Abstract:
A swing arm for managing a power cord to an electric vehicle has a proximate arm member with a pivotable connection about a vertical axis for connection to the vehicle in proximity to a longitudinal center line of the vehicle. A distal arm member is pivotably connected about a pivot vertical axis to the proximate arm member and resiliently biased to extend straight out with respect to the proximate arm member. The swing arm is dimensioned to extend the distal arm member beyond a side of the vehicle when the swing arm extends laterally with respect to the vehicle. A spring member is connected to the distal arm member for resiliently biasing the distal arm member to extend straight out with respect to the proximate arm member against a side force below a predetermined amount and yieldable to bending of the distal arm member upon exertion of a side force above the predetermined amount.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of pending PCT/US2008/000677 filed on Jan. 18, 2008. 
    
    
     TECHNICAL FIELD 
     The field of this invention relates to a riding apparatus for treating a floor surface with a power cord handling swing arm. 
     BACKGROUND OF THE DISCLOSURE 
     Concrete floors are common today in large, medium and small retail stores, manufacturing and production facilities, warehouses, automotive shops and service centers, shopping centers, garages, commercial buildings and residential basements as well as the common material for sidewalks. The strength of concrete provides the durability and rigidity required in these environments. However, the exterior surface of a newly poured concrete floor, once dry, is often rough, uneven, and provides a dull appearance. Furthermore, when left in this unfinished state, the concrete will inherently produce dust particles from the constant scuffing, whether it is from foot traffic or wheeled traffic that can build over time and become a nuisance to those who work and/or live in these environments. It is well known to first grind the concrete surface and then coat the surface with a sealant to smooth the concrete, to make it aesthetically pleasing to the eye, and to help reduce dust particles. 
     In the grinding process, commonly used grinding machines usually have a planetary or direct drive belt and gear drive systems containing a plurality of circular drive plates mounted to gears on a deck with removable abrasive pads attached to each drive plate. These grinding machines may also be referred to as grinding, honing, abrasive or abrading machines. They may also be referred to as polishing and cleaning machines. Hereinafter, the term “polishing and cleaning” is used in the generic sense and includes abrasion, scrubbing, sweeping, honing, grinding, sanding and/or abrading, cleaning and polishing. These types of machines can also be referred to as an apparatus for treating a floor surface. The term “treating a floor surface” as used herein can mean cleaning, abrading, sanding, scrubbing, sweeping, polishing, grinding or honing a floor surface. These polishing and cleaning machines may typically be electric walk along machines where an operator stands behind the machine and pushes it along at a certain pace such that the deck sufficiently grinds, abrades, hones, polishes and or cleans the floor surface. These walk along configurations can produce fatigue in the operator and the operator&#39;s position behind the machine prevents a clear view of the floor surface until the floor surface passes under the operator&#39;s feet well behind the deck. Thus if a spot on the floor is missed or not adequately prepared, the operator may need to back up a distance to redo the spot. 
     Riding polishing and cleaning machines are known but have had certain drawbacks. Firstly, some are large using standard tractor bodies powered by internal combustion gas, diesel or propane engines. The exhaust from such gasoline, diesel or propane engines makes it less desirable to use within an interior confined space. The use of internal combustion engines and hydraulic drive systems also introduces the significant probability that there may be leakage of oil, petroleum based or synthetic based lubricant or fluid onto a porous cured top layer of concrete or an even more porous substrate. Any leakage or spillage of oil, gasoline diesel fuel or grease onto the surface will be readily and permanently absorbed into the concrete and leave a permanent stain that will never yield a proper polished surface free of stains. Furthermore the oil, grease, or lubricant can contaminate the cutters or other grinding, and polishing pads or tools. 
     In addition, many of these machines are quite large and the operator has no view or a poor view of the floor after the deck passes over. Thus on-the-spot quality control for just prepared floor surface is extremely difficult. 
     Riding polishing and cleaning machines have had awkward configurations with either rear positioned seating or enclosed cab seating for the operator which blocks his view. Other machines have open high precarious seating which can make the operator feel vulnerable or unsafe in such a high open position from the floor. 
     Electric powered riding polishing and cleaning machines are also commercially utilized. While the wheels and vehicular controls are powered by on board rechargeable batteries, the proper high pressure, torque and speed power needed for the cleaning and abrasive deck is too demanding for present day battery technology so the electric power is provided through a power cord from a remote power supply. The power cord often intrudes in the way of the apparatus wheels and deck particularly when the ride on machine is heading in the direction back toward the power supply. A significant amount of time is spent by the operator manually getting off the vehicle to move the cord out of the way of the vehicle. 
     Another difficulty with the known riding polishing and cleaning machines is the difficulty in changing the grit pads or cutters when the grit pads or cutters become worn. Replacing the worn pads or cutters, or in some cases replacing the entire deck is both burdensome and time consuming to the user. 
     Another common problem is dust control. Often the vacuum system at the deck picks up only about 80 percent of the generated dust. The remaining dust must be picked up by a sweeping deck. Previous sweeping decks have been an integral part of the ride-on apparatus&#39;s chassis. As such when uneven flooring or an obstacle is encountered, the sweeping apparatus can be jammed or not provide the necessary ground clearance. 
     What is needed is a riding polishing and cleaning apparatus that allows an operator a relatively low seating position and have direct view of the floor surface behind the cleaning and abrasive deck. What is also needed is a riding polishing and cleaning apparatus that has a power cord handling system. What is also needed is a riding polishing and cleaning apparatus that has a sweeping deck that is vertically adjustable with respect to the apparatus chassis. What is also needed is a riding polishing and cleaning apparatus that has an easily liftable, tillable and disengageable polishing and cleaning deck. 
     SUMMARY OF THE DISCLOSURE 
     In accordance with one aspect of the invention, a riding apparatus for treating a floor surface has a main motorized vehicle with steering and drive wheels and a forwardly located seat for an operator and left and right foot rests for feet of the operator. A polishing and cleaning deck is mounted in front of the vehicle and is operably connected thereto to be moved thereby with a clearance formed between a front of the main motorized vehicle and a rear of the polishing and cleaning deck. The left and right foot rests are spaced apart to form a gap therebetween with the gap and the clearance aligned with the seat located for providing a line of sight for the operator through the gap and clearance to see the floor surface between the polishing and cleaning deck and the main motorized vehicle. 
     Preferably, the vehicle has a low profile rear body section positioned to have its upper surface located below the normal eye level of the operator when seated on the seat such that a full 360 degrees field of vision to the rear is directly available to an operator. The upper surface of the vehicle body is desirable sloped downwardly from a position immediately behind the seat to a rear end of the riding apparatus. 
     According to another aspect of the invention, an upper positioned swing arm is pivotably connected about a substantially vertical pivot axis point behind and above the operator seat and constructed to horizontally swing to the left and to the right of a rearwardly extending position down a center line of the main motorized vehicle. The swing arm has a length more than one-half the width of the vehicle such that the swing arm has sufficient length to extend the restrained section of the cord beyond a left and right side of the vehicle when swinging to its full left or right position. The power cord has a restrained section near a distal end of the swing arm and operably connected to the polishing and cleaning decks for transferring electric power to the deck. Preferably, the pivot is constructed to provide the swing arm to swing approximately 90 degrees to either side of the centered rearwardly extending position. 
     In one embodiment, the vehicle has two front wheels and a rear wheel. The rear wheel is steerable and operably connected to an electric motor for driving the vehicle. The electric motor is powered by an on-board battery source that is directly and continuously rechargeable via the main onboard power supply when powered on and during vehicle operation. 
     It is desirable that the polishing and cleaning deck is pivotably connected along a generally horizontal laterally extending axis to the vehicle through a front distal end of a raisable link arm such that the deck can be pivoted to a generally vertical position to expose the underside of the deck when the deck is in a raised position off of the floor surface. Preferably the link arm has a notch at a distal end and a closable latch for being movable between a closed position to retain the deck to be pivotably mounted to the link arm and an open position to allow the link arm to vertically move to disengage from the deck when in its lower floor engaging position. 
     According to another aspect of the invention, a riding apparatus for treating a floor surface has a sweeping deck mounted under the vehicle behind the polishing and cleaning deck through a linkage that provides relative vertical movement with respect to the vehicle. The sweeping deck includes a motorized brush for sweeping a floor, a hopper for receiving dust from the brush and a castor wheel for providing a lower stop for the sweeping deck. Preferably, a vacuum system is operably connected to collect dust from both the polishing and cleaning deck and the hopper in the sweeping deck. 
     The linkage system includes a lifting actuator to raise the sweeping deck and when in a floor engaging position allows the sweeping deck to automatically lift, i.e. float upwardly, with respect to the vehicle body when encountering a raised floor surface or obstacle under the vehicle body wheels to prevent the sweep deck from jamming the roller brush. 
     In accordance with another aspect of the invention, a power cord handling system for a riding apparatus with a polishing and cleaning deck for treating a floor surface powered from a power cord includes an upper positioned swing arm pivotably connected to the riding apparatus about a substantially vertical pivot axis to horizontally swing the swing arm to the left and to the right of a rearwardly extending position when a torque is exerted thereon. The power cord has a restrained section near a distal end of the swing arm and operably connected for providing electric power to the polishing and cleaning deck. The swing arm has a length more than one-half the width of the vehicle such that the swing arm has sufficient length to extend beyond a left and right side of the riding apparatus when swinging to its full left or right position to position the restrained section of the power cord beyond the respective left and right side of the vehicle. A stop mechanism prevents the swing arm from further horizontal rotation beyond its full left and full right position. A remote power cord reel assembly allows the power cord to be unreeled therefrom when the riding apparatus is moving away from the reel assembly and constructed to substantially take up slack of the power cord when the riding apparatus is moving toward the reel assembly. 
     Preferably the reel assembly having a spring loaded rotatable reel and a weighted frame to stabilize against horizontal torque force exerted by the spring loaded reel. 
     In accordance with another aspect of the invention, an electric powered riding apparatus for treating a floor surface has a motorized vehicle and a power cord extendable from the apparatus to an electric source. A jointed swing arm has a proximate arm member pivotably connected about a vertical axis to the vehicle in proximity to a longitudinal center line of the vehicle. A distal arm member is pivotably connected about a pivot vertical axis to the proximate arm section and has a retainer for mounting the power cord. The distal arm member is resiliently biased to extend straight out with respect to the proximate arm member. 
     The swing arm is dimensioned to extend the distal arm section beyond a side of the vehicle when the swing arm extends laterally with respect to the vehicle. A spring member is connected to the distal arm member for resiliently biasing the distal arm member to extend straight out with respect to the proximate arm member against a side force below a predetermined amount and yieldable to allow bending of the distal member with a side force above the predetermined amount. 
     Preferably, the swing arm is dimensioned to extend at least from its pivotable connection to the vehicle to a rear corner of the vehicle. The proximate arm member has a length no more than one-half the width of the vehicle such that the pivot vertical axis is always within the side extent of the vehicle. 
     In one embodiment, the spring member having sufficient force to maintain the distal arm member straight with respect to the proximate arm member against normal drag forces exerted by the power cord on the floor surface and able to resiliently bend upon the distal arm member abutting against a building support column. The proximate arm member and distal arm member have a mechanical stop therebetween which stops the bending of the distal arm member at approximately 90 degrees with respect to the proximate arm member. The distal arm member has a raised arm section that overlays the proximate arm member. The raised arm section is connected to the spring member. The spring member has an opposite end connected to the proximate arm member. The spring member is preferably in the form of a gas spring having a tubular cylinder member and rod extending from the tubular cylinder member. The distal end of the distal arm member may have at least one roller member pivotably attached about a vertically oriented pivot axis. 
     According to another aspect of the invention, a swing arm for managing a power cord to an electric vehicle has a proximate arm member with a pivotable connection about a vertical axis for connection to the vehicle in proximity to a longitudinal center line of the vehicle. A distal arm member is pivotably connected about a pivot vertical axis to the proximate arm member and is resiliently biased to extend straight out with respect to the proximate arm member. The swing arm is dimensioned to extend the distal arm member beyond a side of the vehicle when the swing arm extends laterally with respect to the vehicle. A spring member is connected to the distal arm member for resiliently biasing the distal arm member to extend straight out with respect to the proximate arm member against a side force below a predetermined amount and yieldable to bending of the distal arm member upon exertion of a side force above the predetermined amount. 
     In accordance with another aspect of the invention, an electric vehicle has a power cord extendable from the vehicle to an electric source. A swing arm has a length extending a least one-half of the width of the vehicle to extend beyond a selected one of the left and right side of the vehicle when swung to a respective full left and right position from a rearwardly extending center position about a substantially vertical pivot axis point. The swing arm has a connection for retaining the power cord near a distal end of the swing arm. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference now is made to the accompanying drawings in which: 
         FIG. 1  is a top perspective view showing a riding apparatus for treating a floor surface according to one embodiment of the invention with a vehicle panel removed to expose the interior; 
         FIG. 2  is an enlarged fragmentary view with the deck shell removed illustrating the polishing and cleaning deck and its mounting frame shown in  FIG. 1 ; 
         FIG. 3  is a top plan view of the riding apparatus shown in  FIG. 1  with the deck shell and vehicle panels removed to show the interior components; 
         FIG. 4  is a fragmentary bottom perspective view of the polishing and cleaning deck illustrating the vacuum hose intakes; 
         FIG. 5  is a side elevational view of the riding apparatus illustrating a person&#39;s field of vision and the lifting and tilting of the front deck to expose the underside of the polishing and cleaning deck; 
         FIG. 6  is an enlarged side elevational view illustrating the polishing and cleaning deck&#39;s connecting linkage to the main vehicle body of the riding sander; 
         FIG. 7  is a fragmentary side elevational view of the floating sweeping deck under the main vehicle body; 
         FIG. 8  is an enlarged elevational view from the other side of the sweeping deck; 
         FIG. 9  is a fragmentary top plan view illustrating an optional edge grinder and polisher attached to the polishing and cleaning deck; 
         FIG. 10  is a side elevational view illustrating the power cord connection to a take up reel and power source; 
         FIG. 11  is an enlarged side elevational view of the power cord reel shown in  FIG. 10 ; 
         FIG. 12  is a top plan view schematically illustrating the position and motion of the riding apparatus and the swing arm during typical back and forth use of the riding apparatus; 
         FIG. 13  is a schematic side elevational view of a riding apparatus with a second embodiment of a swing arm; 
         FIG. 14  is an enlarged top plan view of the swing arm shown in  FIG. 13 ; 
         FIG. 15  is a side elevational view of the swing arm shown in  FIG. 14 ; 
         FIG. 16  is a top plan view of the proximate arm member shown in  FIG. 14 ; 
         FIG. 17  is a top plan view of the distal arm member shown in  FIG. 14 ; 
         FIG. 18  is a top plan view showing the distal arm member being pivoted to a 90 degree angle with respect to the proximate arm member; 
         FIG. 19  is a top plan view of a third embodiment of a swing arm having three rollers on the distal arm member; 
         FIG. 20  is a schematic top plan view of the riding apparatus shown in  FIG. 13  moving in a forward direction; 
         FIG. 21  is a schematic top plan view of the riding apparatus shown in  FIG. 20  moving in a rearward direction and angled to change its floor line; 
         FIG. 22  is a schematic top plan view of the riding apparatus shown in  FIG. 21  after it has moved to its new floor line and moving in a reverse direction; 
         FIG. 23  is a view similar to  FIG. 22  where the swing arm commences abutment with a building column and the distal arm member begins to pivot toward the front of the vehicle as the vehicle moves rearwardly; and 
         FIG. 24  is a view similar to  FIG. 23  showing the distal arm member fully pivoted to a 90 degree position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIG. 1 , a riding apparatus  10  for treating floor surfaces has a battery operated main vehicle body  12 , a forwardly positioned polishing and cleaning deck  14 , a sweeping deck  16 , and a swing arm  18  for a power cord  20 . 
     The vehicle body  12  has a forward positioned operator seat  22  with controls  24  readily positioned for hand operation to control speed, direction and other needed vehicle and deck functions and foot controls  26 , for example a brake and transmission clutch. The seat  22  is positioned over the electric batteries storage container  27 . The electric batteries  31  stored in container  27  as shown in  FIG. 3  can be conventional lead acid type or any state of the art battery that powers the vehicle motion. The seat  22  is also aligned above an axis  29  defined by the two front wheels  28 . 
     Two foot rests  30  are positioned apart to rest the operator&#39;s left and right feet. A gap  32  is formed between the two foot rests  30 . The gap  32  is aligned over the clearance  37  between the center section of the polishing and cleaning deck  14  and the main vehicle body  12  to provide a line of sight to the floor surface. Side vented windows  33  to the inside of the front wheels  28  also provide a line of sight to the floor surface behind the left and right side sections of the front deck  14 . The side vented windows  33  have a support grate  35  that can be used as a single step for an operator  62  to access seat  22 . 
     As shown more clearly in  FIGS. 2 ,  3 , and  4 , three cleaning and abrasive heads  36  that are operated by electric motors  38  are housed within shell  34 . The electric heads  38  are powered from a remote power source delivered through a power cord as described later. The heads  36  are mounted to a deck frame  40 . The deck frame has a horizontally disposed round bar  42  which engages an operable claw end  44  of two parallel arms  46 . 
     As shown in  FIG. 5 , the arms  46  are operated and powered to move between a lower operating position and raised service position to lower the deck  14  onto the floor surface and also to raise the deck  14 . The arms  46  may be power operated for example by hydraulic cylinders  48  through a linkage  49  between the raised and lower positions as shown in  FIG. 6 . In addition, the hydraulic cylinder  48  can provide extra force in the lower position to add some of the weight of the vehicle  12  onto the deck  14  when more downward force is needed during the more aggressive grinding and abrasive operation of the deck  14 . For example, the cylinders  48  can lift the front wheels  28  off of the floor to add the weight to the deck  14 . It is foreseen that hydraulic cylinder  48  can be replaced by other types of power mechanisms, such as electrically driven devices. This use of downward force from the main vehicle eliminates the need of external weight and its associated cumbersome carrying, storing and handling. 
     Furthermore the frame  40  can pivot within the claw end  44  to pivot to deck  14  to a service position shown in  FIG. 5  to expose the disc pad under each head and access the underside of all the disc heads  36 . A removable handle  50  may engage a horizontal grip tube  51  so that an operator can manually pivot the deck  14 . One of several types of locking devices may be engaged to keep the deck  14  in this servicing position. It is noted that the use of the single lever  50  rotates the entire deck including all three heads  36  in one pivoting motion. The deck is raised sufficiently high to assure that the side heads  36  also clear the floor during this pivoting motion. Optionally, the round tube  42  may have a cam lever thereon to be operated by a hydraulic cylinder or linear actuator for power pivoting of the deck. A linear actuator when used can double as a lock due to its worm gear ratio inherently designed therein. 
     As shown in  FIG. 6 , the deck  14  can be disengaged from the vehicle and arms  46  by opening of the claw end  44 , further lowering of the arms  46  to clear the claw end  44  from the round bar  42  and moving the vehicle  12  rearwardly to leave the deck  14  on the floor. Before the vehicle rearward movement, the flexible central vacuum hose  52  can be disconnected as well as any quick connect wiring plugs that provide the power to the electric motors  38 . Reversing the process, reattaches the claw end  44  with the bar  42 . The claw end  44  can be retained in the closed position by a standard lock mechanism for example a clevis pin and retaining hairpin style clip. Alternatively, the claw end  44  opening and closing can be automated and further expedited for example by use of a pneumatic cylinder, electric linear actuator or a remotely operated manual linkage. In this way, the vehicle  12  quickly and can easily switch decks  14  when desired i.e. when decks have different grit pads  70  thereon or switching from a grinding and/or polishing deck to a cleaning deck. In other words, a second deck  14  may be on the floor surface ready to be engaged with the main motorized vehicle  12  after the first deck  14  is disengaged. 
     The round bar  42  is positioned by locating it at or near the fore and aft center of gravity of the deck  14 . The round nature of the bar  42  also allows the deck  14  to pivot thereabout to automatically become horizontal. The front claw  44  provides sufficient clearance for the bar  42  to rotate therein when the claw is in the closed and locked position. As shown with the three heads  36  as positioned, the bar is behind the electric motor  38  of the center head and slightly in front of the electric motors  38  of the left and right heads  36  to achieve the center of gravity balance. 
     The hydraulically operated arms  46  are operated by hydraulic cylinder  48  through linkage  49  that pivots the arms  46  about a rear connection bar  68  which lifts the entire deck  14  including the round bar  42 , all the heads  36 , and frame  40 . Furthermore as shown, easy access to abrasive pads or cutters  70  may be further enhanced by pivoting of the deck about round bar  42  to place the operating underside  72  of the deck  14  in a forward direction. The easy accessibility allows for ease in changing the pads  70  when needed. 
     Referring to  FIG. 4 , the central vacuum hose  52  is connected to a vacuum manifold  54 . Vacuum hoses  56  connect the central manifold  54  to two similar side manifolds  58 . The manifolds  54  and  58  connect to the respective heads  36 . The central vacuum hose  52  leads to the vacuum system to the rear of the operator as described later. The vacuum manifolds  52  and  58  are in communication with the interior of heads  36  through apertures  57 . 
     As shown in  FIG. 5 , an operator  62  is seated in a forward position at the front end of the vehicle  12  and behind the deck  14 . The vehicle is constructed to provide a greatly enhanced view of the floor surface by operator  62 . Firstly, by being up front, the operator  62  has a much better angle to see the floor surface just before it goes under the deck as indicated at  59 . Secondly, the clearance  37  between the rear of the deck  14  and the front of the vehicle  12  and the gap  32  between the foot rests  30  allow for visual viewing of the floor surface after the deck passes over behind the center abrasive head  36  to the area  59  of the floor. Thirdly, the windows  33  allow the operator  62  a line of sight to each area  61  of the floor behind the other two side heads  36  inside of wheels  28 . This visibility just behind all three heads provide real time monitoring of the floor surface and any defects that are discovered can be immediately corrected. To aid in illuminating the floor, optional lights, such as lamps  65  and others (not shown) may be installed on and under the vehicle and aimed to these floor areas  55 ,  59  and  61 . 
     In addition, the low profile of the body  12  well below the operator&#39;s head allows for rear visibility without the need of mirrors to facilitate good vision at the corners during turns and also during rearward motion when necessary. The low profile of the entire vehicle  12  provides for the seat  22  to be relatively close to the floor but still provide a commanding view fully about the vehicle. Furthermore, the low profile provides a security measure and a feeling of safety for the operator  62  as compared to high open cockpit positions found in the prior art. For example, it is feasible to obtain the seat cushion to be 35″ to 45″ high off of floor. 
     As shown in  FIG. 5 , the vehicle has a single rear wheel assembly  80  that is both powered and steerable to maneuver the vehicle  12 . The use of joystick  82  on the front control panel  24  can be used to steer the rear wheel. Alternatively a conventional steering wheel can also be used. One suitable drive wheel is sold under the Metalrota trademark and can give 180 degree steering or turning capability i.e. 90 degrees in each direction. 
     Dust control is accomplished by several separate systems. The first vacuum system picks up dust inside the bowls of grinder heads  36  through the apertures  57  as shown in  FIG. 4  and through hoses  54  and  52  which are operably connected to an inlet  63  of first stage centrifugal separator  64  shown in  FIG. 3  which functions as a pre-cleaner that spins the heaviest solids into a disposable bag lined container  66 . The outlet of the centrifugal separator is drawn into a four stage vacuum motor  68  whose outlet  74  is connected to an envelope filter bag  76  which filters the remaining smaller particles before the air is expelled out through the filter media to the ambient atmosphere. The filter bag  76  has filter media therein which can be cleaned by a backflush system for reversing air flow in a forceful and pulsing fashion to unplug or clean the filter media. This can be accomplished for example by an electrically driven air pump pressurizing an accumulator tank. A dump valve electrically is coupled to a 5 or 6 position switching valve which can be plumbed to the individual bag type filter media. A timer is used to time the dump valve or a pressure switch is used to empty the accumulator tank. 
     A second dust controller includes a sweeping deck  16  suspended under the vehicle  12 . As shown more clearly in  FIGS. 7 and 8 , the sweeping deck  16  includes a frame  84  that is suspended via cables  86  or parallel rods to the vehicle  12 . A hopper  88  is mounted under the frame and has an open side  89  facing a powered roller brush  90 . The hopper  88  is also connected to the vacuum system to evacuate the dust therein to the vacuum system as described above and maintain the hopper in a condition for receiving more dust from the roller brush. The size of the hopper can thus be significantly reduced to an amount correlated with higher CFM (Cubic Feet per Minute) rated vacuums. The roller brush  90  is powered by a motor  92  mounted to the broom arm  94  and belt driven thereby. The broom arm  94  is pivotably adjustable through a wear adjustment knob  96  to maintain proper contact of the brush to the floor as the bush wears and its diameter decreases as shown in phantom in  FIG. 8 . The open side  89  may be closed by a door panel  91  when the apparatus is wet scrubbing to prevent wet slurry from entering the hopper  88 . 
     The entire sweeping deck can be lifted by an actuator  98  that is connected to the frame  84  through a non rigid cable  100 . The non rigid connection allows the rear caster  102  to act as a stop. The non rigid cable  100  prevents the actuator from overloading the casters or the deck would fail to be in the proper position to the floor. In addition should a collision object be encountered by the sweeping deck, the non rigid link  100  allows the entire sweep deck to float over the collision object and thereby minimize damage. Alternatively, the non rigid cable  100  may be replaced by a rigid linkage that is connected via a vertical oriented slot that allows relative vertical movement between the linkage and either the actuator or the sweeping deck  16  to accomplish the same effect. Furthermore, the sweeping deck  16  if damaged can be easily removed from the existing machined for ease of service without disabling the remainder of the vehicle  12 . A replacement sweeping deck can be easily substituted for a damaged one if necessary. 
     Dust wipers (e.g. elastomeric squeegees or brushes)  105  are mounted in front of each front wheel  28  to direct dust inwardly to the inside track of the front wheels  28 . Thus the wheels  28  track through less dust and the dust is directed toward the sweeping deck and roller brush  90 . The wipers may be mounted approximately 45 degrees away from the line of travel to redirect the dust inwardly. 
     A rear seal assembly  104  includes a recirculation flap  106  and a rear flap  108  both mounted to a hook frame  110 . The rear seal assembly  104  can then be suspended behind the sweeping deck and engaged onto a hanger hook  112  on the sub frame  84  which temporarily holds the rear seal assembly  104  in place until two retaining bolts or pins (not shown) are installed which secure the rear seal assembly  104  in its engaged position. The subassembly  104  can thus be easily removed and installed and the removed assembly  104  can be worked on away from the vehicle  12  in a convenient location rather than under the vehicle. 
     An optional edge grinder as shown in  FIG. 9  can further increase the efficiency of the riding sander. The edge grinder attachment  114  is spring loaded through torsion spring  116  off of the deck  14  to be 100 percent retracted upon impact along a wall  118 . Upon contact with the wall  118 , the edge grinder retracts the necessary amount up to 100 percent retraction. The torsion spring allows retraction and recovery to its normal extended position without the need for the operator to stop production to reset anything. 
     The vehicle  12  also stores a clean water tank  120  and a recovery tank  122  at the rear end thereof as illustrated in  FIG. 3 . The clean water tank may either dispense water, a water cleaning solution mix or a densifier solution used during the grinding process. The solution uses gravity through a distribution bar mounted under the sweeping deck frame. The hopper entrance may be blocked and the sweeping brush becomes a rotary paint brush spreading the applied solution. 
     During a sequential grinding pass, the secondary vacuum applied to the hopper is turned off and an independent vacuum attached to the recovery tank is actuated picking up the slurry accumulated at the rear seal  108 . 
     In addition an optional small separate pump can deliver water or water mist into or ahead of the grinding heads  36  to enhance the cutting action and extend the life of the cutters  72 . This water delivery system also provides for the action of wet grinding. A rear squeegee  111  gathers up any remaining slurry and an appropriate positioned vacuum picks up the gathered slurry. This squeegee  111  eliminates the need for a separate wet grinding machine. 
     A power cord handling system is shown in  FIGS. 1 , and  10 - 12 . The power cord is used to deliver power to the electric motors  38  of the heads  36  as well as for recharging the electric batteries  31  used to power the motor to drive the vehicle  12 . The power cord  20  extends from a swing arm  18 . The swing arm  18  is pivotably mounted from an upper central tower or arch  124 . The swing arm normally extends rearwardly as shown in  FIG. 10  when the vehicle is driven away from the power source  126  and a reel assembly  128  as shown in  FIG. 10 . As the vehicle is driven away, the reel rotates as the cord is unrolled therefrom. The reel assembly  128  as shown in  FIG. 11  has a take up reel  130  pivotably mounted on a frame  132  that is weighted by weight base  134  that may have about 175 pounds of weight. The reel is spring loaded to be able to take up approximately 150 feet of power cord that contains four #6 flexible wires inside an abrasion resistant sheath of approximately ⅞″ diameter. The weight is used to stabilize the reel assembly  128  against take up force of the spring against the full 150 feet of cord that produces about a 175 pound horizontal pull without sliding or tipping over. The reel assembly has a feed-in cord  136  from a power source such as an outdoor generator. 
     As shown in  FIG. 12 , as the vehicle  12  moves away from the reel assembly, the swing arm extends rearwardly. As the vehicle  12  turns from the initial direction away from the reel, the swing arm is free to pivot to the side of the vehicle  12  to continue to point toward the reel. The swing arm is allowed to pivot up to approximately 90 degrees to either side as shown when the vehicle  12  is turned moving in a transverse direction. A stop member  137  on top of the arch  124  limits the motion to the 90 degrees such that when the vehicle returns in a direction toward the reel, the swing arm remains at the full left or right position. Furthermore, the reel automatically takes up slack cord as the vehicle  12  moves in a direction toward the reel and allows the power cord to be released as the vehicle moves away from the reel. The swing arm  18  has a dimension sufficiently great to extend beyond the left or right side of the vehicle  12  when it is in the full left or right position. In this manner, the power cord is retained off to the side of the vehicle  12  when the vehicle goes in a direction toward the reel. The positioning of the power cord automatically away from the front of the vehicle  12  provides the continuous operation of the vehicle  12  without the need for an operator to stop operating and manually move the power cord off to the side. 
     The swing arm may be fitted with a sensor so that if the arm sensor sends a torque above a predetermined amount between the two stops  137 , a warning indicator such as a light or an alarm may be sounded to alert the operator that there is an undesirable condition with the reel, power cord or arm. The sensor may also if desired, be coupled to a deactuation device that safely interrupts the power to the main vehicle until the situation causing the excessive torque is eliminated. 
     The reel assembly  128  may also have a wiper  140  positioned to engage and wipe clean the power cord  20  as it is pulled from and reeled back into the reel assembly  128 . This wiper  140  also further reduces the spread of free dust created by the deck  14 . 
     Another method for covering floor surfaces is by using shorter runs and instead of making a u-turn which takes time, the operator merely backs up the riding apparatus and slightly turns to a new lane i.e. new floor line. He then moves forward again and back again in a zigzag fashion. When such a zig-zag motion of the ride-on apparatus is done, a modified swing arm as illustrated in  FIGS. 13-24  is desired. This swing arm  218  retains the power cord  220  via a hook  238 . There is no usage of the reel  128  in this set up. 
     As shown in  FIGS. 13 and 20  when the riding apparatus is travelling in a forward direction and away from the from its cord source, the swing arm  218  is usually pulled to the center and rear of the main vehicle body  12  by the drag resistance of the cord  220 . This places the swing arm  218  within the side confines of the vehicle body  12  as clearly shown in  FIG. 20 . 
     The swing arm  218  has a proximate arm member  222  that is pivotally connected at end  228  to the riding apparatus  10  through a vertical axis. As shown in  FIGS. 14-18 , the swing arm  218  also has a distal arm member  224  that is pivotally connected to the proximate arm member through pivotal connection  230  through both arm members  222  and  224 . This pivot connection  230  is also about the vertical axis. The distal arm member has hook  238  mounted at its distal end and a roller  226  also rotatably connected near the distal end for rolling around vertically oriented pivot axis  227 . While the embodiment shown in  FIG. 14  shows a single roller, other embodiments may have a plurality of rollers such as the embodiment shown in  FIG. 19  that illustrates three rollers. The distal arm has a raised section  240  to provide clearance over the proximate arm  222 . A resilient spring for example in the form of a gas spring member  232  or coil (not shown) is connected to the distal arm at pivot point  234  and to the proximate arm at pivot point  236 . The gas spring  232  normally provides resilient bias to the distal arm member  224  straight on it with respect to the proximate arm member  222 . The spring member  232  provides sufficient resistance to maintain the distal arm member straight against any side forces exerted by dragging of up to 200 feet of power cord along a concrete surface either in the forward direction as shown in  FIG. 20  or in as the vehicle  12  moves in the reverse direction as shown in  FIG. 22 . 
     When a side torque of above a predetermined amount is exerted on the distal arm member  224 , the distal arm can then pivot i.e. yield to the side exerted torque. Such a large side torque may be presented by a building column which may hit the distal arm as the riding apparatus passes. The distal arm member  224  may bend to a position up to 90 degrees as illustrated in  FIG. 18  with respect to proximate arm member  222 . A mechanical stop  242  between the two arm members  222  and  224  prevents the distal arm member  224  from flexing more than 90 degrees as shown in  FIG. 18 . In this position, the gas spring  232  is almost at its full extension with its inner piston rod  238  extending out therefrom. The gas spring  232  in this position provides for a retraction force so that when the side torque is released, the rod  238  retracts again and pulls the distal arm section  224  back to its straight position as illustrated in  FIG. 14 . The connection pivot point  234  of the gas spring is a significant distance from the pivot point  230  of the distal arm member  224  to the proximate arm member  222  to provide for a mechanical advantage of the gas spring and to allow a full 90 degrees of movement of the two arm members  222  and  224  before mechanical contact between the two arm members create a mechanical stop. The geometry also allows the rotation of the distal arm member  224  to go in either direction for a total of 180 degrees of motion with respect to the proximate arm member  222 . 
     The zig-zag motion of the riding apparatus  10  and the side bending of the swing arm can be better illustrated with reference to  FIGS. 20 to 24  as the vehicle encounters a building support column  250 . When the operator ends the forward run and starts to reverse and turns the vehicle to change lanes and do an overlapping run as shown in  FIG. 21 , the drag of the cord  220  riding apparatus  10  then swings the arm  218  sideways. The length of the swing arm  218  is dimensioned to clear either rear corner  244  of the vehicle main body  12 . The operator then straightens out the vehicle still travelling in the reverse direction as shown in  FIG. 22 . In this condition, the swing arm  218  extends sideways and protrudes significantly outside the side confines of the vehicle  12 . 
     Furthermore, the proximate arm member  222  is dimensioned to be wholly within the side confines of the vehicle  12 . The pivot axis  234  is also within the confines of the vehicle  12  at about a midpoint of the sing arm  218 . The side to side overlap action of the vehicle back and forth runs may vary but it is always less than the width of the vehicle width. It is possible that the overlap allows the sideways extending swing arm  218 , particularly the distal arm member  224  to be within reach of a building support column  250  as shown in  FIG. 23 . While the operator is concentrating on making a straight rearward pass as he looks back over his shoulder while steering, he may not pay attention to the reach and position of the swing arm  218 . 
     If and when the distal arm member encounters an obstacle, for example a building support column  250  as shown in  FIG. 23 , it will yield. The gas spring force is low enough to allow such yielding of the distal arm member when it encounters fixed objects such as building columns. The arm can bend up to 90 degrees to be completely within the confines of the vehicle width as shown in  FIG. 24  to allow the vehicle to back up past the building column. Once the building column is cleared, the distal arm member will resiliently pivot back to its extended position as shown in  FIG. 97 . 
     The roller  226  is preferably a rubber style wheel to further minimize any damage that might occur from contact with walls and columns. Furthermore, the rubber wheels are advantageous when the apparatus  10  is near a room corner and the operator needs to reverse to back up out of the corner. The roller  226  rolls down the wall preventing the arm from grabbing and digging into the wall, particularly if the wall is made from soft material, for example dry wall. The embodiment shown in  FIG. 19  illustrating three rollers  226  even further reduces the impact of collision between the column and the arm since most of the impact will be with the rollers  226  that will tend to roll as opposed to only the distal arm what would otherwise drag against the wall or column. 
     Variations and modifications are possible without departing from the scope and spirit of the present invention as defined by the appended claims.