Methods and apparatus related to feedback control for electro-pneumatic control systems are disclosed. An example electro-pneumatic control system comprises an electro-pneumatic controller and a secondary pneumatic power stage coupled to the electro-pneumatic controller to provide a feedback signal to the electro-pneumatic controller.
A sealing washer includes a connecting portion and an inner edge portion disposed radially inward of the connecting portion. The inner edge portion terminates in an edge disposed in an edge plane that is offset from the connecting portion. The sealing washer may be used, for example, to form a seal between a bolt and an elastomeric sheet, by forming a tight seal as the bolt is tightened.
- Marshalltown IA, US Christopher S. Metschke - Ames IA, US
Assignee:
FISHER CONTROLS INTERNATIONAL LLC - Marshalltown IA
International Classification:
G05D 16/20 F15B 13/04
Abstract:
A relay valve configured according to the various embodiments as described herein advantageously provides consistent, reliable start point pressures for both supply and exhaust functionalities. To achieve this, the relay valves described herein utilize a plurality of diaphragms to neutralize any variable forces due to pressure in an actuator and, optionally, a supply connected to the relay valve.
Terminal Box Apparatus With Side Wall Entrance And Curved Wiring Guide
- Marshalltown IA, US Christopher Metschke - Ames IA, US Roger Lynn Heatwole - Marshalltown IA, US Brendan Piscitelli - Marshalltown IA, US
International Classification:
H02G 3/08 H02G 3/14
Abstract:
A terminal box comprising a housing having a base, a side wall extending from the base, and a first opening opposite the base to provide access to wiring terminals to be mounted adjacent an inner surface of the side wall. The terminal box further includes a second opening in the side wall, the second opening providing access to a curved wiring guide within the housing. The curved wiring guide is shaped to guide electrical wires away from the base and toward a central portion of the first opening.
Apparatus To Bias Spool Valves Using Supply Pressure
Apparatus to bias spool valves using supply pressure are disclosed. An example apparatus includes a sleeve of a spool valve, and a spool within the sleeve to control a flow of fluid at a supply pressure through the spool valve as the spool is moved relative to the sleeve in response to a variable input force. A biasing force is to bias the spool opposite the variable input force. The biasing force is to be generated from a biasing pressure of the fluid within a chamber adjacent a biasing end of the spool. The biasing pressure is to be based on the fluid at the supply pressure provided directly to the chamber from a supply of the fluid independent of the flow of the fluid through the spool valve.
Methods And Apparatus To Bias Spool Valves Using Supply Pressure
Methods and apparatus to bias spool valves using supply pressure are disclosed. An example apparatus includes a housing of a spool valve, the housing including a first port to receive a fluid at a supply pressure. The example apparatus further includes a spool within the housing. A position of the spool is to be selectively controlled via an input force acting on the spool, the position of the spool to define a path of a flow of the fluid through the spool valve from the first port to a second port of the housing. A biasing force is to bias the spool opposite the input force, the biasing force to be generated from the supply pressure applied to an end of the spool.