Abstract:
A floor care machine that includes a deck having a motor, a rotatable floor care element for engaging a floor surface, and a handle apparatus pivotally mounted to the deck is provided. Additionally, there are first and second sets of wheels toward the rear of the deck and on opposite sides of handle apparatus pivot attachment points. In addition to the attachment points, the handle apparatus and the deck are coupled together by a rigid handle link which is pivotally attached to the deck at one end and pivotally attached to the handle apparatus at the other end. The handle link communicates deck pivot forces between the deck and the handle apparatus, and in particular, communicates such forces resulting from a compressing or decompressing of a compressible component provided along the length of the handle apparatus. A tension applied to the compressible component is communicated to the deck as a pivot force that counters deck gravitational and floor suction effects induced by the rotation of the floor care element.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to a floor care machine, and in particular to a floor care machine which automatically maintains a substantially even pressure on the floor by a floor care element attached to the machine.  
         BACKGROUND OF THE INVENTION  
         [0002]    For operating a floor care machine such as for burnishing, waxing, cleaning or sanding a floor, it is desirable to control the amount of weight the machine places on the contacting pad or other floor care element of the machine in caring for the floor. Such weight control is important in controlling the pressure applied to the floor surface and in controlling the amperage draw of the motor of the floor care machine. Previously, such weight control has been generally accomplished by a floor care machine operator using a fixed handle on the floor care machine to manually determine the amount of pressure being applied to various floor areas. In particular, the operator controlled the floor care element pressure by lifting or pushing on the handle. The problem with this type of operator involvement is the floor care element pressure varies, e.g., because different operators place different pressures on the floor care element and because of operator fatigue as well as operator height. Floor care machines have been disclosed, such as in U.S. Pat. No. 4,658,459 filed Jan. 27, 1986, that include a plurality of torsion springs as an “urging member” for reducing reliance on the operator to provide appropriate floor care element pressure on the floor. However, due to the requirement that the torsion springs had to be preloaded prior to shipment, the floor polishing machine of U.S. Pat. No. 4,658,459 generally could not be sold partially assembled due to the risk of components flying apart during assembly by unskilled persons and/or by persons without the proper assembly tools and jigs. Moreover, the free ends of the torsion spring exert a high compression force on the floor care machine platform. Accordingly, some materials such as rotationally molded plastic may not hold up under such a high compression force without reinforcement. To alleviate this drawback, U.S. Pat. No. 5,674,120 filed Sep. 30, 1996 uses a gas spring instead of torsion springs. The gas spring is pivotally connected at one end to the handle of the machine and is pivotally connected to the body of the machine at its opposite end. The pivot point of the gas spring on the body is different than the pivot point of the machine handle.  
           [0003]    Notwithstanding the different designs that have been advanced for achieving uniform pressure on the floor by a floor care element, it is desirable to provide a floor care machine that is able to provide such uniform pressure, while being cost effective, stylish in appearance and which incorporates all other necessary machine functions.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention is a floor care machine that provides a coupling or a handle link between the floor care machine body and a handle apparatus which is pivotally mounted to the body. The handle link is part of a force generating system having a resilient compressible component (e.g., a compression spring) along the direction of the length of the handle apparatus, wherein the compressible component and the handle link cooperate for urging the body (or deck) of the floor care machine to pivot about the axis of a first set of wheels and thereby bias the front of the deck upwardly. The forces for urging the deck to pivot are used to counter balance opposing pivotal forces caused by the weight of the deck and the floor suction forces generated by the rotation of a floor care element that rotationally contacts the floor for administering the desired floor care when the machine is operating.  
           [0005]    Thus, it is an object of the present invention to provide a novel machine for the care of floor surfaces.  
           [0006]    It is further an object of the present invention to provide such a novel floor care machine which places a substantially even pressure on the floor surface by the floor care element substantially without regard to the pivotal position of the handle apparatus with respect to the deck of the floor care machine.  
           [0007]    It is further an object of the present invention to provide such a novel floor care machine which places even polishing force on the floor surface by the floor care element regardless of the unevenness of the floor surface.  
           [0008]    It is further an object of the present invention to provide such a novel floor care machine which automatically maintains even polishing pressure.  
           [0009]    It is further an object of the present invention to provide such a novel floor care machine which maintains even floor care element pressure without being dependent on operator involvement.  
           [0010]    It is further an object of the present invention to provide such a novel floor care machine having floor care element pressure which is not variable due to operation by different operators.  
           [0011]    It is further an object of the present invention to provide such a novel floor care machine having floor care element pressure which is substantially not variable due to operator fatigue.  
           [0012]    These and further objects and advantages of the present invention will become evident in light of the accompanying drawing and detailed description provided therewith. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 shows an exterior perspective view of the floor care machine of the present invention;  
         [0014]    [0014]FIG. 2 shows a side view of the floor care machine; and  
         [0015]    [0015]FIG. 3 shows a partially exploded view of the floor care machine thereby illustrating internal components. 
     
    
       [0016]    Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “lower”, “upper”, “above”, and other position related terms are used herein, it should be understood that these terms are to be understood in the contexts and orientations illustrated in the accompanying figures.  
       DETAILED DESCRIPTION  
       [0017]    An embodiment of the floor care machine  50  is shown in FIG. 1. The floor care machine  50  generally includes a body portion or deck  54  adapted to be moved along a floor  58  (FIG. 2), and, attached to the deck is a floor care element  62  including, e.g., a polishing pad, a brush, a burnishing pad, a sanding disk, a waxing pad, a floor scouring element, or the like which contacts the floor with a rotational motion when the floor care machine  50  is operable. Additionally, the deck  54  has attached thereto a handle apparatus  64  for guiding and controlling the deck  54 . The handle apparatus  64  is pivotally attached to the deck  54  at various locations on the deck (as will be described below) so that the handle apparatus can, e.g., pivot between (i) operating positions (wherein the below described handle  68  is generally within a range of 30 to 60 degrees from the horizontal but can be outside that range), and (ii) a transport position (wherein the handle  68  is substantially vertical).  
         [0018]    Among the components included in the handle apparatus  64  are:  
         [0019]    (a) an operator grip  66  by which an operator controls the floor care machine  50 ,  
         [0020]    (b) the handle  68  having a length the extends downwardly from the grip  66 , wherein the opposite end of the length connects to the assembly  70  described immediately below, and  
         [0021]    (c) an assembly or section  70  (FIG. 1, also denoted herein as an “attachment assembly” and “counter force assembly”) for both: (i) pivotally attaching the handle apparatus  64  to the deck  54 , and (ii) providing a force generating system  72 (or simply force system) for inducing a force which is a counter pivot force to the gravitational and floor suction forces that are generated generally forward of the wheels  108  during operation of the floor care machine  50 , wherein these latter two forces urge at least the deck  54  and the floor care element  62  to pivot about the rotational axis of the wheels  108  in a counterclockwise direction in the orientation of FIG. 2. Note that the force system  72  includes:  
         [0022]    (i) a force generating device  74  (FIG. 1) that is generally an extension of the handle  68  length further toward the deck  54 . The force generating device  74  includes portions, e.g., a compressible resilient component therein for generating forces in the direction of the handle length (e.g., along the axis  118  of FIG. 2 as described hereinbelow) that are used to counter balance the weight of the deck  54  and floor suction forces induced by the rotation of the floor care element  62 ; and  
         [0023]    (ii) a substantially rigid handle link  76  for transferring forces induced by the force generating device  74  to the deck  54  as will be described further hereinbelow.  
         [0024]    The deck  54  also includes a housing  78  which substantially contains the floor care element  62 . The housing  78  includes a sloping platform  82  having a downwardly extending skirt  84  about its perimeter, wherein the skirt includes a first skirt portion  86  surrounding the floor care element  62  and a second skirt portion  88  extending rearwardly, e.g., for attaching the handle apparatus  64  thereto (FIG. 3), wherein this second skirt portion includes paired planar sides ( 88   a   L ,  88   a   R ), ( 88   b   L ,  88   b   R ) and a rear skirting  88   c  (e.g., FIG. 3). A motor  90  is mounted at the center of and generally above the platform  82 . Floor care element  62  is operatively connected to motor  90  for rotation thereby and within housing  78 .  
         [0025]    The deck  54  further includes a substantially inverted cup-shaped housing or motor shroud  94  received on housing  78  for encasing motor  90 . In one embodiment of the present invention, the housing  94  generally includes a cylindrical shaped portion  98  and a generally box shaped portion  102 . Portion  102  includes a generally closed top  106 , a generally open bottom for receipt and mating on platform  82 .  
         [0026]    The floor care machine  50  further includes a first set of wheels  108  having a rotation axis located intermediate between the motor  90  and a second set of wheels  110 . When the floor care machine  50  is in an operable position, the first set of wheels  108  is generally at a level equal to or slightly lower than the level of floor care element  62 . Note that at least the front two-thirds of the floor care element  62  (i.e., from the 8 o&#39;clock to 4 o&#39;clock position thereof) engages the floor surface  58  when the floor care element  62  is rotated by motor  90 , more preferably substantially the entire side of floor care element  62  facing the floor  58  engages or contacts the floor. Moreover, the wheels  108  are rotatably secured to the skirt  84  of the housing  78 .  
         [0027]    For attaching the handle apparatus  64  to the deck  54 , the counter force assembly  70  includes mounts  116  that extend from the center axis  118  (FIG. 3) of the handle apparatus  64 , and span the rear skirting  88   c.  The mounts  116  are pivotally secured to the deck  54  via an axle  120  (FIG. 3) that is provided through the planar skirting sides  88   b   L  and  88   b   R  and additionally through an axle opening  122  in each mount  116 . As mentioned above, the counter force assembly  70  includes force system  72  which, in turn, includes the force generating device  74  that is generally provided along center axis  118  and below the handle  68  (FIG. 1). In particular, the force generating device  74  includes adjacent lower handle sides  130  (FIG. 3) which provide a substantially cylindrical chamber  136  (FIG. 2) therebetween, wherein this chamber extends: (a) from paired chamber end cap halves  142  (only one of which can be seen in FIG. 3) to (b) the brackets  146 . Note that the cylindrical chamber  136  has its center axis aligned with the center axis  118  of the handle apparatus  64 . Additionally note that each of the lower handle sides  130  has a guide slot  152  extending longitudinally from just below the brackets  146  and toward the end cap halves  142  for approximately ⅓ of the length of the cylindrical chamber  136  in the direction of the center axis  118 . Also, in the region  158  (FIG. 3) between the upper end of each guide slot  152  and its corresponding bracket  146 , each of the lower handle sides  130  provides for the cylindrical chamber  136  to have a larger radius than the lower portion  160  of the cylindrical chamber  136  (FIG. 2) below the regions  158 . Note that the lower end of the handle  68  is secured within the enlarged radius portion provided by the two regions  158  when these regions are secured together by anyone of various securing devices such as bolt assembly  164  (FIG. 3). In particular, the bolt assembly  164  secures the adjacent lower handle sides  130  with the handle  68  by remaining positioned in the bolt holes  168 ,  172 , and  176 .  
         [0028]    Provided within the lower portion  160  (and also part of the force generating device  74 ) are force generating components for inducing the counter pivot force mentioned above. In particular, the counter pivot force is provided by the generation of a force linearly along the center axis  118  by the compression of a compressible component such as compression spring  182 . However, it is within the scope of the present invention that another component such as a wave spring or other resilient component may be used in place of compression spring  182 , and such resilient components may have different resiliency characteristics depending, e.g., on the desired behavior of the floor care machine  50 . Also included in the force generating device  74  and within the lower portion  160  but above the spring  182  is a compression block  186  for compressing the spring  182  within the lower portion  160 . Thus, the compression block  186  has a diameter that may be only sufficiently smaller than the diameter of the lower portion  160  so that the compression block can freely slide therein. The compression block  186  is slidably secured to the guide slots  152  by bolt assembly  190  (FIG. 3) also included in the force generating device  74 , wherein bolt shaft  194  and sleeve  198  of this bolt assembly securely span both guide slots  152  and the bolt hole  204  of the compression block  186 . Also pivotally secured to the bolt shaft  194  and the sleeve  198  is a first end portion  208  (via bolt holes  212 ) of the handle link  76 , wherein the opposite end  220  of the handle link pivotally attaches to the deck  54  as will be described hereinbelow. As can be seen in FIG. 1, side flanges  226  and the cross member  230  of the handle link  76  fit over the lower portion  160 .  
         [0029]    Regarding the opposite end  220  of the handle link  76 , this end is pivotally secured to the deck  54 , and when the angular orientation between the handle apparatus  64  and the deck  54  changes, each end  208  and  220  of the handle link  76  pivots in a manner such that bolt assembly  190  changes position in the guide slots  152 . Thus, when the angle between the handle  68  and any horizontal surface of the deck  54  decreases (e.g., decreases toward 90 degrees), then the bolt assembly  190  is urged toward the upper end of the guide slots  152  and the spring  182  is decompressed. Alternatively, when the angle between the handle  68  and such an horizontal surface increases (e.g., toward 180 degrees), then the bolt assembly  190  is urged toward the lower end of the guide slots  152  and accordingly compresses spring  182 .  
         [0030]    More specifically, the end  220  is pivotally attached to the deck  54  (by pin subassembly  236  having components identified by the same label) within a raised enclosure  244  of the deck. Thus, if during operation the operator changes the angle of the handle apparatus  64  relative to the horizontal, such a change will induce a linear movement of the bolt assembly  190  (and also the spring  182  and compression block  186 ) within the lower portion  160 , and there will be a responsive movement by the handle link  76  which will cause the pressure exerted by the rotating floor care element  62  to at least temporarily change due to a pivoting force of the deck  54  about the axle  120 . Conversely, if during operation the deck  54  is moved, e.g., over a portion of the floor  58  that abruptly rises or falls, then the deck  54  is likely to pivot about the axle  120 , and there will be a corresponding responsive pivoting of the handle link  76  on the pin subassembly  236  and a repositioning of the handle link end  208  along the axis  118  which will, in turn, induce movement in the bolt assembly  190  (and also the spring  182  and compression block  186 ) within the lower portion  160 . Note that induced responses in the deck  54  to movement in the handle apparatus  64  (or visa versa) are dampened depending on, e.g., the compression and resiliency characteristics of the spring  182 . For example, a spring  182  requiring very high forces for compressing will cause the handle link  54  to move more similarly to having its end  208  remain in a constant pivot position along the axis  118  and thus any angular change (relative to the horizontal) between the handle apparatus  64  and the deck  54  will be substantially fully communicated between these two assemblies. However, if spring  182  requires very small forces for compression, then an angular change (relative to the horizontal) between the handle apparatus  64  and the deck  54  will for the most part not be communicated from one of these two assemblies to the other. Accordingly, by adjusting compression characteristics of the spring  182  (e.g., by expanding or decreasing its range of movement within the chamber  136 ), or replacing the spring with a different spring, the responsiveness of the floor care machine  50  to angular changes between the handle apparatus  64  and the deck  54  can be changed.  
         [0031]    Substantially within the confines of the raised enclosure  244  there is also a collection of components that function as a latch mechanism for latching the handle apparatus  64  into a substantially vertical position for storing the floor care machine when not in use (e.g., inactivated). The collection of components for the latch mechanism includes a torsion spring  254  (FIG. 3) disposed on the pin subassembly  236  for biasing the handle link  76  (and accordingly, the handle  68 ) to pivot clockwise (in the orientation of FIG. 2) about this pin subassembly toward a position for operating the floor care machine  50  rather than storing it. Accordingly, when storing the floor care machine  50 , the handle apparatus  64  is rotated to a substantially vertical position by overcoming the bias of the torsion spring  254  and causing the latching mechanism to secure the handle apparatus  64  in the substantially vertical position. Additionally the collection of components for the latch mechanism includes a latch  258  (FIG. 3) pivotally provided on the pin subassembly  236  and within the raised enclosure  244  for receiving a latch striker  262  provided on the end of the handle apparatus  64  opposite from the grip  66 . Note that the latch  258  and the latch striker  262  cooperate to secure the handle apparatus  64  in a substantially vertical position for storing the floor care machine  50 .  
         [0032]    In operation of at least one embodiment of the floor care machine  50 , the wheels  110  are positioned at a level slightly above the level of the floor care element  62 . In one embodiment, the wheels  110  are in the range of ½ to ¾ of an inch above the level of wheels  108 . Moreover, the force system  72  may induce pivoting forces at the axle  120  that: (a) are counter pivot forces to the gravitational and floor suction forces which the deck  54  exerts about the axle  120 , and (b) reduce the possibility of (or the degree to which) the floor care element  62  unevenly or differently contacts the floor when, e.g., undulations in the floor  58  are encountered, and/or different handle apparatus  64  orientations are used by different floor care machine operators. Thus, regarding different operators, for a tall operator having the handle apparatus  64  at substantially a constant 50 degrees, and for a short operator having the handle apparatus  64  at substantially a constant 35 degrees, both operators can cause the floor care element  62  to exert substantially the same pressure on the floor  58  during operation of the floor care machine  50 . However, in order for the force system  72  to achieve the advantages of (a) and (b) immediately above, the spring  182  (or other compressible component) must be matched to the weight and suction forces generated by the deck  54 . In general, for many springs  182  there is a non-trivial range of angles relative to the horizontal wherein there is only a slight variation in the linear force generated by the spring  182 . For example, such a range can correspond to the handle apparatus  64  varying between 35 degrees to 50 degrees from horizontal (i.e., counter clockwise in FIG. 2). However, beyond such a range, the linear force generated by the spring  182  may commence to vary noticeably, and such variation can be beneficial in that an operator can then explicitly cause the floor care element  62  to vary its pressure on the floor  58  to correspond to different floor conditions such as, e.g., exceptionally soiled areas of the floor  58 .  
         [0033]    After transporting the floor care machine  50  from storage to the floor  58  location for which care is desired, the latch striker  262  is disengaged from the latch  258  allowing handle apparatus  64 , including handle  68  and the force generating portions  74 , such as the compression spring  182 , to be pivotal with respect to the deck  54  about pivot pin subassembly  236  and axle  120 . It can then be appreciated that torsion spring  254  biases the handle apparatus  64  from a substantially vertical position and towards an angled position (e.g., 45 degrees) with respect to horizontal. When the handle apparatus  64  is lowered into its operating position as shown in FIG. 2, handle apparatus  64  creates a load on the spring  182 . This load or force translates into a clockwise pivot force on the wheels  108  (in the orientation of FIG. 2) so that there is a downward force to the rear of platform  82  which, in turn, causes an upward lift to the front of platform  82 .  
         [0034]    It should also be appreciated that without activation of motor  90  rotating floor care element  62  and with handle apparatus  64  in an operating position, deck  54  will pivot about wheels  108  such that the forward portion of deck  54  and of floor care element  62  is raised above the floor  58  since there is no floor suction force being provided at the front of the floor care machine  50 . Moreover, an operator can then tilt the floor care machine  50  back so that it can be moved on both sets of wheels  108  and  110  between, e.g., different floor areas and/or to/from storage.  
         [0035]    It can now be appreciated that the wheels  110  of the floor care machine  50  perform a dual function. First, they limit the amount of upward movement of the front of floor care element  62  under the bias of the force generating portions  74  and thus insure that a partial vacuum is created when floor care element  62  is initially rotated to create the suction effect for pulling the front of floor care element  62  downward. Secondly, the wheels  110  serve as transport wheels when floor care machine  50  is being moved between locations.  
         [0036]    Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.