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AGRICULTURAL MACHINES.

by Archibald Williams November 9th, 2023

Too Long; Didn't Read

THE THRESHING-MACHINE. Bread would not be so cheap as it is were the flail still the only means of separating the grain from the straw. What the cream separator has done for the dairy industry (p. 384), the threshing-machine has done for agriculture. A page or two ought therefore to be spared for this useful invention. [Pg 449] In Fig. 226 a very complete fore-and-aft section of the machine is given. After the bands of the sheaves have been cut, the latter are fed into the mouth of the drum a by the feeder, who stands in the feeding-box on the top of the machine. The drum revolves at a very high velocity, and is fitted with fluted beaters which act against a steel concave, or breastwork, b, the grain being threshed out of the straw in passing between the two. The breastwork is provided with open wires, through which most of the threshed grain, cavings (short straws), and chaff passes on to a sloping board. The straw is flung forward on to the shakers c, which gradually move the straw towards the open end and throw it off. Any grain, etc., that has escaped the drum falls through the shakers on to d, and works backwards to the caving riddles, or moving sieves, e. The main blower, by means of a revolving fan, n, sends air along the channel x upwards through these riddles, blowing the short straws away to the left. The grain, husks, and dust fall through e on to g, over the end of which they fall on to the chaff riddle, h. A second column of air from the blower drives the chaff away. The heavy grain, seeds, dust, etc., fall on to i, j, and k in turn, and are shaken until only the grain remains to pass along l to the elevator bottom, m. An endless band with cups attached to it scoops up the grain, carries it aloft, and shoots it into hopper p. It then goes through the shakers q, r, is dusted by the back end blower, s, and slides down t into the open end of the rotary screen-drum u, which is mounted on the slope, so that as it turns the grain travels gradually along it. The first half of the screen has wires set closely together. All the small grain that falls through this, called "thirds," passes into a hopper, and is collected in a sack attached to the hopper mouth. The "seconds" fall through the second half of the drum, more widely spaced, into their sack; and the "firsts" fall out of the end and through a third spout.

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AGRICULTURAL MACHINES.

THE THRESHING-MACHINE.

Bread would not be so cheap as it is were the flail still the only means of separating the grain from the straw. What the cream separator has done for the dairy industry (p. 384), the threshing-machine has done for agriculture. A page or two ought therefore to be spared for this useful invention.

In Fig. 226 a very complete fore-and-aft section of the machine is given. After the bands of the sheaves have been cut, the latter are fed into the mouth of the drum a by the feeder, who stands in the feeding-box on the top of the machine. The drum revolves at a very high velocity, and is fitted with fluted beaters which act against a steel concave, or breastwork, b, the grain being threshed out of the straw in passing between the two. The breastwork is provided with open wires, through which most of the threshed grain, cavings (short straws), and chaff passes on to a sloping board. The straw is flung forward on to the shakers c, which gradually move the straw towards the open end and throw it off. Any grain, etc., that has escaped the drum falls through the shakers on to d, and works backwards to the caving riddles, or moving sieves, e. The main blower, by means of a revolving fan, n, sends air along the channel x upwards through these riddles, blowing the short straws away to the left. The grain, husks, and dust fall through e on to g, over the end of which they fall on to the chaff riddle, h. A second column of air from the blower drives the chaff away. The heavy grain, seeds, dust, etc., fall on to i, j, and k in turn, and are shaken until only the grain remains to pass along l to the elevator bottom, m. An endless band with cups attached to it scoops up the grain, carries it aloft, and shoots it into hopper p. It then goes through the shakers q, r, is dusted by the back end blower, s, and slides down t into the open end of the rotary screen-drum u, which is mounted on the slope, so that as it turns the grain travels gradually along it. The first half of the screen has wires set closely together. All the small grain that falls through this, called "thirds," passes into a hopper, and is collected in a sack attached to the hopper mouth. The "seconds" fall through the second half of the drum, more widely spaced, into their sack; and the "firsts" fall out of the end and through a third spout.

MOWING-MACHINES.

The ordinary lawn—mower employs a revolving reel, built up of spirally-arranged knives, the edges of which pass very close to a sharp plate projecting from the frame of the mower. Each blade, as it turns, works along the plate, giving a shearing cut to any grass that may be caught between the two cutting edges. The action is that of a pair of scissors (Fig. 227), one blade representing the fixed, the other the moving knife. If you place a cylinder of wood in the scissors it will be driven forward by the closing of the blades, and be marked by them as it passes along the edges. The same thing happens with grass, which is so soft that it is cut right through.

HAY-CUTTER.

The hay-cutter is another adaptation of the same principle. A cutter-bar is pulled rapidly backwards and forwards in a frame which runs a few inches above the ground by a crank driven by the wheels through gearing. To the front edge of the bar are attached by one side a number of triangular knives. The frame carries an equal number of spikes pointing forward horizontally. Through slots in these the cutter-bar works, and its knives give a drawing cut to grass caught between them and the sides of the spikes.

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This book is part of the public domain. Archibald Williams (2009). How it Works. Urbana, Illinois: Project Gutenberg. Retrieved https://www.gutenberg.org/cache/epub/28553/pg28553-images.html

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