US 4,726,434 A · Metal detector testing process and apparatus in a combination weighing system

Abstract

An apparatus for testing a metal detector is incorporated in a combination weighing system where the metal detector is located to monitor product as it passes through a discharge chute of the combination weighing machine into a package. The apparatus includes a computer programmable by an operator to initiate a metal detector test operation. Upon such initiation, the computer holds out a first one of the scales from one or more subsequent combination searches while a metal test object is deposited in a first scale. Then the computer performs a combination search of the scales to select a test combination which includes the first scale and other scales as needed to achieve the target weight, discharges the selected combination and monitors the output of the metal detector or determine if it is working. Related methods are also disclosed. A feed mechanism is optionally provided to automatically deposit a test object in the first scale in which case, the computer is programmed to periodically activate the feed mechanism and initiate a metal detector test operation.

Claims19

Dependent claims

A process for testing a metal detector positioned to monitor product as the product passes through a common discharge chute of a cyclically operated combination weighing system, said weighing system comprising a plurality of weighing scales feeding said common discharge chute, said process comprising the steps of:

depositing a metal test object in a first one of said weighing scales,
searching said plurality of weighing scales while said first weighing scale contains said metal test object for a first selected combination of scales which includes said first scale and contains a combined quantity of product near a target weight,
discharging the product and the metal test object from said first selected combination of scales into said common discharge chute, positioning a metal detector in the vicinity of the outlet of the discharge chute to detect metal in the product discharged by the first selected combination of scales;
and
monitoring said metal detector to determine whether it detects said metal test object discharged through said common discharge chute from said first weighing scale.

2 more elements

A process for testing a metal detector positioned to monitor product as the product passes through a common discharge chute of a combination weighing system, said combination weighing system comprising a plurality of weighing scales feeding said common discharge chute, said process comprising the steps of:

performing a first search of said plurality of scales for a first selected combination of scales which contains a combined quantity of product near a target weight, a first one of said scales being excluded from participation in said search, and correspondingly be excluded from the selected combination, dumping the first selected combination down the discharge chute,
depositing an object containing metal into said first scale,
performing a second search of said plurality of scales after said step of depositing to locate a second selected combination which includes the first scale and contains a combined quantity of product near to said target weight when the quantity of product in the first scale is included,
dumping the second selected combination including the object and product of the first scale down the discharge chute, and
noting the response of said metal detector to said object containing metal during the step of dumping the second selected combination.

2 more elements

In a combination weighing and packaging system having a plurality of weighing scales, a first computer means coupled to said weighing scales for determining combinations of said scales which contain a combined quantity of product near a target weight, a common discharge chute for said weighing scales, and a metal detector positioned to monitor product as it passes through said common discharge chute, the improvement comprising:

second computer means programmable by an operator to initiate a metal detector test operation,
third computer means responsive to the initiation of said metal detector test operation for holding a first of said scales out of at least one combination search performed by said first computer means after said metal detector test operation is initiated, and
fourth computer means for forcing the first computer means to select a test combination which includes said first scale after a test object containing metal has been deposited in said first scale and said metal detector test operation has been initiated.

In a combination weighing system having a plurality of weighing scales, a first computer means coupled to said weighing scales for searching for and determining combinations of said scales which contain a combined quantity of product near a target weight, a discharge chute for said weighing scales, and a metal detector kpositioned to monitor product as it passes through said discharge chute, the improvement comprising:

second computer means for periodically initiating a metal detector test operation,
third computer means responsive to the initiation of said metal detector test operation for holding a first one of said scales out of at least one combination search performed by said first computer means after said metal detector test operation is initiated, and
fourth computer means for forcing the first computer means to select another combination which includes said first scale after a test object containing metal is deposited in said first scale and said metal detector test operation is initiated, and
mechanical means responsive to said second computer means for automatically delivering said test object to said first scale after said test operation is initiated.

1 more element

Dependencies are inferred from the claim text.

Metal detector testing process and apparatus in a combination weighing system

Life of this patent

Metal detector testing process and apparatus in a combination weighing system

Life of this patent

Abstract

Claims19