Assertion: pulley | /r/HasProperty | convex to keep the flat belt
Facets:
value: without a groove
type: OTHER
value: without flanges
type: OTHER
value: often
type: TEMPORAL
value: slightly
type: DEGREE
Source sentences:
text: In the case of a drum-style pulley, without a groove or flanges, the pulley often is slightly convex to keep the flat belt centered.