Abstract: Coin-controlled apparatus for locking shopping carts together in nested series at a cart parking station having coin-controlled mechanism mounted on a cart, e.g. on the handle of the cart, which is adapted for receiving and releasably locking therein a latch bar on a tether which is attached to the next cart in the nested series. Deposit of a coin is required to release the latch bar to free the cart for being wheeled away by the user. The coin is held until the user brings the cart back to a cart parking station, nests it in the end cart at the parking station, and inserts the latch bar which is tethered to the end cart in the mechanism to lock the returned cart to the series and to provide for return of the user's coin. The apparatus has a detent arrangement permitting reduction in its size.

Abstract: A shopping cart security system assists in preventing the theft of a shopping cart from a parking lot of an establishment where the carts are used. The parking lot has at least one entrance and exit driveway. The system includes a magnet mounted on the shopping cart and an actuator buried below the surface of the driveway for generating a signal in response to passage of the cart with the magnet over the driveway. The actuator extends generally transversely with respect to and substantially completely across the driveway. An alarm issues a warning in response to the signal generated by the actuator. Also, a system for monitoring unauthorized entry into a restricted area having a door, a magnet carried by the door and an actuator controlled by the magnet for signalling opening of the door.