Convective cushion with positive coefficient of resistance heating mode

Abstract

A cushion that is heated convectively using a positive coefficient of resistance type resistive heating element that is provided with heat exchanging surfaces, includes a mattress pad, seat or the like with a bottom surface secured around its perimeter to an air permeable top surface, forming a plenum and containing tubular spacer material therein. The plenum is connected to a power unit housing a blower, a heating module and a controller unit. The heating module preferably includes a PTC type heating element in conduction with a base plate and a number of heat exchanger fins. Preferably the heating element is sandwiched between a pair of the base plates and the heat exchanger fins, and there is a seal between the base plates to minimize air flow from the blower from passing there between. A remote control for the user's convenience may be provided, and a foldable antenna attachable to the convective unit facilitates wireless communication between the remote control and controller unit. The user resting atop the cushion is able to control the blower and heating module to deliver air of a desired temperature and quantity to the cushion and through the top surface. The invention advantageously replaces the current carrying, conductive wires and insulation found inside prior art heated mattresses, enhancing safety and performance while at the same time offering a cooled or ventilated capability.

1 . A selectively-controlled convective cushion comprising: 
 a plenum defined by a bottom surface secured around its perimeter to a generally air permeable top surface and containing tubular spacer material therein;    a power unit located remote from the plenum but in fluid communication with the plenum, and housing a blower in fluid communication with a heating module;    a controller unit in communication with the blower and the heating element;    whereby a user resting atop the cushion is able to control the blower and heating module to deliver air of a desired temperature and quantity to the cushion and through the top surface.    
   
   
       2 . The selectively-controlled convective cushion of  claim 1  wherein the plenum has an opening at one end, and further comprising an air duct with one end sized to be received into the plenum opening and a second end extending to the power unit.  
   
   
       3 . The selectively-controlled convective cushion of  claim 1  wherein the heating module comprises a PTC type heating element in conduction with a base plate and a plurality of heat exchanging fins.  
   
   
       4 . The selectively-controlled convective cushion of  claim 3  wherein the heating element is sandwiched between a pair of the base plates and the plurality of heat exchanging fins.  
   
   
       5 . The selectively-controlled convective cushion of  claim 4  further comprising a seal between the base plates to minimize air flow from passing there between.  
   
   
       6 . The selectively-controlled convective cushion of  claim 1  further comprising a remote control in communication with the controller unit.  
   
   
       7 . The selectively-controlled convective cushion of  claim 6  further comprising a foldable antenna attachable to the power unit to facilitate wireless communication between the remote control and controller unit.  
   
   
       8 . The selectively-controlled convective cushion of  claim 8  wherein the controller unit includes a speed control for the blower.  
   
   
       9 . The selectively-controlled convective cushion of  claim 2  wherein the air duct comprises an outer shell and an inner insulating sleeve with an air gap there between.  
   
   
       10 . The selectively-controlled convective cushion of  claim 1  further comprising a vent at the opposing end of the plenum.  
   
   
       11 . The selectively-controlled convective cushion of  claim 1  wherein the bottom surface of the plenum is generally air impermeable.  
   
   
       12 . The selectively-controlled convective cushion of  claim 1  wherein the plenum is adapted to be placed on a conventional mattress.  
   
   
       13 . The selectively-controlled convective cushion of  claim 3  wherein the power unit comprises a plurality of PTC type heating elements.  
   
   
       14 . A convective mattress pad comprising: 
 a plenum defined by a bottom surface secured around its perimeter to a generally air permeable top surface, the plenum containing an air flow structure and having an opening at one end;    an air duct with one end sized to be received into the opening and a second end extending outside the plenum;    a power unit housing a blower in fluid communication with a heating module and connected to the second end of the air duct;    a controller unit in communication with the blower and the heating element; and,    wherein the heating module comprises a PTC type heating element in conduction with a base plate and a plurality of heat exchanging fins.    
   
   
       15 . The mattress pad of  claim 14  wherein the heating element is sandwiched between a pair of the base plates and the plurality of heat exchanging fins.  
   
   
       16 . The mattress pad of  claim 14  further comprising a seal between the base plates to minimize air flow from the blower from passing there between; and  
   
   
       17 . The mattress pad of  claim 14  further comprising a remote control in communication with the controller unit.  
   
   
       18 . The mattress pad of  claim 17  further comprising a foldable antenna attachable to the power unit to facilitate wireless communication between the remote control and controller unit.  
   
   
       19 . The mattress pad of  claim 14  wherein the controller unit includes a speed control for the blower.  
   
   
       20 . The mattress pad of  claim 14  wherein the air duct comprises an outer shell and an inner insulating sleeve with an air gap there between.  
   
   
       21 . The mattress pad of  claim 14  further comprising a vent at the opposing end of the plenum.  
   
   
       22 . The mattress pad of  claim 14  wherein the air flow structure is tubular spacer material.