Patent Publication Number: US-9408458-B2

Title: Surface-cleaning device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/671,125 filed Nov. 7, 2012 (published as US 2013/0061408 on Mar. 14, 2013, to issue as U.S. Pat. No. 9,161,612 on Oct. 20, 2015), which claimed the benefit and priority of U.S. Provisional Patent Application No. 61/565,268, filed Nov. 20, 2011. The entire disclosures of each of the above applications are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to cleaning machines, and more particularly to a surface cleaning machine particularly well-suited for cleaning barbeque grills. 
     DISCUSSION OF RELATED ART 
     Automated cleaning machines have become popular for cleaning surfaces such as carpeted and hard wood floors. However, none of the prior art devices is well suited for automatically cleaning a barbeque grill, which can be an arduous task particularly if the grill is allowed to cool. Perhaps the best time to clean a grill is immediately after cooking when food and gristle is still warm and easier to remove. Yet that is also the best time to eat the food that has just been cooked. Such prior art floor cleaning machines further do not provide for one or more cleaning elements to simultaneously serve as the cleaning and motive force for the device. 
     Therefore, there is a need for a device that automatically cleans a barbeque grill or other surface for a preset period of time, and that can withstand the heat generated by a barbeque that has just been used. Such a needed device would be easy to use, relatively inexpensive to manufacture, and would allow for easily replacing detachable cleaning brushes and contact pads as necessary. Such a needed invention would be easy to store when not in use, and would provide a means for not becoming stuck when encountering the edge of the grill or other obstruction. The present invention accomplishes these objectives. 
     SUMMARY OF THE INVENTION 
     The present invention is a device for cleaning a surface, such as a barbeque grill. A substantially hollow enclosure has at least a lower side, an upper side, and a peripheral edge. The enclosure contains a plurality of motors each having a rotational shaft selectively fixable with a rotatable brush. Each brush has a plurality of bristles radially projecting from a rotational axis thereof, and at least a portion of the bristles of each brush project below the plane of the lower side of the enclosure. The lower side of the enclosure may further include a recess for each brush. 
     Preferably the rotational axis of each brush and the rotational shaft of each motor are substantially parallel to the plane of the lower side of the enclosure. Further, preferably the plurality of motors with brushes is an odd number, such as three each at relative angles of 60 degrees, whereby each brush is capable of moving the enclosure in a direction different from any of the other brushes. 
     The enclosure further contains a power source, such as a plurality batteries. The enclosure further contains a circuit adapted for connecting power from the power source to each of the motors for a preset period of time upon actuation of an electrical switch connected thereto that is accessible from outside of the enclosure. The circuit is adapted to run each motor in a first direction and then an opposing direction, such as by switching the polarity of the power applied to each motor, preferably every one to two seconds, for example. 
     Preferably the circuit further includes an indicator, such as one or more LED lamps, for indicating one of a plurality of program times. As such, with multiple actuations of the switch, each program time is advanced in sequence, the indicator indicating the currently-elected program time and the circuit running the motors back and forth for the currently-selected program time. 
     In use, with the enclosure placed upon the surface and with the switch actuated, the circuit runs each motor in the first direction and then alternately in the opposing direction, such that the brushes simultaneously support and move the device along the surface and clean the surface. The enclosure, if becoming stuck at an obstruction, eventually turns around due to the alternating directions of the motors. In one exemplary embodiment, pressing the switch to select a program time results in the indicator indicating the selected program time for five seconds, after which time the control circuit actuates the motors for the programmed time, alternating the direction of each motor independently of the other motors. At any time, holding down the switch for more than three seconds, for example, directs the circuit to go into a sleep mode wherein the indicator and the motors are deactivated until the next press of the switch. A rack may be included for providing convenient storage for the device when not in use. 
     The present invention is a device that automatically cleans a barbeque grill or other surface for a preset period of time, and that can withstand the heat generated by a barbeque that has just been used. The present device is easy to use, relatively inexpensive to manufacture, and allows for easily replacing detachable cleaning brushes and contact pads as necessary. The present invention is easy to store when not in use, and provides a means for not becoming stuck when encountering the edge of the grill or other obstruction during use. Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the invention; 
         FIG. 2  is a perspective view of the invention, illustrated with an enclosure omitted for clarity of illustration; 
         FIG. 3  is a bottom perspective view of the invention, partially cut-away; 
         FIG. 4  is a bottom plan view of the invention, illustrated with two of three contact pads omitted for clarity of illustration; 
         FIG. 5  is a front elevational view of a rack for storing the enclosure; 
         FIG. 6  is a perspective view of the rack, illustrated as supporting the enclosure; 
         FIG. 7  is a top plan view of  FIG. 2 ; 
         FIG. 8  is a diagram of a circuit of the invention; 
         FIG. 9  is a functional block diagram of the steps of a microcontroller of the circuit; and 
         FIG. 10  is a side elevational view of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Illustrative embodiments of the invention are described below. The following explanation provides specific details for a thorough understanding of and enabling description for these embodiments. One skilled in the art will understand that the invention may be practiced without such details. In other instances, well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number respectively. Additionally, the words “herein,” “above,” “below” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. When the claims use the word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list and any combination of the items in the list. 
       FIGS. 1 and 2  illustrate a device  10  for cleaning a surface  20 , such as the top surface  26  and side surfaces  27  of a plurality of barbeque grill rods  25 . Other surfaces  20  may include all types of hard floors, for example, such as wood, tile, laminate, concrete, or the like. 
     A substantially hollow enclosure  30  has at least a lower side  32 , an upper side  38 , and a peripheral edge  35 . The enclosure  30  is preferably made from a high heat-resistant plastic material, such as a high-temperature polyurethane (for example, TC-895 A/B Black produced by BJB Enterprises, Inc., of Tustin, Calif.). An insulator  130  ( FIG. 3 ) may additionally be included proximate the lower side  32  of the enclosure  30  to insulate the interior of the enclosure  30  from heat emanating from the surface  20 . The peripheral edge  35  may be rigid and reinforced with ribs (not shown) or other reinforcement structures to absorb kinetic energy of the device  10  upon contacting an obstruction  28  ( FIG. 1 ). Further, the enclosure may include at least one handle  180  ( FIGS. 1 and 10 ) for allowing convenient and clean lifting of the device  10  from the surface  20 . 
     The enclosure  30  contains a plurality of motors  40  each having a rotational shaft  50  selectively fixable with a rotatable brush  60 . Each brush  60  has a plurality of bristles radially projecting from a rotational axis  80  thereof, and at least a portion of the bristles  70  of each brush  60  project below a plane  33  ( FIG. 10 ) of the lower side of the enclosure  30 . The lower side  32  of the enclosure  30  may further include a recess  90  for each brush  60  ( FIGS. 3 and 4 ). Preferably the bristles  70  of each brush are made of brass, whereby the bristles  70  are suitable for use on a barbeque grill surface  20 . Alternately, the brushes may be made of some other material, such as a softer material, for use on a softer surface  20  without scratching thereof, for example. 
     Preferably the rotational axis  80  of each brush  60  and the rotational shaft  50  of each motor  40  are substantially parallel to the plane of the lower side  32  of the enclosure  30 . Further, preferably the plurality of motors  40  with brushes  60  is an odd number, such as three each at relative angles a of preferably 60 degrees ( FIG. 7 ), whereby each brush  60  is capable of moving the enclosure  30  in a direction different from any of the other brushes  60 . 
     The enclosure  30  further contains a power source  100 , such as a plurality of either rechargeable or non-rechargeable batteries  105 , such as D-cell type batteries for example. In an embodiment where each battery  105  is a rechargeable battery, a recharging port  200  ( FIG. 1 ) may be included that is electrically connected with each battery  105  such that an external power source  201  may be selectively fixed with the recharging port  200  to recharge each battery  105 . Alternately, the power source  100  may be a power cord (not shown) that may be plugged into a power outlet, for example, for powering the motors  40  directly. 
     The enclosure  30  further contains a circuit  1   10  adapted for connecting power from the power source  100  to each of the motors  40  for a preset period of time T n upon actuation of an electrical switch  120  connected thereto. The circuit  110  is adapted to run each motor  40  in a first direction Di and then an opposing direction D 2  ( FIG. 3 ), such as by switching the polarity of the power applied to each motor  40 , preferably every one to two seconds, for example. 
     Preferably the circuit  110  further includes an indicator  140 , such as one or more LED lamps, or the like, for indicating one of a plurality of program times P n . As such, with multiple actuations of the switch  120 , each program time Pi, P 2 , . . . P n is advanced in sequence, the indicator  140  indicating-such as by flashing a corresponding number of times or illuminating in a particular color such as red, green, or yellow—the currently-selected program time P n and the circuit  110  running the motors  140  back and forth for the currently-selected program time P n . In such an embodiment the circuit  110  further includes a timer function  114 . For example, in an embodiment having three program times P n , Pi may be five minutes, P 2  seven minutes, and P 3  ten minutes. 
     In use, with the enclosure  30  placed upon the surface  20  and with the switch  120  actuated, the circuit  110  runs each motor  40  in the first direction Di and then alternately in the opposing direction D 2 , such that the brushes  60  simultaneously support and move the device  10  along the surface  20  and clean the surface  20 . The enclosure  30 , if becoming stuck at an obstruction  28 , eventually turns around due to the alternating directions Di,D 2  of the motors  40 . In one exemplary embodiment, pressing the switch  120  to select a program time P n  results in the indicator  140  indicating the selected program time P n  for five seconds, after which time the control circuit  1   10  actuates the motors  40  as specified above for the programmed time P n . At any time, holding down the switch  120  for more than three seconds, for example, directs the circuit  110  to go into a sleep mode wherein the indicator  140  and the motors  40  are deactivated until the next press of the switch  120 . 
     In one embodiment the circuit  110  is adapted to change the direction of any of the plurality of motors  40  independently of the directions of the other motors  40 . 
     Moreover, the circuit  110  may further include a random number generator  115 , such that the direction of any of the plurality of motors  40  may be toggled in a substantially random manner, or in what appears to be a random manner but is rather a predetermined repeating program that simulates a random program. As such, the enclosure  30 , if becoming stuck at an obstruction  28 , eventually turns around due to the seemingly random directions Di,D 2  of the motors  40  and resulting seemingly random path of the enclosure  30  on the surface  20 . 
     The circuit  110  may further include a microcontroller  111  ( FIG. 8 ) to control an H-bridge arrangement  112 , solid state relays, or mechanical relays (all not shown) that provide power to the motors  40 . The microcontroller  111  may further be used to detect activation of the switch  120 , and to illuminate the indicator  140 . The circuit  110  may further include a voltage translator or transformer  113 , and optionally a voltage regulator  116 , for providing differing voltages to the control circuit  1   10  and to the motors  40 , as necessary. 
     In one embodiment, the lower surface  32  of the enclosure  30  includes at least one selectively detachable contact pad  150  ( FIGS. 3 and 4 ), which supports the enclosure  30  on the surface  20  in cooperation with the brushes  60 . The at least one contact pad  150  serves to temper the amount of contact each brush  60  has with the surface  30  to regulate the speed that the brushes  60  move the device  10  along the surface  20 . As each contact pad  150  wears or becomes fouled, it may be replaced with a new contact pad  150  by removing mechanical fasteners (not shown), or the like, that hold each contact pad  150  to the lower surface  32  of the enclosure  30 . 
       FIGS. 5 and 6  illustrate a rack  160  that may be included for storing the device  10  when not in use. Such a rack  160  may include a hook arrangement  165  for suspending the rack  160  and the device  10  from an object (not shown), such as a fence or the like. 
     In one embodiment, the lower side  32  of the enclosure  30  further includes a plurality of sensors  170  ( FIG. 3 ) for detecting an edge  29  of the surface  20 . The circuit  110  is electrically connected with each sensor  170  and adapted to run at least one of the plurality of motors  40  in an opposing direction upon detection of the edge  29  of the surface  20 . For example, each sensor  170  may be a capacitive or inductive sensor that detects the edge of the metallic barbeque grill  25 . The circuit  110  may induce a charge or other signal into the barbeque grill  25  through the brass brushes  60 , facilitating detection of the edge  29  of the grill  25 . As such, the circuit  110  may be electrically connected with one or more of the brushes  60 . Other sensors  170  may be utilized as well, such as optical or ultrasonic sensors, or the like, as are suitable for detecting such an edge  29 . 
     While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. For example, three motors and brushes are shown in the drawings, but any other suitable number of motors and brushes could be used, as could any suitable orientation thereof. Accordingly, it is not intended that the invention be limited, except as by the appended claims. 
     Particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the invention encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the invention. 
     The above detailed description of the embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above or to the particular field of usage mentioned in this disclosure. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. Also, the teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments. 
     All of the above patents and applications and other references, including any that may be listed in accompanying filing papers, are incorporated herein by reference. 
     Aspects of the invention can be modified, if necessary, to employ the systems, functions, and concepts of the various references described above to provide yet further embodiments of the invention. 
     Changes can be made to the invention in light of the above “Detailed Description.” While the above description details certain embodiments of the invention and describes the best mode contemplated, no matter how detailed the above appears in text, the invention can be practiced in many ways. Therefore, implementation details may vary considerably while still being encompassed by the invention disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. 
     While certain aspects of the invention are presented below in certain claim forms, the inventor contemplates the various aspects of the invention in any number of claim forms. Accordingly, the inventor reserves the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the invention.