US 4,221,576 A · Automatic air filter changer

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.

Claims10

Dependent claims

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.

5 more elements

Dependencies are inferred from the claim text.

Automatic air filter changer

Life of this patent

Automatic air filter changer

Life of this patent

Abstract

Claims10