Press brake
 A brake press including a stationary bar, a translating bar, a disk rotatable about a fixed, stationary axis, a first set of linkage interconnecting one longitudinal end of the translating bar with the disk, and a second set of linkage interconnecting the other longitudinal end of the translating bar with the disk. The rotation of the disk in a first direction acts through both sets of linkage to translate the translating bar toward the stationary bar, and the rotation of the disk in a second direction acts through both sets of linkage to translate the translating bar away from the stationary bar. The disk may be selectively rotated in either direction or maintained in a stationary position by one or more hydraulic rams. The flow of hydraulic fluid to the hydraulic rams is controlled by a foot pedal which is biased in a position which will cause the hydraulic rams to rotate the disk so that the translating bar is moved away from the stationary bar. 
B B
B30B B21D
inventional inventional
James B.
Hill