com/wp-content/uploads/2015/05/vsi-logo.png yimprosvsillc2015-05-01 09:40:092015-07-26 16:45:10Version 5 with Spiral/Helical Gear