Text 9. Potato harvesting equipment

Potato diggers can be divided into two main types, the elevator digger and the spinner.

Elevator diggers may lift one or two rows at a time. They consist of broad A-shaped shares which lift the drill. The contents of the drill are raised by the forward motion and deposited on an endless rod link elevator or web. The soil fells through the links and the potatoes pass off the end of the elevator to the ground. To separate the maximum soil and trash from the potatoes, various means of controlling the degree of agitation on the web are used.

1. Oval sprockets of various sizes can be fitted under the web, between the two end sprockets, to increase agitation.

2. The elevator can be split and run in two sections, the potatoes and soil falling from the first to the second position.

3. The angle of the elevator can be altered, thus varying the speed at which the potatoes and soil pass over the web, hence the agitation they receive.

4. The drive to the elevator is by land wheel via a gearbox or by tractor p.t.o. With both, the elevator to forward speed ratio can be varied.

Tractor wheels settings must fit the row width. The depth of the share is generally controlled by two screw adjust able wheels. The share should be set as shallow as possible, to reduce the amount of soil lift and, hence, the agitation necessary.

Spinners have the advantage over elevator diggers, in that they are capable of working under quite wet soil conditions. They are liable, however, to cause more damage to the crop, due to the method of lifting and separating.

spinner - роторная швырялка

link elevator or web - вытряхивающий транспортер

Text 10. Sugar beet harvesters

The problem of harvesting sugar beet is simpler than that of harvesting potatoes. The beet is more tolerant of mechanical damage. Also, beet grows in very straight lines, with similar root and crown shape. It is harvested in two operations: topping and then lifting.

Topping mechanisms. A series of discs known as the feeler wheel, driven by the axle of the harvester at a speed slightly greater than if it were rolling over the ground, pierces through the tops into the crown of the beet. The tops can be collected by a top saver and placed in a windrow or left scattered on the ground.

Lifting mechanism. The commonest type of lifting mechanism is a pair оf V-shaped shares, inclined slightly into the ground and depth — controlled by a screw — adjusted wheel.

The next mechanisms are designed to remove soil from the beet and carry the beet to a tan on the machine or a trailer being drawn alongside. The cleaning devices may consist of elevators with oval agitators or an elevator rolling the beet against a fixed web.

Another lifting mechanism consists of two large wheels, inclined towards each other. They rotate due to contact with the ground and lift the beet out of the ground.

Tractor wheel settings must suit the row width. The centre of the topping unit should be exactly one row width from the centre of the lifting unit. The lifting share⁴⁾ should run as shallow as possible, yet still harvest all the beet. If the soil is hard or stony, the pitch of the shares can be increased a little, to help penetration. The degree of agitation on the elevators depends upon the type and condition of the soil also on. Whether the beet is going to be cleaned again before being transported to the factory.

topping mechanism - обрезающий механизм

feeler wheel - копирующее колесо

top saver - ботвоуловитель

lifting share - подкапывающая лапа