Adjustable sprinkler head riser with cushioning region

An apparatus for changing a length of a pipe, the pipe including first and second pipe portions each having an interior, includes a cylinder having a first end wall and an open end, the cylinder being connectable to the first pipe portion. The apparatus also includes a piston having a second end wall, the piston being receivable in slidable and sealable engagement with the cylinder, the piston being connectable to the second pipe portion, wherein the cylinder and the second end wall define a chamber physically isolated from the interiors of the first and second pipe portions, the chamber being adapted to receive a control fluid for displacing the piston relative to the cylinder to vary a distance between the first and second pipe portions while permitting fluid communication between the first and second pipe portions, the chamber including a cushioning region in communication with the chamber.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates generally to adjusting the length of a pipe, and more particularly, to an apparatus for adjusting the height of a sprinkler head riser.

2. Description of Related Art

In golf courses, lawns, and other grass covered areas, frequent watering is required to maintain the area in an esthetically pleasing and healthy condition. It is well known in the art that a network of distributed pipes and sprinkler head attachments may be provided underneath the surface of the ground to provide the required watering. Such an underground system is not visible when not in use, and does not require set up for each watering, but merely requires activation.

In the field of golf course design, in-ground sprinkler heads and their associated network of piping are common. The use of in-ground sprinkler systems in golf courses, however, presents unique design requirements due to the nature of the game of golf which is played around such sprinkler heads.

For example, the top surface of the sprinkler head should preferably be as level with the surrounding ground as possible. Should the sprinkler head extend above the surface of the surrounding ground, it may pose a hindrance or obstruction to any golf ball which may come into contact or close proximity to the sprinkler head. Conversely, should the sprinkler head be at a position below the surface of the surrounding ground, the sprinkler head may create a depression in the playing surface of the golf course with the result that golf balls tend to roll into such a depression. Therefore, should the top surface of the sprinkler head assembly not be flush with the surrounding ground, the sprinkler may serve to reduce the enjoyment of the golf players, due to the above-mentioned hindrances, thereby reducing the desirability of the course.

Also, a frequent activity of golf course maintenance is to distribute sand or other soil material across the top surface of the golf course. This addition of soil to the golf course may serve to reduce the height of the top surface of the sprinkler head relative to the surrounding ground as the additional soil is added. Therefore, it is frequently necessary to increase the height of the sprinkler head relative to the distribution piping network so as to maintain the top surface of the sprinkler head flush with the surrounding ground. In some arrangements, this activity may require excavation of the sprinklers so as to adjust the height of the sprinkler head relative to the water supply lines. This is commonly accomplished by adjusting the angle of a conventional swing joint. It will be appreciated that such an activity of excavating and adjusting the height of each individual sprinkler head on a golf course is a time consuming and expensive activity. This periodic excavation of the sprinkler heads, also serves to render the immediate vicinity around the sprinkler head unplayable for a certain period of time while the necessary adjustments are being made.

In addition, any grassy surface such as a golf course is required to be cut periodically through the use of a mower. On a property such as a golf course, such a mower may be a large piece of equipment having a substantial weight. During the process of mowing the golf course, the wheels of such a mower may ride over top of a sprinkler in the ground. This will transfer the large weight of mower to the sprinkler head and any equipment under it for a short period of time. The weight from mowers, or from other equipment or other heavy objects, may cause damage (such as a crack or another source of a leak, for example) to the sprinkler head, or to a pipe for supplying water to the sprinkler head. This damage may require repair, and may cause water to leak and be wasted. Also, leaking water may cause damage to surrounding terrain.

Many previous arrangements require the sprinkler head riser assembly to be excavated to access the adjusting means which is buried. In addition, many previous attempts have relied upon threading or ridges between a pair of telescoping bodies to adjust a height of a sprinkler head. These attempts have relied on a fixed structure to extend the riser assembly and resist the compressive forces of the mower. Disadvantageously, such mechanisms may become damaged and jammed should the applied weight of the mower become too great. In addition, such mechanisms have a tendency to become jammed by the inclusion of dirt and other contaminants.

Other previous attempts have relied upon a biasing element securing a connection between two telescoping members. These mechanisms rely on a frictional or non-returning engagement between the biasing element and the telescoping members to secure relative position between them. These mechanisms have the disadvantage of not enabling the height of the sprinkler head to return to a set position after been forcibly compressed, for example, by the weight of a mower.

SUMMARY OF THE INVENTION

In accordance with one aspect, there is provided an apparatus for changing a length of a pipe, the pipe including first and second pipe portions each having an interior. The apparatus includes a cylinder having a first end wall and an open end, the cylinder being connectable to the first pipe portion. The apparatus also includes a piston having a second end wall, the piston being receivable in slidable and sealable engagement with the cylinder, the piston being connectable to the second pipe portion, wherein the cylinder and the second end wall define a chamber physically isolated from the interiors of the first and second pipe portions, the chamber being adapted to receive a control fluid for displacing the piston relative to the cylinder to vary a distance between the first and second pipe portions while permitting fluid communication between the first and second pipe portions, the chamber including a cushioning region in communication with the chamber.

The cushioning region may include at least one groove formed in at least one wall of the chamber to increase the volume of the chamber.

The cushioning region may include an annular recess in the second end wall.

DETAILED DESCRIPTION

First Embodiment

Referring toFIG. 1, an in-ground sprinkler system including an adjustable sprinkler head riser assembly14according to a first embodiment of the present invention is shown generally at10. The in-ground sprinkler system comprises a sprinkler head assembly12, a sprinkler head riser assembly14, a swing joint16and a water supply pipe18. The sprinkler head assembly12, swing joint16and water supply pipe18are conventional in the art.

The swing joint16comprises a tubular body having first and second pivotable joints that enables the height of the sprinkler head to be adjusted during installation by pivoting the swing arm assembly about the pivot connected to the water supply main. The adjustable sprinkler head riser assembly14may be threadably attached to the swing joint16. The sprinkler head assembly12may be threadably attached to the sprinkler head riser assembly. Accordingly, the swing joint16and sprinkler head riser assembly14form a continuous water conduit path between the water supply pipe18and the sprinkler head assembly12.

In a conventional in-ground sprinkler system, the height of the sprinkler head may be adjusted at the time of installation by means of the swing joint16. According to the present invention, the height of the sprinkler head may additionally be adjusted after installation by means of the adjustable sprinkler head riser assembly14. It will be appreciated that although the current embodiment of the present invention includes a swing joint16, such an assembly may not be necessary and the sprinkler head riser assembly14may be connected directly to the water supply pipe18.

Referring toFIG. 2, a cross-sectional view of an assembled adjustable sprinkler head riser assembly14in accordance with the first embodiment of the invention is shown. The sprinkler head riser assembly14comprises a substantially elongate extendible tubular body having first and second opposite ends20and22respectively. The sprinkler head riser assembly14comprises a cylinder portion30, a piston portion80, and a guard ring120.

Referring toFIG. 3, a detail cross-sectional view of the cylinder portion of the first embodiment is shown generally at30. The cylinder portion30is comprised of an elongated cylindrical first pipe portion32surrounded by an outer tubular shell34. An end wall36connects shell34to pipe portion32. The first pipe portion32comprises an elongated cylindrical body having an axis38and includes the first end20of the sprinkler head riser assembly14. The first pipe portion32also includes an outer surface42, an inner surface40forming a bore41therethrough, and external threading44at the first end20. It will be appreciated that although external threading44is shown in the attached figures, other methods also be used to connect the sprinkler head riser assembly14to the sprinkler head assembly12. Such alternative connection means may include but are not limited to, connecting the sprinkler head riser assembly to the sprinkler head assembly by means of glue, solder, or a compression fitting. In addition internal threading on the cylinder portion may connect to external threading on the sprinkler head assembly. The first pipe portion32may also include one or more internal grooves46in the inner surface40at a second end48each adapted to receive an O-ring50.

The shell34comprises an elongated cylindrical body co-axially aligned with the first pipe portion32about axis38. The shell34includes an inner surface52and an outer surface54. The outer surface54may include external threading56and a set screw hole58.

The end wall36comprises an annular disc having a substantially planar shape between first and second radii defining inner and outer edges60and62, respectively. End wall36may be perpendicular to the axis38and includes an inner surface64and an outer surface66. The end wall is connected at its inner edge to the first pipe portion32and at its outer edge to the shell34. The outer surface42of the pipe portion32, the inner surface52of the shell34and the inner surface64of the end wall36define an annular cavity68having an open lower end70. The end wall36may also include a bore72therethrough so as to permit the introduction of a control fluid into the cavity68. The bore72may be threaded to accept a correspondingly threaded first fluid control supply tube (140inFIG. 1).

Referring toFIG. 4, a cross-sectional view of the piston portion80of the first embodiment is shown. The piston body comprises a second pipe portion82surrounded by an annular piston84. The second pipe portion82comprises an elongate tubular body having a free first end86. The opposite end of the second pipe portion merges with the piston84to define the second end22of the sprinkler head riser assembly14. The second pipe portion82includes an outer surface94and an inner surface96defining a bore98therethrough. Bore98adjacent second end22may include internal threading88. It will be appreciated that although internal threading88is shown in the attached figures, other methods may also be used to connect the sprinkler head riser assembly to the swing joint16or water supply pipe18. Such alternative connection means may include but are not limited to, connecting the sprinkler head riser assembly to the sprinkler head assembly by means of glue, solder, or a compression fitting. In addition external threading on the piston portion may connect to internal threading on the sprinkler head assembly.

The piston84comprises a piston head100and a connecting portion102. The piston head100comprises an annular body aligned with axis38. The piston head100has an annular outer surface104, an annular inner surface106, and a generally disk-shaped end surface108. The outer surface104may include a circular groove110adapted to receive an outer O-ring112. The piston head100is connected to the second end22by piston connecting portion102. Piston connecting portion102consists of an elongated tubular body extending between the piston head100and the second end22. Piston connecting portion102also includes an outer cylindrical surface118having a central axis co-axial with axis38. Preferably, the end surface108is not flat, but rather defines at least one recess and/or at least one projection, for defining a cushioning region. In the illustrated embodiment, the end surface108defines an annular recess134(which may also be termed an “annular groove”).

Referring toFIG. 5, a cross-sectional view of the guard ring120of the first embodiment is shown. The guard ring120comprises an annular ring122having an axis common with axis38, and an internal lower flange124. The internal flange has an inner edge126which defines an opening128. The opening128has a radius matched to the radius of the outer cylindrical surface118of the piston connecting portion102. The guard ring120also includes internal threading130operable to engage the threading56on the cylinder body, and a set screw hole132.

As shown inFIG. 2, piston portion80is received within cylinder portion30such that the piston84is received in slidable and sealable engagement within the cavity68, and the second pipe portion82is received within the first pipe portion32. All parts are co-axially aligned with common axis38. The piston84is received within the cavity68such that outer surface104slidably engages with inner surface52of the shell34and the inner surface106slidably engages with outer surface42of the first pipe portion32. O-ring112preferably serves to seal the connection between the piston and the cylinder. As assembled in this manner, a first sealed control chamber74is formed between the cylinder and the piston head100. Specifically, inner surface52of shell34, outer surface42of the first pipe portion32, inner surface64of end wall36, and end surface108of the piston head100form the first sealed control chamber74. The first sealed control chamber74has a volume, which changes as the piston84is displaced within the cylinder along axis38.

Guard ring120may then be secured to the external threading56on the shell34so as to enclose the bottom end of the cylinder. When the guard ring120is secured to the shell, the opening128of the guard ring may closely engage upon the outer cylindrical surface118of the piston connecting portion102so as to prevent the fouling of the riser apparatus by its surrounding soil, water and other contaminants. The guard ring120may also be secured to the shell by means of a set screw being passed through set screw hole132of the guard ring and set screw hole58of the shell. In addition, it will be appreciated that set screw hole58or an additional hole in the shell may be used as a relief port to the cylinder when the sprinkler head riser assembly is extended. The set screw hole may be contained within the guard ring120or may optionally include an expellable plug that may be displaced under a predetermined pressure in the cylinder so as to relieve the pressure in the cylinder.

It will be appreciated that the cylinder and piston arrangement as described above is not necessarily limited to an annular arrangement. Other cylinder and piston arrangements may be used in addition to those specifically discussed above to achieve the same result. Specifically, the cylinder and piston may have a circular shape and be disposed adjacent to the first and second pipe portions32and82respectively. In such an arrangement, the adjacent cylinder may be connected to the first pipe portion32and the enclosed piston connected to the second pipe portion82. In addition, the apparatus may comprise a plurality of cylinders and associated pistons disposed around the first and second pipe portions. Such a plurality of cylinders and pistons may be arranged in an irregular or regular-radial peripheral array pattern around the first and second pipe portions32and82respectively. It will also be appreciated that in other embodiments, the first and second pipe portions32and82respectively need not be in axial alignment.

The sprinkler head riser assembly14according to the first embodiment may be installed as part of an underground sprinkler system as shown inFIG. 1. The underground sprinkler system may comprise a water supply pipe18, a swing joint16, and a sprinkler head assembly12. Water is supplied to the system by the water supply pipe18. This water is passed through the swing joint16and into the bore98at the second end22of the sprinkler head riser assembly14. The water then passes through the bore41to the first end20and thereafter into the sprinkler head assembly12.

Referring toFIGS. 1 and 2, a first control fluid supply tube140may be connected to the bore72in the sprinkler head riser apparatus. The first control fluid supply tube140comprises an elongated tube connectable to bore72to communicate the first sealed control chamber74with a control fluid source. The first control fluid supply tube includes a free end144disposed adjacent to the top surface146of the sprinkler head. The first control fluid supply tube may be free floating or secured to the sprinkler head assembly for the majority of its length. The first control fluid supply tube may also be incorporated into the sprinkler head assembly.

In operation, a user may connect a fluid source and pump (not shown) to the free end144of the first control fluid supply tube140as shown inFIG. 1. The pump is operable to supply a control fluid under pressure to the first control fluid supply tube140. The first control fluid supply tube140then supplies the fluid through its second end142which is connected to the bore72in the sprinkler head riser assembly.

In such a manner, the user may increase or decrease the amount of control fluid in the first sealed control chamber74. Varying the amount of control fluid within the first sealed control chamber74will serve to displace the piston84relative to the cylinder30. As the piston84is displaced relative to the cylinder30, the distance between the first and second ends20and22, respectively, of the sprinkler head riser assembly14is varied.

The control fluid may include but is not limited to hydraulic fluid, water or any other suitable fluid. It will be preferable to use a control fluid that is an environmentally safe, viscous fluid. Examples of such fluids may include vegetable and grain based oils and greases as well as environmentally safe anti-freeze solutions. In addition, water may be used as a control fluid in locations where there is no risk of freezing.

Alternatively, a compressible control fluid, such as air, for example, may be desirable so that forces exerted on the top surface146of the sprinkler head by a mower wheel, or by any other heavy object, may be absorbed by compression of the compressible control fluid in the first sealed control chamber74. It will be appreciated that the control fluid in the first sealed control chamber74may also include a combination of fluids, such as air and water, for example.

Accordingly, the height of the top surface146of the sprinkler head assembly may be adjusted relative to the water supply pipe18from which it is supplied. In this way, the user may adjust the height of the sprinkler head relative to the surrounding ground to account for changes in settling soil as well as the addition of additional soil over time to maintain the top surface146of the sprinkler head at a desired height.

When force exerted by a mower wheel, or by any other heavy object, is absorbed by compression of a compressible control fluid in the first sealed control chamber74, a resulting transmitted force exerted by the adjustable sprinkler head riser assembly14on the water supply pipe18may be reduced or eliminated, and thus risk of damage to the water supply pipe18from mower wheels or other heavy objects may advantageously be reduced. Furthermore, when force is absorbed by compression of the control fluid in the first sealed control chamber74, the swing joint16may not be required to absorb such forces. Instead, the adjustable sprinkler head riser assembly14may be coupled directly to the water supply pipe18, for example, which may advantageously reduce cost of the system10.

Preferably, the control fluid that is introduced into the first sealed control chamber74can enter a cushioning region that is defined by the end surface108and in communication with the first sealed control chamber74, such as the annular recess134, for example. Therefore, when the control fluid in the first sealed control chamber74includes a compressible control fluid, and when a mower wheel or another heavy object exerts a force on the top surface146of the sprinkler head, for example, the annular recess134(or any other cushioning region that is defined by the end surface108) may receive a portion of the control fluid in the first sealed control chamber74. Thus, the annular recess134may advantageously enable a greater absorption of a force that is exerted on the top surface146of the sprinkler head by a mower wheel, or by any other heavy object, for example.

It will be appreciated that the end surface108may define a cushioning region other than the annular recess134, and may also define a plurality of cushioning regions. For example, the end surface108may define one or more bores, grooves, channels, and/or other cavities of various configurations. Alternatively, the end surface108may define one or more projections to define a cushioning region when the one or more projections abut a portion of the inner surface64. More generally, any non-flat end surface108may define one or more cushioning regions for receiving control fluid in the first sealed control chamber74, to enable a greater absorption of a force exerted on the top surface146of the sprinkler head by the control fluid. Furthermore, in alternative embodiments, a cushioning region may additionally or alternatively be defined elsewhere in the first sealed control chamber74, such as by the inner surface64, for example.

It will further be appreciated that although as described above, the sprinkler head riser assembly14and the sprinkler head assembly12are described as separate components, the sprinkler head riser apparatus may be formed including the sprinkler head assembly. According to such an embodiment, the sprinkler head will be formed as continuous with the first pipe portion. In such an alternative embodiment, the fluid may be supplied to the first sealed control chamber74through a supply tube internal to the sprinkler head. In some such alternative embodiments the end wall36may be disposed close to the surface of the sprinkler head and therefore the fluid source and pump may be connected directly to the bore72.

Second Embodiment

Referring toFIG. 6, a cross-sectional view of an assembled adjustable sprinkler head riser apparatus in accordance with a second embodiment of the invention is shown generally at200. The sprinkler head riser apparatus200includes a cylinder portion210, a piston portion240, and a guard ring280.

Referring toFIG. 7, a detail cross-sectional view of the cylinder portion of the second embodiment is shown generally at210. The cylinder portion210includes an elongated cylindrical first pipe portion212surrounded by an outer tubular shell218. An end wall220connects the outer tubular shell218to the first pipe portion212. The first pipe portion212includes an outer surface214and an inner surface216, defining a bore217therethrough. The first pipe portion212also includes external threading222operably configured for coupling the cylinder portion210to the sprinkler head assembly12(FIG. 1). However, it will be appreciated that other methods, such as glue, solder, a compression fitting, or internal threading, may be used for coupling the cylinder portion210to the sprinkler head assembly12.

The first pipe portion212includes one or more grooves224in the outer surface214, each operably configured to receive an O-ring226. It has been found that in some manufacturing processes, it is easier to create the grooves224in the outer surface214of the first pipe portion212than it is to create internal grooves46in the inner surface40of the first pipe portion32of the first embodiment. It has also been found that in some manufacturing processes, it is easier to create the grooves224in the outer surface214of the first pipe portion212if the grooves224are made on a portion of the first pipe portion212that extends farther from the end wall220than the outer tubular shell218, as shown inFIG. 7.

The outer tubular shell218includes an elongated cylindrical body having an inner surface228, an outer surface230, and external threading232. In the second embodiment, the outer tubular shell218does not include a set screw hole58. The end wall220includes an inner surface221and a bore236, and is substantially similar to the end wall36of the first embodiment. The outer surface214of the first pipe portion212, the inner surface228of the outer tubular shell218, and the inner surface221of the end wall220define a cavity234.

Referring toFIG. 8, a cross-sectional view of the piston portion of the second embodiment is shown generally at240. The piston portion240includes a second pipe portion242coupled to an annular piston250. The second pipe portion240includes an inner surface244defining a bore248therethrough. The inner surface244includes internal threading246operably configured for coupling the piston portion240to the swing joint16or to the water supply pipe18(FIG. 1). It will be appreciated that other methods, such as glue, solder, a compression fitting, or external threading, may be used for coupling the piston portion240to the swing joint16or to the water supply pipe18.

In the second embodiment, the second pipe portion242does not extend substantially along the length of the annular piston250. It has been found that in some manufacturing processes, manufacturing the piston portion240is easier than manufacturing a piston portion wherein the second pipe portion extends substantially along the length of the annular piston.

In the second embodiment, the annular piston250includes an annular outer surface251, an annular inner surface252, and a piston head254. The piston head254includes an annular outer surface256and a generally disk-shaped end surface258. The outer surface256includes a circular groove260operably configured for receiving an outer O-ring262, and the inner surface252includes a circular groove264operably configured for receiving an inner O-ring266. However, in other embodiments, the circular grooves260and264and the O-rings262and266may be omitted. In particular, the circular groove264and the O-ring266may be omitted because sealing between the outer surface214and the annular inner surface252is provided by the O-ring226described above.

Preferably, the end surface258is not flat, but rather defines at least one recess and/or at least one projection, for defining a cushioning region, as described above with respect to the end surface108of the first embodiment. In the illustrated embodiment, the end surface258defines an annular recess299(which may also be termed an “annular groove”), but the annular recess or groove299is illustrated by way of example only. As described above with respect to the end surface108of the first embodiment, any non-flat end surface258, or any other surface defining the first fluid chamber297shown inFIG. 6, may define one or more cushioning regions for receiving control fluid.

Referring toFIG. 9, a cross-sectional view of the guard ring of the second embodiment is shown generally at280. The guard ring280includes an annular ring282, and an internal lower flange284. The internal lower flange284has an inner edge286that defines an opening288having a suitable radius for the annular piston250(FIG. 8) to pass therethrough such that the annular outer surface251may be in slidable and sealable engagement with the inner edge286. The inner edge286includes a circular groove290operably configured for receiving an O-ring292. The guard ring280also includes internal threading294operably configured for engaging the external threading232of the cylinder portion210(FIG. 7), but it will be appreciated that other methods, such as glue or solder, may be used for coupling the cylinder portion210to the guard ring280. In the second embodiment, the guard ring280does not include a set screw hole132. However, in the second embodiment, the guard ring280includes a bore296therethrough.

Referring back toFIG. 6, the annular piston250of the piston portion240is received within the cavity234of the cylinder portion210such that the outer O-ring262and the annular outer surface256of the piston head254are in slidable and sealable engagement with the inner surface228of the outer tubular shell218, and the inner O-ring266and the annular inner surface252of the annular piston250are in slidable and sealable engagement with the O-ring226and the outer surface214of the first pipe portion212. Thus, a first sealed control fluid chamber297is formed between the piston head254and the end wall220, and the bores217and248form a continuous sealed water passage through the sprinkler head riser apparatus200. The guard ring280may be coupled to the cylinder portion210such that the annular outer surface251of the annular piston250is in slidable and sealable engagement with the O-ring292and the inner edge286of the internal lower flange284of the guard ring280. Although the first and second pipe portions212and242respectively are shown in axial alignment, it will be appreciated that the first and second pipe portions need not be in axial alignment.

The result of this assembly, and the operation of the sprinkler head riser apparatus200, are substantially as described above with reference to the first embodiment. However, in the second embodiment, the annular piston250, the outer tubular shell218, and the guard ring280define a second sealed control fluid chamber298. A second fluid control supply tube (not shown) may be coupled to the bore296, so that a user may supply a control fluid under pressure to the second sealed control fluid chamber298. Thus, in the second embodiment, a user may supply a control fluid under pressure independently through the bores236and296to “double acting” control fluid chambers297and298respectively, thereby exerting complementary forces on the piston portion240relative to the cylinder portion210.

Third Embodiment

Referring toFIG. 10, a sprinkler head riser apparatus in accordance with a third embodiment of the invention is shown generally at300. The sprinkler head riser apparatus300includes a cylinder portion302, a piston portion304, and a guard ring310. The piston portion304includes a piston head306, and the piston head306includes a disk-shaped lower surface308. The guard ring310includes an internal lower flange312. The sprinkler head riser apparatus300includes the elements of the first embodiment or the second embodiment, and further includes a spring314for urging the annular lower surface308away from the internal lower flange312. The spring314may advantageously resist a potential tendency for water pressure in the sealed water passage to urge the annular lower surface308towards the internal lower flange312. However, in other embodiments, the spring314may urge the annular lower surface308towards the internal lower flange312.

Preferably, the piston head306has an end surface316that is not flat, but rather defines at least one recess and/or at least one projection, for defining a cushioning region, as described above with respect to the end surface108of the first embodiment. In the illustrated embodiment, the end surface316defines an annular recess318(which may also be termed an “annular groove”), but the annular recess or groove318is illustrated by way of example only. As described above with respect to the end surface108of the first embodiment, any non-flat end surface316or other surface may define one or more cushioning regions for receiving control fluid.