
Fresno Scraper
Origins
The Fresno scraper was invented in 1883 by James Porteous as a reaction to the need for a more efficient means of constructing canals and ditches in the sandy soil of California’s San Joaquin Valley
Born in 1848 in Haddington, Scotland, Porteous was the son of a wheelwright and blacksmith. In 1873, he immigrated to the United States, moving to Fresno and establishing a wagon shop. Originally named the Fresno Agricultural Works, it is now known as the Fresno Ag Hardware. It became the largest agricultural implement business in the valley and today is the oldest continuously operated business in Fresno.
Buckboards and Slip/Scoops were used throughout the San Joaquin Valley from the 1840s to the 1890s.
Working with the simple buckboard, Porteous made several design improvements and called it the Buck Scraper, which was patented in 1882.
Click on the blue headings below to see the changes that went into the creation of the Fresno Scraper.
A 5-foot Fresno was pulled by four good horses or mules, and used for leveling fields for irrigation as well as on dam and highway construction projects all over the world.
Allhands reported that a single Fresno had been known to move as much as 225 cubic yards of dirt in one long day.
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Pulled behind one or more horses, like a giant shovel. Once it was full of scraped dirt, it was skidded to the dump area where the operator lifted the handle to dump the load.
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In the middle of the 1800's the Buckboard was developed in the Western United States. It was a board which was drawn in an upright position to scrape and push the soil from a high spot into the low spots, smoothing and leveling the ground. The Buckboard had a tailboard upon which the driver stood until ready to dump the soil. Slip/Scoops and Buckboards were often used in combination. The Buckboard would smooth and level piles of earth dumped by the Slip/Scoops.
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Porteous’ first invention improved the Buckboard by fixing two main issues:
The tailboard, fixed in place, would lift up to dump the load,
Pushing soil took a lot of effort.
His solution was the Buck Scraper, patented in 1882. The tailboard was hinged, so when a lever was pulled back, soil moved onto the rear runners. Pushing the lever forward dumped the load, and the front runners set the soil’s grading depth. The drawbacks were that much soil fell off when the board was leveled, and the grading depth could not be changed.
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This second Porteous patent was an attempt to limit the scraper bowl rotation to dump the load to a controlled depth when the handle is pushed up. A cross bar could be adjusted forward or back on the bowl side plates to vary the limit position of the bowl as it strikes the tongue. The side runners or shoes raise the cutting edge above the ground.
There were three problems:
The high rolling resistance of the iron wheels in the soft or sandy soils,
The tendency of the scraper to overrun the horses on firm down slopes.
The short runners sinking into soft or sandy soils.
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William Deidrick of Selma, California, was awarded U.S. Patent 275, 893 issued April 17, 1883, (Figure 4), to overcome the problems of Porteous' second invention. Deidrick eliminated the wheels by utilizing long, flat, adjustable runners while retaining the bowl, handle and cross bar of Porteous' second patent. Whenever the cross bar position is changed, however, the runners need to be adjusted so that they run flat on the ground, otherwise they would drag on the front or rear tip ends.
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In this third patent, Porteous retained the general features of his second scraper, but substituted the cross bar with a more complicated means on the handle and tongue to adjust the thickness of the dump. Another approach to an adjustable means to vary the dump and use of curved runners was invented by Frank Dusy and Abijah McCall, also of Selma, California, U.S. Patent 320,055 issued June 16, 1885, (Figure 6).
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Frank Dusy and Abijah McCall used chains to control and adjust the dump by selecting the desired link to connect to hooks on each end of the draft axle. The circular arc runners to gauge the dump depth, while good in principle, were ineffective due to being so narrow as to slice through the soft, sandy soils.
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James Porteous bought the rights to the Deidrick patent by assignment dated January 31, 1889, and the Dusy and McCall patent assignment, dated February 7, 1896. Using some of the features of these patents along with his own ideas, Porteous perfected the scraper which became known as the "Fresno Scraper" (Figure 7), and commonly known as a "Fresno."
James Porteous