726 Introduction to Machine Guarding

Pullback Devices

These devices consist of a system of cables or straps attached to the operator's hands, wrists, or arms. They are connected to the machine’s moving parts and are designed to automatically pull the operator’s hands away from the danger zone as the machine begins its operating cycle.

This type of safeguard is especially useful on machines where the operator must place their hands in or near the point of operation to feed or remove materials. The system works mechanically, so it does not rely on sensors or electronics.

Key Features of Pullback Devices

The key features for pullback devices include the following:

• Mechanical Linkage: Connected directly to the slide or ram, ensuring synchronized movement.
• Automatic Retraction: Pulls the operator’s hands back as the machine cycle starts, reducing the risk of injury.
• Hands-On Work: Allows operators to work directly with materials, yet still offers a level of safety during the hazardous portion of the cycle.
• Adjustment: The device must be adjusted to fit each individual operator correctly to function as intended.
• Maintenance and Testing: Pullback devices are only effective when properly maintained and tested regularly for wear or malfunction.
• Operator Training: Operators must be trained to understand how the system works and how to check for proper fit before use.

Examples:

• When the slide/ram is in the "up" position, the cables attached to the operator’s wrists are slack, allowing the operator to reach into the point of operation and feed materials into the die area.
• As the machine cycle begins and the slide/ram starts to descend, the cables tighten through a mechanical linkage and pull the operator's hands away from the danger zone, preventing accidental injury.

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