PLOW FOR MOTOR GRADER

Abstract: A plow for a motor grader is provided with forwardly pivotable panel members (42, 44) along opposite end portions (32, 34) of the moldboard (30) which can lie flat against the moldboard (30) in conventional plow configuration disposi­ tion or be extended forwardly therefrom to define plow retaining structure by means of which the plow retains and carries forward removed grade debris without leaving significant windrow residue.

Description: The grading operations which can be carried out with a motor grader are diverse. The grader, for example can be employed to cut down and level a slope to provide a generally flat tract. It can be used to cut a road along a desired course or it can be used for such a simple task as transporting material from an accumulated stock from one location to another. This versatility of the motor grader stems from the construction thereof which allows a wide three-dimensional positioning of the grading plow. The plow, carried on a drawbar structure, can be rotated 360 degrees in a horizontal plane, it can be tilted forwardly or rearwardly relative to a horizontal plane (grade) and can along with the framing on which it is mounted, be tilted (relative to said plane) to the left and to the right to dispose the plow at an angle to the horizontal. Further, the plow can be translated or slid relative to its mounting. There are however certain limitations in the use of a motor grader fitted with known types of plows. For example, in cutting a road it is not possible to cut or grade the road surface and downwardly inclining run-off surfaces commonly required at each of the road sides in the same grading pass. Thus, the grader must following a road surface cut, be returned to a starting point, the plow angled to correspond to a run-off cut disposition and then driven forwardly in a new cutting pass to grade the run-off. Another limitation is encountered where grading in multiple passes over an expansive area is carried out. In such operations, the plow usually will be angled to the right or left of the long axis of the grader. As the grader makes cutting passes, removed grade material travels from the toe end to the heel of the plow and sustantial quantity of material passes off at the heel leaving a windrow thereof along the cutting pass margin. This windrow must then be carried forward in the next pass but the windrow spillage process repeats itself. Thus extra passes of the grader must be made if ultimately a cut material is to be removed from initial to final tract locations. In grading along a curb line where the plow will be angled to the right or left, spillover of material at the toe end of the plow to the rear side of the plow can occur as a cascading deposit onto the curbing frame requiring that extra labor be used to clear debris from the frame. Also, a conventional plow has only limited movement possibility when grading the environs of manhole frames and sewer boxes adjacent curb lines necessitating unneeded and multiple grader movements in and around such structures. In addition to the foregoing, the conventional plow cannot present a configuration thereof which can retain and carry forwardly any significant quantity of cut grade material. Plows which can be folded to define material holding space are known. For example, bulldozer and snow plow blades comprised of two equal length blade halves pivoted together can be angled about the pivot from a flat front face plow disposition to a V-configuration to form a retention space with the folded halves. However, such retention space has limited volume and such plow cannot be angled or tilted in any of the many other plow configurations commonly used and/or required in a motor grading operation. US Patent No. 3,477,151, US Patent No. 4,099,578 and European Patent Publication No. EP-A-7000 each disclose a plow having auxiliary blades pivotally attached to opposite ends of a conventional plow. However, in each of these prior art plows, severe loadings are encountered at the pivot locations and on the hydraulic cylinders leading to a greater likelihood of failure. According to the present invention, there is provided a plow for a motor grader or the like, comprising: an elongated moldboard having as a unitary component along its length opposite moldboard end sections and a central section between said end sections; and a panel member pivoted at one of its ends to said moldboard and being swingable with respect to the moldboard from a first position to a second position wherein it is disposed at an angle with said moldboard; characterised in that said panel member is pivoted proximate the juncture of one moldboard end section and said central section and rests in said first position against said one moldboard end section in covering contact therewith to define a substantially conventional plow configuration along said one moldboard end section and defines in said second position with the moldboard central section an enclosure boundary defining a plow retention space suitable for retaining graded material on the plow as it is moved in a grading pass over a surface being graded. In an embodiment of the present invention a plow which is mountable on a conventional motor grader drawbar frame comprises an elongated moldboard of, e.g., arcuate cross section, and constituted of a unitary component having opposite moldboard end sections and a central section intervening these end sections or portions. Panel members of elongate character are carried on each of the moldboard end sections, the panel members being pivoted at an end of each to the moldboard proximate the junctures of the moldboard central section with the moldboard end sections or portions. The panel members each can locate in a first disposition wherein they lie flat nested against the associated moldboard end section closely snubbed in conformable contact therewith. In this configuration, the panel members function in cooperation with the moldboard central section in the same manner as a conventional plow so that if the plow be angled to make a grading cut, one panel represents the toe end of the plow and the other the heel. Material removed in the cutting pass travels from the toe to the heel in the usual fashion. The panel members are on the other hand, movable forwardly on the moldboard from first disposition to a second held or locked position or disposition wherein they dispose at an acute angle with the moldboard end section, such panel member movement being effected with suitable power means such as hydraulic cylinder units and further such that one panel member can be moved independently of the other. This capability of so disposing the panel members alters the basic plow geometry to configure it to define a plow bebris or material retention space wherein cut material can collect and be retained as the grader moves forwardly in a grading pass. This reduces and in some instances depending on the depth of cut being taken can eliminate formation of material spill-off windrows at the end of the plow. Since more removed material is carried forward in a pass there is ultimately a reduction in the time and number of grader passes involved in a particular grading task. In the requirement for cutting a crowned road or a gully, the moldboard can be tilted forwardly or rearwardly relative to the vertical and crosswise to grader travel and the two panels be extended to second position. In such configurations, the panel lower cutting edges will be situated either below or above the moldboard central section cutting edge. In this manner, a forward pass travel of the grader will result in either a road with downwardly directed run-offs or a gully with upwardly inclining side walls being cut at the same time, again increasing the productivity attending the grading operation. When grading at a curb is required, the plow will be inclined relative to the longitudinal axis of the motor grader and then the panel member at the toe end of the plow extended to second position. The thus extended toe end panel presents a sharper angle of attack to the grade surface and results in more positive impelling of removed material along the moldboard reducing the likelihood that spillover of material at the toe end of the plow can occur and deposit on the curb frame. The mounting of the panel members in one embodiment can be effected with a pair of pivot blocks fixed to the moldboard at each of the junctures of the moldboard end sections with the central section. A cooperating pair of hinge blocks is carried on each panel member and one of the hinge blocks in each of these last-mentioned blocks includes a crank extension passing to the rear of the moldboard so that such crank extension can be connected to the movable rod of a hydraulic cylinder unit. To facilitate bridging flow of debris moving from the moldboard central section onto an adjacent panel member when that panel member is in folded first position, a fairing plate extending transversely of the moldboard is fixed thereto adjacent the panel pivoting location, the fairing plate inclining from the moldboard front face surface outwardly to substantial merger with the panel member front face. Other objects and advantages of the invention will be detailed in the description to be given below. The invention will be further described with reference to the accompanying drawings in which: Fig. 1 is a side elevational view of a motor grader fitted with an improved plow made in accordance with the invention; Fig. 2 is a perspective view of the plow showing one panel member in second and the other in first positions; Fig. 3 is a top plan view of the Figure 2 plow showing illustrating the locations at which the free ends of the panel members locate relative to corresponding ends of the moldboard in the respective panel positions; Fig. 4 is a fragmentary front elevational view on enlarged scale depicting the hinge mounting of a panel member to the moldboard; Fig. 5 is a top plan showing of Figure 4; Fig. 6 is a diagrammatic depiction of use of the plow in material carrying configuration wherein prior produced windrows created incident grading are eliminated by use of the plow without further windrow creation in a carrying pass; Fig. 7 is a diagrammatic depiction showing use of the plow in a grading operation at a curb line; Fig. 8 is a view similar to Figure 7 showing special adaptability for working in and around manhole frames, sewer boxes and like upstanding obstructions which can be present in a grading course; Fig. 8a is a view depicting another positioning of the plow in the Figure 8 operation; Fig. 9 is a diagrammatic depiction of a road grading operation wherein the plow is employed to cut the road surface and water run-off paths at each side of the road in the same pass; Fig. 9a is a side elevational view of Figure 9 illustrating forward tilting of the plow to produce the cutting edge dispositions required to effect simultaneous cutting shown in Figure 9; Figs. 10 and 10a correspond to Figures 9 and 9a except the plow has been tilted rearwardly to cut a gully with upwardly inclined side walls simultaneously in the cutting pass; and Fig 11 is a fragmentary plan view illustrating a further utility of the plow as a lifting device to remove large objects such as boulders from a grading area. Throughout the following description, like reference numerals are used to denote like parts in the drawings. Referring to Figure 1, motor grader 10 is a known type including forward main chassis frame 12 supported on front wheels 14 and to which is mounted a drawbar assembly 16 in the usual manner,i.e., the drawbar can pivot toward and away from the viewer about a longitudinal axis of the grader and it also can pivot up and down about the pivot of the drawbar forward connection to the grader,i.e., it can pivot clockwise and counterclockwise as viewed in Figure 1. This pivoting can be effected in combination of movements of hydraulic cylinder units 18,20 carried on chassis frame 12 and connected with the drawbar assembly. The drawbar assembly also includes a rotatable ring member 22 to which is mounted a grading plow shown generally at 24, the ring member having an internal gear formed therein which is in mesh with a fixed pinion(not shown) driven by hydraulic motor 26. Thus, the ring member and hence the plow, can be rotated 360 degrees about the horizontal or surface to be graded to position the plow in a desired work position. In addition, the hydraulic cylinder units 18,20 can be operated to provide additional specific plow orientation as may be required for a given grading requirement depending on whether the grading is of a slope, relatively flat land space etc. The foregoing motor grader construction is well known to those skilled in the art. Further, a hydraulic cylinder unit as shown at 28 can be used to forwardly and rearwardly tilt the plow in known manner. The plow 24 is of the construction shown in Figs. 2-5 and continuing reference will be had to these Figures now in describing the plow. The plow includes an elongated arcuate cross section moldboard 30, the moldboard having two opposite end sections or portions 32,34 intervened by and joined in unitary structure with a central moldboard section 36. Panel members 42,44 are carried on the respective moldboard end sections 32,34 and are of elongate character, the panel members each being pivoted at one end to the moldboard a distance from a respective moldboard end,i.e., proximate the junctures of the respective end sections with central section 36. The panel members each have first positions in which they nest closely snubbed or (in the case of arcuate cross-section members) conformably folded against the associated moldboard end sections in contact therewith, and they have lengths which are greater than the moldboard end sections so that when in first position the other end of each panel extends some distance longitudinally (e.g., 20.3 to 30.5 cm.) beyond a corresponding end of the moldboard, this being evident from the positioning of panel member 44 as seen in Figures 2 and 3. The panel members can be moved forwardly of the moldboard to selected second positions of each, the extreme range of the forwardly located second positions (up to 45 degrees with the moldboard end sections) being exemplified with respect to the showing of panel member 42 in Figures 2 and 3. In the extreme second positions of the panel members as well as any intermediate forward position, the tip ends of the panel members are still situate some distance longitudinally of a corresponding end edge of the moldboard insuring that it is always the panel member tip end and not the tip end of the moldboard which lies closely adjacent any vertical barrier, e.g., a curb frame when grading at a curb line. The panel members 42,44 are pivoted to the moldboard with hinge members fitted to each. Thus a pair of hinge pieces 46,48 are rigidly connected as by welding to the moldboard proximate the junctures of the moldboard end sections and the central section. Companion hinge pieces 46a and 48a are carried on the respective panel members and pivot pins 50 pass through the hinge pieces. One of the hinge pieces connected to the panel members, i.e., each hinge piece 46a carries a crank extension 49 which passes to the rear side of the moldboard where the extension is fixed to the rod 54 of a hydraulic cylinder unit mounted on the rear of the moldboard. The hydraulic cylinder units 56 are operable independently one of the other from the hydraulic system of the motor grader. In the depicted embodiment, it will be seen that the cylinder unit rods 54 are fully retracted to extend the panel members forwardly and the rods are extended from their associated cylinders to retract the panel members against the moldboard end sections, the cylinder units being suitably controlled in known manner to hold the panel members in any given or selected second position. The hinge members 46,48,46a and 48a are tapered and otherwise smoothly contoured to reduce the obstruction same present to material flow along the moldboard when ,e.g., the plow is used in the manner of a conventional plow, i.e., when the panel members are retracted. Since the panel members in retracted position present a forwardly positioned structure relative to the moldboard, it is desirable that smooth flow of material moving from the moldboard central section toward the heel of the plow be provided. For this purpose fairing plates 58 are fitted to the moldboard adjacent the pivoted ends of the panel members. These fairing members extending transversely of the moldboard have inclined faces which thicken from minimum dimension at the moldboard face to maximum thickness corresponding substantially with that of the panel members where they confront in juxtaposition with the panel member end edges. The moldboard 30 also can carry in the end sections thereof, stress relieving pins 60 which are fixed to the moldboard and can, e.g., taper forwardly so that these pin members cooperate with companion openings 62 formed in the panel members. When the panel members are retracted the pins locate closely in the openings and this arrangement allows the pins to absorb any shock transmitted to the hinges, cylinder units, mountings etc., when the plow is used in making grading cuts of hard surface material and wherein the panel members will be retracted. Grading cuts can of course be made with the panel members extended, the limitation in that instance being the depth of cut and the type of surface involved. As will be seen in Figure 2, the moldboard central section is fitted at the lower edge with a readily removable and replaceable cutting edge 64. Similar cutting edges 66 are provided on the panel members 42,44 and the panel members also carry vertical cutting edges 68 at their tip end transverse margins. As noted above, the plow 24 can be used in convetional fashion wherein both panel members 42,44 will be in first positions of each. It can be used in other configurations wherein one or both of these panel members are extended. Some of these utilizations will be discussed below and with reference to Figures 6-11 Figure 6 shows how the plow 24 is used to clean up windrows 70 on a site which has already been graded and incident such grading, one or more of such windrows 70 result consequent spillage of graded material off the heel of the grading plow. for this operation, the two panel members 42,44 will be extended forwardly and they will with central section 36 define a plow enclosure space in which substantial quantity of material can be retained by the plow as it is moved forwardly. As seen in Figure 6, the material in windrow 70' has been taken up in the plow retaining space 72 and carried forward to location 73 where it is deposited for further disposal etc. If a coventional plow was used to move windrow 70' there would regardless of blade angulation relative to travel direction A, result in a spillage of material at one or both ends of the plow leaving new windrows. This Figure 6 use of the plow eliminates unneeded cleanup passes with the grader when eliminating windrows. Figure 7 shows use of the plow for grading at a curb line 80. The plow 24 can be angled, e.g., so that the left end is the toe end for working the left side curb line. The panel members 42,44 will be extended and the principal cutting action will be effected by panel member 44. Panel member 42 will serve principally as a retention component. As the grader moves forwardly the plow will cut the grade at the curb line and because panel member 44 presents a sharp angle of attack to the grade surface removed material will be impelled along the panel member 44 onto the moldboard central section with little likelihood that such removed material will rollover the moldboard toe end and onto the curb frame. A conventional plow set in similar orientation presents a flatter angle of attack and less material sideways flow momentum so that possibility of roll over at the toe end is greater. In this configuration of plow 24 it also functions to retain substantial amounts of debris as at 82 so as to carry it forwardly thereby reducing windrow formation at the heel of the plow. Figures 8 and 8a illustrate another use and particular plow adaptability for grading around obstructions such as manholes 90, sewer boxes 92, etc. as are commonly located along a curb line. To effect grading in this confined space, the grader will be stopped and the plow translated leftwardly on the grader mounting frame to access the space. Panel 44 will be in first position. When panel member 44 is thereafter moved to second extreme position as shown in dashed lines, such movement will scoop-grade material rightwardly to cut the grade. The plow can then be translated rightwardly to the position shown in long and short lines to further grade cut the space and also carry cut material away from the space between the manhole and the sewer box. A conventional plow cannot be used as efficiently for this purpose as the plow of the invention. Figure 8a shows two additional ones of the many other accessing dispositions the plow can be given when grading near ,e.g., the manhole 90. The upper horizontal plow orientation allows reaching right to the curbline for scoop grading above the manhole. The lower plow orientation shows how the panel member 44 when worked back and forth between first and second positions can be used to scoop grade the area in between the manhole and the curbline. Figures 9 and 9a show use of the plow to simultaneously cut a roadway grade 100 and water run-off inclines 102,104 at the roadway margins at the same times. For this purpose, the moldboard will be inclined in a forward direction from vertical axis PF resulting in similarly shifting the pivoting axes of the panel members so that when the panel members are extended they skew below the horizontal edge of the moldboard central section and locate at an incline thereto that allows for cutting the roadway surface and run-off inclines at the same time. Three separate passes of a grader fitted with a conventional plow would be required to duplicate the single pass of plow 24. Figures 10 and 10a show the manner in which a gully 120 can be formed with plow 24 so as to cut at the same time the gully base surface 122 and upwardly inclined side wall confines 124,126. In this configuration, the plow will be tilted so that its moldboard is inclined rearwardly of vertical axis PR and the panel members moved to extended positions, the panel members serving to cut the inclined walls. Figure 11 shows a further important utility plow 24 possesses. Thus a boulder 110 can be girded between the rear face of extended panel member 42 and the front face of moldboard end section 32. By retracting the panel member, a clamping force is applied to hold the boulder and it can be carried off by the grader to a deposit location. It is also possible to use the plow in this mode to clamp an inground object such as a post and remove same by elevating or upwardly pivoting the plow. Thus, embodiments of the present invention provide an improved grading plow construction, the use of which enlarges the scope of grading operations possible with motor graders and further makes such operations more efficient and economical.

Claims: A plow (24) for a motor grader (10) or the like, comprising: an elongated moldboard (30) having as a unitary component along its length opposite moldboard end sections (32, 34) and a central section (36) between said end sections (32, 34); and a panel member (42; 44) pivoted at one of its ends to said moldboard (30) and being swingable with respect to the moldboard (30) from a first position to a second position wherein it is disposed at an angle with said moldboard (30); characterised in that said panel member (42; 44) is pivoted proximate the juncture of one moldboard end section (32; 34) and said central section (36) and rests in said first position against said one moldboard end section (32; 34) in covering contact therewith to define a substantially conventional plow configuration along said one moldboard end section (32; 34) and defines in said second position with the moldboard central section (36) an enclosure boundary defining a plow retention space (72) suitable for retaining graded material on the plow (24) as it is moved in a grading pass over a surface being graded. A plow (24) as claimed in claim 1, including a pair of said panel members (42, 44) each pivoted at one of its ends to said moldboard (30) proximate the juncture of opposite moldboard end sections (32, 34) and said central section (36) by means of respective first and second hinge means (46, 46a, 48, 48a, 50) carried on the moldboard (30) at a front face thereof; and power means (54, 56) carried on said moldboard (30) and connected with said panel members (42, 44) for pivoting said panel members (42, 44) between said first and second positions. A plow (24) as claimed in claim 2, in which the moldboard (30) has a cross-section of arcuate configuration with the moldboard (30) presenting curved front and rear faces, and the panel members (42, 44) each have an arcuate cross-section so that in said first position the panel members (42, 44) lie nested against the front face of respective moldboard end sections (32, 34) in covering closely conformable contact therewith. A plow (24) as claimed in claim 2 or 3 in which each panel member (42; 44) is of such length that when disposed in said first position an opposite end of the panel member (42; 44) extends longitudinally a distance beyond the corresponding moldboard end section (32; 34). A plow (24) as claimed in claim 4 in which the length of each said panel member (42; 44) is such that in the second position the said opposite end thereof is located longitudinally beyond the corresponding moldboard end section (32; 34). A plow (24) as claimed in claim 2 in which said power means (54, 56) is operable to move said panel members (42, 44) from said first to second positions thereof in a range of such second positions and hold said panel members (42, 44) in a selected position. A plow (24) as claimed in claim 6 in which said power means (54, 56) comprises hydraulic cylinder units (56) disposed at the rear face of the moldboard (30). A plow (24) as claimed in claim 7 in which the first and second hinge means (46, 46a, 48, 48a, 50) comprises for each a pair of hinge pieces (46, 48) fixed to said moldboard (30), there being a second pair of hinge pieces (46a, 48a) fixed to said end of a panel member (42; 44) and rotatably connected with said first hinge piece pair (46, 48), the hydraulic cylinder unit (56) associated with each panel member (42; 44) including a sliding rod (54), one of said hinge pieces (46a) of said second pair including a crank extension (49) extending to the rear face of the moldboard (30) and being connected to the sliding rod (54). A plow (24) as claimed in claim 2 in which the moldboard (30) carries fairing plates (58) each having a face surface inclining from minimum thickness thereof at the moldboard (30) front face to a maximum thickness adjacent an edge thereof which is juxtaposed with an edge of its associated panel member (42; 44) when said panel member (42; 44) is in said first position so that material moving along the moldboard (30) in the direction of said panel member (42; 44) can pass onto the panel member (42; 44) with minimized obstruction to said flow. A plow (24) as claimed in claim 2 in which the moldboard (30) has top and bottom longitudinal edges, said plow (24) further comprising a cutting edge member (64) carried on the moldboard (30) bottom edge intermediate said first and second hinge means (46, 46a, 48, 48a, 50), each panel member (42; 44) having a bottom edge and a cutting edge member (66) carried at said panel member (42; 44) bottom edge. A plow (24) as claimed in claim 10 in which each panel member (42; 44) carries a transversely directed cutting edge (68) at its other end. A plow (24) as claimed in claim 10 or 11 in which the said cutting edges are readily removable/replaceable components.

Inventors: VECCHIO CHARLES J, VECCHIO, CHARLES J.
Applicants: VECCHIO CHARLES J, VECCHIO, CHARLES J.
Application year: 1989
Main classification: E02F3
IPC codes: E02F3