US3644710A

US3644710A - Electric surface heater assembly

Info

Publication number: US3644710A
Application number: US43828A
Authority: US
Inventors: Lester D Drugmand; Donald M Cunningham
Original assignee: Emerson Electric Co
Current assignee: Emerson Electric Co
Priority date: 1970-06-05
Filing date: 1970-06-05
Publication date: 1972-02-22
Anticipated expiration: 1989-02-22

Abstract

A support for a surface-type electric heating element for a stove top, including an adapter ring, a drip bowl and a spider, formed as a one-piece sheet-metal stamping, the surface element being adapted for plug-in connection with a terminal block, and having connection with the spider portion of the support to resist shifting of the surface element that otherwise might be effected by the thrusting force of the plug-in operation, and also to resist separation of the surface heater from its support.

Description

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Drugmand et al.

[54] ELECTRHC SURFACE HEATER ASSEMBLY [72] Inventors: Lester D. Drugmand; Donald M. Cunningham, both of Pittsburgh, Pa.

[73] Assignee: Emerson Electric Co., St. Louis, Mo.

[22] Filed: June 5, 1970 [21] Appl. No.: 43,828

[52] U.S. Cl ..219/463, 24/73 8, 219/461, 219/536 [51] Int. Cl ..H05b 3/68, l-l05b 3/06 [58] Field of Search ..2l9/458,463, 447,467, 461, 219/451, 455, 536-537; 24/73 B; 338/317; 174/40 CC [56] References Cited UNITED STATES PATENTS 3,482,079 12/1969 l-lurko ..219/463 2,667,564 1/1954 Cunningham ..219/463 [451 Feb. 22, 1972 3,506,805 4/1970 Sauder ..219/451 2,302,808 11/1942 Smith ..219/455 2,877,334 3/1959 McOrlly et al.. ....219/463 3,188,449 6/1965 Hanson ..219/455 2,248,224 7/1941 Fernberg. .....24/73 B X 1 2,849,600 8/1958 Harris ..24/73 B X 3,102,940 9/ 1963 Stone ..338/317 X Primary ExaminerVolodymyr Y. Mayewsky Attorney-Michael Williams 7] ABSTRACT A support for a surface-type electric heating element for a stove top, including an adapter ring, a drip bowl and a spider, formed as a one-piece sheet-metal stamping, the surface element being adapted for plug-in connection with a terminal block, and having connection with the spider portion of the support to resist shifting of the surface element that otherwise might be effected by the thrusting force of the plug-in operation, and also to resist separation of the surface heater from its support.

9 Claims, 7 Drawing Figures PATENTEDFEBZE m2 3,644,710.

SHEET 1 OF 2 1 NVENTORS LEbTER D. DRUGMAND DONALD M. CuNNmGHAM A TTORME y PAIENIEUFB22 I972 INVENTOR'S LESTER D. DRUGMAND DONALD M-CUNNWGHAM A TTOQNE Y ELECTRIC SURFACE HEATER ASSEMBLY BACKGROUND AND SUMMARY As far as we are aware, the electric heating industry produces, and the appliance industry uses, surface heaters generally corresponding to that shown in McOrlly, U.S. Pat. No. 2,877,334, in that the heating element is supported from the stove top by means of an adapter ring, a spider being formed separately and having connection with a marginal wall of the adapter ring, the heating element resting on top of the spider and having connection therewith, and a separate drip pan or bowl underlying the spider and heating element and depending from an annular flange formed on the adapter ring.

Thus, three separable parts formed the support for the surface heater and because these parts had to be produced separately and provisions made for their interconnection, the cost thereof was an item of concern. In the prior art construction, the spider was normally connected to the surface element and accompanied it, but the adapter ring and bowl, being separable items, frequently made assembly with each other and with the spider, a source of annoyance to the housewife. Further, storage and inventory control problems were considerable because of the separable parts.

Our invention eliminates the disadvantages above-noted and therefore the principal object of our invention is to provide new and improved electric heating elements of the aforesaid type.

DESCRIPTION OF THE DRAWINGS In the drawings accompanying this description and forming a part of this specification, there is shown, for purposes of illustration, an embodiment which our invention may assume, and in these drawings:

FIG. 1 is a top plan view of a surface heater assembly embodying our invention,

FIG. 2 is a fragmentary plan view of a detail,

FIG. 3 and 4 are sectional views corresponding, respectively, to the lines 3-3 and 4-4 of FIG. 1, the heating element being omitted in FIG. 4,

FIGS. 5 and 6 are fragmentary, enlarged sectional views, corresponding respectively, to the lines 5-5 and 66 of FIG. I, and

FIG. 7 is a perspective view illustrating a step in the assembly of the heating element with its support.

DESCRIPTION OF PREFERRED EMBODIMENT The electric heating element 10 herein disclosed is of customary construction, and includes a metal sheath 11 (see FIG. 3) in which a resistance wire 12 is disposed, the wire being electrically insulated from the sheath by highly compacted granular refractory 12. Preferably, the sheath is side-pressed to the generally triangular cross section shown.

The heating element 10 has its active heating portion formed as a flat spiral winding, and terminal portions l4--14 extend downwardly and forwardly. Terminal pins 15-15 are connected to opposite ends of the resistance wire and extend outwardly of the extremities of the terminal portions for plugin connection with contacts carried by a terminal block, such as in the manner shown in Cunningham U.S. Pat. No. 3,336,466.

A connector 16 extends crosswise of the terminal portions and corresponds to construction shown in Kozbelt U.S. Pat. No. 3,350,674. The connector 16 holds the terminal portions 14-14 in predetermined sideby-side relation to insure proper alignment with openings in the terminal block. Two bosses l7 and 18 extend from a face of the connector, and in accordance with construction shown in said Kozbelt patent, the boss 17 is separate from the connector and tightly crimped to the respective terminal portion 14, whereas the boss 18 is integral with the connector and also tightly crimped to the respective terminal portion. When the terminal portions and corresponding terminal pins are plugged into a terminal block, a reaction force is exerted on the terminal portions 14-14 in the direction of the arrows 19-19 seen in FIG. 1. Although the boss 17 is separate from the connector, it has a transverse size sufficient to abut the face of the connector 16.

It will be appreciated that our invention is not limited to plug-in use, but may be equally well used in construction shown in said McOrlly, U.S. Pat. No. 2,877,334, wherein the terminal block is connected to the terminal portions. In such case, the connector may be omitted.

Our invention provides a novel support for the coiled heating element, and such support includes an adapter ring portion 20, a bowl or drip pan portion 21 and a spider portion 22, all connected together. In the preferred embodiment, the support is made ofsheet metal and produced in quantity by a stamping operation.

The ring portion 20 is adapted to rest on the stove top 23 (see FIG. 3) and the bowl portion 21 is adapted to be disposed within the opening 24 in.the stove top. The ring portion has an annular wall 25 which is integrally joined with the bowl portion. Spaced parts of the bottom of the bowl portion are displaced upwardly to provide supports upon which the heating element rests.

In the disclosed embodiment, three spaced parts of the bottom of the bowl portion are displaced upwardly in the stamping operation to provide three equally spaced spokes 26 which extend from the center of the bowl portion 21 to the ring portion 20. As seen in FIGS. 5 and 6, each spoke is defined by spaced walls 27-27 integral with the bottom of the bowl portion and which incline upwardly toward each other to an integral upper connection 28, such upper connection lying in a plane which is at least level with the uppermost part of the ring portion 20.

At its center, the bowl portion has an upwardly displaced portion 29 which may carry indicia denoting the manufacturer, or the like, or a medallion may be connected to the portion 30. A shallow upwardly displaced portion 30 is diametrically opposite one of the spokes (spoke 26a) but is disposed along a line inclined to the diametric line, as seen in FIG. 1 and 7. The portion 30 is formed with an opening 31 through which the terminal portions 1414 are inserted, as suggested in FIG. 7, so that the terminal pins are disposed outside the bowl portion for plug-in purposes. The terminal portions are projected through the opening 31 and the heating element is then turned so that the spiral portion rests flatwise on the tops 28 of the spokes 26.

The spoke 26a is formed with spaced

openings

32, 33 in its top connecting surface 28, and convolutions of the spiral portion have depending members 34 which fit within the openings. Each member 34 is preferably a metal strip formed to provide a tapering central portion 35, and legs 36-36 which are projection welded to the undersurface of certain convolutions. Recesses 37 are formed at the junctions of the legs 36 with the central portion. The opening 32 is proportioned to closely but freely receive one of the members 34 (see FIG. 5) to hold the spiral portion against movement which otherwise would result when the element is plugged into the terminal block,

The opening 33 is elongated and its defining walls are lanced, as seen at 40, to provide springfingers. 41. As the member 34 is forced downwardly into the opening 33, its tapered formation will cam the ring fingers 41 apart and such fingers will snap into the recess 37 (see FIG. 6) to hold the spiral portion against separation from its support. The heating element and its support are normally in connected relation and may be handled as a unit. In the event the support is to be cleaned, the heating element may be easily removed therefrom by pulling upwardly on the spiral portion to remove the member 34 from its recess 33, twisting the element to the position suggested in FIG. 7, and separating the heating element and its support.

We claim:

1. An electric heater assembly, comprising a sheathed heating element having an active heating portion formed as a spiral winding and having terminal portions extending downwardly from said heating portion, and a sheet metal support formed in a stamping operation and having a ringlike portion and a bowl portion integral therewith and: extending downwardly therefrom, spaced parts of the bottom of said bowl portion being displaced upwardly to provide surfaces extending like spokes from the center of the bowl portion to said ringlike portion. each spoke being defined by spaced walls integral with said bowl portion bottom and inclining upwardly toward each other to an integral upper connection therebetween, one of said spokes having an opening in said upper connection, the upwardly inclining walls of said one spoke being lanced adjoining said opening to form spring fingers, and a member extending downwardly from said spiral winding and fitting within said opening, said member being wedge-shaped to spring apart said fingers as it enters said opening and has recesses into which said spring fingers snap to releasably lock said member within said opening.

2. An electric surface heater assembly, comprising a sheathed heating element having a flat active heating portion and terminal portions extending downwardly from said heating portion, and a unitary sheet metal member for directly supporting said heating element at the top of a stove, comprising a ringlike portion having a peripheral wall of a size greater than the periphery of said active heating portion and an integral bowl portion extending downwardly from said ringlike portion and underlying said active heating portion, and spaced ledges integral with said bowl portion and extending upwardly therefrom and upon which said active heating portion is detachably supported, thus providing a one-piece ring, bowl and element support which is easy to clean as a unit when said heating element is detached.

2. An electric surface heater assembly, comprising a sheathed heating element having a flat active heating portion formed as a spiral winding and having terminal portions extending downwardly from said heating portion, and a unitary sheet metal member for supporting said heating element at the top of a stove, comprising a ringlike portion circumscribing the periphery of said active heating portion and having an integral bowl portion extending downwardly from said ringlike portion and underlying said active heating portion, three spaced parts of the bottom of said bowl portion being deformed upwardly to form three ledges extending in spokelike manner from the central part of said bowl portion to a peripheral wall of said ringlike portion and upon which ledges said active heating portion is detachably supported, thus providing onepiece ring, bowl and spider support which is easy to clean as a unit when said heating element is detached.

4. The construction according to claim 3 wherein the central part of said bowl portion is deformed upwardly to form a medallion area, and wherein said spokelike ledges extend between said upwardly deformed central part and said ringlike portion.

5. The construction according to claim 3 wherein two connections are made between said active heating portion and one of said ledges, one connection being between the innermost convolution of said spiral wending and said one ledge and holding the innermost convolution against flatwise movement, and the other connection being between the outermost convolutions of said spiral winding and said one ledge and per mitting flatwise movement of said outermost convolution to accommodate for expansion and contraction caused by heating and cooling of said active portion.

6. An electric surface heater assembly, comprising a sheathed heating elementhaving a flat active heating portion formed as a spiral winding and having terminal portions extending downwardly from said heating portion. and a unitary sheet metal member for supporting said heating element directly from the top of a stove, comprising an adapter ring portion having an outer peripheral edge which is adapted to rest on that upper surface of the stove top which margins an opening in said top, and also having an inner peripheral wall adapted to be disposed within said stove top opening and ha ving an integral bowl portion extending downwardly from said ring rotation and underlying said bowl portion, spaced parts of the bottom of said bowl portion being deformed upwardly to form ledges upon which said active heating portion is detachably supported, thus providing a one-piece adapter ring, bowl and element support which is removable from the stove top and easy to clean as unit said heating element is detached.

7. The construction according to claim 6 wherein three spaced parts of the bottom of said bowl portion are deformed upwardly to form three ledges extending in spokelike manner from the central part of said bowl portion and upon which ledges said active heating portion is detachably supported.

8. The construction according to claim 7 wherein the central part of said bowl portion is upwardly deformed to form a medallion area, and wherein said spokelike ledges extend between said upwardly deformed central part and said inner peripheral wall of said adapter ring portion.

9. The construction according to claim 7 wherein two connections are made between said active heating portion and one of said ledges, one connection being between the innermost convolution of said spiral winding and said one ledge and holding the innermost convolution against flatwise movement, and the other connection being between the outermost convolution of said spiral winding and said one ledge and permitting flatwise movement of said outermost convolution to accommodate for expansion and contraction caused by heating and cooling of said active heating portion.

A5 UNI"E1) 5T1 TE iA'i'n'Nl ()n'r'nlin CERTIFICATE OF CORRECTIQN Patent No. 3 644 71.0 Dated 2/22/72 inventor(s) Lester D. Drugmand and Donald M., Cunningham It is certified that error appears in the above-identified patent and that said Lettere Patent: are hereby corrected as shown below:

Column 2, line 36, "30" should be- --29 v 1 Line 38, "FlG' 'l should be-- -FIGSZ- Line 62, "ling" should be--- -spri ng-5 Column 3, line 32 claim numbered as "2' should be I numbered as -3------, I I L I Column 4, line 6, "wending" should be ----.--winding---- Line 24, "'rOtatiOn' should be ----p rti Line 29, aftef "as" add- -a f- -and after "unit" add-" when Signed and sealed this 25th day of July 1972 (SEAL) I ,v

Attest:

ROBERT GOTTSCl-IALK Commissioner of Patents EDWARD I l.FLl3TCIlER,JR"-.- Attesting Officer 4 CERTIFICATE 0F CORRECTION Patent No.3 644 71.0 Dated 2 2g 72 Inventor(s) Lester D. Drugmand and Donald M, Cunningham It is certified that: error appears in the above-identified patent and that: said Letters Patent: are hereby corrected as shown below:

P. Q Column 2, line 36, "30" Should be--'- -29 Line 38, IG". should be -F1esf- Line 62; "ring" should be-- --i-springf Column 3, line 32, claim numbered as "2'Y. should be I numberedas -3 Column 4, line 6, "wending" should be --winding---- Line 24, "rotation"' should be --portion Line 29, after "as" add--a -and after "unit" add-" When Signed and sealed this 25th day of July 1972.

(SEAL) w Attest:

EDWARD M. FLETCIIERJR ROBERT GOTTSCHALK I Attesting Officer Commissioner of Patents

Claims

1. An electric heater assembly, comprising a sheathed heating element having an active heating portion formed as a spiral winding and having terminal portions extending downwardly from said heating portion, and a sheet metal support formed in a stamping operation and having a ringlike portion and a bowl portion integral therewith and extending downwardly therefrom, spaced parts of the bottom of said bowl portion being displaced upwardly to provide surfaces extending like spokes from the center of the bowl portion to said ringlike portion, each spoke being defined by spaced walls integral with said bowl portion bottom and inclining upwardly toward each other to an integral upper connection therebetween, one of said spokes having an opening in said upper connection, the upwardly inclining walls of said one spoke being lanced adjoining said opening to form spring fingers, and a member extending downwardly from said spiral winding and fitting within said opening, said member being wedgeshaped to spring apart said fingers as it enters said opening and has recesses into which said spring fingers snap to releasably lock said member within said opening.

2. An electric surface heater assembly, comprising a sheathed heating element having a flat active heating portion formed as a spiral winding and having terminal portions extending downwardly from said heating portion, and a unitary sheet metal member for supporting said heating element at the top of a stove, comprising a ringlike portion circumscribing the periphery of said active heating portion and having an integral bowl portion extending downwardly from said ringlike portion and underlying said active heating portion, three spaced parts of the bottom of said bowl portion being deformed upwardly to form three ledges extending in spokelike manner from the central part of said bowl portion to a peripheral wall of said ringlike portion and upon which ledges said active heating portion is detachably supported, thus providing one-piece ring, bowl and spider support which is easy to clean as a unit when said heating element is detached.

5. The construction according to claim 3 wherein two connections are made between said active heating portion and one of said ledges, one connection being between the innermost convolution of said spiral wending and said one ledge and holding the innermost convolution against flatwise movement, and the other connection being between the outermost convolutions of said spiral winding and said one ledge and permitting flatwise movement of said outermost convolution to accommodate for expansion and contraction caused by heating and cooling of said active portion.

6. An electric surface heater assembly, comprising a sheathed heating element having a flat active heating portion formed as a spiral winding and having terminal portions extending downwardly from said heating portion, and a unitary sheet metal member for supporting said heating element directly from the top of a stove, comprising an adapter ring portion having an outer peripheral edge which is adapted to rest on that upper surface of the stove top which margins an opening in said top, and also having an inner peripheral wall adapted to be disposed within said stove top opening and having an integral bowl portion extending downwardly from said ring rotation and underlying said bowl portion, spaced parts of the bottom of said bowl portion being deformed upwardly to form ledges upon which said active heating portion is detachably supported, thus providing a one-piece adapter ring, bowl and element support which is removable from the stove top and easy to clean as unit said heating element is detached.