Abstract:
The invention relates to a UV-lamp sterilizing appliance that is used to destroy bacteria. The appliance presents a simple design which can facilitate the sterilization of any elongate personal article such as toothbrush, chopsticks and the like for sanitation by simply putting them into the appliance. The appliance also includes a protective shield surrounding the UV-lamp. The shield is designed to prevent any damage to the user&#39;s sight from the leakage of the UV-lamp radiation and also to retain the capacity to destroy bacteria sufficiently. The shield also protects the lamp from damage. Thereby the appliance according to the invention can be used easily and safeguards the user&#39;s health.

Description:
TECHNICAL FIELD OF THE INVENTION  
       [0001]     This invention is a disinfection device, to be specific, an Ultraviolet Disinfection Device that uses ultraviolet light to kill germs and includes a protective shield.  
       BACKGROUND OF THE INVENTION  
       [0002]     It is well known that ultraviolet (a.k.a. UV) light of a particular range of wavelength, called germicidal UV light, can destroy germs. The Ultraviolet Disinfection Device of the present invention is a device that kills germs by means of the germicidal UV light that is generated by the ultraviolet lamp. Elongated personal articles, such as toothbrush and chopsticks, can be disinfected by inserting them into the device.  
         [0003]     Currently, there are two types of ultraviolet disinfection devices for disinfecting long objects such as toothbrushes and chopsticks. One type uses an enclosed case, with several hooks or other fixtures inside for hanging or holding the objects to be disinfected. The user only need to place the objects properly, close the cover, and turn on the ultraviolet lamp. Disinfection is achieved by illuminating the objects to be disinfected for a certain period of time with the ultraviolet light that is generated by the ultraviolet lamp inside the device. Although this type of device can disinfect effectively, it is not convenient. The user has to spend time opening and closing the cover, as well as hanging or placing the objects properly. The other type of device, which is more popular, uses a simpler design. By inserting the objects to be disinfected into the disinfecting cells of the device through the openings on the top cover of the device, the portions of these objects that are exposed to the ultraviolet light can be disinfected. But that introduces another more serious issue that concerns safety. Since ultraviolet light can leak from the holes through which the objects are inserted for disinfection, it can hurt the eyes of the user if the user looks into the ultraviolet lamp of the device through those holes.  
         [0004]     In view of the above, it is apparent that there exists a need for an ultraviolet disinfection device that provides effective disinfection and is both convenient and safe to use. This invention addresses this need.  
       OBJECTIVES AND SUMMARY OF THE INVENTION  
       [0005]     The primary objective of the present invention is to provide an ultraviolet disinfection device for effective disinfection of objects such as toothbrushes and chopsticks. Another objective is to provide an ultraviolet disinfection device that is both convenient and safe to use. It can both tremendously reduce leakage of the ultraviolet light, thus protecting the user&#39;s eyes, and yet maintains good disinfection capability.  
         [0006]     The above objectives can be accomplished in the ultraviolet disinfection device of this invention. The most salient feature of this ultraviolet disinfection device is the protective shield which surrounds the ultraviolet lamp that generates the germicidal UV light. The said protective shield provides two protective functions. Firstly, it protects the user&#39;s eyes by preventing the ultraviolet light generated by the ultraviolet lamp from leaking directly through the openings of the top cover of the ultraviolet disinfection device. Secondly, it protects the ultraviolet lamp, which it surrounds, from being damaged by mechanical forces exerted by any object that is inserted in any of the disinfection cells of the ultraviolet disinfection device.  
         [0007]     A preferred embodiment of the ultraviolet disinfection device of the present invention can be illustrated as comprising the following major components: 
        A base that is at the bottom of the ultraviolet disinfection device. At the bottom of this base is a base bottom cover. Above this base bottom cover is a circuit board. Above this circuit board is a base body. The top surface of the base body is a platform from where supporting poles protrude upwards. There is a pushbutton switch on the base body and is connected to the circuit board that is inside the base.     A device body that is placed on top of the base body. This device body includes a base ring that is at the bottom of the device body, and a center shell that is on top of the base ring. The base ring is preferably translucent to visible light but opaque to UV light.     A reflection cup that is placed inside the device body. This reflection cup includes two connected portions: a reflection cup ring and a reflection cup body.     A top cover, which can be removable, that is above the reflection cup and on top of the center shell. This top cover contains disinfection cell holes, which are on top of the disinfection cells. Near the bottom rim of the top cover, there are locking hooks. From the bottom of the top cover near the disinfection cell holes, there are two triggering hooks protruding downwards.     A protective shield that is mounted on top of the supporting poles. It features (1) a shield body, preferably cylindrical, with a number of fixing arms protruding horizontally outwards from the top region of the outer surface of the cylindrical body, (2) a stack of horizontal slats, ring shaped if the shield is cylindrical, strategically deployed at non-uniform vertical spacing below the lower rim of the said cylindrical shield body and (3) a number of thin vertical links protruding downwards from the bottom circular rim of the said cylindrical shield body. The said horizontal, thin, ring-shaped circular slats are linked together and kept at strategic vertical spacing by the said thin vertical links.     A germicidal ultraviolet lamp that is fitted inside the shield body by means of a lamp holder.     A protective shield cover is on top of the shield body. It has the same shape as the top portion of the shield body including its fixing arms.     A mechanical triggering device that is placed inside one of the supporting poles. This triggering device includes a pivot supporting frame and a pivoted trigger plank.        
 
         [0016]     By this simple design, this invention can conveniently disinfect personal belongings and promote personal hygiene by simply inserting any long objects such as toothbrushes and chopsticks into a disinfection cell of this device. Meanwhile, the protective shield that surrounds the ultraviolet lamp greatly reduces the leakage of ultraviolet light, thus preventing damage to the user&#39;s eyes. Yet it still provides enough disinfection power. Thus, in addition to the convenience of usage, this ultraviolet disinfection device also protects the user&#39;s health.  
         [0017]     A preferred embodiment of the present invention is illustrated in the accompanying drawings and is now described in detail.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a top view of a preferred embodiment of this ultraviolet disinfection device.  
         [0019]      FIG. 2  is an exploded view of the ultraviolet disinfection device that is shown in  FIG. 1 .  
         [0020]      FIG. 3  is a sectional view along the axis  3 - 3  of  FIG. 1 .  
         [0021]      FIG. 4  is an illustration of the mechanism for the ultraviolet disinfection device in  FIG. 3  to prevent the ultraviolet light generated by the ultraviolet lamp from leaking directly out of the device.  
         [0022]      FIG. 5  is a sectional elevation view of the protective shield of the ultraviolet disinfection device that is shown in  FIG. 2 .  
         [0023]      FIG. 6  is a perspective sectional view along the axis  6 - 6  of  FIG. 1 .  
         [0024]      FIG. 7  illustrates the operation of the mechanical triggering device that is placed inside one of the supporting poles, which is shown in  FIG. 6 .  
         [0025]      FIG. 8  illustrates the strength of the ultraviolet light that leaks from a preferred embodiment of the ultraviolet disinfection device right outside the disinfection cell holes with the protective shield removed.  
         [0026]      FIG. 9  illustrates the strength of the ultraviolet light that leaks from a preferred embodiment of the ultraviolet disinfection device right outside the disinfection cell holes with the protective shield installed.  
         [0027]      FIG. 10  shows a cross section of the ultraviolet disinfection device.  
         [0028]      FIG. 11  shows a cross section of the ultraviolet disinfection device with an exemplary arrangement of horizontal slats.  
         [0029]      FIG. 12  shows a cross section of the ultraviolet disinfection device with another exemplary arrangement of horizontal slats. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]     The invention is illustrated through a description of a preferred embodiment in which the device is designed around a cylindrical protective shield. Please refer to  FIG. 1  first. This figure shows the top view of this ultraviolet disinfection device  100 . In this embodiment of the invention, there are four disinfection cells  35  and therefore four openings on the top cover of the device.  
         [0031]     Please then refer to  FIG. 2  and  FIG. 3 .  FIG. 2  is an exploded view of the preferred embodiment of the ultraviolet disinfection device that is shown in  FIG. 1 .  FIG. 3  is a sectional view along the axis  3 - 3  of  FIG. 1 . The device has a base  1  at the bottom of the ultraviolet disinfection device  100 . At the bottom of base  1  is a base bottom cover  16 . Above the base bottom cover  16  is a circuit board  15 . There is a micro-switch  18  inside the base  1  (as shown in  FIG. 6 ). The micro-switch  18  is connected to the circuit board  15 . Above the circuit board  15  is a base body  10 .  
         [0032]     The top surface of the base body  10  is raised to form a platform  14 . On the platform  14  there are two sets of supporting poles  13 A and  13 B. On top of each supporting pole  13 A there is a supporting pole extension  17 . Each supporting pole  13 B has a triggering hook holding slot on the outer side of the top of supporting pole  13 B. On the rim of the platform  14  there are several base connection holes  12  to connect to the base ring  54  that is placed inside of platform  14 . In one corner of base body  10  there is a pushbutton switch  1 I 1  that is connected to the circuit board  15  that is placed inside base  1 . A mechanical triggering device  6  is placed inside one of the supporting poles  13 B. This mechanical triggering device  6  consists of a pivot supporting frame  60  and a trigger plank  61 . The pivot supporting frame  60  is placed inside one of the supporting poles  13 B. At the central part near the top edge of each of the two sides of the top portion of the pivot supporting frame  60  that are facing each other, there is a pivot hole  62 . The two pivot holes  62  respectively on the said two opposite sides are in line. The two trigger plank pivot shafts  63  that protrude from the central part of the two narrower sides of the trigger plank  61  is respectively engaged into the two pivot holes  62 . Thus, the trigger plank  61  can turn about the axis of the pivot.  
         [0033]     A device body  5  is installed on top of base body  10 . This device body  5  includes a base ring  54  that is at the bottom of device body  5  and a center shell  50  that is on top of base ring  54 . Base ring  54  is made of a material that is preferably translucent to visible light but opaque to UV light. The footprint of center shell  50  and base ring  54  matches the shape of the round platform  14  that is on top of base body  10 . Thus after they are attached together and aligned, base  1  and device body  5  can be connected together by inserting screw bolts through the base ring connection hole  56  inside the base ring fixing block  55  on the rim of the base ring  54 , and through the base connection hole  12  on the platform  14 .  
         [0034]     Furthermore, the preferred embodiment includes several cover lockers  52  intruding inside, as well as several slightly bulging reflection cup supporters  51  on the inner surface of the centre body  50  near the top. In the middle of each cover locker  52  there is a cover locking slot  53 . Reflection cup supporter  51  is used to hold reflection cup  3  to mount it inside device body  5 . Cover locking slot  53  is an irregular slot. One end of the slot is wider than the other. Thus the locking hook  24  beneath the top cover  2  can be placed inside it to lock the top cover  2  on top of the device body  5 . The reflection cup  3  is installed inside device body  5 . The reflection cup unit  30  has two connected portions: reflection cup ring  31  and reflection cup body  32 . Reflection cup ring  31  is a cylinder with two indentations on its surface at the opposite ends of a diameter of the reflection cup  31 . The two indentations form two reflection cup notches  33 , which engage with the two intruding cover lockers  52  on the top portion of the center body  50 . On the bottom of the reflection cup body  32  there is a cross-shaped, in this embodiment, hole which is the supporting pole passage hole  36  (as shown in  FIG. 3 ).  
         [0035]     When the reflection cup  3  is installed into the device body  5 , the supporting poles  13 A and  13 B pass through the supporting pole passage hole  36  to fit into the supporting pole holding cavities  34  inside the reflection cup body  32 . The space between these supporting pole holding cavities  34  are disinfection cells  35 . The objects to be disinfected will be placed here for disinfection.  
         [0036]     In a preferred embodiment, an ultraviolet protective shield  4  comprises (a) a shield body  40 , in this embodiment it is cylindrical, with four fixing arms  42 A and  42 B protruding horizontally from the top region of the outer surface of the cylindrical body to form a cross shape as view from above, (b) a stack of horizontal, ring-shaped, preferably thin, circular slats  41  strategically deployed at non-uniform vertical spacing below the lower circular rim of the shield body  40  and (c) a number of vertical links, preferably thin, protruding downwards from the bottom circular rim of the shield body  40 . The various levels of horizontal circular slats  41  are linked together and kept at strategic vertical spacing by the said vertical links. The four fixing arms  42 A and  42 B of the protective shield  4  are mounted on top of the four supporting poles  13 A and  13 B, respectively, with the supporting pole extensions  17  priorly glued on top of the supporting poles  13 A, as extended parts of supporting poles  13 A.  
         [0037]     The ultraviolet lamp  47  has its two adjacent electrodes located at one end. Each electrode has a connecting wire. Lamp holder  48  embraces the top part of the ultraviolet lamp and its two electrodes. The lamp holder  48 , together with the ultraviolet lamp  47 , is inserted and fitted into the hollow center of the shield body  40  of the ultraviolet protective shield  4 , with the whole length of the ultraviolet lamp  47  being surrounded by the stack of slats  41  of the ultraviolet protective shield  4 . The two connecting wires of the ultraviolet lamp  47  are threaded through the central cavity of one of the supporting pole  13 B to reach the circuit board  15  from where suitably conditioned electrical power for the ultraviolet lamp is obtained during disinfection periods. Since the electronics of the UV lamp driver is well-known in the trade, it is not described here. A protective shield cover  45  completely covers the top parts of ultraviolet protective shield  4  including its four fixing arms  42 A and  42 B. On two opposite arms of the protective shield cover  45  there are body connection holes  46 , which align with the two body connection holes  43  on the fixing arms  42 A, through which two fixing screws are applied.  
         [0038]     Top cover  2  is placed above the reflection cup  3  and on top of the center shell  50 . There are several disinfection cell holes  21  on the cover body  20 , which allow passage tubes  23  to extend into disinfection cells  35 , leading objects to be disinfected into the disinfection cells  35 . Close to the rim on the bottom side of the top cover  2  there are two downward extensions whose lower parts are the locking hooks  24 , which lock respectively into the cover locking slots  53 . The locking hooks  24  first enter the wider end of the cover locking slots  53 . When top cover  2  is turned in the clockwise direction, the locking hooks  24  move towards the narrower ends of the cover locking slots  53 . Thus the hooks on the bottom of locking hooks  24  press against the inner ceiling near the cover locking slots  53 , locking the top cover  2  and the device body  5  together. Additionally, on the bottom side of the top cover  2  near two of the disinfection cell holes  21 , there are two downward extensions whose lower parts are the triggering hooks  22 . After the top cover  2  and the center body  50  are locked together, the hooks at the bottom of the two triggering hooks  22  are respectively inserted into the triggering hook accepting slots at the top part of the two supporting poles  13 B and the fixing arms  42 B.  
         [0039]     Please then refer to  FIG. 4  and  FIG. 5 .  FIG. 4  illustrates how the ultraviolet protective shield  4  of the ultraviolet disinfection device  100  prevents the ultraviolet light generated by the ultraviolet lamp  47  from leaking directly out of the device.  FIG. 5  is a sectional elevation view of the ultraviolet protective shield  4 . The ultraviolet protective shield  4  is made of a tough and strong material that is opaque to ultraviolet light and may be transparent, translucent or opaque to visible light. The stack of ring-shaped circular slats  41  of the ultraviolet protective shield  4  surrounds the ultraviolet lamp  47 . The vertical thickness of the ring-shaped circular slats  41  is preferably as small as possible to minimize blockage of the ultraviolet light rays that shine into the disinfection cells  35 , but thick enough to provide the required mechanical strength. To determine the appropriate thickness, factors such as the strength of the material, the fabrication method, the actual size of the shield and the overall cost allowed have to be considered. This embodiment employs injection molding of polycarbonate (PC) resin with stabilizer against UV added. For an outer diameter of 20 mm for the slats  41 , it is found that the optimal vertical thickness of the slats  41  is slightly less than 1 mm around the inner circumference of the circular slats and progressively reduced to about 0.5 mm around the outer circumference.  
         [0040]     The various levels of horizontal slats  41  are linked together and kept at strategic vertical spacing by the said thin vertical links. The horizontal slats  41  are said to be strategically spaced because the spacing density is not uniform for all the various levels: densest at the top level and progressively less dense for the lower levels (see  FIG. 3 ). The specific horizontal width of each slat  41  in the stack and the specific vertical spacing of that slat from its neighbors are carefully selected so that all the slats in the stack together form a complete blockage against the ultraviolet light rays generated by the ultraviolet lamp  47  in all possible direct paths leading to the user&#39;s eyes through the disinfection cell holes  21  of the top cover  2 , while the number of slats  41  in the stack is minimized so that the blockage effect is very little for the light rays that enter the disinfection cells  35 . The vertical spacing of the different levels of the slats is not uniform because for any fixed point of view above any of the disinfection cell holes  21 , the angle of view for a point at the ultraviolet lamp  47  varies with the vertical position of that point. By simple trigonometry, the optimal spacing of the different levels of the slats so, as to form a good-enough complete shield against the direct leakage of ultraviolet light rays can be worked out. As shown in  FIG. 4 , the slats prevent the ultraviolet light  7  generated by the ultraviolet lamp  47  from leaking through the disinfection cell holes  21  into the user&#39;s eyes. At the same time, most of the ultraviolet light is allowed to pass through the space between the slats  41  to reach the disinfection cells  35  and shine onto the major parts of the objects to be disinfected if the latter are inserted into the disinfection cells  35 .  
         [0041]     Please refer to  FIG. 6  which is a perspective sectional view along the axis  6 - 6  of  FIG. 1 . In  FIG. 6 , a supporting pole  13 B is sectioned to show its interior where the mechanical triggering device  6  is accommodated. As already described in a previous paragraph, the mechanical triggering device  6  consists of the pivot supporting frame  60  and the trigger plank  61 . The pivot supporting frame  60  keeps the trigger plank  61  in the proper position and provides a pivot axis for the trigger plank  61  to turn about. After the top cover  2  is placed correctly to cover the device body  5 , turning the top cover  2  in the clockwise direction will lock the top cover  2  and the device body  5  together. The two triggering hooks  22  will also be inserted respectively into the triggering hook accepting slots at the top part of supporting poles  13 B and fixing arms  42 B. As shown in  FIG. 7 , triggering hook  22  pushes the top part  64  of the trigger plank  61  to the left. Thus the bottom part  65  of trigger plank  61  moves to the right because of the leverage action. When it presses the micro-switch  18  inside the base  1 , the circuit in the circuit board  15  is turned on, and the automatic disinfection program starts to cycle.  
         [0042]     Finally, please refer to  FIG. 8  and  FIG. 9 . They illustrate respectively the strength of the ultraviolet light that leaks from this ultraviolet disinfection device  100  right outside the disinfection cell holes  21  before and after installation of the ultraviolet protective shield  4 . In  FIG. 8 , where the ultraviolet disinfection device  100  is without the ultraviolet protective shield  4 , the ultraviolet strength readings right outside the disinfection cell holes  21  average to 160 μWcm −2 . But when the ultraviolet disinfection-device  100  is with the ultraviolet protective shield  4  installed inside, the ultraviolet strength readings right outside the disinfection cell holes  21 , as shown in  FIG. 9 , average to 20 μWcm −2 . This demonstrates that the ultraviolet protective shield  4  can substantially reduce the leakage of the ultraviolet light from the ultraviolet disinfection device  100 .  
         [0043]     Based on the abovementioned structure, ultraviolet disinfection device  100  utilizes a simple design to automatically disinfect long objects such as toothbrushes and chopsticks by simply inserting the objects into the disinfection cells  35  of this device  100 . It is very easy to disinfect personal belongings. By utilizing the ultraviolet protective shield  4  around the ultraviolet lamp  47  with a shield body  40 , this design both provides sufficient disinfection power and reduces substantially the leakage of ultraviolet light that may otherwise hurt the user&#39;s eyes. This ultraviolet disinfection device  100  is both convenient and safe to use, and is also good for the user&#39;s health.