Sprinkler Head Mounting Means

Abstract

Mounting means comprises three major components, an upright sleeve fastened to a conduit member, a nipple rotatable within the sleeve, and a body secured to the top of the nipple and carrying the sprinkler head. The lower end of the nipple has an enlarged shoulder to prevent upward separation from the sleeve and to apply thrust against a set of sealing washers surrounding the nipple and urged against the lower end of the sleeve. A shroud ring surrounds the upper end of the sleeve and the lower end of the body to completely enclose the gap between them and prevent ingress of abrasive particles and other contaminants. The ring is made of imperforate elastic material and is placed in position in axial compression to urge the body and nipple upward with respect to the sleeve and maintain resilient thrust on the washers and keep them in sealing contact at all times.

Description

BACKGROUND OF THE INVENTION

This invention lies in the field of sprinkling devices and has particular utility in connection with agricultural operations. A type of sprinkling device to which the invention may be applied is widely sold under the "Rain Bird" trademark and consists generally of a sleeve which is usually fixedly connected to a conduit member to stand in a generally upright position, a nipple rotatably mounted in the sleeve and provided with a shoulder at its lower end to prevent upward separation of the nipple, and a body which usually constitutes the lower portion of a sprinkler head and is secured to the upper end of the nipple to rotate therewith.

The sprinkler head is provided with a nozzle directed at an upward angle to distribute water over a wide area as the head rotates. An impact or drive arm is mounted on top of the head for rotation about the axis of the nipple and has at one end an impact or drive vane adapted to intermittently move into the path of the stream of water issuing from the nozzle and be diverted thereby. As it swings cyclically, the arm contacts an abutment on the sprinkler head and gradually rotates the head to spread the stream over a large arcuate area.

A seal is provided between the nipple shoulder and the lower end of the sleeve to prevent the supply water from entering between the nipple and sleeve. This is required to prevent general leakage and waste of water but more importantly to keep out grit and dissolved chemicals which would rapidly wear out the long bearing contact between the nipple and the sleeve. There is a radial or axial gap or both between the upper end of the sleeve and the lower end of the body because the latter must rotate freely with respect to the former in order to perform its function.

The presently used construction is generally satisfactory for residential use because of light duty requirements. Generally, only a single such sprinkler is used for a residential lawn, or several widely spaced ones for larger areas, and they are operated only intermittently for short periods. Moreover, they are normally connected to the residential drinking water supply which has a low level of abrasive substances and chemical contaminants. The conventional sealing means is adequate to prevent undue wear for years, and there is very little likelihood of the entry of abrasive materials through the gap at the upper end of the sleeve.

On the other hand, in agricultural operations, it is not uncommon to use sprinklers practically twenty four hours per day for weeks or months as they are moved from one area to another to greatly reduce the number which the farmer must own. The relatively untreated agricultural water which is frequently used contains much more abrasive and chemical material than domestic drinking water, and hence a given amount of leakage will cause much more damage. Once the bearing areas between the nipple and sleeve begin to wear, their axes begin to diverge and prevent good seating of the seals, which results in an acceleration of the rates of leakage and wear.

It is common to use a large number of sprinklers in a given area and to space them close enough so that the precipitation from one sprinkler reaches the next sprinkler or a point close thereto in order to insure that every portion of the ground is adequately watered. The result is that muddy water is constantly being splashed against every sprinkler and thus finds its way into the gap at the top of the sleeve. This water contains a high level of abrasive particles, chemical which were already in the water, and also chemicals which were utilized in the fertilizing process. Hence, the bearing areas between the nipple and sleeve are attacked from the top as well as the bottom and the rate of wear is undesirably high.

SUMMARY OF THE INVENTION

The sealing means of the present invention overcome the difficulties mentioned above and provide a simple assembly which protects the bearing area between the nipple and the sleeve at both ends and has very few parts which are readily installed and are themselves highly resistant to wear or damage. Generally stated, the lower seal group includes a first, resilient, high friction elastomeric backup washer, which may be natural or synthetic rubber, which fits on the shank of the nipple and is in direct contact with its shoulder. A second sacrificial wear washer of plastic material having low friction is assembled on the nipple next to the backup washer and rotates with it. A third slip washer of plastic material having low friction also surrounds the shank of the nipple but is secured to the lower end of the sleeve and remains stationary therewith, so that the rotating seal is between the two plastic washers. The coefficient of friction of the plastic washers is selected to produce the desired resistance to rotation of the sprinkler head.

The upper end of the sleeve is adjacent to the lower end of the body which is secured to the upper end of the nipple. There may be a radial or axial gap or both between the body and the sleeve since the body must rotate freely with the nipple. A shroud ring of imperforate, high friction elastomeric material, such as natural or synthetic rubber, engages the upper end of the sleeve and the lower end of the body to completely enclose the gap between them and prevent ingress of any foreign matter. The shroud ring may be frictionally secured by either one of its ends to either one of these components while its opposite end is provided with a low friction collar which is in rotary sealing engagement with the other component. In some cases a collar may be used at each end.

The shroud ring has a dual purpose. In addition to protecting the gap between the sleeve and the body, it is mounted in axial compression and resiliently urges the body upward with respect to the sleeve. This in turn produces a constant upward thrust force by the nipple shoulder agains the washers to compress them between the shoulder and the lower end of the sleeve. Consequently they are in sealing engagement when the water is turned on, and the initial flow finds no leakage path between them. In the event that there is any angular play between the nipple and the sleeve, it is accommodated by the resilience of the backup washer so that there is no possiblity of even momentary sealing disengagement of the two plastic washers.

BRIEF DESCRIPTION OF THE DRAWING

Various other advantages and features of novelty will become apparent as the description proceeds in conjunction with the accompanying drawing, in which:

FIG. 1 is a perspective view of a typical sprinkling device incorporating the invention;

FIG. 2 is an elevational view, partly in section showing details of the invention;

FIG. 3 is a perspective view of the shroud ring; and

FIG. 4 is a detailed view of the portion 4 of FIG. 3.

DESCRIPTION OF PREFERRED EMBODIMENTS

A typical sprinkling apparatus to which the present invention is adapted to be applied is illustrated in FIG. 1, in which an upright sleeve 10 is mounted to an upright conduit member 12 such as a pipe which may be connected to an underground conduit system or mounted on a movable support and connected to a hose or the like. A hollow body component 14, rotatably mounted on sleeve 10, may be attached to or made integral with sprinkler head 16.

The sprinkler head is formed with an elongate nozzle body 18 extending at a substantial angle to the vertical and provided at its end with a nozzle 20 have a discharge orifice 22. A small diameter stream of water issues from orifice 22 with high velocity to carry a great distance from the nozzle. In order to cover a large arcuate area, which may be a full circle, the sprinkler head rotates about the upright axis of sleeve 10. To cause the rotation, an impact or drive arm 24 is mounted on top of the sprinkler head for rotation about an upright axis and is journaled between the head and bridge 26 which may be integral with the head. Arm 24 is provided at one end with an impact or drive member 28 which moves intermittently into the path of the water stream and is diverted thereby. The water contact and torsion spring 30 cause the arm to swing cyclically, and the arm repeatedly strikes the bridge and causes the sprinkler head to gradually rotate and spread the stream over a large area.

The details of the pivotal mounting and sealing means for the sprinkler head are illustrated in FIG. 2. Sleeve 10, provided with tool engaging formation 32, is tightly secured to conduit member 12 by means of pipe threads 34. Nipple 36 has a cylindrical shank 38 journaled in the cylindrical inner wall 40 of the sleeve and extends beyond both ends of the sleeve. The first, lower, end of the nipple is provided with an enlarged radially extending shoulder 42 which prevents upward separation of the nipple from the sleeve, and the second, upper, end is provided with an attachment formation which may be external thread 44 adapted for fixed engagement with an internal thread 46 in the body. Thus the body and nipple are effectively unitary and rotatable in sleeve 10.

Ingress of supply water to the bearing area between the walls of the sleeve and nipple is prevented by a special group of washers including a backup washer 48, a sacrificial wear washer 50, and a slip washer 52. The backup washer is flexible and resilient and has a relatively high coefficient of friction, and is preferably formed of an elastomer which may be natural or synthetic rubber. It fits on shank 38 and seats against shoulder 42. Because of its high friction value it becomes non-rotatably secured to the nipple. Wear washer 50 may be formed of plastic material and is somewhat flexible but far less so than washer 48 and has a low coefficient of friction, at least on the face which confronts washer 52. It is held non-rotatably by contact with washer 48.

The slip washer 52 is preferably formed of plastic material which is slightly flexible and has a low coefficient of friction. This washer, instead of being flat, has an angular cross section and includes an axial cylindrical wall 54, which is a press fit in counterbore 56 at the lower end of the sleeve, and a radially outwardly extending flange 58 having a planar confronting face for rotary sliding engagement with the wear washer, both of the confronting faces being very smooth. The materials of these two washers are selected to produce a predetermined degree of frictional resistance to rotation of the nipple in the sleeve so that the sprinkler head 16 will remain substantially stationary as the drive arm is rotated against the torsion of the spring but will be slightly rotated in response to impact of the drive arm against the bridge. To accomplish this end it is presently preferred to use ultra high molecular weight polyethylene for the wear washer and polyurethane for the slip washer. A feature of this combination is that the slip washer has a much higher degree of wear resistance than the wear washer. Since a small amount of supply water gradually works its way through the seal there will be some eventual wear, and most of this is taken by the sacrificial wear washer, which is relatively inexpensive and easy to replace.

It will be seen that in the configuration shown in FIG. 2, the upper end 60 of the sleeve is axially spaced from the lower end 62 of the body to define a small axial gap of predetermined size which, among other things prevents dragging contact of the body on the sleeve and resistance to rotation. In the absence of protection, this gap is subject to splashing of muddy water which would work its way into the bearing area between the nipple and the sleeve and cause rapid wear. This is prevented by the provision of the shroud ring 64 which is symmetrical in shape and has a bulging midsection and substantially cylindrical end portions 66 with slightly divergent inner walls, the angle of divergence being about 5.degree.. End 62 of body 14 has a correspondingly tapered outer wall 68 and a radially outwardly extending shoulder 70 spaced axially from the extreme end of the body 14. The shroud ring is formed of flexible imperforate elastomeric material having a relatively high coefficient of friction, and its end portion is so sized that it is a press fit on outer wall 68 with its end face 72 in contact with shoulder 70. With its high coefficient of friction, it thus becomes frictionally secured to the body to rotate therewith. A suitable shroud ring material having very good weather resistance and elasticity is ethylene propylene diene monomer.

The upper end 60 of sleeve 10 is formed with a cylindrical outer wall 74 and with a radially outwardly extending shoulder 76 spaced axially from its extreme end margin. The shroud ring incorporates at its lower end a low-friction collar 78 having a radially outwardly extending flange 82, and an axial wall 80 tapered to match the taper of end portion 66. When the shroud ring is assembled in place, flange 82 of collar 78 contacts shoulder 76 and wall 80 contacts wall 74 to provide a rotatable sliding seal with the sleeve, and block ingress of any muddy water or other contaminant.

The same basic result will be achieved if shroud ring 64 is frictionally secured to the end 60 of sleeve 10, and the collar 78 rotatably and slidably engages wall 68 and shoulder 70 of body 14 since the seal is still complete. However it is presently preferred to use the configuration shown because of the fixed sealing connection between the shroud ring and the body in frictional engagement. In some cases the shroud ring may incorporate a low-friction collar at each end.

Shroud ring 64 performs a dual function because, in addition to preventing ingress of contaminants to the gap between sleeve 10 and body 14, it also insures integrity of the seal at the lower end of nipple 36. The ring is elastic and of sufficient axial length that when it is placed in position between sleeve 10 and body 14 it is under a pre-determined amount of axial compression. It therefore applies resilient axial pressure to shoulder 70 of end portion 62 and shoulder 76 of end portion 60. Since sleeve 10 is stationary, the effect is to resiliently urge body 14 and nipple 36 upwardly, creating a resilient thrust pressure on washers 48, 50, and 52, and maintaining them in sealing engagement at all times. While the water pressure in a flowing system would push nipple 36 upward, its weight would lower it under no-flow conditions and allow the seal to open. The initial surge of water at start-up would then cause some flow through the seal before it closed and cause ingress of some contaminants which would damage both the seals and the bearing area between the nipple and the sleeve. The constant upward urging of the shroud ring precludes this possibility.

The gap between upper end 60 of the sleeve and lower end 62 of the body is large enough axially for adequate manufacturing tolerance but small enough to facilitate other functions, and may be from about 1/16 inch to about 1/8 inch. In any event, it should be less than one half of the compression range of the shroud ring. When the sprinkler is moved about over rough terrain body 14 is repeatedly forced down by inertia relative to sleeve 10. If the gap is large, there will be undue flexure of the shroud ring, causing it to crack and fail prematurely. With the small gap disclosed, ends 60 and 62 contact almost immediately and prevent excessive flexure of the shroud ring. Since end 60 extends above wall 80 of collar 78 as shown, it presents a longer flow path for wear particles to reach the gap. In addition, it defines between itself and the shroud ring a reservoir 84 to retain a substantial quantity of wear particles and prevent them from reaching the gap.

As indicated previously, in the course of time a minute amount of seepage will gradually build up a quantity of water under pressure within the shroud ring 64. This water must eventually escape and, if no path is provided, it will force end portions 66 of the shroud ring completely out of engagement and provide a permanently open path for contaminants to enter. To preclude this possiblity, a generally radial flow path for leakage under pressure is provided.

As best seen in FIGS. 3 and 4, at least one radial groove 86 is provided in at least one end face 72 of the shroud ring. When seepage water pressure builds up within the shroud ring, it will force an end portion 66 radially out of contact with either wall 68 or wall 80 by a minute amount. If no escape is provided, one or both of the end portions will be gradually forced out radially to such an extent that it will slip past the confronting shoulder and be lodged in a position providing an inlet flow path for contaminants. However, when one or more grooves 86 are provided, as soon as an end portion 66 is radially displaced sufficiently for water to seep past it, this water will find a flow path for escape through one of the grooves 86, relieving the pressure and allowing the end portion to return to complete sealing position.

It will be apparent from the disclosure presented herein that the present invention provides a novel and practical solution to the problem of sprinkler leakage which produces excessive wear in the components of a sprinkling apparatus, with a minimum of moving parts and with superior long term durability.

Claims

We claim:

1. Mounting means for a sprinkler head comprising:

a first component in the form of an elongate sleeve having means at a first, lower, end for connection to a supporting conduit member to stand in a generally upright attitude;

a second component in the form of an elongate nipple rotatably mounted in the sleeve and extending beyond the ends of the sleeve;

a third component in the form of a hollow body fixedly secured to the lower portion of a sprinkler head and provided with means for fixed engagement with said nipple to retain the components in assembled relation;

the second, upper, end of the sleeve being spaced from the adjacent portion of the body to define a gap of predetermined extent, and the adjacent ends of the body and sleeve components being axially spaced from each other and having smooth annular outer walls with radially outwardly extending shoulders axially spaced from the extreme end margins, at least one of the shouldered walls diverging from its extreme end margin;

a shroud ring of flexible imperforate material surrounding the upper end of the sleeve and the lower end of the body and in sealing engagement with each to completely enclose the gap between them and prevent ingress of contaminants, the inner walls of the end portion of said ring having angles of divergence corresponding to those of said shouldered walls, said ring having a relatively high coefficient of friction to non-rotatably secure one end to said divergent wall;

and a low friction collar connected to the opposite end of the shroud ring and shaped to conform to the other shouldred wall for rotatable sealing engagement.

2. Mounting means as claimed in claim 1, in which the axial gap formed by the adjacent ends of the body and sleeve is less than one half of the axial compression range of the shroud ring.

3. Mounting means as claimed in claim 1; in which

at least one end of the shroud ring is provided with at least one small radial flow path for the escape of seepage water under pressure from within the shroud ring.

4. Mounting means for a sprinkler head comprising

a first component in the form of an elongate sleeve having means at a first, lower, end for connection to a supporting conduit member to stand in a generally upright attitude;

a second component in the form of an elongate nipple rotatably mounted in the sleeve and extending beyond the ends of the sleeve;

the lower end of the nipple having a radially enlarged shoulder to prevent upward separation of the nipple from the sleeve, and the upper end having an attachment formation;

a third component in the form of a hollow body fixedly secured to the lower portion of a sprinkler head and provided with means for fixed engagement with the attachment formation on the nipple to retain the components in assembled relation;

a plurality of washers surrounding the lower end of the nipple and arranged between the nipple shoulder and the lower end of the sleeve to seal against ingress of contaminants between the nipple and the sleeve and to provide a predetermined degree of frictional resistance to rotation of the nipple in the sleeve;

the second, upper, end of the sleeve being spaced from the adjacent portion of the body to define a gap of predetermined extent, the adjacent ends of the body and sleeve components being axially spaced from each other and having smooth annular outer walls with radially outwardly extending shoulders axially spaced from the extreme end margins, at least one of the shouldered walls diverging from its extreme end margin;

a shroud ring of flexible imperforate material surrounding the upper end of the sleeve and the lower end of the body and in sealing engagement with each to completely enclose the gap between them and prevent ingress of contaminants, the inner walls of the end portions of said ring having angles of divergence corresponding to those of said shouldered walls, said ring having a relatively high coefficient of friction to non-rotatably secure one end to said divergent wall;

and a low friction collar connected to the opposite end of the shroud ring and shaped to conform to the other shouldered wall for rotatable sealing engagement.

5. Mounting means as claimed in claim 4; in which

the collar has an angular cross section with an axial wall externally tapered to match the internal taper of the shroud ring end portion and to be non-rotatably secured therein, and a radially outwardly extending flange to serve as a shoulder and engage the shoulder on its respective component.

6. Mounting means as claimed in claim 4; in which

at least one end face of the shroud ring is provided with at least one small radial groove to provide a flow path for release of leakage water under pressure from within the shroud ring.

7. Mounting means as claimed in claim 4; in which

the shroud ring is bulged outward between its ends to define an annular enclosed space;

and the upper end of the sleeve extends upward a substantial distance above the lower end of the shroud ring to define therewith a reservoir to trap and retain wear particles at a location spaced from the gap between the sleeve and the body.