Positioner having user-adjustable dynamic response
AssigneeFisher Controls International LLC
InventorsGeorge W. Gassman, Gerald F. Varnum
Life of this patent
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Abstract
A positioner-actuator control system includes a pair of relays and a pivotally mounted beam for operation thereof in response to a pneumatic control signal. A summing beam has forces applied to it from an input signal, a controlled device position lever, a zero adjustment and a damping mechanism comprising a pair of flat springs attached to the relay beam and to the summing beam. A clamp is movable along the flat springs to permit user adjustment of the damping force.
Claims12
A positioner system for controlling the position of a controlled device in accordance with an input signal comprising:
- output means for controlling the position of said controlled device;
- summing means for integrating said input signal with a signal representative of the position of said controlled device and for producing a command signal for said output means;
- adjustable damping means including user-adjustable variable rate spring means for tailoring the dynamic overshoot characteristic of said system to accommodate a wide range of controlled devices;
- said variable rate spring means affecting said overshoot characteristic without substantially affecting static characteristics of said system;
- said variable rate spring means comprising a pair of spring members, each having one end coupled to a respective one of said output means and said summing means;
- and
- a movable clamp for simultaneously changing the effective lengths of said spring members to alter the damping effect on said summing means.
A pneumatic positioner system for driving an actuator for controlling the position of a valve stem in accordance with an input signal comprising:
- summing means for integrating a plurality of forces applied thereto and producing a command signal as a function thereof;
- relay means responsive to said command signal for driving said actuator;
- means translating and applying said input signal as a force to said summing means;
- means coupling said command signal to said relay means;
- means applying a force to said summing means as a function of the position of said valve stem;
- and
- variable damping means including a spring member having an adjustable spring rate coupled between said relay means and said summing means for applying damping forces to said summing means.
A positioner for controlling the mechanical position of a controlled device in response to an input signal comprising:
- summing means for integrating a plurality of forces and for generating a command signal as a function thereof;
- means translating said input signal into an input force on said summing means;
- relay means for controlling the position of said controlled device in response to said command signal, said relay means including motion amplifying means comprising a pivotally mounted relay beam;
- means applying a force to said summing means indicative of the position of said controlled device;
- and
- variable damping means including a flexible flat spring member for applying a force to said summing means from said pivotally mounted relay beam for damping movement of said summing means, said flat spring member having an adjustable spring rate.
A system for controlling the mechanical position of a controlled device in response to an input signal, comprising:
- a summing beam for integrating a plurality of forces and for producing a command signal as a function of said integration;
- relay means, including motion amplifying means, for controlling the position of said controlled device in response to said command signal;
- means applying a force to said summing beam indicative of the position of said controlled device;
- means converting said input signal into an input force and for applying said input force to said summing beam;
- and
- adjustable damping means for applying a force to said summing beam from said motion amplifying means for dynamically controlling movement of said controlled device, said adjustable damping means comprising a variable rate spring that is user-adjustable and adjustment of which has substantially no effect on the static characteristics of the system.
A pneumatic positioner-actuator system for controlling the position of a valve stem as a function of an input signal comprising:
- a summing beam for integrating a plurality of forces applied thereto and for producing a pneumatic command signal as a function of said integration;
- relay means including a pair of relays controlled by a pivotally mounted relay beam;
- an actuator connected to said valve stem and being under control of said relays;
- a positioner lever applying a force on said summing beam indicative of the position of said position lever;
- means supplying said pneumatic signal to said relay beam;
- adjustable damping means connected between one arm of said relay beam and said summing beam for damping movement of said beam, said adjustable damping means comprising a user-adjustable device having substantially no effect on the static characteristics of the system;
- and
- said adjustable damping means including a pair of flat springs, each having one end connected to one of said relay beam arm and said summing beam, respectively, and a movable clamp slidable along the length thereof, said springs being oriented in parallel.
Dependencies are inferred from the claim text.