A&D Company, Ltd. (Head Office: Toshima Ward, Tokyo, Representative Director and President: Yasunobu Morishima) has acquired a patent for the AD-4976 series of metal detectors, that can detect metallic foreign matter in food and other materials with a high level of sensitivity by taking advantage of a variety of features, such as multi-frequency support.

With this invention, the resin plate below the belt of the belt conveyor can now be secured without the use of metal fittings, such as screws or snap locks.

Background that led to this Invention

A&D’s metal detectors are inspection machines mainly used in food factories. They are used to detect foreign metallic matter that may be contained in an item being tested while it is transported on a conveyor belt, and to inspect the safety of food and other products.

In these devices, a resin plate is placed under the conveyor belt to prevent the belt from bending so that objects to be inspected can be transported stably.

The plate is fixed to the main unit in way that takes into consideration ease of removal during maintenance. However, when metallic screws were used to secure the plates, the screws would gradually loosen in relation to the resin screw holes due to aging, causing the plates to rattle, and in some cases, the screws would fall off and be detected as foreign matter.

Therefore, in order to avoid this risk, snap locks that hook a metal arm onto metal fittings were used instead of screws. However, was also not a perfect countermeasure, as the spring strength would weaken due to aging.

In addition, it was fundamentally believed that placing any metallic material, such as a screw or a snap lock, near the detection section of the metal detector could negatively affect the detection sensitivity of the metal detector.

Purpose and Overview of the Invention

The purpose of this invention is to ensure that the resin plate can be reliably secured while being able to be easily removed without the use of metal materials, and to prevent to introduction of foreign metallic matter.

To achieve this purpose, a method to securely fix the resin plate without the use of metallic materials, such as screws or snap locks, was developed, so that our metal detectors can be used safely and without the worry of metal fittings falling off.

This fixing method allows for the easy installation and removal of the resin plates via a sliding operation, which improves maintainability, such as during the replacement of conveyor belts, which are indispensable for long-term use.

Main Features of AD-4976 Series Metal Detector

  • Multi-frequency support
  • Compatible with dry products, wet products, aluminum vapor deposition packages, and packages containing oxygen absorbents (optional)
  • Improved resistance to inverter noise
  • Improved vibration resistance
  • Noise disturbance visualization function
  • No need for warm up
  • Sensor head can be purchased separately
  • Easy operation due to the 7-inch color touch panel display
  • Washable and waterproof IP66 rated enclosure
  • Products can be inspected in 10 groups, with up to 100 products registered in each group
  • Images can be downloaded from a USB flash drive.

Patent Overview

Issue Date: March 13, 2020

Patent no.: Patent No. 6666059

Patent holder: A&D Company, Ltd.

Name of the invention: Metal detector

AD-4976 Product Page