Abstract:
The disclosure relates to a device and method of use of a plow back blade for snow removal. The plow back blade is attached to a snowplow or snow blower to assist with removing snow from areas that are otherwise difficult to access with conventional snow removal equipment. The plow back blade is rotatably attached to a snowplow blade at a pivot point. The plow back blade is engaged into a locked position as the vehicle moves in reverse to assist with the scraping of ice and packed snow from pavement. The plow back blade enters a free position as the snowplow plows in its forward position which also sharpens the plow back blade lower edge. Furthermore the plow back blade allows additional applications for snowplows and snow blowers such as dirt leveling.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The disclosure relates generally to plows and in particular the present disclosure relates to plow back blades for snow removal. 
         [0002]    The seasonal removal of snow from residential and commercial driveways and parking lots is generally the responsibility of the property owner. Property owners with relatively small surfaces often use their own or hire contractors with snow blowers to remove the snow. Property owners with large paved surfaces often use or hire snowplows for snow removal. Snowplows and snow blowers are well known in the prior art. Snow blowers are generally small self-propelled units that are powered by an engine that also drives wheels or tracks. However they may also be mounted on a small vehicle such as a pickup, ATV or tractor in a similar manner as a snowplow with the auger powered hydraulically or with a separate engine. 
         [0003]    For large residential and commercial properties, due to the need for expensive equipment that is used very infrequently, snowplowing services are often done by specialized commercial contractors. These contractors may have a significant investment in equipment that is used intermittently, infrequently and without much advanced notice during the winter season. Even though winter snowfall is relatively unpredictable, snow removal contractors only have a very limited time to remove the snow from all their clients paved areas. 
         [0004]    After a snowfall, all customers typically want their property cleaned and cleared as quickly as possible. If a contractor takes to long, the contractor will lose the customer, as the customer makes other arrangements for snow removal. Therefore, there is a relatively small window of time for a contractor keep his equipment active and producing revenue. As such, there is a tremendous advantage for efficient snow removal operations. Improvements in efficiency result in more customers being able to be handled by a given vehicle for a given snow event, directly impacting the profitability of the business. 
         [0005]    Snow removal contractors focusing on parking lots, driveways and the like, often use small vehicles such as four wheel drive pickup trucks equipped with a front mounted plow blade in their business. These vehicles are easily driven from site to site and are very efficient at pushing snow to the perimeter of driveways and parking lots while the vehicle is moving forward. 
         [0006]    However, in many situations the snow must be pulled away from obstacles, such as parked or snowed in vehicles, buildings, garages, retaining walls, parking lot islands, and loading docks. In these situations, the operator must either leave a strip of unplowed pavement next to the obstacle or try several one of several ways to remove the snow all of which are somewhat inefficient. 
         [0007]    Leaving a strip of unplowed snow around an obstacle is usually unacceptable to the customer. Doing so typically requires the contractor make a return trip to the site, which is inefficient and costly. 
         [0008]    To remove the snow from near an obstacle typically requires either the operator get out of the vehicle and manually remove the snow next to the obstacle or the operator try to scrape the snow back with the plow. 
         [0009]    Manually removing the snow with a shovel or snow blower is inefficient because it requires the driver to exit the vehicle to simply move the snow to a position where it can then be accessed with the snowplow and the snowplow has to again be used to push the shoveled snow out of the way. This is a relatively inefficient use of the operator&#39;s time since it requires extra time to manually remove the snow as well as to re-plow the pavement receiving the manually removed snow. 
         [0010]    Snowplow blades for small vehicles are designed to push snow while driving forward. The snow accumulates in front of the snowplow blade until it either spills over the top or spills off to the side. The front of a typical snowplow is often concave on its vertical surface. This is done to keep the snow from ramping up the front of the blade and overtopping the blade before it is directed off to the side. 
         [0011]    The concave vertical surface on the snowplow blade is also useful for getting underneath compacted snow and ice to provide a cleaner payment. This happens because using a concave vertical surface allows the edge of the snowplow blade to form an oblique angle of greater than 90 degrees with the pavement approaching the plow which allows the snowplow blade to get under and loosen the compacted snow and ice. 
         [0012]    Often hydraulic cylinders are used to pick the blade up as well as to angle the blade in one direction or the other. In some embodiments the blade is hinged to allow the blade to be formed into a “V” shape with the hydraulic cylinders. In some locations, this is called a Split Gull Wing. This allows the vertex or centerline of the plow to be either forward or behind the centerline of the edges of the plow. Having the edges behind the centerline allow the plow to direct snow to both sides of the vehicle. Allowing the center of the plow to be behind the edges will increase the snow carrying capacity of the plow and reduce the snow directed to the sides of the vehicle while the “V” is filling. 
         [0013]    Regardless of the embodiments described above, the snowplow blades and snow blowers are relatively inefficient at removing the snow by operating the vehicle in reverse and trying to scrape the snow back with the back surface of the snowplow blade. The concave vertical surface of the snowplow blade that is needed to clear the ice and snow from the front of the snowplow translates into a convex back surface on the snowplow blade. The convex back surface prevents efficient dragging of the snow away from objects when the snowplow is operated in reverse. In addition, dragging snow with a conventional snowplow is generally ineffective at removing any compacted snow or ice. The convex angle of approach to the snow when the vehicle is operated in the reverse direction simply allows the back of a normal blade to ride over the packed snow. Even on removal of loose snow, the angle of approach leaves a significant residual behind as the bottom of the snowplow is being dragged over and compacting the snow. Additionally, any snow that is collected behind the snowplow quickly ramps over the convex surface of the back of the snowplow. 
         [0014]    For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative snowplow blades particularly with regard to improving the plowing characteristics of a snow plow in its reverse direction. 
       SUMMARY OF THE INVENTION 
       [0015]    This disclosure is directed toward a plow back blade that is attached to a snowplow blade or a snow blower. The plow back blade is pivotably connected to the snowplow blade at a pivot point. The plow back blade is configured to not interfere with snowplow blade operation when a vehicle is traveling in a forward direction. The plow back blade is configured to engage material to be plowed when the plow is plowing in a reverse direction opposite the forward direction. 
         [0016]    Conceptually a snow blower may be envisioned as a snowplow blade with additional augers, blowers and shielding to throw the snow a distance beyond the edge of the snow blower. Thus this disclosure is relevant to snow removal generally in bi-directional operation. The invention is highly flexible and independent as to specific details as to how the snow is removed in the forward direction. Therefore this disclosure is presented largely using a snowplow as an example while also being generally relevant to snow blowers. 
         [0017]    It is an object of this invention to disclose a plow back blade that will automatically clear snow adjacent to obstructions without having to disembark a vehicle. 
         [0018]    It is an object of this invention to disclose a plow back blade that will remove ice and packed snow when the vehicle is operated in a reverse direction. 
         [0019]    It is an object of this invention to disclose a plow back blade that will reduce the snow overtopping the snowplow by operating synergistically with the snowplow blade as the vehicle operates in the reverse direction. 
         [0020]    It is an object of this invention to disclose a plow back blade that is self sharpening as the vehicle operates in its forward direction. 
         [0021]    It is an object of this invention to disclose a plow back blade will not interfere with the operation of the snowplow as the vehicle operates in its forward direction. 
         [0022]    It is an object of this invention to disclose a plow back blade that may include a hardened steel wear plate. 
         [0023]    It is an object of this invention to disclose a plow back blade that may be readily mounted on a snowplow or snow blower as an aftermarket accessory. 
         [0024]    It is an object of this invention to disclose a plow back blade that may be used to level soil. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0025]      FIG. 1  illustrates an elevational cross section plow back blade attached to a snowplow blade on a vehicle plowing in a forward direction. 
           [0026]      FIG. 2  illustrates an elevational cross section plow back blade attached to a snowplow blade on a vehicle plowing in a reverse direction. 
           [0027]      FIG. 3  is a perspective view of an embodiment of the plow back blade. 
           [0028]      FIG. 4  illustrates a hinged embodiment of a plow back blade, according to another embodiment of the disclosure. 
           [0029]      FIG. 5  is a side view showing several of the positions into which the plow back blade may be operated. 
           [0030]      FIG. 6  is an expanded view of a support arm embodiment-using fastener to hold the plow back blade in a transport position. 
           [0031]      FIG. 7  is a cross-sectional view of a scraper blade having a wear plate with a sharp edge. 
           [0032]      FIG. 8  is an elevational view of a snow blower with a plow back blade in locked position. 
           [0033]      FIG. 9  is an elevational view of a snow blower with a plow back blade in a transport position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    Referring to  FIG. 1 , a snowplow blade  100  is depicted as being attached to the front of a vehicle for plowing snow as the vehicle moves forward. A support system  110  is used to structurally attach the snowplow blade  100  to the vehicle. The support system  100  is also used to transfer forces from the snowplow blade  100  to the frame and suspension of the vehicle. A plow back blade  10  is rotatably attached to the structure of the snowplow blade  110  to provide snow removal ability as a vehicle moves in a reverse direction to allow bi-directional snow removal ability. 
         [0035]    The snowplow blade  100  is typically a steel plate having a front surface  101  and a back surface  102 . Typically the snowplow blade  100  is reinforced with a structural member  105  for example, an angle iron, channel or rectangular tubing may be added to minimize bending and deformation of the snowplow blade  100 . A plurality of structural members  105  are typically welded to the back surface  102  of the snowplow blade  100 . The snowplow blade  100  may be flat along its vertical direction, but is typically curved into a concave vertical surface. 
         [0036]    The limits of the vertical surface are generally defined by a top edge  103  and a bottom edge  104 . The bottom edge  104  is generally horizontal to substantially engage a paved surface. The top edge  103  may be generally parallel to the bottom edge  104  or it may be upwardly sloped from the center of the snowplow blade  100  to each end. A sloped top edge  103  helps prevent overtopping of the snow as the snow accumulates and is moved from an interior of the snowplow blade  100  toward an end. 
         [0037]    A support system  110  is used to transfer the weight and forces received by the snowplow blade  100  into the suspension system of the vehicle. The support system  110  may include vertical support hinge  111  as a point of rotation with a lift mechanism  115  such as a hydraulic cylinder  120  to raise and lower the plow in a vertical direction. The support system  110  may also include a horizontal support hinge  112  to provide a rotation point for one or more hydraulic cylinders  120  to rotate the plow in a horizontal direction. The snowplow blade  100  may also be hinged to allow the blade to be changed into various shapes simply by activating the hydraulic cylinders  120 . These shapes may include a straight blade that is horizontally rotatable to direct snow toward a side of the vehicle or a “V” shape so that when the vertex of the “V” is in a forward position, the snow is directed toward both sides of the vehicle, or when the vertex of the “V” is directed rearward, the snowplow blade  100  forms a hopper to enhance collection of snow in front of the front of the snowplow blade  100 . 
         [0038]    A plow back blade  10  is mounted to the snowplow blade  100  and is located between the vehicle and at least portions of the snowplow blade  100 . The plow back blade  10  includes a support arm  60  that attaches the snowplow blade  100  to a scraper blade  20  portion of the plow back blade  10 . The support arms  60  are pivotably connected to the snowplow blade  100 , preferably at a structural member  105 . Therefore the plow back blade  10  to a large extent will generally be lifted and/or positioned by the lift mechanism through the snowplow blade  100 . 
         [0039]    The scraper blade  20  may be a heavy flat bar of hardened steel having a working surface  25  facing the front of the vehicle, and a support surface  30  facing the snow plow blade  100 . The working surface  25  may be, for example, either flat or concave. In a concave embodiment, preferably the concave surface would be facing towards the vehicle. As shown in  FIG. 1 , as the vehicle moves forward, the plow back blade  10  has rotated to a free position  12  so that the scraper blade  20  is being pulled or dragged along the pavement. This dragging action may provide a self-sharpening feature to the scraper blade  20 . 
         [0040]    With reference to  FIG. 2 , the snowplow blade  100  is raised sufficiently so that snow plow blade  100  is above the pavement, and the plow back blade  10  is allowed to rotate into a substantially vertical position from the weight of the plow back blade  10 . The snowplow blade  100  is then lowered so that scraper blade  20  contacts the pavement surface. If desired, substantially the entire weight of the snowplow blade  100  may be supported by the plow back blade  10 . The reverse operation of the vehicle in cooperation with either the physical friction from the pavement and/or the accumulating weight of the snow, will rotate the plow back blade  10  toward the snowplow blade  100  until the plow back blade  10  physically contacts the snowplow blade  100  such as at a structural member  105 . The plow back blade is then in its locked position  11  held against the snowplow blade  100  by the reverse movement of the vehicle and the weight of the accumulating snow against the scraper blade  20 . 
         [0041]    Since the vertical height of the plow back blade  10  is less than the vertical height of the snow plow blade  100 , the snow may overtop the plow back blade  10 . This is usually not an issue of concern because reverse operation of the vehicle is not generally necessary to occur over any substantial distance. However, any snow that overtops the plow back blade  10  is very loose and easily captured by the back surface  102  of the snow plow blade  100 . 
         [0042]    The plow back blade  10  shown in  FIG. 3  includes a scraper blade  20  that may be integral with or attached to support arms  60 . The support arm  60  has a free end and a fixed end. By way of example, the support arms  60  shown as an angle iron may also be channel or tube with a circular or rectangular cross section. The support arm  60  may be straight or arced in either a longitudinal or lateral direction. The support arm  60  fixed end is attached to the scraper blade  20  by welding, bolting or other known means. The support arm  60  free end includes a pivot point  65  for pivotably connecting the plow back blade  10  to the structural member  105 . Examples of a pivotal connection include a pin, bolt, bearing assembly or rivet. The support arm  60  is typically pivotably attached to a structural member  105  on the back surface  102  of the snowplow blade  100  or directly to the back surface  102 , preferably at approximately the vertical midpoint of the snowplow blade  100 . 
         [0043]    The working face  25  of the scraper blade  20 , facing the vehicle, has an upper edge  21  and a lower edge  22 . The upper edge  21  position is determined by the geometry of the support system  110 . The upper edge  21  position is located so that it contacts the snowplow blade  100  at its desired locked position and can freely rotate beyond the free position  12  without interference from the support system  110 . 
         [0044]    The lower edge  22  is positioned so that the lower edge  22  is at or below the bottom edge  104  of the snowplow blade  100 . Otherwise a gap would exist and the plow back blade  10  would be unable to contact all the packed snow on the pavement. If the lower edge  22  is below the bottom edge  104  of the snowplow blade  100 , it is possible to place the entire weight of the snowplow blade  100  on the plow back blade  10  which assists with removal of ice and packed snow. Furthermore if the working surface  25  of the plow back blade is concave this is also useful for getting underneath compacted snow and ice to provide a cleaner payment. This happens because using a concave vertical surface allows the working surface  25  forms an oblique angle of greater than 90 degrees with the pavement approaching the plow back blade  25  which allows getting under and loosening the compacted snow and ice. 
         [0045]      FIG. 4  illustrates a hinged embodiment of a plow back blade suitable for use on a hinged plow that is conformable into a “V” configuration. Alternatively, two independent plow back blades  10  could be installed with the plow back blades  10  meeting in the horizontal center of the snowplow blade  100 . Also shown in  FIG. 4  is an embodiment where the scraper blade  20  includes a wear plate  35 . This allows for easy replacement and/or hard surfacing of the lower edge  22  which receives extra wear being in direct contact with the pavement. 
         [0046]      FIG. 5  is a side view showing the rotation of the plow back blade  10  about the pivot point  65  to its range of positions. A substantially horizontal position is utilized as a locked position  11  defined by the plow back blade  10  being held against the snowplow blade  100  as the vehicle travels in a reverse direction. The free position  12  allows the plow back blade  10  to loosely drag and conform to the pavement contours as the vehicle moves in a forward direction. Additionally a transport position  13  may be utilized where the plow back blade  10  is rigidly fastened out of the way when not in use. This position is useful to prevent the plow back blade from swinging when the vehicle is moving but not plowing such as when traveling between sites. 
         [0047]      FIG. 6  shows the support arm  60  held in the transport position  13  using a fastener  45  such as a bolt or pin to prevent the plow back blade  10  from swinging during vehicle movement. Alternatively, the plow back blade could be chained, pinned or otherwise clipped to the snow plow blade  100  or support system  110 . 
         [0048]      FIG. 7  shows a cross-sectional view of a scraper blade  20  having a wear plate  35  with a sharp bottom edge. The support surface  30  faces the snow plow blade  100  and is opposite the working surface  25  of the scraper blade  20 . As the vehicle operates in its forward direction a bevel is formed between the support surface  30  and the working surface  25 . This bevel is self sharpening and useful for assisting scraping of ice and snow as the vehicle moves in a reverse direction. 
         [0049]    As previously described the plow back blade  10  is also suitable for use on snow blowers  200 . Snow blowers  200  may be vehicle mounted or self propelled.  FIG. 8  is an elevational view of a self propelled snow blower  200  with an auger  210  within an auger housing  220 . The plow back blade  10  is in a locked position  11  and attached to the auger housing  220 . As shown, the lift mechanism  115  would typically be a simple mechanical linkage. 
         [0050]      FIG. 9  is an elevational view of a snow blower  200  with a plow back blade  10  in a transport position  13 . 
         [0051]    With regard to snow blowers  200  and snowplows, a feature of the invention that allows the lower edge  22  of the plow back blade  10  to be below the bottom edge  104  of the snowplow blade  100 . In this embodiment it is possible to place the entire weight of the snowplow blade  100  on the plow back blade  10 . This feature allows these machines to be used for leveling materials such as dirt, sand and gravel. This is possible because the plow back blade  10  can be easily constructed to handle these materials in a reverse direction even though it would be cost prohibitive and for impractical to utilize these devices in a forward direction on these dense materials. This would allow for example, a snow blower to used in the summer time for leveling fill on small landscaping or construction. For example, a snow blower could be used to assist filling in potholes on a gravel road or path, a use totally impractical with a conventional snow blower. 
         [0052]    Although specific embodiments of apparatuses and methods using the apparatus as an example, have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, combination, and/or sequence that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. It is to be understood that the above description is intended to be illustrative and not restrictive. 
         [0053]    Combinations of the above embodiments and other embodiments as wells as combinations and sequences of the above methods and other methods of use will be apparent to individuals possessing skill in the art upon review of the present disclosure. The scope of the claimed apparatus and methods should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.