Security system including a revolving door

In a security system for controlling access to a protected region through an opening, of the type comprising:

• two opposite fixed walls of bullet-proof material, both in the form of partly cylindrical panels having a width such as to subtend an angle substantially in the region of 90.degree., said fixed walls being disposed on either side of said opening in such a way as to define between them a passage having an entrance opening facing outwardly of said protected region and an exit opening facing into said protected region,
• a revolving door turnable only in a single predetermined rotational sense about a vertical axis, said revolving door being located at the centre of said passage, said revolving door comprising four panels of bullet-proof material, angularly spaced from one another by 90.degree., and
• means for stopping the rotation of said revolving door with said door in a pre-established angular position and for locking it in this position whereby when said stopping and locking means are energised a person attempting to pass through said passage is trapped in a space between two adjacent panels of said revolving door and one of said two partly cylindrical walls,
• the improvement wherein:
• there are further provided auxiliary closure means, including a partly cylindrical panel of bullet-proof material, having a width at least as great as that of said exit opening, said panel of said auxiliary closure means being in the form of a sliding door angularly displaceable about said axis of rotation of said revolving door between an open position in which it does not obstruct said exit opening of said passage and a closure position in which it securely closes said exit opening,
• an upper support structure fixed to the upper ends of said fixed partly cylindrical walls;
• a curved track carried by said upper support structure, the length of said curved track being at least twice that of the width of said sliding door, said curved track being located so as to extend over said exit opening and part of one of said partly cylindrical fixed walls;
• suspension means including rollers for suspending said sliding door from said track,
• a curved guide element carried by said upper support structure,
• a closed loop of chain guided by said curved guide element,
• means attaching an intermediate point of said closed loop of chain to said sliding door, and
• a motor unit carried in said upper support structure for driving said closed loop of chain and consequently said sliding door.