US 3013141 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Dec. 12, 1961 s 3,013,141
SEAT HEATER Filed Dec. 22, 1958 INVENTOR. LESLIE L. ELklS Ar'rogqay United States Patent 3,013,141 SEAT HEATER Leslie L. Ellis, 29650 Ryan Road, Warren, Mich. Filed Dec. 22, 1958, Ser. No. 782,151 1 Claim. (Cl. 219-46) This invention relates to heating pads and more particularly to a low voltage electric resistance heating pad.
It is the object of the present invention to provide a very simplified low voltage electric resistance heating pad which is particularly adapted for mounting upon the seat and backrest of a vehicle, and having lead wires terminating in a plug adapted for removable projection within the cigarette lighter receptacle. 7
It is another object to provide a simplified low voltage heating pad consisting of a felt strip with a continuous electric resistance wire circuitously extending over one surface thereof and nested down into the body of the strip defining a heating coil, together with means such as stitching or staples for securing the coil thereon.
It is another object to complete the heating pad by the application thereto of a covering envelope of suitable material, such as cotton, velveteen, wool or the like.
It is another object to provide a heating pad employing a plain electric resistance wire, which is circuitously laid down without coiling upon a resilient backing strip and secured thereto and wherein a low amperage, such as two to three amps, of current are utilized at a voltage of 6 to 12. volts direct current.
These and other objects will be seen from the following specification and claim in conjunction with the appended drawing in which:
FIG. 1 ,is a fragmentary schematic side elevational view of the present heating pad mounted upon the seat and connected to a vehicle dashboard.
FIG. 2 is a plan view, on an enlarged scale, of the present electric heating pad, partially broken away for illustration.
FIG. 3 is a fragmentary section on an enlarged scale taken on line 3-3 of FIG. 2.
FIG. 4 is a fragmentary section taken on line 4-4 of FIG. 2, on an enlarged scale.
FIG. 5 is a wiring diagram showing a use of a highlow switch for the heating pad.
"FIG. 6 is a side elevational view on an enlarged scale of one form of plug for the lead wires of the heating pad.
FIG. 7 is a fragmentary plan view illustrating the use of staples for securing the wire upon the felt strip.
FIG. 8 is a fragmentary section taken on line 8-8 of FIG. 7.
It will be understood that the above drawing illustrates merely a preferred embodiment of the invention and that other embodiments are contemplated within the scope of the claim hereafter set forth.
Referring to the drawing, the present heating pad shown in FIG. 2 includes a pair of rectangularly shaped resilient strips of material 11-12, preferably of felt. Parallel spaced straps 13 interconnect opposed spaced portions of the two strips and are secured thereto at points 14. These straps provide a hinge connection between said strips.
Individual heating coils 15-16 are mounted and secured respectively upon each of the strips 11-12. Each heating coil consists of a continuous electric resistance wire 17 circuitously mounted on and extending over the surface of the respective strips on one side thereof and nested and projected down into the body thereof. Accordingly, respective coils 15-16 lie entirely within the plane of strips 11-12.
Suitable means are employed, such as the continuous stitching 18, anchored in said strips looped over and ice throughout the length of the wire 17 for immovably securing said wires to the respective strips. Alternately as shown in FIGS. 7-8, the said wire 17 may be immovably secured in its embedded relation on strip 11 by a continuous series of wire staples 42' which retainingly overlie the top surface of wire 17 as at 44, FIG. 8, and whose free ends are bent inwardly against and into the bottom surface of the felt strip 11 as at 45.
Referring to FIG. 2, each of the coils 15-16 are substantially in the form of a double spiral with the respective ends of coil 15 terminating in the contact points 19-25 upon strip 11. The insulated lead wires 20-24 are respectively joined to contact points 19-25 and extend from said strip through the electrical oil and on switch 21 with actuator 22, and terminate in the plug 23 with end contact button 42, as shown on an enlarged scale in FIG. 6.
The respective free ends of second coil 16 on resilient strip 12 extend therefrom as at 17, FIG. 2, and are respectively joined to end portions of coil 15, as at points 26-27 respectively, in a parallel circuit relation.
Utilizing the present 12 volts direct current battery power source available in many vehicles today, the said coils 15-16 when plugged into the cigarette lighter receptacle 40 of a vehicle dashboard 41, as shown in FIG. 1, will use approximately 1.88 amps. per coil at 12 volts DC. or .94 amp. per coil at 6-volts D.C., thus demonstrating the very low power consumption of the present heating pad.
The respective pads 11-12 in the spaced relation shown are enclosed within a suitable fabric envelope 28-29, and the assembly is completed with the application thereto of the continuous beading 30 which is peripherally stitched at 31 along the edges of said envelope and secured to the respective adjacent edges of the strips 11-12.
Suitable goods or material are employed for this covering which would have some body such as cotton, velveteen, wool, or upholstering material. Spaced pairs of eyelets 32 are secured through the respective ends and intermediate portions of the assembled heating pad, providing means of securing said pad to seat 37 and backrest 35 of a vehicle seat, for example, employing fastening straps or tiedowns 36-38, FIG. 1.
Employing the heating pad in this fashion, the respective top and bottom portions 33 and 34 are arranged at approximately QO-degrees with respect to each other in view of the hinge connection 13, so as to cooperatively bear against said backrest and upon the seat.
The insulated lead wires generally indicated at 39, FIG. 1, corresponding to the individual lead wires 20-24, FIG. 2, terminate in the removable plug 23 which is manually projected into the cigarette lighter aperture 40. There is a second yielding contact 43 for said plug, FIG. 6 to establish suitable electrical connection to the lowvoltage D.C. power source, namely the vehicle storage battery.
FIG. 5 shows a slight variation of the electrical circuit shown in FIG. 2 and wherein heating coils 15-16, diagrammatically indicated, are connected to a conventional 12-volt DC. power source 46, and including a manually adjustable high-low switch for operating the heating coil in either a series or parallel circuit with said power source.
Lead 20 from said power source joins coil 15, which through lead 24, terminates in contact 47 engaging the movable shorting plate 48 on the manually movable switch armature 51. In the position shown in FIG. 5, said shorting plate engages contact 49 on lead 17 to coil 16 with the circuit back to the power source completed through lead wire 56 and normally open switch 22, when closed.
This provides a series circuit between said coils with a voltage drop of 6-volts over each coil so that each coil draws approximately 1 amp. This produces a constant and steady heating temperature for the pad of approximately 80 degrees F.
Armature 51 carries a pair of spaced contacts 4952 respectively connected with lead '53 to coil 16 and lead 54 back to power source 46. By manually shifting the armature 51 to the left from the position shown in FIG. 5, there is established a parallel circuit with a 12-volt drop over each of the coils 15-16.
The current flow would be through lead 20, coil 15, lead 24, contacts 47 and 52, and leads 53 and 50 back to power source 46. The circuit through the other coil is through lead 54, contacts 52 and 49, coil 16 and lead 50 back to the power source. Thiscorresponds to a higher heat wherein each coil draws approximately 2-amps. at 12-volts and produces a constant heating temperature of approximately 110 degrees F.
Off and on switch 21-22 from either of the circuits, FIGS. 2 and may be eliminated, if desired, with energization of the heating pad accomplished merely by introduction of plug 23 within cigarette lighter aperture 40 within the conventional vehicle dashboard 41 such as shown in FIG. 1. r While the illustrative preferred embodiment shows a preferred use for vehicles, it is contemplated that the present heating pad may be employed in any other environment desiring a low and inexpensive heat, as for example, an electric blanket or similar heating pad or for, use in chairs or couches.
It has been found that the present heating pad preferably operates on direct current electrical energy. However, it would be possible to utilize alternating current or employ a suitable rectifier therewith.
Having described my invention, reference should now be had to the following claim:
In an electric heating pad, a pair of spaced felt strips, a continuous electric resistance wire circuitously mounted on one side of and extending over the surface of each of said strips, respectively and nested down into the general plane of said strips, defining an individual heating coil for each strip, stitching on each strip looped over and securing said wires to said strips respectively, a pair of spaced straps interconnecting adjacent spaced portions of said strips, a fabric envelope enclosing said strips, insulated lead wires connected to and extending from the respective ends of one coil, and adapted for connection to a power source, and an electrical circuit including a high-low switch having a two-position longitudinally reciprocal armature, a shorting plate on said armature for connecting said coils in series with said power source when in one position for low heating, and spaced insulated contacts on said armature adapted to connect said coils in a parallel circuit with said power source for higher heating when longitudinally moved to a second position.
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