Retractable magnetic sheet

Abstract

The invention is a retractable magnetic sheet. A cylindrical rod is biased in a first rotational direction to retract the sheet which is mounted at a first edge to the rod. The sheet is magnetically-receptive, which means magnets can attach to it. The sheet is extended by pulling downwardly against the bias until the ratchet locks the cylindrical rod's position. Upon pulling downwardly again, the ratchet releases and the rod retracts, winding the sheet up.

1 . An apparatus for providing a substrate to which a magnet can be attached, the apparatus comprising: 
 (a) a cylindrical rod having an axle about which said rod is rotatably mounted; and    (b) a sheet having a magnetically receptive region, the sheet having a first edge mounted to the cylindrical rod, a central region of the sheet winding circumferentially around the cylindrical rod and terminating in a second edge opposite the first edge, wherein the second edge is displaceable relative to the cylindrical rod's axle.    
     
     
         2 . The apparatus in accordance with  claim 1 , further comprising means for rotating the cylindrical rod in at least one direction.  
     
     
         3 . The apparatus in accordance with  claim 1 , further comprising a prime mover drivingly linked to the cylindrical rod for rotating the cylindrical rod in at least one direction.  
     
     
         4 . The apparatus in accordance with  claim 1 , further comprising a bias drivingly linked to the cylindrical rod for rotatably biasing the cylindrical rod in one direction.  
     
     
         5 . The apparatus in accordance with  claim 4 , wherein the bias biases the cylindrical rod in a sheet-retracting direction.  
     
     
         6 . The apparatus in accordance with  claim 5 , wherein the magnetically receptive region of the sheet includes substantially the entire sheet.  
     
     
         7 . The apparatus in accordance with  claim 6 , further comprising a ratchet mounted to the cylindrical rod near the axle, wherein the ratchet selectively stops rotation of the cylindrical rod in the retracting direction.  
     
     
         8 . The apparatus in accordance with  claim 7 , wherein the cylindrical rod is a circular cylinder.  
     
     
         9 . The apparatus in accordance with  claim 7 , wherein the cylindrical rod is an octagonal cylinder.  
     
     
         10 . An apparatus for providing a substrate to which a magnet can be attached, the apparatus comprising: 
 (a) a cylindrical rod having an axle about which the rod is rotatably mounted;    (b) a magnetically receptive sheet having a first edge mounted to the cylindrical rod, a central region of the sheet winding circumferentially around the cylindrical rod and terminating in a second edge opposite the first edge, wherein the second edge is displaceable relative to the cylindrical rod's axle; and    (c) means for rotating the cylindrical rod to retract the sheet from an extended position.    
     
     
         11 . An apparatus for providing a substrate to which a magnet can be attached, the apparatus comprising: 
 (a) a cylindrical rod having an axle about which the rod is rotatably mounted;    (b) a magnetically receptive sheet having a first edge mounted to the cylindrical rod, a central region of the sheet winding circumferentially around the cylindrical rod and terminating in a second edge opposite the first edge, wherein the second edge is displaceable relative to the cylindrical rod's axle; and    (c) a bias drivingly linked to the cylindrical rod for rotatably biasing the cylindrical rod in a sheet-retracting direction.    
     
     
         12 . An apparatus for providing a substrate to which a magnet can be attached, the apparatus comprising: 
 (a) a cylindrical rod having an axle about which the rod is rotatably mounted;    (b) a magnetically receptive sheet having a first edge mounted to the cylindrical rod, a central region of the sheet winding circumferentially around the cylindrical rod and terminating in a second edge opposite the first edge, wherein the second edge is displaceable relative to the cylindrical rod's axle;    (c) a bias drivingly linked to the cylindrical rod for rotatably biasing the cylindrical rod in a sheet-retracting direction; and    (d) a ratchet mounted to the cylindrical rod near the axle, wherein the ratchet selectively stops rotation of the cylindrical rod in the sheet-retracting direction.    
     
     
         13 . The apparatus in accordance with  claim 12 , wherein the cylindrical rod is a circular cylinder.  
     
     
         14 . An apparatus for providing a substrate to which a magnet can be attached, the apparatus comprising: 
 (a) a rotatable cylindrical rod having an axis of rotation;    (b) a sheet having a magnetically receptive region, the sheet having a first edge mounted to the cylindrical rod, a central region of the sheet winding circumferentially around the cylindrical rod and terminating in a second edge opposite the first edge, wherein the second edge and the cylindrical rod's axis of rotation relatively are displaceable.    
     
     
         15 . An apparatus for providing a substrate to which a magnet can be attached, the apparatus comprising: 
 (a) a cylindrical rod having an axle about which the rod is rotatably mounted;    (b) a magnetically receptive sheet having a first edge mounted to the cylindrical rod, a central region of the sheet winding circumferentially around the cylindrical rod and terminating in a second edge opposite the first edge, wherein the second edge is displaceable relative to the cylindrical rod's axle;    (c) a bias drivingly linked to the cylindrical rod for rotatably biasing the cylindrical rod in a sheet-retracting direction; and    (d) a magnet removably mounted to a major surface of the sheet.