A pulverizer for crushing coal for use in a combustion process includes a bowl shaped body, a roller dimensioned and configured for contact with at least a portion of the bowl shaped body, apparatus for causing relative movement between the bowl shaped body and the roller; and apparatus for biasing the roller against the bowl shaped body, the apparatus for biasing including a spring assemblyat includes a first spring and a second spring. The apparatus means for biasing including apparatus allowing initial compression of the first spring before the second spring is compressed. In some forms of the invention the first spring and the second spring are coil springs and the first and second springs are compressed simultaneously after initial compression of the first spring. In other forms of the invention the first and second springs are disposed in coaxial relationship with the second spring overlapping an axial part of the first spring. In this form of the invention the second spring has a free axial length that is less than the free axial length of the first spring. The apparatus allowing initial compression may include a washer disposed at one axial extremity of the first spring and a spring seat disposed at a second axial extremity of the first spring. The apparatus may include a shaft extending between the spring retainer and the washer, the shaft may include apparatus for preloading the first spring without preloading the second spring. The first spring and the second spring may be disposed in substantially coaxial substantially end abutting relationship and the apparatus may include a floating plate disposed intermediate the first and second springs. A generally sleeve shaped member may surround at least an axial portion of the first spring and the first spring may have a lower spring constant than the second spring. The generally sleeve shape member may extend around a portion of the axial extent of the first spring and the sleeve shape member may be dimensioned and configured for engagement with the floating plate after initial compression of the first spring whereby after contact of the sleeve shape member with the floating plate the first spring will not compress axially any further. In some forms of the invention the apparatus includes apparatus for compressing the first and second springs simultaneously whereby both the first and second springs are preloaded.