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BACKGROUND 
     The present disclosure generally relates to a high speed snowblower. More specifically, the present disclosure relates to a high speed runway snowblower that includes a pair of augers positioned on opposite sides of a center impeller that allows the snowblower to remove snow from a paved surface, such as a roadway or runway at relatively high speeds. 
     High speed snowblowers are particularly useful in clearing long stretches of pavement, such as an airport runway. In a typical application, multiple plows or rotating brooms are used to direct snow toward the side of a runway. A snowblowing machine is then used to move the piled snow away from the runway and onto the infield of the airfield. 
     Presently, plows and brooms can be operated at speeds much higher than the speed at which currently available truck-mounted snowblowers can remove the snow from the runway. Thus, the snowblowing equipment is the limiting factor for the amount of time needed to remove snow from a runway. 
     SUMMARY 
     The present disclosure generally relates to a snowblower for removing snow from paved surfaces, such as roads, or runways. The snowblower of the present disclosure includes a snowblower assembly having a pair of rotating side augers that direct snow toward a center impeller. The center impeller rotates and draws snow into a volute assembly where it is thrown into and through a discharge chute. The forward motion of the snowblower vehicle helps to feed snow into the snowblower housing. 
     The snowblower assembly includes a snowblower housing that defines an open interior defined at a top end by an upper hood extending between a pair of sidewalls. The upper hood defines the top edge of the snowblower housing and extends from a leading edge to a trailing edge. When installed on the snowblower assembly, the upper hood of the present disclosure decreases in height from the trailing edge to the leading edge to provide enhanced visibility for the driver of the vehicle to which the snowblower assembly is mounted. 
     Each of the side augers is driven by a hydrostatic drive motor. In accordance with the disclosure, the hydrostatic drive motor for each of the side augers is positioned outside of the open interior defined by the snowblower housing and thus above the upper hood. With the hydrostatic drive motors for each of the side augers positioned outside of the open interior of the snowblower housing, the motors cannot interfere with or otherwise obstruct snow as it is processed within the snowblower housing. 
     The lower leading edge of the snowblower housing is recessed relative to the sidewall edges and the upper leading edge of the snowblower housing such that the blades of the center, rotating impeller, and the side augers extend past the lower leading edge. The recessed lower leading edge aids in preventing a buildup of snow in front of the rotating impeller and the rotating side augers. 
     The center impeller is designed to have blade tips that each extend past the lower leading edge of the snowblower housing. The extending blade tips aid in gathering snow that may otherwise accumulate in front of the snowblower housing during use of the snowblower assembly. 
     Since the impeller blades are designed to extend past the lower leading edge, each of the side augers positioned within the snowblower housing are specifically designed to include tapered auger blades that have a width that decreases from a lower end to an upper end. The tapered blade on each of the side augers prevents the impeller blades from contacting the auger blades during operation. 
     In order to prevent the buildup of snow within the snowblower housing, the opposite sidewalls are designed having a lower sidewall edge that is recessed from the upper leading edge of the snowblower housing. The recessed lower sidewall edge prevents the buildup of snow within the snowblower housing in front of the rotating side augers. The lower sidewall edge is generally aligned with the side augers to prevent the buildup of snow on the sides of the snowblower housing as compared to prior art snowblower assemblies. 
     In accordance with one embodiment of the disclosure, each of the sidewalls of the snowblower housing can include a side plate extension. The side plate extension is selectively extendable past the recessed lower sidewall edge in order to entrap a greater volume of snow within the snowblower housing. The side plate extension allows the user to selectively increase the volume of snow that can be contained within the snowblower housing. The use of the side plate extensions aids in entrapping snow when the snowblower assembly is used with relatively dry, low density snow while allowing the user to retract the side plate extensions when the snowblower assembly is used with relatively wet, high density snow. Preferably, the pair of side plate extensions can be extended independently relative to each other such that one or both of the side plate extensions could be in either the retracted position or the extended position. 
     Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate the best mode presently contemplated of carrying out the disclosure. In the drawings: 
         FIG. 1  is a perspective view of a truck including a truck-mounted snowblower assembly of the present disclosure: 
         FIG. 2  is a side view of the truck and snowblower assembly; 
         FIG. 3  is a front perspective view of the snowblower assembly removed from the truck; 
         FIG. 4  is a front view of the snowblower assembly; 
         FIG. 5  is a side view of the snowblower assembly; 
         FIG. 6  is a bottom view of the snowblower assembly; 
         FIG. 7  is a section view of the snowblower assembly; 
         FIG. 8  is a view taken along line  8 - 8  of  FIG. 4 ; 
         FIG. 9  is a view taken along line  9 - 9  of  FIG. 4 ; 
         FIG. 10  is a front perspective view of an alternate embodiment of the snowblower assembly including adjustable side plates; 
         FIG. 11  is a side view of the alternate embodiment showing the side plates in a retracted position; 
         FIG. 12  is a side view of the alternate embodiment illustrating the extension of the side plates to an extended position; and 
         FIG. 13  is magnified view illustrating a sealing assembly. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of a snowblower  10  that includes a high speed snowblower assembly  12  mounted to the front end of a vehicle or truck  14 . The vehicle  14  includes a cab  16  positioned above the snowblower assembly  12  such that the driver of the vehicle  14  can view the pavement being cleared of snow. As illustrated in  FIG. 2 , the cab  16  is positioned at the front end of the vehicle  14  to provide the operator with the adequate viewing position to direct the snowblower  10  as needed. 
     The snowblower assembly  12  is mounted to the front end  18  of the vehicle  14  through a mechanical linkage  20  that allows the operator of the vehicle to lift the snowblower assembly  12  off of the ground when desired. The snowblower assembly  12  includes a pair of caster wheels  22  and a front, lower leading edge  30  of the snowblower assembly. The height of the front, lower leading edge  30  is adjustable through adjustments to the caster wheels  22 . 
     Referring back to  FIG. 1 , the snowblower assembly  12  includes a snowblower housing  24  that creates an open interior  25  defined by a pair of sidewalls  26 , a curved upper hood  28  that defines an upper leading edge  44  and the shaped lower leading edge  30 . The lower leading edge  30  directs snow from the ground into the open interior  25  of the snowblower housing  24  while the upper leading edge  44  defines the internal volume of the snowblower housing  24 . In the embodiment shown in  FIG. 1 , the sidewalls  26  define the width of a clearing path for the snowblower  10 . In the embodiment shown in  FIG. 1 , the clearing path is 118 inches, although other widths are contemplated. 
     As illustrated in  FIGS. 1 and 3 , a pair of side augers  32  are positioned inward of each of the sidewalls  26 . The pair of side augers  32  each rotate in opposite directions to direct snow toward the center of the snowblower assembly  12 . 
     As shown in  FIG. 3 , the snowblower assembly  12  further includes a rotating impeller  34  having a diameter of 82 inches. The impeller  34  extends through a back wall  35  of the snowblower housing  24  and rotates within open interior  25  of the snowblower assembly  12  and directs a flow of snow out of a discharge chute  36 . Referring back to  FIG. 1 , the discharge chute  36  forms part of a volute assembly  38 . As shown by the arrow in  FIG. 3 , the volute assembly  38  is rotatable to adjust the position of the discharge chute  36 . The position of the discharge chute  36  can be adjusted to direct snow to either side of the snowblower vehicle at various angles relative to the snowblower  10 . 
     Referring to  FIG. 4 , the impeller  34  includes four blades  40  that collect the snow being cleared and throw the snow into and through the discharge chute  36  and away from the snowblower  10 . Although only four impeller blades  40  are shown on the impeller  34 , the impeller could also include five blades in an alternate configuration. 
     Referring now to  FIG. 3 , each of the rotating side augers  32  includes a separate drive motor  42  used to rotate the auger  32 . The separate drive motors  42  rotate the augers  32  using a supply of hydraulic fluid provided to the respective drive motor  42  through a supply line from a power source on the vehicle. The power source used to drive the augers  32  is separate from the power source used to rotate the impeller  34 . In this manner, the drive force created by the motors  42  does not draw power from the drive force required to rotate the impeller  34 , unlike prior art systems in which the power used to rotate the augers  32  was taken from the same power source used to rotate the impeller  34 . A hydraulic fluid return line returns the hydraulic fluid to the truck. 
     As shown in  FIG. 5 , the upper hood  28  of the snowblower housing  24  generally extends from an upper leading edge  44  to a trailing edge  46 . As illustrated in  FIG. 4 , the height of the trailing edge  46  above the ground is greater than the height of the leading edge  44  such that the upper hood  28  slopes downwardly from the trailing edge  46  to the leading edge  44 . As can be understood in  FIG. 2 , the sloped upper hood  28  provides enhanced visibility for the operator of the vehicle  14  positioned in the cab  16 . Since the upper hood  28  slopes downwardly from the trailing edge  46  to the leading edge  44 , the operator of the cab is provided with increased visibility of the pavement being cleared of snow as compared to an embodiment in which the leading edge  44  is at the same height as the trailing edge  46 . The height of the trailing edge  46  must be at least as high as the top edge of the impeller  34 , as can be seen in  FIG. 4 . The impeller  34  of the illustrated embodiment has a diameter of 82 inches, which is much larger than prior snowblowers. The increased diameter of the impeller increases the height of the trailing edge  46  as compared to prior snowblowers. Thus, since the height of the trailing edge  46  is fixed, the height of the leading edge  44  is decreased to provide enhanced visibility for the operator. 
     Referring now to  FIG. 7 , the impeller  34  is mounted to a center driveshaft  49  that extends into a planetary gear reduction unit  50 . The planetary gear reduction unit  50  is received by a propeller shaft assembly at the front end of the vehicle (not shown) and receives power from an auxiliary diesel engine mounted on the vehicle. The auxiliary diesel engine mounted on the vehicle operates to only drive the impeller  34  through the driveshaft  49 , planetary gear reduction unit  50 , propeller shaft assembly, and integrated power take off/two speed transfer case assembly. As described previously, the vertical auger drive motors  42  are each hydrostatic motors that receive pressurized hydraulic fluid from the diesel engine which drives the chassis of the vehicle  14 . Thus, the power source used to drive each of the augers  32  is separate from the power source used to rotate the impeller  34 . 
     Referring now to  FIG. 3 , the lower leading edge  30  of the snowblower housing is defined by a cutting edge  52  that extends between the sidewalk  26  of the snowblower housing  24 . The cutting edge  52  directs snow upward and into the open interior  25  of snowblower housing  24 . The shape of the leading edge  30  helps to direct snow toward the rotating impeller  34 . 
     As illustrated in  FIG. 4 , each of the hydrostatic drive motors  42  are located above the upper hood  28  such that the drive motors  42  are positioned away from the open interior  25  of the snowblower housing  24  which receives snow being removed from the pavement. Each of the hydrostatic drive motors  42  receives hydraulic fluid through a pressurized hydraulic supply line such that the vertical side augers  32  are rotated to direct snow toward the center impeller  34 . In the embodiment illustrated in  FIG. 4 , each of the chive motors  42  are mounted to a support block  48  that extends above the outer surface of the upper hood  28 . Each of the support blocks  48  provides a secure point of attachment for the drive motor  42  such that the drive motor  42  can be positioned outside of the open interior  25 . 
     As illustrated in  FIG. 5 , the snowblower assembly  12  includes a pair of attachment hooks  56  that allow the entire snowblower assembly  12  to be supported on the front end of the operating vehicle  14 . The gear reduction unit  50  interacts with a drive assembly of the vehicle to provide the motive force to rotate the center impeller, as described. 
     Referring now to  FIG. 3 , inside the snowblower housing the back wall  35  extends between the auger  32  and the rotating impeller  34 . The back wall  35  is angled toward the impeller  34  to further direct snow toward the rotating impeller  34 . 
       FIGS. 4 and 7  illustrate the pair of side augers  32  that each are independently rotatable by one of the drive motors  42 . Each of the side augers  32  includes a center shaft  64  that rotatably extends between the upper hood  28  and a bottom wall of the snowblower housing  24 . The center shaft  64  is generally divided into an upper portion  66  and a lower portion  68 . The upper portion  66  includes an auger blade  70  while the lower portion  68  includes an auger blade  72 . The upper auger blade  70  and the lower auger blade  72  have different configurations and orientations such that the upper portion  66  and the lower portion  68  of the side augers  32  perform different functions. 
     Specifically, the lower auger blade  72  is configured such that rotation of the side auger causes the lower auger blade  72  to direct snow slightly upward and toward the center of the open interior  25  for discharge by the rotating impeller  34 . The upper auger blades  70  have a different configuration and are designed to fling snow toward the center of the open interior and away from the upper hood  28 . The function of both the upper and lower auger blades  70 ,  72  is to direct snow away from the sidewalls  26  and toward the center of the open interior  25 . Further, both of the auger blades  70 ,  72  are configured to direct snow toward the rotating impeller for discharge. Since the snowblower assembly  12  of the present disclosure is typically used in clearing large runways, it is important for all of the snow from the runway to be removed during a single pass of the snowblower. Thus, the pair of rotating side augers  32  functions to direct snow that may not initially be removed by the rotating impeller  34  back into contact with the rotating impeller for ultimate removal. 
     As illustrated in  FIGS. 3 and 6 , each of the impeller blades  34  extends away from a conically shaped back plate  80  to a blade tip  82 . As can best be seen in  FIG. 6 , the snowblower housing  24  of the present disclosure is specifically designed such that the lower leading edge  30  is recessed well behind the upper leading edge  44  that is part of the upper hood  28 . Specifically, the blade tips  82  extend forward from the most recessed portion of the lower leading edge  30  by a distance A shown in  FIG. 6 . The lower leading edge  30  is designed to be behind the blade tips  82  by the distance A to ensure that the impeller blades gather and process the snow prior to the snow coming into contact with the lower leading edge  30 . The recessed lower leading edge  30  increases the volume of snow that can be processed by the snowblower assembly and is especially useful when clearing relatively wet, high density snow that would otherwise have a tendency to build up on and in front of the lower leading edge  30  if it were not recessed. For this reason, the lower leading edge  30  has been designed to be recessed behind both the impeller blades  34  as well as behind the auger blades of each of the side augers  32 . 
     In the embodiments shown in  FIGS. 3 and 6 , each of the impeller blades includes an additional pre-cutter knife  86  mounted to the outside face of the impeller blades that is used to further aid in cutting snow before the snow is gathered and processed by the inside face of the impeller blades. The pre-cutter knives are particularly useful in breaking down relatively wet, high density, hard-packed, or frozen snow. The pre-cutter knives  86  are mounted to the outside face of the impeller blades in a staggered position. Specifically, two opposite pre-cutter knives are positioned near the leading tip, along the top edge, of the impeller blades  82 , and two opposite pre-cutter knives  86  are positioned further away from the leading tip, along the bottom edge, of the impeller blades  82 . By staggering the position of the pre-cutter knives, the pre-cutter knives  86  work at two different heights from the pavement surface as the impeller rotates. That is, the pre-cutter knives  86  positioned further away from the leading tip, along the bottom edge, of the impeller blades handle snow near the pavement surface as the impeller rotates, while the pre-cutter knives positioned near the leading tip, along the top edge, of the impeller blades handle snow several inches higher than the other pre-cutter knives as the impeller rotates. In an alternative configuration, each of the pre-cutter knives  86  may be positioned away from the leading tip of the impeller blades  82 , along the bottom edge of the respective impeller blades. 
     The sidewalls  26  of the snowblower assembly have been designed to further enhance the effectiveness of the side augers  32 , especially in processing relatively wet, high density snow. As illustrated in  FIG. 5 , each of the sidewalls  26  has been designed to include a lower sidewall edge  88  that is recessed from an upper sidewall edge  90 . The recessed configuration of the lower sidewall edge  88  relative to the upper sidewall edge  90  works to limit the accumulation of snow in the corners of the snowblower assembly, that is, the area directly in front of the side augers  32 . The accumulation of snow limits the effectiveness of the side augers and impedes the flow of snow into contact with the center rotating impeller. The upper sidewall edge  90 , as shown in  FIG. 5 , protrudes out slightly past the leading edge  44  of the hood  28  to help retain snow within the snowblower housing  24  as it is processed by the rotating impeller. 
     As illustrated in  FIG. 6 , the rotating center impeller has multiple impeller blades  40  that extend outwardly in the direction of movement of the snowblower relative to the recessed lower leading edge  30 . The extended configuration of the impeller blades  40  cause each of the impeller blades to rotate very close to the side augers  32 , as illustrated in  FIG. 4 . Since each of the impeller blades  40  have been extended to maximize the volume of snow that can be processed during operation, in accordance with the present disclosure, the lower auger blades  72  of the pair of side augers  32  have been designed to have a tapered configuration. Specifically, the width of the auger blade  72  extending from the center shaft  64  to the outer edge  92  decreases from the lower end  94  to the upper end  96 . Thus, as the auger blade  72  vertically approaches the widest portion of the impeller  34 , the width of the blade  72  decreases to prevent contact between the rotating auger blade  72  and the impeller blades  40 . 
       FIG. 9  illustrates a cross section taken through the side auger  32  that illustrates the tapered shape of the auger blade  72  from the lower end  94  towards the upper end. The tapered configuration of the auger blade  72  allows the side auger to be used with the impeller  34  shown in  FIG. 4  having impeller blades  40  that extend further from the back wall. 
       FIG. 8  illustrates the configuration of the upper auger blades  70  formed on the upper portion of the side auger. The auger blade  70  also decreases from a top end  98  to a lower end. Once again, the tapered configuration of the auger blade  70  prevents contact with the rotating impeller blades. 
     As described previously with reference to  FIG. 5 , the snowblower assembly  12  of the present disclosure has been designed having sidewalls  26  including a removed portion near the lower end that defines a recessed lower sidewall edge  88 . The recessed lower sidewall edge  88  has proven to be particularly useful when utilizing the snowblower assembly with relatively wet, high density snow. However, when the snowblower assembly  24  is used with relatively dry, low density snow, it is desired to provide as complete of an enclosure as possible to entrap the light weight snow within the snowblower housing  24 . 
     In accordance with the present disclosure, the snowblower housing  24  has been designed including a pair of retractable side plate extensions  100 , as shown in  FIGS. 10-12 . Each of the side plate extensions  100  is a plate-like member having a leading edge  102 . The side plate extension  100  is connected to a drive member, such as a hydraulic cylinder  104 . The hydraulic cylinder  104  is connected to a supply of hydraulic fluid such that the cylinder can be actuated to both extend and retract a piston rod  106 . When the piston rod  106  is extended, the leading edge  102  of the side plate extension  100  extends past the upper sidewall edge  90  to further entrap snow within the snowblower housing. Likewise, when the snowblower housing is used with wet, high density snow, the piston rod  106  is retracted, as shown in  FIG. 11 , to position the leading edge  102  behind the upper sidewall edge  90  as illustrated in  FIG. 11 . 
     It is contemplated that a side plate extension  100  could be positioned on one or both sides of the snowblower assembly  12 . In a preferred embodiment, each side plate extension  100  can be separately extended depending upon the user requirements. As an example, in certain situations, the operator of the snowblower may wish to only extend one of the two side plate extensions  100  depending upon the snow removal requirements. In such an embodiment, the user could extend one of the side plate extensions  100  while allowing the other, opposite side plate extension to remain in its retracted position. 
     In addition to the pair of retractable side plate extensions  100 , the embodiment of the snowblower housing shown in  FIGS. 10-12  can be configured to include a cowl assembly  120  that is mounted to the upper hood  28 . The cowl assembly  120  extends past the leading edge of the upper hood  28  to prevent snow from leaving the blower housing  24  and blowing upward directly into the windshield of the truck used to propel the blower assembly. The cowl assembly  120  has been found to be particularly useful when the blower assembly is used to remove very slushy, wet snow. 
     As illustrated in  FIG. 11 , the cowl assembly  120  includes an extending cowl  122  that is attached to the upper hood  28  through a series of connectors  124 . The cowl  122  generally conforms to the curvature of the upper hood  28  and extends from a rear edge  126  to an outer edge  128 . As can be seen in  FIG. 11 , the outer edge  128  extends past the leading edge  44  of the upper hood  28 . As illustrated in  FIG. 10 , the outer edge  128  is generally curved such that the outer edge  128  extends furthest from the upper hood  28  at its mid-portion while the opposite ends  129  of the outer edge  128  come into contact with the upper hood  28 . 
     As illustrated in  FIGS. 10 and 11 , a deflector shield  130  is attached to the outer edge  128  of the cowl  122  by a second series of connectors  132 . The deflector shield  130  extends in a generally vertical direction and aids in deflecting slush and snow back into the blower housing. 
     As illustrated in  FIGS. 10-12 , the cowl assembly  120  extends the upper hood  28  away from the vehicle such that the blower assembly can better contain very wet/slushy snow that may otherwise be deflected upward and over the leading edge of the upper hood  28  and into the vehicle windshield. Although the cowl assembly  120  is particularly useful when moving wet/slushy snow, the cowl assembly  120  will also help contain relatively dry snow that has a tendency to blow up over the top of the hood and into the vehicle windshield. 
     Although side plate extensions  100  and the cowl assembly  120  are both shown in the embodiment of  FIGS. 10-12 , it should be understood that the side plate extensions and/or the cowl assembly  120  could be removed from the snowblower housing while operating within the scope of the present disclosure. 
     Referring now to  FIG. 13 , dining use of the snowblower assembly of the present disclosure in high snow environments, the high volume of snow moving within the interior defined by the snowblower assembly has been able to pass between the point of connection between the snowblower hood  28  and the volute assembly  38 , as illustrated in  FIG. 13 . When the snowblower is moving at a relatively high speed, the snow passing through the seam formed between the upper hood  28  and the volute assembly  38  can create visibility problems. To solve this problem, the assembly of the present disclosure includes a snow containment gasket  108 . As illustrated in  FIG. 13 , the gasket includes a lower bead  110  connected to an attachment portion  112 . The attachment portion  112  is secured to the snowblower assembly through a series of connectors  114 . The bead  110  prevents snow from passing through the seam  116  and thus increases the visibility for the operator. Although the gasket is shown in the embodiment of  FIG. 13 , it should be understood that the gasket could be removed while operating within the scope of the present disclosure. 
     In an alternative configuration, a rolled steel strip may be welded to the rim of the round opening at the rear of the snowblower housing  24 . The rolled steel strip serves to overlap the seam formed between the snowblower housing  24  and the volute assembly  38  such that snow or slush is prevented from passing between the open area between the snowblower housing and the volute assembly. 
     As described, the speed of movement of the snowblower and the shape of the bottom section of the snowblower enclosure is such that the snow is directed from the pavement surface to the impeller  34  located at the rear of the snowblower housing  24 . Likewise, the snow that enters the snowblower housing  24  on opposite sides of the impeller  34  is directed slightly upward and toward the center of the snowblower housing  24  by the side augers  32 , where the snow is ingested by the impeller  34 . Since the snow is handled by both the side augers  32  and the center impeller  34 , some turbulence is created, and a certain amount of residual snow that does not immediately exit the snowblower enclosure through the volute assembly  38  and discharge chute  36  may otherwise be thrown out the front or sides of the snowblower enclosure. 
     Specifically, as the snowblower vehicle moves in a forward direction on a snow-filled runway, there is a natural tendency for some of the snow to otherwise get pushed to the sides of the snowblower assembly. In addition, a certain amount of snow being handled by the side augers and the center impeller has a tendency to be pushed forward and out of the snowblower housing. The pair of side frame extensions  74  function to increase the physical volume of the snow that can be held within the open interior  25  of the snowblower housing to keep snow contained within the snowblower housing to be processed by the rotating impeller. As described above, the upper hood  28  and the side frame extensions  74  work together to contain snow within the interior  25  of the snowblower housing while the snowblower is traveling in a forward direction, thereby increasing overall performance and reducing the amount of residual snow that is left on the runway surface during the snow removal operation.

Summary:
A snowblower assembly for removing snow from a paved surface, such as roadways and airport runways. The snowblower assembly includes a snowblower assembly that defines an open interior that encloses a pair of rotating side augers and a rotating impeller. The snowblower housing includes a lower leading edge that is recessed behind the blade tips of the rotating impeller. The sidewalls of the snowblower housing each include a recessed lower sidewall edge to reduce the buildup of snow within the snowblower housing. A side plate extension is mounted to each of the sidewalls to modify the volume of the open interior defined by the snowblower housing to accommodate different types of snow.