Abstract: A nutating pump of the type which has a rotatable shaft with a central member with an annular support groove at an angle to the shaft in which a disk is moveably supported and is restrained against rotation by a partition inserted in a radial slot in the disk, and has conial sections coaxial with the shaft and positioned on either side of the central member, the peripheral surface of the conic sections and the annular groove being at substantially the same angle with respect to the shaft. One such pump includes moveably replaceable central members and conic sections whereby the operating characteristics of the pump may be changed without having to replace the pump body. In another embodiment, a cylindrical insert is included in the radial slot in the disc, and grooves are included in the peripheral surfaces of the conic sections to receive the cylindrical insert as it passes over the surfaces of the conic section.

Abstract: Apparatus for determining the dynamic complex hardness of resilient roll coverings including a portable housing for positioning directly on the resilient roll covering to be tested. The portable housing includes an adjustable probe coupled to force and displacement transducers. The adjustable probe is placed in contact with the resilient roll covering and vibrated. The transducers produce output signals in accordance with the force encountered by and displacement of the probe during displacement of the surface of the resilient roll covering. The output signals from the transducers are coupled to dynamic hardness and loss angle circuitry for providing direct measurements of the magnitude and phase angle of the dynamic complex hardness.