US3679321A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prestressed flexible bladed fan
Assignee: Siemens Bendix Automotive Electronics Ltd
•
Filing: 1971-04-26
•
Granted: 1972-07-25
•
Expires: 1991-04-26
Abstract
Abstract A fan having a hub, a plurality of arms extending radially outwardly of the hub, blades, one secured to each arm, which decamber as rotational speed increases, and biasing members, one connected to each arm contacting the associated blade and urging such blade member toward its decambered position and thereby prestressing said blade member.
Inventors
- 👤 Karl H Strick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:21
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/32; F04D29/38; F04D29/382
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
90 words
In a fan having a hub and a plurality of fan blade assemblies each comprising an arm extending radially outwardly from said hub and a flexible, resilient blade connected to said arm which blade decambers from a downstream position, relative to the direction of airflow, to a relatively more upstream position as rotational speed increases, that improvement comprising: a resilient biasing member provided in each of said fan blade assemblies connected thereto and contacting said blade thereof urging said blade toward its decambered upstream position and thereby prestressing said blade.
Claim 2
Dependent Claim
90 words
In a fan having a hub and a plurality of fan blade assemblies each comprising an arm extending radially outwardly from said hub and a flexible, resilient blade connected to said arm which blade decambers from a downstream position, relative to the direction of airflow, to a relatively more upstream position as rotational speed increases, that improvement comprising: a resilient biasing member provided in each of said fan blade assemblies connected thereto and contacting said blade thereof urging said blade toward its decambered upstream position and thereby prestressing said blade.
Claim 3
Dependent Claim
68 words
The fan claimed in claim 1 in which said biasing member has a curved configuration with the portion of said biasing member contacting said blade extending toward the upstream side of said fan, contacting and prestressing said blade at the most decambered position thereof during rotation of said fan at a predetermined maximum speed, whereby said biasing member contacts and prestresses said blade throughout its range of motion.
Claim 4
Dependent Claim
59 words
The fan claimed in claim 1 in which said blade defines, in the direction of fan rotation, a generally radially extending leading portion which is relatively rigid and a trailing portion which is flexible, said biasing member being connected to said assembly adjacent said leading portion and contacting said blade on the downstream side thereof at said trailing portion.
Claim 5
Dependent Claim
41 words
The fan claimed in claim 3 in which said biasing member contacts said blade at said trailing portion continuously throughout the radial extent thereof along a line generally parallel to a generally radially extending leading edge defined by said leading portion.
Claim 6
Dependent Claim
69 words
The fan claimed in claim 3 in which said fan blade assembly includes a reinforcement member adjacent said leading portion on the upstream side of said blade, said reinforcement member extending and terminating toward said trailing portion in spaced relationship thereto, and said biasing member contacting said blade between a trailing edge of said blade defined by said trailing portion and the point at which said reinforcement member terminates.
Claim 7
Dependent Claim
67 words
The fan claimed in claim 3 in which said biasing member comprises a base portion extending radially continuously along said leading portion and a plurality of integral triangular biasing fingers extending therefrom toward their apices at said trailing portion said biasing member bearing upon said trailing portion adjacent said apices along a line generally parallel to a generally radially extending leading edge defined by said leading portion.
Claim 8
Dependent Claim
33 words
The fan claimed in claim 6 in which said apices are interconnected by a continuous integral outer web of said biasing member said outer web contacting said trailing portion continuously along said line.
Claim 9
Dependent Claim
62 words
The fan claimed in claim 7 in which said biasing member has a curved configuration with said outer web extending toward the upstream side of said fan, contacting and prestressing said blade at the most decambered position thereof during rotation of said fan at a predetermined maximum speed, whereby said biasing member contacts and prestresses said blade throughout its range of motion.
References Cited (Backward Citations)
FR368039A
Cited
US991331A
Cited
DE559674C
Cited
US2132133A
Cited
US2374342A
Cited
US3044557A
Cited
US3289924A
Cited
US3373930A
Cited
US3356154A
Cited
US3406760A
Cited
US3490686A
Cited
US3594098A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |