US 4,723,118 A · Magnetic detection system for items on the lower tray of a shopping cart

Abstract

A detection system for use by a checkout clerk in a checkout line to detect a load left on the lower tray of a shopping cart by the customer. The shopping cart has a lower tray pivotably mounted on a frame. The tray is movable between a first and second position when a load is placed on the tray. A field producing source such as a permanent magnet contained within a shield material is attached to the cart, and the field is actuated at a distance when the tray is moved from the first to the second position by displacing the magnet and the shield material. A detector for detecting the presence of that field as the shopping cart passes through the checkout line is coupled to a control circuit capable of signaling the checkout clerk that the load is on the lower tray.

Claims11

Dependent claims

On a shopping cart having a frame and a tray, said tray being movable between a first position and a second position when a load is placed on said tray, the improvement being a detector system comprising:

a field producing source carried on the cart and generating a field detectable at a predetermined distance;
actuation means on the cart for selectively actuating said field at said distance responsive to movement of the tray from the first to the second position;
detection means for detecting said field at said distance;
and
signaling means for signaling the detection of said field by said detection means.

2 more elements

On a shopping cart having a frame and a tray, said tray being movable between a first position and second position when a load is placed on said tray, the improvement being a detector system comprising:

a field producing source carried on the cart and generating a field detectable within a range of distances;
actuation means on the cart for selectively actuating said field within said range of distances responsive to movement of the tray from the first to the second position;
detection means for detecting said field within said range of distances;
and
signaling means for signaling the detection of said field by said detection means.

2 more elements

Dependencies are inferred from the claim text.

Magnetic detection system for items on the lower tray of a shopping cart

Life of this patent

Magnetic detection system for items on the lower tray of a shopping cart

Life of this patent

Abstract

Claims11