US 11,655,912 B2
Bellows diaphragm assembly
Ryan Johnson, Fort Collins, CO (US); and Ken Kawakami, Fort Collins, CO (US)
Assigned to Hitachi Metals, Ltd., Tokyo (JP)
Filed by Proterial, Ltd., Tokyo (JP)
Filed on Jan. 14, 2021, as Appl. No. 17/149,616.
Prior Publication US 2022/0221082 A1, Jul. 14, 2022
Int. Cl. F16K 41/10 (2006.01); F16K 31/44 (2006.01); G05D 7/06 (2006.01); G05D 7/01 (2006.01)
CPC F16K 41/10 (2013.01) [F16K 31/44 (2013.01); G05D 7/0635 (2013.01); G05D 7/0113 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A mass flow controller, comprising:
a flow path including a control valve cavity comprising a control valve cavity inlet port and a control valve cavity outlet port;
a mass flow meter configured to measure a mass flow rate of a gas flowing through the flow path;
a controller configured to provide an actuator control signal responsive to a mass-flow-rate signal from the mass flow meter;
an actuator configured to move in response to the actuator control signal; and
a diaphragm assembly configured so at least a portion of the diaphragm assembly moveably extends and retracts within the control valve cavity, the diaphragm assembly comprising:
an aperture;
side walls extending from the aperture and disposed about a central axis, the side walls including multiple convolutions configured to deform along the central axis and exert a restoring compressive or expansive spring force when deformed;
a poppet including an interior surface facing the aperture and an exterior sealing surface facing the control valve cavity inlet port, wherein the restoring spring force biases the poppet to a default, resting position; and
a push rod extending from the interior surface of the poppet, along the central axis, through the aperture to enable the push rod to couple to the actuator, wherein the push rod moves, responsive to motion of the actuator, along the central axis to enable the exterior sealing surface of the poppet to open and close the flow path through the control valve cavity.