In order to fully prevent accidents causing injuries for the machine operators, it is necessary to design their gaps so that no part of the human body can enter between the equipment. ISO 13854/JIS B9711 defines the standards.

(1) Minimum gaps to avoid crushing of parts of the human body

Crushing accidents of the human body by operating mechanical devices are known to occur in the following two mechanisms:

a) Two moving parts travel toward each other
b) One moving part travels toward the fixed unit

The figure shown here defines the "minimum gaps" of the equipment to avoid crushing accidents. It is recommended to adopt these measurements into the mechanical design.

Remarks

1) These "minimum gaps" defined are effective for avoiding crushing only and not effective for preventing other hazards (including shocks, drawing-in, shearing hazards).
2) In some cases, characteristics of persons involved must be considered.

Examples:
Body size differences based on the ethnicity under the global environment,
Possibilities of endangering children, etc.

[Fig.] Minimum gaps to avoid crushing accidents of human body (unit: mm) (Source: ISO 13854/JIS B9711)

Body parts Minimum gap a Illustration Body 500 Head (the worst position) 300 Leg 180 Foot 120 Toe 50 Arm 120 Hand, wrist, fist 100 Finger 25