The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 08, 2003
Filed:
Aug. 29, 2001
Ari Kiviniitty, Hämeenlinna, FI;
KCI Konecranes International, PLC, Hyvinkaa, FI;
Abstract
A method and an apparatus for measuring a load of a hoisting apparatus, where electricity is used as the driving force and a squirrel cage motor as the hoisting motor for moving a load attached to a hoisting member of the hoisting apparatus substantially in the vertical direction. The method and arrangement are employed to determine air gap torque of the hoisting motor, which describes the load of the hoisting apparatus, utilizing magnetization flux of the hoisting motor determined on the basis of the current, supply voltage and stator winding resistance of the hoisting motor. The value of the air gap torque is compared with an air gap torque curve determined for the hoisting apparatus at known reference loads to determine the load that corresponds to the air gap torque in question.