Description:
This invention relates to sprinklers and more particularly to sprinklers of the pop-up type.
Pop-up sprinklers are well known and are used extensively in in-ground sprinkler system installations. The usual pop-up sprinkler includes a housing assembly adapted to be stationarily mounted within the ground and to be connected at its lower end with an in-ground supply pipe through which a controllable source of water under pressure is communicated with the housing assembly. A sprinkler head assembly normally disposed in a retracted storage position within the housing assembly is adapted to extend into an operative position in response to the communication of the water source. In many instances coil spring means is provided between the two assemblies to insure that the sprinkler head assembly retracts into its storage position when the communication of the water source is closed off.
One source of difficulty encountered in the cyclical operation of these sprinklers resides in the sealing functions provided. Various different sealing constructions have been proposed in the prior art. See for example U.S. Pat. Nos. 2,909,325; 3,335,959; 3,434,664; 3,454,225; 3,724,757; and 3,713,584.
An object of the present invention is to provide a pop-up sprinkler having an improved one-piece seal capable of performing a multiplicity of essential and desirable functions in the various stages of cyclical operation of the sprinkler. In accordance with the principles of the present invention this objective is obtained by providing a one-piece annular seal having means for performing the following specified functions: (1) providing a static seal between separable parts of the housing assembly, (2) providing a spring seat for one end of the retraction spring, (3) providing a pressure responsive leakage path between the housing assembly and sprinkler head assembly for passage of water upwardly and outwardly therethrough when the water source is initially communicated with the housing assembly to thereby remove contiguous debris and prevent the passage of debris downwardly therethrough during the extending movement of the sprinkler head assembly, (4) provide an operative seal between the housing assembly and the sprinkler head assembly when the latter is in its extended operative position and (5) provide a wiping and centering action on the sprinkler head assembly during the retracting movement thereof.
Another object of the present invention is the provision of a pop-up sprinkler of the type described which is simple in construction, effective in operation and economical to manufacture.
These and other objects of the present invention will become more apparent during the course of the following detailed description and appended claims.
The invention may best be understood with reference to the accompanying drawings wherein an illustrative embodiment is shown.
In the drawings:
FIG. 1 is a vertical sectional view of a pop-up sprinkler embodying the principles of the present invention showing the same in its retracted storage position installed in the ground;
FIG. 2 is a sectional view taken along the line 2--2 of FIG. 1;
FIG. 3 is an enlarged fragmentary view of the seal area of the pop-up sprinkler illustrating the function thereof during extending movement of the sprinkler head assembly;
FIG. 4 is a view similar to FIG. 3 illustrating the function of the seal when the sprinkler head is in its extended operative position; and
FIG. 5 is a view similar to FIG. 3 illustrating the function of the seal during the retracting movement of the sprinkler head assembly.
Referring now more particularly to the drawings, there is shown in FIG. 1 thereof a pop-up sprinkler, generally indicated at 10, embodying the principles of the present invention. The pop-up sprinkler 10 includes a housing assembly, generally indicated at 12, which is adapted to be installed within the ground, as shown in FIG. 1, so that its upper end is substantially level with the surface of the ground and extends downwardly therefrom. The lower end of the housing assembly 12 is connected to a supply pipe 13 through which a controllable source of water under pressure is communicated with the housing assembly 12. A sprinkler head assembly, generally indicated at 14, normally disposed in a retracted storage position within the housing assembly, as shown in FIG. 1, is adapted to extend into an operative position in response to the communication of the water source. A coil spring 16 is provided between the two assemblies to insure that the sprinkler head assembly 14 retracts into its storage position when the communication of the water source is closed off. The pop-up sprinkler 10 also includes a multiple purpose one-piece seal, generally indicated at 18, which is cooperatively engaged with the housing assembly 12, sprinkler head assembly 14, and coil spring 16.
It will be understood that the housing assembly 12 may assume any desired configuration. As shown, the housing assembly 12 includes a first housing member 20 of generally cup-shaped configuration, preferably molded of a suitable material such as plastic or the like. The first housing member has a lower end portion formed with an interiorly threaded tubular section 22 for connection with the supply pipe 13 as shown and an open upper end portion terminating in an upwardly facing annular end surface 24 which, as shown, is a flat annular surface disposed in a radial plane with respect to the vertical axis of the housing member 20. The housing assembly 12 also includes a second housing member 26 which includes a tubular sleeve portion formed with interior threads 28 adapted to threadedly engage cooperating exterior threads formed on the upper end portion of the first housing member 20. The second housing member 20 also includes a radially inwardly extending flange portion which terminates in a generally cylindrical interior surface 30. The flange portion of the member 26 includes a downwardly facing surface 32 extending radially from the sleeve portion to the cylindrical surface 30. As shown, the surface 32 is a flat annular surface disposed in a radial plane.
The sprinkler head assembly 14 may likewise assume any desirable configuration. As shown, the sprinkler head assembly 14 is of the spray head type although it will be understood that other known types are contemplated, such as rotaries, etc. A part-circle spray head 34 is threadedly mounted within an interiorly threaded upper end wall 36 of a vertically movable tubular member 38. The movable member 38 includes a cylindrical exterior periphery 40 of a size slightly less than the interior cylindrical surface 30 which extends downwardly from the spray head 34 throughout a major portion of the member and terminates in a radially outwardly extending upwardly facing surface 42. The surface 42 is formed on an enlarged open lower end portion 44 of the member 38 which terminates in a radially outwardly extending flange 46. The upwardly facing surface of the flange provides a lower seat for the spring 16. It will be understood that a separate annular cushioning member may be utilized as the seat defining means, if desired, rather than the integral surface of the flange 46.
Since the particular type of head shown is a part-circle spray head the fixed angular position of which determine the location of the pattern area, it is important to insure that the latter and, hence the movable member 38 which fixedly carries the same, does not move angularly during its vertical movement. To this end, a plurality of circumferentially spaced guide lugs 48 are integrally formed on the outer periphery of the flange 46. As best shown in FIG. 2, one or more of the guide lugs 48 are between cooperating pairs of axially extending guide ribs 50 formed on the interior periphery of the first housing member 20. It will be understood that while the lug and guide rib arrangement prevents angular or rotational movement of the spray head such as an arrangement is not essential in many types of heads other than the part-circle spray head 34 as shown.
As previously indicated, the present invention is particularly concerned with the multiple-purpose one-piece seal 18. The seal 18 is preferably molded of a suitable moldable sealing material such as resinous or rubber materials, a preferred example being a polyester elastomer produced by E. I. duPont deNemours & Co., Inc. under the trade name HYTRIL. Another exemplary material is urethane.
As best shown in FIGS. 3-5, the seal includes a radially outer portion 52 disposed between and forming a static seal with the first member end surface 24 and the flat range portion downwardly facing surface 32. An intermediate portion 54 is disposed in engagement with the surface 32 and defines a downwardly facing upper spring seat receiving the upper end of the coil spring 18. As shown, in order to center the spring end on the seat, the seal includes an annular depending ridge or projection 56. The radial inner portion of the seal 18 provides an annular flexible lip 58 which extends upwardly within the flange portion cylindrical surface 30 and inwardly into engagement with the cylindrical periphery 40 of the movable member 38. A downwardly facing annular surface 60 is also provided on the radially inward portion of the seal which is engageable with the upwardly facing surface 42 of the movable member 38 when the latter reaches its extended position.
The sprinkler head assembly is shown in FIG. 1 in its retracted inoperative position installed within the ground and connected with an inlet pipe. As shown, a controllable source of water under pressure has been shut off from communication with the inlet pipe so that the spring 16 resiliently biases the member 38 into the retracted position shown. In this position the outer portion 52 of the seal 18 forms a static seal between the housing member 20 and 26 by engagement with surfaces 24 and 32 thereof respectively. This static seal remains throughout the cyclic operation of the sprinkler. The intermediate portion 54 provides a spring seat for the upper end of the spring 16 with the annular projection providing a centering function on the spring. The lip 58 extends upwardly within the interior peripheral surface 30 into engagement with the exterior peripheral surface 40 thus providing a resilient centering action on the retracted housing member and a seal preventing debris from entering the interior of the sprinkler head.
When the controllable source of water under pressure is turned on, this water is communicated with the bottom interior of fixed housing member 20 by the inlet pipe. As the interior of the sprinkler housing member fills up with water, the air is displaced outwardly through the spray head 34. When the water initially reaches the seal 18, its pressure acting on the interior of the lip 58 tends to deflect the same permitting an upward water leakage thereby which positively tends to prevent debris from entering the interior of the housing member. When the water has completely filled the housing members 20 and 38, the differential pressure thereof acts upon the movable housing member 14 as a piston with the fixed housing member 12 acting as a cylinder and the lip acting as an annular seal therebetween to establish an upward force on the member 14 which overcomes the bias of the spring 16. As best shown in FIG. 3, during the resultant upward or extending movement of the member 14, the lip continues to provide a centering action as well as the aforesaid one way sealing action. The upward movement of member 14 is halted by the engagement of the upwardly facing annular surface 42 thereof with the downwardly facing annular surface 60 of the seal 18 as shown in FIG. 4. The inter-engagement of these two surfaces provides an effective water-tight seal which prevents leakage and insures flow of water outwardly of the housing only through the spray head 34 as is desired.
When the water source is again shut off, the upwardly acting pressure force of the water is reduced so that the downward bias of the spring 16 becomes dominant thereby resulting in a downward movement of the movable member 14 from its extended operative position into its retracted inoperative position. As the member 14 moves from its extended position the surface 42 thereof moves away from seal surface 60 thus breaking the operative seal therebetween. During the downward movement of the member 14, the engagement of the lip 58 with the exterior periphery 40 thereof provides a centering and wiping action thereon as best shown in FIG. 5.
It thus will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing preferred specific embodiment has been shown and described for the purpose of illustrating the functional and structural principles of this invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.