Abstract:
A screeding attachment for an industrial utility vehicle. The screed and vehicle in combination provide a low cost, maneuverable and versatile screeding unit for screeding small and medium size pavements such as driveways, sidewalks, slabs and surfaces inside buildings and the like. A see-through frame supported on castered wheels and a see-through distribution and deposition system for metering and depositing paving materials in the path of a grooved cylindrical screed provide an apparatus for continuously laying a screeded slab under the direct observation of an operator in the industrial utility vehicle.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 60/071,534, filed Jan. 15, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a screeding attachment that is securable to the bucket tilt mechanisms of an industrial utility vehicle to provide a low cost highly maneuverable and versatile self propelled screeding apparatus. More specifically this invention relates to an attachment which detachably secures a special function apparatus to an industrial utility vehicle to provide a low cost self propelled special function piece of equipment while not requiring the dedication of the industrial utility vehicle to that special function. The special function of the attachment of this invention is the screeding of flowable paving materials. 
     The use of a simple beam as a screed to level paving materials has been practiced since the dawn of paving technology. 
     Self propelled screeds are known in the art. Brandstetter, U.S. Pat. No. 3,526,173, is one such self propelled screeding apparatus. 
     The employment of special function attachments which are secured to the bucket tilt mechanisms of industrial utility vehicles is also known in the art. The instant inventor&#39;s U.S. Pat. No. 5,529,131 is for one such an attachment. 
     There has been a long felt and unfulfilled need in the art for a low cost, maneuverable, self propelled screeding apparatus for pouring small and moderate size pavement jobs such as driveways, sidewalks and slabs inside structures. 
     There has been a long felt and unfulfilled need in the art for a self propelled screeding apparatus as described above that is adaptable to a wide range of screeding mechanisms, controls, guides and aids. 
     There has been a long felt and unfulfilled need in the art for a means for distributing and depositing paving materials in the amount desired and at the location desired so as to minimize the amount of paving material to be moved in order to strike off and true the surface being poured. 
     This invention relates to solutions to the problems raised above and to improvements to existing solutions to those problems. 
     SUMMARY OF THE INVENTION 
     The invention in its simplest form is a screeding attachment for an industrial utility vehicle. The attachment includes a substantially rectangular frame having a longitudinal axis along the direction in which screeding will be performed, a vehicle end member, and a screed end member positioned transverse to the longitudinal axis. The frame further includes a first frame side member and a second frame side member positioned parallel to the longitudinal axis, one to each side of the frame. The vehicle end frame member has as a part thereof a coupling means which is engageable with and disengageable from a bucket tilt mechanism of an industrial utility vehicle. The vehicle end frame member is positioned so as to permit the operator of a utility vehicle to which the screeding attachment is attached to observe the functioning of a screed attached to the screed side member. The first side member and the second side member each have depending therefrom a ground engaging castered wheel assembly. 
     In general terms, the invention involves the provision of a novel means for distributing and depositing paving materials uniformly and continuously in front of the screed while preserving an operator&#39;s view of the screed, and a novel screed that exploits the uniform deposition of paving material and the operator&#39;s view of the screed to achieve a superior screeding of the paving materials. 
     Other objects and utilities provided by this invention will be made apparent from the following specification, drawings, and claims. 
    
    
     DESCRIPTION OF THE DRAWING 
     FIG. 1 is an isometric view of a screeding apparatus constructed according to a preferred embodiment of this invention. 
     FIG. 2 is a side elevational view of the screeding apparatus shown in FIG. 1, shown attached to an industrial utility vehicle. 
     FIG. 3 is a top plan view of the screeding apparatus and utility vehicle shown in FIG.  2 . 
     FIG. 4 is an isometric view of the screed shown in FIGS. 1 through 3, showing paving materials being distributed and deposited in the vicinity of the screed. 
     FIG. 5 is an isometric view of a grooved cylindrical screed employed in a preferred embodiment of the present invention. 
     FIG. 6 is a side elevational view of the screed shown in FIG.  5 . 
     FIG. 7 is a side elevational view of the screed attachment of the present invention, having a distribution and deposition means and a cylindrical screed. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the drawing figures, like numbers refer to like members. The proportions of some elements have been modified to facilitate illustration. 
     Referring now to FIGS. 1 through 3, the screeding apparatus  1  of this invention is shown in simplified form. According to the present invention, the screeding apparatus  1  includes a substantially rectangular frame  2  having a longitudinal axis  3  lying in the direction in which screeding will occur. A vehicle end member  4  and a screed end member  5  are positioned transverse to axis  3 . A first side frame member  6  and a second side frame member  7  are positioned parallel to axis  3 . The frame  2  is connected to a utility vehicle  9  by means of a coupling member or means  8 , which is incorporated with vehicle end member  4 . The frame  2  constructed and positioned so as to permit the operator of utility vehicle  9  to observe the operation of a screed  10 , attached to the screed end member  5 . A first side member  6  and second side member  7 , connected together by vehicle end member  4  and screed end member  5 , have depending therefrom ground engaging castered wheel assemblies  11 . 
     In the most preferred embodiment, the utility vehicle  9  is a skid steer loader, with front wheels  13  and rear wheels  14 . The screeding apparatus  1  of the present invention is mounted to conventional bucket arms  16  by a bucket tilt mechanism  12 , in the place where the bucket (not shown) of the skid steer loader is normally mounted. The arms  16  conventionally have the ability to be raised and lowered, and in fact they can be lowered enough that the front wheels  13  are lifted off the ground or other support surface on which the vehicle  9  is resting. When the screeding apparatus  1  is connected to vehicle  9 , and the arms  16  are lowered to that extent, so as to raise front wheels  13  of the vehicle off of the ground, the combination of screeding apparatus  1  and vehicle  9  can pivot about rear wheels  14  on castered wheels  11  as illustrated schematically in FIGS. 2 and 3. This provides a highly maneuverable self propelled screeding apparatus. 
     When the front wheels  13  of vehicle  9  are raised off of the ground, the screeding apparatus  1  is supported, as indicated above, by the widely spaced castered wheels  11  and the closely spaced rear wheels  14  of vehicle  9 , a three point support for the moving screeding apparatus is formed, establishing a plane to which screed  10  may be adjusted by means of adjustments  15  to provide a screeded pavement of a uniform thickness on top of the plane over which the screeding apparatus moves. 
     Adjustments  15  are shown schematically as hand wheels and screeding apparatus  1  is guided by its underlying plane. The art of screeding abounds in a very great number and many kinds of controls, guides, and adjustments to which the screed apparatus of this invention can be adapted. The underlying invention is sufficiently accommodating to adapt to most of the forms of guiding adjusting and control that are known in the art, including laser, hydraulic and pneumatic controls, without departing from the scope of the invention. 
     Another embodiment of the invention is shown in FIG.  4 . As there shown, screeding apparatus  17  is shown to be screeding paving material  24  distributed and deposited by paving material distribution and deposition means  20  into the path of screed  10 . Distribution and deposition means  20  is designed to be supported on frame  2  of FIGS. 1-3 and includes a hopper  21  and a paving materials supplier  22 . Hopper  21  is provided with a bottom opening  23  through which paving material  24  is discharged. A belt conveyor  25  passes under bottom opening  23 , and an adjustable gate  26  serves to meter paving material  24  onto conveyor  25 . A deflector beam  27  is positioned diagonally over conveyor  25  for the purpose of deflecting paving material  24  off conveyor  25  uniformly along a length of conveyor  25 . 
     In use, conveyor  25  is positioned transverse to longitudinal axis  3  of frame  2  and above the line of sight between an operator of utility vehicle  9  and screed  10 . Gate  26  is vertically adjusted, according to the speed of conveyor  25  in the direction of arrow  28 , so that deflector beam  27  urges paving material  24  off the side of conveyor  25  in the direction of arrow  30 , at a rate such that paving material  24  forms globules  29 , thereby creating a shower of globules  29  through which the screeding action of screed  10  is observable by an operator of vehicle  9 . 
     In the laying of paved slabs, it is often desirable to reinforce the slab by incorporating into its structure a mesh or screen such as mesh  31  of FIG.  4 . Heretofore, when paving materials have been dumped or poured into the area to be paved, the pressure and weight of the dump has caused the mesh to be pressed downward and unless steps were taken to reposition the mesh it frequently was located at or near the bottom of the finished slab. By depositing paving material  24  in the form of globules  29  from a height above the surface to be paved, the kinetic energy and hydraulics of falling globules  29  causes paving material  24  to pass through mesh  31  and flow under mesh  31  before paving material  24  builds up over mesh  31  as screed  10  advances in the direction of arrow  32 . The kinetic energy of the falling globules  29  causes the aggregate in the concrete to be urged downward into the slab and the more flowable materials are urged upward, thereby consolidating the aggregate and providing a top surface that is more flowable and more readily screeded and trued. The uniform distribution and deposition of paving material achieved by distribution and deposition means  20  provides a uniform deposition so that less excess paving material  24  needs to be advanced by screed  10  in order to ensure that sufficient surplus material  24  is being advanced to fill depressions as screeding progresses in the direction of arrow  32 . 
     The uniformity of deposition achieved by distribution and deposition means  20  permits the use of a novel grooved cylindrical screed to achieve a true and uniform screeded surface. 
     Yet another embodiment is shown in FIGS. 5-7, wherein a grooved cylindrical screed  40  is illustrated. Cylindrical screed  40  has a rotational axis  41  and a cylindrical surface  42 . Formed in the surface  42  are multiple longitudinal v-shaped grooves  43 . In the most preferred embodiment, grooves  43  have a short side  44  and a long side  45  (FIG.  6 ). 
     Screed  40  is positioned transverse to longitudinal axis  3  and depends adjustably from frame  2  as shown in FIG.  7 . Screed  40  rotates in a direction according to arrow  46 , while at the same time being moved linearly along a translational direction according to arrow  47 , such that surface  40  is rotating in the translational direction  47  when surface  40  is in contact with paving material  24 . 
     Because distribution and deposition means  20  provides a uniform deposition of paving material  24  in the vicinity of cylindrical screed  40 , there is not a need to maintain any substantial surplus of paving material  24  in front of screed  40 . Further, screed  40  serves to consolidate the aggregate in paving material  24  and to spread the flowable material of paving material  24  uniformly over the screeded surface by way of v-shaped grooves  43  and to calender or smoothe the screeded surface. The resulting screeded surface is a flat, true and smooth surface of general utility quality. 
     The apparatus shown in FIG. 7 represents schematically the best mode of practicing the invention known to the inventor at the time of filing of this patent application. As shown there, screeding apparatus  1  has frame  2  shown to have adjustably depending therefrom grooved cylindrical screed  40 . Frame  2  is shown to have supported thereon distribution and deposition means  20 . Apparatus  1  is engaged with industrial vehicle  9 . 
     It should be understood that the embodiments of the invention disclosed above are enabling so that one skilled in the art can make and use the disclosed invention without undue experimentation. However, the invention admits within its scope numerous variations and a large variety of guides, adjustments and controls can be employed in practicing the invention without departing from the scope of the invention. To disclose the variations and additions that are within the scope of the invention would greatly multiply the drawings and claims and cause the specification to become prolix. Therefore, the scope of this invention should not be limited to the embodiments disclosed herein. Rather, the scope of the invention should only be limited by the scope of the appended claims and all equivalents thereto that would be made apparent to one skilled in the art. The disclosures of the cited references throughout the application are hereby incorporated by reference herein.