Sprinkler canister seal

An irrigation sprinkler canister seal comprising a flanged screw having a threaded rod and a circular flange extending perpendicular to the rod. The seal further includes a plug piece having a threaded bore adapted to receive the threaded rod, and further including a continuous frusto-conical surface extending around an elongate axis of the plug piece, the frusto-conical surface being configured to form a circumferentially continuous fluid seal against a cylindrical rim of a cylindrical bore.

BACKGROUND

The present invention relates to a device and method for sealing an irrigation sprinkler canister to prevent it from discharging water. Specifically, the invention relates to a device and method capable of sealing nearly all types of irrigation sprinkler canister that have been made presently available on the market.

In recent years, automatic irrigation sprinkler systems have been installed in many gardens and public spaces in the United States and other countries. During its time, the automatic irrigation sprinkler system has provided an extremely useful system for controlling the flow of water onto garden landscapes. A typical automatic irrigation sprinkler system is shown inFIG. 1in exploded condition. It includes a canister that is planted permanently in the ground and is connected via a permanently fixed underground water conduit to a system (not shown) adapted to periodically supply water under pressure to the canister. A typical sprinkler canister includes a housing102that is connected to the water supply conduit120. The housing is configured to be closed off by a cap104. The cap removably holds within the housing a pop-up riser122that is biased to a downward position by a spring124. A sprinkler nozzle126is positioned on top of the riser122. Under the pressure of water from the supply conduit, the riser is forced upwardly against the bias of the spring to elevate through a hole in the cap to a few inches above the ground, and to discharge water by sprinkling from the nozzle until such time as the water supply is automatically closed off whereupon the riser sinks back into the housing and out of view under bias of the spring. A throat piece106is generally found in each typical canister, as described in more detail below. At the time this type of irrigation system was introduced onto the market, it represented a considerable advantage over the previously applied systems that included extending a movable hose above ground onto the landscape, and irrigating the landscape by manual control of the hose. Such manual irrigation was of course labor intensive, inflexible, costly to operate, and not at all frugal in the use of water. Accordingly, manual irrigation has been largely replaced with automatic sprinkler irrigation as a definite improvement over past systems.

However, with the passage of time, and despite the more economical water usage by automatic sprinkler irrigation systems, the demand for water for irrigation has increased dramatically, while the supply of water has remained substantially constant. Consequently, it has been determined that a system even more frugal in its consumption of water than automatic sprinkler irrigation is required today for irrigating garden landscapes. One such system that has been recently developed is the drip irrigation system, or a low flow irrigation system, in which “bubbler nozzles” are located strategically in a garden landscape, all nozzles being connected via conduit to a system that supplies water under pressure to the nozzles. Instead of sprinkling water through the air onto plants, a bubbler nozzle discharges a small amount of water directly at the root of a plant which then soaks into the soil, thereby being much more accurately delivered and losing much less water to evaporation and wind dispersion than water discharged through the air onto the leaves of a plant, or even nearby the plant on the ground, as is the case with sprinkler irrigation. One aspect of introducing such a drip irrigation system to replace a sprinkler irrigation system is that the drip system may conveniently tap into an existing water distribution network comprising water conduits buried underground that has been previously installed for use with a now defunct automatic sprinkler irrigation system. However, a drip system connected in this way requires all existing sprinkler canisters to be disabled so that they do not sprinkle water through the air according to the method of an irrigation sprinkler. Thus, as ever more automatic sprinkler irrigation systems are replaced with drip or low flow irrigation systems, an ever increasing number of irrigation sprinkler canisters will require to be disabled to make way for drip irrigation technology. At present, the typically preferred way to effectively disable a sprinkler canister is for the user to expose the canister by digging a hole in the ground around the canister, and to then remove the canister from its threaded connection to the conduit water distribution system, after which the user may apply a threaded cap to the exposed conduit to permanently seal it off. After doing so, the user will close the hole and bury the capped off conduit, while disposing of the canister or placing it in storage. Over the passage of time, the location of the capped off conduit will likely be forgotten. This method suffers from a first disadvantage that disabling the canister requires a substantial amount of work to excavate and remove the canister from the ground. A second disadvantage is that, while the canister is removed from its threaded connection to the conduit, earth may fall into the temporary opening in the distribution system while the canister is removed, and this is a well known source of blockages in a subsequent drip system. A third disadvantage is that the canister is permanently removed from the water distribution system and its connection point is forgotten. Thus, if ever its temporary usage is again required, it is difficult to reinstate.

Therefore, there is a need in the art for a system and method for disabling irrigation canisters that solves the problems in the prior art. The present invention addresses these and other needs.

SUMMARY OF THE INVENTION

The sprinkler canister seal of the present invention is especially adapted and sized to fit into and seal a wide range of irrigation sprinkler canisters that have previously been made presently available on the market, each one of which is dimensioned differently. Thus, the invention relates not merely to sealing off a sprinkler canister, but also to sealing off a large proportion of all sprinkler canisters that have been made presently available on the market, regardless of size, configuration, or manufacture. To this end, a large proportion of all sprinkler canisters that have been made presently available on the market have been studied and measured, with a view to carrying out the principle of the invention.

In one preferred aspect, the invention includes a sealing system for sealing an irrigation sprinkler canister, the sealing system comprising a flanged screw having a threaded rod and a circular flange extending perpendicular to the rod. A plug piece is provided, having a threaded bore adapted to receive the threaded rod. The plug piece further includes a continuous frusto-conical surface extending around an elongate axis of the plug piece, the frusto-conical surface being configured to form a circumferentially continuous fluid seal against a cylindrical rim of a cylindrical bore. In a preferred embodiment, the frusto-conical surface is formed from ABS (or generally, acrylonitrite butadiene styrene), and has a minor diameter and a major diameter, the minor diameter is between 0.5 inches and 0.7 inches, and the major diameter is between 0.9 inches and 1.1 inches. These dimensions ensure that the frusto-conical surface will seal against the throat piece of a large proportion of all the sprinkler irrigation canisters that have been made presently available on the market. Further preferably, the threaded rod has a diameter of less than 0.5 inches, which will ensure that the rod is small enough to fit into nearly any cap of an irrigation sprinkler that has been made presently available on the market.

In another preferred aspect, the invention includes a method for sealing an irrigation sprinkler canister that is connected to a conduit of a water distribution network. The method comprises removing, from an upper surface of the canister, a cap that is attached to the canister and configured to contain within the interior of the canister a pop-up riser, an associated biasing spring, and a throat piece defining a bore for receiving the pop-up riser. A further step includes removing, from the interior of the irrigation sprinkler canister, the pop-up riser, thereby exposing an opening in the cap. A threaded rod of a flanged screw is inserted through the opening, and thence through the bore of the throat piece. The threaded rod is then inserted into a threaded bore of a plug piece having a frusto-conical surface. The flanged screw is rotated into the threaded bore, thereby drawing the plug piece towards the flanged screw, toward the throat piece, and towards the cap. The flanged screw is further rotated in relation to the plug piece until the frusto-conical surface of the plug piece penetrates and seals the bore of the throat piece, and the cap and the throat piece are captured between the plug piece and a flange of the flanged screw. The plug piece is then inserted into the canister, and the cap is re-attached to the upper surface of the canister. Under this method, the canister is sealed off against water flow from the water distribution network. In a preferred aspect, the foregoing steps are performed without removing the canister from the conduit of the water distribution network. In yet a further preferred aspect, removing the pop-up riser includes removing the associated spring.

Thus, by following this device and method, it is possible to disable a large portion of all irrigation sprinklers that have been made available on the market, while leaving such sprinklers in the earth connected to a water distribution network.

These and other advantages of the invention will become more apparent from the following detailed description thereof and the accompanying exemplary drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In order to practice the method of the present invention, a study has been conducted on a wide range of sprinkler canisters that have been made presently available on the market. As a result of this study, it has been ascertained that the majority of canisters presently available on the market include at least the following components, exemplified inFIGS. 1,2, and7. First, nearly every canister on the market includes a cylindrical housing102for enclosing some form of pop-up riser122that is spring biased124downwardly, but wherein the riser overcomes the downward bias and “pops up” when water pressure is applied to the interior of the canister. Second, nearly every canister on the market includes a removable cap104, adapted to be removably connected to the housing102. As indicated inFIG. 1, a threaded connection may be provided, or alternatively, as indicated inFIG. 2, the housing may have an external flange103that may be discontinuous around the circumference of the housing. In this configuration, the cap104may include an internal flange105that may also be discontinuous around the internal circumference of the cap, wherein the discontinuities of the housing flange and the cap flange permit the two flanges to pass through each other, whereafter rotation of the cap engages the two flanges to render the cap removably attached to the housing. The cap104defines an internal circular opening112which is sized to permit the pop up riser122to extend from and retract into the housing. Further, included in nearly every canister on the market is a throat piece106. The throat piece, or a portion of the throat piece, is used in canisters found on the market to form a seal between the cap104and the housing102and is therefore formed of a flexible elastomeric material that is suitable for forming a seal interface. The seal formed by the throat piece106between cap104and housing102is best seen as exemplified in the sectional view ofFIG. 7. Further, the throat piece is configured to stabilize the pop-up riser, which is sized to slide within a cylindrical bore111of the throat piece. The bore111of the throat piece terminates at a lower end in a circumferentially continuous rim110.

As will be appreciated, because there are large number of sprinkler canister types on the market, each with its own dimensional and geometric configuration, any single device that is designed to be capable of sealing off a large proportion of such canister types must be capable of being adapted to a major portion of the different geometries of each sprinkler canister type. The present invention is a single system specially designed to achieve this objective. Thus, the invention relates not merely to sealing off a particular sprinkler canister type, but also to being capable of sealing off a large proportion of all canister types presently available on the market, regardless of the canister's size and shape.

Therefore, referring now to the drawings, there is shown and described a preferred embodiment of a sprinkler canister seal20that includes features of the present invention. In a first aspect of the invention, the canister seal includes a plug piece22which is adapted and sized to fit into a wide range of differently shaped irrigation sprinkler canisters that have previously been made available on the market. In order to insert the plug piece22into the canister, it is first necessary to remove from the canister its pop-up riser122and preferably also the spring124that biases the riser downwardly. These two items may be stored safely in the event that it is ever desired to restore the canister to operative condition as an irrigation sprinkler, because the method of the present invention contemplates that any step disabling the canister should be a fully reversible step. In a second aspect of the invention, the canister seal includes a flanged screw24whose purpose is to pull the plug piece22upwardly toward the flanged screw once the plug piece is installed inside the housing102of the canister.

As seen in the figures, the plug piece22includes a frusto-conical portion that defines a frusto-conical surface30extending symmetrically around the circumference of the plug piece and inclined at an angle θ to the vertical axis of the plug piece, the angle being preferably between 30 and 60 degrees. Consequently, the frusto-conical surface30has a minor diameter D1at its upper end and a major diameter D2at its lower end, as seen inFIGS. 3 and 5. Preferably, the minor diameter is between 0.5 inches and 0.7 inches, and the major diameter is between 0.9 inches and 1.1 inches for reasons stated below. Also preferably, the frusto-conical surface is formed of a flexible ABS or similar material, capable of slight deformation under pressure. By extension, the entire plug piece22is preferably mold cast as one piece from the same type of material. Further features of the plug piece22include an internal threaded bore32, extending from the top of the plug piece downwardly along the central axis of the plug piece and adapted to receive a threaded rod34on the flanged screw24. Further included on the plug piece are tabs31extending from the lower surface of the plug configured to facilitate a user to apply a rotational torque to the plug.

The flanged screw24is configured to engage with the plug piece22via threaded engagement between the threaded bore32of the plug piece, and the threaded rod34of the flanged screw. The flanged screw further includes a relatively broad flange36which may include finger tabs38configured to permit a user to apply rotational torque to the flanged screw24. The outside diameter D4of the flange36is preferably sufficient to securely span across the largest cap104on any of the commercially available sprinkler canisters presently available on the market, and in a preferred embodiment is not less than 2 inches.

The diameter D3of the threaded rod34is preferably selected to be less than 0.5 inches, so that it will tend to pass through the smallest opening112of a cap104on any one of the commercially available sprinkler canisters presently available on the market. Further, the minor diameter D1of the frusto-conical surface is selected with the dimensions as set forth above so that it will preferably engage with the smallest diameter of the throat piece106on any of the commercially available sprinkler canisters presently available on the market. And yet further, the major diameter D2of the frusto-conical surface is selected with the dimensions set forth above so that it will preferably engage with the largest diameter of the throat piece106on any of the commercially available sprinkler canisters presently available on the market. It will be appreciated that the conical feature of the surface30adds mechanical advantage to its ability to provide a seal, as explained below.

In use, the irrigation canister seal20is applied as follows. The user approaches an existing irrigation sprinkler canister lodged in the earth that is connected to a conduit of a water distribution system, and clears away a few centimeters of earth surrounding the canister to expose the upper surface of the canister. Preferably, the user does not remove the canister seal from its connection to the conduit of a water distribution system, to conserve on the amount of work necessary to carry out the invention. Next, the upper cap104is removed from the housing102of the canister along with the pop up riser, the biasing spring, the throat piece106and any other portion of the interior of the housing. The pop up riser, and preferably the biasing spring, are discarded, while storing the same in the event it should be needed at a later date. Then, the threaded rod34of a flanged screw36is inserted through the opening112of the cap, the throat piece106is installed and any other portion required to complete a water tight fit such as flanged cylinder108over the threaded rod. Finally the plug piece22is installed on the tip of the threaded rod. By rotating the plug piece22in relation to the flanged screw24, the plug piece22is drawn up towards the cap104, and the conical surface30of the plug piece is compressed onto the bore of the throat piece to seal against the lower rim110of the throat piece106to form a circumferentially continuous and water tight seal against the throat piece as seen inFIG. 7. It will be appreciated that the conical aspect of the surface30provides a mechanical advantage, by which the tension force in the rod is leveraged to increase the radially outward force of the surface30against the rim110to form the seal. Then, the user holds the resulting assembly, including the cap104, the throat piece106, the plug piece22, and the flanged screw24, over the housing102of the canister, and he inserts the plug piece of the assembly into the housing102. The internal flange of the cap104is engaged with the external flange of the housing102, the cap is rotated to lock the cap onto the housing to reinstate the seal between the cap and the housing, and the canister is thereby sealed against water flow, as exemplified inFIG. 7, with an additional seal being formed between the plug piece22and the rim110of the throat piece106.

The canister is thus taken out of service, but at a minimum its housing102and cap104are left in place in the earth connected to a conduit (not shown) in the water distribution network. Should it ever be desirable to reinstate a functioning irrigation sprinkler at that location, the reverse steps are easy to perform in order to reinstate an operable sprinkler.

Thus, the irrigation canister seal of the present invention provides a novel and advantageous structure for sealing off a large proportion of known irrigation sprinkler canisters, presently on the market, against water flow. The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, while the scope of the invention is set forth in the claims that follow.