Abstract:
A cleaning machine employing a vertically shiftable brush and motor assembly, a separate vertically shiftable skirt/splash guard assembly, and a cooperative arrangement between the brush and skirt assemblies causing controlled elevation of the skirt with elevation of the brush. Both the skirt and the brush remain in optimum engagement with a floor surface during operation, but the skirt is elevated cooperatively with elevation of the brush using a lost motion engagement.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to floor cleaning machines. Floor cleaning machines, particularly floor scrubbers, typically employ one or more powered rotary scrub brushes suspended beneath the scrubber vehicle, and peripheral skirts or splash guards around the machine periphery for retaining the floor cleaning liquid beneath the vehicle. Heretofore the scrub brushes have been directly mounted to the vehicle frame, or have been vertically movable relative to the vehicle frame. The skirts/splash guards are sometimes mounted to the brush motor or motor support as in FIG. 13, and sometimes are mounted directly to the vehicle frame independent of vertically movable brushes as in FIG.  14 . 
     Disadvantages of the FIG. 13 arrangement include poor appearance of the machine due to exposure of the motor and related mechanism, difficulty in seeing and installing new brushes because of interference by the skirt, and skirt dragging and premature wear of the skirt as the brush bristles wear down. 
     Disadvantages of the FIG. 14 arrangement include the fact that the skirt remains in engagement with the floor when the brush is elevated, and that, on uneven floors, the skirt will at least partially lift enough to allow cleaning fluid to spray out under the splash guard. 
     SUMMARY OF THE INVENTION 
     The present cleaning machine employs a vertically shiftable brush and motor assembly, a separate vertically shiftable skirt/splash guard assembly, and a cooperative arrangement between the brush and skirt causing controlled elevation of the skirt with elevation of the brush. Both the skirt and the brush remain in optimum engagement with a floor surface during operation, but since the skirt is elevated cooperatively with elevation of the brush using a lost motion engagement, the skirt does not drag on the floor when the brush is not scrubbing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of the novel scrubbing machine; 
     FIG. 2 is a front elevational view of the scrubbing machine; 
     FIG. 3 is a bottom view of the scrubbing machine with the scrub brushes depicted by dash lines, and the brush frame and skirt supports shown in detail; 
     FIG. 4 is a top plan view of the brush and motor support frame; 
     FIG. 5 is a side elevational view of the brush and motor support frame; 
     FIG. 6 is an end elevational view of the brush and motor support frame; 
     FIG. 7 is a top plan view of the skirt support frame; 
     FIG. 8 is a side elevational view of the skirt support frame; 
     FIG. 9 is an end elevational view of the skirt support frame; 
     FIG. 10 is a plan view of the left skirt housing; 
     FIG. 11 is a plan view of the right skirt housing; 
     FIG. 12 is a diagrammatic figure of the novel machine; 
     FIG. 13 is a diagrammatic figure of one type of prior art machine with brushes and skirt; 
     FIG. 14 is a diagrammatic figure of another type of prior art machine with brushes and skirt. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, the floor cleaning machine  10  includes a vehicle frame  12  on which the remaining components of the apparatus are mounted. The vehicle frame has floor engagement wheels  14  and  16  mounted on respective axles  14 ′ and  16 ′ supporting the floor cleaning machine and connected to the vehicle frame by two pairs of depending elements  12 ′ and  12 ″. Mounted on the vehicle frame are the typical components, namely a housing  20  enclosing a conventional water containment vessel  22 , waste water vessel  24 , and valve  25  and conduit  25 ′ (FIG. 4) to apply water to the floor surface to be cleaned, as well as suction pumps for subsequently removing the dirty water from the floor surface as the machine passes over it. These housing contained components are standard and form no particular part of this invention and thus, for purposes of maintaining clarity, are not shown or described in detail. 
     Located beneath the vehicle frame is a brush and motor support frame  30  which supports at least one, and preferably a plurality, such as a pair, of scrubber brushes  34  including a brush hub plate  32  and suspended bristles  34 . In the embodiment depicted, the scrub brushes are horizontally rotationally driven brushes, each connected to a rotary electric drive motor  36  by the motor shaft  36 ′. The end of brush frame  30  closest to wheels  14  has upstanding brackets  30   d  movably mounted, preferably by a parallelogram linkage  38  formed of upper and lower links  38   a  and  38   b  to a support element  12   a  of vehicle frame  12  such that the brush frame and brushes can move vertically while maintaining a generally planar horizontal orientation at the floor surface or parallel thereto when elevated. An electric power actuator  44 , or the equivalent, is vertically arranged and has its upper end  44   a  mounted to the vehicle frame and its lower end  44   b  at the lower end of its actuator piston rod attached to brush frame  30  for raising or lowering the brush assembly as controlled by the operator of the floor cleaning machine. The connection of actuator  44  with the brush housing comprises the pin  44   a  at the upper end of actuator  44 . The actuator is attached to the brush frame by a pin  44   b  within a vertical slot  30   c  in bracket  30   b  extending up from brush frame  30 , and connected to piston rod  44   c . Therefore, in the lowered position, the brush frame and brushes are free to follow an uneven floor surface without interference from the actuator  44 . 
     Extending around the brush assembly, and particularly around the rotary brushes, is a floor engagement skirt assembly  50  preferably including a vertical flexible polymeric skirt  52 , the lower edge of which can engage the floor surface F. The primary purpose of this skirt is to retain the cleaning fluid, typically an aqueous liquid, beneath the machine, i.e., from being propelled by the spinning brushes out beyond the confines of the machine. This skirt assembly includes at least one, and preferably two, mirror image skirt housing and assembly supports  54  (FIGS. 3,  10  and  11 ), one on each side of the machine and extending to each other in front of the machine. The two skirt housing assemblies  54  preferably have their forward inner portions attached by vertical pivot pins  55   b  (FIG. 3) to forwardly extending bracket  55   a  on the skirt frame  55 . Each skirt housing assembly can thus be pivotally moved laterally to allow easy access to the brush assembly. The skirt support frame is mounted on a horizontal transverse pivot connection  55   c  to the vehicle frame. Thus, the skirt supports and skirts can be raised or lowered about the pivot axis of this pivot connection  55   c  (FIGS.  3  and  7 ). This is done with a lost motion engagement between the brush frame and the skirt frames. Specifically, the brush frame is provided with a lift element  30   a  shown as a horizontal flange, and the skirt frame  55  is provided with an engageable flange element  54   b  located directly above element  30   a . The lowermost position of the skirt assembly is determined by the engagement of one or more wheels  40  with the floor surface F. The lowermost position of the brush assembly is determined by engagement of the brush bristles  34  with the floor surface F. In this lowered condition of both assemblies, there is a vertical space between elements  30   a  and  54   b . Because of this arrangement, both the brushes and the skirt have optimum continuous engagement with the floor during operation of the machine, even an uneven floor, independent of each other. 
     When the brush assembly is elevated by retraction actuation of power cylinder actuator  44 , engagement element  30   a  on the brush frame will engage engageable element  54   a  of the skirt frame after a certain amount of lost motion between the two, to then elevate the skirt assembly with the brush assembly and thereby move both of them out of engagement with floor surface F. 
     The novel apparatus has several advantages. Specifically, each skirt housing assembly can swing open for easy access to the brushes and motors. The skirts have good wear life because they are not dragged across the surface of the floor when the brushes are not down and actuated. The skirt assemblies can even be quickly removed for transport, or access to the brushes. The skirts are lifted off the floor when the brushes are lifted to inactive condition. The motor and related mechanism are enclosed to contribute to the good appearance of the machine. The front caster provides consistent and excellent contact of the skirt with the floor to contain the cleaning liquid. Yet, in spite of these advantages, the cost of this arrangement is modest and practical. In addition, if desired, side mounted squeegees can be placed on the skirt housing and will lift off the floor when the brushes are lifted. 
     The above description is considered that of the preferred embodiment only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiment shown in the drawings and described above is merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the doctrine of equivalents.