Patent Publication Number: US-7721383-B2

Title: Disinfecting device utilizing ultraviolet radiation

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of U.S. patent application Ser. No. 11/360,045, filed Feb. 22, 2006 now U.S. Pat. No. 7,444,711. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     None 
     REFERENCE TO MICROFICHE APPENDIX 
     Not applicable 
     TECHNICAL FIELD 
     1. Field of the Invention 
     The invention generally relates to using ultraviolet radiation to disinfect various cleaning media. The invention more particularly relates to devices and processes that can be employed to disinfect or sanitize infestation agents within various cleaning media by using ultraviolet radiation. 
     2. Background 
     Many homes and businesses suffer from infestations of allergens and other undesirable organic and inorganic substances, such as molds, viruses, bacteria, and dust mites. Floor coverings such as carpeting in homes and hotels, for example, can contain a high concentration of organic or inorganic substances which create a potentially unhealthy or harmful environmental condition. A common indoor allergen in carpeting and mattresses that can trigger allergy symptoms in humans is the dust mite, a microscopic insect related to spiders. It has been claimed that allergies developed in the early years of a child&#39;s life due to exposure to allergens can result in life-long allergic responses or more serious medical conditions such as asthma. Exposure to mold spores, for example, has been linked to certain types of respiratory illnesses. Long-term exposure to mold may cause asthma or other respiratory problems, even in individuals who are not naturally sensitive or allergic to mold. 
     Conventional cleaning methods do not effectively reduce populations of infestation agents present within carpeting. Standard vacuum cleaners do not sanitize or disinfect carpeting, and vacuuming alone usually removes only a fraction of allergens from carpeting. Typically, steam cleaning is cumbersome, expensive, and may involve the use of chemicals. Also, steam cleaning can leave a carpet and its carpet pad in a wet condition that can support the undesirable growth of molds, mildew, bacteria, or dust mites in or beneath the carpet. As another alternative, chemical powders or dry carpet cleaning powders comprised primarily of chemical pesticides and insecticides may be used to clean carpeting. The potential health and safety hazards associated with such chemical powders, however, often outweigh any benefits that might be obtained by using them. 
     Many experts have suggested that the only solution to dealing with infestation agents in carpeting is to remove existing carpeting altogether and to refrain from using carpeting as a floor covering. However, for many individuals who find carpeting desirable, and for many applications where carpeting is an optimum choice for a floor covering, this is not an acceptable solution. As a result of the inadequacy of conventional carpet cleaning methods, however, carpeting in homes and commercial establishments can become an ideal environment in which dust mites, germs, bacteria, viruses, molds and other pathogens or microorganisms can live, grow, and multiply. 
     In addition, mattresses and other like articles are often afflicted by infestation agents. By the nature of how a mattress is used for rest or sleep, it is frequently in close contact with humans or animals that may shed dead skin, for example, or discard other organic substances that are retained in the mattress. Insects such as dust mites can thrive on this organic matter and quickly develop into a significant population within the mattress. As described above for carpeting, conventional cleaning methods applied to a mattress cannot both safely and effectively reduce populations of infestation agents present within the mattress. 
     It has been discovered that ultraviolet (“UV”) light, particularly in the “C” spectrum (“UVC”), can deactivate the DNA of bacteria, viruses, germs, molds, and other pathogens and microorganisms, thus destroying their ability to reproduce and multiply. UVC light has been used effectively in various applications to disinfect and sanitize hospital rooms, medical clinics, food production facilities, and drinking water. However, existing products and processes have been unable to effectively and safely leverage the benefits of UV light to sanitize infestation agents in cleaning media such as carpeting and mattresses. 
     In view of the problems described above, safe and effective disinfecting devices are needed to address the deficiencies of conventional processes for sanitizing cleaning media such as carpeting and mattresses. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The utility of the embodiments of the invention will be readily appreciated and understood from consideration of the following description of the embodiments of the invention when viewed in connection with the accompanying drawings. 
         FIG. 1  is an exploded three-dimensional view of a disinfecting device structured in association with embodiments of the invention; 
         FIG. 2  is an exploded three-dimensional bottom-to-top view of the light bulb assembly of the device shown in  FIG. 1 ; 
         FIG. 2A  is a perspective view of one embodiment of a lens frame of the device; 
         FIG. 2B  is a perspective view of one embodiment of a lens frame of the device; 
         FIG. 3  is a plan view of a portion of the main housing assembly of the device of  FIG. 1 ; 
         FIG. 4  is an exploded three-dimensional view of a telescopic pole assembly provided in accordance with various embodiments of the invention; 
         FIG. 5  is a schematic cross-sectional view of a portion of a disinfecting device provided in accordance with various embodiments of the invention; 
         FIG. 5A  is a schematic cross-sectional view of a portion of a disinfecting device provided in accordance with various embodiments of the invention; 
         FIG. 6  is a schematic cross-sectional view of a portion of a disinfecting device provided in accordance with various embodiments of the invention; 
         FIG. 7  is a schematic cross-sectional view of a portion of a disinfecting device provided in accordance with various embodiments of the invention; 
         FIG. 8  is an exploded three-dimensional view of a bulb-in-bar assembly provided in accordance with various embodiments of the invention; 
         FIG. 9  is a cross-sectional view of a portion of a disinfecting device provided in accordance with various embodiments of the invention; 
         FIG. 10  is an exploded three-dimensional view of the handle of the device shown in  FIG. 1 ; 
         FIG. 11  shows an exploded three-dimensional view of the device of  FIG. 1  in association with various cleaning medium contact switch assembly embodiments of the invention; 
         FIG. 12  illustrates a partially cut-away, three-dimensional view illustrating aspects of the cleaning medium contact switch assembly embodiments of  FIG. 11 ; 
         FIG. 13  illustrates a three-dimensional view of a portion of a disinfecting device provided in accordance with various embodiments of the invention; 
         FIG. 14A  is a front elevational view of one embodiment of the device; 
         FIG. 14B  is a side elevational view of one embodiment of the device; and 
         FIG. 14C  is a top view of one embodiment of the device. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The invention provides embodiments of cleaning and/or disinfecting devices, and features thereof, which offer various benefits: the devices maximize the disinfection capability of ultraviolet light (“UV light”) by providing mechanisms for enhanced penetration of the UV light into a cleaning medium; the devices offer enhanced various heat dissipation and air flow engineering features that can promote and maintain the safe and advantageous use of UV light bulbs employed by the devices; and the devices may employ multiple and integrated safety mechanisms and systems that promote safe and effective use of the devices;. As described below, embodiments of the invention can be applied effectively for disinfecting infestation agents which reside in cleaning media such as carpeting and mattresses. Cleaning operations such as vacuum cleaning operations, for example, can also be performed in association with certain embodiments of the devices described herein. 
     As applied herein, the term “cleaning medium” includes any area, region, substrate, surface, or other medium that can be acted upon by UV light. Examples of “cleaning media” include, without limitation, carpets, mattresses, furniture, drapery, or other surfaces or media (e.g., hardwood, linoleum, and ceramic tile). The cleaning medium can be horizontal, as in a typical floor or mattress top surface, or vertical or at any other angle, such as with drapery and furniture surfaces. The term “carpet” as used herein includes all floor coverings having fibers, whether looped, tufted, hooked, needlefelt, woven or of other design, indoor or outdoor, of natural or synthetic materials, wall-to-wall or roll goods. 
     The term “infestation agent” may include any organism, microorganism, contagion, pathogen, germ, insect, and/or any other organic or inorganic substance which can be affected by application of ultraviolet radiation, or which can be present on or within a cleaning medium. Examples of “infestation agents” include, without limitation, viruses, bacteria, dust mites, molds, roaches, fleas, bed bugs, spiders, and other insects. 
     With reference to  FIGS. 1 through 4 , various embodiments of the invention may be provided in association with a disinfecting device  102 , which may be structured to combine the functional or structural features of a standard vacuum cleaner in conjunction with an ultraviolet light disinfecting apparatus. In certain embodiments, the device  102  may be structured for use as a combination cleaning and disinfecting device, in which both a disinfecting operation and a vacuum cleaning operation are performed by using the device  102 . In various embodiments, the device  102  may be structured to perform disinfecting operations, with or without the additional capability to perform vacuum cleaning operations. Further, the device may be configured to selectively perform both disinfecting and vacuum cleaning operations or either operation independently. 
     The device  102  includes a housing assembly  104  comprising a base  104 A and a top  104 B, which when connected together serve to house various components of the device  102 . The housing assembly  104  may be operatively associated with a motor housing assembly  106  through interaction with a plenum cradle assembly  108 , comprising a top plenum cradle  108 A and bottom plenum cradle  108 B, as shown in  FIG. 1 . The motor housing assembly  106  can contain a vacuum motor  110  designed to power the vacuum cleaning operations of the device  102 . The motor  110  can be provided as an AC motor (e.g., 120 VAC) to power an impeller vane by direct drive to generate vacuum suction as needed by the device  102 . Overall, the various electrical components of the device  102 , including the motor  110 , can be powered by a power cord  112  adapted to be received into an electrical outlet, for example, of a home or businesses, or another suitable external power source. In addition to or in place of external power sources, the device  102  may also be powered through the use of various battery pack systems known in the art. In certain embodiments, the device  102  may be configured to accept and use input power from a variety of 110-120VAC /50-60 Hz external power sources. Alternately, the motor housing assembly  106  can be located within the housing assembly  104 . The housing assembly  104  and motor housing assemblies, as well as other portions of the device, can take different configurations, such as the embodiment sown in  FIGS. 14A-C , among others, without departing from the spirit of the invention. 
     It is envisioned that the device can be made in various configurations and sizes. For example, the device can be made in a hand-held embodiment and in various sizes for home or industrial use. Embodiments can be envisioned which accord use of various vacuum nozzle structures which incorporate the UV bulb assembly. 
     As shown in  FIG. 1 , a pole assembly  114  extends from the motor housing assembly  106  to a handle assembly  116  for the device  102 . The handle assembly  116  of the device  102  may include various indicators (e.g., LED lights) that communicate the current operational condition of the device  102  to a user. The handle assembly can further include various switches that can be used to power the motor  110  or motors on or off, for example, and/or to activate or maintain other functions of the device  102 , such as the UV bulb assembly, as described below. 
     The pole assembly  114  may be structured with multiple segments positioned in a telescoping configuration, to permit the pole assembly  114  to extend or contract in overall length. For example, the pole assembly  114  may be extended to an extended telescoping position (as shown in  FIG. 1 ) for use on cleaning media such as carpeting or other floor surfaces. Also, the pole assembly  114  may be contracted in overall length to a contracted telescoping position to make overall handling of the device  102  more convenient and compact for applying the device  102  to cleaning media such as mattresses or furniture, for example, or to make the device  102  more compact for convenient storage during periods of non-use. 
     As illustrated in  FIG. 4 , various embodiments of the pole assembly  114  may include a lower pole section  114 A connected in a telescoping configuration with an upper pole section  114 B. As shown, a proximal end of the lower pole section  114 A is connectable to the motor housing  106 , and a distal end of the upper pole section  114 B is connectable to the handle assembly  116 . To facilitate the telescoping action of the pole assembly  114 , the diameter of the lower pole section  114 A may be configured to be greater than the diameter of the upper pole section  114 B to facilitate receiving or sliding the upper pole section  114 B into the lower pole section  114 A, such as when the pole assembly  114  is in the contracted telescoping position. A connector collar  114 C including portions  114 D,  114 E may be structured to at least partially engage a distal end of the upper pole section  114 B and a distal end of the lower pole section  114 A. The portions  114 D,  114 E may be connected to form the connection collar  114 C by use of conventional fastening means such as screws  114 F- 114 I, for example, which secure the connection collar  114 C to the pole assembly  114 , as shown. 
     In various embodiments of the pole assembly  114 , a locking mechanism  114 J may be positioned within a slot  114 K of the connection collar  114 C. The locking mechanism  114 J may include a body segment  114 L having a locking spring  114 M connected at a first end of the body segment  114 L. In operation, the locking spring  114 M resiliently biases the first end of the body segment  114 L outwardly from the connector collar  114 C and promotes movement of a locking tab portion  114 N of the body segment  114 L inwardly toward the upper pole section  114 C. In the extended telescoping position, the locking tab portion  114 N may be received into a first slot  114 O formed in the upper pole section  114 C. In the contracted telescoping position, the locking tab portion  114 N may be received into a second slot  114 P formed in the upper pole section  114 B. The locking tab portion  114 N may be released from either of the slots  114 O,  114 P by depressing an area of the body segment  114 L of the locking mechanism  114 J adjacent to the locking spring  114 M thus counteracting the resilient bias of the spring  114 M. It can be seen that the resilient outward bias of the locking spring  114 M serves to promote receipt of the locking tab portion  114 N into the slots  114 O,  114 P, depending on whether an expanded or contracted telescoping position, respectively, is desired for use with the device  102 . 
     One or more wheels  118 ,  120  may be operatively associated with the base  104 A of the main housing assembly  104  to facilitate movement or travel of the device  102  across a cleaning medium. Also, a handle lock lever assembly  122  may be employed in the device  102  to permit locking or release of the angular movement of the collective arrangement of the handle assembly  116 , the pole assembly  114 , and the motor housing assembly  106  relative to the main housing assembly  104 . It can be appreciated that permitting this relative angular movement enables convenient travel of the device  102  on the wheels  118 ,  120  across a cleaning medium such as by locomotion of a user, for example, employing the device  102 . 
     In various embodiments, as shown in  FIG. 1 , a collection bin  124  may be removably received into a cavity within the main housing assembly  104  or elsewhere to receive organic or inorganic particles, substances, or infestation agents extracted from cleaning media through the base  104 A of the main housing assembly  104  during vacuum operation of the device  102 . A spring-released push button may be provided on the collection bin  124  to release a hinged bottom of the bin  124 , thereby allowing collected materials to be released from the bin  124 . The collection bin  124  may use a cone-shaped geometry to generate cyclonic action within the bin  124  that maximizes separation of collected material before air reaches a filter  125  at the back side of the collection bin. In certain embodiments, the collection function performed by the collection bin  124  can be instead achieved by a conventional bag-type arrangement, or another functionally equivalent device or mechanism that can be employed in the device  102  to collect debris, materials, and/or infestation agents extracted from various cleaning media by action of the device  102 . 
     Movement of the organic or inorganic particles, substances, or infestation agents extracted from cleaning media to the collection bin  124  may be further facilitated by one or more airways, such as defined by passageway members  126 ,  128 , as shown. The filter  125  may be positioned within a filter housing  130  and installed within the main housing assembly  104  to filter “dirty” air processed through the device  102  during a vacuum operation, for example. A replaceable, disposable filter  125  or a reusable filter may be used in conjunction with the collection bin  124  to capture debris or infestation agents extracted from cleaning media by operation of the device  102 . In certain embodiments, HEPA filtration may be used to maximize the capture of various infestation agents extracted from cleaning media. 
     In various embodiments, a beater bar  132  may be positioned within the main housing assembly  104  and configured to rotate during a beater bar operational mode of the device  102 . The beater bar  132  may be operatively associated with a beater bar motor  134 , such as through a belt drive  136 , to enable its rotation. The beater bar motor  134  may be a single-speed motor of AC or DC variety that powers the rotation of the beater bar  132  through a mechanical operative association with the belt drive  136 . Alternately, a single motor can be employed to operate both the beater bar and vacuuming functions of the device. It can be appreciated that the beater bar  132  can be configured to rotate with sufficient speed to effectively impact the cleaning medium on which the device  102  is employed. For example, the beater bar  132  and beater bar motor  134  can be selected or configured so that carpet fibers can be effectively agitated on both higher and lower knap carpeting. In other examples, the beater bar  132  can be configured for effective sweeping of hard floor surfaces, mattresses, and/or furniture. 
     In various operational modes of the device  102 , the rotating beater bar  132  may be structured to extract and carry infestation agents present within a cleaning medium to a surface of the medium and/or to within proximity of various portions of the base  104 A of the main housing assembly  104  that are in the proximity of the cleaning medium. The beater bar  132  may include one or more beaters  132 A,  132 B,  132 C extending therefrom that, during rotation of the beater bar  132 , can function to act upon a cleaning medium, such as to agitate or spread fibers in a carpet or mattress, for example. The beaters  132  can be of solid construction, such as of rubber or plastic strips, or can be made of a plurality of bristles. 
     In various embodiments, a light bulb assembly  142  may be positioned within the main housing assembly  104 . As described below in more detail, the light bulb assembly  142  may be structured to radiate UV light onto or into a variety of cleaning media upon which the device  102  may be employed. The UV light supplied by the light bulb assembly  142  may be configured to irradiate, sanitize, or otherwise disinfect a variety of infestation agents that may be present within a given cleaning medium. For example, the device  102  may use UV light radiated from the light bulb assembly  142  to sanitize dust mites living in the carpet flooring, mattresses, or furniture of a home or business. 
     In general, UV light wavelengths are considered less than about 400 nm and beyond the range of visible light. The UV portion of the light spectrum can be classified into three wavelength ranges: UVA (from 315 nm to 400 nm); UVB (from 280 nm to 315 nm); and, UVC (from 100 nm to 280 nm). In general, UV light with a wavelength shorter than about 300 nm is considered effective at killing micro-organisms including bacteria, viruses, and molds. In particular, research has shown that UVC light is optimal for killing micro-organisms. The UVC range of light wavelengths is commonly called the “germicidal” bandwidth, because light in this range can deactivate the DNA of microorganisms and destroy their ability to multiply. Specifically, UVC light causes damage to the nucleic acid of microorganisms by forming covalent bonds between certain adjacent bases in the DNA. The formation of such bonds prevents the DNA in the microorganism from being “unzipped” for replication, and the microorganism is unable to reproduce. When the microorganism tries to replicate, it is destroyed. 
     Research conducted in association with development of the invention has shown that dust mites often spend most of their time at or near the surface of cleaning media in which they are present, such as mattresses and carpeting, for example. It has also been discovered, however, that dust mite eggs and larvae may be at or near the surface, and/or deep within the cleaning media (e.g., buried in carpet fibers). The research has demonstrated that UVC light can be effective at disrupting the life cycle of microorganisms including dust mites, for example, if the UVC light is shined directly on the eggs and larvae of the microorganisms. As a result, various embodiments of the invention can be structured to achieve maximum irradiation within a cleaning medium (e.g., within carpet fibers). This irradiation can be achieved by placing the UV light source (e.g., light bulb) above or near protruding members that condition the cleaning medium to receive penetrating UVC light. It has been discovered that UVC light has the potential to break the life cycle of various microorganisms such as dust mites, for example, by killing the embryonic stage and thereby stopping the production of allergenic proteins in feces and exuviae. It was found that even a relatively small dose of UVC light had a fairly significant effect on dust mite reproduction, by affecting the rate of egg-laying and reproduction of the dust mites. 
     The effectiveness of UV light on infestation agents or microorganisms is directly related to the intensity of the light and exposure time. To be effective, the UVC light rays can be directed to strike a microorganism with sufficient intensity and exposure time to penetrate the microorganism and break down its DNA molecular bonds. It is important to understand that UV light acts on a cumulative basis. In other words, if the molecular bonds of a particular microorganism are not broken down on a first application of UV light emanating from the device  102 , subsequent applications of UVC light will continue to break down the DNA on a cumulative basis with the prior applications. The dosage of UVC light (in terms of millijoules per square centimeter or “mJ/cm 2 ”) is a product of light intensity (or irradiance) and exposure time. Intensity is measured in microwatts per square centimeter (μW/cm 2 ), and time is measured in seconds. In a given region irradiated with UVC light, for example, most microorganisms in the region can be eradicated with an efficiency of about four logs (that is, 99.99%) with a UVC dosage of about 40 mJ/cm 2 . For example, if it is assumed that the UVC light intensity applied to a particular surface area of a cleaning medium is 2 μW/cm 2 , and the exposure time is 20 seconds, then the UVC light dosage would be 40 mJ/cm 2 , thus eradicating or disinfecting about 99.99% of the microorganisms on the surface area. In numerous applications, UVC radiation of about 253.7 nm can be useful for eradication or disinfection of various kinds of microorganisms, although the invention is not limited to use at or near that range. In various embodiments, the disinfecting device may be configured to eradicate at least about 90%, or more preferably at least about 99% or 99.99%, of the infestation agents present within a cleaning medium during normal use. 
     Referring again to  FIGS. 1 and 2 , the light bulb assembly  142  may include a frame  142 A having a generally curved reflector  142 B attached thereto which is structured to receive and at least partially enclose or encase an ultraviolet light bulb  142 C therein. The reflector  142 B may be composed of a reflective material (e.g., highly polished aluminum) that can serve to re-direct or reflect UVC light emanating from the light bulb  142 C toward the cleaning medium. The reflective surfaces may be smooth or faceted, specular or semi-specular, or diffusing and may be made of any reflective materials. The light bulb  142 C may be, for example, a generally U-shaped, 35-watt, high-output, no-ozone bulb suitable for radiating light in the UVC wavelength range of light. Alternately, a single linear bulb or multiple linear or shaped bulbs can be employed. Further, a bulb-in-bar arrangement, as explained herein, can be used ion conjunction with other bulbs. The bulb  142 C may be powered by insertion into a socket  142 D which may be electrically connected to a ballast  144  or another power source. In certain embodiments, the ballast  144  may be a 120VAC, 800 mA ballast, for example. 
     It can be appreciated that the intensity of radiation emitted from a UV light source (e.g., the light bulb  142 C), and the associated disinfecting effectiveness of the radiation, are a function of the proximity of the UV light source to the cleaning medium. The inventors have discovered that, for certain applications and embodiments of the devices described herein, the light bulb  142 C may be positioned no more than about 2 inches from a surface of the cleaning medium, more preferably no more than about 1 inch from the surface of the cleaning medium, and most preferably no more than about 0.5 inches from the surface of the cleaning medium, to maximize the effectiveness of the devices in disinfecting infestation agents present within a cleaning medium. 
     It can further be appreciated that the dosage of the UV radiation is a function of the time of exposure of the cleaning medium to the radiation. To this end, it is a purpose of the invention to provide embodiments which provide for sufficient duration of exposure of the infestation agents to the UV radiation. As seen in  FIG. 2 , multiple UV bulbs can be employed, which when the device is in use, will approximately double the amount of time the UV light irradiates any given area of cleaning medium over a single linear bulb design at a given rate of speed. Alternately, a U-shaped bulb can be employed, which will approximately double the exposure time over a single linear bulb at a given rate of travel. The device can employ multiple linear and/or shaped bulbs. Alternate arrangements can be employed as well, such as at least one bulb in front of and at least one bulb behind the beater bar, as seen in  FIG. 5A . 
     The arrangement, shape and number of bulbs will effect the duration of exposure of the cleaning medium at a given rate of travel of the device. Obviously reaching a target dosage of 30-40 mJ/cm 2  is more easily achieved under normal use conditions if that dosage can be reached in 1-3 seconds of exposure. That is, a normal user is less likely to use the device slowly enough to expose the cleaning medium for a lengthy period of time, such as 20 seconds. The device is preferably designed such that at a normal rate of use, that is, at a normal or slow walking pace, any given area of cleaning medium will be exposed for a duration of time sufficient to eradicate 90% of infestation agents, or more preferably 99% or 99.99% of eradication. The arrangement of the bulb or bulbs can be designed to expose an area of cleaning medium, at a slow to normal walking pace, to at least one second of exposure to UV light and more preferably for about two seconds or more of exposure. The desired duration of exposure will vary depending on the intensity of the radiation as determined by the distance from the light source to the cleaning medium, the power of the light source and the effectiveness of reflectors. 
     A lens  147  may be included in the light bulb assembly  142  positioned in a lens frame  142 F, and this arrangement may serve to protect the light bulb  142 C from breakage and/or direct contact with surfaces or other objects. To further protect the light bulb  142 C from shock and vibration effects, an isolator  142 G or shock absorber or dampener can be employed. The shock dampener can be made of rubber or another suitable material and be positioned on one or more if the distal ends of the light bulb  142 C, as shown in  FIG. 2 . In certain embodiments, foam or rubber cushions and/or suspension supports may be positioned adjacent to the light bulb  142 C and/or around the socket  142 D to absorb forces or vibration arising from operation and use of the device  102 . 
     The lens  147  is preferably disposed between the light source or bulb  142 C and the cleaning medium. The lens resists direct human contact with the light bulb  142 C, which is advantageous because the presence of finger prints, for example, on the light bulb  142 C may hinder transmittance of UVC light during operation of the device  102 . In the event the light bulb  142 C breaks, for example, it can be seen that the lens  147  promotes containment of light bulb  142 C fragments within the assembly  142 . The lens  147  is made of a substantially translucent material. In certain embodiments, the lens  147  may be composed of a relatively thin (e.g., about 3 mm) fused silica or quartz glass, or a substance that allows greater than 80% transmittance of UV light therethrough. More preferably, the lens  147  allows greater than 90% transmittance of UV light, or 95% transmittance or higher. The thickness of the lens can vary, although typically the thinner the lens the better the transmittance. Accordingly, a thinner lens is preferable, in one embodiment a lens of no more then three mm is preferred. 
     Adjacent to the lens  147 , or directly below the lens  147 , at least one protruding member  143  extends from the device and into contact with the cleaning medium. Preferably the protruding members  143  extend from the lens frame  142 F or from the lens  143  itself. During operation of the device  102 , the protruding members  143  serve to act upon the cleaning medium (e.g., by contacting the medium and spreading open a section of carpet flooring or a mattress) to promote penetration of UV light into the cleaning medium. The protruding members  143  may also serve to prevent leakage reflection of UV light rays away from the interior of the light bulb assembly  142 . Although a single protruding member can be employed, a plurality is preferred. 
     The protruding members  143  can be arranged variously, such as seen in  FIGS. 2 ,  2 A-B and  5 . In  FIG. 2 , the protruding members are arranged adjacent the lens  147 , both in front of and behind the lens and UV light source  142 C. Alternately, as seen in  FIGS. 2A and 2B , the protruding members can extend across the lens and across the UV light source  142 C. The protruding members  143  can extend across the lens  147  longitudinally, as in  FIG. 2B , or diagonally or laterally, as seen in  FIG. 2A . Preferably, the protruding members are attached to the lens frame  142 F, as seen in  FIGS. 2 ,  2 A-B and  3 . Alternately, as seen in  FIG. 5 , the protruding members can extend directly from the lens itself. For example, the lens  147  can be manufactured to include protruding members  143  therefrom or such members may be attached to the lens by adhesives and the like. The protruding members  143  can be opaque, translucent or transparent and can be made of rubber, plastic or other materials. Alternately the members  143  can be made of a plurality of bristles. The members  143  can be flexible or inflexible, but should be stiff enough to effectively move carpet fibers. If the protruding members extend across the direct path of the UV light, it may be preferable that they transmit UV light through to the cleaning medium. 
     As seen in  FIG. 5 , the protruding members  143  at least partially fall in the direct path of UV light irradiated form the UV light source  142 C, as seen by the path of rays (as indicated by arrows). The protruding members  143  are designed to contact a carpet cleaning medium, pushing the fibers of the carpet apart to create space for the direct shining of UV light upon areas of the fibers that would not otherwise receive direct radiation. As the device  102  is moved back and forth over the carpet cleaning medium, the protruding members  143  act to open up the medium to direct UV light. In this manner, the deeper areas of the medium which may bear infestation agents, especially eggs, are subject to irradiation. In  FIG. 5 , the device  102  is seen moving right to left, opening up the carpet fibers as the protruding members contact and force apart the fibers. As the device is moved in the opposite direction, the protruding members will again create space between the fibers allowing UV light to reach into previously hidden portions of the cleaning medium. Since the effect of UV radiation on infestation agents is cumulative, the protruding members are designed to allow a greater combined duration of exposure as the device is moved back and forth across the cleaning medium. 
     The protruding members  143  may be stationary, as seen in  FIGS. 2 ,  2 A-B and  5 , or can be designed to move relative to the device  102 . For example, in an embodiment employing the bulb-in-bar assembly, as explained herein, the beaters of the beater bar serve as protruding members  143  since they fall in the path of the light source  142 C. In such a case, the protruding members are not stationary, but move independently with respect to the light source. 
     The lens frame  142 F can be removably or pivotally attached to the device housing, such as by latches  149  or other known mechanisms so that the lens frame can be moved away from the lens to facilitate cleaning of the lens. 
     In another embodiment of the device, the lens  147  is not supported above the surface of the cleaning medium. Rather, the lens is designed to contact the medium as the device is moved across the medium surface. In such a way, the lens is constantly wiped during use, thereby removing any dust that may otherwise adhere to the exterior of the lens  147 . Since UV light is absorbed so readily, dust build-up on the exterior of the lens will adversely effect the disinfecting capabilities of the device. Consequently, the lens may be cleaned between uses by the user or, in the embodiment just described, use of the device will also constitute a method for removing dust from the lens. 
     As shown schematically in  FIG. 5 , the light bulb  142 C may be positioned in an inner bulb chamber  145  of the light bulb assembly  142 . The bulb chamber  145  can be formed of various components but must provide for positioning of the bulb or bulbs  142 C therein. Radiant energy or light beams (depicted schematically by the representative arrows illustrated in  FIG. 5 ) emitted from the light bulb  142 C shine directly or indirectly from the light bulb  142 C onto and/or into a cleaning medium  146 . It can be seen that light beams incident on the reflector  142 B can be reflected back from the reflector  142 B toward the cleaning medium  146  to further enhance the effectiveness of the light bulb assembly  142  in disinfecting or sanitizing infestation agents residing within the cleaning medium  146 . 
     The inner bulb chamber  145  may be formed by the collective arrangement of chamber walls  151  and the lens  147  to create an ambient environment around the light bulb  142 C, as seen in  FIG. 5 . Alternatively, the chamber walls  151  can be comprised of or incorporate a portion or the entirety of the reflector  142 B. Such an arrangement is seen in  FIG. 7 . Preferably, the bulb chamber is substantially dust-tight. That is, the bulb chamber remains substantially free of dust and other particles during use. To this end, various seals and gaskets can be employed to better seal the chamber. Since about 90% of all particles are smaller than 0.3 microns, the chamber is preferably designed to substantially prevent infiltration by particles of that size or even smaller. It is important to prevent dust in the chamber since such dust will tend to collect on the exterior of the UV light bulb  142 C and act to absorb the emitted UV light, preventing the UV light from reaching the cleaning medium. The chamber can further be airtight. The chamber, in the embodiment of  FIG. 5 , is defined primarily by the chamber walls  151  and lens  147 . Consequently, the walls and lens preferably are sealed against substantial dust intrusion. In this embodiment, the reflector  142 B need not create a separate sealed chamber, although it is depicted as doing so, as it is entirely enclosed within the bulb chamber created by the walls  151  and lens  147 . In another embodiment, as seen in  FIG. 7 , wherein the reflector  142 B comprises a bulb chamber wall, the reflector and lens preferably create a chamber substantially or wholly sealed against dust particles. 
     In one example of an experiment conducted in association with development of the invention, conditions used in developing the light bulb  142 C specifications were as follows: a desired dosage of 40 mJ/cm 2  was selected in order to achieve about 99.99% eradication of most microorganisms; the device  102  was moved at a relatively slow walking pace across a carpet cleaning medium, exposing any particular area of the carpet to approximately two seconds of UVC light; the light bulb  142 C was positioned about 0.5 inches from the surface of the carpet; the beater bar  132  was employed to optimize bringing microorganisms to the surface of the carpet for maximum exposure to the UVC light; and, the reflector  142 B was employed. With these experimental conditions, it was determined that a generally U-shaped, 42-watt, 8.7 inch light bulb  142 C generated approximately 12.6 μW/cm 2  of UVC irradiance. With the addition of the polished, curved aluminum reflector  142 B behind the light bulb  142 C in the light bulb assembly  142 , the UVC irradiance generated was in the range of approximately 20 μW/cm 2 . With one second of exposure, it was discovered that this configuration for the light bulb assembly  142  generated approximately 20 mJ/cm 2  of a UVC light dosage; with two seconds of exposure, the configuration generated approximately 40 mJ/cm 2  of UVC light dosage to achieve the desired four logs (i.e., 99.99%) eradication of microorganisms. A specific example involving the influenza virus helps to illustrate the dosage needed: to eradicate influenza virus in the carpeting with the above experimental conditions, a UVC light dosage of 6.6 μW/cm 2  would be needed. This UVC light dosage could be achieved in the first 0.33 seconds of passing the UVC light bulb  142 C over the influenza virus in the carpet. The exposure time of any given area of cleaning medium will, of course, be greater than that achieved on a single pass of the device since most users will not simply walk across the area but will rather push and pull the device over the same area multiple times. 
     In various embodiments of the invention, it may be desirable to employ structures or mechanisms that facilitate heat dissipation within or in the immediate vicinity of the light bulb assembly  142 , such as to control the ambient air temperature in the bulb chamber  145 . With reference to  FIG. 6 , solid arrows  152  represent rotation of the beater bar  132  as it acts upon a cleaning medium  156  during travel of the device  102  (represented schematically by arrow  158 ) during operation. In association with operation of the device  102 , as shown schematically by representative arrows  154 , air flow can be facilitated by negative pressure generated by action of the vacuum motor  110 . The air flows from the beater bar  132  through a collection bin airway  160 , through the collection bin  124 , and then through a vacuum motor airway  162  leading to the vacuum motor  110 . 
     In various embodiments, heat transfer may be effected by structuring the chamber walls  151  for exposure to cooling air flow through the device  102 , such as air flow generated during a vacuum operation. It can be appreciated that operation of the light bulb  142 C within the inner bulb chamber  145  of the light bulb assembly  142  can generate heat in the ambient environment or air around the light bulb  142 C. The temperature of the ambient environment within the bulb chamber  145  can impact performance or effectiveness of the light bulb  142 C. Thus, in certain embodiments, it is desirable to structure the chamber walls  151  from conductive material or materials that conduct heat from the inner bulb chamber  145  and into contact with the airflow streaming through the device  102 , such as during a vacuum operation. Examples of suitable materials that may be used for the chamber walls include aluminum, aluminum alloys, or other metals that can adequately conduct heat away from the inner bulb chamber  145 . In certain embodiments, where the chamber walls  151  are coextensive with the reflector  142 B, the reflector  142 B is comprised of material that is both a reflective and heat conductive material. 
     In certain embodiments, and with particular reference to  FIG. 7 , one or more airflow holes, such as airflow hole  182 , may be formed in the chamber walls  151  adjacent to an airflow stream. The pressure differential between the ambient air inside the inner bulb chamber  145  of the light bulb assembly  142  and the airflow stream  154  external to the inner bulb chamber  145  may be configured to draw air, and heat recumbent in the air, from the inner bulb chamber  145  into the airflow stream  154 . In various embodiments, one or more airflow inlet holes may be formed generally adjacent to the isolator  142 G, or one or more airflow outlet holes may be formed in the chamber walls  151  or reflector  142 B adjacent to the airflow stream. 
     In various embodiments, as shown in  FIGS. 5 and 7 , a fin assembly  190  including one or more fins may be connected to the reflector  142 B to further increase the capability to transfer heat from the inner bulb chamber  145  to the airflow stream. As seen in  FIG. 7 , the fin assembly  190  is mounted or formed directly on the reflector  142 B, since the reflector forms a chamber wall. Alternatively, where the chamber wall  151  does not include the reflector  142 B, as seen in  FIG. 5 , the fin assembly  190  is preferably formed or mounted on the chamber wall  151 . Also seen in  FIG. 5  are fin assemblies  190  on the reflector  142 B. 
     In an arrangement which includes airflow holes in the chamber  145 , it is preferable to use an air filter  183  to filter the airflow entering the chamber. The air filter  183  preferably eliminates dust and other airborne particles from reaching the interior of the chamber. As explained above, the chamber is preferably dust tight. Consequently, the air filter  183  is preferably effective to eliminate most particles of 0.3 microns or even smaller. 
     It can be appreciated that such air flow engineering can be beneficial for thermodynamically transferring heat away from the inner bulb chamber  145  to enhance the effectiveness of the radiant energy supplied by the light bulb  142 C. In certain embodiments of the light bulb  142 C, for example, it has been discovered that the effectiveness of UVC light radiance is reduced when the ambient air temperature around the bulb  142 C rises above about 110 degrees Fahrenheit and higher. The device is preferably designed, therefore, with a heat dissipation system effective to maintain the bulb chamber at 110 degrees Fahrenheit or lower. Further, the device can employ a temperature sensor and associated indicator light or switch-off to alert the user to the elevated temperature or switch off the device to allow cooling. 
     With reference to  FIG. 8 , in various embodiments, the light bulb  202  and the beater bar  204  may be integrated into a single bulb-in-bar assembly  206  for use in a disinfecting device. As shown, the light bulb  202  may be at least partially encased by a skeleton frame  204  including first and second skeleton portions  204 A,  204 B which collectively form the beater bar  204 . Openings  204 C- 204 F may be formed in the beater bar portions  204 A,  204 B permit UV light radiated from the light bulb  202  to escape from the bulb-in-bar assembly  206 . It can be appreciated that, in certain embodiments, the skeleton portions  204 A,  204 B of the skeleton frame beater bar  154  may be replaced by a single-piece skeleton frame structured to at least partially encase the light bulb  202  therein. As shown, one or more beaters  204 G,  204 H formed on the beater bar portions  204 A,  204 B function to condition or beat a cleaning medium, such as the fibers of a carpet floor, to bring infestation agents towards or to the surface of the cleaning medium. In the bulb-in-bar embodiment, the beaters also can function as protruding members, as explained above, extending into the cleaning medium and separating carpet fibers for direct exposure to UV light emanating from the UV bulb. The beater bar portions  204 A,  204 B may be secured by the use of one or more C-clamps  208 ,  210 ,  212  to hold the beater bar  204  together and to maintain the light bulb  202  securely within the bulb-in-bar assembly  206 . In addition, one or more rubber O-rings  214 ,  216 ,  218 ,  220  may be employed to protect the light bulb  202  from shock and vibration. In certain embodiments, a protective sleeve or lens  222  comprised of a transparent material, such as quartz glass or fused silicon, may be positioned underneath the beater bar portions  204 A,  204 B, and outside of the light bulb  202  to at least partially encase and protect the light bulb  202  from contact with objects, materials, or infestation agents. The bulb-in-bar assembly  206  may be positioned within a frame  224 , including first and second frame portions  224 A,  224 B as shown, which facilitates rotation of the bulb-in-bar assembly  206  during operation of the device  102 . It can be appreciated that the bulb-in-bar assembly  206  can serve to maximize penetration of UV light irradiation into a cleaning medium. 
     As with other embodiments of the device, it is preferable that the bulb chamber in the bulb-in-bar assembly be substantially or wholly dust tight as described above. Consequently, the bulb-in-bar assembly will employ gaskets and seals as needed or desired. 
     The schematic of  FIG. 9  illustrates that, for certain embodiments of a modified device  102 , the bulb-in-bar assembly  206  may be installed for operation. In view of the light bulb  202  being included within the beater bar skeleton frame  204 , it can be seen that a separate light bulb assembly  142 , as described above, is not required. The bulb-in-bar assembly can be used in conjunction with other UV bulbs, however. Otherwise, the various features of the device  102  can be readily structured for applicability to the embodiment of the device as illustrated in  FIG. 9 . 
     With reference to  FIG. 10 , a main power switch  232  and a beater bar on/off switch  234  may be located on the handle assembly  116  of the device  102  or elsewhere on the device  102 , such as on the main housing assembly  104 , for example. The main power switch  232  enables the device  102  to receive power from an external power source or battery. The beater bar on/off switch  234  enables rotation of the beater bar  132  in various operational modes of the device  102 . In addition, a safety switch  236  may be positioned on the top, bottom, or other user-accessible portion of the handle assembly  116  that can be configured such that the safety switch  236  must be depressed or activated during operation of the device  102  to permit the light bulb  142 C to be activated. Likewise, when not depressed or activated, the safety switch  236  can be configured to either deactivate the light bulb  142 C, or otherwise not permit the light bulb  142 C to be activated until the safety switch  236  is depressed. One or more indicators  238  may be provided on the handle assembly  116  and/or the main housing assembly  104 , for example, to communicate activation of the light bulb  142 C to a user of the device  102 . For example, the indicator  238  may be configured to be lit when UVC light is being radiated from the light bulb  142 C to indicate to a user that disinfection of the cleaning medium is underway. It can be appreciated that positioning the safety switch  236  on the handle assembly  116  in certain embodiments promotes keeping the user at a minimum distance from the radiance of the light bulb  142 C when the light bulb  142 C is activated during operation of the device  102 . 
     The safety switch  236  is preferably a dead man&#39;s switch or deadman device. That is, the switch is designed to shut of or deactivate the UV light source in case the user becomes incapacitated or otherwise ceases activation of the deadman switch. This fail safe mechanism is designed to prevent the user from direct exposure to the UV light. The safety switch can be of any type known in the industry, can employ a trip cord, be a simple trigger or depression switch, or be of other design. 
     With reference to  FIGS. 11 and 12 , one or more cleaning medium contact switch assemblies  250 ,  252  may be positioned in operative association with the base  104 A of the main housing assembly  104 . Each of the cleaning medium contact switch assemblies  250 ,  252  includes a floor or cleaning medium contact portion  250 A,  252 A (respectively), connected to an electrical switch portion  250 B,  252 B (respectively), through a mounting plate  250 C,  252 C (respectively), as shown. During operation of the device  102 , the weight of the device  102  is sufficient to activate the push button switches  250 D,  252 D and allow activation of the UV light source. Preferably, the switch assemblies also function to communicate an electrical signal that lights bulb  142 C to alert the user that the switches are depressed and the UV light is active. In various embodiments, each contact portion  250 A,  252 A may be covered by a generally rounded, durable plastic material structured to minimize friction with a cleaning medium when the device  102  travels across the cleaning medium. In certain embodiments, it can be appreciated that the cleaning medium contact switch assemblies  250 ,  252  prevent activation of or deactivate the light bulb  142 C when the device  102  is lifted or tilted away from the cleaning medium, thus releasing one or both of the push button switches  250 D,  252 D. This prevention of activation or deactivation of the light bulb  142 C may be configured to occur even if the safety switch  236  is already activated in a mode (e.g., in a depressed state) that would normally permit or enable activation of the light bulb  142 C. 
     Other safety switches may be employed as are known in the art. Such switches include various dead-man switches, whether located on the handle assembly or elsewhere. Other contact switches or proximity switches may be employed, such as an optical or laser switch operable to cut off power to the UV bulb if a cleaning surface is not within a prescribed distance. A motion sensor and safety switch which operates to shut off the UV bulb when the device is stationary can be used, whether the switch is keyed to motion of the device, turning of the device wheels or otherwise. Similarly, other motion sensors and switches or gravity switches may be employed. 
     In various embodiments, it can be appreciated that multiple safety mechanism can be employed. For example, the cleaning medium contact switch assemblies  250 ,  252  may be configured to cooperate in conjunction with the deadman safety switch  236 , and/or in association with other safety features such as the airflow engineering embodiments described above, to provide a multiple and integrated safety system for the device  102 . For example, the cleaning medium contact switch assemblies  250 ,  252  and the safety switch  236  may be electrically connected in series such that if one or both switches are opened the light bulb  142 C is electrically disconnected from its power source and deactivated. The cleaning medium contact switch assemblies  250 ,  252  and the safety switch  236  may be further electrically configured upon deactivation to only turn off the light bulb  142 C, and not otherwise disable other operational modes of the device  102  (e.g., vacuum cleaning action or rotation of the beater bar  132 ). 
     In various embodiments, with reference to  FIG. 13 , one or more optical switches  302 ,  304  may be located in the base  104 A of the main housing assembly  104  and/or in the light bulb assembly  142 . As shown, the optical switches  302 ,  304  may be configured to determine when a surface of the base  104 A of the device  102  is more than a predetermined distance from a surface of the cleaning medium. For example, the optical switches  302 ,  304  may be configured to deactivate the light bulb  142 C when a predetermined detected distance between the optical switches  302 ,  304  and the cleaning medium is met or exceeded. In alternative embodiments, one or more mercury switches and/or one or more gravity switches may be employed in the device  102  to detect excessive tilt, slope, or other lifting of the device  102  with respect to the cleaning medium and to deactivate the light bulb  142 C in accordance with the detected tilted or lifted condition. In various embodiments, the optical switches  302 ,  304  may work in conjunction with the safety switch  236  and the cleaning medium contact switch assemblies  250 ,  252 , such that if any one or more of the optical switches  302 ,  304 , the safety switch  236 , or the cleaning medium contact switch assemblies  250 ,  252  is/are deactivated, then the light bulb  142 C can be deactivated or not permitted to activate. As those skilled in the art will appreciate, this arrangement may be achieved, for example, by electrically connecting the safety switch  236 , the cleaning medium contact switch assemblies  250 ,  252 , and the optical switches  302 ,  304  in series in the device  102 . 
       FIGS. 14A-C  present front, side and top views of an embodiment of the invention. The device  102  can employ various arrangements of the features described above, including a safety switch  236 , handle assembly  116 , housing  104 , light assembly  142  and cleaning assembly  132 . Those of skill in the art will recognize that the device  102  may take various forms such as are common in cleaning devices. 
     In general, embodiments of the device  102  described herein can be structured to operate in various modes: such as vacuum only, which can be useful for substantially solid or substantially non-compressible cleaning media such as the surface of a hardwood floor, for example; or, vacuum with accompanying beater bar  132  rotation for various types of surfaces or floor coverings, such as carpeting or mattresses. In addition, the light bulb  142 C may be on or off in either of these operational modes, radiating or not radiating UV light into the cleaning medium as desired during use of the device  102 . In various embodiments, the device  102  may be configured for use primarily to perform disinfecting operations in association with UV light or UVC light radiated from the light bulb  142 C. For example, such disinfecting operations may be performed with the device  102  as described above, with or without an accompanying vacuum cleaning operation capability, and/or with or without activation of the beater bar  132  or bulb-in-bar assembly  206  embodiments described herein. 
     It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, other elements. Those of ordinary skill in the art will recognize, however, that these and other elements may be desirable. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. It should be appreciated that the figures are presented for illustrative purposes and not as construction drawings. Omitted details and modifications or alternative embodiments are within the purview of persons of ordinary skill in the art. 
     It can be appreciated that, in certain aspects of the present invention, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to provide an element or structure or to perform a given function or functions. Except where such substitution would not be operative to practice certain embodiments of the present invention, such substitution is considered within the scope of the present invention. 
     The physical composition of various structural and functional components described herein may be comprised of different kinds of suitable materials. Examples of suitable materials that may be employed include, without limitation, polypropylene, polycarbonate, ABS plastic, polyethylene (e.g., HDPE), various elastomeric materials, and polytetrafluoroethylene (“PTFE”). 
     The examples presented herein are intended to illustrate potential and specific implementations of the present invention. It can be appreciated that the examples are intended primarily for purposes of illustration of the invention for those skilled in the art. The diagrams depicted herein are provided by way of example. There may be variations to these diagrams or the operations described herein without departing from the spirit of the invention. For instance, in certain cases, method steps or operations may be performed in differing order, or operations may be added, deleted or modified. 
     Furthermore, whereas particular embodiments of the invention have been described herein for the purpose of illustrating the invention and not for the purpose of limiting the same, it will be appreciated by those of ordinary skill in the art that numerous variations of the details, materials and arrangement of elements, steps, structures, and/or parts may be made within the principle and scope of the invention without departing from the invention as described in the following claims.