Fluid handling – Processes – With control of flow by a condition or characteristic of a...
Reexamination Certificate
1999-09-24
2001-11-13
Lee, Kevin (Department: 3753)
Fluid handling
Processes
With control of flow by a condition or characteristic of a...
C137S268000, C137S624200, C137S205500, C239S310000
Reexamination Certificate
active
06314979
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to horticultural liquid dispensation systems, and more particularly to a method and apparatus for injecting a liquid additive into a horticultural watering system. The invention is particularly apt for the injection of a liquid fertilizer, herbicide, fungicide, pesticide and/or mixture thereof into a conventional sprinkler system.
BACKGROUND OF THE INVENTION
Various approaches have been proposed for the injection of liquid additives into horticultural watering systems. Of particular interest, liquid fertilizers have been injected into watering systems employed in the turf growth/maintenance industry for many years.
Known approaches for liquid fertilizer injection have included both powered and non-powered systems. By way of primary example, metering pumps have been utilized in connection with golf course watering systems around the world. Such systems have proven too expensive to implement in many applications, including for example residential sprinkler systems.
Proposed non-powered systems have included venturi-type injectors and flow-through injectors. The venturi-type injectors have had limited success due to unacceptable attendant pressure loss in the system. Flow-through injectors provide for the flow of water through a reservoir, or pot, charged with a liquid or water soluble, granulated fertilizer. Such systems generally require recharging of the reservoir upon each use. Further, the reliable obtainment of a desired fertilizer application rate has proven problematic.
More generally in the later regard, it has been recognized that the application of small dosages of fertilizer to turf or foliage over an extended time is preferable to a single high dosage application. Low dosages avoid extreme growth spurt/burning cycles, and otherwise enhance the establishment of desirable root structures. In turn, susceptibility to pest and weed infestation is significantly reduced.
SUMMARY OF THE INVENTION
In view of the foregoing, a primary objective of the present invention is to provide a liquid additive injection apparatus/method for horticultural liquid dispensation systems that may be produced and operated on a cost effective basis. In this regard, the present invention avoids the use of motor-driven metering pumps or the like, and is therefore practical for both residential and commercial usage.
A further principal object of the present invention is to provide a liquid additive injection apparatus/method that is easy to implement. In this regard, the present invention can be readily incorporated into new or pre-existing horticultural watering and other liquid dispensation systems.
An additional important object of the present invention is to provide a liquid additive injection apparatus/method that provides for the selective injection of liquid additives into a horticultural watering system at one or more selectively established rates, thereby enhancing the desired plant response.
In one aspect of the present invention, a liquid injection apparatus is provided that includes a first valve, fluidly interconnected to a horticultural liquid dispensation system (e.g. a sprinkler/drip watering system), for selectively passing pressurized liquid (e.g. water) from the system into an injector. In turn, the injector mechanically forces a liquid additive into the dispensation system in direct response to the pressurized liquid. The injector may be fluidly interconnected to the first valve so as to internally receive liquid from the liquid dispensation system. Similarly, the injector may be fluidly interconnectable to a liquid additive reservoir so as to internally receive the liquid additive.
In one arrangement, the injector includes a piston slideably disposed within an internal chamber to define a tandem cylinder having a first internal portion when the piston is in a first position and a second internal portion when the piston is in a second position. The pressurized liquid from the liquid dispensation system may be received in the first internal portion (i.e., when the piston is disposed in its first position) and the liquid additive may be received in the second portion (i.e., when the piston is in its second position). In the later regard, a resilient member (e.g., a coil spring) may be provided (e.g. within the injector) to urge or bias the piston into the second position.
As will be further described, upon “opening” the first valve the fluid pressure within the liquid dispensation system may be employed to force the piston into the first position and thereby push a “slug” of liquid additive out of the second internal portion of the injector, while also deflecting (e.g. compressing) the resilient member. When the first valve is “closed”, the spring force of the deflected, or activated, resilient member may be employed to force the piston into its second position, thereby creating a vacuum within the second internal portion of the injector. Such vacuum may be utilized to draw or “suck” liquid additive into the injector for dispensation upon the next piston “stroke”. In this manner, discrete liquid additive increments may be injected into the liquid dispensation system.
In order to provide for the effective receipt and dispensation of liquid additive from within the injector, the piston may include a seal member positioned about at least one end of the piston to slideably and sealably engage an internal wall within the injector. Most preferably, a first seal member is positioned about a first end of the piston to slideably and sealably engage a first internal wall portion and a second seal member is positioned about a second end of the piston to slideably and sealably engage a second internal wall portion.
In another aspect of the present invention, a liquid additive injection apparatus is provided for use with a liquid dispensation system (e.g. a sprinkler/drip watering system) that includes a main controller for transmitting signals to control the flow of water within the liquid dispensation system (e.g. control signals to solenoid valves). The inventive injection apparatus includes a first valve fluidly interconnectable to the liquid dispensation system and an injector fluidly interconnected to the first valve for injecting a liquid additive into the liquid dispensation system in response to the receipt of pressurized liquid from the system through the first valve. In the later regard, the first valve is provided to selectively pass the pressurized liquid to the injector in response to the sensed transmission of control signals by the main controller of the liquid dispensation system.
In conjunction with this inventive aspect, the control signals transmitted by the main controller may be electrical and the first valve may be electrically actuateable. Relatedly, the injection apparatus may include an injection controller, electrically interconnectable to the main controller and the first valve, for sensing the main controller control signals and for responsively transmitting electrical pulses to open/close the first valve. The injector dispenses a predetermined amount, or “slug”, of liquid additive into the liquid dispensation system in response to each pulse received by the first valve (i.e. a single slug per open/close cycle).
In yet a further aspect of the present invention a liquid injection apparatus is provided for use with a liquid dispensation system that comprises a main controller for transmitting control signals to each of a plurality of different coverage zones to selectively effect liquid dispensation within each of the different coverage zones. The inventive apparatus provides for the injection of a liquid additive into the liquid dispensation system at a rate that is selectively pre-established on a coverage zone-specific basis. For example, when used with a conventional water sprinkler system, a liquid additive injection rate of x may be established for a first watering zone, a liquid additive injection rate of y may be established for a second watering zone, a liquid additive injection rate of z may be establish
Fertigator, Inc.
Lee Kevin
Marsh & Fischmann & Breyfogle LLP
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