Patent Publication Number: US-2006005434-A1

Title: Snowplow assembly

Description:
FIELD OF THE INVENTION  
      This invention relates to snow removal equipment and, more particularly, to a snowplow assembly of lightweight construction.  
     BACKGROUND OF THE INVENTION  
      Passenger vehicles have been used for sometime as a means for plowing snow by utilizing snowplow assemblies which are detachably mounted to the passenger vehicle. The passenger vehicles of choice for such plowing have included full size pickups and sport utility vehicles (“SUV&#39;s”.)  
      Efforts are underway to utilize smaller passenger vehicles for plowing snow. For example, it is desirable to be able to utilize a lightweight pickup as the vehicle for plowing snow with the detachably mountable snowplow assembly. However, conventional detachable snowplow assemblies, built for full size pickups and/or SUV&#39;s, can subject such a lightweight pickup to excessive loads due to the weight of the snowplow assembly.  
      Accordingly, it is desirable to redesign the conventional passenger vehicle mountable snowplow assembly in an effort to reduce its weight for use on lighter weight vehicles, for example lightweight pickups.  
     SUMMARY OF THE INVENTION  
      In accordance with the principles of the present invention, a snowplow assembly comprises a lift frame and A-frame operably pivotally connected together, an actuator operably connected between the lift frame and A-frame for effecting relative pivotal movement between the lift frame and A-frame and a plow blade including a blade frame, the blade frame including a tube of circular cross section, the tube operably pivotally connected to the A-frame.  
      The lift frame and A-frame can be adapted to be connected to a vehicle mount frame as a unit. The tube of the blade frame can be pivotally received by a quadrant, the quadrant operably connected to the A-frame. The snowplow assembly can further include a resilient element operable between the blade frame and A-frame normally biasing a lower edge of the plow blade forwardly; the pivotal connection of the plow blade to the A-frame in combination with the resilient element provides a trip function of the plow blade. The resilient element can be non-metallic, for elastomeric. The plow blade can also be non-metallic, for example a composite. The tube can extend substantially the width of the plow blade. The lift frame can include a pair of extensions extending away from the plow blade, and can be adapted to be received by a vehicle mount frame. The snowplow assembly can further include a pair of support stands removably secured to the lift frame. The tube can include a pair of stops which cooperate with a pair of urethane cushions on the quadrant to limit pivoting movement of the plow blade.  
      In another aspect, a snowplow assembly comprises a lift frame and an A-frame operably pivotally connected together, an actuator operably connected between the lift frame and A-frame for effecting relative pivotal movement between the lift frame and the A-frame, a plow blade operably pivotally connected to the A-frame, and a non-metallic resilient endless loop operably connected between the plow blade and A-frame; the pivotal connection of the plow blade to the A-frame in combination with the resilient loop provides a trip function of the plow blade.  
      In yet another aspect, a snowplow assembly comprises an A-frame and a plow blade including a tube of circular cross section, the tube operably pivotally connected to the A-frame.  
      In still another aspect, a snowplow assembly comprises an A-frame, a plow blade operably pivotally connected to the A-frame, and a non-metallic resilient endless loop operably connected between the plow blade and the A-frame; the pivotal connection of the plow blade to the A-frame in combination with the resilient loop provides a trip function of the plow blade.  
      In a further aspect, a snowplow assembly comprises an A-frame, a plow blade including a tube of circular cross section, the tube operably pivotally connected to the A-frame, and a non-metallic resilient endless loop operably connected between the plow blade and A-frame; the pivotal connection of the plow blade to the A-frame in combination with the resilient loop provides a trip function of the plow blade.  
      These and other advantages of the present invention will become more readily apparent during the following detailed description taken in conjunction with the drawings herein, in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS OF THE INVENTION  
       FIG. 1  is a perspective view of a snowplow assembly according to the principles of the present invention;  
       FIG. 2A  is a side view of the snowplow assembly of  FIG. 1  prior to striking an obstruction;  
       FIG. 2B  is a view similar to  FIG. 2A  but showing the trip function of the snowplow assembly caused by the blade striking an obstruction;  
       FIG. 3  is a rear perspective view of the snowplow assembly; and  
       FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 3 . 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION  
      Referring first to  FIG. 1 , there is illustrated a snowplow and mount assembly  10  according to the principles of the present invention. The assembly  10  includes a snowplow assembly  20  and a vehicle mount assembly  30 .  
      Referring to  FIGS. 1-3 , snowplow assembly  20  can include a lift frame  40 , an A-frame  50 , a quadrant  60  and a plow blade  70 . Lift frame  40  can include a pair of upwardly extending supports  402  interconnected by an upper laterally extending support  404 . Lateral extending support  404  can support a hydraulic motor  406  to supply hydraulic fluid to a hydraulic lift cylinder  408 , also supported by support  404  and connected to A-frame  50 . A pair of headlamps  410  can be supported by the upwardly extending supports  402 . Lift assembly  40  can further include a pair of rearwardly extending arms.  412  which are adapted to be removably secured to mount frame assembly  30 , as will be described below. Lift assembly  40  can further include a pair of support stands  414  each of which includes a leg  416 , foot  418  and height adjustment mechanism  420 . Each of the stands  414  can be removably secured to the lift frame  40  by slipping mechanism  420  onto tongue  422  which can be secured to vertical member  402 . A lower laterally extending support  424  can interconnect arms  412 .  
      A-frame  50  has a rear end which can be pivotally connected to arms  412  of lift assembly  40  via pivot pins or bolts  502 , and has a forward end which can be pivotally connected to the quadrant  60  via pivot bolt  504 . Pivot pins  502  permit pivoting of the A-frame  50 , quadrant  60  and blade  70  about a generally horizontal, transverse axis, whereas pivot bolt  504  permits quadrant  60  and blade  70  to be pivot relative to A-frame  50  about a generally vertical axis. A-frame  50  can further include a pair of hydraulic cylinders  506  operably connected between the A-frame  50  and quadrant  60  for pivoting the quadrant  60  and blade  70  about the generally vertical axis which is defined by pivot bolt  504 .  
      Quadrant  60  can include a first semi-circular structure  602  and a second semi-circular structure  604  which journal or pivotally support a circular cross section tube  702  on the rear side of blade  70 . Tube  702  can be formed as part of a framework  704  to which blade  70  is mounted, can be continuous and have a length extending substantially the width of the blade  70 , can be about 2-2.75 inches in outer diameter and can be spaced away from the blade  70  about 0.75 inch. Framework  704  can include ribs  706  having lightening cuts therethrough to reduce the weight thereof, as well as holes therethrough through which to install tube  702 . Tube  702  and ribs  706  can be carbon steel; tube  702  can be secured to ribs  706  as by welding. Blade  70  can be attached to framework  704  with suitable fasteners (not shown): A pair of stops  708  and  710  can be fixedly secured to tube  702 . Stops  708  and  710  limit the angle of pivoting of blade  70  during the trip function ( FIGS. 2A and 2B .) Stops  708  and  710  can cooperate with urethane cushions  606  and  608 , mounted to quadrant  60  with pivot bolt  504 , to limit pivoting of blade  704 . Blade  70  can be of lightweight composite construction.  
      Quadrant  60  can include a pair of arms  610 ,  612  on each lateral side thereof, each pair supporting a bar  614 . Blade assembly  70  can include a cross bar  712  in between two of the ribs  706  of the blade frame  704 . A pair of resilient endless elastomeric loops or bands  714  can be installed to bar  712  and to bars  614  to provide a restoring force to restore blade  70  to the position shown in  FIG. 2A  after being tripped by an obstacle, as shown in  FIG. 2B .  
      Referring back to  FIG. 1 , vehicle mount assembly  30  includes a mount frame  302  adapted to be secured to a vehicle (phantom) having a pair of sockets  304  each formed by inboard  306  and outboard  308  plates. Sockets  304  accept arms  412  of lift frame  40 . The lift frame  40 , A-frame  50 , quadrant  60  and plow blade  70  are connectable to the mount frame  302  as a unit. Arms  412  are inserted into sockets  304 . Notches  428  in the ends of arms  412  each receive a pin (not shown) fixed within each socket  304 . Removable pins  310  can then pass through holes in alignment plate  312  and through holes in both socket  304  forming plates  306 ,  308 , as well as through holes  426  in arms  412  securing lift frame  40  and hence A-frame  50 , quadrant  60  and plow blade  70  to mount frame  302 .  
      The lightweight nature of elastomeric bands  714 , as compared to metallic tension or compression springs, along with the composite construction of blade  70 , aid in reducing the weight of the snowplow assembly  20 . Further, while providing a trip function of the blade  70 , tube  702  also provides torsional stiffness for composite blade  70 .  
      If desired, tube  702  can be employed to torsionally stiffen blade  70  without providing a trip function for blade  70 . In that case, tube  702  need not be circular in cross-section; most any hollow, closed cross-section tube such as those having square, rectangular, etc. cross-sections would suffice. For that matter, the cross-section need not be constant the length of the tube  702 .  
      Those skilled in the art will readily recognize numerous adaptations and modifications which can be made to the present invention which will result in an improved snowplow assembly, yet all of which will fall within the spirit and scope of the present invention as defined in the following claims. Accordingly, the invention is to be limited only by the scope of the following claims and their equivalents.