Low noise fan
US5967747A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 1998 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Jan 20, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04D17/16
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
A collectorless vacuum fan for floor maintenance machines has a backplate with an inlet plate attached thereto in spaced relationship, and an impeller between the backplate and inlet plate. Both the backplate and the inlet plate extend radially beyond the periphery of the impeller. A shaft mounts the impeller for rotation. The inlet plate has a central opening providing air to the hub of the impeller. Vanes on the impeller discharge air out through a diffuser channel defined by the space between the inlet plate and the backplate outside the periphery of the impeller. Attachment elements for mounting the inlet plate on the backplate leave the diffuser channel substantially unobstructed so that air is discharged about the entire periphery of the impeller. The fan has increased air flow compared to a conventional fan having an integral collector housing and decreased noise compared to a fan having a 360 degree discharge and no diffuser.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.