Doormats with 1/2 in finger-like projections were glued and bolted to the upper roll

Выражение встречается в следующем контексте:

This feeding arrangement:
• Headed the tops ot the alfalfa plant into and between
the rolls
• Untanglcd lodged and tangled plants
• Positioned plants parallel to the direction ol travel so
their machine entry would be perpendicular to the axis of the stripping rolls
The stripping mechanism was a heavy rubber doormat. Doormats with 1/2 in finger-like projections were glued and bolted to the upper roll.
Заранее спасибо