Portable encapsulated underwater ultrasonic cleaner

Information

  • Patent Grant
  • 6259653
  • Patent Number
    6,259,653
  • Date Filed
    Monday, August 14, 2000
    24 years ago
  • Date Issued
    Tuesday, July 10, 2001
    23 years ago
Abstract
A portable, diver-operated device provides an improved method of cleaning surfaces underwater. The device includes a source of ultrasonic energy in a housing that has a compliant portion around an opening to engage and fit around a contaminated surface and clean it with the ultrasonic energy. The housing is made from material that diminishes transmission of the ultrasonic energy to ambient water. The compliant portion seals the source, the contaminated surface and some water from ambient water to concentrate the cleaning power of the source on the surface and to prevent transmission of harmful levels of energy outside of the device and through ambient water.
Description




BACKGROUND OF THE INVENTION




This invention relates to cleaning devices for underwater surfaces. More particularly, the cleaning device of this invention is portable by a diver and uses ultrasonic energy to clean contamination from surfaces underwater.




Underwater surfaces are cleaned, or otherwise prepared by a number of methods. Many of these methods use brushes, scrapers and/or water-jets for abrasive cleaning and surface preparation that include rust and scale removal, paint and coating removal, and marine growth removal. The support systems for these methods are too large and heavy to be carried by a single diver, and they usually require operational support from equipment located on the surface. Consequently, they are not truly portable and their use may attract unwanted attention. In addition, the systems consume large quantities of power and are expensive.




Ultrasonic energy has been widely used commercially in baths in open sinks at surface installations for measurement, protection, and cleaning operations. Ultrasonic energy is transmitted through the unsealed open baths that may include cleaning, or abrasive solutions to effectively clean parts; however, the sinks are inefficient and relatively bulky fixed structures and by their very nature cannot be used to clean surfaces underwater.




A commercially available tool marketed under the trademark SONICATOR by MISONIX Incorporated of 1938 New Highway, Farmingdale, N.Y., 11735 has shown promise for underwater cleaning of some contaminants (grease, dirt, grime, hardened thread locking compound, etc.) from parts. It has a one-half inch diameter probe-like tip that is brought about one-half inches from or in contact with contaminated surfaces on the parts. Compared to topside standard sinks that use ultrasonic energy, the power (550 watts at 20 kHz) of the probe-like tool was found to clean the parts about ten times faster, but it did not remove marine barnacle and mollusk shell growth except to clean the surfaces of the growth. In addition, the mid-frequency noise levels that were generated by cavitation bubble formation on the tip of the probe were appreciable and are likely to be unacceptable when used near some sensors and ordnance.




Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for an ultrasonic cleaner portable by a diver-operator that seals a surface to be cleaned from ambient water and retains ultrasonic energy to clean the surface underwater.




SUMMARY OF THE INVENTION




The present invention provides an underwater tool that includes a source of ultrasonic energy in a shell-shaped housing having an opening to engage and fit around a surface to clean the surface with the ultrasonic energy. The shell retains the ultrasonic energy inside of it and a compliant portion around the opening seals the source of ultrasonic energy, the surface, and some water from the ambient water. The invention also includes a method of cleaning a surface underwater using the underwater tool.




An object of the invention is to provide a method of and device for using ultrasonic energy to clean a surface underwater.




Another object is to provide a method of and portable device for cleaning an underwater surface that seals the surface and an ultrasonic energy source from ambient, or surrounding water.




Another object is to provide a method of and portable device for cleaning an underwater surface that seals the surface, an ultrasonic energy source and some liquid from ambient water.




Another object is to provide a method of and device for cleaning an underwater surface that diminishes transmission of energy to ambient water.




Another object is to provide a method of and portable device for cleaning an underwater surface having a housing made from material absorptive of ultrasonic energy to reduce the level of energy transmitted to ambient seawater.




Another object is to provide a method of and portable device for cleaning an underwater surface having a housing with an internal coating to reduce the level of energy transmitted to ambient seawater.




Another object is to provide a method of and portable device for cleaning an underwater surface having a housing with an internal reflective coating to reflect energy in a chamber to enhance cleaning.




Another object of the invention is to provide a method of and device for cleaning a surface underwater using a dish-shaped shell having at least a compliant portion around an opening to retain ultrasonic energy and seal a source of ultrasonic energy, the surface and some water in a chamber from ambient water.




These and other objects of the invention will become more readily apparent from the ensuing specification when taken in conjunction with the appended claims.











BRIEF DESCRIPTION OF THE DRAWINGS




The FIGURE is a schematic representation of the device of the invention shown partially in cross section for cleaning contaminants from a surface underwater.











DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to the FIGURE, cleaning device


10


is portable by a diver-operator and can be deployed at various depths in water


20


to clean a surface


30


of contaminants


31


. Surface


30


can be metal (or other materials) of undersea structural components, instrumentation packages, sensors, ordnance, etc. Contaminants


31


can include fouling caused by marine growth including barnacle shells, mollusk shells, plus a host of other marine growth and organisms, and/or a number of chemical compounds such as rust, scale, sand, grease, dirt, grime, etc.




Cleaning device


10


has a waterproof container


40


and is sized to be portable by a diver, although larger versions of cleaning device


10


may need more than one diver to transport it. Container


40


can have a handle


40




a


at one end for carrying and positioning it, and an essentially dish-shaped shell, or housing


11


functioning as a conformal enclosure is mounted on the other end of container


40


.




One configuration of shell-shaped housing


11


has an annular lip-shaped portion


12


around opening


13


. Annular portion


12


is made from a material that is compliant enough to pliably conform to surface


30


and contaminants


31


as it engages them to seal a chamber


14


inside housing


11


and adjacent to surface


30


and contaminants


31


.




A source of ultrasonic energy


15


is disposed in chamber


14


to project, or transmit ultrasonic energy


16


. The projected energy usually passes through some water


21


that has been part of ambient water


20


before cleaning device


10


was placed on surface


30


and contaminants


31


.




Housing


11


and annular portion


12


can be integral with each other and can be formed as a molded elastomeric unit. A preferred choice is polyurethane as an elastomeric material that assures sealing, and another good choice is compliant natural rubber. Other natural and manmade materials can be used as long as they are compliant enough to conform to surface


30


and its contaminants


31


to seal chamber


14


from surrounding, or ambient water


20


. The compliant seal created by annular portion


12


seals source


15


, surface


30


and contaminants


31


and some water


21


from ambient water


20


to concentrate the cleaning power of ultrasonic energy


16


from source


15


on contaminants


31


on surface


30


in chamber


14


. The compliant seal created by annular portion


12


also prevents transmission of harmful levels of ultrasonic energy


16


and mid-frequency energies outside of housing


11


of cleaning device


10


.




In addition, the chosen material for housing


11


and portion


12


has suitable properties of absorption of ultrasonic energy


16


in the range of about 20 to 35 kHz. and mid-frequency noise in the range of about 10 to 1500 Hz. A material of such absorptional properties will serve to isolate, or at least diminish the transmission of portions of ultrasonic energy


16


and mid-frequency noise from chamber


14


to ambient water


20


. The undesirable mid-frequency noise is generated largely due to the formation and/or collapse of cavitation bubbles during projection of ultrasonic energy


16


from source


15


within chamber


14


. The compliant material, natural rubber, has such properties of absorption. The lead-impregnated vinyl material designated DSB-1 marketed under the trademark QUIET MAT by Noise Reduction Enterprises, Marine Products Division, Essex, Mass. 01929-0907 is another satisfactory sound absorbing material Other natural and manmade materials can be used as well.




A septum or suitable coating


17


can be provided on the inside of housing


11


and annular portion


12


in chamber


14


to reflect portions of ultrasonic energy


16


(and possibly mid-frequency energy) back onto surface


30


and contaminants


31


in chamber


14


in addition to reflections of other portions of ultrasonic energy (and possibly mid-frequency energy) caused by housing


11


. The shape of housing


11


reflects energy onto surface


30


and contaminants


31


. However, housing


11


can have different shapes, such as curved, or cone-shaped to improve reflection of ultrasonic energy from coating


17


onto surface


30


and can help focus ultrasonic energy onto surface


30


. These features help reduce transmission of possibly harmful levels of energy to the operator of cleaning device


10


and other unwanted listeners. The energy reflected can add to the process of cleaning contaminants


31


from surface


30


.




Housing


11


may be made from different materials than portion


12


when enhancement of different properties may be called for, for example, when a larger cleaning unit for larger surfaces needs a material that has additional structural strength. However, these different materials enhance the isolation, or at least diminishment of the transmission of ultrasonic energy


16


from chamber


14


to ambient water


20


, as compared to the material used in annular portion


12


that is likely to be primarily selected for its compliant properties to seal chamber


14


from ambient water


20


. In this configuration, material of housing


11


could be the material DSB-1 marketed under the trademark QUIET MAT by Noise Reduction Enterprises, and annular portion


12


could be compliant polyurethane, although other suitable materials might be selected as well




Source


15


of ultrasonic energy can be a piezoelectric transducer appropriately driven to provide suitable levels of projected, or transmitted ultrasonic energy


16


. Many different piezoelectric transducers available in the art are acceptable. The frequency and ranges of frequency of the projected signals of ultrasonic energy


16


and the power of the signals of the projected energy from the selected transducers can be selected and tuned by modular components to be identified below. Thus, cleaning of different contaminations


31


on surface


30


can be optimized, and cleaning times can be reduced.




Optionally, source


15


can include a plurality, or an array of piezoelectric transducers in chamber


14


. The signals projected from the transducers can be phased in accordance with known phasing techniques to focus a composite form of ultrasonic energy


16


onto surface


30


and contaminants


31


. This capability assures thoroughness and rapid completion of the cleaning process. Individual ones of the selected transducers or arrays of from one to five transducers typically project levels of ultrasonic energy, or power from source


15


that range from 500 to 2500 watts. This creates typical, or exemplary levels of power concentration of about 31 to 156 watts per cubic inch in a four-inch diameter, or sixteen cubic inch volume chamber


14


.




Housing


11


has a shank portion


11




a


coupling it to sealed container


40


and transmitting electrical power to drive each transducer of source


15


via leads


11




a


′. Shank portion


11




a


may also have hydraulic and/or mechanical links and couplings (not shown) between container


40


and source


15


. Container


40


is sealed and waterproof and encapsulates battery module


41


, signal generator module


42


, power amplifier module


43


and impedance matching module


44


that may also be individually sealed units and are operatively connected together via connections (not shown) to deliver suitable power to drive source


15


.




Battery module


41


delivers sufficient, selectable levels of power to the other modules when a waterproof dial-type switch


41




a


, for example, is actuated by a diver-operator. Signal generator module


42


produces ultrasonic signals in preselected frequencies and ranges when appropriately tuned by an operator via waterproof dial-type tuning switch


42




a


, for example. The selected ultrasonic signals are amplified in power amplifier stage


43


, and fed to impedance matching module


44


where maximum power transfer to transducer


15


is provided for. These modules and their tuning features are known in the art, and one of ordinary skill in the art to which this invention pertains will readily fabricate or select suitable modules and their tunable features from commercial sources.




As a further option, source


15


could be only a radiating, or projection structure in chamber


14


. The rest of the transducer could be contained inside container


40


with mechanical or hydraulic couplings through shank


11


a that link the transducer to projection structure of source


15


. This option may allow more powerful transducers to create higher levels of cleaning power.




In operation, cleaning device


10


is so compact and portable that it can be carried by a diver-operator to a remote, underwater work site where surface


30


is to be cleaned of contaminants


31


. Grasping handle


40




a


and a portion of container


40


, the diver places annular portion


12


against and around surface


30


and contaminants


31


and exerts a slight pushing, or pressing force. This pressing force holds cleaning device


10


against surface


30


and contaminants


31


and slightly deforms the compliant material of annular portion


12


. Annular portion


12


pliably accommodates, or engages surface


30


and contaminants


31


to seal source


15


, surface


30


and contaminants


31


, and some water


21


in chamber


14


from ambient water


20


. The diver may add some abrasive, or other cleaning additive


22


to water


21


in chamber


14


from a syringe-like applicator or packet to assist the cleaning process, if desired.




Source


15


of ultrasonic energy is activated by the diver's actuation of switch


41




a


. Ultrasonic energy


16


from source


15


is projected from source


15


into water


21


in chamber


14


and onto contaminants


31


. The relatively small size of chamber


14


serves to concentrate projected ultrasonic energy


16


from source


15


onto surface


30


and contaminants


31


. Typically, concentrated levels of ultrasonic energy in the range of 31 to 156 watts per cubic inch are suitable to remove most contaminants


31


, and these levels can be transmitted by suitable control of switch


41




a.






Another factor to consider in the removal of contaminants is selection of frequencies of ultrasonic energy


16


. Different frequencies of projected ultrasonic energy


16


can affect the efficiency of removal of contaminants


31


and may be generated in signal generator module


42


. They are selected or tuned by the diver's control of tuning switch


42




a


. The selected composition and power of ultrasonic energy


16


are projected from source


15


into chamber


14


and onto surface


30


and contamination


31


. Ultrasonic energy


16


, as well as mid-frequency noise generated by cavitation bubbles are retained or isolated, or at least diminished from transmission to ambient water


20


by the material of housing


11


. The shape of housing


11


and coating


17


reflect portions of projected ultrasonic energy


16


toward surface


30


and contaminants


31


to assist, or enhance the cleaning process and reduce the problems associated with unwanted transmissions of such energy through ambient water


20


.




Having the teachings of this invention in mind, modifications and alternate embodiments of this invention may be adapted. Cleaning device


10


can be made in larger or smaller sizes, and housing


11


could be made from many other elastomeric materials. Housing


11


could be block-shaped and define a chamber


14


having an annular portion


12


, or other configurations instead of shell-shaped. Levels of power projected by source


15


may be increased or decreased to clean contaminants


31


from differently sized surfaces


30


, or different contaminants


31


from different surfaces


30


at different depths as well. Generation of different power levels and spectral compositions thereof, and the components necessary to produce them will be apparent to one skilled in the art to which this invention pertains.




The disclosed components and their arrangements as disclosed herein all contribute to the novel features of this invention. Cleaning device


10


of this invention is a portable, cost-effective tool to reliably clean contaminants


31


from surfaces


30


underwater without transmitting levels of energy that could be harmful to operators or reveal the nature of the undersea activity. Therefore, cleaning device


10


, as disclosed herein is not to be construed as limiting, but rather, is intended to be demonstrative of this inventive concept.




It should be readily understood that many modifications and variations of the present invention are possible within the purview of the claimed invention. It is to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.



Claims
  • 1. An underwater tool including a source of ultrasonic energy in a housing having an opening to engage and fit around a surface to clean said surface with said ultrasonic energy, said tool being sized to be hand-held and used by a diver underwater, said housing including a dish-shaped shell having a compliant portion around said opening, said compliant portion preventing transmission of harmful levels of said ultrasonic energy and mid-frequency noise outside of said housing, and said housing and said compliant portion having properties to absorb said ultrasonic energy and said mid-frequency noise.
  • 2. An underwater tool according to claim 1 wherein said compliant portion pliably engages said surface and contaminants thereon.
  • 3. An underwater tool according to claim 2 wherein said shell retains said ultrasonic energy in said housing and said compliant portion pliably engaging said surface and said contaminants seals said source of ultrasonic energy, said surface, said contaminants, and some water from ambient water.
  • 4. An underwater tool according to claim 3 wherein said shell, compliant portion, said surface, and said contaminants create a chamber.
  • 5. An underwater tool according to claim 4 wherein said source of ultrasonic energy includes at least one piezoelectric transducer in said chamber, and said shell diminishes transmission of said ultrasonic energy to said ambient water.
  • 6. An underwater tool according to claim 5 further including interconnected power supply, signal generator, power amplifier, and impedance matching modules coupled to said transducer.
  • 7. An underwater tool according to claim 6 wherein said power supply module, signal generator module, power amplifier module, and impedance matching module are contained in at least one watertight container.
  • 8. An underwater tool including a source of ultrasonic energy in a housing having an opening to engage and fit around a surface to clean said surface with said ultrasonic energy, said housing including a dish-shaped shell having a compliant portion around said opening, said compliant portion pliably engaging said surface and contaminants thereon, said shell retaining said ultrasonic energy in said housing, said compliant portion pliably engaging said surface and said contaminants to seal said source of ultrasonic energy, said surface, said contaminants, and some water from ambient water, said shell, compliant portion, said surface, and said contaminants creating a chamber, said source of ultrasonic energy including at least one piezoelectric transducer in said chamber, said shell diminishing transmission of said ultrasonic energy to said ambient water; interconnected power supply, signal generator, power amplifier, and impedance matching modules coupled to said transducer, said power supply module, signal generator module, power amplifier module, and impedance matching module being contained in at least one watertight container; and a cleaning additive in said chamber to enhance cleaning of said contaminants from said surface.
  • 9. An underwater tool according to claim 8 further including a plurality of transducers in said chamber phased to focus ultrasonic energy therefrom onto said contaminants and said surface.
  • 10. An underwater tool according to claim 9 wherein said housing has a coating to reflect energy onto said contaminants and said surface.
  • 11. An underwater tool according to claim 10 wherein said housing is shaped to focus energy onto said contaminants and said surface.
  • 12. An underwater tool according to claim 4 wherein said source of ultrasonic energy includes a radiating structure in said chamber coupled to a transducer in a watertight container.
  • 13. A method of cleaning contaminants from a surface underwater comprising the steps of:providing a source of ultrasonic energy in a shell-shaped housing; placing said shell-shaped housing over a surface and contaminants underwater; sealing said source, said surface, said contaminants and some water from ambient water in said housing; and projecting ultrasonic energy from said source to said surface and said contaminants.
  • 14. A method according to claim 13 wherein said step of sealing comprises the steps of:providing at least an annular portion of compliant material around an opening in said housing; pressing said compliant annular portion against said surface and contaminants thereon; pliably engaging said surface and contaminants with said compliant annular portion; and preventing transmission of harmful levels of said ultrasonic energy and mid-frequency noise outside of said housing by said compliant portion.
  • 15. A method of cleaning contaminants from a surface underwater comprising the steps of:providing a source of ultrasonic energy in a shell-shaped housing; placing said shell-shaped housing over a surface and contaminants underwater; sealing said source, said surface, said contaminants and some water from ambient water in said housing; said step of sealing comprises the steps of: providing at least an annular portion of compliant material around an opening in said housing; pressing said compliant annular portion against said surface and contaminants thereon; and pliably engaging said surface and contaminants with said compliant annular portion; projecting ultrasonic energy from said source to said surface and said contaminants; and diminishing transmission of energy through absorptional material of said housing to said ambient water.
  • 16. A method according to claim 15 wherein said step of projecting includes the step of transmitting said ultrasonic energy through a chamber in said housing to said surface and said contaminants.
  • 17. A method according to claim 16 further comprising the step of:reflecting portions of energy from a coating in said chamber to said surface and said contaminants.
  • 18. A method according to claim 17 further comprising the step of:shaping said housing to reflect portions of said energy in said chamber to said surface and said contaminants.
  • 19. A method according to claim 18 further comprising the step of:adding a cleaning additive to water in said chamber to aid cleaning of said contaminants from said surface.
  • 20. A method according to claim 19 wherein said step of projecting includes the step of driving a piezoelectric transducer with electrical power to produce said ultrasonic energy.
  • 21. A method according to claim 20 further comprising the step of:providing interconnected power supply, signal generator, power amplifier, and impedance matching modules for said transducer in a watertight container.
  • 22. A method according to claim 21 wherein said steps of diminishing, reflecting, and shaping affect ultrasonic and mid-frequency energies.
  • 23. A method according to claim 19 wherein said step of projecting includes the step of driving a radiating structure in said chamber to project ultrasonic energy by a transducer disposed in said container.
  • 24. A device for cleaning a surface underwater comprising:a shell-shaped housing having a chamber and a compliant portion around an opening to pliably engage a surface and contaminants thereon; at least one piezoelectric transducer to project ultrasonic energy in said chamber to clean said contaminants from said surface with said ultrasonic energy, said housing diminishing transmission of said ultrasonic energy and mid-frequency energy therethrough to ambient water, and said pliable engagement of said surface and said contaminants by said compliant portion sealing said source of ultrasonic energy, said surface, said contaminants, and some water in said chamber from ambient water; a watertight container containing interconnected power supply, signal generator, power amplifier, and impedance matching modules coupled to said transducer; a cleaning additive in said chamber to enhance cleaning of said contaminants from said surface; and a coating in said chamber to reflect energy onto said contaminants and said surface.
  • 25. A device according to claim 24 further comprising:a plurality of transducers in said chamber phased to focus ultrasonic energy therefrom onto said contaminants and said surface, and said housing being shaped to focus ultrasonic energy onto said contaminants and said surface.
STATEMENT OF GOVERNMENT INTEREST

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

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4444146 De Witz et al. Apr 1984
4890567 Carduff Jan 1990
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