Scaled Management Systems

Interlocked transparent door improves guard

Interlocked transparent door improves guard


A tapware manufacturing company was using a conventionally guarded hydraulic press for stamping brass components. Four dies were arranged on a circular table. After each pressing table had rotated clockwise (indexed) one position the next die was positioned under the press.

The conventional guard protected against entrapment between the press and die, but it was possible for entrapment to occur between the die and the steel guard when the table rotated.


The guard was modified to include a hinged transparent acrylic door which was connected by an interlock switch to the press and table. If the hinged acrylic door was opened the machine would stop and remain stationary until reset.

The bottom edge of the acrylic door was contoured to closely match the shape of the die and components passing beneath it.

Hierarchy of Controls:



  • The jaws of the press were correctly regarded as the principal safety hazard, but in this case the press had intermittently moving parts which protruded beyond the normal guard.
  • An imaginative improvement was accomplished at minimal cost.