Carl A. Reaves

Influence of width and depth of cut on disk forces.

ABSTRACT WIDTH and depth of disk cuts are variables which can be used to influence the nature of forces on disks. The sizes of cut were varied in wide ranges for nine test disks operating at a disk angle of 0.38 rad and a for-ward velocity of 1.3 m/s. The specific draft of the dif-ferent disks varied less than the draft as a function of depth of operation. Forces were generally highest for the spherical disks with the lowest radius of curvature. The forces on conical disks used in the studies were generally between those of the two spherical disks.

The Influence of Harrow Disk Curvature on Forces

ABSTRACT A series of seven 610-mm-diameter disks having radii of curvature varying from infinite (flat disk) to 494 mm were tested for draft, vertical, and side forces. At disk angles between 0.2 and 0.3 rad, the smaller the cur-vature of the disk, the larger the soil force on the back surface of the disk. Because of the magnitude and direc-tion of the side force, optimum disk shapes, both in terms of forces and soil handling, may lie in the in-termediate range of radii of curvature-to-disk diameter (1.33 to 2.92) rather than at the extremes studied.

The Effect of Geometric Parameters on Disk Forces

ABSTRACT STUDIES of forces on large harrow disks show that harrow design conditions are influenced by disk blade geometry. Increases in draft caused by increases in velocity are essentially linear. Because of pressure on the blades of disks, an optimum angle in terms of draft oc-curs for operations of disks.

Harrow Disk Curvature — Influence on Soil Penetration

ABSTRACT A series of seven 610-mm-diameter disks was con-structed with radii of curvature varying from infinite (flat disk) to 494 mm. The soil penetration of these disks depended on velocity, mass on the disk, and disk angle. At disk angles from 0.2 to 0.35 rad, disks with large radii of curvature penetrated deeper. At disk angles above 0.35 rad, small radii of curvature disks penetrated deep-er. In terms of disk penetration, the optimum value of radius of curvature-to-disk-diameter (R/D) ratio ap-pears to be 2.92 to 1.50.

The Influence of Velocity and Disk Angle on the Kinematic Parameter A of Disks

ABSTRACT THE kinematic parameter A, the ratio of rotational velocity to forward velocity, of experimental disks was studied as a function of change of disk angle and disk velocity. Disks with reduced back pressures rotated more rapidly than the conventional spherical disk. The absolute velocity of a point on the edge of a rotating disk has a cosinal nature, the minimum velocity of which is at the lowest underground point of the disk.