Safety mechanism for control of hydraulic pump - includes interlocking catch requiring simultaneous operation of two hand levers

摘要

The control for a roller press includes a pivoting lever linked via a cable (4) to a right angle lever (5) pivoting about a point (6). This is connected to the lower arm of a second pivoting lever (9) whose upper arm is connected to a rod operating the pump. Movement of the second lever moves a support (11) with a cam surface uppermost. The cam surface has a central notch into which a hooked latch (15) may fall. In order to be able to operate the pump control the latch must be raised away from the cam to free it. A second control lever comprising a hand ring (1) is attached via a cable (18) and spring mechanism (19) to move the position of the latch. The second lever must be lifted to enable the spring (19) to lift the latch from the cam surface. The pump may not be operated by using the first lever alone. The safety mechanism may be used to control a pump operating a hydraulic roller press to avoid accidental operation.