Cabinet cooling fan

Abstract

An electric fan core having a generally rectilinear shape, a positive pressure side, and a vacuum side is disclosed. A fan bracket attached to the positive pressure side of the electric fan core and offset from the fan core thereby defining a gap between the fan core and the fan bracket, the gap having a width less than an amount required to sustain a Venturi effect air intake when the electric fan core is in an operating state is disclosed. A grille attached to the vacuum side of the fan core and having a grille face that is offset from the fan core, the offset being greater than an amount of offset required to reduce turbulence noise from the grille face when the electric fan core is in an operating state is also disclosed.

1 . An electronic cooling fan assembly comprising: 
 an electric fan core having a generally rectilinear shape, a positive pressure side, and a vacuum side;    a fan bracket attached to the positive pressure side of the electric fan core and offset from the fan core thereby defining a gap between the fan core and the fan bracket, the gap having a width less than an amount required to sustain a Venturi effect air intake when the electric fan core is in an operating state; and    a grille attached to the vacuum side of the fan core and having a grille face that is offset from the fan core, the offset being greater than an amount of offset required to reduce turbulence noise from the grille face when the electric fan core is in an operating state.    
   
   
       2 . The electronic cooling fan assembly of  claim 1 , further comprising a set of elastic grommets interposing the fan bracket and the electric fan core.  
   
   
       3 . The electronic cooling fan assembly of  claim 1 , further comprising at least one stress relief cord attached to the fan bracket, the at least one stress relief cord being adapted to retain at least one lead wire in proximity to the electric fan core.  
   
   
       4 . The electronic cooling fan assembly of  claim 1 , wherein the fan bracket has a fan shroud that is substantially cylindrical and defines at least one bendable mounting tab, the at least one mounting tab defining a mounting hole that receives a fastener.  
   
   
       5 . The electronic cooling fan assembly of  claim 4 , wherein the fastener is a captive screw.  
   
   
       6 . The electronic cooling fan assembly of  claim 5 , wherein the shroud further defines at least one bendable stabilization tab, the at least one stabilization tab being offset by approximately 90 degrees on the circumference of the shroud from the at least one stabilization tab.  
   
   
       7 . The electronic cooling fan assembly of  claim 1 , further comprising: 
 a switch having a trigger input, an electrical input, and an electrical output;    wherein the electrical output is connected to the electric fan core and the switch activates the electrical output in response to a predetermine triggering current and voltage on the trigger input.    
   
   
       8 . The electronic cooling fan assembly of  claim 7 , further comprising, a second electrical output that provides power in parallel with the first electrical output.  
   
   
       9 . The electronic cooling fan assembly of  claim 8 , further comprising a second electric fan core connected to the second electrical output.  
   
   
       10 . The electronic cooling fan assembly of  claim 1 , wherein the fan bracket has a two piece construction including a generally cylindrical fan shroud and a flange attached to the fan shroud, the flange being attached to the electric fan core.  
   
   
       11 . The electronic cooling fan assembly of  claim 1 , further comprising a thermal switch configured to selectively activate the electric fan core when an ambient temperate reaches a predetermined threshold.  
   
   
       12 . The electronic cooling fan assembly of  claim 11 , wherein the thermal switch deactivates the electric fan core when the ambient temperature stays below a predetermined minimum threshold for a predetermined amount of time.  
   
   
       13 . A fan mounting bracket for reducing noise and vibration in an enclosure, the bracket comprising: 
 a generally cylindrical shroud having a circumference and first and second ends, the shroud providing first and second mounting tabs substantially on opposite sides of the circumference on the first end, the mounting tabs each defining a fastening hole, the shroud also providing first and second stabilization tabs on substantially opposites side of the circumference on the fist end and being offset approximately 90 degrees from the mounting tabs;    a mounting flange attached to the second end of the shroud and defining a plane substantially orthogonal to an axis of the shroud, the mounting flange defines a plurality of fan attachment holes; and    a plurality of elastic grommets;    wherein one of the plurality of elastic grommets is inset into each one of the plurality of fan attachment holes.    
   
   
       14 . The fan mounting bracket of  claim 13 , wherein the grommets are sized such that a Venturi effect gap is created when the mounting bracket is attached to a fan core via the fan attachment holes.  
   
   
       15 . The fan mounting bracket of  claim 13 , wherein the shroud and the mounting flange are made substantially from sheet metal.  
   
   
       16 . The fan mounting bracket of  claim 13 , wherein the elastic grommets are substantially made from silicon.  
   
   
       17 . A method of reducing noise and vibration from a fan core operating to cool a container through an air vent, the method comprising: 
 attaching a flanged shroud to the fan core with noise and vibration isolating grommets;    attaching a grille to the fan core such that a face of the grille is offset from the fan core, the offset being at least a distance necessary to reduce turbulence noise through the grille face; and    affixing the shroud to the air vent.    
   
   
       18 . The method of  claim 17 , further comprising securing a power lead to the shroud in proximity to the fan core such that a length of the power lead spanning a distance from the shroud to the fan core is relaxed.  
   
   
       19 . The method of  claim 17 , further comprising selectively engaging the fan core with a thermal switch.  
   
   
       20 . The method of  claim 17 , wherein the step of affixing the shroud further comprises attaching the shroud to the air hole such that the shroud protrudes into the air vent with at least one mounting tab on the shroud being attached to an area surrounding the air vent and at least one stabilizing tab on the shroud being substantially flush against the area surrounding the air vent.