US 12,135,048 B2
Piston limit sensing for fluid application
Daniel Robert Zientara, Lakeville, MN (US); Lam Huu Nguyen, Woodbury, MN (US); and Fei Wu, Baltimore, MD (US)
Assigned to Wagner Spray Tech Corporation, Plymouth, MN (US)
Filed by Wagner Spray Tech Corporation, Plymouth, MN (US)
Filed on Sep. 6, 2018, as Appl. No. 16/123,680.
Claims priority of provisional application 62/555,280, filed on Sep. 7, 2017.
Prior Publication US 2019/0072118 A1, Mar. 7, 2019
Int. Cl. F15B 15/28 (2006.01); B05B 9/04 (2006.01); B05B 12/00 (2018.01); F04B 9/08 (2006.01); F04B 9/105 (2006.01); F04B 15/02 (2006.01); F04B 17/06 (2006.01); F04B 49/06 (2006.01); F15B 13/044 (2006.01); G01R 33/07 (2006.01); B05B 9/00 (2006.01)
CPC F15B 15/2807 (2013.01) [B05B 9/0409 (2013.01); B05B 9/0413 (2013.01); B05B 12/004 (2013.01); F04B 9/08 (2013.01); F04B 9/105 (2013.01); F04B 15/02 (2013.01); F04B 17/06 (2013.01); F04B 49/065 (2013.01); F15B 13/044 (2013.01); G01R 33/07 (2013.01); B05B 9/007 (2013.01); F04B 2201/0201 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A liquid delivery system comprising:
a source of hydraulic fluid;
a hydraulic cylinder fluidically coupled to the source of hydraulic fluid and having a hydraulic piston movable between a first limit position and a second limit position;
a rod connected to the hydraulic piston and extending out of the hydraulic cylinder;
a liquid cylinder comprising a liquid piston, operably driven by the rod, to pump a liquid along a flow path to a fluid applicator;
a housing assembly disposed between the hydraulic cylinder and the liquid cylinder, the housing assembly including a first wall and a second wall that are spaced apart to define a first opening and a second opening;
a sheath and a collar which are disposed within the housing assembly and couple the liquid piston to the rod, wherein at least one of the sheath or the collar comprises a ferrous metal;
a sensor device disposed entirely within the housing assembly and located outside the hydraulic cylinder, the sensor device comprising a potting body that hermitically seals a magnet therein, and the sensor device configured to generate a sensor signal indicative of a sensed position of the at least one of the collar or the sheath comprising the ferrous metal;
a controller configured to:
derive a position of the hydraulic piston based on the sensor signal; and
based on the position of the hydraulic piston, actuate a solenoid valve to control a flow of the hydraulic fluid between from the source of hydraulic fluid and the hydraulic cylinder;
a first cover configured to couple to the first wall and cover the first opening; and
a second cover spaced apart from the first cover and configured to couple to the second wall and cover the second opening.