US2804533A - Heater - Google Patents

Description

Aug. 27, 1957 M. NATHANSON HEATER Filed Feb. 27, 1956 n 0 15 Wm M m y J a.

ite States Patent 01 HEATER Max Nathanson, Montreal, Quebec, Canada Application February 27, 1956, Serial No. 567,917

3 Claims. (Cl. 219-34) This invention relates to heaters and particularly to heaters which can be adapted to a variety of uses such as for space heating or for the heating of solids or liquids or a combination thereof.

The invention consists essentially in embedding a heating element mat with suitable terminals between two insulating mats and subjecting the combined mats together with resin and a catalyst to pressure in a mould to form a homogeneous dished panel structure ready for use as a heater.

The object of the invention is to provide a one piece heater structure which can be used as a heating tray for solids or liquids or can be used as a space heater without conversion.

A further object of the invention is to provide a heater which, except for projecting terminal studs, is completely embedded in plastic of a suitable nature considering the end use which the heater is to be put to.

A further object of the invention is to provide a heater which can be immersed in washing water without harmful effects.

A further object of, the invention is to provide a heater element in which the heating wire is sewn by simple stitching which can be done in any sewing machine without special attachments.

A further object of the invention is to provide a heater which can be used as a container at times without detriment to its function as a heater.

These and other objects will be apparent from the following detailed specification and the accompanying drawings forming a part thereof, in which- Fig. 1 is a perspective view of the tray type heater.

Fig. 2 is a longitudinal sectional view of the basic sandwich comprising the heating element with its attached terminals and the insulating pads above and below.

Fig. 3 is a longitudinal sectional view of the moulded tray heater.

Fig. 4 is a plan view of the heating element showing the heating wire sewn to the base pad.

Fig. 5 is a section of the line 55 of Fig. 4.

Fig. 6 is an enlarged sectional view taken from the right hand end of Fig. 3 and showing the terminal stud embedded in the plastic structure of the tray heater.

Fig. 7 is a vertical sectional view of a tray heater converted into use as a space heater and mounted on a wall surface with suitable reflecting surfaces and trim.

Referring to the drawings, the heater tray 1 is formed from an element supporting mat 2 and top and bottom insulating mats 3 and 4 moulded into shape with a suitable resin and a catalyst, under pressure and under hot or cold conditions depending on the type of resin used and the finish required.

The element supporting mat 2 can be a sheet of glass paper or be a fibreglass mat and the conducting wire 5 is laid out on its surface in any desired pattern to give the length of wire required. The element supporting Patented Aug. 27, 1957 ice mat 2 is of smaller size than the insulating'mats 3 and 4 so that, when the mats are bonded together, the mats 3 and 4 will come together and seal around the edges of the mat 2. The width of the overlap edges being that amount required to form the sides and top flange of the finished tray. The wire 5 is held to the mat 2 by a heat resistant thread 6 sewn to the mat 2 in a zig-zag manner by a sewing machine. No special form of sewing stitch is required as then the heater tray is formed the conducting wire 5 is embedded in the structure and the thread 6'is then of no further use in holding the wire in place. The thread 6 can be of any suitable material such as cotton, nylon, glass or resistance wire depending upon the temperature it will be submitted to during the moulding operation. For instance cotton can be used with temperatures up to approximately 200 F., nylon up to 300 F., glass for above 300 F., and for very high temperatures, resistance wire would be used. It is essential that the thread 6 does not burn or discolour during the moulding operation as discolouration might show through to the surface of the finished tray and thereby spoil its finished appearance.

The conductor wire 5 has its terminals 7, 7 threaded through the lower insulating mat 4 and attached to the terminal studs 8.

The sandwich formed of the heating element mat 2 and the top and bottom insulating mats 3 and 4 are then placed in the bottom section 11 of a mould which has suitable cores to receive and support that portion of the terminal studs 8 which project into the recess 9 formed in the terminal socket block 10 in the finished heater tray. The desired quantity of resin and catalyst is then spread over the surface of the top insulating mat 3, and the top section 12 of the mould is then brought down in regular plastic moulding procedure under hot or cold conditions and with the required pressure to force the resin and catalyst completely through the sandwich to form a homogeneous heater tray in which the conductor Wire 5' and the terminal studs 8 are permanently embedded.

When the heater tray is thus formed the plastic impregnated sandwich holds the wire 5 to its pattern and the thread 6 no longer serves any useful purpose. It is for this reason that the thread and the method of sewing require only to withstand the temperature encountered during the moulding process to prevent burning of the thread. Therefore, for low temperature moulding a glass thread at most is all that is required but where high temperature moulding is used, a thread of resistance wire may be required.

If a pattern effect is required on the inner and outer surfaces of the heater tray 1 a patterned cloth 13 can be laid on the top surface of the mat 3 and below the mat 4. The patterned cloth will then be moulded solidly on the surfaces of the heater tray.

The tray 1 thus formed is, except for trimming around the edges, ready to be plugged into an electrical socket for immediate use in heating liquids or solids for cooking or for industrial use.

In the modification shown in Fig. 7 the heater tray 20 is manufactured in the same manner as the tray 1 described above except that its terminal block 21 is moulded in the inside surface of the tray and has its terminals 22 projecting clear of the block 21 to facilitate making the 1 connections 23 to the conduit box 24.

3 to deflect the hot air upwardly and outwardly away from the wall 26.

A reflector 29 can be mounted on the flanged wall panel 25 to reflect outwardly the heat from the tray 20 and to further protect the wall 26.

The heater above described has many applications either as a heater for fluids or solids or as a space heater. While the heater has been shown in the form of a tray container it could be reversed to rest on its flanges and be used as a hot plate. Again the heater could be made in any desired shape such as round and need not be flanged, or the flange could be formed in such a way that a lid or cover could be fitted to retain the Warmth of the contents of the tray without departing from the scope of the appended claims.

What I claim is:

1. A heater unit comprising a pair of insulating mats, an electrical heating pad of smaller area than said insulating mats, said heating pad being sandwiched centrally between said insulating mats, with the insulating mats contacting each other all around the heating pad, said heating pad consisting of an element supporting mat, a wire element sewn to the surface of said supporting mat, and having its terminal ends projecting beyond the said supporting mat and threaded through the lower of said insulating mats, terminal studs connected to the terminal ends of said wire element, a resin bonding material moulded with said insulating mats and heating pad to form a homogeneous tray type unit, and a resin moulded terminal box on and homogeneous with the said side of the tray, said terminal studs being located within said terminal box and accessible from the outside of the heater unit.

2. A heater unit comprising a pair of insulating mats, an electrical heating pad of smaller area than said insulating mats, said heating pad being sandwiched centrally between said insulating mats, with the facing surfaces of the insulating mats contacting each other all around the heating pad, said heating pad consisting of an element supporting mat, a wire element sewn to the surface of said supporting mat and having its terminal ends projecting beyond the said supporting mat and threaded through the lower of said insulating mats, terminal studs connected to the terminal ends of said wire element, a resin bonding material moulded with said insulating mats and heating pad to form a homogeneous flanged tray heater unit with the heating pad confined to the bottom surface thereof, and a resin moulded terminal box on the side of and homogeneous with the said tray and located under the flange thereof, said terminal studs being located within said terminal box and accessible from the outside of the heater unit.

3. A heater unit comprising a pair of insulating mats, an electrical heating pad of smaller area than said in sulating mats, said heating pad being sandwiched centrally between said insulating mats with the facing surfaces of the insulating mats contacting each other all around the heating pad, said heating pad consisting of an element supporting mat, a wire element sewn to the surface of said supporting mat and having its terminal ends projecting beyond the said supporting mat and threaded through the upper of said insulating mats, terminal studs connected to the terminal ends of said wire element, a resin bonding material moulded with said insulating mats and heating pad to form a homogeneous flanged tray type heater unit and a resin moulded terminal box on the inside surface of the heater unit and supporting said terminal studs, a flanged mounting panel secured within said tray and having its outer surface flush with the outer surface of the tray flange, and a reflector surface on the inner side of said flanged mounting panel and facing the bottom heating surface of the tray.

References Cited in the file of this patent UNITED STATES PATENTS 1,142,393 Bloomer June 8, 1915 2,119,680 Long June 7, 1938 2,458,184 Marick Ian. 4, 1949 2,540,295 Schreiber Feb. 6, 1951 2,553,974 Lamb May 22, 1951 2,572,163 Lamb Oct. 23, 1951 2,715,668 Booker et al. Aug. 16, 1955

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