SCRAPER BOWL STRUCTURE

Technical Field

This invention relates to earthmoving scrapers and the like wherein earth is scraped into a bowl for transport to a disposal site.

Background Art

Conventional scraper bowl structures typi¬ cally include a pair of sidewalls, a forwardly extend- ing bowl floor, a rear ejector, and a front apron. In operation, the entire bowl structure, including the sidewalls, is pivoted around the supporting rear wheels from a raised load-carrying position to a low¬ ered loading position. In the loading position, the front edge of the rigid bowl floor scrapes earth into the rear portion of the scraper bowl structure until the desired load is obtained, whereupon the apron is pivotally lowered to close the bowl structure and the entire bowl structure pivotally raised to the load- carrying position. Upon reaching the desired site, the bowl structure is pivotally lowered, the apron raised, and the ejector urged forwardly to displace material from the rear of the bowl structure.

While the aforementioned scraper bowl struc- ture has been widely accepted, it is relatively com¬ plex and costly in construction. In addition to re¬ quiring movement of the ejector and apron, the entire bowl structure must be pivotally raised and lowered, and this leads to complex supporting systems at the front end thereof. For example, pairs of undesirable draft arms extend around the sidewalls of the bowl structure so that the bowl structure can be pivotally

raised and lowered, and expensive hydraulic jacks are required to perform this function.

Another problem with conventional scraper bowl structures is that, in the loading mode, earth enters over the cutting edge of the bowl floor and soon accumulates such that earth is forced upwardly against earth. This frictional retardation requires more loading energy and is time-consuming.

U. S. Patent No. 2,567,534 to C. Whittier on September 11, 1951, discloses one bowl structure having a rear blade that advantageously loads onto a front apron. However, the rear blade is rigidly se¬ cured to the supporting frame so that it is necessary to pivotally raise and lower the bowl supporting frame. This requires an undesirably complex and cost¬ ly construction.

U. S. Patent No. 2,858,627 to A. J. Brown et al on November 4, 1958, discloses another bowl structure desirably having only a movable front apron bowl and a movable rear main loading bowl. But, the support therefor must also be raised and lowered, and earth soon accumulates at the front edge of the rear bowl during loading until the entire mass must be forced upwardly and rearwardly in much the same way as a more conventional bowl structure.

Accordingly, what is desired is a scraper bowl structure which does not have to be raised and lowered as a unit, which has a relatively few number of pivotal components, and which can be relatively easily loaded and unloaded for effective economy of operation and the saving of energy.

Disclosure of Invention

The present invention comprehends an im¬ proved scraper bowl structure wherein the apron and

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blade are pivotally mounted between horizontally spaced fixed sidewalls and are selectively positionable in a scraping arrangement, a load-carrying arrangement, and a load-discharging arrangement. The scraper bowl structure of the present invention is extremely simple and economical of con¬ struction while providing effectively minimum struc¬ tural weight requirements so as to permit increased payload of the scraper vehicle and/or permit reduc- tion in the horsepower requirements of the tractive unit.

More specifically, the invention comprehends the provision of an improved blade structure for use in a scraper bowl structure of the type having a pair of upright sidewalls, frame means for supporting and maintaining the sidewalls in a substantially fixed el- evational relationship to the earth, and a concave apron pivotally connected to the sidewalls and being movable between raised and lowered positions there- between. The blade structure is defined by a concave blade pivotally connected to the frame means and be¬ ing movable between raised and lowered positions be¬ tween the sidewalls, the blade being of a construc¬ tion sufficient for bulldozing earth forwardly onto the apron in the lowered position of the blade and apron.

A number of spreader members may be pro¬ vided extending between the spaced sidewalls which may cooperate with the apron and blade in supporting the same in different positions thereof.

In the illustrated embodiment, a push frame is provided at the rear of the bowl structure, the blade being pivotally mounted to the push frame.

The second positioning means is arranged to dispose the blade in the scraping disposition with

the apron being disposed in the retracted disposition. In the illustrated embodiment, the apron and blade are generally segmentally cylindrical so as to cooperatively define, with the sidewalls, a generally semicylindrical, upwardly open load space when the apron and blade are disposed in the load-carrying disposition.

In the illustrated embodiment, the cutting edge engages a rear edge portion of the apron when the apron and blade are concurrently disposed in the load-carrying disposition.

The sidewalls are arranged to extend gener¬ ally horizontally at all times.

In the illustrated embodiment, a substantial portion of the apron is disposed above the level of the top of the sidewalls when the apron is disposed in the retracted disposition.

Thus, the scraper bowl structure of the present invention is extremely simple and economical of construction comprising essentially a pair of spaced sidewalls, a first movable bowl-forming mem¬ ber in the form of an apron, and a second bowl-form¬ ing member in the form of a blade. The bowl-forming elements are arranged in a novel manner to provide selectively the desired scraping, load-carrying and load discharging functions desired in such scraper structures.

Brief Description of the Drawing

FIGURE 1 is a side elevation of a scraper vehicle embodying the invention;

FIGURE 2 is a- fragmentary enlarged side ele¬ vation partially in section illustrating the arrange¬ ment of the structure as during a scraping operation; and

FIGURE 3 is a view similar to that of Figure 2 but with the elements of the. bowl structure arranged as during a load-discharging operation.

Best Mode for Carrying Out the Invention In the illustrated embodiment of the inven¬ tion as disclosed in the drawing, a scraper vehicle generally designated 10 is shown to include a scraper bowl structure generally designated 11 supported rear- wardly on a wheeled support generally designated 12 and forwardly on a gooseneck 13 connected through a hitch 14 to a wheeled tractive apparatus generally designated 15.

The present invention is concerned with the construction of the scraper bowl structure 11. More specifically, the bowl structure includes a pair of sidewalls 16 and 17 which are secure.d in spaced-apart relationship by a front spreader tube 18, a rear spreader tube 19, a front spreader bar 20, and a rear spreader bar 21. A front apron 22 is pivotally mounted by means of arms 23 to the sidewalls 16 and 17 by suit¬ able pivots 24.

A rear blade 25 is pivotally mounted between the sidewalls 16 and 17 by means of a pair of arms 26 pivotally connected to pivots 27 on a rear push frame 28 of the wheeled support 12. Thus, the illus¬ trated embodiment, the vehicle front and rear frame means generally designated 36 includes support 12, gooseneck 13, hitch 14, tractive apparatus 15, tube 18, tube 19, bar 20, bar 21, and rear frame 28.

A pair of hydraulic cylinders 29, disposed outboard of sidewalls 16 and 17 at opposite sides of the scraper, are connected to the front apron 22 for swinging the apron selectively about pivots 24.

A pair of hydraulic cylinders 30 are connected between sidewalls 16 and 17 and the rear blade 25 for swinging the blade selectively about pivots 27.

Suitable controls 31 are provided in the tractive unit 15 for selectively operating the hy¬ draulic cylinders, as further discussed below.

As shown in Figure 1, apron 22 and blade 25 may be cooperatively arranged in a load-carrying dis¬ position to support the scraped material 32 as for transfer of the material 32 to a delivery site from the loading site. In the load-carrying disposition, the upwardly opening concave apron 22 and upwardly facing concave blade 25 cooperatively define, with the sidewalls 16 and 17, a generally semicylindrical, up- wardly opening load space 33. As shown in Figure 1, apron 22 is generally segmentally cylindrical.

Blade 25 may be provided with a cutting edge portion 34 which is juxtaposed to the rear edge por¬ tion 35 of the apron 22 in the load-carrying disposi- tion. More specifically, the cutting edge 34 may be abutted with the rear edge portion 35 of apron 22 to effectively close the bottom of the load-carrying space 33 and thereby effectively retain the scraped material 32 in the bowl 11 during the load-carrying operations.

In the scraping operation, blade 25 is piv¬ oted downwardly by the hydraulic cylinders 30 to bring the cutting edge 34 to the subjacent earth to be scraped. As shown in Figure 2, apron 22 is re- tained in the same position as in the load-carrying arrangement of Figure 1, and thus, continues to define the front wall and front portion of the bottom wall of the load space 33. As illustrated in Figure 2, the segmentally cylindrical configuration of blade 25 causes the scraped material 32 to move upwardly there-

along and roll forwardly onto.the apron 22 during the scraping operation. Thus, the transfer of material into the bowl is effectively unimpeded by the pre¬ viously collected material as it is deposited in the bowl forwardly of the blade. As shown in Figure 2, in the scraping position, arms 26 of the blade may engage the rear spreader bar 21 in one position.

When a full load of material is scraped into the bowl space 33, hydraulic cylinders 30 are extended so as to pivot blade 25 in a counterclockwise direc¬ tion about pivots 27 from the scraping position of Figure 2 to the load-carrying position of Figure 1 wherein the cutting edge 34 engages the rear portion 35 of apron 22. Thus, the blade and apron cooperate to define the front, rear and closed bottom walls of the bowl intermediate the fixed horizontally spaced sidewalls 16 and 17, permitting the load to be trans¬ ported as desired by the vehicle 10.

Referring now to Figure 3, to dump the col ^~ lected material 32 from the bowl, apron 22 is pivoted in a counterclockwise direction about pivots 24 by the hydraulic cylinder 29 to a retracted disposition wherein the apron extends to a considerable extent above the upper level of the sidewalls 16 and 17. In the retracted disposition, the rear portion 35 of apron 22 is removed from under the load space 33, per¬ mitting the collected material 32 to discharge down¬ wardly from space 33, as desired.

As further shown in Figure 3, during the dumping operation, blade 25 may be pivoted in a clock¬ wise direction by hydraulic cylinders 30 to a lowered disposition, further opening the bottom of the load space 33 and permitting the blade to be utilized in leveling the dumped material 32, as desired. In the illustrated embodiment, apron pivots

24 are disposed at the upper edge 37 of sidewalls 16 and 17.

Industrial Applicability

Thus, the scraper vehicle 10 provides an im- proved low cost earthworking apparatus wherein the scraper bowl 11 is defined by a pair of fixed, hori¬ zontally spaced sidewalls 16 and 17, a movable front apron 22, and a movable rear blade 25. Positioning means in the form of hydraulic cylinders 29 and 30 are associated with the apron and blade respectively to provide selective positioning thereof in a scraping arrangement, a load-carrying arrangement, and a dump¬ ing arrangement. The apron and blade illustratively are segmentally cylindrical so as to define a semi- cylindrical load space with the blade guiding the scraped material into a roll-over path depositing it on the rear portion of the apron and thereby effec¬ tively minimizing power requirements in the scraping operation. Scraper bowl structure 11 provides for auto¬ matic loading of the scraped material onto the apron by causing the material to clear itself from the blade in falling forwardly therefrom in a roll-over action onto the lower portion of the apron. Thus, the scraper bowl structure of the present invention is advantageously adapted for use in a wide range of scraper vehicles, such as used in earthmoving operations. By virtue of the reduced weight of the novel scraper bowl structure and the facilitated roll-over loading of the scraped material therein, the structure is adapted for use with trac¬ tive units of reduced horsepower and, thus, provides improved energy usage efficiency.

Further, as the scraper bowl effectively

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does not move upwardly or downwardly, but rather only the front and rear walls are repositioned in the dif¬ ferent arrangements of the structure, conventional draft arm and spreader structures are eliminated, thereby further reducing the structural weight and providing improved energy usage efficiency.

Still further, as the scraper bowl does not move up or down in use, there is no pitching motion of the tractor when the scraper loading mechanism is selectively lowered and raised. Thus, an improved match of the push-pull components on the tractor front portion and the scraper rear portion is provided.

The bowl structure utilizes the bowl spread¬ er element for improved support of the blade in the different selected dispositions thereof. Thus, as discussed above, the invention provides high strength in the bowl structure in use while yet effectively minimizes the number of structural elements and, thus, the overall weight of the apparatus, thereby providing further improved energy usage efficiency.

Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims. The foregoing disclosure of specific embodiments is il- lustrative of the broad inventive concepts compre¬ hended by the invention.