WO1980000857A1

WO1980000857A1 - Boom arm with rock deflection feature

Info

Publication number: WO1980000857A1
Application number: PCT/US1979/000780
Authority: WO
Inventors: R Anderson; T Cameron
Original assignee: International Harverster Corp
Current assignee: International Motors LLC
Priority date: 1978-10-12
Filing date: 1979-09-24
Publication date: 1980-05-01
Anticipated expiration: 1981-04-12

Abstract

A loader vehicle boom arm assembly incorporates a pair of box section boom arms (42, 44) in which the top plate (52) of each box section boom arm has a cross sectional shape such that the upper surface is provided with an arcuate surface (80) that directs foreign objects encountering the arcuate top surface off the boom arm.

Description

BOOM ARM WITH ROCK DEFLECTION FEATURE

BACKGROUND OF THE INVENTION Field of the Inventio . The invention has to do with the shape of loader boom arms or lift arms. More specifically, the invention is primarily a rock deflecting top plate used on loader boom arras. The top plate is roll formed with a cross sectional shape to provide a J-groove weld bed and to provide a contoured or arcuate top surface.

Description of the Prior Art_

Construction equipment used in excavating, mining, land reclamation, and other typical situations where a bucket mounted to the boom arras of -a loader vehicle is used to load or transport material is subjected to extremely hard use and unusual encounters with the environment. It is common to see a significant amount of spillage as a bucket is initially loaded by an aggressive operator, however, in the interest of efficiency this spillage usually occurs as the bucket is loaded and thus spills back into a source pile.

Some spillage may also occur when transporting a full load of unstable material at speed across a construc- tion site. Also some spillage may occur as the bucket is raised preparatory to it being dumped into the bed of a dump truck or a hopper. The invention is directed to minimizing damage from this type of spillage.

The invention disclosed herein may be used on loader vehicles having box beam type boom or lift arms. The

,_. OMPI prior art box section boom arms are typically made either channel section left and right side members that are weld together at the edges thereof to form the box or alterna¬ tively of four plates, two plates being side plates and o of each the others being respective top and bottom plates In these two embodiments the top surface has always been relatively flat surface.

It has been found that the top plate upper surf of the box section boom arms will occasionally provide a path that spillage from the loader bucket will follow if material should happen to fall out of the bucket when the bucket is raised to an elevated position. Material spill out of the bucket-may fall onto^' the top surface of the loader arm and travel down the loader arm a significant distance. If a rock, for instance, falls out of the buck onto the top of the boom arms there is some potential tha the rock will roll down the length of the boom arm and contact the vehicle in an area not provided with structur strength sufficient to be undamaged by the impact of the rock.

One of the more typical solutions to the proble would be to provide the bucket with a load containing extension that would contain any possible spillage. Anot possible solution would be to weld vertical transverse barriers across the top of the boom arms. A further solu tion would be to weld a longitudinal vertical fin along t entire length of the top surface of the boom arm. It is known whether these solutions exist in the prior art, how ever, it is felt that they may be obvious. Unfortunately each of these solutions require extra operations in the fabrication of the boom while execution of the invention disclosed in this specification can provide a rock deflec integral with the boom arm top plate at no additional cos over a conventional top plate.

SUMMARY OF THE INVENTION A box beam boom arm is provided with a top plat having a transverse cross sectional shape providing an

OM

_- -__ i arcuate crown surface to direct any material inclined to roll longitudinally down the top plate off the top plate.

The top plate is also provided with contoured edges that when assembled to the sidewalls of a box beam boom arm form a J-groove weld bed providing a multitude of advantages.

One of the objects of this invention is to provide a box beam boom arm that has a shape on an upper surface thereof that discourages loose material from remaining on the top surface of the boom arm.

Another object of this ^'invention is to provide a material deflection means that can be incorporated into the design of the boom arms without any appreciable increase in boom arm manufacturing cost. It is also an object of this invention to provide material deflection means that is aesthetically pleasing and unobtrusive i*n its incorporation into the boom arm assembly.

These and other objects and advantages will become apparent from an understanding of this disclosure.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIGURE 1 is an elevation view of a loader vehicle incorporating the invention;

FIGURE 2 is an elevation view of a boom arm utilized in Figure 1 before the components of the boom arm have been welded together;

FIGURE 3 is a top view of a boom arm assembly showing a pair of boom arms connected together by a torque tube; and FIGURE 4 is a cross sectional view of a portion of a boom arm as taken through a plane 4-4 of Figure 2.

DETAILED DESCRIPTION OF THE INVENTION The excavating loader shown generally as 10 in Figure 1 is an example of a typical mobile material handling vehicle that would incorporate the invention. A boom arm assembly generally 12 is pivotally mounted at pivot point 14

'BUREAU

OMPI - WIPO ,κ . to the front portion 16 of the conventional articulated loader. A boom lift cylinder 20 is pivotally grounded to the front portion of the loader at 22 and pivotally mounte to the boom arm assembly generally 12 at pivot point 24. Bucket actuating cylinder 26 is pivotally grounded to the front portion of the vehicle and the rod thereof is pivota ly connected to the bell crank 30 which is pivotally sup¬ ported on the cross tube extensions 32 which are integral with the boom arm assembly generally 12. A bucket link 34 is pivotally mounted at its respective ends to the lower pivot point of the bell crank and a pivot point on the bucket 36. The bucket 36 is pivotally mounted to the boom arm assembly at pivot point 40. Figure 2 presents a side elevation view of the general boom arm assembly that has t various parts located in the final positions relative to each other but have not yet been finally welded together. The figure shows the outboard side of the right side boom arm 42 of Figure 3 but is intended to be representative of identical parts on the left side boom arm 44 as well as th cross tube extension 46 and 50.

The side wall 54 is cut from plate stock such th the upper edge 56 and the lower edge 60 presents surfaces that are perpendicular to the outboard surface, i.e., the surface that is seen as contrasted in the inboard surface the sidewall which constitutes the inner walls of the box beam. Each end of the boom arm is provided with a boom ar end 62 and 64, in this embodiment shown as castings, which are provided with through bores to accommodate pins attach ing the boom arm to the loader frame 16 and the bucket 36. A boom pocket casting 66 is positioned in the lower sectio of the boom arm and is welded to the inboard (not seen) an outboard 54 sidewall as well as to the adjacent ends of th forward bottom plates 70 and the rear bottom plates 72. A cross tube 74 that supports right 46 and left 50 (Figure 3 cross tube extension is welded to the inboard sidewalls 76 on the left and right side boom arms. The crux of this invention has to do with the cross sectional shape of the top plate 52, its method of manufacture, and the method of attaching the top plate to the sidewalls of the box beam boom arm. Many aspects of this invention are disclosed in a disclosure entitled "Integral Box Section Boom Arm" invented by Thomas M. Cameron filed the same day in this disclosure and assigned to the same assignee as this invention. The related disclosure is incorporated into this disclosure except relative to obvious inconsistencies.

Figure 4 presents a cross sectional view of a portion of a boom arms is taken through plane 4-4 of Figure 2. This figure shows the modified top plate 52 in the rock deflecting surface or crown 80. The top plate 52 is posi¬ tioned between the inboard surface of the inboard sidewall and the inboard surface of the outboard sidewall 54. Weld beds 82 and 84 are formed between the top plate 52 and edges of the sidewalls 76 and 54 such that welds 86 and 90 can be provided to attach the top plate 52 to the sidewalls. A locating piece 92 may be welded to the inner surfaces of each sidewall to temporarily hold them in relative alignment until final welding of the entire boom arm is completed.

The locating piece 92 may also serve to locate the top plate to ensure that a weld bed of appropriate dimensions is maintained.

The cross sectional shape of the top plate is critical to this invention. The top plate is provided with an arcuate crown 80 on an uppermost surface of the plate. This surface slopes downward from the exterior surface center of the top plate to the edges. The overall width from edge-to-edge of the top plate is the same as the ex- ternal sidewall to sidewall dimension of the box boom arm. The crown effect is carried out throughout the entire longi¬ tudinal length of the top plate. The bottom or inboard surface of the top plate is generally a flat surface. The^' transverse length dimension of this portion of the top plate is equivalent to the distance between the inboard surface of the sidewalls. The edge of the sidewalls are mirror images of each other and they are stepped inwardly from the widest

_ 0MPI_ part of the top plate to the narrowest part of the top plate. The inward step is provided by bevelled surfaces 9 and 100 as shown.

The bottom plates, forward 70 and rear 72, are formed similar to the top plate, however, they have a flat outboard surface as the rock deflecting aspect of the top plate is not needed on the bottom plate. The use of a bott plate having the same cross sectional shape as the top pla has been considered and may prove beneficial from a cost standpoint even though no rock deflecting benefit can be derived.

The top plate and the bottom plate are roll form through a series of progressive dies hence the final cross sectional shape can be slightly revised by replacing only portion of the dies. This leads to obvious economies when it is desirable to slightly alter the shape of the plates provide a basis for di ensionally different box beam boom arms.

The operation of the rock deflecting feature of this top plate has been described earlier in this disclosu The solution can be more easily envisioned through a revie of Figures 3 and 4. A rock that falls out of the bucket, it is being elevated, onto the uppermost or crown 80 surfac of the top plate will tend to roll off the top plate due to the shape of the crown rather than follow the boom arm toward the boom arm assembly mounting points at the front portion of the vehicle.

It is apparent that a boom arm assembly fully satisfies the objects, aims and advantages as set forth above. While the invention has been described in conjunc¬ tion with a specific embodiment thereof it is evident that alternatives, modifications and variations may be apparent to those skilled in the art in light of the foregoing de¬ scription. For instance as pointed out in the specifica- tion the cross sectional shape of the top plate could also be used on a bottom plate of a boom arm for ecconomic con¬ siderations. Alternative host vehicles may also advanta- " geously use the described structure. Accordingly, this disclosure is intended to embrace modifications and varia¬ tions falling within the spirit of the appended claims.

Claims

What is claimed is:

1. A box section boom arm pivotally mounted to mobile material handling vehicle for accommodating a rais- able implement, the boom arm comprising: a first sidewall having an upper and a lower edg a second sidewall having an upper and a lower ed spaced apart from and longitudinally aligned with said fir sidewall; a^" top plate welded to said upper edges of said first and said second sidewalls to join them together, sai top plate having a transverse cross sectional shape that h a flat inboard surface and an arcuate outboard surface and edges that are stepped down from the outboard surface to t inboard surface of said top plate; a bottom plate welded to said lower edges of sai first and second sidewalls to join them together, said bottom plate having a transverse cross sectional shape having inboard and outboard surfaces and edges that are stepped down from the outboard surface to the head board surface of said arm plate.

2. The invention in accordance with Claim 1 wherein said bottom plate has a transverse cross sectional shape having flat parallel inboard and outboard surfaces a edges that are stepped down from the outboard surface to t inboard surface of said bottom plate.

3. The invention in accordance with Claim 1 wherein said bottom plate has a transverse cross sectional shape that has a flat inboard surface and an arcuate out¬ board surface.

4. The invention in accordance with Claim 1 wherein a weld bed for receiving a continuous weld is form along the upper and lower edges of said first and second sidewalls at the respective inner sections of said top and bottom plates, said weld bed being a J-groove defined by said sidewall edges and said edges of said top and bottom plates.

5. The invention in accordance with Claim 1 wherein said box section boom arm further comprises; a pair of boom arm ends, one boom arm end welded to each end of said box section boom arm, .each boom arm end being a casting having a through bore.

6. The invention in accordance with Claim 5 wherein said box section boom arm further comprises; a boom pocket casting welded to the lower edge of said first and second sidewalls, said boom pocket casting having a through bore.

7. A boom arm assembly for use on a loader vehicle comprising: a pair of boom arms each boom arm comprising; a first sidewall having an upper and a lower edge; a second sidewall having an upper and a lower edge spaced apart £rom and longitudinally aligned with said first sidewall; a top plate welded to said upper edges of said first and said second sidewalls to join them together, said top plate having a transverse cross sectional shape that has a flat inboard surface and an arcuate outboard surface and edges that the stepped down from the outboard surface to the inboard surface of said top plate; a pair of bottom plates identified as forward and rear bottom plates, each welded to said lower edges of said first and second sidewalls to join them together, said bottom plate having a transverse cross sectional shape that has inboard and outboard surfaces and edges that are stepped down from the outboard surface to the inboard surface of said bottom plates; a pair of boom arm ends one boom arm end welded^' to each of said box section boom arms each boom arm end being a casting and having a through bore; a boom pocket casting welded to said lower edge of said first and said second sidewalls between said forward and said rear bottom plates, said boom pocket casting havi a through bore; a torque tube connecting one pair of said pair o boom arms to the other of said pair of boom arms.