CA1279989C

CA1279989C - Motor grader with high-lift shift cylinder and hydraulic lock means

Info

Publication number: CA1279989C
Application number: CA000527260A
Authority: CA
Inventors: Murray A. Ross; Gordon L. Adams; Michael A. Sully
Original assignee: Champion Road Machinery Ltd
Current assignee: Volvo Motor Graders Ltd
Priority date: 1987-01-13
Filing date: 1987-01-13
Publication date: 1991-02-12
Anticipated expiration: 2008-02-12
Also published as: AU1482088A; AU608827B2; EP0339051A1; ZA88193B; WO1988005482A1

Abstract

ABSTRACT OF THE DISCLOSURE

A blade lift and support system for a road grader is taught which is of simplified construction and improved geometry. According to one embodiment, the adjustment of the beam and associated grader blade is fully hydraulically controlled including locking of the beam in a desired position and maintaining the beam position by an hydraulic fluid lock.
This preferred arrangement permits full power adjustment of the high-lift while the blade is in a lifted condition. The particular beam shape improves the position of the cylinders to effect positioning the blade for working.

Description

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The present invention relates to high-lift arrangements for a blade of a motor grader. In particular, the invention relates to an improved method of supporting the blade beneath the frame of a grader.
In the past a number of arrangernents have been proposed for supporting the blade of a motor grader and in general these can be broken into two groups. The first group uses a beam extending either side of the frame of the motor grader and pivotable about the frame, and the second group uses separate arms~ one to either side of the frame, and in many cases these arms are movable to various positions. There has also been a number of arrangements where either the beam or the arms are fixed in position on the grader frame. The fixed position arrangements are generally limited with respect to the extent and position, either side of the grader, that the blade can be positioned. In general, the most demanding specification requires that the grader blade be capable of moving to either side of the mainframe of the grader from a perpendicular position at one side~to a perpendicular position at the other. The fixed arm or fixed beam arrangement have limited adjustability, however in many applicatLons the extreme positions of the blade~will~not be used. The blade support ' `: :

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1 arrangement should be adjustable to effect 2 to 1 and 1 to 1 banking either side of the grader as well as a di-tching orientation either side of the grader.
In addition to the very demanding specifications set forth above which have generally been met with either the pivoted beam or the movable arms, the support arrangement for the motor grader blade should be convenient to use and adjust between the various positions. The system should be such that there is not any substantial fouling problems with respect to the movement of the cylinders to achieve the variaus positions, as fouling problems can lead to extensive damage af the hydraulic components and other structural components.
Furthermore, the support arrangement for the blade of the motor grader must take into account the visibility of the operator from the cab and certain specific points of the blade which are considered somewhat critical. For bank grading, it is generally noted that the heel of~the blade should be positioned outside of the wheels so that the wheels do not contact the graded surface and, ther~efore, the heel of the blade should be visible for this particular operation. Furthe~rmore, the toe of the blade should be visible as this is the other ~xtreme position that IS being graded.

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1 The ideal blade positions include the 90 high-lift to either side of the grader, a position of the blade which is approximately 63 to effect a 2 to 1 banking operation, and a further banking position of the blade at about 45. The 45 position and the 63 position are generally considered the most frequent positions of the grader blade and the positions which a system must satisfy. Therefore, the flexibility of the system and the ease of adjusting the same should be evaluated with respect to these normal positions, although some merit must be accorded the 90 position as well as the horizontal beam position.
Our earlier patent, United States Patent 4,340,119 uses a beam centrally pivoted atop the grader frame with a locking arrangement generally provided beneath the frame. This arrangement generally satlsfies the standards~set ~orth above, however the loc~ing arrangement beneath the ~rame, which is a mechanlcal arrangement, reduces the clearance beneath the frame and requires a fair degree of accuracy with respect to~the locking posltion of the beam when the beam position is~
adjusted. The advantages of this~mechanical lo~ck are the steel to stee~l locking contact wh~ich is the generally accepted standard in the~indus~try.

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The structure previously referred to above, having movable arms either side of the grader frame, again uses a pin-type lock arrangement for fixing the arms at various positions relative to the frame and often these pins are either mechanically movable to allow adjustment of the arms or beam or are hydraulically actuated to effect adjustment of the components. However, the fixing of these components in a predetermined position on the frame is achieved by a mechanical type lock. The problem of accurate positioning for locking is compounded in the movable arm system in that two arms must be locked rather than a single beam and freezing of locks occurs rendering them difficult to release.

SUMMARY ûF THE INVENTION
The present invention provides a structure for supporting the bla~de of a~motor grader b~enea~th the frame of the ::
grader. This;arrangement lS of reduced complexlty an~ proviaes advantages wlth respect~to cost of manufacture as well;as service in the field. The~arrangement maintains the area beneath~the~fram~e of th~e grader relatively clear and~uses a ~
link-type member disposed bètween the side~of the grader ~rame and~a position on~the beam spaced from the central pivot ; ;locatlDn~of~the plv~oted~beam ~to effect locklng. In a preferre~

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1 embodiment of the invention, the link is an hydraulic cylinder thus allowing an infinite number of positions of the beam relative to the grader frame. The hydraulic cylinder also acts as an hydraulic lock, thus overcoming the precision problems associated with a mechanical lock.

~RIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in the drawings wherein;
Figure 1 is a partial perspective view of a high-lift arrangement for the blade of a motor grader;
Figure la is a perspective view of manual lock link;
Figures 2 and 3 are rear elevational views of the high-lift;
~Figure 4 lS a slmilar rear elevational v1ew with the high-lift rotated to one side of the motor grader;
Fi~gure 5 lS a -ront~elevational of a~modified structure; ~
Figure 6 is a rear view of the high-lift;~ and Figure 7 is a rear view of a modified version of the beam ànd the connect~ion polnts of components to the frame.
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The mainframe 2 of the motor grader supports adjacent the cab a generally horizontally extending support beam 4, which universally supports at 19 hydraulic lift cylinders 6 at either end of the support beam. The cylinders 6 are connected to a ring gear 8 via beam 7 which provides the main support of the road grader blade 9. Beam 7 is pulled by the grader by means of drawbar 3. The arrangement for supporting of the blade 9 beneath the ring gear and the ring gear are known from our earlier patent U.S. 4,340,119 and the prior art in general. The invention of the present application is generally directed to the high-lift arrangement 5 for the blade 9. The support beam 4 is pivotally supported on the shaft 10 which extends in the fore and aft direction of the main~rame of the road grader. The shaft 10 is secured to the mainframe 4 by two pivoted saddle arrangements 26 to either side of the beam 4.
The beam itself intermediate the saddles 26 includes a downwardly extending portlon which includes bearings for cooperation with the shaft 10 to thereby pivotally secure the beam 4 atop the mainframe 2 of the motor grader. The beam 4 rotates ~rom the generally horizontal position of Fiyure 1 through an angle of about~ 70, 35 either side~ of the horizontal positlon. The llft cylinders 6 are universally 1 ~79~8~3 1 supported adjacent the extrerr~ities of the beam 4 at a position generally below shaft 10 (when the beam is horizontal). In this way, the points of securement are such that with a counterclockwise rotation of the beam 4 shown in Figure 2, the point of securement 19 of the lefthand cylinder is below the horizontal line passing through shaft 10 and as such, will move through a further distance toward the frame 4 of the grader for a predetermined amount of rotation. This is desired as problems occur in achieving the 90 location and these problems are reduced by positioning the cylinders such that the far cylinder in a 90 blade position is moved as far as possible beneath the frame of the grader, while the other cylinder is rotated upwardly through the horizontal passing through shaft 10 and as such~ its position is still quite spaced from the mainframe. Therefore, by positioning the support positions of hydraulic cyIinders 6 below the horizontal line passing through shaft 10, advantages are achieved with respect to both cylinder~s when considered with respect to the requirement to position the blade at 90 to either side of the motor grader. The preferred separation of the cylinders is fifty inchès.
Integral with beam 4 and to one side of the mainframe 4-is a downwardly and rearwardly extending arm 14 having an end : :

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~ ~ ~g 9~3 1 15 which is rearwardly offset relative to the center line of the beam 4 about eight inches. An hydraulic shift cylinder 16 is secured to the end 15 and shifts the ring gear 8 in a generally traverse movement relative to the mainframe 4. In this way, the position of the blade, either beneath the grader or to the side thereof, is accomplished. As can be seen from the figures, arm 14 is spaced from the mainframe of the grader when the beam is in the generally neutral position and is positioned to allow, without interference, the desired rotation of the beam about shaft 10. To the other side of the frame 4 as shown in Figure 1 and Figure la, is a lock link 20 which is pivotally secured to the beam at position 22. The other end portion of the lock link is pinned or secured to the side of the frame 4 of the grader by pin or securing means 24. The link 20 includes a number of circular holes 23 in the length thereaf which are positioned to achieve the desired fixed positions of the beam relatlve to the grader. In this case, the link provides a manual type lock arrangement where it would be necessary:for the operator to remove the pin 24 and cause rotation of the beam 4 to the~desired position and effect locking by replacing the pin 2~i in an appropriate aligned aperture in flange 25. This lock link arrangement pinned to the slde of the mainframe of the grader maintains the space :: :

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1 beneath the road grader substantially clear and allows the ringgear 8 to essentially come immediately below the grader frame (with five inches clearance) to effect a fairly high ground clearance of the blade directly beneath the frame as schematically shown in Figure 4. Furthermore, this simple lock arrangement greatly reduces the cost and it can be recognized that advantages are achieved in that if wear does occur, either pin 24 or the various connections of the link 20 to the beam 4 or the beam to the frame can be accomplished quite easily. The lo bearings type connection associated with each of these components are common an~d are~readily available and easily replaced by the people in the field. Such is not the case in prior art structures where, in some cases, a very large bearing is placed completely about the frame of~the grader wlth~a beam rotating about the~center axls of the frame. The point of securement of the`link 20 to the beam 4 is spaced from the shaft lû to re~uce the stress concentration on the beam 4 at securement point 22.
However, the beam can withstand substantial stress and the position~of~lock arrangement, generally close to the ma~inframe of the grader, improves~vlsiblllty o;f the blabe beneath the grader frame. For~example,~the link 20 could be positloned~
further along the~beam 4, thus increasing the distance between securement~ point 22 and shaft 10, however this then obs~tructs a , ~

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~'~'7g ~ 3 1 further area beneath the beam 4 whereby visibility of the operator is marginally reduced and stress is significantly reduced. Therefore, the position as shown, which is generally within about 12 inches of the shaft 10, does concentrate or provide a high stress area at point of securement 22, however, for light application, this can be accommodated in the design of the securement of the link 20 to the beam.
In the embodiment of the invention as shown in Figures 2 through 4, the link 20 has been replaced by a dauble acting hydraulic cylinder 34 generally universally supported to the side of the frame 2 of the grader via flange 25. The cylinder 34 has been secured intermediate the length of the barrel portion 36 to allow for a somewhat greater stroke of the cylinder. The piston 38 of the cylinder 34 is secured at point 22 to the beam whereby the position of the beam relative to the mainframe 4 is~accomplished by adjusting the cylinder. This results in an arrangement which effectively provides an infinite number of positions of the beam between its extreme points of rotation, with~the lock~ing of the beam being accomplished by the hydraulic cylinder 34. It is also possible to introduce an hydraulic pressure relief switch whereby if forces are encountered exceedi:ng the~maximum deslgn, the relief valve would~be actuated momentarily releasing lock cylinder 34 : ~ . :

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~'799~3 1 to avoid damage. The hydraulic cylinder 34 thus allows powered positioning of the beam and does not require the resting of the blade on the ground to effect adjustment. In most prior art arrangements, it has been essential to place the blade on the ground and allow the remaining cylinders to move in response to repositioning of the beam, with the beam subsequently being locked, whereafter the other hydraulic components can be adjusted as necessary. Such is not the case with the hydraulic control arrangement of the beam of the present invention, as hydraulic cylinder 34 is under power and allows positioning of the blade as desired.
A modified arrangement is shown in Figure 5 wherein the double acting hydraulic cylinder 34 has been relocated and repositioned to improve the load carrying capabilities of the components. The double acting cylinder 34a has the piston 38a pivotally secured to the frame 2 at 21a a~djacent the lower~edge and to one side of the frame by means of brackets 25a. The barrel 36a ls~pivot~ally~ secu~red to beam 4~at~35a spaced outwardly of shaft 10 and to the same side of the frame as position 21a. The~;point of securement 35a is~selected to reduce high stress concentrations~and avoid cylinder fouling.
The triangle formed by the position of securement 35a, point 21a~and shaft 10~results in lower stress~than the arrangements ~:
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1 of Figure 1 through 4. This arrangement requires a greater stroke for cylinder 34a and, therefore, the orientation of the cylinder has been reversed to extend above beam 4. The lift cylinder 6 is secured to the side of the beam 4, opposite cylinder 34a, to minimize the possibility of fouling. Cylinder 34a will always remain in the same plane, whereas cylinder 6 does not.
The arrangement of Figure 5 advantageously separates shaft 10, securement point 35a and position 21a, to reduce stress. By having shaft 10 above the frame 4, the distance to point 21a is increased. Thusj the structural characteristics are improved, although some loss of visibility is suffered due to cylinder 34a extending above beam 4. The higher load carrying capability of the arrangement of Figures 5 through 7 are preferred.
Again, beam 4 may be fabricated of plate~steel in a box type cross-section, in wh1ch case, ports top and bottom can be provided and cyl~inder 34a can extend through the~beam 4 The simplified shape of the beam 4 makes fabrication from plate steel a competitive alternatlve to~a cast beam~.
With the arrangement as shown in the drawings, the grader blade may be positioned to either side of the mainframe 4 and the blade posi~io~ned at 90 to either side of the ~ 2 -:: : :

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1 mainframe. Therefore, the support achieves the full flexibility of prior art systems while simplifying the support structure resulting in lower manufacturing costs, improved operating characteristics as well as simplified service in the field. Furthermore, in the preferred embodiment where an hydraulic cylinder is used to lock the beam and cause rotation of the beam as desired, full flexibility in the positioning of the beam under the weight of the blade is accomplished.
The blade position in the horizontal beam orientation and rotated for 90 high-lift as well as the blade positions are shown in Figure 6. Figure 7 is a rear view of a beam of additional depth and showing details of the mounting of the hydraulic lock cylinder.
The particular geometry lS shown in Figure 6 and includes the points of securement of the lift cylinder 6 to the beam 4, the pivot of the beam, the beam width, the securement of the drag link 16 to the downwardly depending arm 14 and the points of securement of the lift cylinders~t~o the beam 7 and the securement of the drag link 16 to the beam 7. This geometry~has proven most satisfactory. The beam 4 spaces the cylinders 6 apart approximately 50 inches at the beam and the lift cylinders are secured to the beam 7 at a spacing of about 48 Inches. This causes the cylinders to adopt a neutral :

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1 position as shown in Figure 6 where the cylinders are initially angled slightly outwardly to generally follow the progressively opening window of the cab of the grader. The 50 inch spacing of the cylinders either side of the beam is substantially reduced relative to the industry, where a minimum spacing of 52 inches and a more normal spacing of 54 inches have been used.
The narrower spacing of the beam in combination with the improved clearance beneath the frame and particular location of the points of securement of the lift cylinders below the axis 10 of the beam (about two inches), or at least in line therewith, allows the desired positioning of the blade 90 either side of the grader as well as positioning of the blade for banking at a 2 to 1 or 1 to 1 ratio and a ditching position. The distance between securement of each cylinder 6 to the beam and the end position of the piston portion of the cylinder at maximum stroke is about 70 inches. The height of the cylinder above the beam is such to allow for full retraction of the piston portion of the lift cy~linder. The minimum retracted positlon of the drag cylinder 16 is 38 inches and this cylinder has a stroke of about 27 inchbs. The point of securement of the drag link~16 to the beam 7 is offset from~ ~ ;
the center l~ine of the beam and the center line of the grader :
about 21~ inches. The spacing of the lift cylinders on the beam , :: ~

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~ 9 ~53 l 7 again are symetrical about the center line and are separated 48 inches. The upper securement of the drag link 16 to the depending arm 14 is about 19-1/2 inches below the horizontal passing through the axis lO and is of~set from the center line of the beam about 16-l/4 inches. These dimensions are all center line to center line.
This arrangement allows a full 90 high-lift position with the blade approximately 21 inches above the ground and the beam 7 approximately 31 inches above the ground, and the blade is positioned outwardly of the tires lOl of the grader such that the far edge of the blade is about 33 inches from the outer edge of the tire. In order to achieve a 2 to l bank sloping position, the cylinders are adjusted with the beam in its fully rotated configuration and this results in the blade being lowered towards the ground and the lower outer tip of the blade will~be approximately 6 inches above the ground and located exteri~or to the tire approximately 20 inches. To effect a l to l banking sloping operation, the blade moves inwardly whereby the lower tlp of the blade is approximately lO
inches spaced outwardly of the tlre and again is approximately 6 inches clear of the ground. Therefore, in both the 90 high-lift positions, the 2 to l bank~ing posltion and the 1 to l ~
banking~position,~ the~lower edge of the~blade can be positioned ;;

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,7998'~'3 1 above the ground for working a bank where any excess material can accumulate to the exterior of the tire in the gap between the lower edge of the blade and the tire. Thus, the tire does not ride on the ridge of material that may accumulate and as such, a fairly constant slope can be achieved. With the high-lift in a fully retracted position (solid lines in Figure 6) with the beam horizontally disposed, the bottom of the blade allows a ground clearance of over 17 lnches and is movable to a maximum lower position o~ approximately 20 inches below grade.
One of the problems associated with a pivotted beam high-lift is that~the 90 high-lift position should be possible elthe~r slde~of the road grader, and in some prior art arrangements the drag~link 16 has been reversible~in that it is capable~of~ being~sec~ured~either side of the cente~r of the beam 7 and the~f~rame 2. ;Such~ s~n~ot necessary ln~the~present structure~where,;~due~to;th~e~part~lcular geometry,~rotatLon~of the beam~to~the opposite~side a~nd full retraction of the~drag link~l6~ac~c~ommo~dates~the~90~conflgurat~i~on to the~ oppos~ite;~
sid~e~of~the~gr~ad~er.~Thus,~;to~a~ch~ieve the 90 orientation~to one~side,~the~;~drsg;~ nk~ls~es~sent~ially~full~y~extended~and to~
achieve~the~90 ~to~t~he~ op~posite side~,~the d;rag~link~16 i~s essent~islly~fùlly~retrac~ted~

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, 9~ 3 1 With the hydraulically locked beam shown in Figure 5, the operator has full flexibility in positioning of the beam 4 for various operations. Specialized applications in the field can take full advantage of this flexibility, however the normal positions of bank sloping at a 2 to 1 slope or 1 to 1 slope or the 9û high-lift either side are possible by fully rotating the beam to the appropriate end position and then adjusting the cylinders. By reducing the spacing between cylinders and the particular securement of the cylinders in combination with the securement of the drag link, problems, associated with cylinders reversing over center which create a lock situation where the cylinders are fighting each other, are greatly reduced in that the movement of one cylinder generally causes the other cylinders to move in the desired manner. This improved cooperation between the cyllnders is achleved due to the particular geometry of the system.
In the hydraulically locked~ beam of Figures 5 and 7, several advantages have been achieved~by posltionlng the securement 39 and ~lock cylinder 36a fairly close to the lift cylinder 6 and generally tow~ards the end o~ the beam~4. The~
lift cylinder 6 is located to one slde of the beam and does~not~
remain in a vertical plane and r~otates ln certain blade :
positions~over t~he beam.~ By posltioning the cylinder 36a :
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1 generally close to the point of securement of the lift cylinder 6, the lift cylinder is displaced forwardly o~ rearwardly of the hydraulic lock cylinder 36a and this spacing is sufficient to ensure that these cylinders do not foul. As cylinder 6 does rotate through a certain angle, the distance moved does increase as you extend outwardly of the point of securement and, therefore, positioning of the cylinder 36a at a more inwardly posltion could result in a fouling situation. The cylinder 36a preferably has a stroke about 18 inches and is lo spaced outwardly of the axis 10 approximately 20.75 inches. As discussed earlierj advantages are achieved by pasitioning the lock cyllnder 36a towards the end of the beam in that stresses are reduced;and the cylinder takes a more effective angle with respect to the frame of the grader. As can be appreciated, forces carried by ~the cylinde~r result in both horizontal and vertical loads on the~frame as~opposed to the mare limited vertical~loads which result when the cylinder is positioned as shown in Figures ~and~3.
~ When cons~ldering~the geometry referred to above,~ t should be r~emembered~that~the~downwa~rdly extending arm 14~is~
rearwardly offset approximately~8~inches relative to the~center line~of the~beam;to redu~ce the chances of fouling an~ provlde ,-- :
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1 In the fully retracted position of the high-lift with the beam horizontal, there remains approximately 5 inches of clearance beneath the frame of the grader. This is a result of the stroke of the lift cylinder 6 and the relative securement to the pivotted beam 4 and the fixed beam 7. This clearance is substantially greater when compared to the structure disclosed in our earlier patent.
The composite design of the beam, which allows fabrication from plate steel and allows the hydraulic lock cylinder 36a to extend through ports 45 and 47 in the beam, also provides flexibility with respect to selecting an appropriate shape for the design forces. For example, the depth of the beam and the fore and aft directlon of the grader can be increased, and if additional width of the beam from top to bottom is necessary, then the pivot position of the beam above the frame of the grader can be increased qnd the width ~f the beam then increased. Thi~s allows a great deal of latitude with respect to the shaping of the beam~for~the loads expected~
to be encounte;red. The composlte design also~allows for a ~0 reinforcing of -the beam in the area of securement~of the lock cylinder 36a merely by addln~g~additional plates~lnteriorly or exteriorly. These~addlti;onal plates are necessary due to the weakening of the~beam due to the porting as well as the forces - , ~
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~;~t~.99~9 1 transferred to the beam by the lock cylinder ~6a. The cylinder 3~a is preferably secured to the beam such that the pivot position of the cylinder is above the beam as shown in Figure 7. Mounting blocks 49 welded to the top of the beam and a bearing arrangement 51 securing the lock cyllnder is bolted to the mounting blocks 4g. This again increases the lever arm and as such, will reduce the stress level on the axis 10 as well as securement of the cylinder to the frame and the stress at the point of securement of the cylinder to the beam. The composite beam construction simplifies securernent of the downwardly extending arm 14 and selective reinforcing of the beam to carry the required force. The beam 4 of Figure 7 is mounted slightly higher above Prame 2~to accommodate the shallower radius 57 which can be a high st~ress area.
~ A~fabricated beam 4 is preferred, however a cast beam could also~benePIt;from ~the improved~geometry~and cooperatlon of component~s. ;~
Although~varlou~s p~rePe~rred embodlm~ents~ of the present invention have~bee~n~descrlbed~herein~in detail, it will be appreciated~by those ski~lled~ln the art,~ that variations may~be made thereto without departing~f~rom the spirit of the invention or the sc~ope;oP~the~appende;d cl~a~ims.~

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Claims

1. In a motor grader having a support frame, a drawbar universally secured thereto adjacent the forward end of the drawbar, and a scraper blade rotatably supported at the opposite end of said drawbar, a beam member centrally mounted on top of said support frame pivotting about an axis extending in the fore and aft direction of the grader, double acting lift cylinders universally secured to said beam with said lift cylinders located at opposite sides of said frame, a shift cylinder for shifting the opposite end of said drawbar to one side of said frame, and a hydraulic lock arrangement between said beam and said frame, said hydraulic lock arrangement including a hydraulic component to directly maintain the position of said beam and adjust the position thereof by varying said hydraulic component, said hydraulic lock arrangement being secured to said frame at a position to maintain the space below said frame at least substantially unobstructed.

2. In the motor grader of Claim 1, wherein said hydraulic lock is an hydraulic cylinder pivatally secured to said frame and said beam to cause rotation of said beam about said axis by adjusting the length of said cylinder.

3. In the motor grader of Claim 1, wherein said beam includes to one side of said central pivot a downwardly and rearwardly extending projection fixed to said beam cooperating with one end of said shift cylinder.

4. In a motor grader as claimed in Claim 2, wherein the cylinder of said hydraulic lock is mounted on a side portion of said frame and generally extends upwardly.

5. In a motor grader as claimed in Claim 4, wherein said hydraulic lock cylinder is generally vertically disposed and pivotally secured to said frame intermediate its length.

6. In a motor grader as claimed in Claim 2, wherein said hydraulic cylinder is pivotally secured adjacent a lower side region of said frame and secured to said beam generally at a mid region between the point of securement of the adjacent lift cylinder and the pivotal axis of said beam.

7. In a motor grader as claimed in Claim 2, wherein said hydraulic cylinder is disposed at an angle of about 45°
between a lower part of said frame and said beam and is secured to said beam at a position generally at a mid region between the axis of said beam and the point of securement of a lift cylinder to the side of said frame that said hydraulic cylinder is secured.

8. In a motor grader as claimed in Claim 7, wherein said hydraulic lock cylinder extends above said beam to accommodate the required stroke of said cylinder to cause the beam to rotate between its extreme rotation positions.

9. In a motor grader as claimed in Claim 7, wherein said beam is of a fabricated plate steel box construction which includes ports top and bottom which said hydraulic cylinder of said hydraulic lock extends through.

10. A high-lift for a motor grader having a support frame with a drawbar universally secured thereto adjacent the forward end of said support frame and a scraper blade rotatably supported at the opposite end of said drawbar, said high-lift adjustably supporting said blade and comprising a beam pivotally secured atop said frame and rotating about an axis above said frame and extedniding in the longitudinal direction thereof, said beam extending either side of said frame and supporting opposed lift cylinders either side of said frame and below said axis, and means for locking said beam at at least one of three positions at various angles relative to the grader frame, said lock means being located to one side of said frame and pivotally connected to said beam and pivotally connected to said frame on a side thereof, said lock means in combination with said beam and said frame forming a 3 bar linkage which maintain a given position of said beam relative to said frame.

11. A high-lift as claimed in Claim 10, including a downwardly extending arm to one side of said beam and supporting one end of a shift cylinder disposed between said rotatably supported blade and said arm, said arm being angled rearwardly to connect with said shift cylinder at an offset position relative to said axis.

12. A high-lift as claimed in Claim 11, wherein said lock means is a fixed length link having a number of apertures therein for cooperating with a pin member to provide a pin connection with any one of said apertures to lock said beam in one of said given positions.

13. A high-lift as claimed in Claim 12, wherein said fixed length link includes 5 apertures for defining a perpendicular orientation of said beam relative to said frame and positions of about 45 and 63 degrees to either side of said frame.

14. A high-lift as claimed in Claim 11, wherein said lock means is a double acting hydraulic cylinder.

15. A high-lift as claimed in Claim 14, wherein said hydraulic cylinder includes a piston portion and a cylinder portion with said cylinder portion pivotally secured to said frame intermediate the cylinder length, and said piston portion is secured to said arm at a position to maintain a generally vertical orientation of said cylinder.

16. A high-lift as claimed in Claim 14, wherein a piston portion of said cylinder is secured to said frame and a cylinder portion is pivotally secured intermediate its length to said beam and extending at an angle to said frame to reduce the forces at the axis of said beam, the point of securement of said beam and cylinder portion and the point of securement of said piston portion and said frame.

17. A high-lift for a motor grader having a support frame with a drawbar universally secured thereto adjacent the forward end of said support frame and a scraper blade rotatably supported at the opposite end of said drawbar, said high-lift adjustably supporting said blade and comprising a beam pivotally secured atop said frame and rotating about an axis above said frame and extending in the longitudinal direction thereof, said beam extending either side of said frame and supporting opposed lift cylinders either side of said frame and at a spacing of about 50 inches and less than 52 inches, and means for remotely locking said beam at a host of positions at various angles relative to the grader frame, said lock means including an hydraulic double acting lock cylinder located to one side of said frame and pivotally connected to said beam and pivotally connected to said frame on a side thereof, said lock cylinder in combination with said beam and said frame forming a fixed 3 bar linkage to maintain a given position of said beam relative to said frame.

18. A high-lift as claimed in Claim 17, including a downwardly extending arm to one side of said beam and supporting one end of a shift cylinder disposed between said rotatably supported blade and said arm, said arm being angled rearwardly to connect with said shift cylinder at an offset position relative to said beam, said arm in a neutral position of the beam having -the end thereof about nineteen inches below said axis and horizontally offset relative to said axis about sixteen inches.

19. A high-lift as claimed in Claim 17, wherein said lift cylinders are pivotally secured to a support member directly associated with said blade at a spacing of about 48 inches to orientate said cylinders to angle slightly outwardly at the upper portion thereof from the vertical when said beam and said support member are in a neutral position and centered on the longitudinal axis of the frame.

20. A high-lift as claimed in Claim 18, wherein said hydraulic lock cylinder is secured to said beam on an upper surface adjacent one of said lift cylinders which are secured to one side of said beam.

21. A high-lift as claimed in Claim 20, wherein said hydraulic lock cylinder is spaced outwardly of the axis of the beam about 20 inches.

22. In a motor grader having a support frame, a drawbar universally secured thereto adjacent the forward end of the drawbar, and a scraper blade rotatably supported at the opposite end of said drawbar, a beam centrally mounted on top of said support frame pivotting about an axis extending in the fore and aft direction of the grader, double acting lift cylinders universally secured to said beam with said lift cylinders located at opposite sides of said frame, a shift cylinder for shifting the opposite sides of said frame, a shift cylinder for shifting the opposite end of said drawbar to one of said sides of said frame, and a hydraulic lock arrangement between said beam and said frame, said hydraulic lock arrangement including a hydraulic cylinder to directly maintain the position of said beam as desired and adjust the position thereof, said hydraulic cylinder being pivotally secured to one of said sides of said frame and extending upwardly and outwardly and forming a pivotal connection with said beam, said hydraulic cylinder in a neutral position of said beam relative to said frame wherein the beam is generally symmetrically disposed to extend generally equally to either of said sides of said frame being located to said one side of said frame and leaving the area below said frame and to the side of said frame opposite said one side free of obstruction from said hydraulic cylinder.

23. In the motor grader of Claim 22, wherein said beam includes to one side of said fore and aft extending axis a rearwardly and downwardly extending projection fixed to said beam cooperating with one end of said shift cylinder.

24. In a motor grader as claimed in Claim 22, wherein said hydraulic cylinder is pivotally secured adjacent a lower side region of said frame and secured to said beam generally at a mid region between the point of securement of the adjacent lift cylinder and the fore and aft axis of said beam.

25. In a motor grader as claimed in Claim 22, wherein said hydraulic cylinder is disposed at an angle of about 45°
between a lower part of said frame and said beam when said beam is in said neutral position and is secured to said beam generally at a mid region position between the axis of said beam and the point of securement of said lift cylinder to said one side of said frame.

26. In a motor grader as claimed in Claim 25, wherein said hydraulic cylinder extends above said beam to accommodate the required stroke of said hydraulic cylinder to cause the beam to rotate between rotation positions about said fore and aft axis.

27. In a motor grader as claimed in Claim 25, wherein said beam is of a fabricated plate steel box construction which includes ports top and bottom through which said hydraulic cylinder extends.

28. In a motor grader, the motor grader having a support frame with a drawbar universally secured thereto adjacent the forward end of said support frame and a scraper blade rotatably supported at the opposite end of said drawbar, a high-lift adjustably supporting said blade, said high-lift comprising a beam pivotally secured atop said frame and rotating about an axis above said frame and extending in the longitudinal direction thereof, said beam extending beyond either side of said frame and supporting opposed lift cylinders below said axis to either side of said frame and lock means for locking said beam at at least one of three positions at various angles relative to the grader frame, said lock means being located to one side of said frame and pivotally connected to said beam and pivotally connected to said frame on said one side thereof, said lock means in combination with said beam and said frame forming a fixed 3 bar linkage which maintains a given position of said beam relative to said frame.

29. In a motor grader as claimed in Claim 28, including a rearwardly and downwardly extending arm to one side of said beam and supporting one end of a shift cylinder disposed between said rotatably supported blade and said arm, said arm being angled rearwardly to connect with said shift cylinder at a rearward offset position relative to said axis.

30. In a motor grader as claimed in Claim 29, wherein said lock means is a fixed length link having a number of apertures therein for cooperating with a pin member to provide a pin connection with any one of said apertures to lock said beam in one of said given positions.

31. In a motor grader as claimed in Claim 30, wherein said fixed length link incIudes 5 apertures for defining a perpendicular orientation of said beam relative to said frame and positions of about 45 and 63 degrees to either side of said frame.

32. In a motor grader as claimed in Claim 29, wherein said lock means is a double acting hydraulic cylinder.

33. In a motor grader as claimed in Claim 32, wherein said hydraulic cylinder includes a piston portion and a cylinder portion with said cylinder portion pivotally secured to said frame intermediate the cylinder length, and said piston portion is secured to said arm at a position to maintain a generally vertical orientation of said cylinder.

34. In a motor grader as claimed in Claim 32, wherein a piston portion of said cylinder is secured to said frame and a cylinder portion is pivotally secured intermediate its length to said beam and extending at an angle to said frame to reduce the forces at the axis of said beam, the point of securement of said beam and cylinder portion, and the point of securement of said piston portion and said frame.

35. In a motor grader as claimed in Claim 28, wherein said lock means includes a rigid locking link with one end pivotally secured to said beam and secured to said frame at a different position intermediate the length of said rigid locking link by:
means of a pin structure to thereby lock sald beam in one of said at least three positions relative to said frame, said rigid locking link including at least three apertures in the length thereof sized to cooperate with said pin structure to thereby determine the position of said beam relative to said frame.

36. In a motor grader as claimed in Claim 35, wherein said rigid locking link is pivotally secured to a lower portion of said frame to one side thereof and extends upwardly and outwardly at an angle to said frame and connected to said beam at a position generally midway between said axis of said beam and the one of said left cylinder to the same side of said frame as said rigid locking link.

37. In a motor grader having a support frame with a drawbar universally secured thereto adjacent the forward end of said support frame and a scraper blade rotatably supported at the opposite end of said drawbar, a high-lift adjustably supporting said blade and comprising a beam pivotally secured atop said frame and rotating about an axis above said frame, said axis extending in the longitudinal direction of said frame, said beam extending beyond either side of said frame and supporting opposed lift cylinders on either side of said frame and at a spacing of about 50 inches and less than 52 inches, and lock means for remotely locking said beam at a host of positions at various angles relative to the grader frame, said lock means including a hydraulic double acting lock cylinder located to one side of said frame and pivotally connected to said beam and pivotally connected to said frame on said one side thereof, said lock cylinder in combination with said beam and said frame forming a fixed 3 bar linkage which maintains a given position of said beam relative to said frame.

38. In a motor grader as claimed in Claim 37, including a downwardly extending arm to one side of said beam and supporting one end of a shift cylinder disposed between said rotatably supported blade and said arm, said arm being angled rearwardly to connect with sa id shift cylinder at a rearward offset position relative to said beam, said arm in a neutral position of the beam having the end thereof about nineteen inches below said axis and horizontally offset relatlve to said axis about sixteen inches.

39. In a motor grader as claimed in Claim 38, wherein said hydraulic lock cylinder is secured to said beam on an upper surface thereof adjacent one of said lift cylinders which is secured to one side of said beam.

40. In a motor grader as claimed in Claim 39, wherein said hydraulic lock cylinder is spaced outwardly of the axis of the beam about 20 inches.

41. In a motor grader as claimed in Claim 37, wherein said lift cylinders are pivotally secured to a support member directly associated with said blade at a spacing of about 48 inches to orientate said left cylinders so as to angle slightly outwardly at the upper portion thereof from the vertical when said beam and said support member are in a neutral position and centered on the longitudinal axis of the frame, said beam in said neutral position being generally symmetrically disposed to extend generally equally to either of said sides of said frame.