Patent Publication Number: US-8117705-B2

Title: Rotary broom with gearbox drive

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This non provisional patent application claims priority to the provisional patent application having Ser. No. 61/338,722, having filing date Feb. 23, 2010. 
    
    
     BACKGROUND OF THE INVENTION 
     The rotary broom with gearbox drive relates to mechanical equipment and more specifically to a rotary broom that operates at selected angles without the usage of a constant velocity joint and related drive line. 
     Parking lots, paving projects, construction sites, airports, farms, ranches, agricultural operations, and other projects often have large generally flat or gently curved surfaces. The surfaces often collect dust and other debris from the atmosphere, workers, equipment, and vehicles. From time to time, the surfaces require cleaning for safe usage or for preparation before application of another layer or lift of material. Workers, equipment, and vehicles that use a surface generally call for a minimum of debris impacting them. Particularly at airports, cleansing taxiways, aprons, and runways of debris is paramount to avoiding foreign object damage to aircraft engines and grounding of aircraft. After a harvest, a feeding operation, or an interval of usage, barns, stalls, sheds, and platforms along with other agricultural facilities require cleaning. Clean agricultural facilities lead to healthier and heavier livestock, greater dairy production, and higher quality harvested grain and vegetables. 
     When the surfaces are dry, the debris can be swept from the surface manually by a crew or more often by mechanical equipment. A crew utilizes many brooms pushed in formation through a facility, cleaning the floor of debris. However, this method has high labor costs and the crew likely tires before larger facilities are cleaned. 
     DESCRIPTION OF THE PRIOR ART 
     Over the years, equipment manufacturers have developed various surface cleaning implements. Implements wash surfaces, generally hard surfaces such as concrete and bituminous concrete. Implements also sweep surfaces removing debris by pushing from a blade, suction from a vacuum, brushing from a broom, and the like. Manufacturers have developed various rotary brooms with bristles along a central rotating shaft turned by the power take off from a tractor or electrical supply from a vehicle. Sweepster from Delhi, Iowa makes various brooms. The brooms attain an angle from the path of the vehicle ranging from to 30° right, 15° right, centered, 15° left through 30° left. The brooms pivotally connect to a vehicle so that the brooms follow the ground surface yet move upwardly upon encountering an obstacle or upon operator command. The brooms have a spring loaded chain extending to the vehicle that accommodates vertical changes in the broom, or floating. Brooms also must operate as the vehicle goes forward or reverse. 
     More particularly, Sweepster produces a broom upon a separate three point mounting frame that pivots both right and left. The broom has a head upon a main tube which accommodates floating of the broom during usage. The broom turns upon a drive line. The drive line extends from a vehicle, often a tractor, to a ninety degree gearbox upon the mounting frame. Then the drive line continues from the gear box to one side and on to a constant velocity joint, or CV joint. The CV joint handles the various angles of the drive line and floating however, CV joints wear prematurely in the absence of lubrication and replacement of a CV joint incurs significant labor costs. The drive line also has a ninety degree T shaft gearbox. This gearbox allows an operator to disconnect the various shafts of a driveline so that the broom can rotate either in forward or reverse. An operator disconnects all of the shafts from the T shaft gearbox, removes the gearbox from the mounting frame, inverts the gearbox 180°, secures the gearbox to the mounting frame, and reconnects all of the drive shafts so the broom rotates in the opposite direction. 
     Another manufacturer York Modern Corp. of Unadilla, N.Y. provides a broom that pivots during vertical floating. This broom pivots where its three point hitch pins connect to the lower lift arm of the typical tractor hitch. This broom has a gear box bolted to the main brush head frame. When an operator angles the broom during usage, the gear box attains the same angle. The York brooms include a driveline from the tractor, or other mover, power take off to the gearbox, a ninety degree gearbox in particular. Because the gearbox attains the same angle as the frame and the broom, the universal joints of the driveline also attain the angle of the gearbox. Angling the broom acutely also angles the driveline and its joints at that sharp angle as well. Joints operated at acute angles tend to wear prematurely. 
     For brooms upon three point hitches powered by a PTO, operators require that the brooms operate in both forward and reverse. In some usages, operators drive a tractor forward and the broom rotates forward. At other usages, operators drive a tractor in reverse and expect the broom to also rotate in reverse. Then in particular situations, operators drive a tractor in one direction and rotate the broom in the opposite direction. 
     The drive line also has a ninety degree T shaft gearbox. This gearbox allows an operator to disconnect the various shafts of a driveline so that the broom can rotate either in forward or reverse. An operator disconnects all of the shafts from the T shaft gearbox, removes the gearbox from the mounting frame, inverts the gearbox 180°, secures the gearbox to the mounting frame, and reconnects all of the drive shafts so the broom rotates in the opposite direction. 
     The present invention overcomes the disadvantages of the prior art and provides a rotary broom with a gearbox drive. This rotary broom operates in either a right or left angle without a CV driveline. The drivelines of the invention operate using drivelines at less than a 30° angle. The rotary broom allows for ready adjustment to a broom angle when the tractor moves forward or rearward. Operators of the rotary broom of this invention can make the adjustment using hand tools readily available to drivers, mechanics, farmers, ranchers, and growers. 
     SUMMARY OF THE INVENTION 
     Generally, the present invention is a rotary broom mounted upon a slotted plate that pivots upon a double gearbox. The broom includes bristles upon an axle within a shield. The axle receives power from a chain drive or other means upon one end. The chain drive receives its power from a driveline extending from a top gear box. The top gearbox orients in the direction of the chain driveline and delivers its power through an output shaft into the chain driveline. The top gearbox joins to the slotted plate that turns in the same direction as the angle of the broom. The top gear box receives its power through an input shaft generally perpendicular to the output shaft that drives the chain. The top gearbox input shaft extends downwardly and becomes the output shaft of the bottom gearbox. The output shaft of the bottom gearbox and the input shaft of the top gearbox is generally vertical, that is, perpendicular to the rotational axis of the broom. The bottom gearbox has an input shaft that connects to a PTO of a tractor or other vehicle. The present invention receives rotational power from a PTO, rotates it 90° upwardly, then rotates it 90° downwardly and at an angle laterally to reach the driven end of the broom. 
     There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and that the present contribution to the art may be better appreciated. The present invention also includes a slotted guide plate, a pivotable gearbox, an invertable gearbox, and related framing supporting the guidebox and three point hitch connection. Additional features of the invention will be described hereinafter and which will form the subject matter of the claims attached. 
     Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of the presently preferred, but nonetheless illustrative, embodiment of the present invention when taken in conjunction with the accompanying drawings. Before explaining the current embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
     One object of the rotary broom with gearbox drive is to provide a broom that can be readily adjusted into a left or a right angle and attached to an existing three point hitch. 
     Another object of the rotary broom with gearbox drive is to provide such a gearbox drive that allows for ready detachment of a driveline. 
     Another object of the rotary broom with gearbox drive is to provide such a gearbox that allows for inversion of one gear box in relation to the other gearbox. 
     Another object of the rotary broom with gearbox drive is to provide such a gearbox drive that operates when the powered vehicle moves in forward or reverse. 
     Another object of the rotary broom with gearbox drive is to provide such a broom that can be installed with hand tools upon equipment readily available upon a farm, a ranch, or a jobsite. 
     Another object of the rotary broom with gearbox drive is to provide such a broom that has a low cost of manufacturing so the farmers, ranchers, contractors, operators, co-ops, haulers, elevators, yards, and depots can readily purchase the broom through existing sales outlets. 
     These together with other objects of the invention, along with the various features of novelty that characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In referring to the drawings, 
         FIG. 1  shows an isometric view of the rotary broom with a gearbox drive of the present invention; and, 
         FIG. 2  describes an exploded view of the framing and power train of the present invention. 
     
    
    
     The same reference numerals refer to the same parts throughout the various figures. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention overcomes the prior art limitations by providing a rotary broom with a gear box drive that readily changes from a right orientation to a left orientation and that supports a pivoting drive line that delivers power to the broom. The rotary broom  1  of this invention begins in  FIG. 1  with a broom B formed of a plurality of bristles mounted upon a centered axis. The broom has an apparent cylindrical shape formed by the bristles. As the bristles wear during usage, the shape of the broom alters. From time to time, operators of the invention replace the bristles and at a longer time interval, operators rebuilding the broom from the axle outwardly. The broom has a cover D extending for the length of the broom and partially around the circumference, approximately one quarter to one third. The cover is generally located upwardly and rearwardly from where the broom engages a surface subject to cleaning. The broom receives power from a chain drive C generally upon one end of the broom, here shown in the foreground. The chain drive C receives its power from a constant velocity driveline  2 , or CV driveline. The CV driveline has a generally elongated shaft with two ends. Each end has a universal joint with a short stub that provides for connecting the driveline to a power source or a power recipient. The universal joints allow for connection of the CV driveline to a power source and a power recipient spaced apart and angularly separated. The shaft of the driveline transmits power between the universal joints at each end. The CO driveline  2  connects to the assembly  3  of the present invention that supports the broom B and receives power from the source, such as a tractor, piece of equipment, or truck. 
     The assembly  3  begins with a frame  4  generally rectangular in shape and open. The frame supports a three point hitch connection between the invention and a vehicle, such as a tractor not shown. The frame is generally open to allow passage of a PTO driveline  5  from the tractor into the assembly. The frame has a tongue  6  extending generally perpendicular from the frame and opposite the PTO driveline  5 . Spaced away and above the tongue, the assembly includes a base plate  7  that has a pattern of holes through it as later shown. Generally centered upon the base plate, the present invention includes a double gear box  8  having a top gear box, not shown, and a bottom gear box  8   b , shown. The bottom gear box connects with the PTO driveline to receive power into the invention from the tractor. A shield  9  covers the connection of the bottom gear box to the PTO driveline. Forward of the bottom gear box and above the shield, a guide plate  10  attaches to the top gearbox as later shown. The guide plate includes an arcuate slot  10   c  therein. The slot has approximately 90° of curvature towards the direction of the chain drive of the invention. Above the guide plate, a two piece casing  11  covers the top gearbox. 
     Generally centered upon the broom and beneath the cover D, the present invention has a semi-circular pivot plate  12 . The pivot plate  12  joins to the framing of the brush B and extends outwardly from the brush towards the frame  3 . The pivot plate has a curved shape where the curved portion passes beneath the base plate  7  and above the tongue  6 . The pivot plate rotates about a generally centered bolt connecting to the base plate and the tongue. Proximate to the center of the pivot plate&#39;s joint to the framing of the brush, the invention h as a stem  13  extending upwardly from the pivot plate, past the base plate, and nearly abutting the guide plate  10 . The stem generally ends below the guide plate. The stem has a threaded aperture in its top that admits a bolt. During usage a bolt passes through the arcuate slot  10   c  of the guide plate  10  and secures to the top of the stem. Tightening of the bolt fixes the orientation of the brush framing at an angle desired by the operator of the vehicle. Upon loosening the bolt, the stem rotates beneath the arcuate slot  10   c  as the pivot plate turns upon the tongue when an operator pushes the brush framing. The pivot plate also includes a bumper  14  locating outwardly from the stem towards the chain drive C. The bumper extends into the pivot plate a short distance and prevents further turning of the pivot plate when it abuts the edge of the base plate. The bumper prevents an operator from turning the brush framing too far and snapping the CV driveline  2  or damaging the gear box  8 . 
     Having described the invention generally as assembled in  FIG. 1 ,  FIG. 2  shows the components of the present invention in more detail. The assembly  3  has its generally rectangular frame  4 . The frame has two generally parallel and mutually spaced apart sides  15 . The sides are generally rectangular in shape having a length, a longitudinal axis, two sides, and two ends perpendicular to the sides. One end is generally square and denotes the bottom being proximate to the surface being swept and the opposite end is curved with a slight concave edge in one side generally proximate the brush cover D. The longitudinal axis of the sides is generally upright, that is perpendicular to the surface being swept. The sides are joined by an upper member  16  that has a hitch clip  17  centered thereon. The hitch clip has a somewhat T like shape with a split web. The clip has a plurality of holes that allow for connection to various existing three point hitch systems. The upper member is generally elongated and of narrower width than a side  15 . The upper member connects to the sides proximate the corner above the concavity as shown. Preferably, the upper member is tubular steel welded to steel sides. Opposite the upper member, the frame has a lower member  18  that spans between the sides generally parallel to the upper member. The lower member has a thickness less than the width of the side, here shown as approximately one half of the width of a side. The lower member connects to the sides proximate the bottom end and towards the brush framing. Preferably, the lower member is also tubular steel welded to steel sides. The upper member and the lower member have generally rectangular cross sections presenting a flat face towards the brush framing. 
     Outwardly from the lower member and generally opposite the hitch, the frame has the tongue  6 . The tongue has a generally tapered shape with a wide base,  6   a , locating upon the center of the lower member. Outwardly from the lower member, the tongue narrows in width to a tip,  6   b , generally proximate the brush framing. The tongue has a thickness providing bending resistance as the tongue connects to the lower member in a cantilever manner. Above the tongue, the frame has the base plate  7 . The base plate is generally in a plane parallel to the tongue and perpendicular to the lower member. The base plate has a generally rectangular shape with two short ends and two long sides perpendicular to the ends. The sides are approximately the same length as the tongue. As shown, one side, outwardly from the centerline of the tongue, is generally shorter than the other side. The ends and sides are proportional so that the base plate is generally not elongated. The base plate connects to the lower member slightly above the tongue, as at  6   c , so that the pivot plate  12  may rotate between the base plate and the tongue during usage. The base plate includes a pivot hole  7   a  beneath which the pivot plate connects along its curved edge using a bolt and plurality of washers. The pivot hole locates away from the center of the tongue towards the lower member. Proximate the end of the tongue away from the frame, the base plate has a lock hole  7   b  that receives a pin, not shown, for securing the pivot plate, and hence brush, generally parallel to the frame. The base plate has its sides extending perpendicular to the lower member with the longer side, as at  6   d , shown slightly off the centerline of the tongue towards the chain drive C leaving a portion of the tongue visible in this view. The remainder of the base plate extends away from the chain drive C. Perpendicular to the shorter edge, as at  6   e , the baseplate  10  has a flange  19 . The flange is welded to the base plate and is located away from the lower member at the corner of the base plate. The flange  19  has a plurality of holes allowing for connection of the gearbox as later described. 
     Behind the frame, that is, opposite the brush framing, the assembly includes a PTO driveline  5  that connects to a tractor or other equipment. The PTO driveline has a first end  5   a  and an opposite second end  5   b . The first end connects with the PTO shaft from a tractor. The second end connects to the gear box as later described. The second end passes between the sides  15  of the frame  3  and extends over the baseplate  10  as previously shown in  FIG. 1 . The second end  5   b  of the PTO driveline receives protection from debris because of the shield  9 . The shield is generally an inverted U shaped, cold formed steel member having two parallel flanges, or branches. Upon one flange, the shield has at least two holes for a bolted connection to the flange  19  generally near the lower member  18 . The shield also provides protection to any operators proximate the gearbox  8  of the invention from the rotating second end  5   b  of the PTO driveline. 
     Generally opposite the shield  9  and the tongue  6 , a gusset  20  spans from an end of the lower member  18  to the adjacent side  15  towards the chain drive C. The gusset is a cold formed steel member welded to the lower member and the side, providing further stiffness to the frame. 
     Turning inwardly from the frame, the present invention includes a double gear box  8  that has a top gearbox  8   a  and a bottom gearbox  8   b  beneath the top gearbox. The bottom gear box has an input shaft  8   c  extending outwardly from the gear box generally perpendicular to the lower member  18 . As shown, the bottom gear box has a generally cube like shape with six face. Upon the face parallel to the input shaft and opposite the chain drive C, the bottom gear box has a plurality of holes that align with the holes in the flange  19  for a bolted connection. Meanwhile, the input shaft  8   c  connects to the second end  5   b  of the PTO driveline. The input shaft transmits power into the gearbox. The bottom gear box then rotates the power provided by the input shaft ninety degrees to an internal shaft, not shown, generally parallel to the plane of the sides  15  and perpendicular to the lower member  18 . The internal shaft transmits the mechanical power into the top gear box  8   a . The top gear box again rotates the power ninety degrees and divides it between two output shafts  8   d . The two spaced apart output shafts  8   d  are generally coaxial along an axis parallel to the lower member  18  of the frame, that is, perpendicular to the input shaft  8   c  and the PTO drive line  5 . As shown, one output shaft  8   d , generally proximate the chain drive C, connects to a second end  2   b  of the brush driveline  2 . This output shaft allows for rotating the brush towards the chain drive, or away from the flange  19 . Opposite the second end  2   b , the brush driveline  2  has a first end  2   a  that connects to the chain drive that drives the brush B. 
     As described earlier, the top gear box  8   a  can be removed from the internal shaft and rotated one hundred eighty degrees. This allows usage of the other output shaft  8   d , away from the chain drive C, so that brush rotates away from the chain drive, or towards the flange  19 . Similar to the bottom gearbox, the top gearbox has a cube like shape with six faces. Upon the face outwardly from the output shafts and opposite the upper member  16 , the top gear box has at least two holes that allow for mounting of the guide plate  10 . 
     The guide plate is generally a cold formed steel member having an angled cross section with two perpendicular legs  10   a ,  10   b . An upper leg, as at  10   a , is generally solid but for at least two holes that allow for a bolted connection of the guide plate to the top gearbox  8   a . The lower leg, as at  10   b , is perpendicular to the upper leg and generally opposite the holes of the upper leg. The lower leg is generally longer than the upper leg. The upper leg has a somewhat trapezoidal shape formed from removing one corner of a rectangular shape, the corner being away from the upper leg and toward the chain drive C as shown. The upper leg has an arcuate guide slot  10   c  fitting within the somewhat trapezoidal shape. The arcuate guide slot  10   c  has a curve extending through approximately ninety degrees of arc and a radius of curvature extending from a point where the upper and lower legs join generally opposite the chain drive C. As shown in the drawing, the arcuate guide slot is generally convex. 
     The top gearbox  8   a , output shaft  8   d , second end  2   b  of the driveline, and the upper leg  10   a  generally locate within the casing  11  as previously shown. The casing has a front casing as at  11   a  and an opposite rear casing  11   b . The rear casing has a generally C shaped cross section with one open end proximate the chain drive C and an opposite closed end. The lower flange of the rear casing is notched upon the center to allow passage of the PTO driveline  5  beneath it. The front casing has a generally C shaped cross section also with one open end proximate the chain drive C and an opposite closed end. The web of the front casing has two holes proximate the upper flange for bolting to the top gear box above the upper leg  10   b  of the guide plate. Beneath the two holes, the web of the front casing has a large aperture that allows access to the top gearbox. 
     Outwardly from the gearbox  8  and the tongue  6 , the present invention has the semi-circular pivot plate  12 . The pivot plate has a generally semi-circular shape when viewed in plan, that is, when installed in the invention and looking downwardly behind the brush. The pivot plate has its semi-circular edge  12   a  locating inwardly, that is, towards the gear box. Opposite the semi-circular edge, the pivot plate has a straight edge,  12 , generally upturned at a ninety degree angle. The straight edge defines the width of the pivot plate, generally the diameter of the semi-circular edge. The straight edge has reinforcement from two is gussets  12   c  welded from the straight edge to the semi-circular portion of the pivot plate. The gussets are generally perpendicular to both the semi-circular portion and the straight edge. Inwardly from the gussets, the straight edge has various apertures for mounting the straight edge to the framing of the brush B. inward from one gusset, here shown proximate to the gearbox, the straight edge has a bumper  14 . The bumper extends in the same direction as the gusset, that is, towards the semi-circular edge  12   a . The bumper joins to the straight edge, generally by welding, and presents a round wheel  14   a . The wheel has a lesser diameter than the length of the bumper. The wheel adjoins the long edge  6   d  of the base plate  7  when the brush B is turned to the maximum angle permitted towards the chain drive. Along the straight edge and generally opposite the bumper, the pivot plate  12  includes a stem  13 . 
     The stem generally joins to the upturned straight edge, preferably by welding, and extends well above the straight edge. The stem is generally perpendicular to the straight edge and the plane of the semi-circular portion of the pivot plate. Opposite the straight edge, the stem has a cap  13   a  welded on to it. The cap extends inwardly from the stem towards the semi-circular edge  12   a . The cap is generally perpendicular to the remainder of the step and generally parallel to the plane of the semi-circular portion of the pivot plate. The cap has a threaded aperture inwardly from the stem that aligns with the guide slot  10   c  of the guide plate  10 . During usage, an operator adjusts the angle of the brush B by rotating the brush framing towards the chain drive while the cap  13   a  passes beneath the guide plate along the path of the guide slot. A bolt  13   b  placed through the guide slot  10   c  into the threaded aperture of the cap secures the brush B at the desired angle. To reach the desired angle, the semi-circular portion of the pivot plate  12  has a pivot hole  12   d  generally centered upon the plate, away from the straight edge, and proximate the curved edge  12   b . The pivot hole  12   d  is approximately midway along the spacing between the stem  13  and the bumper  14 . The pivot hole  12   d  aligns with the pivot hole  7   a  in the base plate  7 . The pivot plate turns upon a pin or bolt placed through the pivot hole in the base plate and the pivot hole in the pivot plate. This arrangement allows the pivot plate to rotate about an axis through the pivot hole  7   a  as it passes between the base plate  7  and the tongue  6 . Inwardly from the pivot hole  12   d , the pivot plate has a lock hole  12   e  that receive another pin or bolt placed through the outer hole  7   b  for locking the brush B generally perpendicular to the PTO driveline as during usage when the brush is perpendicular to the direction of motion of a vehicle. 
     From the aforementioned description, a rotary broom with gearbox drive has been described. The device is uniquely capable of repositioning a top gear box upon a bottom gear box so that a brush can rotate upon a tongue of a frame to achieve an angled orientation relative to the direction of movement of a vehicle supporting the brush. The device allows for temporarily fixing the angle of the brush using a slotted guide plate attached to the top gearbox. The device and its various components may be manufactured from many materials, including but not limited to, steel, ferrous and non-ferrous metals, their alloys, select polymers, and composites. 
     As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. Heretofore, those skilled in the art have not recognized a double gear box and slotted guide plate allow for repositioning of a drive line in a rotary broom. Therefore, the claims include such equivalent constructions insofar as they do not depart from the spirit and the scope of the present invention.