Abstract:
A tilt sensor for a cleaning device makes use of an optical sensor to interrupt operation of the device. In one implementation, the tilt sensor shuts off a UV light included in the cleaning device&#39;s operations. The tilt sensor includes a housing with at least one chamber defined therein. A sliding or moving element is located in the chamber. The optical sensor is operatively associated with the chamber so that, in response to certain movement of the element within the chamber, the optical sensor signals the tilt sensor to turn off the UV light.

Description:
FIELD 
     The invention relates to a tilt sensor for a cleaning device. 
     BACKGROUND 
     Cleaning devices, such as vacuums, are sometimes equipped with additional operative features associated with their cleaning operations. One such additional feature is the ability to disinfect surface, drapes, or other media while otherwise cleaning, such disinfecting often being accomplished by means of UV radiation from a UV light source. One suitable disinfecting vacuum device is disclosed U.S. Patent Application Publication Nos. US-2007/0192987-A1, US-2008/0061252-A1, and U.S. Pat. Nos. 7,444,711, and 7,476,885. 
     The cleaning device in such disclosures is described as being equipped with switches that turn off the UV light source in response to certain conditions, including tilting of the surface associated with the UV light source. However, such switches often suffer from various drawbacks and disadvantages. 
     SUMMARY 
     In one implementation, a cleaning device utilizing a UV light source is equipped with a tilt sensor. When the tilt sensor is horizontal, a sliding element within the tilt sensor blocks light emitted from a photo-emitter. When the angle of the tilt sensor exceeds a predetermined angle relative to horizontal, the sliding element no longer blocks the light emitted from the photo-emitter, and the light reaches a photo-collector, thereby completing a circuit, which shuts off energy to the UV light source. The sensor is thus designed to shut off or deactivate the UV light source in response to a change in inclination of the cleaning device. 
     According to another implementation, the cleaning device comprises a vacuum, and the tilt sensor comprises a housing securable relative to the vacuum. The housing has a pair of chambers defined therein, an optical sensor located to define a detection zone within each of the chambers to detect variations in light, and an element located in the detection zone of each of the chambers and moveable in response to tilting of the vacuum. The tilt sensor is adapted to interrupt operation of the vacuum in response to the movement of the element. The detection zone may comprise a path between a photo-emitter and a photo-collector of the optical sensor. 
     The element of the tilt sensor may be configured to move relative to the chamber between a first position fully or partially obstructing the path and a second position less obstructing or not obstructing of the path. The chamber of the tilt sensor includes lower and upper walls, and the path extends between the walls. The lower wall of the tilt sensor slopes downwardly toward the path, the element adapted to be slidable toward the path in the absence of tilting and along the lower wall away from the path in response to sufficient tilting. The housing of the tilt sensor includes two opposing portions secured to each other to define the chamber, the opposing portions having at least two pairs of opposing surfaces defining an angle relative to each other, the angle located between the exterior of the housing and the chamber to inhibit entry of dust from the exterior of the housing into the chambers. 
     Additional features and advantages of the invention will be made apparent from the following detailed description of illustrative embodiments that proceeds with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing summary, as well as the following detailed description of the preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments that are presently preferred, it being understood, however, that the invention is not limited to the specific methods and instrumentalities disclosed. In the drawings: 
         FIG. 1  is a perspective view of one possible implementation of the tilt sensor located in a vacuum cleaner housing assembly; 
         FIG. 2  is an exploded  3  dimensional view of the tilt sensor of  FIG. 1 ; 
         FIGS. 3-5  are top, side, and end views, respectively, of the tilt sensor of the preceding FIGS; 
         FIG. 6  is a cross-sectional view taken along line  6 - 6  of the tilt sensor of  FIG. 5 ; 
         FIG. 7  is a cross-sectional view similar to  FIG. 6 , but showing the tilt sensor at an angle relative to horizontal; 
     
    
    
     DESCRIPTION 
     Referring now to the drawings, and to  FIG. 1  in particular, in one possible implementation, cleaning device  21  comprises an upright vacuum equipped with a UV light source  27  mounted to vacuum cleaning base  23 , as shown and described in U.S. Patent Publication Nos. 2007/0192987-A1, US-2008/0061252-A1, and U.S. Pat. Nos. 7,444,711, and 7,476,885, the disclosures of which are incorporated by reference herein. Tilt sensor  25  is mounted to base  23  and suitably enclosed by vacuum covers or housing (not shown for purposes of clarify). In this implementation, tilt sensor  25  is horizontal, but it should be appreciated that the location, orientation or angle of tilt sensor  25  can be varied to suit the application or cleaning device parameters. It will be appreciated that cleaning device  21  may assume any number of alternate forms, depending on the characteristics of the media to be cleaned, which media may include any number of floors, rugs, carpets, other surfaces, fabric, materials, furniture, and the like, in the broadest senses of such terms and with limitation thereto. 
     In the implementation illustrated in  FIG. 1 , when base  23  is tilted from horizontal by a sufficient amount, such as if the device  21  is raised at an angle off a floor, tilt sensor  25  interrupts operation of device  21 , in particular causing UV light  27  to be turned off. 
     Referring now to  FIGS. 2-6 , tilt sensor  25  comprises housing  29  with a pair of chambers  35  defined therein. Housing is formed of a top portion  31  and a bottom portion  33 . Housing  29  is suitably secured, such as by fasteners  45 , to circuit board  43  on top of housing  29 , and circuit board  44  on the bottom of housing  29 . 
     Disposed within interior chamber  35  of housing  29  is a sliding element  41 . When tilt sensor  25  is horizontal, sliding element  41  is located against bottom surface  42  of chamber  35 . Photo-emitters  37  are mounted to direct light from lower portion  33  generally upwardly, to be detected by corresponding photo-collectors  39 , which are mounted to receive light directed toward the upper portion  31  of chambers  35 . In this way, a light path  40  extends generally vertically across chambers  35 . Thus, when sliding element  41  is in the bottom of interior chamber  35  as shown, sliding elements  41  obstruct corresponding light paths  40 . 
       FIG. 7  shows a cross-sectional view of the tilt sensor  25  of  FIG. 6 , in which tilt sensor  25  is angled relative to horizontal. When the angle with horizontal is sufficient, sliding element  41  moves from its position obstructing light path  40  shown in  FIG. 6  to a non-obstructing position in a more radially distant portion of chamber  35 . When sliding element  41  is no longer sufficiently obstructing the light emitted from photo-emitter  37 , the light is received by photo-collector  39 , thereby completing an electronic circuit associated with optical sensor  38  of tilt sensor  25 . In response to the electronic circuit being completed, suitable means, such as by an electronic circuit or controller, are provided so that the power to the UV light source  27  ( FIG. 1 ) is shut off. 
     It should be readily understood that, although, in the illustrated example, the sliding element obstructs the light emitted from the photo-emitter when horizontal, other non-horizontal variations are possible. For example, the placement of the tilt sensor  25  can be altered from the front left side of the vacuum housing  23  as disclosed in  FIG. 1 , to another non-horizontal location on device  21 , which location may require that tilt sensor  25  itself be angled in order to ensure that sliding element  41  moves between first and second positions corresponding to allowing UV light operation and interrupting such operation, respectively. Furthermore, the “angle relative to horizontal” is sufficient to allow sliding element  41  to shift between the two states of operation. Tilt sensor  25  may also be tuned by varying the slope of surface  42  of chambers  35  by adjusting the sensitivities of photo-collectors  39  to respond to total or partial light obstruction, or by adjusting light characteristics of photo-emitters  37 . 
     The photo-emitter/photo-collector pairs comprising a corresponding optical sensor  38  preferably are matched to emit and receive the same light frequency. Suitable optical sensors  38  for this implementation can make use of any frequency of light from within the light spectrum, including gamma, x-ray, UV, visible, infrared, and radio waves. In one possible embodiment, optical sensor  38  uses light waves from the visible light spectrum, and more particularly from about 380 to about 750 nanometer wavelengths. In a preferred embodiment, optical sensor  38  emits light from the infrared spectrum, or more preferably from about 1 millimeter to about 750 nanometer wavelengths. 
     Housing  29  can be made from any suitable material, so long as there are suitable means for keeping chambers  35  from exposure to stray or ambient light in the operative range of optical sensors  38 . For this reason, in one preferred implementation, the material of housing  29  is selected so as not to allow for light transmittance or reflection. Non-limiting suitable materials include steel, aluminum, copper, plastics, resins and polymers. Polymeric materials are available with suitable non-transmittance/non-reflection characteristics. Housing  29  can also be manufactured by a variety of methods, including, but not limited to, being cast, machined, injection molded, and the like. The interior of housing  29 , which defines interior chamber  35 , is preferably a relatively smooth surface, with a low coefficient of static friction. The outer surface of element  41  is likewise preferably smooth. In this way, friction is reduced between sliding element  41  and interior surfaces of chamber  35 . This allows sliding element  41  within interior chamber  35  to respond more consistently to variations in tilt or changes in angle relative to horizontal, and interrupt operation of UV light source  27  when predetermined tilt conditions are met. 
     Housing  29  comprises upper portion  31  and lower portion  33  that when assembled, define the substantially cylindrical chamber  35 . Chamber  35  includes lower and upper walls, and is designed to receive sliding element  41  within a substantially conical portion. The mating surfaces of upper and lower portions  31 ,  33  define one or more angles to form a tortuous path  48  which inhibits light from outside housing  29  from entering chamber  35 . The design of interior chamber  35  prevents sliding element  41  from becoming lodged within chamber  35 . Furthermore, housing  29  may comprise two or more interior chambers  35 . Multiple chambers allow for redundancy and enhanced safety features of the present disclosure. 
     The two portions  31  and  33  are secured to each other in order to prevent outside light from entering the interior of tilt sensor  25 , and further to prevent exterior dust from entering interior chamber  35 . The introduction of exterior light or foreign particles such as duct interferes with the sensitive responsiveness of tilt sensor  25  and optical sensor disclosed herein. Optionally, housing  29  comprises one or more O-rings or washers between the two portions,  31 ,  33 , or is vacuum sealed. Housing  29  may be secured to cleaning device  21 , either directly or indirectly, in either a permanent or modular fashion. 
     Photo-emitter  37  and photo-collector  39  are electrically connected to suitable control or operational circuits so that tilt sensor  25  responds to tilting by a predetermined amount to interrupt operation of cleaning device  21 , in this case turning off UV light source  27 . Photo-collector  39  may be suitably shielded from exterior light, such as by opaque tape or other opaque covering. 
     The configurations and dimensions of chamber  35  and sliding elements  41  therein may be varied according to the particular applications intended. In the implementation shown in  FIGS. 2-7 , sliding element  41  is substantially pill shaped and has a circular horizontal cross-section and has an ellipsoidal vertical cross-section, and chambers  35  have opposing, conical surfaces extended toward respective light paths  40 . Element  41  may have an axial height between about 2 and 3 mm, including 2.5 mm, and have a circular cross-section with a diameter of about 7 mm. Elements  41  may likewise be disc-shaped or in the form of spheres in which latter case elements  41  are adapted to roll rather than slide within chambers  35  in response to tilting. The diameter of each of the chambers  35  may be between 14 and 15 mm. For the illustrated implementation, the angle of the conical surfaces of chambers  35  is selected to be about 70 degrees with respect to the vertical axis of the cones defined in the chambers  35 . Other angles are possible and suitable, depending on the configuration of the tilt sensor and its intended application. 
     The distance between the upper and lower surfaces of chambers  35  is selected to allow elements  41  to slide therein, but not so great as to cause element  41  to become jammed or lodged away of its seated position over light path  40  when sensor  21  is tilted. In the illustrated implementation, the height of chambers  35  at the location of light path  40  is about 4.5 mm. Again, any of these dimensions may be “tuned” to change the responsiveness of the tilt sensor to different orientations of cleaning device  21 , or to suit different locations or applications of sensor  21 . 
     Sliding element  41  can be made of any suitable material, including by way of non-limiting example, steel, aluminum, copper, plastics, and polymers. Sliding element  41  may be made of the same material as housing  29 , or may be made of different material than housing  29 . 
     As described above, various components of tilt sensor  25  containing an optical sensor may be modified and still maintain the spirit of the disclosed preferred embodiments. For example, the different optical sensors may be used, different light frequencies may be utilized, the placement of the tilt sensor may be altered, and three or more chambers may be included in the tilt sensor, etc. Furthermore, tilt sensor  25  containing an optical sensor may also be configured for alternate applications on cleaning device  21 , such as for controlling power to a beater bar, rolling brush, or vacuum motor, etc. 
     It will thus be apparent that there has been provided in accordance with the present invention a disinfecting device comprising a tilt sensor which achieves the aims and advantages specified herein. It will of course be understood that the foregoing description is of preferred exemplary embodiments of the invention and that the invention is not limited to the specific embodiments shown. Various changes and modifications will become apparent to those skilled in the art and all such variations and modifications are intended to come within the spirit and scope of the appended claims.