US20060185069A1

US20060185069A1 - Pulsating waterjet valve

Info

Publication number: US20060185069A1
Application number: US11/064,867
Authority: US
Inventors: Russ Wooten
Original assignee: Individual
Current assignee: Custom Molded Products LLC
Priority date: 2005-02-24
Filing date: 2005-02-24
Publication date: 2006-08-24

Abstract

A device for producing a pulsating waterjet having a manifold body with a hollow interior, a fluid inlet, and at least one outlet leading from the hollow interior and fluidly connecting the hollow interior to at least one waterjet; and a selector cam having at least one propelling vane and at least one dam that cooperates with the at least one outlet so as to sequentially align with and unalign with the at least one outlet, wherein the selector cam is rotationally mounted within the hollow interior of the manifold body, whereby fluid entering the manifold body through the fluid inlet impinges upon the at least one propelling vane imparting rotational motion to the selector cam and the at least one dam thereby rotating the at least one dam such that when the at least one dam aligns with the at least one outlet fluid is allowed to exit the manifold body through the at least one outlet and when the at least one dam unaligns with the at least one outlet fluid is thwarted from exiting the manifold body through the at least one outlet.

Description

BACKGROUND OF THE INVENTION

1. Technical Field
The present invention generally is in the field of devices for generating pulsating jets of water, and more particularly is in the field of valves for generating pulsating jets of water through one or more waterjets in spas, swimming pools, tubs and the like.
2. Prior Art
Waterjets can be used in artificial water structures, such as pools, spas and hot tubs (for ease of this disclosures, all artificial water structures will be referred to as spas in this disclosure), to provide jets of water to provide a massaging and therapeutic action. The massaging and therapeutic action usually is provided by waterjets that are recessed into the walls of the artificial water structures. Several waterjets are usually spaced about the perimeter of an artificial water structure. Waterjets typically comprise nozzles for forming and adjusting the water flow through the waterjets and, in some waterjets, the nozzles may be rotated to achieve a desired flow. The nozzle is often a swivel type nozzle, which allows the direction of the flow to be adjusted by the user of the artificial water structure for maximum massaging or therapeutic action.
Spas often are provided with a number of waterjets around its periphery for the introduction of water or aerated water into the main body of water in the spa. The water can be supplied in steady stream or in a pulsating manner. Generally, water is supplied by way of a manifold valve to all of the waterjets in a spa continuous manner. The waterjets themselves often are adjustable to allow the water to flow therethrough in a steady stream or in a pulsating manner. However, such prior art waterjets require a separate pulsator unit for each nozzle, increasing the complexity, cost and maintenance of the spa.
Accordingly, there is a need for a central device that allows for the pulsation of some or all of the waterjets in an artificial body of water, such as a spa, swimming pool, tub or the like with a minimum of manufacturing and installation costs. There also is a need for a central device that allows for the concurrent pulsation of waterjets in a spa or the pulsation of the waterjets in a spa in a set sequence or rotation. It is to these needs and others that the present invention is directed.

BRIEF SUMMARY OF THE INVENTION

Briefly described, the present invention is a valve for sequentially diverting the water being supplied to the waterjets in a spa in such a manner that the various waterjets emit water into the spa in a pulsating manner. In its most basic configuration, the valve comprises a multi-port manifold body and a water-driven selector cam rotationally contained within the manifold body.
The valve can be included in a more or less typical spa water circulation scheme comprising a spa, the valve, one or more waterjets, and connecting fluid carrying conduits. Water is pumped through the valve such that the water impinges generally normal to the plane of a propelling vane in the valve. Water flowing into the valve through a water inlet end impinges on the propelling vane causing the propelling vane to rotate. This rotation causes cam lobes, which are attached to a spindle to which the propelling vane also is attached, to rotate and for dams located at the outward ends of the cam lobes to align and unalign with outlets (ports) in the manifold body. The outlets are fluidly connected to the waterjets. The alternating alignment and unalignment of the dams with the outlets causes the water flowing through the valve to be distributed to the waterjets in an intermittent manner to create a pulsating effect.
In operation, water that is pumped through the valve is supplied in a pulsating manner to those waterjets connected to the valve. The water can be supplied to the waterjets in a sequence dependant on the positioning of the cam lobes about the spindle. For example, the waterjets can be fluidly connected to the outlets in a pattern allowing the pulsating effect to appear to rotate around the spa, in a pattern allowing alternate (every other) waterjets to pulse, or in many other patterns. Thus, water can be distributed to one or more of the waterjets at any one time in accordance with the invention. Preferably, water is distributed to fewer than all of the waterjets at any one time.
These features, and other features and advantages of the present invention will become more apparent to those of ordinary skill in the relevant art when the following detailed description of the preferred embodiments is read in conjunction with the appended drawings in which like reference numerals represent like components throughout the several views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of the invention.
FIG. 2 is a side view of the manifold body of the present invention.
FIG. 3 is a sectional side view of the manifold body of FIG. 2.
FIG. 4 is an end view of the manifold body of FIG. 2.
FIG. 5 is an exploded perspective view of the selector cam of the present invention.
FIG. 6 is a side view of the selector cam of the present invention.
FIG. 7 is an end view of the selector cam of FIG. 6 from the water inlet end showing the propelling vanes.
FIG. 8 is an end view of the selector cam of FIG. 6 from the end opposite the water inlet end showing the cam lobes.
FIG. 9 are schematic sectional views of the present invention in four positions showing the flow of the water through the invention, with FIG. 9A being in a first position, FIG. 9B being in a position rotated 90 degrees from the first position, FIG. 9C being in a position rotated 180 degrees from the first position, and FIG. 9D being in a position rotated 270 degrees from the first position.
FIG. 10 is a schematic of an array of waterjets in a spa connected to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Illustrative embodiments of a pulsating waterjet valve 10 according to the present invention are shown in FIGS. 1 through 10. FIG. 1 is an exploded perspective view of the invention showing how the manifold body 12 and the selector cam 30 fit together. FIG. 2 is a side view of the manifold body 12 of the present invention illustratively configured with a single inlet 14 and eight outlets 16 for controlling up to eight waterjets 90 (see FIG. 8). FIG. 3 is a sectional side view of the manifold body of FIG. 2 illustrating the hollow interior manifold 18. FIG. 4 is an end view of the manifold body of FIG. 3 viewing from the water inlet end 20.
FIG. 5 is an exploded perspective view of the selector cam 30 of the present invention showing how the propelling vanes 36, the cam lobes 32, and the spindle 34 fit together. FIG. 6 is a side view of the selector cam 30 of the present invention illustratively configured to cooperate with the manifold body 12 by having eight cam lobes 32 attached to a central axial spindle 34. FIG. 7 is an end view of the selector cam 30 of FIG. 6 from the water inlet end 20 showing the propelling vanes 36 for rotating the selector cam 30. FIG. 8 is an end view of the selector cam 30 of FIG. 6 from the end opposite the water inlet end 20 showing the cam lobes 32.
FIG. 9 are schematic sectional views of the present invention in four positions showing the flow of the water through the invention. FIG. 9A illustrates the selector cam 30 in a first position allowing water to flow through a limited number of outlets 16 to a limited number of corresponding waterjets 90. FIG. 9B illustrates the selector cam 30 in a second position rotated 90 degrees from the first position allowing water to flow through a limited number of outlets 16 to a limited number of corresponding waterjets 90, which are not necessarily the same outlets 16 and waterjets 90 as in the first position. FIG. 9C illustrates the selector cam 30 in a third position rotated 90 degrees from the second position allowing water to flow through a limited number of outlets 16 to a limited number of corresponding waterjets 90, which are not necessarily the same outlets 16 and waterjets 90 as in the first or second positions. FIG. 9D illustrates the selector cam 30 in a fourth position rotated 90 degrees from the third position allowing water to flow through a limited number of outlets 16 to a limited number of corresponding waterjets 90, which are not necessarily the same outlets 16 and waterjets 90 as in the first, second or third positions. FIG. 10 is a schematic of an array of waterjets 90 in a spa 80 connected to the present invention.
Referring to FIGS. 1 through 4, manifold body 12 is shown. Manifold body 12 is a generally cylindrical structure having an outer sidewall 22 and an end cap 24 forming a hollow interior manifold 18. Open water inlet end 20, which is located at the opposite end of manifold body 12 from end cap 24, connects to water inlet conduit 84 (see FIG. 10) for supplying water to the device 10. One or more outlets 16 are formed into and arranged radially along outer sidewall 22, preferably in two rows parallel to and opposite each other from a central axis 26 through manifold body 12. Outlets 16 are hollow tubes and each has an inner end that opens radially into hollow interior manifold 18 and an outer end that opens external of manifold body 12.
Although outlets 16 are shown in two longitudinal respective rows opposite each other about central axis 26, the rows of outlets 16 can be rotationally spaced from each other about central axis 26 by any desired increment, such as two rows rotationally spaced 180 degrees from each other, three rows rotationally spaced 120 degrees from each other, four rows rotationally spaced 90 degrees from each other, etcetera. Further, there need only be one row of outlets 16. It is within the scope of this invention to provide outlets 16 or rows of outlets 16 that are longitudinally and/or rotationally spaced relative to the central axis 26 in any number and combination.
Manifold body 12 can be a single structure comprising outer sidewall 22, end cap 24 and outlets 16, or it can be a combination of separate structures. For example, in the preferred embodiment, outlets 16 and outer side wall 22 is a single structure and end cap 24 is a separate structure. In this preferred embodiment, end cap 24 is attached to outer side wall 22 using screw threads 28 such that end cap 24 is removable from outer side wall 22, thus allowing access to hollow interior manifold 18. As discussed later, this allows the insertion and removal of selector cam 30 into and out of hollow interior manifold 18 for cleaning, repair, and replacement, and for the use of alternative selector cams 30.
Primary selector cam support 50 is located proximal to water inlet end 20 of manifold body 12. Primary support 50 is a structure extending across the diameter of interior of manifold body 12, that is, across hollow interior manifold 18, normal to central axis 26. Centrally located on primary support 50, coaxial with central axis 26, is a first bearing or receiving slot 52 into which the first end 62 of spindle is received for mounting selector cam 30 within manifold body 12. Similarly, end cap 24, whether a separate structure or a part of manifold body 12, comprises an inner surface 60 comprising a second bearing or receiving slot 54 into which the second end 64 of spindle 34 is received for mounting selector cam 30 within manifold body 12. In this manner, end cap 24 acts as a secondary selector cam support. Together, end cap 24 and primary selector cam support 50 rotationally support selector cam 30 within manifold body 12 such that selector cam 30 can rotate within hollow interior manifold 18.
Referring to FIGS. 5 through 8, selector cam 30 is shown. Selector cam 30 comprises cam lobes 32 and a propelling vane 36 mounted on a spindle 34. Spindle 34 is a generally cylindrical rod, preferably of a constant diameter, terminating at a first water inlet end 40 with journal 38 and a second end 42 with journal 44. Journals 38, 44 preferably are of a smaller diameter than spindle 34. Propelling vane 36 is located at or proximal to first water inlet end 40 of spindle 34. Cam lobes 32 are securely located along spindle 34 between propelling vane 36 and second end 42 of spindle 34.
Propelling vane 36 is a more or less typical propeller-shaped structure that is securely attached to or a part of selector cam 30. If formed as a part of selector cam 30, propelling vane 36 is formed at water inlet end 40 such that when water enters valve 10 from a water source, the water can contact propelling vane 36 without first having been impeded or otherwise acted on by, for example, cam lobes 32. If formed as a separate structure, propelling vane 36 can have a central axial mounting hole that has an inner diameter that either fits snugly and coaxially over journal 38 or over spindle 34. In either formation, propelling vane 36 is securely attached to selector cam 30 such that when water contacts propelling vane 36 and causes propelling vane to rotate, this rotation also is imparted to the entire selector cam 30 causing selector cam 30 to rotate.
Cam lobes 32 comprise arc-shaped dam 46 and one or more support 48, which are shown as struts in the exemplary embodiment shown in the FIGs. The outer arc curvature surface of dam 46 is generally equivalent to and cooperates with the inner curvature surface of manifold body 12. Support 48 supports dam 46 relative to spindle 34 at a set distance from spindle 34. More specifically, the distance between outer surface of dam 46 and central axis 26 (which is central to both manifold body 12 and cam selector 30) is slightly less than the inner diameter of manifold body 30, that is, slightly less than the diameter of hollow manifold interior 18. As a result, selector cam 30 can be inserted into manifold body 12 within hollow manifold interior 18 with dam 46 proximal to but not necessarily touching the inner surface of manifold body 12. In this manner, selector cam 30 can rotate within manifold body 12 with cam lobes very close to the inner surface of manifold body 12 but without cam lobes 32 preventing selector cam 30 from rotating within manifold body 12.
Cam lobes 32 are arranged on spindle 34 such that dams 46 cooperate with outlets 16. More specifically, as selector cam 30 rotates within manifold body 12, dams 46 alternately align with and unalign with their respective outlets 16. Thus, when dam 48 aligns with a specific outlet 16, water is prevented from flowing through that specific outlet 16 to the waterjet 90 associated with that specific outlet 16, and when dam 48 unaligns with that specific outlet 16, water is allowed to flow though that specific outlet 16 to the waterjet 90 associated with that specific outlet, creating the pulse of water. In various embodiments of the valve 10, each dam 46 may cooperate with one or more outlets 16 and one or more dams 46 may cooperate with each outlet 16. Further, cam lobes 32 can be arranged on spindle 34 in any manner of configurations. For example, cam lobes 32 can line up with each other such that all waterjets 90 pulse at the same time, cam lobes 32 can be entirely offset from each other such that only one waterjet 90 pulses at a time, and cam lobes 32 can be offset in various arrangements so as to set up a specific pattern of pulses through waterjets 90.
Dam 48 has an arc length (partial circumference) of less than the circumference of the inner surface of manifold body 12, and preferably up to about one-half the circumference of the inner surface of manifold body 12, and more preferably approximately one-quarter the circumference of the inner surface of manifold body 12. The arc length can be chosen to provide the desired water pulse duration. Dam 48 has a height (length along central axis) of at least the diameter of outlet 16 and preferably slightly greater than the diameter of outlet 16. It is not necessary that dam 46 prevent all water flow into outlet 16 when dam 46 aligns with outlet 16; however, it is preferable that water flow into outlet 16 is sufficiently reduced to create a pulsating effect through waterjet 90 caused by the alignment and unalignment of dam 46 with outlet 16.
Supports 48 preferably are relatively thin strut-like structures so as to reduce interference with water flowing through valve 10 and to minimize or reduce backflow of water within valve 10. Alternatively, supports 48 can be panels extending radially from and parallel to central axis 26, which would provide additional strength with minimal additional water flow impedance. Alternatively, supports 48 can be vanes extending radially from and generally parallel to central axis 26 but having an offset such that they would assist propelling vane 36 in rotating selector cam 30.
Referring to FIG. 9, selector cam 30 (see FIGS. 5 through 8) is rotationally mounted within and coaxial with manifold body 12. Either end cap 24 or primary support 50, or both, can be removable to allow the insertion and removal of selector cam 30 into and out of manifold body 12. In the preferred embodiment, primary support 50 is securely attached to manifold body 12 and end cap 24 can be removed from manifold body 12 to allow access to hollow manifold interior 18. More specifically, with end cap 24 removed from manifold body 12, selector cam 30 can be inserted into or removed from hollow manifold interior 18. Journal 38 is inserted into receiving slot 52 on primary support 50. End cap 24 then is replaced onto manifold body 12 such that journal 44 is inserted into receiving slot 54 on end cap 24. In this manner, selector cam 30 is rotationally supported within hollow manifold interior 18 of manifold body 12 such that selector cam 30 is coaxial with manifold body 12 along central axis 26. End cap can be attached by screw threads 28, adhesive, sonic welding, friction, clips, or any other attachment means.
As selector cam 30 preferably is removable, should selector cam 30 break it can be replaced. Further, different selector cams 30 having different configurations of cam lobes 32 can made so as to produce different pulsation patterns through waterjets 90. For example, by changing the rotational offset of one set of cam lobes 32 relative to another set of cam lobes 32 or relative to each other within a set (two opposed cam lobes 32 per set are shown in the illustrative FIGs.), or by changing the number of cam lobes 32 per set or the arc length of a cam lobe 32, different pulsation patterns can be created. Thus, the user can replace one selector cam 30 with another selector cam 30 should selector cam 30 break or should the user desire a different pulsation pattern.
Although an eight-outlet 16, eight-dam 46 configuration is shown, this is for illustrative purpose only, as manifold body 12 can have any number of outlets 16 and selector cam 30 can have any number of dams 46, so long as there is at least one outlet 16 and one associated dam 46. As water enters valve 10 through water inlet end 20, the water impinges on and imparts a force to propelling vane 36, which causes propelling vane 36 to rotate. As propelling vane 36 rotates, thus rotating cam lobes 32, dams 46 align and unalign with outlets 16. When dams 46 align with outlets 16, water is for the most part prevented from flowing through outlets 16 to waterjets 90, and when dams 46 unalign with outlets 16, water is allowed to flow through outlets 16 to waterjets 90.
FIG. 9A illustrates the selector cam 30 in a first position allowing water to flow through a limited number of outlets 16 to a limited number of corresponding waterjets 90. FIG. 9B illustrates the selector cam 30 in a second position rotated 90 degrees from the first position allowing water to flow through a limited number of outlets 16 to a limited number of corresponding waterjets 90, which are not necessarily the same outlets 16 and waterjets 90 as in the first position. FIG. 9C illustrates the selector cam 30 in a third position rotated 90 degrees from the second position allowing water to flow through a limited number of outlets 16 to a limited number of corresponding waterjets 90, which are not necessarily the same outlets 16 and waterjets 90 as in the first or second positions. FIG. 9D illustrates the selector cam 30 in a fourth position rotated 90 degrees from the third position allowing water to flow through a limited number of outlets 16 to a limited number of corresponding waterjets 90, which are not necessarily the same outlets 16 and waterjets 90 as in the first, second or third positions.
FIG. 10 is a schematic of an array of waterjets 90 in a spa 80 connected to the present invention. To illustrate the various embodiments of the use of the invention, FIG. 10 is a collage of the various embodiments and is not meant to be the sole configuration. Specifically, valve 10 is shown with eight outlets 16 such that valve 10 can pulse up to eight waterjets 90. However, two of outlets 16 are capped with caps 72, illustrating that it is not necessary for all of outlets 16 to be connected to waterjets 90. Further, spa 80 is shown with eight waterjets 90 such that at least two waterjets 90 are not pulsed by valve 10, illustrating that spa 80 can have waterjets 90 not attached to valve 10.
FIG. 10 illustrates that valve 10 can be included in a more or less typical spa water circulation scheme comprising spa 80, valve 10, waterjets 90 and connecting conduits 96. Water is pumped through valve 10, or directly to waterjets 90. Water preferably is supplied to valve 10 generally parallel to central axis 26, that is longitudinal to spindle 34 and hollow interior manifold 18, such that the water impinges generally normal to the plane of propelling vane 36. Water that is pumped through valve 10 is supplied in a pulsating manner to those waterjets 90 connected to valve 10. The water can be supplied to waterjets 90 in a sequence dependant on the positioning of cam lobes 32 about spindle 34. Waterjets 90 can be fluidly connected to outlets 16 in various sequences resulting in various pulsating patterns in spa 80. For example, waterjets 90 can be fluidly connected to outlets 16 in a pattern allowing the pulsating effect to appear to rotate around spa 80, in a pattern allowing alternate (every other) waterjets 90 to pulse, or in many other patterns. Thus, water can be distributed to one or more waterjets 90 at any one time in accordance with the invention. Preferably, water is distributed to fewer than all of waterjets 90 at any one time; however, an alternate selector cam 30 can be inserted that allows water to be distributed to all waterjets 90 at the same time, effectively eliminating the pulsating feature of the invention.
In operation, water flowing (arrow W) into valve 10 through water inlet end 20 impinges on propelling vane 36 causing propelling vane 36 to rotate. This rotation causes cam lobes 32 to rotate and for dams 46 to align and unalign with outlets 16. The alternating alignment and unalignment of dams 46 with outlets 16 causes the water to be distributed to waterjets 90 in an intermittent manner to create a pulsating effect. Waterjets 90 introduce water into spa 80. Water then is recirculated. Although only one propelling vane 36 is shown, more than one propelling vane 36 can be used. For example, a second propelling vane 36 can be located at second end 42 to possibly balance the first propelling vane 36. Alternatively, propelling vanes 36 can be located between each set of cam lobes 32.
The foregoing detailed description of the preferred embodiments and the appended figures have been presented only for illustrative and descriptive purposes and are not intended to be exhaustive or to limit the scope and spirit of the invention. The embodiments were selected and described to best explain the principles of the invention and its practical applications. One of ordinary skill in the art will recognize that many variations can be made to the invention disclosed in this specification without departing from the scope and spirit of the invention.

Claims

1. A device for producing a pulsating waterjet comprising:

a manifold body having a hollow interior, a fluid inlet, and at least one outlet leading from the hollow interior and fluidly connecting the hollow interior to at least one waterjet; and

a selector cam having at least one propelling vane and at least one dam that cooperates with the at least one outlet so as to sequentially align with and unalign with the at least one outlet,

wherein the selector cam is rotationally mounted within the hollow interior of the manifold body,

whereby fluid entering the manifold body through the fluid inlet impinges upon the at least one propelling vane imparting rotational motion to the selector cam and the at least one dam thereby rotating the at least one dam such that when the at least one dam unaligns with the at least one outlet fluid is allowed to exit the manifold body through the at least one outlet and when the at least one dam aligns with the at least one outlet fluid is thwarted from exiting the manifold body through the at least one outlet.

2. The device as claimed in claim 1, wherein the at least one propelling vane is mounted on the selector cam in a position proximal to the fluid inlet.

3. The device as claimed in claim 1, wherein the manifold body has an inner surface having a circumference and the at least one dam has an arc-like shape that cooperates with the inner surface of the manifold body.

4. The device as claimed in claim 3, wherein the at least one outlet has a diameter and the at least one dam has a height of at least the diameter of the outlet.

5. The device as claimed in claim 4, wherein the at least one dam has an arc length of less than the circumference of the inner surface of the manifold body.

6. The device as claimed In claim 4, wherein the at least one dam has an arc length of up to about one-half the circumference of the inner surface of the manifold body.

7. The device as claimed in claim 4, wherein the at least one dam has an arc length of approximately one-quarter the circumference of the inner surface of the manifold body.

8. A device for producing a pulsating waterjet comprising;

a manifold body having a hollow Interior, a fluid inlet, and a plurality of outlets leading from the hollow interior and fluidly connecting the hollow interior to at least one waterjet; and

a selector cam having at least one propelling vane and a plurality of dams that cooperate with the outlets so as to sequentially align with and unalign with the outlets,

whereby fluid entering the manifold body through the fluid inlet impinges upon the at least one propelling vane imparting rotational motion to the selector cam and the dams thereby rotating the dams such that when each of the dams unaligns with a cooperating outlet fluid is allowed to exit the manifold body through the cooperating outlet and when each of the dams aligns with the cooperating outlet fluid is thwarted from exiting the manifold body through the cooperating outlet.

9. The device as claimed in claim 8, wherein the at least one propelling vane is mounted on the selector cam in a position proximal to the fluid inlet.

10. The device as claimed in claim 8, wherein the manifold body has an inner surface having a circumference and the dams have an arc-like shape that cooperates with the inner surface of the manifold body.

11. The device as claimed in claim 10, wherein the outlets have a diameter and the dams have a height of at least the diameter of the outlet.

12. The device as claimed in claim 11, wherein the dams have an arc length of less than the circumference of the inner surface of the manifold body.

13. The device as claimed in claim 11, wherein the dams have an arc length of up to about one-half the circumference of the inner surface of the manifold body.

14. The device as claimed in claim 11, wherein the dams have an arc length of approximately one-quarter the circumference of the inner surface of the manifold body.

15. The device as claimed In claim 8, further comprising at least one row of the outlets located longitudinally on the manifold body.

16. The device as claimed In claim 8, wherein a set of two dams is located at a specific location along the selector cam such that each of the two dams in the set of two dams cooperates with one of the outlets.

17. The device as claimed In claim 8, further comprising at least two rows of the outlets located longitudinally on the manifold body, wherein at least two of the outlets are located the same longitudinal distance along the manifold body relative to the fluid inlet.

18. The device as claimed in claim 17, wherein a set of two dams is located at a specific location along the selector cam such that each of the two dams in the set of two dams cooperates with both of the two outlets that are located the same longitudinal distance along the manifold body relative to the fluid inlet.

19. The device as claimed in claim 17, wherein the at least two rows of the outlets are located diametrically opposed from each other across a central axis of the manifold body.

20. A device for producing a pulsating waterjet comprising:

a manifold body having a hollow interior, an inner surface having a circumference, a fluid inlet, and a plurality of outlets arranged in at least one row located longitudinally on the manifold body, the outlets leading from the hollow interior and fluidly connecting the hollow interior to at least one waterjet; and

a selector cam having at least one propelling vane and a plurality of dams that cooperate with the outlets so as to sequentially align with and unalign with the outlets, wherein the at least one propelling vane is mounted on the selector cam in a position proximal to the fluid inlet and the dams have an arc-like shape that cooperates with the inner surface of the manifold body,

21. The device as claimed in claim 20, wherein the outlets have a diameter and the dams have a height of at least the diameter of the outlet.

22. The device as claimed in claim 21, wherein the dams have an arc length of less than the circumference of the inner surface of the manifold body.

23. The device as claimed in claim 21, wherein the dams have an arc length of up to about one-half the circumference of the inner surface of the manifold body.

24. The device as claimed in claim 21, wherein the dams have an arc length of approximately one-quarter the circumference of the inner surface of the manifold body.

25. The device as claimed in claim 21, wherein a set of two dams is located at a specific location along the selector cam such that each of the two dams in the set of two dams cooperates with one of the outlets.

26. The device as claimed in claim 25, further comprising at least two rows of the outlets located longitudinally on the manifold body, wherein at least two of the outlets are located the same longitudinal distance along the manifold body relative to the fluid Inlet.

27. The device as claimed in claim 21, wherein a set of two dams is located at a specific location along the selector cam such that each of the two dams in the set of two dams cooperates with both of the two outlets that are located the same longitudinal distance along the manifold body relative to the fluid inlet.

28. The device as claimed in claim 27, wherein the at least two rows of the outlets are located diametrically opposed from each other across a central axis of the manifold body.