The present disclosure generally relates to a discharge valve feather control for a firefighting vehicle.
Firefighting is a highly dangerous occupation that subjects firefighters to many hazards. It is critically important that firefighters have the right amount of water flow (gallons per minute or gpm) when they are combating a fire in various conditions and environments. Determining the water flow rate in a fire hose is an important task for firefighters responsible for operating fire apparatus pumps. Delivering water at the proper flow rate and pressure to firefighters controlling the fire hose nozzles is vital to ensure safe operations. Pressures and flow rates too low will be insufficient for fire control, while pressures and flow rates that are too high creates dangerous conditions with handling the nozzle, burst hose, and other hazards.
Presently there are electric devices for controlling opening and closing discharge valves on a firefighting vehicle, such as a tanker or pumper fire engine. These electric control devices operate at set speeds to open or close the valve. When a firefighter desires to make small adjustments of the discharge valve to change the flow rate from 100 gpm to 105 or 110 gpm, for example, it is very easy to overshoot the desired setting, and multiple manipulations of the controls are often required to reach the desired flow rate.
The automatic valve feather control system includes a microprocessor or microcontroller 20 that receives the activation signals of three valve control switches 22-24. Control switch 22 and control switch 23 are operable to instruct a drive motor 26 to open and close the discharge valve 10, respectively. These control switches 22 and 23 are preferably disposed on a pump panel equipped with many levers, switches, and gauges, including the position indicator 16 of the discharge valve 10. The pump panel is typically a collection of levers and switches that controls how much water is flowing and which lines are being discharged from the pumper/tanker. Typically, activating the open control switch 22 causes the discharge valve 10 to open, and activating the close control switch 23 causes the discharge valve 10 to close. The amount of time the control switches 22 and 23 are activated (pressed) determines the extent the valve is opened or closed.
A third control switch 24, is provided as a feather control switch. When activated, the control switch 24 sends a feather control signal to the microprocessor or microcontroller 20. As a result, the microcontroller 20 generates a signal that is operable to slow down the drive motor (electric, pneumatic, or hydraulic) 26 to the discharge valve 10. Accordingly, when the feather control switch 24 is activated (e.g., pressed) substantially at the same time or while the open control switch 22 or the close control switch 23 is activated, the microcontroller 20 instructs the drive motor 26 to operate at a slower predetermined rate, which enables smaller or finer adjustments to the setting of the discharge valve 10 to be made. When the feather control switch 24 is deactivated or not pressed while the open or close control switch 22 or 23 is not activated, the drive motor 26 runs or operates at the normal predetermined speed. As shown in
Accordingly, activating the feather control switch 24 enables smaller incremental changes to be made in the setting of the discharge valve 10, so that the desired discharge setting can be achieved more easily.
In a second embodiment, activation of the feather control switch 24 is operable to slow down the drive motor speed for a predetermined period of time, when the open or close control switch 22 or 23 is also activated. As a result, the activation of the open or close control switch 22 or 23 during this time period is affected by the feather control signal, resulting in a slower drive motor speed and finer changes to the discharge valve setting. After the predetermined period of time has lapsed, the drive motor speed automatically resumes to the normal speed. This predetermined period of time can be from ½ second to 3 seconds, for example. The predetermined time period of activation for feathered control may also be programmable and/or modifiable on-the-fly according to the pump operator's preference, for example. In operation, the feather control switch 24 does not need to be continually activated (pressed) while the open or close control switches 22 or 23 is activated, which may simplify operations.
In further embodiments, the microcontroller 20 further receives sensor inputs from one or more pressure transducers 30 and flow rate meters 32 disposed inline of the fluid flow, such as upstream of the discharge valve 10. The microcontroller 20 may make calculations that take these input data into account and modulate the control signals in response to these sensor data inputs.
Accordingly, by using the feather control switch 24 the operation of the discharge valve 10 can be more refined to make smaller and more precise adjustments to the setting of the discharge valve 10 when needed.
The drive motor speed can be varied by a number of ways dependent on the type of motor that is used to operate the discharge valve. For an electric motor, pulse width modulation or voltage control techniques may be used. For a pneumatic (air) motor, pressure or flow regulation techniques may be used. For a hydraulic motor, flow regulation techniques may be used. Accordingly, the microcontroller 20 is adapted to generate suitable controls signals to modify the drive motor speed according to the input of the controls switches 22-24.
It should be noted that the word “water” is used herein to generally convey the concept of a fluid used for firefighting purposes, and “water” may include water, foam, chemicals, and other types of fire-suppression fluids.
Further notice should be given regarding the actual implementation of the system in that certain changes and modifications to the described system, though not described explicitly or in detail, are contemplated herein. For example, the microcontroller may be implemented using one or more CPU, or micro-controller circuits. Further, it is understood that a CPU is typically in operation with its attendant circuitry and software, such as memory, interfaces, drivers, etc. as known in the art. Additionally, although not shown explicitly, the system includes memory that may be implemented using one or more data storage devices of a variety of types now known or later developed. Similarly, the system may employ wireless communication that may be achieved using any technology and protocol suitable for the firefighting application. Although wireless communication is the general way information may be conveyed, the communication between the microcontroller and any controlled component and sensor may be achieved by wired and/or wireless means.
The features of the present invention which are believed to be novel are set forth below with particularity in the appended claims. However, modifications, variations, and changes to the exemplary embodiments described above will be apparent to those skilled in the art, and automatic fire pump control system and method described herein thus encompasses such modifications, variations, and changes and are not limited to the specific embodiments described herein.
The present application claims the benefit of Provisional Patent Application No. 61/726,659 filed on Nov. 15, 2012.
Number | Date | Country | |
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61726659 | Nov 2012 | US |