Abstract:
A manually propelled, wheeled rotary brush having a handle and two wheels. The brush may have a generally cylindrical configuration which contacts the environmental surface on which the wheels ride, and may rotate about a horizontal axis disposed perpendicularly to the direction of travel as the wheels turn. The brush may be geared to the wheels, and may rotate faster than the wheels. The wheeled rotary brush may have a frame in which the gears are journaled. The handle may be propped in an elevated position by stabilizing legs disposed to engage the environmental surface at a point spaced apart from the brush. The brush may have replaceable brush elements which may be inserted into slots formed in a cylindrical core of the brush.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date under 35 USC 119(e) of the filing date of U.S. Provisional Application Ser. No. 61/107,561, filed Oct. 22, 2008, the contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention pertains to appliances for sweeping surfaces using brush bristle type sweeping elements, and more particularly to a wheeled appliance which sweeps a surface when rolled therealong. 
     BACKGROUND OF THE INVENTION 
     Sweeping environmental surfaces of light debris, such as clearing sidewalks of leaves and the like, is a domestic task that is encountered from time to time. Bristle bearing brooms have long been utilized for this purpose. However, a broom or brush must be wielded in a reciprocating motion when hand held. This is tiresome if the task is prolonged, and may take an objectionably long time to complete. 
     Motorized street sweeping vehicles having rotary brushes are known. These are clearly unsuitable for tasks of more limited scope than street sweeping. Even if miniaturized, the resulting powered sweeper would be cumbersome and heavy to the point that it would defeat the advantages of being powered. 
     There remains a need for a brush type sweeper which combines the ease of use of a manual implement with the rotary action of motorized street sweeping vehicles. 
     SUMMARY OF THE INVENTION 
     The present invention provides a rotary sweeper which is practical for sweeping tasks which are greater in scope than the nominal scope of sweeping the floor of a room in a typical residence, but which is generally manually operated. 
     The novel rotary sweeper comprises two wheels, a push handle, and a rotary brush which is rotated by the wheels as the wheels roll across an environmental surface. Such a rotary sweeper would be highly practical for sweeping sidewalks as the weight is borne by the wheels, thus sparing the user, while enabling the user to walk behind the rotary sweeper as sweeping progresses. The sweeper can thus sweep surfaces such as sidewalks at the rate of forward progress equal to that at which the user can walk. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Similar reference characters denote corresponding features consistently throughout the attached drawings. 
         FIG. 1  is a front perspective view of a manual rotary sweeper according to at least one aspect of the invention. 
         FIG. 2  is a mostly exploded view of  FIG. 1 . 
         FIG. 3  is a diagrammatic side view of an alternative drive mechanism for a manual rotary sweeper according to another aspect of the invention. 
         FIG. 4  is an enlarged detail view of a rotary brush for use in a manual rotary sweeper according to at least one aspect of the invention. 
         FIG. 5  is a fragmentary mostly exploded view of a drive mechanism for a manual rotary sweeper according to a further aspect of the invention. 
         FIG. 6  is an enlarged detail side view of a rotary brush for a manual rotary sweeper according to another aspect of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention comprises a manual rotary sweeper  10  which may be propelled by hand by a user (not shown). The manual rotary sweeper  10  may have a frame  12 , two main wheels  14 ,  16  rotatably mounted on the frame  12  in a location such that the two main wheels  14 ,  16  can contact and roll across a generally environmental surface such as the ground (not shown), and a handle  18  fixed to the frame  12  so as to enable the frame  12  to be pushed along the generally horizontal environmental surface in a direction of motion  20  while the user grasps the handle  18  and walks in the direction of motion  20 . This may be done in a manner similar to that by which a push type lawnmower (not shown) is operated. 
     The manual rotary sweeper  10  may comprise a generally cylindrical brush  22  which is fixed to the frame  12  either directly or indirectly, and which may contacts the environmental surface being rolled across by the two main wheels  14 ,  16 . The cylindrical brush  22  may be journaled in the frame  12  or otherwise supported so as to rotate about a horizontal axis  24  which is generally perpendicular to the direction of motion  20  as it contacts and rolls across the environmental surface being rolled across by the two main wheels  14 ,  16 . 
     The cylindrical brush  22  may be driven by a gear drive comprising rotatable elements which are disposed to rotate the cylindrical brush  22  about the horizontal axis  24  responsively to the two main wheels  14 ,  16  rolling across the environmental surface. 
     The cylindrical brush  22  may have a brushing surface  26  configured in generally cylindrical form. The brushing surface  26  may actually contact the environmental surface or alternatively may be dimensioned and configured so that it doesn&#39;t quite contact the environmental surface. For example, if desired to intercept and propel from its path articles of sufficient size, the brushing surface  26  may extend sufficiently even without actually contacting the environmental surface. 
     The brushing surface  26  and hence the cylindrical brush  22  may be generally cylindrical without being cylindrical in the strictest sense. For example, the cylindrical brush  22  may bear bristles  28 , the ends of which collectively form the brushing surface  26  and collectively suggest rather than literally establish a cylindrical form. 
     The manual rotary sweeper  10  may have a stabilizer disposed to support the handle  18  in an elevated position such as the position depicted in  FIG. 1  when the two main wheels  14 ,  16  are resting on the environmental surface. The stabilizer may take the form of at least one leg  30  fixed to the frame  12 . The leg  30  may terminate in a foot disposed to engage the ground when the two main wheels  14 ,  16  are resting on the environmental surface. The foot may take the form of a rolling element which can roll along an environmental surface, such as a stabilizer wheel  32 . The stabilizer wheel  32  may be mounted on the leg  30  so as to be able to swivel about a non-horizontal axis, so that the stabilizer wheel  32  can turn direction independently of the main wheels  14 ,  16 . In particular, the stabilizer wheel  32  may be able to turn direction when the two main wheels  14 ,  16  roll in a constant direction such as the direction  20 . The stabilizer may comprise a second leg  34  which may be essentially similar in structure and function to the leg  30 . 
       FIG. 2  shows axial alignment of the cylindrical brush  22  with the main wheels  14 ,  16 . The main wheels  14 ,  16  may be mounted to the frame  12  by riding on an axle (not shown) in well known fashion and being secured there by nut  36  and washer  38  for example. 
       FIG. 3  shows a partial drive arrangement which may be utilized to drive the cylindrical brush  22  and a height adjustment feature for elevating the cylindrical brush  22  relative to the environmental surface. The cylindrical brush  22  may comprise a side plate  40 . The partial drive arrangement of  FIG. 3  includes a central first gear  42  fixed or drivably engaging the cylindrical brush  22  and three surrounding intermediate gears  44 ,  46 ,  48  which drivably engage the central first gear  42 . The intermediate gears  44 ,  46 ,  48  may in turn a second gear (not shown) formed as part of or solidly fixed to a main wheel  14  or  16 . The position of two of the intermediate gears  44 ,  46 ,  48  may be adjusted relative to the plate  40  so that the plate  40  and the cylindrical brush  22  are moved vertically either up or down relative to the ground or environmental surface. 
     This may be accomplished by forming an arcuate slot  50  in the plate  40 . A second arcuate slot (not shown) of suitable geometry may complement the arcuate slot  50  so that the axis of the cylindrical brush  22  can shift to achieve the vertical adjustment. 
     Rotational engagement among the central first gear  42  and the intermediate gears  44 ,  46 ,  48 , and a gear (not shown) fixed to a main wheel  14  or  16  causes any one of these gears  42 ,  44 ,  46 ,  48  to be drivably engaged with the others. The central first gear  42  may comprise a splined shaft (not shown) which engages a correspondingly splined hole  52  formed in the core  54  of the cylindrical brush  22 . The splined hole  52  may be regarded as a gear of the cylindrical brush  22  to which torque is transmitted from the intermediate gears  44 ,  46 ,  48  via the central gear  42 , which may be regarded as a brush drive gear. 
       FIG. 5  depicts a drive arrangement for a manual rotary sweeper  110  according to a further aspect of the invention. The manual rotary sweeper  110  may comprise a frame  112  which also forms a handle  118 . The frame  112  may comprise a support plate  160  bearing an arcuate slot  162 . A hole  164  may be formed in the support plate  160  for receiving and providing journaled support to an axle  166  to which are mounted a main wheel  114  and a driving gear  168 . A secondary support plate  170  may bear a hole  172  for receiving and providing journaled support to a brush shaft  174  to which is fixed a cylindrical brush  122  of course, and a driven gear  176 . The secondary support plate  170  may be adjustably positioned on the support plate  160  by passing screws  178 ,  180  through an arcuate slot  182  formed in the support plate  160 , and into screw holes  184 ,  186  formed in the secondary support plate  170 . Before tightening the screws  178 , 180 , the secondary support plate  170  may be moved along the arcuate slot  182  to adjust height of the cylindrical brush  122  on its frame  112 . 
     In the arrangement of  FIG. 5 , the gear  176  may be considered to be a first gear fixed to the cylindrical brush  122 , and the gear  168  may be considered a second gear which is drivably engaged with the first gear (gear  176 ). 
     It should be mentioned here that the manual rotary sweeper  110  may be bilaterally symmetrical so that the structure shown on the right side of the manual rotary sweeper  110 , as viewed from the vantage point of a person holding the handle  118  and pushing the manual rotary sweeper  110 , may be repeated in mirror image on the left side (not shown). Therefore, while only one second gear (gear  168 ) is actually depicted, the two main wheels (i.e., the main wheel  114  and its counterpart on the left side of the manual rotary sweeper  110 , not shown) may collectively comprise at least one second gear and optionally two second gears. The first gear (gear  176 ) may engage one of the second gears and if a second first gear (not shown) is provide on the left side of the manual rotary sweeper  110 , then two first gears may engage two second gears in mutually rotatable fashion. 
     If the arrangement of  FIG. 3  is adopted, then there would be at least one intermediate gear (i.e., one of the intermediate gears  44 ,  46 ,  48 ) interposed drivably between the first gear and the at least one second gear. 
     Returning to  FIG. 5 , the gear drive established by the gear, wheel, and axle components described with respect to the manual rotary sweeper  110  may be said to comprise a gear drive therefor. The gear drive may be disposed to rotate the cylindrical brush  122  at a first rotational speed when the two main wheels (i.e., the main wheel  114  and its counterpart at the opposed left side) rotate at a second rotational speed. For example, and as depicted, the first rotational speed of the cylindrical brush  122  will be greater than the second rotational speed of the two main wheels. 
     The holes  164  and  172  and their respective supporting elements, such as the frame  112 , the support plate  160 , and the secondary support plate  170  may be said to comprise a journaling arrangement which constrains the rotatable elements of the drive against motion relative to the cylindrical brush  122  which motion is other than rotation about their drive axes. If this constraint were not present, one of the gears of the gear drive could walk or rotate ineffectually about another member of the gear drive. A similar or another constraint arrangement may be incorporated into the arrangement of  FIG. 3  if desired to assure operability. 
       FIG. 6  shows a feature which enables ready replacement of part of a brush element, such as the bristles  28  of the cylindrical brush  22  of  FIG. 1 . In the arrangement of  FIG. 6 , a cylindrical brush, which in other ways may be a structural or functional equivalent of the cylindrical brushes  22  and  122 , has a core  254  for holding and supporting a brushing surface, which may comprise the collective outer ends of bristles similar to the bristles  28 . The core  254  may bear recesses in the form of T-slots  256 . The brushing surface may be provided in replaceable complementing sections such as the section  258  which may be received within the T-slots  256 . Close cooperation between the solid base  260  of each section such as the section  258  is such that the section  258  is solidly held and retained within its T-slot  256 , while enabling the complementing sections  258  to be removed from and installed on the core  254  by sliding laterally in a direction parallel to the horizontal axis (not shown, but similar to the horizontal axis  24  of the manual rotary sweeper  10 . 
     It should be understood that any feature presented herein may be incorporated into or omitted from a manual rotary sweeper according to the present invention where feasible, such as the manual rotary sweepers  10  and  110 . For example, the manual rotary sweeper  110  may have stabilizers such as the stabilizer legs  30 ,  34 . 
     The present invention is susceptible to variations and modifications which may introduced thereinto while conforming to the inventive concept. For example, a cylindrical brush such as the cylindrical brush  22  may be arranged at an acute angle to the direction of motion rather than being perpendicular thereto. The actual angle may be adjustable. The cylindrical brush may be formed in two sections (not shown) which collectively form a V configuration for example. 
     While the present has been described in connection with what is considered the most practical and preferred embodiments, it is to be understood that the present invention is not to be limited to the disclosed arrangements, but is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all modifications and equivalent arrangements which are possible.