Press Brakes Providing the Best Operator Protection
When the ram is travelling down* at maximum speed, the ability of the machine’s ram stopping mechanism is drastically reduced as compared to the stopping time during the slow speed forming portion of the stroke.
Most press brake injuries occur when the operator gets their fingers or hand trapped between the dies during the fast downward motion of the ram. The tragic and most ironic thing is . . . the operator, once trapped, in shock and experiencing extreme pain . . .reacts by making the machine continue through the stroke in what they believe is the only way to escape. Often this causes amputation by crushing, resulting in bone and tissue trauma that is medically not repairable.
Consider this. If the fast downward motion of the ram could be guarded by light curtains until the upper die is just 1/4 inch from the top of the material . . .the ram forced to stop . . .the light curtains muted (ignored) and the operator required to consciously re-initiate the downward motion of the ram at slow speed. . . then the part could be formed safely and without accidents like the one in the above example.
Unfortunately, not many part shapes can be formed using the above example. The REAL world is not so flexible. But if there could be MUTE points higher than 1/4 inch, so that parts could be inserted into the die area after the ram reaches the MUTE point, then any configuration could be formed. Take it one step further; if the ram could be controlled to stop at programmed MUTE points on a given sequence of strokes, then the operator could form complex shapes in the same manner as he/she would use a back gauge!
The only difference in the above operation is that the operator inserts the part into the die when the ram reaches the MUTE point instead of when the ram is at the top of the stroke. There is no lost production time!
*”Up” for up-acting presses