Abstract:
The present invention is a sweeper incorporating multiple rotation elements mounted adjacently in an rotationally offset sequence on a common driven axle. Each rotation element comprises a central shaft support from which extends lightweight extension arms that have laterally elongated spatulate paddles at their ends. The extension arms may be curved so that in operation a terminal edge of each paddle lags the rest of the paddle surface in approaching and sweeping across the floor surface and is quite easily deflected upward from a floor surface.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to rotationally driven sweepers, especially those which are battery operated and whose rotated elements contact a floor surface. 
     Electric-powered sweepers with extensions from a rotating, cylindrical drum are routinely used to sweep dirt particles directly from a floor surface into a closed container while traversing a floor area. The extensions of such sweepers must contact a floor or rug surface and make a brushing impact with that surface with sufficient force to effectively cause the elevation and forceful trajectory of all dirt and waste particles the extension encounters. Substantial electrical power is required in prior art designs to accomplish this function. Well known prior art designs of sweepers and vacuum cleaners mount longitudinal rows of flexible, straight bristles on a cylinder rotated at high speed. The bristle ends must impact upon and sweep a floor surface at high speed. While the bristle structure is beneficial in that fabrication has become inexpensive, the straight bristle design is impractical for battery powered sweepers due to the relatively high power requirements needed to cause bristle rotation and deformation on impact with a floor surface. 
     Although self-contained battery powered electric vacuum cleaners are well known, they can only be used for small area cleaning because they have too little stored power to clean any significant area due to their inherent high power requirements. There is a need for a sweeper design which accomplishes effective sweeping with low power requirements. 
     SUMMARY OF THE INVENTION 
     The present invention is a sweeper design incorporating multiple rotation elements mounted adjacently in an rotationally offset sequence on a common driven axle. Each rotation element comprises a central shaft support from which extends lightweight extension arms that have laterally elongated spatulate paddles at their ends. The extension arms are curved so that in operation a terminal edge of each paddle lags the rest of the paddle surface in approaching and sweeping across the floor surface and is quite easily deflected upward from a floor surface. This angular approach of the paddles to the sweeping surface reduces energy consumption while preserving effective sweeping of the surface. 
     The rotational elements are not longitudinally aligned along their rotation axis. Instead, the arms of the rotational elements are axially staggered apart from one another so that each paddle leads and/or lags a paddle of an adjacent rotation element while in operation. In addition, longitudinal parts of a lagging paddle rotationally overlap at least part of the rotational path of a leading paddle which rotationally leads the lagging paddle. Rotational overlap provides for sweeping impact for a dirt particle on the lagging paddle that may have escaped upward sweeping motion of the leading paddle. 
     In a preferred embodiment, multiple rotation elements are arranged on a rotation support shaft so that the sequence of adjacent rotation elements from each end toward a center of the shaft provides for leading to lagging spatulate paddles 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of an embodiment of the invention sweeper showing rotation elements and internal components in broken lines. 
         FIG. 2  is a side perspective view of a rotation element. 
         FIG. 3  is a side view of a rotation element. 
         FIG. 4  is a front view of a rotation element. 
         FIG. 5  is a side cutaway view of a frontal portion of the sweeper of  FIG. 1 . 
         FIG. 6  is a top cutaway view of a frontal portion of the sweeper of  FIG. 1  without side housings. 
         FIG. 7  is a top cutaway view of a frontal portion of the sweeper of  FIG. 1  with side housings. 
         FIG. 8  is a side cutaway view of the internal housing for rotation elements (not shown) of the device of  FIG. 7 . 
         FIG. 9  is a side cutaway view of the left side housing of the device of  FIG. 7 . 
         FIG. 10  is a side cutaway view of the right side housing of the device of  FIG. 7 . 
         FIGS. 11 ,  12 , and  13  are respectively right, left and front views of a rotation element having three arms. 
         FIG. 14  is a side view of three rotation elements of  FIG. 11  interlocked in a side by side alignment. 
         FIG. 15  is a front view of two of the rotation elements of  FIG. 11  interlocked for rotation about a drive axle. 
         FIGS. 16 ,  17  and  18  are respectively front, top perspective, rear, top perspective and side views of a second embodiment of the invention sweeper. 
         FIG. 19  is a front, cutaway view of a rotation element housing of the sweeper of  FIG. 18 . 
         FIG. 20  is a side, cutaway view of the rotation element housing and waste receptacle housings of the sweeper of  FIG. 18 . 
         FIGS. 21 ,  22 ,  23  and  24  are respectively bottom cutaway, top, front and rear views of a bottom waste receptacle housing. 
         FIGS. 25 ,  26 ,  27 ,  28  and  29  are respectively top, front, side, rear and side cutaway views of a top waste receptacle housing. 
         FIGS. 30 ,  31  and  32  are respectively bottom, front and side views of the assembled top and bottom waste receptacle housings. 
         FIG. 33  is a side view of a compact embodiment of the invention. 
         FIG. 34  is a front view of an over housing of the device of  FIG. 33 . 
         FIGS. 35 and 36  are, respectively, side and front views of enlarged bore sweeper elements for the device of  FIG. 33 . 
         FIG. 37  is an end view of a motor connector cylinder adapted to engage a cylindrical electric motor. 
         FIG. 38  is a side cutaway view of the cylinder of  FIG. 37  where a small electric motor is shown separated from its connected position with said cylinder. 
         FIG. 39  is a front, cutaway view of a battery and controller housing connected by two downward arms to a rotating support for sweeper elements of  FIG. 36  driven by the motor connected with motor connector cylinder of  FIG. 38 . 
         FIG. 40  is a side cutaway view of the device of  FIG. 33  without the battery and controller housing and downward arms of  FIG. 39 . 
         FIG. 41  is a bottom view of the device of  FIG. 33 . 
         FIG. 42  is a top view of the device of  FIG. 33  without the battery and controller housing and at a cross section downward arms of  FIG. 39 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention is now discussed with reference to the figures. 
     The invention sweeper  100  shown in  FIG. 1  comprises rotation elements  101  fixed rotationally relative to each other on drive shaft  110  so that spatulate paddles at the end of extensions  111  are rotated in a counterclockwise manner. The spatulate paddles comprise terminal edges that sweep along the internal cylindrical surface of housing  102  and through the rectangular opening  103  to sweep upon floor  112 . The spatulate paddle in that floor sweeping action impacts upon particle  107  resting on floor  112 , causing it to be lifted and swept up along ramp  104  to be delivered into passage  105  and deposited in receiver cavity  106  along path  108 , where air compressed and swept into the passage  105  is expelled through screened vent  108  while leaving behind particle  107  in cavity  106 . Motor  113  is shown in broken lines connected by belt  114  to wheel  115 . Wheel  115  is in turn connected to drive shaft  110  to cause rotation of drive shaft  110  and thereby rotation of rotation elements  110 . Batteries  116  are shown secured within external housing  118  to power motor  113 . A pivoted handle  117  is shown attached to housing  118  so that sweeper  100  may be moved back and forth along floor  112  to accomplish a sweeping of that surface. 
       FIGS. 2 ,  3  and  4  show rotation element  101  comprising a hub  123  with a bore  124  through which drive shaft  110  is inserted for driving support of element  101 . From hub  123  extend extensions  120 , each comprising a concave side  121  and convex side  122 . At distal and terminal ends of extensions  120  are fixed a spatulate paddle  119  extending laterally to the extensions to form an oval or rectangular sweeping surface with substantially greater lateral sweeping surface area than the convex side  122  of extension  120 . In a preferred embodiment, the spatulate paddle  119  comprises a flat piece with a width of from 5 to 15 millimeters, height of from 2 to 5 millimeters, and a thickness of from 0.1 to 1.0 millimeters. The frontal surface of paddles  119  are shown to be continuous with the convex side  122 , but are substantially wider than the surfaces of convex sides  122 . This structure provides for substantial sweeping surfaces at terminal ends of extensions  120  where the most significant part of sweeping occurs. This structure also reduces the surface area of convex sides  122  and thereby reduces power requirements for their rotation commensurate with their less significant sweeping capability. 
     Hub  123  comprises interlocking lugs  125  which define slot  124 . Adjacent rotation elements  120  have are fitted together so that their lugs  125  and slots  124  cause adjacent rotation elements to be maintained in rotational separation by from about ten degrees to forty five degrees, although more preferably from about fifteen degrees to about thirty degrees. This rotational alignment along drive shaft  110  controls the arc distance between leading and lagging spatulate paddles. Reducing the rotational separation of the rotation elements  120  improves single pass sweeping efficiency at a higher power cost, while increasing that separation reduces the total number of rotational elements at the cost of reducing single pass sweeping efficiency. 
       FIGS. 5 and 6  show side and top cutaway views of a preferred form of the invention sweeper. Increasing or decreasing the number of rotation elements is optional. Rotation elements  130  to  135  are rotationally separated by about over 20 degrees so that, for example, paddle  119   a  rotationally overlaps the rotational path of  119   b  by at least about 1-2 millimeters so that particle  156  can be passed along the ramp  104  ends of elements  130  to  135  to be finally lifted up ramp  104  to passage  105 . Similarly, rotation elements  140  to  135  are rotationally separated by about over 20 degrees so that, for example, their spatulate paddles rotationally overlap those of adjacent spatulate paddles by at least about 1-2 millimeters so that particle  157  can be passed along the ramp  104  ends of elements  140  to  135  to be finally lifted up ramp  104  to passage  105 . The particular orientation of the ramp  104  ends of rotation elements  130  to  140  form a cylindrical V-shape sweeping formation with a lagging vertex at the ramp  104  paddle of element  135 . This sweeping formation provides for successive V-shaped sweeping formations brushing against the inside cylindrical surface of housing  102 , across floor  141  by emerging through opening  103 , brushing up ramp  104 , across the opening of passage  105 , and again into contact with the inside cylindrical surface of housing  102 . It can be appreciated that particle  142  on floor  141  is impacted by the flexed spatulate paddle  119   c , shown as a broken line representation of the unflexed paddle  119  in  FIG. 5 . As paddle  119   a  is rotated up toward ramp  104 , it again straightens after its flexing contact with floor  141 . Particle  142  is lifted and swept up ramp  104  to location  144 , where it is typically lifted up to impact a top part of passage  105  to rebound to location  145 , from whence it is deposited into the receiver cavity  106 . Motor  154  is shown driving pulley wheel  153 , which in turn drives belt  155  to drive pulley wheel  152  and thereby connect to drive shaft  110  at bolted connector  151 . 
       FIGS. 5 and 6  show that providing two extensions with spatulate paddles per each rotation element creates two of the above V-shaped sweeping formations moving along the surfaces of housing  102  and ramp  104  and across opening  103  and the opening of passage  105 . It is well shown that at all times spatulate paddles  119  are at all times substantially angled forward at less than normal to any surface across which they may sweep. The loss of sweeping efficiency by so inclining the spatulate paddles is more than compensated by rotation at a relatively high speed and rotationally overlapping paths. Sweeping efficiency is quite high at a reduced power consumption. Each element  120  preferably has a length of from about 40 to 70 millimeters and a weight of from 1 to 3 grams. A preferred composition is polyolefin polymers such as polyethylene. 
       FIG. 7  shows a top and cutaway view of additional side housings for the wheels  152  and  153  and roller wheels  163  and  164 . Wheels  163  and  164  extend through openings  172  and  174  respectively of housings  158  (defining cavity  106 ) and  159  (defining cavity  161 ). Axles  175  and  165  extend into their associated housings to support wheels  163  and  164  to provide rolling support of the sweeper along a swept floor. A cutaway section  162  shows that motor  154  is secured to an endwall of housing  102  so that its drive shaft  168  ( FIG. 8 ) is rotatable to drive pulley wheel  153 . 
       FIG. 8  shows that housing  102  comprises a substantially cylindrical inside surface at a uniform distance from drive shaft  110  so that spatulate paddles of the rotation elements will lightly brush against said surface. Receiver cavity  106  is defined by a housing  170  supporting a filtered or screened vent  109  to the outside of said housing. Internal extensions of housing  170  provide effective support for drive batteries  116  between walls  169 . Motor  154  is shown secured to and underlying a housing formed underneath ramp  104  with electrical wire  173 . 
       FIG. 9  shows that wire  173  extends to cavity  160  and upward to connect with drive batteries. 
       FIG. 10  shows a connector  150  fixes an end of drive shaft  110  to an endwall of housing  102 . 
       FIGS. 11 through 32  describe an alternate embodiment of the invention sweeper. 
       FIGS. 11 ,  12 , and  13  are respectively right, left and front views of a rotation element  180  having three arms  181 , wherein each arm terminates in spatulate paddle  182  and connected to central connector defining an axle bore  183  and having right side articulations  184  and left side articulations  185  adapted to interlock with each other when elements  180   a  and  180   b  are arranged on a supporting axle, as shown in  FIGS. 14 and 15 . Element  180   c  is shown in  FIG. 14 , thereby defining an operational unit for the sweeper with paddles  182  axially separated by about 30 degrees. Paddles  182  in  FIG. 15  show rotational overlap when said elements rotate. 
       FIGS. 16 ,  17  and  18  are respectively front, top perspective, rear, top perspective and side views of a second embodiment  190  of the invention sweeper. Generally, a front housing  191  supports an axle (not shown) that connects and supports wheels  195  exterior to housing  191  and elements  180  (not shown) in the space  196 . A rear waste receptacle  192  is comprised of top housing  193  and bottom housing  194 . Top housing  193  is connected by hinges  200  to bottom housing  194  at an upper plate  199  of bottom housing  199 . Bottom housing  194  is comprised of a floor  197  and sidewalls  198 , whose upper edges are adapted to mate to lower edges of sidewalls  221  of top housing  193 . Upper plate  199  connects frontal ends of sidewalls  198 .  FIG. 17  shows top housing  193  rotated into an open position for disposal of waste swept into the space defined when the top housing  193  and bottom housing  194  are latched shut by latch  104 , as shown in  FIG. 18 .  FIG. 18  shows that handle  201  (in broken view) connects with front housing  191  at an upper end. Upper housing  191  and receptacle  192  are secured to and are rotatable about axle means  207 , which axle means also secure wheels  195  outside an upper housing  191  so that sweeper  190  can be moved across a swept floor. Interface  202  shows mating and closure edges of top housing  193  and bottom housing  194 , whereby receptacle  192  is in a closed position and can receive and retain waste particles swept into in by action of elements  180 . 
       FIG. 19  is a front, cutaway view of a rotation element housing of the sweeper  190  showing interior structure and operational parts. Side walls  208  extend from a position relatively close to a supporting floor for the sweeper up to a roof  213 , which, with front and rear walls  211 , define an interior space divided by plate  209 . Plate  209  supports rechargeable battery  212  and motor  214 , which are electrically connected via wires  212   a . Battery  212  comprises external access to recharge plug and an on/off switch with which a user may turn motor  214  on or off. Motor  214  comprises an lateral extension through side wall  208  into a space defined between side housing  217  and an outside surface of sidewall  208 , providing protective enclosure for two belt pulley wheels  215  and  216 , where pulley wheel  215  is connected with said extension of motor  214 . Motor  214  is adapted to cause rotation of pulley wheel  215  so that pulley wheel  216  rotates by belt connection thereto. Rotation of pulley wheel  216  causes effective, sweeping rotation of elements  180  (as in  FIGS. 11 ,  12  and  13 ) in space  196  about axle  218  by nature of interlocking connections between said elements  180  and an interlocking connection between an element  180  located adjacent to pulley wheel  216  but separated from it by sidewall  208 . Pulley wheel  216  is aligned for connection via belt (not shown) with pulley wheel  215  and is further connected to axle  218 . Axle  218  extends through and is supported by sidewalls  208  and side housing  217 . 
       FIG. 20  is a side, cutaway view of the front housing  191  and waste receptacle  192 . Sidewall  208  is shown in broken away view showing the alignment of interlocked elements  180  on axle  218 . The lowest most paddles of elements  180 , when rotated, sweep particles off a supporting floor along path  225  into the space defined between top housing  193  and bottom housing  194 . A rubber wedge element  224  is secured to and extends along the width of a bottom, front edge of floor  197  to provide and upward ramp for launching swept up particles into said space between housings  193  and  194 . Upper plate  199  is arranged so that rotating paddles of elements  180  extend close to an under surface thereof in rotating operation. In this cutaway view, top housing  193  is shown comprising sidewalls  221  and top  220 , the rear portions of which are boxed in by end plate  222 , extending down from which is latch  204 . Front plate  218  boxes in front portions of sidewalls  221  and top  220 . Lateral extensions from aspect  219  support hinge means. 
       FIGS. 21 ,  22 ,  23  and  24  are respectively bottom cutaway, top, front and rear views of the bottom housing  194 .  FIG. 21  shows section  227  upon which is secured wedge element  224 . Hole  230  provides support for axle means by which waste receptacle  192  is rotatable with respect to the front housing  191 . Rear edge  229  is adapted to receive a latching engagement with latch  204  ( FIG. 20 ). 
       FIGS. 25 ,  26 ,  27 ,  28  and  29  are respectively top, front, side, rear and side cutaway views of the top housing  193 . Cutout portions of top  220 , sidewalls  221  and end plate  218  provide space for extension of pins  232  to form an axis for rotation of top housing with respect to bottom housing  194 .  FIG. 27  shows edges  234  which are adapted to mate to top edges of sidewalls of the bottom housing when the waste receptacle is in the closed position. Downward extensions  235  are adapted to lie just within said sidewalls of the bottom housing. 
       FIGS. 30 ,  31  and  32  are respectively bottom, front and side views of the assembled top housing  193  and bottom housing  194 .  FIGS. 30 and 32  show top and side views of loop  237  which secures extension  232  to upper plate  199  so that the top housing can be opened and closed by rotation about the axis formed by pins  232 . 
     With the exception of electrical components, the invention sweeper may be formed from low cost polymer components and housings. The invention sweeper will have two or more rotation elements. 
     As shown in  FIGS. 33 through 42 , the following is a description of a compact embodiment of the invention.  FIG. 33  is a side view of a compact embodiment device  300  comprising a hand pushed sweeper with handle  301  (shown in part) connected with battery/controller housing  302 , which extends down via two support arms  333  though slots  363  defined in an upper most part of a front portion  304  of over housing  303 . Over housing  303  is a shell defining an internal cavity generally enclosing rotating sweeper elements and a waste receptacle that receives swept up waste particles. Front portion  304  comprises rotatable connections for two wheels  311  that permit device  300  to be pushed forward and back for sweeping action accomplishing the objects of the invention. Front portion  304  is also provided with a width-wise rectangular opening  310  adapted to provide allow effective contact between the rotating paddle or spatulate ends of sweeper elements  314  and a floor surface to be swept by device  300 . Front portion  304  extends rearward to upper rear portion  305  and lower rear portion  306 , which terminate in a downward sloping opening adapted to be releasably sealed during operation by rear door  307  hinged at an upper end via hinge  308  to upper rear portion  305 . Door  307  is provided with latch  309  so that it may connected with lower rear portion  306  during sweeping operation and opened for removal of waste particles.  FIG. 34  shows that wheel attachment extensions  313  are provided laterally from front portion  304  for attachment of wheels  311  (not shown). A waste receptacle part of device  300  comprises an internal cavity defined by inside surfaces of portions  305  and  306  and door  307 . 
       FIGS. 35 and 36  are, respectively, side and front views of enlarged bore sweeper element  314 , which are similar to the above described sweeper elements, except that a bore  316  defined by cylindrical support  315  is substantially increased in this embodiment. Arms  318  extend from connection  317  to a spatulate end  319  so that in rotation of sweeper element  314  causes a distal edge of end  319  to contact a swept floor surface to lift waste particles therefrom and into the waste receptacle part of device  300 . 
       FIG. 37  is an end view of a motor connector cylinder  320  adapted to engage a drive shaft of an electric motor. Cylinder  320  comprises an outer cylindrical wall  321  closed at one end by plate  322 , which defines screw holes for screw connection with another rotating cylindrical part. Plate  322  comprises a central connector section  323 , which is adapted to securely connect with a drive shaft of an electrical motor.  FIG. 38  shows cylinder  320  in cross section with a small, battery driven electric motor  327  with a drive shaft  328  aligned to be connected with central connector section  323 . The combination of motor  327  and cylinder  320  are critical to the operation of the present embodiment. 
       FIG. 39  is a front, cutaway view of a battery and controller housing  302  comprising top wall  330  which extends downward to front (not shown) and rear walls  365  and side walls  336 , which in turn are connected by floor wall  331 , all of which define an internal cavity  332 . Cavity  332  provides a small, compact space for location of battery  334  and controller  335 , which are secured to walls  365 . Controller  335  comprises switches extending to buttons or other user interface so that a user may switch device  300  on and off, i.e., battery  334  is connected by electrical connections through controller  335  to motor  327  to accomplish powering and on-off control of motor  327 . Downward arms  362  extend down from side walls  336  and floor wall  331  to support housing  302  above front portion  304  (as in  FIG. 33 ). Side walls  336  extend further downward to floor plates  339  and  342  on opposing downward arms  362 . From floor plate  339  extends cylinder  338  with an internal, bore  340  open at one end, which is aligned with and directed toward an identically dimensioned cylinder  341  with bore  343 , which cylinder  341  extends from floor plate  342 . By way of assembly description, floor plates  339  and  342  are adapted to be secured by a rotatable connection (such as a bolt or rivet  361  as in  FIG. 33 ) at a common axial location of cylinders  338  and  341  to left and right sides of front portion  304  (as in  FIGS. 33 and 34 ). In this way, the assembly of  FIG. 39  may be supported within an internal cavity of front portion  304 , whereby a user moving handle  301  forward and back causes the assembly of  FIG. 39  to rotate about axes of cylinders  338  and  341  with respect to front portion  304 . 
     Now again referring to the assembly of  FIG. 39 , motor  327  is lodged securely within bore  343  of cylinder  341  with drive shaft  328  extending beyond an opening of cylinder  341 . Motor connector cylinder  320  is located in closely fitting but slidable relationship about the outside surface of cylinder  341 , whereby drive shaft  328  of motor  327  is securely connected to cylinder  320  so that rotation of drive shaft  328  of motor  327  causes cylinder  320  to easily rotate as well. A sweeper element support cylinder  344  comprises a cylindrical wall  345  defining a bore  346 , open an end  347  but closed by plate  348  at end  349 . One end  347  of cylinder  344  is in a closely fitting but slidable relationship about the outside surface of cylinder  338 . End  349  comprises extensions from plate  348  to receive ends of screws  350 , which connect motor connector cylinder  320  to cylinder  344 , thereby providing effective transmission of rotational drive force of motor  327  to the combined lengths  351  and  353 , respectively, of cylinders  320  and  344 . Cylinders  338  and  341  have, respectively, lengths  352  and  354  to form a fixed rotational support for the connected cylinders  320  and  344 . Motor  327  is thereby effectively located within one end of said fixed rotational support, reducing overall number of parts and size of housing parts as compared with other embodiments of the invention. 
     Referring further to  FIG. 39 , sweeper elements  314  are closely fitting and fixed relationship with respect to each other (side by side and interlocking) and with respect to the outside surface of cylinders  314  and  320 . Representative sweeper elements  314  are shown in  FIG. 39 , however it is intended that sweeper elements  314  extend along the outside surface length of cylinders  320  and  344 . Operation of the present embodiment is initiated by a user pressing a button or switch at controller  335 , which in turn connects battery  334  with motor  327 . Motor  327 , fixed inside cylinder  341 , causes drive shaft  328  to rotate relative to cylinder  341 . Rotation of drive shaft  328  causes cylinders  320  and  344  to rotate in the same direction, which in turn causes sweeper elements  314  to rotation and sweep a floor surface. A clearance between cylinders  320  and  344  and floor plate  331  are provided for rotation and sweeper elements  314  and enclosure of the sweeper elements by front portion  304  ( FIGS. 33 and 40 ).  FIG. 40  shows a broken line position  307   a  of door  307  when it is in the open position.  FIG. 40  also shows an end view with floor plate  342  and side wall  336  cut away to expose ends of motor  327 , cylinder  341 , cylinder  320 , and cylindrical support  315  of sweeper element  314 , where the ends of sweeper elements  314  are shown as being arranged to rotate in close association with a top part of front portion  304  and extend out from opening  310  to contact a swept floor surface, such that ramp  360  assists swept particles to follow generally path  356  in waste receptacle  355 . Waste receptacle  355  is defined by portions  305  and  306  and door  307  to contain swirling and swept up waste particles during operation. 
       FIG. 41  is a bottom view of device  300  and  FIG. 42  is a top view thereof without the battery and controller housing and at a cross section downward arms  362  presenting through slots  363 . 
     In an alternate form of this embodiment, the assembly of  FIG. 39  may be fixed and non-rotatable with respect to front portion  304  ( FIG. 33 ) at connection  361 . Arms  362  may be severed and moved to another appropriate location connected with overall housing  303  so that a user can push the device  300  back and forth for sweeper operation. 
     The above design options will sometimes present the skilled designer with considerable and wide ranges from which to choose appropriate apparatus and method modifications for the above examples. However, the objects of the present invention will still be obtained by that skilled designer applying such design options in an appropriate manner.