Abstract:
An adjustable pattern irrigation device is provided with a head member that is pivotably coupled to a plurality of arm members that further serve as a break for incoming water. A cam and follower determine the trajectory of the tilting head member. A plurality of removable and interchangeable cams having an endless number of shapes provided different planned irrigation patterns. Adjustment plates are optionally coupled to the cams to allow for adjustments to the irrigation patterns.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to irrigation devices and more particularly to a sprinkler that is capable of multiple pattern variations to irrigate irregularly-shaped areas. 
     DESCRIPTION OF THE PRIOR ART 
     Residential and commercial irrigation systems are readily available in a variety of configurations for the irrigation of lawns, gardens, landscaping, crops, and the like. Many of these applications provide an area to be irrigated that is irregularly shaped. One of the most common irregular areas that requires irrigation is the ubiquitous rectangular-shaped residential lawn. The corners and straight perimeters of residential lawns provide a challenge to those people who use rotating sprinkler heads, especially those that are positioned on a mobile base and must be strategically repositioned throughout the yard in an attempt to obtain full coverage with the circular spray pattern. 
     Typical impact or rotary head sprinklers provide a circular spray pattern as the head of the sprinkler travels in its 360° path. The formation of circular spray patterns causes the individual to frequently move the sprinkler to deliver water to each of the outlaying perimeter and corner areas. Typically, the only alternative is to simply position the sprinkler unit adjacent the corner area and deliver a sufficient volume of water through the sprinkler unit to reach the farthest point of the corner. However, this method typically delivers a large volume of water beyond the perimeter of the corner, or worse, only serves to water the fence or adjacent properties. 
     The need to conserve water and the desire to simplify the process of irrigating irregular plots of land has led to the development of several different improvements to the typical rotary or impact type of sprinkler unit. U.S. Pat. No. 3,528,093 discloses an impact sprinkler head that uses a cam and follower to regulate the volume of water being discharged from the sprinkler head as it rotates along its circular path. By varying the water flow, the system is purportedly capable of forming “generally square patterns.” U.S. Pat. No. 3,081,039 discloses an impact sprinkler device that uses a cam and follower system to change the trajectory of the water being discharged from the sprinkler unit. In this system, the sprinkler head is positioned directly on top of the water column that is forced into the unit and up through the sprinkler stem. This arrangement frequently causes a problem in that the force of the water traveling through the system and up the stem directly impacts the pivoting joint that couples the sprinkler head to the stem. The force of the water makes it difficult, if not impossible, to smoothly and accurately pivot the sprinkler head. To that end, the &#39;039 patent teaches the necessity of an adjustable weight member that is coupled to an arm extending from the lower end of the follower in order to force the movement of the sprinkler head into and out of its desired angle of discharge. 
     Other prior art systems have attempted to combine the two methodologies of variable water flow and discharge trajectory in order to create a more efficient and accurate system. One example of such a device is disclosed within U.S. Pat. No. 5,248,093. However, most systems taking this approach are overly complex, rendering them expensive to manufacture and susceptible to multiple and frequent mechanical error. The adjustments and upkeep of such a system, combined with its cost, render it impractical for most applications. 
     Accordingly, what is needed is an irrigation device that is simple in construction and operation, yet accurate in its formation of variable discharge patterns. 
     SUMMARY OF THE INVENTION 
     The sprinkler device of the present invention is provided with a head member having a fluid inlet and a discharge nozzle. A support member is pivotably coupled to the fluid inlet portion of the head member to permit the selective alteration of the angle at which the discharge nozzle of the head member is oriented. The support member is rotatably coupled with a stem member to permit the head and support members to rotate in a circular manner. The support member is provided with a plurality of arm members that separate and divert the column of water after it enters the support member. The arm members then rejoin the separate water columns at the base of the head member. In this manner, the arm members provide a water brake to limit the “impact” effect of the water column as well as a pivoting joint to allow for the smooth and effortless change in discharge trajectory. 
     An elongated follower extends outwardly from the head member to engage the peripheral edge of a cam, which is coupled to the stem member. As the sprinkler rotates, the follower is directed along the shape of the cam to systematically raise and lower the pitch of the head member. The shape of the cam member determines the irrigation pattern of the system. Accordingly, it is preferred that the cam be removably coupled to the stem member so that additional cam members of different shapes can be interchanged as needed. 
     The sprinkler can also be fit with an adjustable cam, having an adjusting plate that is slidably engaged with the upper or lower surface of the cam. The adjusting plate selectively changes the shape of the cam and, thus, the irrigation pattern of the sprinkler device. A plurality of adjustment plates can be provided to simultaneously adjust the shape of the cam in more than a single direction. 
     Accordingly, it is a principal object of the present invention to provide an improved irrigation device that is capable of variable irrigation patterns. 
     A further object of the present invention is to provide an improved irrigation device that is capable of variable irrigation patterns but simple in construction and operation. 
     Yet another object of the present invention is to provide an improved variable pattern irrigation device that is capable of simple irrigation pattern shape adjustments. 
     Still another object of the present invention is to provide an improved variable pattern irrigation device having a plurality of interchangeable pattern cams for the selective variation of the irrigation pattern. 
     Yet another object of the present invention is to provide a system for varying irrigation patterns that can be used with many different types of irrigation systems. 
     These and other objects will be apparent to those skilled in the art. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation view of a prior art irrigation device; 
     FIG. 2 is a perspective view of an embodiment of the variable pattern irrigation system of the present invention in a generally high trajectory position; 
     FIG. 3 is a perspective view of the variable pattern irrigation system of FIG. 2 in a generally low trajectory position; 
     FIG. 4A is a top view of one embodiment of a cam which can be used as a part of the variable pattern irrigation system of the present invention; 
     FIG. 4B is a top view of another embodiment of the cam of FIG. 4A; 
     FIG. 4C is a top view of another embodiment of the cam of FIG. 4A; 
     FIG. 4D is a top view of yet another embodiment of the cam of FIG. 4A; 
     FIG. 5 is a perspective view of an embodiment of the adjustable cam of the present invention; 
     FIG. 6 is a partial exploded view of the support member of the variable pattern irrigation device of FIG. 2; and 
     FIG. 7 is a perspective view of an alternate embodiment of the variable pattern irrigation system of FIG.  2 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The irrigation device  10  of the present invention is generally depicted in FIGS. 2-6. The irrigation device  10  is provided with a head member  12  having a fluid inlet portion  14  and a fluid discharge portion  16 . Generally, the discharge end portion  16  will be fitted with one of many known styles of spray nozzles. The sprinkler head  12  is depicted in the figures as being an impact sprinkler head having an impact arm  18  that is rotatably coupled with the head member  12  and is biased toward the path of the discharging fluid by a spring  20 . However, it will be apparent to those of skill in the art that the improvements disclosed herein are equally applicable to rotary sprinkler systems and other sprinkler devices using various rotation systems. 
     The head member  12  of the irrigation device  10  is pivotably supported by a support member  22 , having a fluid inlet portion  28  and an fluid outlet portion  29 . In a preferred embodiment, the support member  22  is provided with at least two arm members  24  and  26 , which pivotably engage the fluid inlet portion  14  of head member  12  to form a pivotable joint. The arm members  24  and  26  divide the water column that is received by the fluid inlet end portion  28 . As the separate water columns exit the outlet end portion  30  of the support member  22 , they are rejoined within the inlet portion  14  of the head member  12 . Although the arm members  24  and  26  are generally depicted as being C-shaped, it is contemplated that the arm members  24  and  26  could be formed in a nearly limitless number of configurations. It is further contemplated that more than two arm members could be provided. However, it is important that the arm members provide at least one axis on which the head member  12  can pivot back and forth to vary the trajectory of the discharge end portion  16 . 
     It is preferred that the arm members  24  and  26  be configured so that a water brake is formed. The water brake checks the force of the water column before it reaches the head member  12 . This prevents the formation of an “impact zone,” which would potentially limit or alter the desired pivoting motion of the head member  12 . Such impact effects readily occur within typical prior art assemblies. The prior art assembly shown within FIG. 1 includes a sprinkler body that rotates within a journal bearing  1 , which secures the sprinkler to either an underground water supply or to a mobile base frame. The water supply enters the sprinkler at its inlet portion  2  and travels coaxially with the sprinkler body and typically impacts a joint member  3  that is provided for pivoting the sprinkler head in an upward and downward manner. This typically has the effect of either pinning the joint  3  in position or forcing the head  4  in the direction of the water column&#39;s path. Accordingly, it is desired to provide a water break, such as that provided by arm members  24  and  26 , to prevent either of these phenomena from occurring and adversely affecting the operation of the head member. 
     The support member  22  is rotatably coupled to a journal member  32 , which is located at the output end portion  34  of the stem  30 . The journal member  32  permits the rotation of the head member  12  and support member  22  along its 360° path. The inlet end portion  36  of the stem  30  is engageable with nearly any contemplated fluid source, from an underground water line to a simple base frame that is selectively and movably positioned throughout the area to be watered. 
     The sprinkler  10  of the present invention creates a specific irrigation pattern by varying the trajectory on which the water is distributed from the head member  12  as it rotates about the stem  30 . The trajectory is preferably dictated using a follower  38  and cam  40 . The follower  38  is preferably an elongated member having one end coupled with either the head member  12  or the support member  22 . The opposite end of the follower  38  slidably engages the peripheral edge portion  42  of the cam  40 . The peripheral edge portion  42  is formed to provide the cam  40  with a particular shape. Examples of these particular shapes are depicted in FIGS. 4A-4D. 
     The shape of the cam  40  dictates the shape of the resulting irrigation pattern. For example, the cam  40  depicted in FIG. 4A is generally rectangular in shape. It has opposite short side portions  44  and  46  and longer side portions  48  and  50 . An opening  52  is formed in the center of the cam  40  and is preferably sized to receive the diameter of the stem  30 . To facilitate the ease in mounting and removing the cam  40  to and from the stem  30 , the cam may be split along one axis, such as between long side portions  48  and  50 , and a pivot pin  53  or similar member may be coupled to the cam  40  closely adjacent the peripheral edge  42 . This permits the opening of the cam  40  so that the stem  30  may be received within the opening  52 . It is contemplated, however, that, where a flexible and resilient material is used to form the cam  40 , a pivot pin may not be necessary. 
     In operation, as the follower  38  is slidably engaged with the short end portion  46 , the head member  12  will be tilted rearwardly in a high trajectory position, as depicted in FIG.  2 . As the sprinkler device  10  continues along its rotational path, the follower  38  slides along the peripheral edge portion  42  until it moves from the short side portion  46  to the long side portion  48 . Due to the closer proximity of the longer side portion  48  to the opening  52 , the follower  38  will move toward the stem  30 , thus dropping the head member  12  forward into its low trajectory elevation, as depicted in FIG.  3 . The low trajectory elevation directs the water more directly at the ground surface and thus travels a shorter distance than it did when the head portion  12  was in its high trajectory elevation. Accordingly, as the sprinkler device  10  completes a full 360° rotation, a rectangular irrigation pattern resembling the shape of the cam  40  will be produced. 
     For more irregular irrigation patterns, the cam  40  can be provided in nearly any required shape, as shown in FIGS. 4B and 4D. Again, the irrigation pattern created by the sprinkler device  10  will mimic the shape of the outer edge portion of the cam  40 . Accordingly, where it is desired to have the typical round irrigation pattern, a round cam  40  could be provided, such as that depicted in FIG.  4 C. It is contemplated that more than one cam  40  could be coupled with one another to provide an additional irrigation pattern variation without having to form a separate cam  40 . For example, the round cam  40  of FIG. 4C could be positioned adjacent the upper or lower surface of the cam  40  depicted in FIG. 4A when they are positioned on the stem  30 . In this configuration, the portion of the irrigation pattern mimicking the longer side portions  48  and  50  would become rounded and cover a larger area away from the sprinkler device  10  than if the cam  40  of FIG. 4A were used alone. 
     The irrigation pattern created by the sprinkler device  10  can be further altered where an adjustable cam  54  is provided, such as that depicted in FIG.  5 . Cam  54  is similar to the cams  40 , depicted in FIGS. 4A-4D. However, an extension plate  56  is slidably coupled with the upper or lower surface of the cam  54  and secured with a set screw  58  or similar structure. Accordingly, when it is desired to increase the size of the irrigation pattern created by the sprinkler device  10 , the set screw  58  can be disengaged, and the adjustment plate  56  can be slid outwardly from the cam  54  by a desired distance. The set screw  58  would again be secured, and the system can be operated accordingly. It is contemplated that a plurality of adjustment plates  56  could be coupled to the cam  54  to provide for adjustments in more than one direction and in more than one axis. 
     The trajectory joint of the present system, as mentioned previously, is provided by the coupling of the arm members  24  and  26  with the fluid inlet portion  14  of the head member  12 . As depicted in FIG. 6, where the support member  22  is provided with two arm members, the fluid inlet portion  14  of the head member  12  will be provided with a pair of mating members  60  and  62  that are comprised at least of flanges  64  and  66  and a pair of collar members  68  and  70 . It is preferred that the collar members  68  and  70  are provided with mating threads to receive the threaded ends  72  and  74  of the arm members  24  and  26 . Accordingly, when the mating collars  68  and  70  are coupled to arm members  24  and  26 , the flange members  64  and  66  engage the open end portions of the arm members  24  and  26  to permit the flow of the fluid into the fluid inlet portion of the head member  12 . Seals  76  and  78 , such as the resilient O-rings depicted in FIG. 6, can be provided for additional protection against the leaking of fluid from the pivoting joint. Similarly, additional seals of different materials and shapes can be provided where leaks are discovered between the flange members  64  and  66  and the open end portions of the arm members  24  and  26 . 
     It is contemplated that, due to external forces and various operating conditions, that the force of the water being expelled from the outlet end portion  16  of the head member  12  could force the head member  12  to pivot rearwardly and disengage the follower  38  from the edge portion  42  of the cam  40 . Accordingly, a retaining arm  80  can be provided to ensure continuous engagement between the follower  38  and the cam  40 . The retaining arm  80 , depicted in FIG. 6, is preferably provided with a pivot end portion  82  that is pivotably engaged with the support member  22  or the stem member  30 . It is contemplated, however, that the pivot end portion  82  could be secured in a fixed position to the support member  22 . An elongated arm  84  extends outwardly from the pivot end portion  82  and is slidably received within an arm housing  86 . The arm  84  and arm housing  86  are preferably engaged to one another with a spring  88  within the arm housing  86 . Accordingly, the length of the retaining arm  80  can fluctuate while remaining biased toward the pivot end  82 . A collar portion  90  is preferably disposed on the free end of the arm housing  86  and slidably engages the length of the follower  38 . It is preferred that the opening  92  within the collar portion  90  be sized to be only slightly larger than the diameter of the follower  38 . 
     In use, the retaining arm  80  forces the follower  38  into engagement with the peripheral edge portion  42  of the cam  40  and resists the force of the water exiting the system from tipping the head member  12  rearwardly. As the shape of the cam  40  changes and the head member  12  pivots forwardly and rearwardly, the arm  84  and arm housing  86  move with respect to one another to accommodate the movement of the follower  38 . 
     In an alternate embodiment depicted in FIG. 7, the force of the exiting water is used to keep the follower  38  in constant contact with the peripheral edge portion  42  of the cam  40 . This is accomplished by lengthening the arm members  24  and  26  and raising the location at which the mating members  60  and  62  engage the head member  12 . It is preferred that the mating members  60  and  62  engage the head member  12  at a position slightly above the location at which the output end portion engages the head member  12 . In this arrangement, the thrust provided by the exiting stream of water will tend to force the head to pivot in a generally downward direction and maintain the engagement between the follower  38  and the peripheral edge portion  42  of the cam  40 . 
     In the drawings and in the specification, there have been set forth preferred embodiments of the invention; and although specific items are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and proportion of parts, as well as substitution of equivalents, are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims. 
     Thus it can be seen that the invention accomplishes at least all of its stated objectives.