US 9,810,245 B2
Spring return actuator
Gaby Jaccoby, Carmiel (IL); Ido Navon, Lower Galilee (IL); Yoel Hadar, Kiryat Shmona (IL); and Efraim Maayan, Galil Elion (IL)
Assigned to Habonim Industrial Valves & Actuators Ltd., Galil Elion (IL)
Filed by Habonim Industrial Valves & Actuators Ltd., Galil Elion (IL)
Filed on Mar. 15, 2013, as Appl. No. 13/831,851.
Prior Publication US 2014/0260953 A1, Sep. 18, 2014
Int. Cl. F15B 15/14 (2006.01); F15B 15/02 (2006.01); F15B 15/06 (2006.01); F15B 20/00 (2006.01)
CPC F15B 15/02 (2013.01) [F15B 15/1409 (2013.01); F15B 15/1476 (2013.01); F15B 15/065 (2013.01); F15B 20/004 (2013.01); F15B 2211/7052 (2013.01); F15B 2211/7055 (2013.01); F15B 2211/863 (2013.01); F15B 2211/8752 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A spring-return actuator comprising:
a first piston housed in a first cylinder chamber, the piston movable from a first to a second position by pressurized fluid to move a load;
a safety system comprising a second piston moveable in a second cylinder chamber by the pressurized fluid to arm the safety system, the safety system configured to disarm to provide force to move the first piston from the second position toward the first position, when pressure of the pressurized fluid drops below a safety pressure threshold; and
a differential fluid channel in cooperation with the first and second cylinder chambers and configured to provide pressurized fluid simultaneously to both the first and second chambers and provide pressurized fluid to the first chamber only to move the first piston towards the second position and provide pressurized fluid to the second chamber only to arm the safety system and provide flow of the pressurized fluid into the first cylinder chamber at a first flow rate while simultaneously providing flow of the pressurized fluid into the second cylinder chamber at a second flow rate, greater than the first flow rate so that the first piston while moving the load is disengaged from the safety system being armed by motion of the second piston;
wherein the differential fluid channel comprises a one-way contraction valve that causes contraction of the fluid channel providing pressurized fluid to the first piston.