Figure 18.1 Five types of brake and clutch. (a) internal, expanding rim type; (b) external contracting rim type; (c) band brake; (d) thrust disk; (e) cone disk. . Brake and Clutch Types. Figure 18.2 Thrust disk clutch surface with various radii. . Figure 18.3 Effect of radius ratio on dimensionless torque for uniform pressure and uniform wear models. .