Patent Publication Number: US-6220659-B1

Title: Heated stadium seat

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 09/072,478, filed May 4, 1998, which issued as U.S. Pat. No. 5,915,783 on Jun. 29, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to heated seats and more particularly to heated seats for use in an outdoor environment such as a stadium. 
     Various proposals have been made for heated seat designs for use in an outdoor stadium environment. However, none of these proposals have seen any significant commercial exploitation since each design suffers from one or more disadvantages. Specifically, the design is too expensive to install initially; the design is too expensive to operate; or the design is not rugged and durable enough to withstand prolonged exposure to the temperature and precipitation extremes encountered in an outdoor stadium environment. 
     SUMMARY OF THE INVENTION 
     This inventions is directed to the provision of an improved heated seat. 
     More specifically, this invention is directed to the provision of a heated seat that is especially suitable for use in an outdoor environment such as a stadium. 
     The heated seat of the invention is of the type including a seat cushion and a seat back. According to one feature of the invention, the seat cushion is hollow and defines a generally horizontally extending seating surface; a substrate member is positioned within the hollow of the cushion in generally horizontal disposition; a thin film heating element is positioned on the substrate member; and means are provided which are operative to transmit electrical energy from a location outside of the cushion to terminals of the thin film heating element. This basic arrangement provides a simple, efficient, waterproof, and durable heating construction for an outdoor seat. 
     According to further feature of the invention, the seat further includes expanded foam filling the hollow of the cushion in the region beneath the substrate member. The expanded foam serves to locate and fix the substrate member and further serves to discourage migration of heat downwardly from the heating element so as to concentrate the heat in an upward direction against the seating surface. 
     According to further feature of the invention, the cushion includes an opening proximate a rear edge of the cushion providing access to the hollow interior of the cushion; the substrate member and the thin film heating element comprise an insert; and the insert passes through the access opening in the rear edge of the cushion to position the thin film heating element in the hollow of the cushion beneath the horizontally extending seating surface. This insert arrangement facilitates the construction and assembly of the seat and preserves the waterproof aspect of the seat. 
     According to further feature of the invention, the insert further includes a handle member including a head trim portion positioned against an outer face of the rear edge of the seat and a neck portion extending forwardly from the head trim portion, passing through the access opening, and fixedly secured to a rear edge of the substrate member. The handle member thus facilitates the installation of the heating unit into the seat cushion without derogating the waterproof aspect of the seat. 
     According to a further feature of the invention, the seat cushion defines a rearwardly opening crevice within the hollow of the cushion proximate a front end of the cushion, and a forward edge of the substrate member is positioned in the crevice to define and fix the forward position of the substrate member. This coaction between the forward edge of the substrate member and the internally defined crevice further facilitates the installation of the heating assembly into the seat cushion. 
     According to a further feature of the invention, the seat back is hollow and a heating arrangement generally corresponding to the heating arrangement in the seat cushion is provided in the seat back. 
     The invention further provides a unique seating arrangement for a stadium. The seating arrangement of the invention comprises a plurality of seats arranged in rows and each including a seat cushion and a seat back; an elongated power lead extending proximate each row and passing proximate each seat in the row; a heating unit positioned in the seat cushion of each seat; a junction box electrically interposed in the power lead proximate each seat; and a detachable electrical connection proximate each seat detachably interconnecting the heating unit in each seat with the respective junction box. This arrangement provides a simple and effective means of selectively providing heating to a large plurality of seats in a stadium environment. In the disclosed embodiment of the invention, each detachable electrical connection comprises a lead extending from the respective junction box and terminating in an electrical lead plug and an electrical plug positioned in a rear edge of the respective seat cushion and sized to detachably receive the lead plug. 
     The invention further provides a method of providing a heated seat. According to the invention method, a seat cushion is formed as a hollow closed structure including an opening providing access to the hollow interior of the seat; a heater unit is formed including an electrical resistance element; the heater unit is inserted through the access opening and into the hollow of the seat cushion; and electrical energy is delivered to the electrical resistance element from a source of electrical energy located exteriorly of the seat cushion. This methodology provides a simple and efficient means of constructing a heatable seat cushion especially suitable for outdoor use. 
     According to the further feature of the invention methodology, the heating unit includes a substrate member and a thin film heating unit secured to an upper face of the substrate member and defining the electrical resistance element; the access opening is provided in a rear edge of the seat cushion; and the heating unit is inserted forwardly through the access opening to position the substrate member within the hollow of the seat cushion and position the thin film heating unit beneath the seating surface of the seat cushion. This specific methodology further facilitates the ready and efficient construction of a heatable seat especially suitable for outdoor use. 
     According to further feature of the invention, the seat cushion is formed as a plastic article in a blow molding operation and the method further includes delivering expandable foam material into the hollow of the seat beneath the substrate. The expandable foam serves to fix the substrate member and further serves to discourage emigration of heat downwardly from the heating unit so as to concentrate the delivery of heat from the heating unit upwardly to the seating surface. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary perspective view showing the installation of a heated seat assembly according to the invention in a stadium environment; 
     FIG. 2 is a cross-sectional view taken on line  2 — 2  of FIG. 1; 
     FIG. 3 is a cross-sectional view taken on line  3 — 3  of FIG. 2; 
     FIG. 4 is a perspective view of a heater insert assembly utilized in the invention seat assembly; 
     FIG. 5 is a perspective view showing the installation of the heater insert assembly in a seat cushion with the seat cushion shown in phantom; 
     FIG. 6 is a fragmentary cross-sectional view showing details of the mounting of the heater insert assembly in a seat cushion; 
     FIG. 7 is an end view of a seat cushion; 
     FIG. 8 is a plan view showing a plurality of heated seat assemblies according to the invention arranged in a stadium environment; 
     FIG. 9 is an exploded perspective view of a thin film heating element utilized in the heater insert assembly; 
     FIG. 10 is a detailed view taken within the circle  10  of FIG. 2; and 
     FIG. 11 is a fragmentary cross sectional view showing details of the mounting of a heater insert assembly in a seat back. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The heated seat assembly  10  according to the invention includes a seat cushion assembly  11 , a seat back assembly  14 , and a seat frame  60 . 
     Seat cushion assembly  11  includes a seat cushion  12  formed of a suitable plastic material in a blow molding operation and defining a closed hollow  12   a . Seat cushion  12  includes an upper wall  12   b  defining a generally horizontally extending seating surface  12   c ; a lower wall  12   d ; and a rear wall  12   e  including an access opening or slot  12   f . Lower wall  12   d  is kissed off at  12   g  to the confronting lower face of upper wall  12   b  to define the forward boundary of hollow  12   a  and define a front end portion  12   h  of the seat positioned forwardly of the kiss-off point  12   g.    
     Seat cushion assembly  11  further includes a heater unit  18  formed as a seat cushion insert. Heater insert  18  includes a substrate board  20 ; an etched thin film heating element  22 ; a handle member  24  of T-cross-sectional configuration and including a trim head portion  24   a  and a neck portion  24   b ; an electrical plug  26 ; and electrical leads  28   a ,  28   b  and  28   c.    
     Substrate board  20  may comprise, for example, an aluminum plate. 
     Thin film heating element  22 , as best seen in FIG. 9, has a sandwich construction including an upper thin layer of moisture impervious insulation material  30 , a lower thin layer of moisture impervious insulation material  32 , and an etched foil resistive element  34  sandwiched between the moisture impervious insulation layers and totally encapsulated by the moisture impervious layers to form a waterproof construction. Thin film heating elements of this general type are available, for example, from Minco Products, Inc. of Minneapolis, Minn. 
     In the assembled heater insert  18  a thin film heating element  22  is suitably adhesively secured to the upper face  28   a  of substrate board  20  proximate an intermediate portion  20   b  of the board; a rear edge portion  20   c  of the board is fixedly secured by mechanical fasteners  35  to the upper face of neck portion  24   b  of handle member  24 ; electrical plug  26  is positioned in a central aperture  24   c  in the head trim portion  24   a  of the handle member; leads  28   a  and  28   b  extend rearwardly from plug  26  beneath neck portion  24   b  and then pass upwardly through a grommet  36  in substrate board  20  for respective connection to the terminals  22   a ,  22   b  of thin film heating element  22 ; and lead  28   c  passes rearwardly from plug  26  and is suitably grounded to substrate board  20   a.    
     The resistive etched wire  22   c  of the thin film heating element extends in sinusoidal fashion through the heating element between terminals  22   a  and  22   b  and the thin film heating element further includes a thermostat  40  and a fuse  41  arranged in series with wire  22   c  and encapsulated in waterproof manner within moisture impervious layers  30  and  32 . Thermostat  40  may be set to turn on and off between a range of 120 and 130° F. so that the resistive heating element is maintained at a temperature between 120° and 130° F. and fuse  41  may be set to burn out at 150° F. so that the temperature of the resistive heating element will never rise above 150° F. even if the thermostat fails at its upper end. Insert  18  is inserted through access slot  12   f  in the rear edge  12   e  of the cushion whereafter the insert is moved forwardly to pass substrate  20  totally through the slot and into the hollow  12   a  of the cushion, pass the neck portion  24   b  of the handle member  24  through the slot, position the leading edge  20   d  of the substrate member in the crevice  140  defined at the kiss-off point  12   g  between the upper and lower walls  12   b  and  12   d  of the cushion, position the forward face  24   d  of the head trim portion  24   a  of the handle member in conforming abutment with the confronting surface of the rear edge portion  12   e  of the seat cushion, and position plug  26  in a central semi-circular cutout  12   i  forming a downward extension of access slot  12   f . Head trim portion  24   a  is adhesively secured to the rear edge  12   e  of the seat cushion and may if necessary be temporarily mechanically secured to allow the adhesive to set up. The adhesive is waterproof to define a waterproof seal at the interface of the head trim portion  24   a  and seat rear edge  12   e  to preserve the waterproof intensity of the seat. 
     After the insert  18  has been inserted as described into the seat cushion, expandable foam  42  is delivered into the hollow  12   a  beneath substrate member  20  via a fill hole  12   j  in the lower wall  12   d  of the cushion and allowed to expand in known manner to fill the hollow  12   a  beneath the substrate member. The expanded foam  42  may also, as seen in FIG. 3, extend upwardly somewhat beyond the level of the substrate member  20  along opposite edges of the substrate. Note in this regard that substrate  20  may be sized so as not to extend the full width between the side walls  12   k  of the cushion so as to leave room as shown for the expanded foam to bulge upwardly along the opposite sides of the substrate member. The fill hole  12   i  is plugged with a suitable sealed plug  24 . The expanded foam serves to position and fix substrate member  20  within the hollow of the seat cushion and further serves as heat insulation material to discourage downward migration of heat generated by heating element  22  and concentrate the heat upwardly against seating surface  12   c . Expandable foam  42  may, for example, comprise a water blown urethane foam which is blown under pressure into the hollow of the cushion in liquid form as a mixture of urethane foam material and reactant chemicals, whereafter the chemicals react to form bubbles which expand the foam to fill the hollow  12   a  beneath the substrate member. 
     Seat back assembly  14  is formed in a manner similar to the described manner of construction of the seat cushion assembly. Specifically, and as best seen in FIG. 11, a heating unit insert  50  is formed including a substrate member  52 ; a thin film heating element  54  corresponding to thin film heating element  22 ; a handle member  56  including a head trim portion  56   a  and a neck portion  56   b  mechanically secured as by fasteners  58  to the lower edge  52   a  of the substrate member; an electrical plug  60  positioned in head trim portion  56   a ; and a plurality of leads  62  extending upwardly from the plug and passing through a grommet  64  in the substrate member for suitable grounding on the substrate member and connection to the respective terminals of the thin film heating element  54 . Heating unit insert  50  is inserted upwardly through an access slot  66   a  in the bottom edge  66   b  of the hollow blow molded seat back  66  to position the upper edge  52   b  of the substrate member in the crevice  68  defined at the kiss-off  70  of the front and rear walls  66   b  and  66   c  of the seat back with the upper face  56   c  of the end trim portion  56   a  of the handle member cemented to the confronting face of the lower edge  66   b  of the seat back and plug  60  seated in a semi-circular cutout  66   b  formed as an extension of access slot  66   a . Expandable foam is thereafter delivered through a fill hole  66   e  in the rear wall  66   c  of the seat back to fill the hollow of the seat back rearwardly of substrate member  52  whereafter the fill hole  62   e  is plugged by a suitable plug  72 . It will be understood that seat back assembly  14  has a waterproof construction corresponding to the waterproof construction of seat cushion assembly  11 . 
     Seat frame  16  is formed of a suitable metallic material and includes spaced left and right frame members  74  each including an upright portion  74   a , an arm rest portion  74   b , and a mounting portion  74   c . In the completed seat assembly  10 , the seat back assembly  14  is fixedly mounted between spaced uprights  74   a , the seat cushion assembly is pivotally secured to the spaced arm rest portions  74   b , and the mounting portions  74   c  are utilized to mount the seat assembly in the chosen seat environment. 
     Seat assembly  10 , by virtue of its rugged and waterproof construction, is especially suitable for use in an outdoor environment such as a stadium  80  as seen in FIG.  8 . Specifically, a plurality of seat assemblies  10  are arranged in rows in the stadium with the frame mounting portions  74   a  of the seat frames secured to vertical riser surfaces  82   a  of a bleacher or grand stand  82  of the stadium and seat cushions  12  extending outwardly over horizontal run surfaces  82   b  of the bleacher or grand stand. 
     A junction box  84  is positioned against riser surface  82   a  immediately behind each seat assembly and an electrical power cord or lead  86  extends along each riser face and electrically interconnects the successive junction boxes so that the junction boxes are electrically interposed in the power lead  86 . 
     Each junction box includes a box  88 , a pigtail cord  90  terminating in a plug  92 , a pigtail cord  94  terminating in a plug  96 , and a switch  98 . 
     In the installed configuration of the seat assembly in a stadium, plug  92  is suitably inserted into plug  60  of the seat back assembly to provide electrical energy to the thin film heating element  54  of the seat back assembly and plug  90  is suitably connected to the plug  26  of the seat cushion assembly to provide electrical energy to the thin film heating element  22  of the seat cushion assembly. Power is selectively delivered to pigtail cords  90  and  94  from central power lead  86  by switch  98 . As seen in FIG. 8, a single lead  86  may extend in serpentine fashion through the entire stadium environment between a source  88  of electrical energy and a ground  90 , or a plurality of individual leads  86  may selectively supply individual rows of seats in the stadium. In either arrangement, it will be seen that power to all of the seats can be selectively controlled from the power source  88  and power to individual seats can be selectively controlled by the individual switch  98  in the individual junction box associated with the seat. The seat assembly may operate on  115  VAC line power or any other chosen power level. 
     The heated seat assembly will be seen to have many important advantages. Specifically, the assembly has a rugged, simple, and waterproof construction that lends itself to the harsh environments of an outdoor stadium. Further, the seat assembly lends itself to a low cost modular construction where the seat assembly inserts are manufactured and tested using mass production techniques and then inserted into the seat cushions. Further, the invention seat assembly is very efficient in its energy usage because of the inherent efficiency of the thin film heating elements employed and further by virtue of the action of the expanded foam positioned respectively beneath and behind the heater inserts and acting to preclude downward and rearward migration of heat generated at the inserts to concentrate the heat upwardly and forwardly against the respective seating surfaces. Further, the invention seat assembly lends itself to large scale stadium installations wherein a junction box may be readily provided in association with each seat cushion and each seat back and readily electrically connected to the cushion and back for heating as required. 
     Whereas a preferred embodiment of the invention has been illustrated and described in detail it will be apparent that various changes may be made in the disclosed embodiment without departing from the scope or spirit of the invention.