Drain pan overflow safety switch

Abstract

A safety switch prevents overflow of condensate that collects in the drain pan of an air-cooling system. The overflow safety switch attaches to the condensate drainage system and is electrically connected to a circuit of the air-cooling system, a power circuit, a control circuit and/or an alarm circuit. The switch includes a tube that extends within the condensate drain pan or any other water conducting point in the condensate drainage system. A reed switch is sealed within the tube and a float containing a magnet is moveably supported on the exterior of the tube. The float ascends or descends in response to the level of the liquid condensate within the drain pan. As the float moves relative to the tube, the magnet causes the reed switch to open, thereby interrupting operation of the air-cooling system and/or actuating the alarm circuit.

1 . An overflow safety switch for a drain system having a drain pan, drain pan outlets, and pipes in fluid flow communication with the drain pan and extending therefrom, said overflow safety switch comprising: 
 a tubular member;    a mounting assembly for attaching said overflow safety switch to the drain system so that at least a portion of said tubular member extends within the drain system;    a float body moveably supported on said tubular member and being structured and disposed to move relative to said tubular member, between a first position and a second position, in response to a change in liquid level in the drain system;    at least one magnetic element carried by said float body; and    a reed switch connected to electric conductors and sealed within said tubular member, said reed switch being magnetically responsive to said at least one magnetic element in a manner which causes said reed switch to close when said float body is at said first position thereby permitting electric current flow through the electric conductors, and which further causes said reed switch to open when said float body moves to said second position thereby interrupting electric current flow through the electric conductors.    
   
   
       2 . The overflow safety switch as recited in  claim 1  wherein said mounting assembly comprises: 
 a clip structured and disposed for removable attachment to a side wall of the drain pan.    
   
   
       3 . The overflow safety switch as recited in  claim 2  wherein said clip is structured for attachment to said tubular member for supporting said tubular member in a vertical, upright position within the drain pan.  
   
   
       4 . The overflow safety switch as recited in  claim 3  wherein said clip extends between said tubular member and the side wall of the drain pan to support said tubular member in spaced relation to the side wall of the drain pan with said float body positioned within the drain pan.  
   
   
       5 . The overflow safety switch as recited in  claim 4  wherein said clip is structured and disposed for adjustably positioning said tubular member relative to the reservoir of the drain pan.  
   
   
       6 . The overflow safety switch as recited in  claim 5  wherein said clip is structured and disposed to permit vertical adjustment of said tubular member relative to the reservoir and a bottom of the drain pan.  
   
   
       7 . The overflow safety switch as recited in  claim 1  wherein said mounting assembly comprises: 
 a through hole formed through the drain system and sized for sealed passage of said tubular member therethrough.    
   
   
       8 . The overflow safety switch as recited in  claim 7  wherein said mounting assembly further comprises: 
 an O-ring or other seal for providing a liquid tight seal about said tubular member and said through hole.    
   
   
       9 . The overflow safety switch as recited in  claim 7  wherein said tubular member includes screw threads formed about an outer surface for threaded engagement with the through hole.  
   
   
       10 . The overflow safety switch as recited in  claim 9  wherein said tubular member is adjustably positionable relative to the drain pan.  
   
   
       11 . An overflow safety switch device for a drain system having a reservoir for collecting liquid, said overflow safety switch device comprising: 
 an elongate housing;    a mounting structure for supporting said housing within the reservoir;    a magnetically driven reed switch connected to electric conductors and sealed within said housing;    a float body moveably captivated on an exterior of said housing and moveable relative to said housing, between a first position and a second position, in response to a change in liquid level in the reservoir;    at least one magnetic element carried by said float body and positioned and disposed to magnetically drive said reed switch between a closed circuit position, thereby enabling electric current flow through the conductors and an open circuit position, thereby interrupting electric current flow through the conductors, as said float body moves between said first and second positions.    
   
   
       12 . The device as recited in  claim 11  wherein said mounting structure comprises: 
 a clip structured and disposed for removable attachment to the drain system.    
   
   
       13 . The device as recited in  claim 12  wherein said clip is structured for attachment to said elongate housing for supporting said elongate housing in a vertical upright position with said float body positioned within the reservoir.  
   
   
       14 . The device as recited in  claim 13  wherein said clip is structured and disposed for adjustably positioning said housing relative to the reservoir.  
   
   
       15 . The device as recited in  claim 11  wherein said mounting structure comprises: 
 a through hole formed through the drain system and sized for water sealed passage of said housing therethrough.    
   
   
       16 . The device as recited in  claim 15  wherein said housing includes screw threads formed about an outer surface for threaded engagement with the through hole in the drain system.  
   
   
       17 . An overflow safety switch device for a liquid collecting drain pan, said overflow safety switch device comprising: 
 an elongate housing;    a mounting structure for supporting said housing within the drain pan;    a magnetically driven reed switch sealed within said housing and including a pair of contacts each connected to an electric conductor and operable between a closed circuit position wherein said contacts are touching one another, and an open circuit position wherein said contacts are separated from one another;    a float body moveably captivated on an exterior of said housing and moveable relative to said housing, between a first position and a second position, in response to a change in liquid level in the drain pan; and    at least one magnetic element carried by said float body and being positioned and disposed to magnetically influence said contacts of said reed switch in a manner which causes said contacts to move between said closed circuit position and said open circuit position as said float body moves between said first and second positions.    
   
   
       18 . The device as recited in  claim 17  wherein said mounting structure comprises: 
 a clip structured and disposed for removable attachment to the drain pan, and said clip being structured for supporting said housing in a vertical, upright position within the drain pan.    
   
   
       19 . The device as recited in  claim 18  wherein said clip is structured and disposed for adjustably positioning said housing relative to the drain pan.  
   
   
       20 . The device as recited in  claim 17  wherein said mounting structure comprises: 
 a through hole formed through the drain pan and sized for water-tight, sealed passage of said housing therethrough.