In the previous volume, we learned the concept of intrinsic safety for machinery. In this lecture, we will learn what the intrinsic safety is all about from the examples of the press machine and swaging equipment structures.

(1) What is the intrinsic safety of machinery

The codes on the intrinsic safety of machinery include the following three measures:

1) The safety design has been built into or embedded in the machinery.

2) The machinery has a foolproof feature that prevents accidents or disasters even in case of an incorrect operation of the machine equipment.

3) The machinery has a fail-safe feature that the equipment responds in a safe manner even in case of malfunctions or damages of the machine equipment and parts.

(2) Intrinsic safety for press machines and swaging equipment

- Most of the accidents associated with press machines or swaging equipment occur during the following processes: 1) Material supply tasks, 2) Tasks involving touching processing points, in order to adjust or correct the material position, for example.

- The intrinsic safety must be considered in designing these machines since many people injured in such situations are likely to suffer from the aftereffects.

- If it is not possible to incorporate the intrinsic safety design, the safety device must be installed.

- Examples of intrinsic safety design

a) Installation of a safety enclosure for the press die --- Install an enclosure around the die so that the operator's hands or fingers will not contact the processing points.

b) Adopting a structurally safe design --- Keep the clearance between the upper and lower dies or between strippers for the upper and lower dies to be 8 mm or less to prevent the operator's hands or fingers from being placed in the gap. (See [Fig.1])

c) Automatic press design --- Eliminate tasks requiring hand insertion by adopting an automatic system of supplying materials and/or discharging processed goods.

d) Safety press design --- Install a safety device with optical sensor or embed the safety design into the equipment by installing a two-hand control button.