Abstract:
A sterilizer and storage container for kitchen tools, knives and cutting boards which sterilizes such items using ultraviolet light in the UV-C range. The sterilizer features a housing which encloses a receptacle made of a material or structure “transparent” to UV radiation for enclosing items to be sterilized, means for lifting and lowering utensils in said receptacle for ease of filling and emptying said receptacle, a source of UV light, a cover to seal the housing and prevent the leakage of UV light and a starter button to activate the UV light source. When the starter button is activated, UV light is directed through the receptacle and onto the items to be sterilized. The UV light destroys microorganisms on the surfaces of the items to be sterilized. The items are removed from the device in a sterilized state.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention is generally directed to a novel device for sterilizing knives, kitchen tools and cutting boards which can come into contact with, and harbor, harmful microorganisms, including bacteria and viruses. The invention provides a safe, fast and convenient way to disinfect and store such items. The device permits exposure of items placed therein to ultraviolet light, and provides a convenient storage device for the items.  
       BACKGROUND OF THE INVENTION  
       [0002]     Kitchens and other food preparation areas can have high levels of dangerous microorganisms, including bacteria, which thrive in warm, dark, moist environments. Kitchen items, including knives, tools and cutting boards, which contact meat, soft cheeses and other foods which harbor such microorganisms can spread such germs from one food to another, or from one tool to another. Ultimately, such microorganisms can be ingested in foods and cause serious illness, such as salmonella or  e. coli  infection. Vigilant cleaning with sufficiently hot water and soap and careful food preparation practices can minimize the risk. However, inconsistent cleaning habits, incorrect water temperature and lax food preparation practices can contribute to the growth of harmful microorganisms in the kitchen. Moreover, simple cleaning in soap and water is sometimes insufficient to kill all microorganisms on a given surface. Traditional cleaning with water also may be ineffective for items which cannot be completely submerged, such as wood, and items which can trap microorganisms in small spaces, such as knife handles. Heat, as from steam or microwaving, is undesirable as it may damage softer plastics, require cool-down time before use, or burn the user. Metal parts such as screws, handles and utensil parts make microwave activated sterilization impossible. Moreover, after such items are cleaned, they may come into contact with contaminated items, such as in a storage bin or drawer. Further, because such items contact food, it is important that they do not maintain any chemical residue from cleaning solutions.  
         [0003]     Thus, it is important to provide a system for disinfecting kitchen equipment, such as knives, tools and cutting boards, which can come into contact with, and harbor, harmful microorganisms. Moreover, it is important to insure thorough and complete sterilizing of such items. It also is desirable to provide a storage container for such equipment to insure that after sterilizing, such equipment does not come into contact with other equipment which may harbor dangerous microorganisms.  
         [0004]     The present invention addresses the need for a device for disinfecting kitchen equipment, such as knives, tools and cutting boards and provides a compact, attractive counter-top sterilizer which can accommodate a variety of kitchen equipment and which also provides an attractive and convenient storage container for such equipment.  
         [0005]     The present invention attains each of these goals through the use of a compact and convenient sterilizer and storage unit which uses ultraviolet, or “UV” light. UV light is invisible radiation having a wavelength of between 100 to 320 nm. The most effective range for sterilization is within 200 nm to 290 nm, designated the UV-C band, with a bandwidth between 250 nm and 260 nm being optimal. At this wavelength, such light is capable of inactivating and destroying a variety of bacteria, viruses, mold and other microorganisms. When UV-C light hits a microorganism, the light is absorbed by the microorganism, which is destroyed. Because the items are “sterilized” by light, they are not wet by, or submerged in, water, soap or chemicals. Thus, no drying or extreme heat is required, and no potentially harmful chemicals or soaps are left behind on the item. Even items that are not suitable to be washed in water, such as wood, can be sterilized with UV light.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention is directed to a novel device which comprises a housing, made of material suitable to contain UV radiation, which housing encloses a basket or receptacle made of a material or structure “transparent” to UV radiation, through which UV light may be transmitted for enclosing items to be sterilized, a knife block to receive knives to be sterilized, a source of UV light, reflective material to insure exposure of all surfaces to UV light and a door to seal the housing and prevent the leakage of UV light. When the system is activated, the UV light is directed through the receptacle and into the enclosure onto the items to be sterilized, insuring that UV light hits all surfaces of each piece of equipment to be sterilized. Internal surfaces of the device are coated with reflective material to insure exposure of all surfaces of knives, tools and cutting boards to UV light. The UV light destroys microorganisms on the surfaces of the equipment to be sterilized, but does not remain in or on the equipment.  
         [0007]     The equipment is removed from the device in a sterilized state. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  shows a front view of an embodiment of the invention.  
         [0009]      FIG. 2  shows a front view of the invention opened to show equipment therein.  
         [0010]      FIG. 3  shows a front view of the invention opened to show equipment therein.  
         [0011]      FIG. 4  shows an exploded view of an embodiment of the invention.  
         [0012]      FIG. 5  shows a longitudinal cross-sectional view of the embodiment of  FIG. 9  taken approximately along the line A-A of  FIG. 9 .  
         [0013]      FIG. 6  shows a top view of an embodiment of the invention.  
         [0014]      FIG. 7  shows a bottom view of an embodiment of the invention.  
         [0015]      FIG. 8  shows a side view of an embodiment of the invention.  
         [0016]      FIG. 9  shows a rear view of an embodiment of the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     Reference will now be made in detail to the preferred embodiments of the invention, examples of which are also provided in the following description. Exemplary embodiments of this invention are described in some detail, although it will be apparent to those skilled in the relevant art that some features that are not particularly important to an understanding of the invention may not be shown for the sake of clarity.  
         [0018]     The present invention is directed to a knife and kitchen tool sterilizer and holder. The housing of the sterilizer is constructed of material that is impervious to UV-C radiation, such as plastic, and contains knife holders for holding knives. The housing is sealed by a door, which provides access to inside the housing. The housing comprises a holder for placing articles to be sterilized, knife holders and a slot for a cutting board, a UV-C light source, a power source, and means for reflecting the UV-C light source such that all surfaces of all items placed therein are exposed to UV-C light.  
         [0019]      FIG. 1  is a front view of the sterilizer  10  in a closed position. Support  12  enables sterilizer  10  to stand in a semi-upright position. As shown in  FIG. 8  in a preferred embodiment, bottom  22  of sterilizer  10  is angled to enable sterilizer  10  to stand and tilt at an angle which is convenient for use. In one embodiment, the plane created by cover  14  in a closed position is maintained at an angle of 60 degrees from the surface on which sterilizer  10  is placed, for ease of use. Cover  14  enables the unit to be closed when it is activated and in a sterilization cycle or when items therein are being stored. UV activation switch  16  activates the UV-C light source located within the sterilizer and begins the sterilization cycle when depressed.  
         [0020]     Housing  11  comprises two vertical shells and is made of a material that is impervious to UV-C radiation. In one embodiment housing  11  is formulated from plastic. In another embodiment, as shown in  FIG. 2 , housing  11  is substantially rectangular in shape, with a rectangular protrusion  13  in the front of housing  11  to accommodate tool holder  27  (partially visible). Knife slots  18  are located in knife holders  20  and enable knives to be stored and sterilized in sterilizer  10 . In one embodiment, knife slots  18  are angled such that each knife is maintained at about a 40 degree angle from the horizontal plane created by the surface on which the sterilizer is placed to maximize exposure to UV light within sterilizer  10 . Knife holders  20  are fabricated from rigid material, such as plastic with a wood or plastic veneer to maintain the required angle. As shown in  FIG. 6 , cover  14  is shaped to close over sterilizer  10  in a manner which does not interfere with access to knife holders  20 . Hinge  23  of cover  14  enables cover  14  to open and rotate about 270 degrees back behind sterilizer  10  in an open position. As seen in  FIG. 2 , board slot  25  accommodates cutting board  26  for sterilization and storage. In one embodiment, shown in  FIG. 2 , tool holder  27  is positioned inside a recess defined by board slot  25 , knife holders  20  and protrusion  13  of housing  11 .  
         [0021]     As seen in  FIG. 3 , in one embodiment, sterilizer  10  accommodates knives  28  and tools  30  as well as cutting board  26  (not visible) for sterilization or storage.  
         [0022]     As shown in  FIG. 4 , which is an exploded view of sterilizer  10  showing the main components, housing  11  comprises front shell  31  and back shell  32 . Back shell  32  contains back protrusion  46  which houses electrical ballast  35 , starter  36 , sockets  39 , reflectors  41  and UV-C light source  38 . Back shell  32  also contains vents  48  to prevent electrical components housed in back protrusion  46  from becoming overheated. Front shell  31  comprises holes  50  (one not visible) which receive the arms of support  12 . Tool holder  27  comprises apertures  51  which enable UV-C light to pass through tool holder  27  and contact items therein. Tool holder  27  comprises three partial holder walls  19 . In one embodiment, apertures  51  are symmetrically spaced throughout walls  19  and are of uniform size.  
         [0023]     Tool holder  27  is made from material which is durable and not easily cut by sharp tools. In one embodiment, tool holder  27  is made of plastic mesh. The sides of tool holder  27  comprise ridges  52  on either side, each of which further comprises attachment tab  53  and screw hole  54 . Tool lever rod  45  is attached to tool cage lever  44  via fastener  47 . Tool floor  55  comprises a flat plate  56  rigidly fastened using standard techniques, such as welding, to a semicircular hinge  57 . In one embodiment, flat plate  56  and semi-circular hinge  57  are made of an integral piece of molded metal or plastic. Knife holders  20  are seated into collar  58 . In a preferred embodiment, collar  58  is fabricated from metal or plastic. In another embodiment, collar  58  contains a rubber sealing ring (not visible) around its inside rim  59  to provide a secure seal when sterilizer  10  is closed and to prevent leakage of UV-C rays.  
         [0024]     In assembly, as shown in  FIG. 1 , cover  14  is movably fitted into collar  58  and secured by a fastener, such as a clip, to form cover assembly  81  as shown in  FIG. 6 . As shown in  FIG. 4 , springs  21  are loaded into hinge  23 . Hinge caps  29  are then placed onto hinge  23  such that springs  21  exert outward tension on hinge caps  29  when the outward edges of hinge caps  29  are flush with the outside edges of hinge  23 . Hinge  23 , located on cover  14  is then seated between hinge caps  29  on rim  59 . The tension created by springs  21  inside hinge  23  movably secures cover  14  to rim  59  such that cover  14  can move in an arc of about 270 degrees around hinge  23 . While the arc may be decreased, an arc of about 270 degrees allows for ease of filling and emptying of tool holder  27  and removal and replacement of cutting board  26 . Activator  60  is electrically connected to activation switch  16  and is fastened into notch  61  on rim  59  via fastener  62 . Activation switch  16  is seated into notch  63  and rigidly attached thereto using standard techniques, such as soldering. Ballast  35  is fastened to ballast holder  36  using fasteners such as screws. Starter  36  is seated into starter holder  37  and fastened thereto using standard fasteners such as screws. UV-C light source  38  is fastened into sockets  39 .  
         [0025]     In a preferred embodiment, UV-C light source  38  is cylindrical type G6T5, has a wattage of 6, a base diameter of 15 mm, lamp diameter of 15 mm, is 9 inches in length, has a two 2-pin ceramic bases and is constructed of hard glass quartz. Effective sources of UV-C light are low pressure mercury discharge lamps. A preferred lamp is manufactured by Osram Sylvania, Inc. Another is manufactured by Royal Philips Electronics. Intensity at  1  meter using a type G6T5 bulb 16.7 uW/cm 2  and 173 uW/cm 2  In a preferred embodiment, starting voltage of UV-C lamp  50  is 120 VAC @ 60 HZ, operational voltage is 120 VAC @ 60 HZ, UV output is 253.7 nm @ 100 hrs. The average life of a G6T5-type lamp is 6,000 hours.  
         [0026]     Activator  60  is electrically connected to starter  36 . When pressed, activator  60  transmits an electrical signal to starter  36  which in turn activates UV-C light source  38 . UV-C light source  38  is electrically attached to ballast  35 , which provides resistance to stabilize current in the circuit created when sterilizer  10  is attached to a power source via power cord  69 . In a preferred embodiment, ballast  35  is operational with 100/200 VAC at 50/60 HZ.  
         [0027]     Tool holder  27  is attached to front shell  31  by standard fasteners, such as screws, which are placed through attachment tab  53  and screwed into holes  72  on the inside sides of front shell  31 . Tool lever rod  45  is placed through hole  74  of back shell  32  and through hole  76  in rod  78  of tool lifter  80 , such that a portion of tool lever rod  45  protrudes from the outside of back shell  32 . Tool cage lever is attached to the protruding portion of tool lever rod  45  via fastener  42 . Screw ends  81  of support  12  are placed through front shell  31  and secured by screw  42 , as shown in  FIG. 5 .  
         [0028]     Front shell  31  is then engaged with back shell  32  in a vertical plane such that back shell  32  and front shell  31  form housing  11  and enclose tool holder  27 . Front shell  31  and back shell  32  are fastened together using standard fasteners, such as screws. As seen in  FIG. 7 , bottom  22  is fastened to the bottom edge of back shell  32  and front shell  31  using bottom fasteners  82 . In one embodiment, bottom  22  may be covered in a fabric, such as felt, to prevent bottom  22  from scratching surfaces on which sterilizer  10  is placed.  
         [0029]     As seen in  FIG. 4 , cover assembly  81  is placed over and into tab  65  such that bar  67  on rim  59  engages lips  64  (partially visible) on tab  65 . Rim  59  can also be rigidly attached to tab  65  using standard fasteners, such as screws.  
         [0030]     All internal surfaces of back shell  32 , front shell  31 , tool floor  55  and cover assembly  81  are coated with UV-C material by vacuum coating or electro-coating or are made of UV-C reflective material, such as polished aluminum or stainless steel, to increase UV-C reflectivity when sterilizer  10  is closed and undergoing a sterilization cycle.  
         [0031]     In operation, sterilizer  10  is positioned to be resting on support  12  as seen in  FIG. 1 , such that cover  14  can be easily accessed. Cover  14  is opened and rotated about 270 degrees to rest on the back of back shell  32 , as seen in  FIG. 3 . As further seen in  FIG. 3 , knives  28  are placed into knife slots  18  in knife holders  20  such that the blades of the knives  28  are positioned on the sides of tool holder  27  and maintained at about a 40 degree angle from the horizontal plane created by the surface on which sterilizer  10  is placed. For ease of loading, tool lever  44  is rotated such that tool floor  55  is in a raised position and substantially perpendicular to front shell  31  and back shell  32 . Kitchen tools  30  are arranged in tool holder  27  such that they rest against tool floor  55 . As seen in  FIG. 2 , cutting board  26  is lowered into board slot  25 . Cutting board  26  is pushed down into board slot  25  such that the topmost edge of cutting board  26  is substantially flush with the top edge of back shell  31 . Tool lever  44  is then rotated such that tool floor  55  lowers, in turn lowering tools  30  into sterilizer  10  such that the tops of the tools  30  are substantially flush with the top edge of back shell  31 . Cover  14  is rotated forward toward front shell  31  and pressed down onto front shell  31  to form a seal, as shown in  FIG. 1 .  
         [0032]     Sterilizer  10  may be utilized in this manner as a storage unit for knives  28 , tools  30  and cutting board  26 . Such storage maintains these items in a clean, safe and convenient manner.  
         [0033]     If it is desired to sterilize such items, cover  14  is closed fully then the activation switch  16  is depressed, completing the electrical circuit inside sterilizer  10  and causing UV-C light source  38  to be activated. UV-C light source  38  emits UV-C radiation, which is directed through apertures  51  and onto the surfaces of knives  28 , tools  30  and cutting board  26 . UV-C emissions also are reflected off the coated surfaces of back shell  32 , front shell  31 , tool floor  55  and cover assembly  81  randomly onto the surfaces of knives  28 , tools  30  and cutting board  26 . As the organic, or carbon based microorganisms on the surfaces of such items are exposed to the UV-C light, the molecular bonds in such microorganisms are broken, causing genetic damage and preventing such organisms from reproducing, rendering them harmless. The ability of UV-C light to disable such microorganisms in this manner is directly related to intensity of UV-C light and exposure time. In a preferred embodiment, activation switch  16  is attached to a timer which enables the sterilizing cycle to proceed for a pre-set period of time. After the time period ends, UV-C light source  38  ceases emitting light. A sterilizing cycle of fifteen minutes has been found to be sufficient to insure sterilizing of six tools, a cutting board and six knifes. After sterilization, cover  14  is opened and rotated behind back shell  32 . Lever  44  is rotated such that tool floor  55  is in a raised position and substantially perpendicular to front shell  31  and back shell  32 . Kitchen tools  30  are raised up and partially out of sterilizer  10  for ease of retrieval.  
         [0034]     What has been illustrated and described herein is a knife and kitchen tool sterilizer and holder. While the invention has been illustrated and described with reference to certain preferred embodiments, the present invention is not limited thereto. In particular, the foregoing specification and embodiments are intended to be illustrative and are not to be taken as limiting. Thus, alternatives, such as structural or mechanical equivalents and modifications will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, such alternatives, changes, and modifications are to be considered as forming a part of the present invention insofar as they fall within the spirit and scope of the appended claims.