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:
Jul. 17, 2007
Filed:
Sep. 18, 2001
Bengt Kallman, Leksand, SE;
Hans-olof Frojd, Gavle, SE;
Bengt Kallman, Leksand, SE;
Hans-Olof Frojd, Gavle, SE;
3M Innovative Properties Company, St Paul, MN (US);
Abstract
A method and configuration from maintaining a constant of air to a protective helmet () from a fan () in a battery powered fresh air unit. The fan () is a radial fan with a filter () positioned on the suction side of the fan and is operated by a brushless continuous current motor (). With the aid of signals from position sensors () in the motor (), a control unit () can determine the speed of the fan (). The control unit also detects the motor's power consumption and compares this and the speed with a characteristic curve for the motor () for a given flow from the fan, which is stored in a memory (). In the event of any deviation, the control unit () regulates a change of the voltage supply to the motor () so that the deviation is reduced.