Lightening THE LOAD: MECHANIZED LOADER EASED BACK-BREAKING FARM LABOR.
John Deere introduced an unusual loader in 1939-40. It was mounted at the rear of the tractor and had a turntable and mast attached to the drawbar with diagonal braces to the rear axles (see images 1 and 2, opposite page). A 12-foot boom that could be raised and lowered swung in a 180-degree arc, and a forked bucket traveled along the underside of the boom to pick up the manure. When the loader was in position to begin operation, a large shoe-type pedestal was dropped down and locked in place to support most of the weight of the loader.
The loader's cable-controlled operations were driven by the tractor's PTO through roller chain drives to the clutch and winch units. Moving the left lever forward advanced the loader bucket to fill it, and pulling the lever back retracted the bucket. The right lever controlled the boom; moving it forward raised it and backward lowered it.
When the levers were released, they automatically returned to the neutral (or center) position, stopping further movement of the bucket and boom. The bucket was dumped by extending it to the end of the boom. At that point, the bucket teeth were 6-1/2 feet above the ground and 8 feet out from the mast when the boom was at its maximum height. The swing of the boom was controlled by foot pedals: Pushing the left pedal swung the boom to the operator's right and vice versa with the right pedal.
After the loader had cleaned the area that it could reach (a half circle with a 10-foot radius), the tractor was backed up to a new working position by simply unlocking the pedestal brake and letting the shoe slide over the cleaned area. Obviously the tractor could not be moved while it was loading manure.
Cattle sheds could be cleaned with the loader if the opening was at least 8 feet high (to clear the mast) and wide enough for the loader and a spreader to be placed side by side. In those tight quarters, the operator had to be careful to depress the correct foot pedal, or he might put the boom out through the side of the shed.
One major limitation
The loader could be mounted on John Deere Model B, A or G tractors, but a special front-mounted weight box was provided for the B and the A to counterbalance the loader bucket.
To prepare the unit for transport, the pedestal was raised manually and locked into place, and a pin was installed in the turntable to ensure it did not rotate. Since the loader's weight was on the tractor's rear axle, it provided extra traction when encountering adverse ground conditions, as opposed to a front loader that removed weight from the rear wheels.
By 1946, a dirt bucket was also available for use on the loader for handling dirt, gravel or similar materials on the farm. It was smaller than the manure bucket and had shorter teeth. The maximum load with either bucket was "around 850 pounds."
Although this rear-mounted loader claimed to load as much manure as five men could, it had one significant limitation: The tractor could not be moved with a load in the bucket, or in other words, it could not perform a "load and carry" operation.
Introduction of the push-type loader
To address that disadvantage, John Deere introduced the Model 25 "push-type" loader in 1947, which mounted on the front of the Model A or B tractors. With this loader, the same tractor could be used to load the spreader and then it could be hitched to the spreader to spread the manure.
The loader's parallel arms kept the load level throughout the lift cycle. It used cables and a winch to raise and lower the lift arms and a trip rope to dump the bucket at any height. A pulley attached directly to the tractor's flywheel powered the winch through a foot-operated clutch, which supplied "live power" anytime the engine was running. A cross shaft provided cable drums on both sides of the tractor, and the complete drive mechanism was located just in front of the left rear axle to add weight to the rear wheels and improve traction. To protect the loader if the bucket got caught under an unmovable or an extremely heavy object, an overload release set at 1,500 pounds was built into the clutch.
Five settings were available to adjust the angle or "suck" of the bucket, and the power dump could be used to shake the bucket to completely empty it. The entrance of the loader into a shed was not limited because the loader frame was no higher than the tractor's exhaust stack. A standard equipment solid-bottom plate could be attached to the tines so the bucket could handle dirt and other loose material.
Two attachments were available for the Model 25 loader: a 60-inch wide snow shovel that fit onto the manure fork, and a bulldozer blade that could be angled from the tractor seat to nine positions in a 60-degree arc. The loader could be used for many jobs around the farm, such as pulling fence posts, moving small individual hog houses, filling ditches and any other job the farmer could imagine.
Hydraulics with unique features
John Deere's first hydraulic manure loader was the Model 30. It mounted on the little Model M tractor that went into production in 1947 and was later replaced by the Model 40 tractor. The loader used box-framed lift arms that had to curve over the M's wide front axle.
A "live" hydraulic system provided loader operation any time the tractor engine was running, and the system had two unique features. First, while most hydraulic loaders at that time had single-acting cylinders with pressure applied at the head end of the cylinder to raise the lift arms and then depended on gravity to lower them, the Model 30 loader had double-acting cylinders that powered the lift arms up and down, resulting in faster cycle times. That allowed oil to be transferred from one end of the cylinders to the other when raising and lowering the bucket. The second unique feature on the John Deere Model 30 loader raised the lift arms by pressurizing the rod end of the cylinders, thereby pulling the arms up rather than pushing them.
The 35-inch-wide bucket with tapered spring-steel teeth and sharp side cutting edges allowed the bucket to be filled with a minimum amount of push from the tractor. Two hand wheels, one on each side, adjusted the angle or "suck" of the bucket when loading. As the lift arms were raised, the bucket initially remained level and then tilted backward to retain the load in the upper part of the cycle until reaching the maximum dump height of 9-1/2 feet. The bucket was dumped by manually pulling a lever, and a hydraulic relief valve provided overload protection.
The Model 30 loader came equipped with a front bumper, a solid plate for installation under the bucket teeth for loading loose material and a sling to use when attaching or removing the loader to or from the tractor. There were only six places where the loader attached to the Model M, and the sling was designed to connect to an overhead hoist, if one was available. Rear wheel weights were also recommended to improve traction of the rear tires. Optional equipment for the Model 30 was the same as for the Model 25--a bulldozer blade and snow bucket--but a dirt bucket that had the bottom plate with additional sides was also available.
While the John Deere manure spreader had preceded the company's loader by at least 40 years, the loader finally made a significant contribution to reducing manual labor on the farm.
By Jim Cay
Jim Gay was raised on an Iowa farm and received a degree in Agricultural Engineering at Iowa State University. He is a lifelong collector of farm and construction equipment literature and information. Email him at firstname.lastname@example.org.
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|Date:||Jan 1, 2019|
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