Patent Publication Number: US-6711767-B2

Title: Apparatus for warming a bed

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of U.S. Provisional Patent Application No. 60/352,741 filed Jan. 30, 2002. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT NOT APPLICABLE 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to devices for warming a bed, and particularly to electrically powered devices that blow heated air between bed covers. 
     2. Description of the Related Art 
     During the winter in cold climates, an unoccupied bed becomes relatively cold. Thus a person entering the bed is exposed to bedding surfaces which are considerably colder than human body temperature. It takes some time for the person&#39;s body heat to warm the bed. 
     Various devices have been created to talk the chill off of bedding so that a person upon entering the bed is not be exposed to cold surfaces in the winter. One common approach is to turn-on an electric blanket prior to entry into the bed to warm the region in which the person will sleep. Other devices supplied heated air into a space between the bed coverings. For example, U.S. Pat. No. 15,887,303 discloses a conduit which conducts air into the bed from a register of a forced air heating system of the building. However, that latter device does not evenly distribute the warm air throughout the bed and does not allow the user to control the temperature or flow of the air being forced into the bed. In addition, this latter system functions only with the normal thermostatically controlled heating system for the building. 
     SUMMARY OF THE INVENTION 
     A bed warming apparatus is provided to heat the bed covers prior to a person entering the bed on winter nights. This apparatus mounts on the bed being supported by elements that extend between the standard mattress and box spring. A fan forces room air through an electric heating coil in the apparatus and then through an outlet which directs the air flow between the bed covers. 
     The bed warning apparatus has a housing with an air inlet and an air outlet. A heater and a fan are contained within the housing with the fan producing a flow of air from the air inlet through the heater to the air outlet. A support is adjustably coupled to the housing and is adapted to extend under the mattress to hold the housing along an edge of the mattress in a position wherein the air flow from the air outlet is directed between the bed covers. 
     In a preferred embodiment of the housing, the air inlet is located on a bottom end with the air outlet located near the top of a side wall. A plurality of pails of apertures are located in the side wall with the pairs of apertures being stacked vertically. The support comprises first and second support legs selectively received in one of the pairs of apertures. Selection of the particular pair of apertures in which the first and second support legs are received adjusts a spatial relationship of the housing to the mattress so that the flow of air from the air outlet is directed between the mattress bed covering. 
     Another aspect of the present invention provides a user operable controller for activating the fan and the heater. Preferably the user operable controller enables the fan to be activated with and without activating the heater. An optional timer can be provided to deactivate the heater after a defined period of time. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a bed on which a first embodiment of a apparatus has been installed; 
     FIG. 2 is a side view of the bed and the warming apparatus; 
     FIG. 3 is a view of a side of the warming apparatus that faces the bed; 
     FIG. 4 is a cross-section view of the warming apparatus; 
     FIG. 5 is an isometric view of a bed on which a second embodiment of a warming apparatus has been installed; 
     FIG. 6 illustrates the relationship of an air distribution plenum of the second embodiment to the foot of the mattress; 
     FIG. 7 is a cross-sectional view along line  7 — 7  in FIG.  6  and furthering illustrating the installation of the air distribution plenum; and 
     FIG. 8 shows the fan and heater unit of the second bed warming apparatus 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With initial reference to FIGS. 1 and 2, an apparatus  10  is provided to warm a bed  12 , which has a conventional mattress  14  on top of a standard box spring  15 . The bed warming apparatus  10  has a housing  20  from which a pair of support legs  22  project between the mattress  14  and box spring  15  to hold the apparatus  10  at the foot of the bed  12 . As seen in FIG. 3, a surface  26  of the housing  20  that faces the bed has a plurality of apertures  24  arranged in two columns in which apertures in each columns are arranged horizontally in pairs. Each aperture  24  is sized to securely receive one of the support legs  22 . By placing the support legs  22  into different apertures  24  in each column, the spatial relationship (i.e. the height) of the apparatus  10  with respect to the top surface of the mattress  14  can be adjusted. 
     With continuing reference to FIG. 3, the upper portion of housing  20  has an air deflector plenum  28  with a horizontally elongated outlet aperture  30  through which air flows from the apparatus. The support legs  22  are positioned in apertures  24  so that when the legs are inserted between the mattress and box spring  14  and  15 , the outlet aperture  30  is above the upper surface of the mattress  14  and a lower sheet  32  thereon, as shown in FIG.  2 . Thus the legs  22  form an adjustable support for the bed warming apparatus  10 . When the bed  12  is made up for sleeping, the upper sheet  34  and any blanket, quilt or bedspread (not shown) are draped over the mattress  14  and the housing  20 . The upper sheet  34  and any other bedding hang over the housing  20  and are not tucked between the mattress and box spring  14  and  15 . This exposes an air inlet  36  at the bottom of the housing  20  so that air from beneath the bed is drawn upward into the housing, as will be described. 
     Referring to FIG. 4, the housing  20  has an interior wall  38  which divides the housing interior into inlet chamber  40 , a passage  46  and an outlet chamber  52 . The air inlet  36  opens into the inlet chamber  40 . An electric motor  42  is located within the inlet chamber  40  and has a shaft that extends through an aperture  44  in the wall  38  and into the U-shaped passage  46 . A conventional rotary fan  48  is attached within the passage  46  to the motor&#39;s shaft and rotates when the motor is energized. The fan  48  draws air from the inlet chamber  40  through the aperture  44  and forces the air along the passage  46 . An electric heating coil  50  is located within the passage  46  downstream of the fan  48  to heat the air flowing there through the passage  46  opens into the outlet chamber  52  through which the air travels via a housing aperture  54  into the air deflector plenum  28  and out through the outlet  30 . 
     A hand-held controller  56  enables the user to turn the bed warming apparatus  10  on and off and regulate the temperature of the heating element  50  and thus the temperature of air emitted into the bed. The fan  42  can be operated without energizing the heating element  50  to blow unheated room air into the bed  12 . An optional timer  58  may be provided to turn off the bed warmer  10  automatically after a defined period of time. Thus, the bed warmer shuts off even if the user falls asleep. The automated shutoff feature also prevents the bed from overheating in the event that the apparatus is left unattended. 
     When a person retires for the night, the bed warming apparatus  10  is activated for a few minutes prior to entering the bed. This blows heated air between the two sheets  32  and  34  warming the sleeping surfaces. When the person enters the bed, the air flows around the occupant. Specifically, the fan  42  drafts air from below the bed through the air inlet  36  into the housing  20  in which the air continues to flow through the aperture  44  in the inner wall  38  and into the passage  46 . It the heating element  50  is energized, the air flowing through the passage  46  is heated. The air continues to flow from the passage  46  through the outlet chamber  52  into the air deflector plenum  28 . The air exits the bed warming apparatus  10  through the air outlet  30  and flows between the sheets  32  and  34 , as indicated by arrows  56  in FIG.  2 . 
     With reference to FIG. 5, a second embodiment of an apparatus  100  is provided to warm a bed  112 , which has a conventional mattress  114  on top of a standard box spring  115 . The bed warming apparatus  100  includes an air distribution plenum  116  formed by a tube of plastic or similar material which extends across substantially the entire width of the mattress, preferably at the foot of the bed. If the person enters the bed from only one side, the air distribution plenum call be placed lengthwise along the opposite side. Attached to the air distribution plenum  116  are a pair of L-shaped supports  118 , each having a first leg  117  extending vertical downward from the plenum and a second leg  119  projecting horizontally from the first leg between the mattress  114  and box spring  115 . This engagement of the supports  118  between the mattress and box spring securely holds the air distribution plenum  116  on the bed  112  in a position in which the plenum extends slightly above the upper surface of the mattress  114 , as shown in FIGS. 6 and 7. 
     With continuing reference to FIG. 6, the air distribution plenum  116  has an inlet end  120  and a closed opposing end  121  with a plurality of outlet apertures  122 ,  123  and  124  spaced periodically between the two ends. The outlet apertures  122 - 24  increase in size going the inlet end  120  to the outlet end  121 . Specifically outlet apertures  122  nearest the inlet end  120  are smaller than the centrally located outlet apertures  123 , which in turn are smaller than the outlet apertures  124  that are even farther from the inlet end. The varying of size of the outlet apertures  122 - 24  balances the flow of air through the apertures so as to evenly distribute the air flow across the foot of the bed  112 . 
     As seen in FIG. 7, when the bed  112  is made up for sleeping, the supports  118  of the apparatus  100  extend between the mattress  114  and box spring  115 . A conventional sheet  126  is fitted tightly around the mattress  114  extending between the mattress and the air distribution plenum  116 . An upper sheet  128  is tucked between the upper surface of the box spring  115  and the supports  118 . The upper sheet  128  then wraps around the outside of the supports  118  and air distribution plenum  116  and is laid across the top of the mattress  114 . In this arrangement, the ail distribution plenum  116  is between the upper and lower sheets  128  and  126 . Note further that the projection of the air distribution plenum  116  above the upper surface of the mattress  114  creates a space between the two sheets  126  and  128  through which air is able to flow from the outlet apertures  118 - 20 . Additional bed covers, Such as a blanket, may be placed on top of the upper sheet  128 . 
     Referring once again to FIGS. 5 and 6, the inlet end  122  of the air distribution plenum  116  has an air flow diverter  130  connected thereto. The air flow diverter  130  is a hollow arcuate body which communicates with an opening at the inlet end  122  of the air distribution plenum  116 . The air flow diverter  130  curves around one corner of the mattress  114  and has an opposite end extending along the side of the mattress. A flexible air duct  132  is connected to check valve  133  at an opening in the bottom of the air flow diverter  130  at the end that is along side the mattress  114 . The flexible air duct  132  may be similar to those used in building HVAC systems or to the exhaust air from clothes dryers. The check valve  133  closes the opening into the air flow diverter  130  when air is not being forced through the flexible air duct  132 . This prevents cooler room air from entering between the bed covers when the bed warming apparatus  100  is not operating. The other end of the flexible duct  132  connects to a fan and heater unit  134  of the bed warming apparatus  1001  the air flow diverter  30  enables connection to the flexible air duct  132  to be made without interfering with the conventional manner in which the sheets and other bed coverings are tucked between the mattress and box spring at the foot of the bed. Specifically, that connection is along side the bed  112  where the bed covers merely fall vertically downward over the air flow diverter  130  and flexible air duct  132 . It should be understood that the air flow diverter  130  can be attached at the opposite end of the air distribution plenum  116  and the pattern of the outlet apertures  122 - 24  reversed. Furthermore, other variations of the present bed warming apparatus could have the inlet for the flexible air duct  132  located anywhere along the length of the air distribution plenum  116 . 
     Referring to FIG. 8, the fan and heater unit  134  has a housing  136  within which is mounted a fan  138  that blows air from the room through an electric heating coil  140  and air filter  142  into the flexible duct  132 . Any of several standard types of fans may be utilized. A conventional control circuit  144  governs the speed of the fan  138  and the temperature of the heating coil  140 . The operation of the control circuit  144  is controlled by a user input device  146  which enables the person using the bed to turn on and off the warning apparatus  100  and regulate the speed and temperature of the air flow. A thermostat (not shown) is provided at the outlet of the heating coil  140  to the control circuit to turn of the heating coil and prevent the unit  134  from overheating. An electric cord  148  supplies power to the fan and heating unit  134  from a standard 110 volt electrical outlet in the building. 
     A whistle  150  is provided in a chamber  154  between the heating coil  140  and the filter  142  and extends through an opening  152  in the housing  136 . When the filter  142  becomes sufficiently clogged so as to inhibit adequate air flow, air pressure builds up in the chamber  154 . The increase in pressure forces air through the whistle  150 , which thereby emits a sharp sound providing an audible indication of the need to replace or clean the air filter  142 . Access to the air filter  142  for servicing is accomplished by removing the cover of the housing  136 , as shown in FIG.  8 . 
     In applications of the present invention in which automatic control is not required, the particular blower and heater unit  134  shown in the drawings may be replaced by a conventional, portable hair dryer. In this case, the flexible air duct  132  is connected to the outlet of the portable hair dryer which function as the blower and heater unit 
     The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.