US4818183A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low impedance fan safety guard
Assignee: SCHAEFER RONALD E TRUSTEE
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Filing: 1987-12-03
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Granted: 1989-04-04
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Expires: 2007-12-03
Abstract
Abstract A low impedance safety guard for an air circulating fan with rotating fan blades which prevents a human hand, finger or foot from getting into the path of the rotating blades while yet achieving the unrestrictive air stream benefits of a relatively open guard which is generally considered unsafe. The guard comprises rear and front parallel and opposing substantially open, air stream unobstructive fan blade guard faces which will permit the hand, finger or foot to pass partially therethrough. A substantially closed circumferential wall is provided which connects the rear and front faces to enclose the fan blades approximately equal distant from the respective faces to prohibit the hand, figure or foot from reaching the blade path after passing partially through either face should a person unfortunately attempt to do so.
Inventors
- 👤 Ronald E. Schaefer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:23
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/70; Y; Y10; Y10T; Y10T74/00; Y10T74/21; Y10T74/219
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
140 words
A low impedance safety guard for an air circulating fan with rotating fan blades which prevents a human hand, finger or foot from getting into the path of the rotating fan blades while yet achieving the unrestrictive air stream benefits of a relatively open guard which is generally considered unsafe, comprising: (a) rear and front parallel and opposing substantially open, air stream unobstructive fan blade guard faces in front and behind the fan blades, respectively, which will permit the hand, finger or foot to pass partially therethrough; (b) a substantially closed circumferential wall located about the rotatable fan blades; and (c) means for connecting the faces and circumferential wall together to enclose the fan blades approximately equal distant from the respective faces to prohibit the hand, finger or foot from reaching the blade path after passing partially through either face.
Claim 2
Dependent Claim
140 words
A low impedance safety guard for an air circulating fan with rotating fan blades which prevents a human hand, finger or foot from getting into the path of the rotating fan blades while yet achieving the unrestrictive air stream benefits of a relatively open guard which is generally considered unsafe, comprising: (a) rear and front parallel and opposing substantially open, air stream unobstructive fan blade guard faces in front and behind the fan blades, respectively, which will permit the hand, finger or foot to pass partially therethrough; (b) a substantially closed circumferential wall located about the rotatable fan blades; and (c) means for connecting the faces and circumferential wall together to enclose the fan blades approximately equal distant from the respective faces to prohibit the hand, finger or foot from reaching the blade path after passing partially through either face.
Claim 3
Dependent Claim
11 words
The safety guard of claim 1 wherein the means is releasable.
Claim 4
Dependent Claim
63 words
The safety guard of claim 1 wherein the connecting means comprises at least three radially extending ribs fixed on to either of the faces each having a substantially right-angled portion with an end wherein the angled portion is directed inwardly of the guard and the end being adapted to catch onto the adjacent circumferential wall for connecting the faces with the circumferential wall.
Claim 5
Dependent Claim
58 words
The safety guard of claim 1 wherein the front and rear faces each comprise a group of concentric wire rings spaced apart from one another as to not unduly interfere with the airstream while yet prohibiting the human hand, finger or foot to pass between and substantially beyond the rings to the vicinity of the fan blade path.
Claim 6
Dependent Claim
31 words
The safety guard of claim 4, further comprising at least three radially extending ribs for each face fixed onto the rings of each face for fixedly holding the rings in alignment.
Claim 7
Dependent Claim
45 words
The safety guard of claim 5 wherein the connecting means comprises a substantially right-angled portion of each rib directed inwardly of the guard having an end, the end and the circumferential wall being adapted to interlock the rear and front faces with the circumferential wall.
Claim 8
Dependent Claim
39 words
The safety guard of claim 1 wherein the substantially closed circumferential connecting wall comprises substantially parallel and equal diameter coaxial rings which are sufficiently close together to prohibit the human hand, finger or foot to pass between the rings.
Claim 9
Dependent Claim
137 words
A low impedance safety guard for an air circulating fan with a rotating blade which prevents a hand, finger or foot from getting into the path of the rotating blades while yet achieves the unrestricted air stream benefits of a relatively open guard which is generally considered unsafe, comprising: (a) two cylindrically-shaped guard halves each comprising: one open end; (ii) a substantially closed circumferential wall portion; and (iii) a substantially open, air stream unobstructive fan blade guard face opposing the open end which will permit the hand, finger or foot to pass partially therethrough; and (b) interconnecting means for connecting the adjacent open ends of the guard halves together to enclose the fan blades approximately equal distance from the respective faces to prohibit the hand, finger or foot from reaching the blade path after passing partially therethrough.
Claim 10
Dependent Claim
137 words
A low impedance safety guard for an air circulating fan with a rotating blade which prevents a hand, finger or foot from getting into the path of the rotating blades while yet achieves the unrestricted air stream benefits of a relatively open guard which is generally considered unsafe, comprising: (a) two cylindrically-shaped guard halves each comprising: one open end; (ii) a substantially closed circumferential wall portion; and (iii) a substantially open, air stream unobstructive fan blade guard face opposing the open end which will permit the hand, finger or foot to pass partially therethrough; and (b) interconnecting means for connecting the adjacent open ends of the guard halves together to enclose the fan blades approximately equal distance from the respective faces to prohibit the hand, finger or foot from reaching the blade path after passing partially therethrough.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-03 | 2000-10-03 | 2001-04-04 | $7700.00 | Window Closed / Lapsed |