Patent US4221576A successfully refreshed from Google Patents.
US4221576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic air filter changer
Assignee: Individual
•
Filing: 1979-01-19
•
Granted: 1980-09-09
•
Expires: 1999-01-19
Abstract
Abstract The changer includes a filter supporting frame attached to a supply spool containing fresh filter material and a take-up spool for storing the clogged filter material. The frame is substantially rectangular in shape and has attached thereto a sensor switch which is disposed medially of the frame and the filter material disposed thereacross. The switch is actuated when the filter material becomes clogged to a point where deflection of the material in response to circulating air flow occurs. The switch actuates a drive motor attached to the take-up spool causing the take-up spool to wind the clogged material thereon thereby replacing it with clean filter material from the supply spool. The filter material itself contains transverse enlarged linear elements which are longitudinally spaced along the filter material at intervals equivalent to the width of the frame. The enlarged areas actuate a switch which causes cessation of the motor drive, thereby insuring accurate placement of the fresh filter material.
Inventors
- 👤 Robert E. Phillips, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:36
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/18; B01D46/20; B01D46/42; B01D46/44; B01D46/46
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
196 words
An apparatus for replacing clogged filter material with fresh filter material comprising: a frame having a substantially planar open center area; a first spool rotatably attached to said frame and having an axis parallel to the plane of said open center; a second spool rotatably attached to said frame and having an axis parallel to the plane of said open center; a length of substantially planar filter material having a portion thereof wound about said first spool, said filter material extending from said first spool across said open center and having a second portion thereof wound about said second spool; forced air circulation means for causing a flow of air through said filter material in said open center; clogged filter sensing means disposed adjacent said filter material in said open center for sensing an increased deflection of said filter material in response to clogging of said filter material; power means for rotating said second spool in response to said clogged filter sensing means; and filter replacement measuring means at least partially affixed to said filter material for stopping rotation of said second spool when said open center of said frame is filled with fresh filter material.
Claim 2
Independent Claim
196 words
An apparatus for replacing clogged filter material with fresh filter material comprising: a frame having a substantially planar open center area; a first spool rotatably attached to said frame and having an axis parallel to the plane of said open center; a second spool rotatably attached to said frame and having an axis parallel to the plane of said open center; a length of substantially planar filter material having a portion thereof wound about said first spool, said filter material extending from said first spool across said open center and having a second portion thereof wound about said second spool; forced air circulation means for causing a flow of air through said filter material in said open center; clogged filter sensing means disposed adjacent said filter material in said open center for sensing an increased deflection of said filter material in response to clogging of said filter material; power means for rotating said second spool in response to said clogged filter sensing means; and filter replacement measuring means at least partially affixed to said filter material for stopping rotation of said second spool when said open center of said frame is filled with fresh filter material.
Claim 3
Dependent Claim
43 words
The apparatus of claim 1 wherein said clogged filter sensing means is disposed medially of said open center and on the opposite side of said filter material in said open center from the direction of air circulation from said forced air circulation means.
Claim 4
Dependent Claim
39 words
The apparatus of claim 2 and further including mounting means for adjustably mounting said clogged filter sensing means for enabling an adjustment of the distance between said clogged filter sensing means and said filter material in said open center.
Claim 5
Dependent Claim
34 words
The apparatus of claim 1 wherein said filter replacement measuring means includes said filter material having spaced areas of increased cross section; and means for sensing said spaced areas of the increased cross section.
Claim 6
Dependent Claim
37 words
The apparatus of claim 4 wherein said means for sensing said areas of increased cross section includes a normally closed switch, said switch being rendered open upon contact with one of said areas of increased cross section.
Claim 7
Dependent Claim
102 words
The apparatus of claim 5 wherein said clogged filter sensing means includes a normally open switch which is rendered closed upon deflection of said clogged filter, said normally open switch being in electrical parallel circuit with said normally closed switch; and further wherein said power means includes an electric motor drivingly connected to said second spool, said electric motor being in series electrical circuit with said parallel combination of said normally open and normally closed switches and further in series with the source of electrical supply, said normally open and normally closed switches comprising the sole control components for the electric motor.
Claim 8
Dependent Claim
150 words
A filter changing apparatus for facilitating the replacement of clogged filter material in a forced air circulation system with fresh filter material comprising a frame means for holding filter material in an air flow stream in said forced air circulation system; a length of substantially planar filter material; a light metal mesh disposed in said frame in supporting relation to the filter material; a switch means disposed medially of said frame for actuation upon the clogging of said filter material causing a greater deflection of said filter material in response to said air flow; supply means for supplying said filter material to said frame; take-up means for removing clogged filter material from said frame; and power means for removing said filter material from said supply means for replacing the filter material in said frame and simultaneously removing the filter material from said frame and storing it on the take-up means.
Claim 9
Dependent Claim
150 words
A filter changing apparatus for facilitating the replacement of clogged filter material in a forced air circulation system with fresh filter material comprising a frame means for holding filter material in an air flow stream in said forced air circulation system; a length of substantially planar filter material; a light metal mesh disposed in said frame in supporting relation to the filter material; a switch means disposed medially of said frame for actuation upon the clogging of said filter material causing a greater deflection of said filter material in response to said air flow; supply means for supplying said filter material to said frame; take-up means for removing clogged filter material from said frame; and power means for removing said filter material from said supply means for replacing the filter material in said frame and simultaneously removing the filter material from said frame and storing it on the take-up means.
Claim 10
Dependent Claim
46 words
The apparatus of claim 7 wherein said switch means is mounted medially of a mounting member having one end pivotally connected to said frame and the opposite end connected to said frame through an adjustment means for controlling the distance from said member to said frame.
Claim 11
Dependent Claim
31 words
The apparatus of claim 8 wherein said switch means is electrically connected to a circuit including a warning light for giving an indication of the clogged condition of said filter material.
Claim 12
Dependent Claim
31 words
The apparatus of claim 8 wherein said switch is connected to an electric circuit including an electric motor for causing a powered exchange of fresh filter material for clogged filter material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-09 | 1984-03-10 | 1984-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-09 | 1988-03-10 | 1988-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-09 | 1992-03-10 | 1992-09-09 | $7700.00 | Window Closed / Lapsed |