Patent Publication Number: US-7712232-B2

Title: Concentric axis snow blower attachment

Description:
TECHNICAL FIELD 
   The present invention is a snow blower attachment adapted to be attached to a powering vehicle. More particularly, the snow blower attachment of the present invention is adapted to be mounted on a skid steer vehicle, a compact tractor, or the like. 
   BACKGROUND OF THE INVENTION 
   Skid steer vehicles and other vehicles having similar function typically have a number of attachments that may be mounted on the vehicle for performing a variety of tasks. Unlike tractors, which typically have attachments mounted on the rear of the tractor, skid steer type vehicles typically have the attachment mounted on the front of the vehicle where it is much more convenient for the operator sitting in a cab to view the working attachment in front of him. 
   In the past, snow blower attachments have been mounted on skid steer type vehicles. In most cases, the snow blower attachments were originally designed to be mounted at the rear of a tractor. The method of mounting at the rear of a tractor is known as a three point hitch, having two lower links that are spaced apart and generally oriented in a V shape and an upper, centrally disposed link. The links are typically two to three feet in length. A three point hitch necessarily spaces the attachment significantly rearward of the tractor. When such attachments are adapted for use with skid steer type vehicles, the adaptation of the three point hitch necessarily places the attachment well in front of the skid steer type vehicle. Such placement impairs the ability of the operator to see immediately in front of the attachment and makes the skid steer vehicle and attachment as a unit unduly long, thereby impairing operation in close quarters. 
   Typically, snow blowers have a transverse auger. The auger may have opposed flighting on either side of the center point of the auger. Rotation of the auger then tends to pull the snow toward the center of the auger. A large fan is typically mounted behind the auger. The axis of the fan is typically orthogonally disposed with respect to the axis of the auger. The fan, being a rather large diameter increases the height the of the snow blower attachment, thereby further impairing the ability of the operator in a skid steer type vehicle to see immediately in front of the snow blower attachment. 
   Further, with a centrally mounted fan, the chute through which the snow is ejected is usually positioned immediately above the large fan housing in the center of the snow blower attachment. Such disposition of the chute again further impairs the ability of the operator in the cab of the skid steer type vehicle or other vehicle to view objects that may be in the front of the snow blower attachment. 
   Accordingly, there is a need in the industry for a snow blower attachment for attaching to skid steer type vehicles and other vehicles that is mounted close to the vehicle and is compact in size with minimal height in order to minimize the impairment of the operator&#39;s vision forward of the snow blower attachment. 
   SUMMARY OF THE INVENTION 
   The concentric axis snow blower attachment of the present invention substantially meets the aforementioned needs of the industry. The chassis assembly of the snow blower attachment includes “quik-tach” plates mounted directly on the chassis. Such plates permit the snow blower attachment to be quickly and easily mounted directly to the lifting arms of the skid steer type vehicle, thereby minimizing the forward projection of the snow blower attachment relative to the skid steer type vehicle. No attaching points normally associated with three point hitch links are included. As noted above, such attaching points typically act to undesirably extend the snow blower attachment from the vehicle. It should be noted however, that, where desired, the snow blower attachment of the present invention could readily be modified for use with three point hitch links. 
   While snow blowers having the fan and auger mounted on a single axis are known, they typically power both the fan and the auger from a single source. The source in the past has usually been a PTO shaft and gearing was used to drive the fan and auger at different speeds. While the speeds of rotation were different, both the fan and the auger were dependent on the single motive source. The present invention advantageously independently drives the fan and the auger and concentrically axially mounts the fan and auger. 
   Further, the auger and the fan of the snow blower attachment are concentric axially disposed. Such disposition minimizes the height of the snow blower attachment over which the operator must sight in order to see in front of the snow blower attachment. Additionally, the fan is at one end of the auger. This places the chute assembly close to an end margin of the snow blower attachment. Accordingly, the chute assembly is to the side of the field of view necessary for the operator in the cab of the skid steer type vehicle to view in front of the snow blower attachment. 
   Other efficiencies are apparent in the design for the concentric axis snow blower attachment of the present invention. The chute assembly is rotatable through approximately 270° to allow the snow to be discharged back down along the right side of the skid steer type vehicle or transversely across the front of the skid steer type vehicle. Further, a rounded inlet wall directs the snow to be ejected from the fan blades through the round chute assembly. The transition is from round inlet to round chute as opposed to square inlet to round opening to square chute typically in prior art snow blowers. The prior art configuration is much more prone to plugging. The configuration of the present invention minimizes the possibility of moist, heavy snow packing and jamming the chute assembly. The noted configuration of the present invention further keeps the chute low, preferably at about a 45 degree angle relative to the top of the snow blower attachment body, advantageously minimizing the discharge path of the blown snow 
   The hub of the auger is formed of a tube having a significant diameter, on the order of 40 percent of the diameter of the auger flighting. The relatively large hub tends to control the amount of snow that is admitted into the snow blower attachment for discharge therefrom and advantageously strengthens the auger. This further minimizes the possibility of jamming the snow blower attachment with moist heavy snow. 
   Finally, both the auger and the fan are reversible in their directions of rotation in order to assist in the ejection of any debris that may have been caught in either the auger or the fan. In practice, a reduction of power in the reverse direction is automatically provided to minimize the possibility of auger damage when an object is jammed in the auger. Further, in either direction of rotation, hydraulic pressure in the system is automatically bled of in the event of a stoppage of either or both the fan and the auger. 
   The present invention is a snow blower attachment, the snow blower attachment includes a concentric axis fan and auger, the fan and auger being independently powered by respective motors and being axially operably coupled for support and for independent rotation of the fan and auger. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front elevation view of the snow blower attachment mounted to a skid steer vehicle; 
       FIG. 2  is a left perspective view of the snow blower attachment mounted to a skid steer vehicle; 
       FIG. 3  is a front elevation view of the snow blower attachment mounted to a skid steer vehicle; 
       FIG. 4  is a left front perspective view of the snow blower attachment with the covers removed and no auger motor; 
       FIG. 5  is a right rear perspective view of the snow blower attachment with the covers removed; 
       FIG. 6  is a left front perspective view of the snow blower attachment chassis assembly; 
       FIG. 7  is front quarter perspective of the chassis assembly of the snow blower attachment; 
       FIG. 8  is rear quarter perspective of the chassis assembly of the snow blower attachment; 
       FIG. 9  is perspective view of a motor housing; 
       FIG. 10  is a perspective view of the fan; 
       FIG. 11  is an elevational view of the fan; 
       FIG. 12  is a perspective view of a hydraulic motor for driving with the fan or the auger; 
       FIG. 13  is front elevational view of the auger; 
       FIG. 14  is perspective view of the auger; 
       FIG. 15  is an elevational view of the right side margin of the auger; 
       FIG. 16  is an elevational view of the left side margin of the auger; and 
       FIG. 17  is a schematic of the hydraulic assembly. 
   

   DETAILED DESCRIPTION OF THE DRAWINGS 
   The concentric axis snow blower attachment of the present invention is shown generally at  10  in the figures. The snow blower attachment  10  is particularly adapted to be attached to a skid steer vehicle  20 , however the snow blower attachment  10  may be used on other vehicles as well, such as compact tractors and the like. 
   An exemplary skid steer vehicle is shown generally at  20  in the figures. The skid steer  20  has a chassis  22  with a centrally mounted cab  24 . Two lift arms  26  are included with one lift arm  26  disposed along either side the cab  24  and typically being hinged toward the rear portion of the skid steer vehicle  20 . 
   Pivot actuators  28  are mounted to each of the lift arms  26 . A pivot point  30  is disposed at the very bottom forward end of the each of the lift arms  26 . Such a pivot point  30  permits an attachment (including the present attachment  10 ) that is coupled to the skid steer  20  to be pivoted relative to the lift arms  26 , as well as being raised by the arms  26 . 
   A certain skid steer  20  may have two different types of electrical connectors  32   a ,  32   b . The newer type electrical connector  32  is a seven pin connector that is a connection with the computer on board the skid steer  20 . Communications are typically multiplexed over the pins to thumb controls on the ends of the two motion control levers that control operation of the skid steer vehicle  20 . The older type electrical connector  32  has significantly more contacts. Other skid steer vehicles may have other communication arrangements than the exemplary skid steer  20 . Such arrangements are also compatible with the snow blower attachment  10 . 
   The skid steer  20  has two hydraulic connectors  34   a ,  34   b . The operator in the cab  24  can command either one of the hydraulic connectors  34   a ,  34   b  to be the output of high pressure hydraulic fluid. The return is then the other of the selected hydraulic connector  34   a ,  34   b  for hydraulic output. By this means, the rotation and rotational direction of both the fan and the auger are readily controlled. A smaller sump (or case) hydraulic connector  36  is also provided. In a hydraulic motor, there is always some leakage into the sump (case) of the hydraulic motor. Such hydraulic fluid is typically at significantly lower (nearly zero) pressure and may be returned to the skid steer  20  via the sump hydraulic connector  36 . 
   The snow blower attachment  10  of the present invention has four major subcomponents: chassis assembly  40 , auger/fan assembly  42 , chute assembly  44 , and hydraulic assembly  46 . 
   Turning to the first subcomponent of the snow blower attachment  10 , the chassis assembly  40  is preferably formed of steel plate. The chassis assembly  40  has a generally rectangular cross section with a front opening  49  for admitting snow thereto ( FIGS. 1-8 ). 
   The chassis assembly  40  has a back  50  that is generally rectangular in shape. Two quik-tach plates  52  are spaced apart and fixedly mounted to the back  50 . The quik-tach plates  52  selectively mate directly to cab operated hydraulic mounting devices mounted to the ends of the lift arms  26  of the skid steer vehicle  20 , for hands-off attaching of the snow blower attachment  10  to skid steer  20 . The quik-tach plates  52  also mount to non cab operated mounting devices that require external manual operation. The quik-tach plates  52  are known in the industry. 
   In an embodiment, the chassis assembly  40  has a generally rectangular top  54 . A protective bridge  56  is centrally disposed on the top  54 . By bridging the bridge  56 , a protected space beneath the bridge  56  is defined for the passage of hydraulic tubes therethrough. 
   The top  54  further includes a circular outlet opening  58  disposed proximate an end margin (the right end margin, when viewed from the cab  24 ) of the top  54 . A plurality of mounting bores  60  are defined on the top  54  for mounting a portion of the hydraulic assembly  46  to the top  54 . A deflector  62  spans the full length of the top  54  and is mounted at the forward edge of the top  54  by a plurality of hinges  64 . When in the depicted down position of  FIGS. 1 and 2 , a first portion of the deflector  62  is flush with the top  54 . The deflector  62  is held in this disposition by its own weight. The leading portion of the deflector  62  is bent downwards to define a deflector lip  66 . As an excessive amount of snow is ingested into the snow blower attachment  10 , the deflector  62  will rise upon the snow. Such action is clearly visible to the operator and gives an indication to the operator to the skid steer vehicle  20  that the operator might want to reduce forward speed, thereby reducing snow intake and preventing the snow blower attachment  10  from being impacted with snow. 
   The chassis assembly  40  further includes a pair of opposed endplates  68 . In an embodiment, each of the endplates  68  includes a generally square opening  70  through which respective hydraulic motors (described in greater detail below) for independently driving the auger  96  and the fan  98  are inserted. A round or other shape for the opening  70  would work equally well. A plurality of bores  72  are defined peripheral to the opening  70  for effecting the mounting of the respective hydraulic motors therein. A plurality of bolts  74  projects outward from the respective endplates  68 . 
   The forward portion of the respective endplates  68  is comprised of a leading lip  76  that is bent outward with respect to the chassis assembly  40  for capturing a portion of the snow that lies outward of the chassis assembly  40 , as the snow blower attachment  10  is advanced into the snow. A generally horizontal bumper  78  projects outward from the respective endplates  68 . In practice, the bumper  78  could either be a portion of the respective endplate  68  or be the end margin of the bottom  84 , discussed in greater detail below. 
   A cover  80  is provided with each of the endplates  68 . The cover  80  is designed to provide protection to the hydraulic lines coupled to the respective hydraulic motors driving the auger and fan. Each of the covers  80  has a plurality of slots  82  defined therein for mating with the bolts  74 . 
   The bottom  84  has a generally rectangular shape. A replaceable blade  85  is mounted at the leading edge  86  of the bottom  84 . 
   In the embodiment of  FIG. 4 , the blade  85 , and leading edge  86  are optionally hinged to the forward portion of the bottom  84  by a hinge  88 . A spring  90  at either side margin of the bottom  84  (the right spring  90  being depicted) is coupled at one end to the respective endplates  68  and at the other end to the hinged blade  85  and leading edge  86 . When an obstruction, such as a sewer casing or the like, is impacted by the snow blower attachment  10 , the blade  85  and leading edge  86  rotate downward about the hinge  88 , thereby minimizing damage to the blade  85 . Further, this prevents a jarring impact to the snow blower attachment  10  and the skid steer  20 , as well as to the operator. When the obstruction is passed, the hinged blade  85  and leading edge  86  is resettable and may be brought back into the depicted flush disposition by the springs  90  and/or in conjunction with backing motion of the skid steer vehicle  20 . 
   Preferably, a plurality of rounding facets  92  are welded proximate the juncture of the back  50  and the bottom  84  to conform more closely to the outside diameter of the flighting of the auger  96 . Preferably, a plurality of generally upright rounding facets  95  are welded proximate the juncture of the back  50  and the right end plate  68  (see  FIG. 5 ) to provide a rounded inlet for the snow being forced upward to the chute assembly  44  by the fan  98 . A generally semi-circular fan shroud  94  is disposed at the right side of the chassis assembly  40  spanning the distance between the top  54  and the bottom  84 . 
   The second subcomponent of the snow blower attachment  10  is the auger/fan assembly  42 . The auger/fan assembly  42  includes the auger  96  and a fan  98 . It should be understood that the greater portion of the work performed in blowing snow is performed by the fan  98  as compared to the auger  96 , particularly if the it is sought to propel the snow great distances from the snow blower attachment  10 . Accordingly, it is desirable that the fan  98  rotate at a considerably greater speed than the auger  96 . Although the auger  96  and the fan  98  are concentric axially mounted they are independently driven by two hydraulic motors, one motor  106  dedicated to driving the auger  96  and the other motor  126  dedicated to driving the fan  98 . The fact that the auger  96  and fan  98  are concentric axially mounted, yet independently driven, is one of the features that sets the snow blower attachment  10  apart from the prior art. 
   The auger  96  has a tubular hub  100 , preferably formed of tubular steel. The diameter of the hub  100  is chosen to be substantial in size (four to twelve inches, preferably) in order to provide a barrier to an inordinate amount of snow entering the snow blower attachment  10 . By this means, the snow blower attachment  10  is much less prone to be clogged, especially by wet, heavy snow. The auger  96  is disposed well within the envelope defined by the chassis assembly  40 , especially proximate the front opening  49 , in order to protect the auger from damage. It is more cost effective to let the chassis assembly  40 , as compared to either auger  96  or the fan  98 , bear the brunt of any impacts with foreign objects. 
   Flighting  102  is disposed on the outer margin of the hub  100 . The flighting  102  is unidirectional, as can be seen in  FIGS. 1 ,  4 ,  13 , and  14 , in that rotation of the auger  96  in the direction of the arrow  104  of  FIG. 4  tends to move snow left (L) to right (R) across the face of the snow blower attachment  10 , thereby feeding the snow to the fan  98 . The flighting  102  is spiral wound and spaced apart from the hub  100  and supported in this disposition by support pieces  013  that extend from the hub  100  to the flighting  102 . 
   Generally, the hub  100  diameter is between 20 and 60 percent of the flighting  102  diameter and is more preferably 40 percent of the flighting  102  diameter. Preferably, the hub is 8 inches in diameter and the flighting is 18 inches in diameter. 
   The auger  96  has a right end plate  105 , as depicted in  FIG. 15 . The right end plate  105  is generally co-extensive with the end margin of the hub  100 . A short tubular, inward directed hub  107  is disposed at the center of the end plate  105 . Hub  107  has a cylindrical inner margin  113 . 
   As depicted in  FIG. 16 , a left end plate  109  is recessed from the left end margin of the hub  100 . By recessing the end plate  109 , a tubular space inside the hub  100  is formed in which the motor  106  is disposed. The inner margin of the short tubular hub  111  is splined and is matable to splines  117  on the drive shaft  119  of the motor  106 , as depicted in  FIG. 12 . It should be noted that in a preferred embodiment, the motors  106 ,  126  are identical. The auger  96  is therefore both supported and rotationally driven at the left margin of the auger  96  by the motor  106 . 
   The hydraulic auger motor  106  is inserted through the opening  70  of the endplate  68  and fixedly coupled thereto by means of a motor mount  212 , as depicted in  FIG. 9 . The description that follows also applies to a similar motor mount  212  used to secure the fan motor  126 . The motor mount  212  has a generally rectangular end plate  213  that has an opening  214  defined therein that corresponds to the opening  70  in the respective end plates  68 . Four bores  216  are in registry with the four bores  72  in the endplates  68 . Bolts may be passed through the respective bores  216 ,  72  for securing the motor mount  212  to a respective end plate  68 . A pair of supports that are orthogonally disposed relative to the end plate  213  are fixedly coupled to the end plate  213  and fixedly coupled to a spaced apart motor mounting plate  220 . The motor mounting plate  220  has a centrally disposed bore defined therein that the drive shaft  119  of the motor  106 ,  126  can project through. A pair of bores  224  may be brought into registry with the bores  226  of the motor  106 ,  126  ( FIG. 12 ), so that bolts passed therethrough may secure a respective motor  106 ,  126  to a respective motor mount  212 . 
   Turning to the fan  98  as depicted in  FIGS. 10 and 11 , the fan  98  includes a relatively large diameter hub  122 . The hub  122  is preferably formed of tubular steel and is preferably  8  inches in diameter, thereby defining a motor opening  125  therein. The hub  122  is closed at a leftward directed end by and end plate  230 . A splined hub  232  is centrally disposed in the endplate  230 . Splines  234  form an interior margin of the hub  232  and are compatible (matable) with the splines  117  of the motor  126 . The hub  232  has a cylindrical outer margin  233 . The hub  232  is preferably inserted into the space defined by the inner margin  113  of the hub  107  of the auger  96  to support the right end of the auger  96 . A bearing or bushing (not shown) may be interposed between the margins  233  and  113 . There is no central axle as such supporting both the fan  98  and the auger  96 . The fan  98  and the auger  96  are mutually supportive, eliminating the need for such an axle. 
   The hub  122  is affixed to a relatively larger diameter end plate  236  disposed at a rightward directed end. The end plate  236  has a bore  238  defined therein that is substantially of the same diameter as the hub  122 . The hub  122  is affixed to the end plate  236  proximate the margin of the bore  238 . 
   A plurality of substantially rectangular blades  124  are included, each being affixed at an end margin to the hub  122  and at an orthogonal end margin to the end plate  236 . The blades  124  are preferably flat and are disposed in a generally radial manner with respect to the hub  122  with a slight bend  240  at a distal end. 
   The hydraulic fan motor  126  is inserted through the opening  70  in the endplate  68  and affixed to the endplate  68  by the motor mount  212 , as noted above. The hydraulic fan motor  126  is thereby disposed within the motor opening  124  defined in the hub  122  and coupled to a motor mount  212  as noted above. The splines  117  of the motor  126  may be mated to the splines  234  of the fan  98  for directly rotatably driving the fan  98 . Other means of coupling the hydraulic fan motor  126  and the motor mount  212  may be employed, including, for example, a shaft and key, a square drive and a hex drive. 
   Turning now to the third subcomponent of the snow blower attachment  10 , as depicted in  FIGS. 1 ,  2 ,  4 , and  5 . The chute assembly  44  is disposed at the right hand side of the snow blower attachment  10  immediately above and in communication with the fan  98 . The chute assembly  44  includes a rotatable turret  140 , a chute  142 , and a deflector  144 . The turret  140  has a plate  146  that is affixed to a relatively short tube  147 . The tube  147  is disposed in the outlet opening  58  of the chassis assembly  40 , and the plate  146  rests on the top  54  adjacent to the outlet opening  58 . It is understood that the turret  140  is readily rotatable relative to the chassis assembly  40 . To effect such rotation, the plate  146  has a toothed edge that is formed on the outside margin of the plate  146  and extends around the plate  146  for in excessive of 270 degrees. Other means of rotation could as well be used including, for example, a chain or cable drive. 
   A motor  150  (either a hydraulic motor or a suitable electric motor) is mounted on the back  50  of the chassis assembly  40 . The hydraulic configuration is be discussed below. The hydraulic motor  150  has a rotatable sprocket  152  that is engaged with the tooth edge  148 . The hydraulic motor  150  is a bidirectional motor so that the chute assembly  44  can be rotated in either direction as desired. The chute assembly  44  is rotatable between a first position in which snow is being discharged leftwards substantially parallel with the longitudinal axis of the auger  96  to a second disposition in which the chute assembly  44  is discharging rearward, substantially along side the right side of the skid steer vehicle  20  in a direction that is substantially transverse to the longitudinal axis of the auger  96 . Thus, the chute assembly  44  is rotatable through an arc of substantially 270°. 
   The turret  140  has a short upward directed tubular neck  154  that directs the chute  142  at an angle of between 30 and 85 degrees relative to the top  54  of the chassis assembly  40 . The chute  142  is fixedly coupled to the neck  154  preferably at an angle of substantially 45 degrees relative to the top  54  of the chassis assembly  40 . An alternative chute  142  could be employed when the discharged snow is to be loaded in a truck. Such chute  142  has an extended neck portion that is disposed at about 90 degrees relative to the top  54  of the chassis assembly  40 . Such chute  142  has a deflector  144  that may be positioned at about 90 degrees relative to the longitudinal axis of the neck for ready discharge of the snow into the box of a truck. 
   The chute  142  has a pair of opposed, spaced apart flat sides  156  that are connected to a rounded back  158  that is designed to receive snow from the rounded facets  93 . Preferably the rounded back  158  is formed by a series of relatively shallow angle adjacent tapering bends. The flat sides  156  define a front opening  160  of the chute  142 . 
   The deflector (or cap)  144  is pivotally mounted to the chute  142 . The deflector  144  includes a pair of opposed flat sides  162  coupled to a flat back  164 , thereby defining a front opening  168  for the discharge of snow. The deflector  144  is affixed to the chute  142  by means of a pivot mount  170 . The pivot mount  170  may be a bolt  171  passed through each of the flat sides  162  and through a respective flat side  156  of the chute  142 . 
   A longitudinally extending actuator  172  is disposed alongside the chute  142  and is coupled at a first end by a chute mount  174  to the chute  142  and at a second end by a deflector mount  176  to the deflector  144 . The longitudinally extending actuator  172  may be hydraulic or electric. The depicted embodiment is of a hydraulic cylinder  172 . The hydraulic cylinder  172  is a double acting cylinder and provides that the angle of the deflector  144  relative to the chute  142  can be varied through an arc of about 90 degrees. 
   The fourth subcomponent of the snow blower attachment  10  is the hydraulic assembly  46 , as depicted in  FIGS. 1-3 . The hydraulic assembly  46  includes a valve assembly  178  (depicted schematically in  FIG. 17 ) and electric control  180  that is disposed beneath a cover  181  on the left hand side of the top  54  of the chassis assembly  40 . A pair of auger motor tubes  182  emerges from the left hand side of the valve assembly  178  and is coupled to the auger motor  106 . A third smaller tube emerges from the left hand side of the valve assembly  178  and is connected to the auger motor  106 . This tube is the sump (or case) tube  183 . Similarly, a pair of fan motor tubes  184  and a sump tube  185  emerges from the right hand side of the valve assembly  178  and is coupled to the fan motor  126 . Additionally, a pair of turret actuation tubes  186  also emerges from the right hand side of the valve assembly  178  and is connected to the hydraulic motor  150 . 
   A pair of deflector actuation hoses  188  emerges from the rear of the valve assembly  178  and is connected to the hydraulic cylinder  172 . Three additional hoses emerge from the rear of the valve assembly  178 . The two larger of the hoses are the input/return hoses  190 . The third smaller hose is the sump return hose  192 . Each of the two input/return hoses  190  and the return sump hose  192  are coupled to respective quick connectors  194  for mating of the hydraulic system of the skid steer vehicle  20 . 
   The valve assembly  178  is a multi use device that may be used to control a plurality of operations, especially where there is a feed function (auger in this specific case) and an operating function (fan in this specific case). Such operation may include a chipper/shredder operation, for example, where branches are automatically fed to a powered chipper. The valve assembly  178  as used in the present application is depicted in  FIG. 17 . Generally, each component that is supplied by the valve assembly  178  in the schematic includes an A and a B port. Thus, the fan A port is designated FA and the fan B port is designated FB. Likewise, the auger A port is designated AA and the auger B port is designated AB in the schematic. This notation is used for these and other components below. It should be noted that the operations right of the line  250  may as well be preformed as well by electric motors, as detailed above. In this case, this portion of the hydraulic schematic of  FIG. 17  may be eliminated. 
   Proceeding to the description of the valve assembly  178 , at the outset it should be noted that G 1 -G 3  are extra taps that are used for pressure testing but presently play no part in the operation of the valve assembly  178 . Hydraulic pressure in from the skid steer vehicle  20  is at P in    252  and return is at R  254 . With a known skid steer vehicle  20 , the pressure in is at approximately 3400 psi and the return pressure is about 200-400 psi. Pressure in travels to P in    252  from the skid steer vehicle  20  upward in the schematic to fan port FA, drives the fan  98 , and exits the fan  98  at fan port FB. The fluid then travels downward to intersection  256 , rightward to intersection  258  and upward to auger port AA. This fluid is at a pressure of about 600-800 psi in the present example. The hydraulic fluid drives the auger  96  and exits the auger  96  at auger port AB and returns downward to return R  254  and thence back to the skid steer vehicle  20  at about 200-400 psi. 
   It is known that the skid steer vehicle  20  has a relief valve that actuates at approximately something slightly greater than the 3400 psi maximum pressure in the present example. When this occurs, all hydraulic pressure generated by the skid steer vehicle  20  is dumped and the fan  98  and auger  96  receive hydraulic pressure, but no hydraulic flow. This causes the fan  98  and auger  96  to stop rotating and is wasteful of energy, both undesirable situations. To prevent the skid steer vehicle  20  from dumping pressure, it is important that the valve assembly  178  ensure that the pressure at which pressure relief occurs in the skid steer vehicle  20  is not approached. Accordingly, a counter balance valve (CNB) at  260  intersects the line from P in    252  to FA at intersection  256 . The 3400 psi fluid is passed thru orifice OR 1  at  262  to the CNB  260 . The CNB  260  is adjustable and is usually set at about 500 psi less than the pressure at P in    252 , in this case, about 2900 psi. Therefore, any pressure above 2900 psi at P in    252  is bled off and dumped to the return R  252 . The hydraulic fluid that is bled off passes through intersection  264 , check valve  266 , and intersection to the return at  254 . The fan  98  then receives a maximum of 2900 psi hydraulic fluid and the maximum pressure in the system is then also limited to 2900 psi, thereby minimizing the chance that the skid steer vehicle  20  relief pressure is ever reached. 
   Reverse operation of the fan  96  and auger  98  is also possible, in which case the input pressure is supplied at the return R  254  and P in    252  becomes the drain or return. Reverse operation is described in more detail below. At this point, it is sufficient to say that in reverse operation the high pressure (3400 psi, in this example) at R  254  is prevented from flowing to the CNB  260  by the check valve  266 . 
   As noted above, when the auger  96  gets jammed, either with impacted snow or with a foreign object, it is desirable to reverse the flow of hydraulic fluid and to thereby reverse the rotational directions of the fan  98  and auger  96  to expel the impacted snow or eject a foreign object. Since the auger  96  may be in a nearly locked condition, it is desirable to minimize the hydraulic pressure that the auger  96  sees. A mere reversing of the hydraulic flow would port 3400 psi hydraulic fluid from R  254  to the auger port AB. With a locked auger  96 , such pressure could damage the auger  96 . To eliminate this possibility, a bi-directional relief (BI-R) valve  270  is interposed between the lines leading to the auger ports AA and AB at intersections  258  and  272  respectively. In this disposition, the BI-R  270  is available to provide pressure relief at a selected variable pressure (usually about 1000 psi) to the auger  96  by bleeding pressure from the intersection  272  to the intersection  258  and thence to return at P in    252 . It should be noted that the BI-R  270  works similarly in the forward direction to bleed off pressure in the event of a stoppage of either or both the auger  96  and fan  98 . 
   While the primary use of the BI-R  270  is during reverse operation, the BI-R  270  is also available to relieve pressure in the forward operation, especially as the auger  96  becomes jammed. Such jamming could cause a pressure spike were the system not protected by the BI-R. As the Auger  96  becomes jammed during forward operations, hydraulic pressure is bled off through the BI-R  270  by bleeding pressure from the intersection  258 , through the BI-R  270  to intersection  272  and thence to the return at R  254 . 
   In reverse operation, the orifice OR 2   274  comes into play to limit the maximum pressure in the system. Hydraulic fluid is flowed through the orifice OR 2   274  from the intersection  280  and through the overrunning check valve  276  to the intersection  278  and thence to return at P in    252 . This permits the motion of the auger  96  to coast to a stop in the event that the hydraulic flow to the auger  96  is instantaneously shut off. Such pressure is typically limited to about 1000 psi to the auger  96  by the restricted flow through the OR 2   274 . The overrunning check valve  276  prevents flow through the above-described path during forward operations. 
   As noted above, most hydraulic motors have a sump drain or it may be referred to as a case drain. This drains away hydraulic leakage that virtually always occurs in the motor housing. The provision for this is at lines FC (fan case)  280  and AC (auger case)  282  that are joined at intersection  284  and then flow to drain D  286 . 
   Turning to the components that are right of the line  250 , there is both chute  142  rotation, having ports MA and MB, and deflector  144  (or cap) actuation, having ports CA and CB. Hydraulic fluid for actuation of chute rotation and deflector actuation is tapped off the input line to the auger  96  at intersection  258 . Such fluid flows through orifice  288 , further reducing the pressure, and thence to the ports MA and CA respectively through intersection  290 . The volume and pressure of the hydraulic fluid necessary to provide such actuation is minimal in comparison to that required to operate the fan  98  and the auger  96 . Accordingly, hydraulic fluid can be tapped of at the return line from the auger  92  at intersection  272  in order not to steal high pressure hydraulic fluid from either the fan  98  nor the auger  96 . Waste oil pressure only is then used for driving chute  142  rotation and deflector  144  (or cap) actuation. Return flow is from the respective ports MB and CB to intersection  292  and thence to drain D  286  through intersections  294  and  284 . 
   In operation, the snow blower attachment  10  is attached to the skid steer vehicle  20 , either automatically from the cab  24  or manually outside the cab  24 . The snow blower attachment  10  may be operated at any angle achievable by the lift arms  26  and the pivot actuators  28  of snow blower attachment  10 . Accordingly, the snow blower attachment  10  may be elevated by the lift arms  28  and rotated so that the front opening  49  is facing downward. The snow blower attachment  10  may then be actuated in the forward direction so that both the auger  96  and the fan  98  are rotating. The snow blower attachment  10  may then driven high into a snow bank and gradually lowered to the ground by the arms  26 , maintaining the downward orientation of the snow blower attachment  10 . The chute assembly  44  may be rotated to direct the discharged snow generally parallel to the auger axis and, in this manner the snow bank may be shaved off. 
   Alternately, the snow blower attachment  10  may be rotated such that the front opening  49  is forward directed and the snow blower attachment  10  may elevated. The skid steer vehicle  320  may then advance the snow blower attachment  10  into a snow bank and blow an upper portion of snow from the bank. The skid steer vehicle  20  may then retreat, lower the snow blower attachment  10 , and again advance into the snow bank. This may be repeated sequentially stepped down until the snow blower attachment  10  is lowered all the way to the ground and a significant portion of the bank reduced. 
   Additionally, the snow blower attachment  10  may be slightly rotated upward such that the leading edge of the snow blower attachment  10  is slightly elevated from the ground. The skid steer vehicle  20  may then be advanced blowing snow, while ensuring that any foreign obstacles on the ground are passed over. 
   It will be obvious to those skilled in the art that other embodiments in addition to the ones described herein are indicated to be within the scope and breadth of the present application. Accordingly, the applicant intends to be limited only by the claims appended hereto.