Method and apparatus for delivering constant water flow rates to a fire hose at each of a plurality of selectable flow rate settings

• US 3,974,879 A
• Filed: 02/14/1975
• Issued: 08/17/1976
• Est. Priority Date: 02/14/1975
• Status: Expired due to Term

• Current Assignee: Grumman Aerospace Corporation (Northrop Grumman Corporation)
• Original Assignee: Grumman Aerospace Corporation (Northrop Grumman Corporation)
• Inventors: Kaplan, Herman, Nelson, George R. Jr.
• Primary Examiner(s): Blunk, Evon C.
• Assistant Examiner(s): Mar, Michael
• Application Number:
  US05/550,044
• Time in Patent Office: 550 Days
• Field of Search: 169/24, 169/13, 169/43, 251/131, 239/172, 417/26, 417/28, 417/282, 417/300
• US Class Current: 169/43
• CPC Class Codes: A62C 27/00 Fire-fighting land vehicles

Abstract

A method and apparatus for delivering constant water flow rates to the fire hose of a pumper truck at each of a plurality of selectable flow rate settings including the steps of transmitting a digital signal corresponding to a particular fire hose and pumper truck, receiving and decoding the digital signal, activating a multi-position valve in response to the decoded signal to set a particular valve position, and maintaining a constant flow rate to the fire hose by automatically varying the valve position in response to changes in the output pressure of the pump and pressure drop in the fire hose.

Claims

1. A method of delivering constant water flow rates to a fire hose of a fire pumper truck at any one of a plurality of discrete selectable flow rate settings, comprising the steps of:

transmitting a digital signal corresponding to a particular fire hose, a particular fire pumper truck, and a water flow rate;

receiving and decoding the digital signal;

activating a discrete multi-position valve having a plurality of discrete predetermined water flow rate settings with the decoded signal to set the multi-position valve for delivering a predetermined water flow rate to the fire hose; and

adjusting the water flow through the multi-position valve in response to changes in input water pressure and output back pressure to the multi-position valve to maintain the predetermined water flow rate until another corresponding digital signal is transmitted, received and decoded for activating the multi-position valve.

2. The method of claim 1 including the step of:

preventing cavitation of the water pump in the fire pumper truck.

3. The method of claim 1 including the step of:

increasing or decreasing the predetermined water flow rate of the discrete multi-position valve one discrete setting upon application of a signal to the multi-position valve.

4. The method of claim 1 including the step of:

sensing the output pressure of the water pump;

comparing the sensed output pressure of the water pump with a preset pump pressure;

controlling the pump output pressure to correspond with the preset pump pressure.

5. An adjustable flow rate control system for a fire pumper truck which provides constant water flow rates to the fire hoses coupled thereto at a plurality of discrete selectable flow rate rate settings, comprising:

digital transmitting means coupled to the nozzle of each individual fire hose for transmitting a digital signal having a predetermined frequency and corresponding to a particular fire hose, a particular fire pumper truck, and a water flow rate;

receiving means in the fire pumper truck for receiving and decoding the digital signals transmitted from said transmitting means;

discrete multi-position valve means having a plurality of discrete water flow rate settings for providing a predetermined water flow rate to the proper fire hose in response to transmission of the proper digital signal from said transmitting means and receipt and decoding by said receiving means;

valve control means for controlling the movement of said multi-position valve means in response to a decoded output signal from said receiver to provide an increase or decrease in the discrete water flow rate setting in accordance with the digital signal transmitted by said digital transmitting means;

automatic flow rate control means for automatically adjusting the water flow through said multi-position valve means in response to changes in input water pressure or output back pressure to maintain a the selected discrete water flow rate to each fire hose in accordance with the setting of the multi-position valve.

6. The system of claim 5, including:

governor means for maintaining a constant output pressure at the water pump of the fire pumper truck.

7. The system of claim 5, including:

anti-pump cavitation means for preventing cavitation of the water pump of the fire pumper truck.

8. A method of delivering constant water flow rates to a fire hose of a fire pumper truck at each of a plurality of selectable flow rate settings, comprising the steps of:

transmitting a digital signal corresponding to a particular fire hose and a particular fire pumper truck;

receiving and decoding the digital signal;

activating a multi-position valve with the decoded signal to set a particular valve position with a predetermined water flow rate;

maintaining the predetermined water flow rate to the fire hose by automatically varying the valve position in response to changes in input water pressure and output back pressure to the multi-position valve;

automatically decreasing the predetermined water flow rate of the multi-position valve to a lesser predetermined water flow rate during periods of insufficient water and maintaining the lower predetermined water flow rate for a specified period of time in an effort to attain stability; and

further decrementing the water flow rate one setting at a time until stability is attained.