Theft prevention apparatus for shopping carts

Claim 1

Theft-prevention apparatus for a shopping cart of the type having body means, a plurality of wheels and wheel support means secured to said body means for rotatably supporting said plurality of wheels, said apparatus comprising: a. stopper means secured to one of said wheels; b. engagement means movable between a first inoperative position and a second operative position at which said engagement means is engageable with said stopper means, said engagement means including ball means movable between said first inoperative position and said second operative position at which said ball means is engageable with said stopper means; and c. actuator means secured to said wheel support means for controlling movement of said engagement means from said first inoperative position to said second operative position for engagement with said stopper means in response to movement of said shopping cart in the proximity of a predetermined magnetic field to prevent rotation of said one of said wheels, said actuator means including plate means secured to said wheel support means and having a cut-out section defining an aperture, ball support means for supporting said ball means at said first inoperative position, and solenoid means secured to said plate means for moving said ball support means to a position adjacent said aperture in response to movement of said shopping cart in the proximity of said predetermined magnetic field to cause said ball means to move from said first inoperative position through said aperture to said second operative position, such that said ball means is wedged between said plate means and said stopper means upon continued rotation of said one of said wheels to prevent further rotation thereof.