Blow filter device
US8118025B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 2005 |
| Grant date | Feb 21, 2012 |
| Priority date | — |
| Expiry date | Oct 21, 2027 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA62B17/04
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A blow filter device for breathing masks and hoods, comprising a blower which is driven by a motor and at least one filter which is arranged upstream from the blower, in addition to an electronic control system for adjusting a predefined airflow volume. The invention is characterized in that the motor is an electronically commutated direct current motor (6) which is controlled with the aid of a pulse width modulation ratio as a control variable, wherein a calibrating curve is created and stored in the memory (14) of the electronic control system and is based on a plurality of different filter resistances and a respectively corresponding pulse-width modulation ratio (PWM) and the respective motor speed (n) for a specific volume of air. The direct current motor can be controlled in the hood mode according to the speed (n) measured in relation to the respective filter resistance after activation with the aid of the associated pulse-width modulation ratio read from the calibrating curve and can be controlled in the mask mode independently of the respective filter resistance with a respective specific constant pulse-width modulation ratio (PWM) for the associated mask type, wherein the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.