Abstract: A security bar assembly has a plurality of bars that extend across an opening and have ends joined to drive chains. The bars may extend between two channels positioned on opposite faces of the opening, and may be slidable within the channels. The ends of the bars may be retained in the channels and the ends may have connections to chain links in opposing drive chains which are spaced apart a predetermined number of links to keep the bars a predetermined distance apart. A drive mechanism may be provided for moving the drive chains to slide the bars in the channels and a storage area adjacent the opening associated with the channels to retain the bars when they are not in place over the opening. Transfer mechanisms are provided for moving the security bars between a stored position and a position in which the bars engage the bar drive chain.

Abstract: In one aspect, the invention provides an endless loop lock including a drive wheel adapted to be driven or not driven. An endless loop may be provided, engaging the drive wheel and adapted to be driven by the drive wheel to move a device, such as a security bar, connected to the endless loop. A guide may be provided, biased against the endless loop at a position spaced apart from the drive wheel. A lock may be provided, for engaging the endless loop to inhibit movement of the endless loop, the guide being positioned to bias the endless loop out of engagement with the lock when the endless loop is driven by the drive wheel. The lock may be actuated by a force applied to the device connected to the endless loop when the drive wheel is not driven.

Abstract: A security bar assembly has a plurality of bars that extend across an opening and have ends joined to drive chains. The bars may extend between two channels positioned on opposite faces of the opening, and may be slidable within the channels. The ends of the bars may be retained in the channels and the ends may have connections to chain links in opposing drive chains which are spaced apart a predetermined number of links to keep the bars a predetermined distance apart. A drive mechanism may be provided for moving the drive chains to slide the bars in the channels and a storage area adjacent the opening associated with the channels to retain the bars when they are not in place over the opening. Transfer mechanisms are provided for moving the security bars between a stored position and a position in which the bars engage the bar drive chain.

Abstract: A security bar assembly has a plurality of bars that extend across an opening and have ends joined to drive chains. The bars may extend between two channels positioned on opposite faces of the opening, and may be slidable within the channels. The ends of the bars may be retained in the channels and the ends may have connections to chain links in opposing drive chains which are spaced apart a predetermined number of links to keep the bars a predetermined distance apart. A drive mechanism may be provided for moving the drive chains to slide the bars in the channels and a storage area adjacent the opening associated with the channels to retain the bars when they are not in place over the opening. Transfer mechanisms are provided for moving the security bars between a stored position and a position in which the bars engage the bar drive chain.

Abstract: In one aspect, the invention provides an endless loop lock including a drive wheel adapted to be driven or not driven. An endless loop may be provided, engaging the drive wheel and adapted to be driven by the drive wheel to move a device, such as a security bar, connected to the endless loop. A guide may be provided, biased against the endless loop at a position spaced apart from the drive wheel. A lock may be provided, for engaging the endless loop to inhibit movement of the endless loop, the guide being positioned to bias the endless loop out of engagement with the lock when the endless loop is driven by the drive wheel. The lock may be actuated by a force applied to the device connected to the endless loop when the drive wheel is not driven.