Abstract: A security transfer unit includes a hollow box-structure that has open ends on opposite sides of a security barrier and is supported from side-frames with a clearance underneath. A rolling shutter encircles the box-structure to block access to either end to the chamber through openings in the unit casing. The shutter is driven to bring an aperture therein into register with the openings in turn so that access to the chamber can be gained through only one of them at a time. Drive is in one direction only and is interrupted with the shutter blocking both openings when the aperture is located in register with an aperture in the box-structure, so as to enable viewing of the contents of the transfer chamber through a window above.

Abstract: A security transfer unit has a cashier's door and a customer's door for providing access to an intermediate transfer chamber from opposite sides of a security screen. Only one of the doors can be opened to give access to the chamber at a time, opening of the cashier's door being normally obstructed by a pivotted bar that is swung down across the door to engage a bracket. Swinging of the bar up to remove the obstruction turns a shaft to block, via a cam, withdrawal of catch-bolts which hold the customer's door closed. The cam in this condition also abuts a block mounted on the rear edge of the door such that if the customer's door is open as the bar is swung up it will be forced closed before the cashier's door can be opened.