The length of the tow arms and the location of the tow points determine the amount of self-adjusting. A longer wheel base and longer tow arms increase the averaging of the high spots and the low spots. This will give a smoother road surface.
The self-adjusting of the screed depends on the distance instead of the mechanical ratio. When you adjust the screed, the reaction time is five lengths of the tow arm. The machine may roll over a bump before the screed will noticeably react. The screed will continue to leave a level surface.
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| Illustration 1 | g00873424 |
The amount of self-adjusting is improved by the oscillating bogies on the front of the wheel type asphalt paver. The amount of self-adjusting is improved by the oscillating bogies on the track-type asphalt pavers.
Change the level gradually over a longer distance in order to prevent waves in the surface. The importance of this characteristic is seen as a smooth surface when the base is uneven.
When the paver encounters a depression, the reverse action takes place. As the machine travels downward, the screed is automatically tilted down. The screed will continue to travel downward until the screed is parallel to the horizontal plane of the machine.