US 3769493 A
An electric immersion heater assembly for hot water heating boilers provided as a single phase circuit with a central conductive reinforcing rod that is utilized as one electrode and a ceramic body surrounding said rod with a resistance heating wire spirally wound upon said ceramic body and connected at its other end with a second electrode, said electrodes extending out of the heater at the unimmersed end and said immersed portion glazed with a non-conductive coating.
Description (OCR text may contain errors)
States Patent [191' Zeitlin et al.
[ 1 ELECTRIC IMMERSION HEATER ASSEMBLY  Inventors: Edward J. Zeitlin, Purdys; Lee
Leighton, Mohegan Lake, both of N.Y.
 Assignee: Edward J. Zeitlin, New York,
 Filed: Sept. 11, 1972  Appl. No.: 287,635
Related U.S. Applicatlon Data  Division of Ser. No 161,596, July 12, 1971, Pat. No.
52 user. ..219/33S,2l9/336 511 Km. Cl. H05b 1/00  Field at Search.....219/3153l6, 318, 320-321, 335-338, 523, 538 544, 546, 548; 338/267, 269-270, 275, 302-305, 311
 References Cited UNITED STATES PATENTS 1 1930 Smith 219 335 Oct. 30, 1973 2,096,635 10/1937 Goodwin 219/336 2,448,669 9/1948 Green, Jr.... 219/335 3,632,978 l/l972 Wrob 219/335 Primary Examiner-C. L. Albritton AttorneyHoward T. Jeandron  ABSTRACT An electric immersion heater assembly for hot water heating boilers provided as a single phase circuit with a central conductive reinforcing rod that is utilized as one electrode and a ceramic body surrounding said rod with a resistance heating wire spirally wound upon said ceramic body and connected at its other end with a second electrode, said electrodes extending out of the heater at the unimmersed end and said immersed portion glazed with a non-conductive coating.
4 Claims, 5 Drawing Figures PATENIEDHBI 30 ms ELECTRKC HMMERSION HEATER ASSEMBLY This application is adivision of the co-pending application, Ser. No. 161,596, filed July 12, 1971, now US. Pat. No. 3,707,618.
This invention relates to an electric immersion heater assembly and more particularly to an electric heater resistance element that is spirally wound upon a nonconductive rod, said rod having a conductive center that also reinforces the extended length of said rod, said rod glazed to be waterproof for insertion into a hot water heating boiler, said rod mountable through an opening in said boiler end plate and clamped to said boiler end plate to retain said electric immersion heater assembly in an operative, sealed position in said boiler.
In use in the trade, heaters of this type are generally comprised of a central non-conductive core with the heating filament or resistance wire wrapped around the core and the completely wound heater extending to be immersed in the fluid of the tank for heating the water. Due to the length of the heater and the material (generally a vitreous non-conductor such as porcelain), there is a danger of the supporting core cracking or actually breaking under extreme stress. The boilers in which these heaters are mounted are shipped, generally by truck, to the job for installation. Many of them are handled roughtly or dropped. This results in broken cores and defective heaters.
It is an object of this invention to provide an electric immersion heater assembly that is reinforced along its entire length to insure sufficient strength to the supporting core and prevent cracking or actual breaking of the unit after it is mounted in a boiler or tank.
It is a further object of this invention to provide a single phase electric immersion heater assembly comprised of a central steel reinforcing rod for strength, to which a ceramic covering is applied and a resistance wire heating element is spirally wound on the surface of said non-conductive covering and a protective vitreous glaze applied to completely cover said unit and make same completely waterproof so that the unit may be immersed in a tank of liquid as the means of heating said liquid.
1 Other objects of this invention shall be apparent by reference to the accompanying detailed description and drawings in which FIG. l is a side elevational view of a boiler or tank,
FIG. 2 is an end view of said boiler or tank,
MG. 3 is a side view (partially in cross section) of a single phase electric immersion heater assembly shown in a mounted relationship,
FIG. 4 is an end view taken on line 44 of FIG. 3,
FIG. 5 is a cross sectional view (slightly enlarged) taken on line 5-5 of HG. 3.
Referring to FlGS. 1 and 2 there is illustrated a typical boiler or tank for water or other fluids. FIG. 1 illustrates an elevational view of a round tank which is one embodiment. Other shapes of tanks may be similarly used. FIG. 2 illustrates an end view showing the boiler or tank end plate 11. With the heating of liquids in tanks of this type, the end plate is generally formed with circular apertures 12 to permit the insertion of electrical immersion heaters 14. The number of apertures 12 may vary according to the demands of the hot water or liquid desired. This invention is primarily concerned with the design and construction of the electrical immersion heater to be installed in the apertures 12.
Referring to FIG. 3 there is illustrated a cross sec- .tional view of a single phase electrical immersion heater to be utilized in conjunction with tank 10 as illustrated in FIGS. 1 and 2. The immersion heater 14 is of an elongated shape and generally circular in form so that the elongated heater 14 may be affixed to the boiler or tank plate 11 and extend through aperture 12 protruding as far as advisable to produce a distributed heating affect on the liquid contents of the boiler or tank. Due to the elongated structure of the heater and du e'to the non-conducting materials generally utilized, there is a weakness in the structural support and many of the heaters break or are damaged because of rough handling. In this embodiment the immersion heater 14 is provided with two metal reinforcing rods 15 that extend the full length of the heater to provide strength to the elongated non-conducting body 16. The body portion 16 is generally round in cross section and on opposed sides there are formed deep grooves 16A into which rods 15 are inserted. A non-conductive filler is added to cover each rod in its groove (if the body portion is ceramic, a similar filler of ceramic is used). The finished body with rods 15 inserted will be round in cross section. The ceramic body 16 at one end is, at the same time, formed into an enlarged mounting end which, in this embodiment, appears as a hexagonal shape 17. A further extension of the same ceramic body 16 protrudes from the hexagonal 'form as a circular extension 18. To insure a perfect seal when the element is mounted through an aperture 12, a sealing washer l9, rubber or otherwise, is positioned between the portion-l7 and the face of the end plate 11. A clamp 20 in the form of a plate with a central aperture 21 is fitted over the portion 17. The plate 20 is provided with apertures for a plurality of bolts 22 to pass through. The bolts 22 are mounted through the end plate 11 and welded to the end plate as shown in FIG. 3. Thus with the bolts extending to pass through plate 20, washers and nuts may be affixed to the bolts to draw the end plate 20 into a tight fitting relationship with the ceramic body portion 17 retaining it in a squeezed sealed position against the end plate 11. The immersion heater 14 also comprises a spirally wound heater resistance wire 24 wound upon the ceramic body 16 as illustrated in FIG. 3. The heater resistance wire 24 is connected at one end to one of the rods 15 and rod 15 in turn is connected to a terminal 25 that extends from the ceramic portion 18 to protrude as one electrode for the heater. The opposite end of the heater resistance wire 24 is connected at the opposite end of the ceramic body 16 to the end of the other metal reinforcing rod 15 preferably with a drilled insert in the rod and a permanently welded connection. Thus the conductive rod at its opposite end is provided with a welded terminal 26 that also extends from the ceramic body to become the other electrode of the heater element. To insure the protection of the heater element 24 in use, the entire external surface of the ceramic body and resistance wire that is mounted within the tank is glazed with protective vitreous glaze 27. Thus it is apparent that the electric immersion heater as constructed and as illustrated in FIG, 3 will provide a replaceable type mounting for easy removal or insertion of a new element and will provide a tight seal with the end plate of the boiler and will provide a practically indestructible projecting heater within the boiler.
Referring to FIG. 5 there is illustrated a cross sectional view taken on FIG. 3 illustrating the ceramic body 16 with the electrodes properly separated within the body 16 and the heater resistance wire 24 wrapped aroundthe body 16 and the protective vitreous glaze 27 covering the entire body.
Referring to FIG. 3 we may trace the connection of the rods 15 and the heating element 24. The pwer line is connected at 25 and 26 to rods 15. The heat element 24 is connected at one end to one of the rods 15 at the far end of the body, and to the other rod 15 through the ceramic body as illustrated in FIG. 3. Thus the complete element, that is, the body 16 and the resistance heating elements are coated with a protective vitreous glaze 27 Thus it is apparent that the electric immersion heater as constructed and as illustrated in FIGS. 3 and 5 will provide a replaceable type mounting for easy removal or insertion of a new element and will provide a tight seal with the end of a boiler and will provide a practically indestructible projecting immersion heater for the boiler. 1
Although we have shown a typical construction of a single phase electric immersion heater and its mounting and the manner of clamping or retaining the heater in a tight fitting sealed relationship with the boiler end plate, and electrodes to form a reinforced core, the
- shape of electrodes may vary without departing from the spirit of this invention and the particular form or pattern of the heating element may vary as long as the reinforced central core is retained to provide the desired indestructible form of heater.
The invention described in detail in the foregoing specification is subject to changes and modifications without departing from the principle and spirit thereof. The terminology used is for purposes of description and not of limitation; the scope of the invention being defined in the claims.
What is claimed is:
1. An electric immersion type heater comprised of spaced central reinforcing rods that are conductive, a ceramic tubular shaped covering body that is bonded to said central rods to form the immersion end of said heater and said ceramic tubular shaped covering body having one end enlarged to form the exterior end of said body for mounting, an elongated heating resistance wire wound upon the surface of said ceramic body, said heating resistance wire conductively connected at each end to the central rods, one connection at the immersion end and the other connection at the opposite end to provide electrodes that extend through said body for a circuit connection and said heating resistance wires extending through said enlarged end of said ceramic covering body to be conductively connected to a power source, said electrodes separated and protruding at the exterior end, said complete immersion surface of said tubular shaped covering body having a fluid-proof non-conductive coating.
2. An electric immersion-type heater according to claim 1 in which the exterior enlarged end of said ceramic body is hexagonal and a third portion of lesser radius protrudes on the exterior end to retain both electrodes.
3. In an immersion-type heater according to claim 2 in which there is a clamping plate with a central aperture to fit over said third portion and a plurality of bolts affixed to a boiler, means to clamp said immersion-type heater in a tight fitting relatinship to said boiler.
4. An electric immersion-type heater according to claim 1 in which the ceramic tubular shaped body is cast about said central rods to form an extended body capable of resisting cracking or breaking along the length of said body.