US3736987A - Outrigger boom for earthworking vehicles - Google Patents

Abstract

An outrigger boom has an elongated, angular support cradle which can be attached to an earthworking vehicle or its movable earthworking element and a telescoping boom assembly having its inner end pivoted on the inboard end of the cradle so that the boom assembly can be aligned with the cradle and tightly clamped therein when in use to rigidly couple them so a universally adjustable mounting device at the outer end of the boom assembly can attach and orient sensing transducers whereby external references can be utilized for control system reference even though such references are located somewhat remote to the vehicle''s operating area.

Description

11 3,736,937 .lune 5, 1973 United States Patent 1 Easterling 3,495,663 2/1970 Scholl et al.......................1....l72/4 5 3,627,057 12/1971 Hartwigetal........................172/126 [54} OUTRIGGER BOOM FOR EARTHWORKING VEHICLES [75] Inventor: Gene B. Easterling, Decatur, Ill.

[73] Caterpillar Tractor Co.

Nov. 22, 1971 21 Appl. No.: 201,087

Primary Examiner-Robert E. Pulfrey Assistant Examiner-Stephen C. Pellegrino Atr0rneyJoseph L. Strabala Peoria, 111.

Assignee:

Filed:

[52] US. Cl. ......................l72/4.5, l72/4.5, 172/26,

[51] Int. Cl. 63/111,

Field of Search.......................

pivoted on the inboard end of the cradle so that the boom assembly can be aligned with the cradle and tightly clamped therein when in use to rigidly couple them so a universally adjustable mounting device at [56] References cued the outer end of the boom assembly can attach and UNITED STATES PATENTS orient sensing transducers whereby external references can be utilized for control system reference t a h w e m 0 S w S m n ma u 1w m m g m .m cm Cr. me D 4 r m m .l mm m u C SV 5 m W t om. me m n m em 8 V XX w sj 44 M NU J HH Hickey 4/1969 lverson.............................

rS .mm we EM 560 456 999 111 90 1 6556 6344 13 4725 8623 3 .9 2223 Patented June 5, 1973 3,736,987

2 Sheets-Sheet 1 INVENTOR GENE B. EASTERLING W41 21,4; 7414 wi-qw' ATTORNEYS Patented June 5, 1973 2 Sheets-She at 2 INVEN'R )R GENE B. EASTERL ING OUTRIGGER BOOM FOR EARTIIWORKING VEHICLES BACKGROUND OF THE INVENTION Specifications in earthworking grading and finishing operations often require the finished grade and slope to be within one-eighth of an inch of those prescribed. In the past only highly skilled operators of earthworking machines, such as motor graders, could finish grades and slopes to such exacting parameters. Currently grading machines are now in use which automatically control their earthworking implements to achieve such exacting standards by sensing various external references to serve as primary inputs into the control system in order to achieve the necessary control information. A blade control system for a motor grader described in US. Pat. No. 3,486,564 issued to Page et al. is amply illustrative of automatic blade control systems used for motor graders and some of the types of external references used for such controls are described in US. Pat. No. 3,495,663, issued to Scholl et a1. Such references are often wires strung along the work course of the vehicle that are accurately placed by surveying, or alternatively they may be finished surfaces contiguous to the work course on which the grading operations are being accomplished.

As can be appreciated, the cost of providing some of these temporary references, such as the surveyed wires strung along a work course, is expensive. If an adjacent finished or graded surface having known specification can be utilized as a reference, further economies can be experienced with automatic blade control and like systems. However, because it is conventional to attach the sensing transducers directly on the end of the grader moldboard or similar earthworking implement, such as shown in the above-mentioned patents, it usually necessitates that the wire be strung extremely close to the existing work course and that no obstructions exist between the end of the moldboard and the external reference so the sensing elements of the transducers can track the reference without interference. Of course, with a wire reference strung close to the work course the operator of the vehicle must be careful to avoid disrupting the surveyed wire and also must keep the end of the moldboard extremely close to the wire so that the sensing elements can obtain a reference therefrom thereby restricting its positioning.

Thus, a principal object of the instant invention is to increase the flexibility of an earthmoving vehicle by giving it the capability to use external references somewhat remote of the vehicle by providing a fully adjustable outrigger boom to mount sensing transducers in a cantilevered manner from the vehicle so that somewhat remote external references can be utilized by earthworking vehicles having automatic control systems or reference reading systems for achieving exacting standards in grading and finishing operations.

It is also an object of this invention to provide an outrigger boom which is a sufficiently stable support when mounting sensing transducers in a cantilevered arrangement so that vibrations, deflections and or distor tions in the boom will not introduce substantial error into the condition sensed by the transducer and also a boom which also can be folded to a stowed position, when not in use, thereby increasing vehicle flexibility.

SUMMARY OF THE INVENTION To achieve the above objects and advantages an adjustable outrigger boom for an earthmoving vehicle supporting sensing transducers in a cantilevered arrangement from such vehicles includes an elongated angled support cradle fixedly attached to the vehicle or its earthworking implement and mounted so that one of its ends projects therefrom, with the support cradle having a clevis connection at its inner end, a telescoping boom assembly having an outer tubular member with one end pivoted in the clevis connection so it can be swung into parallel alignment with the support cradle with the boom also having at least one inner tubular member telescoped within the outer tubular member and selectively lockable therewith against relative movement and a clamp engageable with the outer end of the support cradle and operable to wedge the outer tubular member into the support cradle for maximum rigidity of the boom when in use which also allows the boom assembly to be conveniently released from the cradle and stowed in a protected location when not in use. At the end of the boom assembly is a universal attaching device through which various sensing transducers mounted thereon can be selectively oriented and locked in such orientations so their sensing elements will track on external references, such as finished road surfaces, surveyed wires and the like. Obviously a number of different sensing elements, such as wands or soft pneumatic tires, may be utilized to operate the transducers.

DESCRIPTION OF THE DRAWINGS FIG. I is a perspective of a motor grader having the outrigger boom mounted thereon in its operating position with a transducer mounted on its outer end;

FIG. 2 is a cross section of the outer end of the boom and support cradle, illustrating how the boom is locked in the cradle with a clamp for maximum boom rigidity;

FIG. 3 is a broken-away partial section of the universal attaching unit at the distal end of the boom assembly; and

FIG. 4 is a broken-away sectional view along line IV-IV of FIG. 1 showing additional detail of an extension unit for remote positioning of a sensing transducer.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. I, a motor grader 10 is illustrated having a drawbar 1 l universally connected in its bolster l2 and supported from the arched frame 13, extending rearwardly from the bolster, through lift arms 14 journalled on the frame and hydraulic jacks l5 linking the ends of the lift arms to the drawbar frame. In turn the bottom of the bolster is supported on steerable front wheels 16 and the rear portion of the arched frame is attached to the tractor unit 17 of the grader that is supported by rear wheels 18. In the above manner the drawbar is suspended under the arched frame so it can be adjusted by actuation of either the jacks or the lift arms for full maneuverability of its moldboard.

Mounted underneath the drawbar I1 is a circle 19 which is secured thereto in a conventional manner using C-shaped brackets (not shown) attached to the drawbar which support the circle therebeneath for rotation, so that its inner teeth 20 can be engaged by drive unit 21 to rotate the circle about its center. Two spaced apart downwardly oriented shanks 22 support the moldboard 23 from the circle in a conventional manner on slide shoe brackets so that the moldboard can be side shifted through operation of jack 2 and so its top edge can be oscillated fore and aft to adjust the pitch of its cutting edge.

Thus, the moldboard can be conveniently controlled for cutting and grading operations and is usually stabilized by a drag link mounted angularly from the drawbar to the grader frame so that the moldboard or blade positions will be precisely maintained.

By connecting valves operating the hydraulic jacks to an automatic blade control system, such as the blade control systems described in the afore-mentioned US. Pat. Nos. 3,486,564 and 3,495,663, the moldboard can be continuously adjusted with regard to both slope and grade to perform precise and accurate finish grading operations. As can be seen in the disclosure of the afore-mentioned patents, the sensing transducers for grade for grade and/or slope control are mounted at the ends of the moldboard in order to sense the position of a surveyed wire reference strung along the work course or other external reference adjacent thereto. Thus, when the moldboard can be operated closely adjacent to such. external references so they can be reached by wands or the like operating the transducers on the end of the moldboards, the automatic blade control system described above, will operate satisfactorily. However, if the external reference is located some distance or remote from the work course or if the moldboard must be manipulated in a manner because of existing conditions, whereby it cannot be positioned closely adjacent to such external references, such automatic blade control cannot be effectively utilized. Thus, the instant invention is designed to increase the flexibility of automatic blade control systems in motor grader and like applications in the earthmoving field by providing cantilevered remote mounting for sensing transducers.

An outrigger boom 30, according to this invention, is used to mount the sensing transducers closely adjacent to remote external references whereby additional flexibility can be obtained with automatic blade controls in motor graders and the like. Universally adjustable, this boom includes an elongated angle support cradle 31 which is welded or bolted directly to the drawbar 11 so that one of its ends projects outwardly from the drawbar as shown in FIG. 1, and in this embodiment, the support cradle is attached directly to the movable earthworking moldboard of the motor grader which is accomplishing the cutting and finishing operations through the drawbar connection. At the inboard end of this cradle is a clevis connection and an angle support cradle may be located on both sides of the drawbar so that the outrigger boom can be simply changed to the opposite side of the grader if desired, and each cradle has a forwardly oriented strut 33 connecting its outboard end to a central portion of the drawbar forward of the support cradle to increase its stability.

The main boom assembly 34 consists of three telescoped, cylindrical tubes with the outer tube 35 having its inboard end fitted into the clevis connection and secured therein with bolt 36 so that this portion of boom assembly can be cradled in the angled support cradle 31 or swung forwardly so that it parallels the drawbar frame where it can be secured on a bracket 37 when not in use, thereby avoiding interference with other types of grader operations. When the outer tube is cradlecl in the angled support cradle, an angle clamp 38 having ears 38a engaging the outer surfaces of the cradle and having a wedging bolt 38b threaded in its reinforced corner 38c so it bisects the apex of this corner, can be assembled therewith so that its wedging bolt will tighten against the surface of the outer tube, wedging it into the corner of the support cradle, thereby achieving a maximum rigidity between the outer tube and the cradle as can best be seen in FIG. 2. This arrangement allows the outer tube to be fixedly secured against all movements and distortions with respect to the drawbar when clamped in the support cradle and yet allows it to be simply released and swung forward through the pivot formed by the clevis connection when it is desired to stow theboorn assembly when it is not in use.

Telescoped within the outer tube 35 is an intermediate tube 39 that snuggly fits therein and can be selectively locked in any extended position with a lock bolt 40 threaded radially into the outer tube to abut against the surface of this intermediate tube when tightened. Telescoped within the intermediate tube is the outboard tube 41 of the boom assembly which can be locked against relative movement with the intermediate tube with a lock bolt 42, in the same manner as the intermediate tube is locked with the outer tube in the inboard portion of the boom assembly. Through this arrangement a telescoping boom assembly is provided which, when clamped into the cradle with its several tubes locked against movement, provides a relatively stable boom unit having little distortion and deflection between its mounting on the drawbar l1 and its distal end. Obviously the cylindrical structure of the telescop ing parts of the boom provide a relatively stable arrangement against deflection. However, to some extent, as the boom is extended, deflection thereof may increase slightly.

At the distal end of the outboard tube 41 is a ball 43 that fits into a socket 44 which can be tightened with bolts 440 (See FIG. 3) to lock the ball and socket together as an integral unit once an adjustment of the socket has been made relative to the boom assembly. On the socket is an attachment bracket 45 having an angle pad 45a on which an angled clamp 46, identical to angle clamp 38 but smaller in size, is employed to tightly secure an extension post 47 therein with its wedging bolt 46a. Alternatively, the transducer can be mounted in this bracket. The post forms an extension from the universal adjusting device formed by the ball and socket connection at the distal end of the boom whereby sensing transducers can be further displaced relative to the end of the linear boom in order to conveniently reach external references above or below the boom assembly.

A cross clamp 48, best shown in FIG. 4, includes two angle pads 48a and 48b transversely oriented with respect to one another and respectively cooperating with angle clamps 49 and 50, which are similar to angle clamps 38 and 46, to lock the cross clamp to post 47 and to an arm 51 of a transducer unit 52 secured to the bottom of the post with the cross clamp. Instead of the lock bolts used for angle clamps 38 and 46, angle clamps 49 and 50 use threaded lugs 49b and 50b that function like the lock bolts but which can be tightened and loosened by hand due to their L-shaped configuration.

With all of the aforesaid adjusting devices secured tightly so the boom is locked rigidly in the cradle and all joints between the cradle and the transducer units locked against movement, the boom assembly will have very little deflection or distortion when sensing external references with transducers mounted on the end of the boom assembly or the extension formed by post 47, since very little boom load is experienced during such sensing operation. Further, it can be appreciated that the orientation of the transducer unit can be universally varied by virtue of the afore-described adjustments and connections, thereby enabling the transducer unit to reach, within reason, any external reference within a limited area along the grader work course.

For purposes of illustration a wheel-type transducer unit 52 is shown in the drawings and a transducer unit of this type is more detailed in the afore-mentioned U.S. Pat. No. 3,495,663, issued to Scholl et al. In such a unit yoke 53 is swingably connected to its mounting arm 51 so that the soft tire 54, supported in fork 55, can track on a previously finished or graded surface for purposes of establishing external reference by which an automatic grader control can be operated. In the transducer described, the fork is pivoted in the yoke so that it will turn the wiper arm of a potentiometer (not shown) in order that vertical movements of the fork will generate a signal proportional to such movement of the tire-on the external reference surface, thereby providing the necessary output signal information.

The output signal from the potentiometer is conveyed from the transducer via cable 56 strung on the boom to the control system. It should be appreciated that instead of a fork 55, a wand could be pivoted in the yoke and track on a wire or similar surface to provide the necessary output signal information.

What is claimed is:

1. In an earthworking vehicle having a movable earthworking element anoutrigger boom for supporting sensing transducers remote of the vehicle in a cantilevered arrangement comprising:

an elongated support cradle fixedly attached to said earthworking element with its outer end projecting therefrom, said support cradle having a clevis connection at its inboard end and fixedly joined to said earthworking element to move therewith;

a telescoping boom assembly having an outer tubular member and at least one inner tubular member snuggly telescoped in said outer tubular member with locking means selectively securing said tubular members against relative movement, said outer tubular member having its inboard end pivoted in said clevis connections;

clamping means engageable with said support cradle and operable to wedge said outer tubular member into said support cradle when the former is aligned with the latter to rigidly lock them together as a unit; and

universal adjusting means mounted at the distal end of said boom assembly operable to selectively orient sensing transducers mounted thereon at loca tions remote from said earthworking element whereby said sensing transducers may accurately register deviations between said earthworking element and an external reference on which said sensing transducers are tracking.

2. The outrigger boom described in claim 1 wherein the movable earthworking element is a moldboard supported from a drawbar and the vehicle is a motor grader.

3. The outrigger boom described in claim 2 wherein the angled elongated support cradle is formed from angle iron and includes a brace member connecting its outer end to the drawbar to increase the end stability of said support cradle.

4. The outrigger boom described in claim 1 wherein the universal adjusting means mounted at the end of the boom assembly includes a lockable ball and socket unit which allows universal orientation of sensing transducers mounted therein.

5. The outrigger boom described in claim 4 wherein the universal adjusting means includes an extension means for mounting sensing transducers remote thereof, whereby said sensing transducers can be located off the axis of the boom assembly to track references above and below said axis.

Claims (5)

1. In an earthworking vehicle having a movable earthworking element an outrigger boom for supporting sensing transducers remote of the vehicle in a cantilevered arrangement comprising: an elongated support cradle fixedly attached to said earthworking element with its outer end projecting therefrom, said support cradle having a clevis connection at its inboard end and fixedly joined to said earthworking element to move therewith; a telescoping boom assembly having an outer tubular member and at least one inner tubular member snuggly telescoped in said outer tubular member with locking means selectively securing said tubular members against relative movement, said outer tubular member having its inboard end pivoted in said clevis connections; clamping means engageable with said support cradle and operable to wedge said outer tubular member into said support cradle when the former is aligned with the latter to rigidly lock them together as a unit; and universal adjusting means mounted at the distal end of said boom assembly operable to selectively orient sensing transducers mounted thereon at locations remote from said earthworking element whereby said sensing transducers may accurately register deviations between said earthworking element and an external reference on which said sensing transducers are tracking.

2. The outrigger boom described in claim 1 wherein the movable earthworking element is a moldboard supported from a drawbar and the vehicle is a motor grader.

3. The outrigger boom described in claim 2 wherein the angled elongated support cradle is formed from angle iron and includes a brace member connecting its outer end to the drawbar to increase the end stability of said support cradle.

4. The outrigger boom described in claim 1 wherein the universal adjusting means mounted at the end of the boom assembly includes a lockable ball and socket unit which allows universal orientation of sensing transducers mounted therein.

5. The outrigger boom described in claim 4 wherein the universal adjusting means includes an extension means for mounting sensing transducers remote thereof, whereby said sensing transducers can be located off the axis of the boom assembly to track references above and below said axis.

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