Abstract: A device for connecting bricks which have apertures to receive the device is provided. A support shaft of the device supports resilient transverse fins which form an interference fit with the aligned apertures of two adjacent bricks. Stop surfaces on the support shaft engage the respective bricks to ensure penetration of both bricks. Flared ends of the device facilitate insertion and centering of the device within the apertures and provide protection for the fins. During insertion, the transverse fins are deflected inward toward the support shaft and longitudinally toward the stop surfaces. After insertion, the fins are biased outward by their resiliency into engagement with the bricks to lock the adjacent bricks together.

Abstract: A system for supplying power to one or more electromagnets which includes a main power rectifier source and battery system including batteries charge controls and warning devices for one or more magnets such that in the event the main power source and/or the battery charger become inoperative power will be supplied to the magnets if energized at such time until the load on the magnet can be safely removed. Visual and/or audible indications are immediately given to the operator of the failure of either the main power rectifier or of the battery charger so that corrective and safety measures can be taken. A diode is provided between the battery and the load such that power flows from the battery only if the main power source voltage falls below that of the battery.