It has been proposed in the past to utilize a permanently installed system of conduits such as pipes or the like having nozzles connected thereto to spray areas such as dairy barns, food processing plants and the like for extermination of insects of the type which are a source of contamination, annoyance, disease, etc. While such insecticides are generally effective in insect extermination there is always the problem of spraying a precise amount of insecticide within critical limits so that no more or less of insecticide is sprayed than necessary. As has been recognized, less than the desired amount of insecticide results in inadequate extermination and an excess of insecticide result in contamination of the area or materials sprayed.

It has also been proposed in the past to utilize insecticide containers containing a measured volume of insecticide, the containers being emptied during each spray cycle and replaced after the spraying operation. It has even been proposed to utilize containers of the aerosol type containing a single dosage of insecticide packaged in the well known insecticide gaseous propellant mixture so that evacuation of the mixture in the aerosol container provides the desired measured volume to be sprayed through the nozzles in the distribution system. Example of such a system is shown in U.S. Pat. No. 3,614,841 entitled EXTERMINATION METHOD issued on Oct. 26, 1971 to the applicant herein.

In such prior insecticide distribution systems where specific dosages of insecticide must be dispensed periodically, the requirement for dispensing a precise amount of insecticide has presented a number of limitations. For instance, to provide a measured volume of insecticide during each spraying operation, the container must be replaced or refilled during each operation. In addition, subsequent to each spraying operation, the distribution system is substantially emptied of insecticide and each subsequent spraying operation means that the conduits forming the system must be refilled before the actual spraying through the nozzles is accomplished. This means that air can enter the system following each spraying operation which must be evacuated further interfering with the efficiency of the spraying operation. Furthermore, for effective use of the gaseous propellant in the mixture during spraying, the full force of the propellant should be behind the liquid insecticide and in such present day systems, there is a tendency of the propellant to flow back from the nozzles in the conduits with an attendant reduction in pressure at the nozzles and a resulting weak spray of insecticide. It can further be easily seen that in such present day systems, the amount of labor required for container replacement, valve actuation etc. imposes a considerable burden in the operation of such systems.

Accordingly, a primary object of this invention is to provide a new and novel insecticide spray system utilizing an aerosol container which permits the system to be completely filled with an insecticide-gaseous propellant mixture so as to maintain the system under equilibrium areosol conditions during periodic spraying operations.

Still another object of this invention is to provide a new and novel insecticide spray system having nozzles for spraying insecticide which are automatically actuated for periodic timed intervals in a manner characteristic of an aerosol container.

A still further object of this invention is to provide a new and novel insecticide spray system in which an aerosol type insecticide-gaseous propellant mixture is maintained throughout the system under equilibrium pressurized conditions in which the insecticide is efficiently and uniformly sprayed through the nozzles during each spraying operation.

This invention further contemplates a provision of new and novel insecticide spray system which is capable of prolonged operation without replenishment while dispensing through nozzles specific dosages of insecticide in selected areas automatically and which permits easy evacuation of entrapped air in the system prior to each replenishment operation.

Still another object of this invention is to provide a new and novel insecticide spray system utilizing an aerosol container and a plurality of conduits having nozzles for spraying areas of any selected breadth but which permits various portions of the system to be disconnected from the system for spraying selected areas only.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the following drawings.

In general the object of this invention and other related objects are accomplished by providing a main conduit and at least one branch conduit connected at one end to the main conduit and having a closed other end with at least one normally closed spray nozzle connected to the branch conduit. An aerosol container containing a selected mixture of an insecticide-gaseous propellant is provided with an outlet which is connected to the main conduit to fill the main conduit and branch conduit with the mixture so that the mixture in the conduits is maintained under equilibrium condition with the mixture in the container. Means are provided for opening the nozzle to spray an area adjacent thereto and timing means are operatively associated with the nozzle opening means for periodically opening the nozzle for a selected timed interval to spray a specific dosage of insecticide within the adjacent area.

The novel features which are believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a diagramatic representation of the insecticide spray system of the invention;

FIG. 2 is an enlarged view of a portion of the system of FIG. 1; and

FIG. 3 is an enlarged view of that portion of the system of FIG. 1 shown in the circle.

Referring now to the drawings and to FIG. 1 in particular, there is shown an insecticide spray system constructed in accordance with the invention which, as will be explained hereinafter, is utilized to spray areas which may be open or within enclosures or both where infestation and contamination by insects and the like is to be eliminated. The system of FIG. 1 includes a header or main conduit 11 formed of copper tubing or the like which may be of any selected length in accordance with the extent of the area to be sprayed. As can be understood, one end 11a of the main conduit 11 is arranged to be detachably connected by means such as an adapter 12 to the outlet 13a of a container and, in particular, an aerosol cylinder 13 containing a selected mixture of an insecticide and a gaseous propellant in the well known manner. The other end 11b of the main conduit 11 is arranged to be suitably closed and may be of and selected length in accordance with the extent of the area to be sprayed.

At least one branch conduit 14, which may be similarly constructed of copper tubing or the like, is arranged to be connected at one end 14a to the main conduit 11 in communication therewith, two of such conduits 14, 14' being shown in FIG. 1 and having like numerals to identify like parts. As shown, the branch conduits 14, 14' have ends 14a and 14a' connected to the main conduit 11 in spaced relationship. It should be understood that as many branch conduits as desired may be utilized depending on the extent of the area to be sprayed and the areas to be sprayed may be either open spaces or areas within enclosures such an enclosures 16, 16' shown in broken lines in FIG. 1 in association with the branch conduits 14, 14' respectively.

The other ends 14b, 14b' of the conduits 14, 14' respectively are closed preferably by means of manually operated valves 17, 17' respectively. The valve 17, 17' are bleed valves for a purpose to be explained hereinafter and are normally maintained in the closed condition. In the description to follow, reference will be made to branch conduit 14 but it should be understood that the description es equally applicable to conduit 14'.

At least one normally closed, spray nozzle is positioned on each of the branch conduits and preferably a plurality of normally closed nozzles 18 are provided on the branch conduit 14 in spaced relationship in accordance with the extent of the area to be sprayed. Similarly, nozzles 18' are provided on branch conduit 14'. It should also be understood that the nozzles 18 are similar in construction and that the description to follow will be directed to a single nozzle.

Means are provided for opening the normally closed nozzle 18 for spraying an area adjacent the nozzles and, in the preferred embodiment, the nozzle 18 is solenoid valve operated being provided with such a valve 21 as shown best in FIG. 2. The solenoid valve 21 is of conventional construction and in the deenergized condition of the solenoid, normally interrupts the communication between the branch conduit 14 and the nozzle 18. Means are provided for opening the nozzle 18 for spraying the adjacent area and, in the specific embodiment, circuit means are provided which include main conductors 22 and branch conductors 23 for connecting the solenoids in each of the valves 21 to an associated source of electrical power 24 (not shown).

As shown in FIG. 1, the main conductors 22 are provided with suitable junction boxes 26 by means of which the main conductors 22 are connected to each of the branch conductors 23 which are connected to all of the solenoids in the valves of the nozzles connected to the branch conduits with which the respective branch conductor 23 are associated. As shown best in FIG. 2, the connection between the branch conductors 23 and the valve solenoids is facilitated by the provision of junction boxes 28.

The system of the invention includes timing means operatively associated with the nozzle opening means or solenoid actuated valves 21 for periodically opening the nozzles 18 for a selected time interval to spray a specific dosage of insecticide within the adjacent areas. Most specifically, a timer 31 of conventional construction is connected within the circuit means and more specifically, between the main conductors 22 and the associated source of electrical power 24. The setting as can be understood on the timer 31 determines when and for how long current will flow from the power source 24 to the solenoids of the valves 21. Thus, with actuation of the solenoids of the valves 21, the nozzles 18 (and 18' etc.) are actuated for a spraying operation for a selected timed interval in accordance with the precise amount of insecticide to be sprayed.

Preferably, a switch 32 is included in the circuit means for connecting the entire system to the associated source of electrical power 24. The main conduit 11 is also provided with a check valve 33 by means of which one-way flow only of the mixture from the container 13 to the branch circuits 14, 14' is obtained. Also, a valve 34 is provided in the main conduit 11 adjacent the end 11a for closing the main conduit 11 to permit connection of a full container 13 when replenishment is to be accomplished.

When the system of FIG. 1 is to be prepared for operation, and with the valve 34 in the closed position, a connection is made between the outlet 13a of a full container 13 to the adapter 12 on the main conduit 11. The bleed valve 17, 17' etc. as well as valve 34 are opened so that the insecticide-gaseous propellant mixture flows from the container through the main conduit 11 and into the branch conduits 14, 14' etc. toward the branch conduit ends 14b, 14b' respectively. With the bleed valves in the open position, air which may be entrapped within the branch conduits is therefore forced out and as soon escaping mixture is detected, the valves 17, 17' etc. are closed.

As the insecticide-gaseous propellant mixture flows out of the container 13 into the main conduit 11 and subsequently into the branch conduits 14, 14' etc. all of the conduits are filled with the mixture and the mixture in the conduits is maintained under equilibrium conditions with the mixture in the container 13. Thus, the entire system constitutes an aerosol-type container ready for operation. Under the control of the timer 31, all of the solenoids in the valve 21 are simultaneously energized to simultaneously oepn all of the valves with spraying simultaneously for the timed interval through all of the nozzles 18, 18' etc.

The circuit means incorporated in the system of the invention also preferably includes switch means such as a switch 36 in each branch circuit 23, switch 36' being provided for branch circuit 23'. A valve 37 is also provided in the branch circuit 14, valve 37' being provided in branch circuit 14' for interrupting the flow of the mixture into the conduit 14, 14' respectively. Therefore, in the event that spraying in one or more selected areas is not desired, for instance in enclosure 16, switch 36 and valve 37 are moved to the off and closed position for disconnecting conductors 23 and conduit 14 from the power source 24 and the main conduit 11 respectively thereby eliminating that branch circuit from the spraying operation while the spraying operation carried out in the other branch conduits.

The system of the invention also preferably includes at least one labyrinth trap in the interior of one or more of the conduits such as branch conduit 14 to prevent flowback of the gaseous propellant in the branch circuit. Such a trap is shown in FIG. 3 and is designated generally by the numeral 41. One or more traps may be utilized throughout the system in accordance with the design characteristics of the system.

Referring now to FIG. 3, the labyrinth trap 41 preferably includes a downwardly extending, first plate 42 secured to the upper portion of the inner wall 14c of the branch circuit 14, the plate 42 having a lower edge 42a disposed in spaced relationship with the lower portion of the branch circuit inner wall 14c. The trap 41 also includes an upwardly extending second plate 43 secured to the lower portion of the branch circuit inner wall 42c in longitudually spaced relationship with the first plate 42 and having an upper edge 43a disposed in spaced relationship with the upper portion of the branch circuit inner wall 14c.

Thus, the liquid insecticide designated by the letter I flows under the edge 42a of plate 42 and over edge 43a of plate 43 forming a seal with the plates 42, 43 to prevent flow-back of the propellant designated generally by the letter P in the branch circuit 14.

While there has been described what at present is considered to be the preferred embodiment of the invention, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the invention.