Road-Building Machinery

road, earth, rear, grader, wheels and scraping

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Buck scrapers are made in three sizes, the cutting edge being feet, 4 feet, and 5 feet; and their respective capacity is 8, 10, and 12 cubic feet.

Under favorable conditions this form of scraper will push con siderable earth along in front of it, and consequently the capacity is frequently stated as much greater than that given above. The cost is usually about $17, $18, and $19 respectively.

Wheel Scrapers.

The wheel scraper consists of a steel box mounted on wheels and furnished with levers for raising, lower ing, and dumping. All of the movements may be made without stopping the team. The wheel scraper is made in three sizes, No. 1, 2, and 3, having a capacity of 9, 12, and 16 cubic feet respect ively. Some manufacturers make an automatic front end-gate which adds materially to the load the scraper will carry, particu larly on a rough down-hill road.

Fig. 21, 22, and 23, page 101, show the three positions of the scraper. The forms shown have square-end boxes, but some manufacturers make a pressed round-end scoop. Some varieties have dirt-proof hubs, and there are also a variety of styles of wheels.

The cost of the three sizes at the factory is about $25, $30, and $40 respectively, varying somewhat with the details of construction.

Scraping Grader.

The machine shown in Fig. 24 and 25, page 102, is indifferently called a road machine or road grader, but it will here be called the scraping grader to distinguish it from the elevating grader (§ 149) and from other road machines. The scraping grader is a very important factor in caring for earth roads; and as an instrument of maintenance has been called a road hone, but could more properly be called a road plane.

There are several form of scraping graders of the type shown in Fig. 24 and 25, which differ in minor details but all of which accomplish substantially the same work. Each consists of a frame carried on four wheels, supporting an adjustable scraper blade, the front end of which plows a furrow while the rear end pushes the earth toward the center of the road or distributes it uniformly to form a smooth surface. The blade can be set at any

angle with the direction of draft, or at any height; and it may also be tilted forward or backward. This machine will work in almost any soil—even where a plow will not. It is hauled by horses, and makes successive rounds or cuts until the desired depth of ditch and crown of road is obtained.

Fig. 26 to 33, pages 104 to 108, show the various kinds of work that may be done with this type of machine.

Note in Fig. 28, page 105, that the front and rear wheels do not track. The whole rear end of the machine may be thrown to one side or the other by operating a hand-wheel. The object of this adjustment is to neutralize the lateral resistance of the earth to being pushed sidewise by the blade. In some forms of the scraping grader, substantially the same object is accomplished by shifting the rear axle lengthwise so that one rear wheel bears against the unplowed bank of the ditch (see Fig. 33, page 108); and in other forms the rear axle is telescoping, and either rear wheel can be moved in or out independently. Fig. 34, page 109, shows another method of neutralizing the lateral resistance of the earth. Either the front wheels or the rear one may be set at any inclination by operating a hand-wheel. The inclined wheel not only gives a com ponent to resist the lateral thrust of the earth, but also prevents the binding or cramping of the hub on the axle which occurs in ma chines having vertical wheels. The machine with inclined wheels has very recently been placed upon the market.

The preceding forms of scraping grader cost $225 to $250 at the factory. This machine is of inestimable value in constructing and maintaining earth roads, as it does the work better and much cheaper than it can be done either by hand or with plows and scrapers. The work done with the scraping grader is also superior to that done with plows and drag scrapers, since the plow cuts deeper in some places than others and these places are left full of loose earth and soon form holes which catch and hold water.

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