1. Field of the Invention
The present invention relates generally to mechanical oscillators for water cannons, such as those used to deliver high volume, high pressure fluid for applications such as fire suppression. More specifically, the invention relates to a water powered waterway oscillator that can change oscillation modes between continuous circular mode and alternating rotational mode.
2. Description of Related Art
Water cannons, also known as fire monitors and deluge guns, have been an effective tool in fire suppression systems for many years. Water cannons are designed to deliver a high pressure stream of fluid through a nozzle to saturate a desired area with large volumes of water, foam, or other fire suppressant. Most water cannons tend to be heavy apparatus, usually portable only by boat or truck, that are made essentially stationary when in use. Water cannons can be manually aimed, for example, by a fireman directing water into a burning building or into a crowd for riot control. Or, a water cannon may be locked into position and unmanned, to deluge an area without requiring the presence of an operator. This allows a single operator to move between multiple water cannons, adjusting their aim as necessary to suppress the fire. In other uses, an unmanned water cannon may be set up to douse a wide area of brush or other combustible debris for a prolonged period in advance of an oncoming wild fire, or it may be set up in a dry area to suppress dust and preserve visibility.
Water cannons may also be made to oscillate by providing a means for automatically moving the nozzle, or by automatically moving the waterway that connects to the nozzle. One type of oscillating water cannon uses a continuous circular oscillator that rotates in a 360 degree circular pattern. Another type of oscillating water cannon alternates its rotational direction (clockwise, counterclockwise, clockwise, etc.) as it sweeps back and forth though a circular arc. Either type of oscillator may be powered from an external source, such as an electric or hydraulic motor, or it may be powered using pressure in the flow of main fluid.
Externally powered water cannon oscillators are unsuitable in many applications. For example, electric power may not be available in a remote or undeveloped location, such as a desert or national park. Or an external power source may be rendered unavailable as a result of the same catastrophe, such as an earthquake or industrial accident, that caused the fire against which the water cannon must be deployed. And in general, it may be undesirable to introduce into a fire zone a combustible, petroleum-based fluid needed for operating a hydraulic motor.
Water-powered oscillators address these problem, but introduce another. State-of-the-art water-powered water cannon oscillators generally fall into two categories: continuous circular oscillators and alternating rotational oscillators. The choice of oscillator depends on the circumstances of use. For fire suppression in a burning building, an alternating rotational oscillator would allow a water cannon stationed in an adjacent street to sweep back and forth along a desired angle, e.g. 120 degrees, to deluge the building most effectively. For dust suppression near a remote landing strip, a continuous circular oscillator would allow a water cannon to deluge the maximum possible area. The problem with using water power to cause oscillation is that, unlike a controllable electric motor, a water-powered oscillating system cannot be programmed to change oscillating modes from continuous circular to alternating rotational.
To change the oscillating mode of a water-powered oscillator, a technician would need to modify the system to install a different driving mechanism, which is time-consuming and which introduces risk of injury to personnel and damage to equipment when removing pins, disconnecting flanges, etc. End users must therefore either double their inventory of water cannon oscillators, or suffer the inconvenience of having to mechanically reconfigure their oscillators in the field. What is needed is a waterway oscillator that can be very easily manipulated in the field to change its oscillating mode.
The present invention provides an engineering design for a waterway oscillator that directs a high power, high pressure flow of fluid such as water through an outlet for industrial applications such as fire suppression. The waterway oscillator is configured to switch oscillating modes between circular oscillation in one rotational direction, and an alternating rotational oscillation between selectable end points of a circular arc. The invention is further characterized by a mechanical configuration that diverts a portion of main fluid flow through a control port to serve as the motive force for causing either mode of oscillation.
In one embodiment, a water-powered multi-mode waterway oscillator includes a main conduit directing a main flow of water and having a fixed end and a rotatable end, and a driven gear fixed or coupled to the rotatable end. A control conduit redirects a portion of the main flow from the main conduit to provide an auxiliary flow to a control outlet. A waterwheel is positioned to receive the auxiliary flow, and is configured to rotate a drive shaft in response to impact of water from the control outlet. A main drive gear is coupled to the drive shaft so that it rotates continuously in response to the auxiliary flow. A rotatable engagement arm is positioned above the main drive gear and configured to rotate between first and second engagement positions. The engagement arm has first and a second ends. A continuous drive gear is rotatably pinned to the first end and configured to engage the main drive gear and the driven gear. An oscillating drive gear is coupled to the drive shaft, rotatably pinned to the second end, and configured to engage the driven gear. A means for translating the engagement arm between the first and second positions is mounted to the waterway oscillator so that in the first position, the continuous drive gear engages the main drive gear and the driven gear to cause continuous rotation of the rotatable end of the main conduit, and so that in the second position, the oscillating drive gear engages the driven gear to cause alternating rotation of the rotatable end of the main conduit.
A waterway oscillator according to the invention may be enhanced with various additional features as follows: The main conduit may be configured for attachment to a water cannon nozzle. A flow control valve may be installed between the main conduit and the control outlet. The waterwheel may be coupled to the drive shaft through gear reduction. The main drive gear may be concentrically coupled to the drive shaft. The engagement arm may be located so that its center of rotation is concentric with the main drive gear.
A waterway oscillator according to the invention may be further characterized by its mechanism for providing alternating rotational oscillation. The oscillating drive gear may have a geared end and a driving end and may be pinned to the second end of the engagement arm at a pivot point between the geared end and the driving end. A pivot drive arm may be coupled to an end of the drive shaft and extend perpendicularly therefrom. A push rod having a proximal end coupled to the pivot drive arm at a point displaced from the end of the drive shaft and having a distal end coupled to the driving end of the oscillating drive gear converts continuous rotating motion of the drive shaft into alternating rotational motion of the oscillating drive gear about the pivot point. The pivot drive arm may include a means for adjusting displacement of the proximal end of the push rod from the end of the drive shaft to change rotational span of the oscillating drive gear.
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. Component parts shown in the drawings are not necessarily to scale, and may be exaggerated to better illustrate the important features of the invention. Dimensions shown are exemplary only. In the drawings, like reference numerals may designate like parts throughout the different views, wherein:
The following disclosure presents an exemplary embodiment for a water powered multi-mode waterway oscillator according to the present invention. The embodiments depicted and described herein are intended to deliver a high power, high pressure flow of water through a flanged outlet configured for connecting to a nozzle or water cannon. So configured, the waterway oscillator may be employed most effectively for industrial applications such as fire and dust suppression. The inventive features of the waterway oscillator allow it to switch oscillating modes between (1) circular oscillation in one rotational direction, and (2) alternating rotational oscillation between selectable end points of circular arc. The invention is further characterized by a mechanical configuration that diverts a portion of main fluid flow through a control port to serve as the motive force for causing either mode of oscillation.
The waterway oscillator 100 is generally characterized by a main conduit 10 that directs a main flow of water 12 from a fixed end 14 of the main conduit, toward a rotatable end 16 of the main conduit. Rotatable end 16 may be coupled to fixed end 14 by means of a bearing or bearing structure that allows the rotatable end to swivel or rotate with respect to the fixed end 14. The rotational direction of rotatable end 16 lies in a plane normal to the vertical direction of flow 12 and about an axis that is concentric with the main conduit. Each of the fixed and rotatable ends 14 and 16 may be configured as flanged pipe fittings, as shown, to facilitate connection to other components of a water delivery system. In one embodiment, the main conduit may comprise a 4-inch pipe, with flanged ends rated in the 150# pressure class.
A protective cover 18 may be mounted to the main conduit 10 to protect personnel from moving parts of the internal oscillating mechanisms, and to provide a barrier against weather and foreign material intrusion. A shield 20 may be mounted to the protective cover to provide similar protections for the mechanical control system.
Waterway oscillator 100 may also be equipped with manual controls. A mode-selecting knob 22 allows an operator to change the oscillating mode by turning the knob 22 clockwise or counterclockwise. A hand wheel 24 allows the operator to open a control valve and divert a portion of the main flow 12 to the mechanical control system to energize the oscillator and cause the rotatable end 16 to oscillate according to the selected mode.
A control valve 30 may be placed between control port 26 and a downstream control outlet, to regulate flow through the control conduit, or to turn the flow off and shut down the oscillators. Control valve 30 may be of any conventional design, such as a globe or gate valve, that is rated to withstand main conduit pressure and designed for compliance with an appropriate industrial code or standard such as an NFPA standard. Control port 26, control conduit 28, and control valve 30 may be configured for attachment by means of conventional pipe fittings, such as threaded, welded, swage, and compression fittings.
On the downstream side of control valve 30, an additional length of conduit extends a short distance from the control valve and terminates in a control outlet 34 at the entrance into shield 20. It should be appreciated that control valve 30 is an optional component, and may be eliminated from the design in certain embodiments of the invention, such that conduit 28 may be extended until terminating at the control outlet 34. The inclusion of control valve 30, however, may provide an operator with a means to throttle the speed of the mechanical oscillators.
A waterwheel 42 equipped with a plurality of blades around its perimeter is suspended from the mechanism and positioned to receive the auxiliary flow 32 as it exits the control outlet 34. A nozzle 44 may be attached to the control outlet to accelerate and direct the auxiliary flow so that it impacts the blades of waterwheel 42 in such a way so that it maximizes energy transfer from the auxiliary flow to the waterwheel. In one embodiment, waterwheel 42 may be a Pelton wheel. The impact of fluid jetting from control outlet 34 onto the blades of the waterwheel causes the waterwheel to rotate, which from the perspective shown would be in a clockwise direction. After impacting the waterwheel, the auxiliary flow of water may be allowed exit the mechanism by spilling to the ground.
In one embodiment, the rate of auxiliary flow that impacts the waterwheel 42 may be between about 5 and about 10 gpm, causing the waterwheel to rotate at between about 1650 and 1750 rpm. Waterwheel 42 includes a central shaft that is connected to an input side of a gear box 46. Any type of gear box, such as one containing worm gears or planetary gears, or some combination of the two, may be employed within the scope of the invention. Gear box 42 may be designed for gear reduction to lower the speed and increase the torque delivered to the output or drive shaft 48 of the gear box. By way of example, a gear ratio in the range of about 200:1 to 400:1 should produce sufficient torque to move the driven gear 40 of the main conduit 10 at a speed in the range of about 4 to about 6 cycles per minute.
The drive shaft 48 of gear box 42 extends through the top of the gear box, where it connects to a main drive gear 50, so that rotation of the drive shaft causes rotation of the main drive gear. In the embodiment shown, main drive gear 50 is fixed concentrically to drive shaft 48, though other configurations are possible. During proper operation, as long as main flow 12 provides a continuous source for auxiliary flow 32, and provided that control valve 30 passes a sufficient amount of the auxiliary flow, waterwheel 42 will drive the gear box and cause drive shaft 48 to rotate main drive gear 50 continuously. The continuous rotation of the main drive gear provides the motive force required to oscillate the waterway in either rotational mode.
In circular oscillation mode, the continuous rotation of main drive gear 50 may be transmitted to the driven gear 40 when a continuous drive gear 52 is moved to a position so that it engages both the driven gear 40 and the main drive gear 50. In alternating rotational oscillation mode, the driven gear 40 may be oscillated back and forth between end points of a circular arc when engaged by an oscillating drive gear 54. The oscillating drive gear 54 derives its alternating motion from the continuous rotation of main drive gear 50, as explained below in further detail.
An engagement arm 56, which may be mounted above continuous drive gear 50, may be employed to move the continuous drive gear 52 or the oscillating drive gear 54 into a position for engaging the driven gear 40. In the present embodiment, engagement arm 56 is rotatable, and supports the two drive gears at different locations, so that one or the other of the drive gears may be rotated into an engagement position with driven gear 40. The engagement arm 56 may be rotated manually by means of mode-selecting knob 22.
The rotatable engagement arm 56 may be configured with a first end 58 and a second end 60. The first end supports the continuous drive gear 52, and the second end supports the oscillating drive gear 54. The first and second ends each extend from a central pivot point 62 on engagement arm 56, forming an angle between the two ends. In the embodiment shown, the angle between the two ends is about 90 degrees. In other embodiments of the invention, this angle may be greater than or less than 90 degrees. Although the first and second ends are shown in this embodiment as elongated members extending from a central hub of a generally planar engagement arm, other configurations of an engagement arm are possible. Functionally, the engagement arm must be able to assume a first position in which only the continuous drive gear 52 engages the driven gear, and assume a second position in which only the oscillating drive gear 54 engages the driven gear.
To effect rotation of the first and second ends 58 and 60 about the pivot point 62, the rotatable engagement arm 56 may be configured with a third end 64 that rotates the engagement arm in response to motive force from a translating means. One example of a translating means includes the mode-selecting knob 22 that is shown throughout the drawings. Knob 22 may be connected to a rod or shaft 66 that is passed through the protective cover 18 and a support plate 68. Shaft 66, at its end opposite the mode-selecting knob, may be at least partially threaded, with the threaded end engaged within complimentary threading of a block 70. Block 70 may be pinned to the third end 64 of the engagement arm 56, so that rotation of shaft 66 draws block 70 either toward or away from the mode-selecting knob, causing rotation of the engagement arm 56 about its pivot point 62. Shaft 66 need not be threaded; however, by using a shaft threaded with proper tolerances, the position of block 70 and also the position of engagement arm 56 will remain fixed until an operator manually adjusts the mode-selecting knob. One or more bearings 69 and appropriate fastening hardware may be used to rotatably mount the shaft 66 through the support plate 68.
Various other means for translating the engagement arm are possible within the scope of the invention. For example, the end of shaft 66 may be fixed to the block 70, and the shaft may be allowed to thread in and out of the support plate 68. Or, an unthreaded shaft 66 may be pushed or pulled through a linear guide to effect rotation of the engagement arm. Or, a lever arm may be connected to the third arm 64, either directly or through some intermediate linkage. Alternatively, the third arm 64 may be extended for direct manipulation by an operator, or an electric or hydraulic motor may be used to rotate the engagement arm. In another embodiment, it is contemplated that a means for translating the engagement arm may comprise a hydraulic system (not shown) that derives motive force from the main flow 12.
The top view of
Push rod 76 may be formed from rectangular or cylindrical bar stock. A proximal end 80 of push rod 76 may be pinned to the end of the pivot drive arm that is opposite pivot point 62, as shown, so that the proximal end 80 rotates in a circle having a radius equal to the distance between the proximal end 80 and pivot point 62. A distal end 82 of push rod 76 may be pinned to a driving arm 84 of the oscillating drive gear 54, and a center point 86 of the oscillating drive gear 54 may be pinned to the second end 60 of rotating arm 56. The oscillating drive gear may be configured to rotate about its center point 86 in response to displacement of its driving arm 84.
The operation of the oscillating drive gear is now described from the perspective of a top view of the mechanism as shown in
The angular span of the oscillating drive gear 54 may be adjusted by temporarily disconnecting the pivot drive arm 72 and sliding it with respect to pivot point 62 so that the top end of the drive shaft 48 is moved to a different position within slot 78. The pivot drive arm may then be re-connected to drive shaft 48 by means of main shaft pivot and 74 and appropriate fastening hardware. In the embodiment shown, the slotted pivot drive arm allows the angular span to be adjusted between about 25 degrees and about 125 degrees. Greater or lesser spans are possible within the scope of the invention.
In the embodiment shown, the proximal end 80 of push rod 76 lies at a higher elevation than the distal end 82, such that the push rod crosses the plane of the engagement arm 56. To prevent interference between the push rod and the engagement arm, a recess 88 may be formed on a side of the second end 60.
A water powered, multi-mode waterway oscillator according to the invention may be used for industrial applications that require flow rates of up to about 3000 gpm and pressures up to about 100 psi. Given these ratings, and the corrosive environment created by the flow of water, materials of construction for the many parts and components described herein are preferably rugged, non-corrosive metals such as stainless steel, plated or coated steel, brass, and aluminum bronze. The design principles of the invention, and the sizes and ratings disclosed herein, may be scaled up or down according to the end use application.
A water powered, multi-mode waterway oscillator according to the invention achieves many objectives and advantages over state of the art waterway oscillators. It uses water pressure as the motive force for oscillating the waterway, so that no hydraulic or electrical energy sources are required for full operation. It provides both continuous rotational and alternating rotational oscillating modes in one control system. And it provides a convenient and easily manipulated manual controls for changing the oscillating mode, for adjusting the speed of oscillation, and for adjusting the angular span of the alternating oscillation.
Exemplary embodiments of the invention have been disclosed in an illustrative style. Accordingly, the terminology employed throughout should be read in a non-limiting manner. Although minor modifications to the teachings herein will occur to those well versed in the art, it shall be understood that what is intended to be circumscribed within the scope of the patent warranted hereon are all such embodiments that reasonably fall within the scope of the advancement to the art hereby contributed, and that that scope shall not be restricted, except in light of the appended claims and their equivalents.