US3777822A

US3777822A - Conveyorized motor grader blade with retractable end bits

Info

Publication number: US3777822A
Application number: US00240167A
Authority: US
Inventors: R Sullivan; R Stedman; B Griffith
Original assignee: Caterpillar Tractor Co
Current assignee: Caterpillar Inc
Priority date: 1972-03-31
Filing date: 1972-03-31
Publication date: 1973-12-11
Anticipated expiration: 1990-12-11

Abstract

A blade assembly for a motor grader having a power driven endless belt conveyor for forcibly moving material to one side of the blade assembly is provided with end bits for facilitating operations such as bank cutting, ditching and the like in which stress may be concentrated at one end of the blade assembly. The end bits greatly reduce the wear and risk of damage which can otherwise occur at the cutting end of the conveyor. While the movement of the conveyor tends to prevent jamming of materials between the conveyor and end bit at the cutting end of the assembly, an opposite situation prevails at the discharge end. To avoid jamming at the discharge end, the end bits are retractable whereby only the bit at the cutting end need be maintained in the operative position.

Description

United States Patent mi Stedman et al.

[45] Dec. 11, 1973 [54] CONVEYORIZ'ED MOTOR GRADER BLAD WITH RETRACTABLE END BITS [73] Assignee: Caterpillar Tractor Co., Peoria, Ill.

954,386 4/1910 Ganser 172/782 X Primary Examiner-Robert E. Pulfrey Assistant Examiner-Stephen C. Pellegrino Attorney-Donald J. McRae et al.

[57] ABSTRACT A blade assembly for a motor grader having a power driven endless belt conveyor for forcibly movin'g material to one side of the blade assembly is provided with end bits for facilitating operations such as bank cutting, ditching and the like in which stress may be concentrated at one end of the blade assembly. The end bits greatly reduce the wear and risk of damage which can otherwise occur at the cutting end of the conveyor. While the movement of the conveyor tends to prevent jamming of materials between the conveyor and end bit at the cutting end of the assembly, an opposite situation prevails at the discharge end. To avoid jamming at the discharge end, the end bits are retractable whereby only the bit at the cutting end need be maintained in the operative position.

5 Claims, 5 Drawing Figures CONVEYORIZED MOTOR GRADER BLADE WITH RETRACTABLE END BITS BACKGROUND OF THE INVENTION This invention relates to motor graders and more particularly to the cutting blade component of motor graders which intercepts earth or the like and carries such material to one side of the path of travel of the grader.

The blade of a conventional motor grader is normally angled relative to the direction of travel of vehicle in order to cause intercepted earth to travel to one side of the blade. One undesirable effect of this angling of the conventional blade is that the width of cut is thereby reduced. ln certain specialized types of motor grader operations such as bank cutting, ditching and the like wherein material` should preferably be carried upward as well as sidewardly, reliance on angling of the blade may not be fully satisfactory.

In orderto overcome these problems, side casting motor grader blades have been developed in which the conventional rigid blade is replaced with a blade assembly defned in part by an endless belt conveyor driven by a motor whereby material is forcibly carried to one side of the cut. In many instances, such a conveyorized blade need not be angled and thus a cut having a width equal to the full length of the blade may be made thereby increasing the working efficiency of the grader. In instances where the blade must be sloped such as in ditching, bank cutting and the like, the conveyor action is much more efficient with respect to carrying material towards the elevated end of the bladefA conveyorized 'side casting motor grader of this general type is disclosed in co-pending application Ser. No. 15,664 now abandoned, of Marvin E. Beyers, et al., filed Mar. 2, 1970, and entitled MOTOR GRADER WITH POWER ACTUATED SIDE CASTING MEANS. A notable problem with conveyorized motor grader blades is that an endless belt conveyor tends to be less resistant to wear and damage then the conventional rigid mold board or blade and is more expensive to replace. The resultant relatively high maintenance and repair costs have tended to discourage wide spread use of this otherwise highly advantageous construction.

In many motor grader operations, one end of the blade assembly does a large proportion of the earth cutting and the cut material then travels along the blade and is discharged around the opposite end. In these operations, the cutting end of the blade sustains the greatest stress concentrations and risk of damage. This occurs, for example, in level grading where one end of the blade cuts along a window and in ditching and bank cutting operations where the lower end of the sloped blade is relatively more exposed to wear and damage.

To reduce wear and damage it has sometimes been the practice to provide end bits which are short rigid blade like cutting members extending outward from the ends of the conveyor to relieve the end of the conveyor itself of much of the task of cutting into virgin soil. When wear or damage does occur, it is much simpler and more economical to replace such end bits than to replace the conveyor itself. However, the conventional end bit itself is subject to problems as a narrow passage is necessarily present between the end bit and the adjacent end of the moving conveyor and rocks or other debris can become jammed between the conveyor and end bit. This does not tend to occur at the cutting end since the movement of the conveyor at this end is such as to tend to draw such objects away from the passage between the conveyor and adjacent end bit. However, an opposite situation. prevails at the discharge end where the conveyor movement tends to pull small rocks and the like into the gap between the conveyor and end bit. As a consequence, damage, jamming and severe wear tend to occur at the discharge end of a conveyorized motor grader blade equipped with end bits.

` SUMMARY OF THE INVENTION This invention provides an end bit on a conveyorized motor grader blade assembly which is selectively retractable. The end bit may be positioned to form an extension of the earth intercepting surface to relieve the adjacent end of the conveyor of much of the earth cutting work and may also be shifted to minimize the risk of jamming when the adjacent conveyor end functions as the discharge end of the assembly. In one form of the invention means are provided for manually shifting the position of the end bit and in another form, powered means provide for shifting one end bit into the operative position and for simultaneously shifting another end bit at the opposite end of the conveyor to the inactive protected position.

Accordingly it is an object of this invention to increase the operating efficiency of motor graders having conveyorized blade assemblies and to reduce wear, maintenance cost, and the risk of damage in connection with such mechanisms.

The invention together with further objects and advantages thereof will best be understood by reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a perspective view of a motor grader having powered retractable end bits in accordance with the invention,

FIG. 2 is a plan section view of the conveyorized blade assembly of the motor grader of FIG. l taken along line II-II thereof,

FIG. 3 is a foreshorted elevation view of the back of the conveyorized blade assembly of FIG. 2 taken along line III-Ill, thereof,

FIG. 4 is a plan view of a second embodiment of a conveyorized motor grader blade assembly having retractable end bits in accordance with the invention, and

FIG. 5 is a front elevation view of the blade assembly of FIG. 4.

Referring now to FIG. 1 there is shown a motor grader l1 which may be of conventional construction except for the side casting blade assembly l2 to be hereinafter described. Salient features of such a motor grader may include an engine 13 and an operators station 14 supported on rear wheels 16 and a mainframe member 17 which extends forward to a bolster 18 supported on front wheels 21. A triangular drawbar 22 has a forward end coupled to bolster 18 by a ball and socket joint 23 and supports a rotatable blade circle 24 to which blade assembly 12 may be attached by angled arms 26 at each side of the blade circle. Lift mechanisms 27 and blade circle rotating means 28 are provided whereby the operator may raise, lower, slope and angle the blade circle, suitable detailed construction for such blade circle positioning means being well known in the art.

Blade assembly 12 has a frame 31 attached to the blade circle through the angled arms 26 and which normally extends in a substantially transverse direction beneath the central portion of the vehicle although it may, as described above, be selectively angled or be sloped at one side or the otherof the vehicle by appropriate operation of the conventional blade circlel positioning means. Referring now to FIGS. 1 to 3 in conjunction, a cylindrical drive drum 32 is supported at one end of frame 31 for rotation about a vertical axis through the end thereof and an idler drum 33 is similarly supported at the opposite end of the frame for rov tation about a parallel axis. The endless belt conveyor 34, preferably having grousers 36, is engaged on

drums

32 and 33 whereby rotation of the drive drum 32 causes the portion of the belt forming the forward facing earth intercepting surface 38 to travel continuously from one end of the balde assembly l2 to the opposite end thereby forcibly carrying earth to one side of the motor grader. In order to drive the belt 34, a reversible fluid operated rotary motor 39 is mounted on frame 31 and coupled to a pulley 41 of the drive drum 32 by means such as a drive belt 42. Motor 39 is reversible so that material can be selectively discharged at either 'side of the motor grader.

To provide additional support for the forward or earth intercepting surface 38 of belt 34 a series of vertical rollers 43 may extend between the upper and lower portions of frame 3l behind surface 38. To reduce wear of the lower edge of belt 34, a small fixed cutting edge 44 is secured along the forward edge of the under side of frame 31 and extends a short distance forward and downward from the belt.

As described to this point, the blade assembly 12 is effective to perform the usual function of a motor grader blade in that as the vehicle is driven forward with the blade assembly 12 in a working position, surface 38 of belt 34 intercepts earth and forcibly carries such earth to one side of the path of travel. However, as previously pointed out, rapid wear of the conveyor belt would occur in the absence of further structure. Such wear and possible damage tends to be concentrated at the end of the belt which is cutting into a maximum depth of undisturbed soil which end is normally the end at which belt 34 moves forwardly around the adjacent drum. Thus in the grading operation depicted in FIG. 1, the end of the blade assembly 12 which is on the operators right is cutting into a bank of earth 46 and belt 34 is traveled in the direction indicated by arrow 47. In this mode of operation, the right end is most subject to wear and possible damage. The opposite end of the blade assembly 12, that is the left end from the operators point of view, functions largely to discharge loose material which has traveled across the front of the assembly.

To reduce wear and the risk of damage at the cutting end of the blade assembly 12,

retractable end bits

48R and 48L are provided at the right and left ends respectively of the blade assembly 12. Referring again to FIGS. l, 2 and 3 in combination, end bit 48R includes an upright flat rectangular blade 49R extending adjacent belt 34. Blade 49R is pivotable about the rotary axis of idler drum 33 from a position at which the blade outwardly utwardly from vthe end of assembly l2 to effectively form an extension'of the earth intercepting surface 38 thereof to a retracted position at which the blade is swung around behind the adjacent end of the conveyor belt 34 as will hereinafter be described in more detail.

To support blade 49R in this manner, a rotatable vertical shaft 51R is disposed along the axis of drum 33 and extends a small distance above and below the drum and frame 31. Upper and

lower pivot arms

52R and 53R extend radially from the ends of shaft SIR above and below the frame. Upper and lower

triangular brackets

54R and 56R respectively attach blade 49R to

arms

52R and 53R respectively. lf desired, blade 49R,

pivot arms

52R and 53R, and

brackets

54R and 56R may readily be formed as a single integral element.

The left end bit 48L is of essentially similar construction and thus includes an upright blade 49L attached to a vertical shaft SIL which extends along the axis of drive drum 32, upper and

lower pivot arms

52L and 53L, respectively, and upper and

lower brackets

54L and 56L, respectively, which attach the blade member to the upper and lower pivot arms.

When either of the end bits 48 is in the active position at which the associated blade 49 forms an extension of the earth intercepting surface 38, the direction of movement of the conveyor belt 34 is such as to prevent jamming of rocks or the like between the conveyor and that particular blade. However, this is not true of the blade 49 at the opposite or discharge end of the assembly 12 wherein the conveyor movement tends to pull such objects into the gap between the belt and blade 49. Accordingly, the present invention provides for retraction of the blade member 49 at the discharging end by swinging such blade partially around the adjacent end of conveyor belt 34. At the retracted position the blade 49 is out of the principal path of travel of materials discharging around the conveyor end and is obliquely inclined relative to such path, the left end bit 48L being in this retracted position in FIGS. l, 2 and 3.

As the operator may wish to use flrst one end of the blade assembly l2 as the cutting end and then use the other end for such purpose without dismounting from his station 14 to make adjustments, it is advantageous to provide powered means for Shifting the end bits so that either can be selectively moved to the active position while the other is simultaneously retracted. One means for this purpose, depicted in FIGS. l to 3, consists of a triangular plate 57 pivotable on a vertical axle 58 mounted at the center of the top surface of frame 31. A hydraulic jack 59 has one end pivotably coupled to the left angled member 26L and the other end pivotably coupled to one point of triangular plate 58 whereby extension of the jack turns plate 58 in one direction and contraction of the jack turns the plate in the opposite direction. A right link 61R is pivotably connected between end bit pivot arm 52R and another point of triangle 58 while a left link 61L is pivotably connected to the third point of plate 58 and upper pivot arm 52L of the left end bit. Plate S8 and links 61 are proportioned, relative to the stroke of jack 59, whereby retraction of the jack forces the right end bit 48R into the active position while pivoting the left end bit 48L into the inactive position while extension of the jack shifts end bit 48L into the active position while retractingend bit 48R.

It will be appreciated that other structure may be used to provide for alternate movement of an end bit between an active position and an inactive position. For example,-the end bits need not necessarily pivot about vertical axes as in the above described embodiment and a less complex and costly system is possible where shifting of the end bit and securing the end bits in either position are performed manually. FIGS. 4 and S in conjunction illustrate a second embodiment in the invention wherein both of these modifications are present.

In the embodiments of FIGS. 4 and 5, the blade assembly 12' may be essentially similar to that of the previously described embodiment insofar as the frame 31 drums 32' and 33', motor 39', belt 34' and cutting edge 44 are concerned and accordingly such elements will not be redescribed in detail. To support the end bits 48R' and `48L' in this embodiment a fixed shaft 62 extends along the top surface of frame 3l in parallel relationship therewith and in parallel relationship with the forward surface 38' of the conveyor, the shaft being secured to frame 31' by suitable brackets 63.

The

end portions

64R and 64L of shaft 62 which extend beyond the ends of belt 34 at the right and left ends respectively are of reduced diameter. Each endbit 48R and 481.' consists of a rectangular blade 66 hav ing a sleeve 67 formed along the upper edge thereof for disposition on the associated

end portion

64R or 64L of shaft 62. A washer 68 is disposed on each shaft end 64 between sleeve 67 and the larger diameter portion of the shaft and a threaded nut 69 or other suitable fastening means retains the sleeve on the shaft end portion. Thus each blade 66 may be swung upward to a substantially horizontal inactive position as depicted at 4BR in FIG. 4 or may be swung downward to an active position as depicted at 48L to form an extension of the earth intercepting surface 38' of the conveyor 34.y

To provide for securing each blade 66 in either of the above described positions, an angled bracket 71 is secured to the back surface of the blade at the comer which is adjacent conveyor belt 34' and remote from sleeve 66, the bracket having a bore 72 therethrough.

Each bracket 63 has an upwardly and outwardly extending arm 73 with a bore 74 positioned to be in alignment with bore 72 when the plate 66 is swung upward to the inactive position. Thus a bolt 76 or other suitable fastener may be inserted through

bores

72 and 74 to secure the end bit in the inactive position. To secure the end bit in the lowered or active position, angled brackets 77 are secured to lower portion of frame 31 at each end thereof and have bores 74 positioned to receive the bolts 76 when the associated end bit is in the lowered or active position. As in the previously described embodiment, the particular end bit 48 adjacent the end of the assembly 12' at which conveyor belt 34 is traveling forwardly is normally fixed in the active position while the end bit at the opposite end of the assembly wherein the material is being discharged is fixed at the inactive or raised position.

While the invention has been described with respect to certain exemplary embodiments, it will be apparent that many other modifications are possible and it is not intended to limit the invention except as defined in the following claims.

What is claimed is:

l. A blade assembly for a motor grader comprising:

an endless belt conveyor,

a means having meahs for attachment to said motor grader and having means for supporting said belt conveyor in a substantially transverse relationship thereto to provide an earth intercepting surface as said motor grader travels forward and having reversible drive means for driving said conveyor belt to carry intercepted earth from a selected end of -said conveyor belt to the opposite end thereof,

a first end bit blade disposed adjacent said one end of said conveyor belt,

means for attaching said first end bit blade to said frame and having means providing for shifting of said blade between an active position at which said blade forms an extension of said earth intercepting surface at said one end of said conveyor belt and an inactive positionl at which said blade is retracted away from said active position, i

a second end bit blade disposed at said opposite end of said conveyor belt and means for attaching said second end bit blade to said frame and having means providing for shifting of said second end bit blade between an active position at which said second blade forms an extension of said earth intercepting surface at said opposite end of said conveyor belt and an inactive position at which said second blade is retracted away from said inactive position thereof.

2. A blade assembly for a motor grader comprising:

an endless belt conveyor,

a frame having means for attachment to said motor grader and having means for supporting said belt conveyor in a substantially transverse relationship thereto to provide an earth intercepting surface as said motor grader travels forward and having means for driving said conveyor belt to carry intercepted earth from one end of said conveyor belt to the opposite end thereof,

a first end bit blade disposed adjacent said one end of said conveyor belt,

means for attaching said first end bit blade to said frame and having means providing for shifting of said blade between an active position at which said blade forms an extension of said earth intercepting surface at said one end of said conveyor belt and an inactive position at which said blade is retracted away from said active position,

a second end bit blade disposed at said opposite end of said conveyor belt and means for attaching said second end bit blade to said frame and having means providing for shifting of said second end bit blade between an active position at which said second blade forms an extension of said earth intercepting surface at said opposite end of said conveyor belt and an inactive position at which said second blade is retracted away from said inactive position thereof, and

linkage means connected with each of said end bit blades for shifting one of said blades to said inactive position thereof while shifting the other of said blades to said active position.

3. A blade assembly as defined in claim 2 wherein said means for attaching said first end bit blade to said frame comprises a first pivot arm rigidly connected to said first blade and being pivotally coupled to said frame for pivoting movement about a substantially vertical axis through said one end of said conveyor belt and wherein said means for attaching said second end bit blade to said frame comprises a second pivot arm rigidly attached to said second blade and being pivotally coupled to `said frame for pivoting movement about a substantially vertical axis through said opposite end of said conveyor belt, said linkage means comprising a pivotable element mounted on said frame between said ends thereof, first and second links each connected between a separate one of said pivot arms and said pivotable element, and powered means for selectively pivoting said pivotable element.

4. A blade assembly for a motor grader comprising:

an endless belt conveyor,

a frame having means for attachment to said motor grader and having means for supporting said belt conveyor in a substantially transverse relationship thereto to provide an earth intercepting surface as said motor grader travels forward and having means for driving said conveyor belt to carry intercepted earth from one end of said conveyor belt to the oppositeend thereof,

a first end bit blade disposed adjacent said one end of said conveyor belt,

means for attaching said first end bit blade to said frame and having means providing for shifting of said blade between an active position at whichsaid blade forms an extension of said earth intercepting surface at said one end of said conveyor belt and an inactive position at which said blade is retracted away from said active position, wherein said means for attaching said first end bit blade to said frame comprises a shaft extending from said frame at said one end of said conveyor belt, means pivotably coupling said first end bit blade to said shaft, and manually disengageable means for fixing said first end bit blade against motion relative to said shaft at said active position thereof and at said inactive position thereof.

5. A blade assembly as'defined in claim 4 wherein

Claims

1. A blade assembly for a motor grader comprising: an endless belt conveyor, a means having meahs for attachment to said motor grader and having means for supporting said belt conveyor in a substantially transverse relationship thereto to provide an earth intercepting surface as said motor grader travels forward and having reversible drive means for driving said conveyor belt to carry intercepted earth from a selected end of said conveyor belt to the opposite end thereof, a first end bit blade disposed adjacent said one end of said conveyor belt, means for attaching said first end bit blade to said frame and having means providing for shifting of said blade between an active position at which said blade forms an extension of said earth intercepting surface at said one end of said conveyor belt and an inactive position at which said blade is retracted away from said active position, a second end bit blade disposed at said opposite end of said conveyor belt and means for attaching said second end bit blade to said frame and having means providing for shifting of said second end bit blade between an active position at which said second blade forms an extension of said earth intercepting surface at said opposite end of said conveyor belt and an inactive position at which said second blade is retracted away from said inactive position thereof.

2. A blade assembly for a motor grader comprising: an endless belt conveyor, a frame having means for attachment to said motor grader and having means for supporting said belt conveyor in a substantiAlly transverse relationship thereto to provide an earth intercepting surface as said motor grader travels forward and having means for driving said conveyor belt to carry intercepted earth from one end of said conveyor belt to the opposite end thereof, a first end bit blade disposed adjacent said one end of said conveyor belt, means for attaching said first end bit blade to said frame and having means providing for shifting of said blade between an active position at which said blade forms an extension of said earth intercepting surface at said one end of said conveyor belt and an inactive position at which said blade is retracted away from said active position, a second end bit blade disposed at said opposite end of said conveyor belt and means for attaching said second end bit blade to said frame and having means providing for shifting of said second end bit blade between an active position at which said second blade forms an extension of said earth intercepting surface at said opposite end of said conveyor belt and an inactive position at which said second blade is retracted away from said inactive position thereof, and linkage means connected with each of said end bit blades for shifting one of said blades to said inactive position thereof while shifting the other of said blades to said active position.

3. A blade assembly as defined in claim 2 wherein said means for attaching said first end bit blade to said frame comprises a first pivot arm rigidly connected to said first blade and being pivotally coupled to said frame for pivoting movement about a substantially vertical axis through said one end of said conveyor belt and wherein said means for attaching said second end bit blade to said frame comprises a second pivot arm rigidly attached to said second blade and being pivotally coupled to said frame for pivoting movement about a substantially vertical axis through said opposite end of said conveyor belt, said linkage means comprising a pivotable element mounted on said frame between said ends thereof, first and second links each connected between a separate one of said pivot arms and said pivotable element, and powered means for selectively pivoting said pivotable element.

4. A blade assembly for a motor grader comprising: an endless belt conveyor, a frame having means for attachment to said motor grader and having means for supporting said belt conveyor in a substantially transverse relationship thereto to provide an earth intercepting surface as said motor grader travels forward and having means for driving said conveyor belt to carry intercepted earth from one end of said conveyor belt to the opposite end thereof, a first end bit blade disposed adjacent said one end of said conveyor belt, means for attaching said first end bit blade to said frame and having means providing for shifting of said blade between an active position at which said blade forms an extension of said earth intercepting surface at said one end of said conveyor belt and an inactive position at which said blade is retracted away from said active position, wherein said means for attaching said first end bit blade to said frame comprises a shaft extending from said frame at said one end of said conveyor belt, means pivotably coupling said first end bit blade to said shaft, and manually disengageable means for fixing said first end bit blade against motion relative to said shaft at said active position thereof and at said inactive position thereof.

5. A blade assembly as defined in claim 4 wherein said shaft extends from said frame at said one end of said conveyor belt above said upright earth intercepting surface and in parallel relationship to said surface.