US3042785A

US3042785A - Electric heating unit

Info

Publication number: US3042785A
Application number: US17734A
Authority: US
Inventors: Leroy C Hanson
Original assignee: Ferro Corp
Current assignee: Vibrantz Corp
Priority date: 1960-03-24
Filing date: 1960-03-24
Publication date: 1962-07-03
Anticipated expiration: 1979-07-03

Description

July 3, 1962 c. HANSON ELECTRIC HEATING UNIT 2 Sheets-Sheet 1 Original Filed May 28, 1957 @w mg kg QM mgwmww DEN EN INVENTOR. fiery C [222223012 BY W July 3, 1962 Y L. c. HAN-SON ELECTRIC HEATING UNIT 2 Sheets-Sheet 2 Original Filed May 28, 1951 w fl MW R. Rm m m0 a e E w -a- 5 M a i C m m i MM United States Patent 3,042,785 ELECTRIC HEATING UNIT Leroy C. Hanson, Elmhurst, Ill., assignor to Ferro Corporation, Cleveland, Ohio, a corporation of Ohio Continuation of application Ser. No. 662,041, May 28, 1957. This application Mar. 24, 1960, Ser. No. 17,734 11 Claims. (Cl. 219-37) This invention relates to tubular. sheathed electrical heating units of the type adapted for range surface heating and has reference more particularly to the facilities by which the tubular sheathed elements thereof are mounted in the range top and the terminals thereof protected. This case is a continuation of application No. 662,041, now abandoned.

In such heating units the tubular sheathed elements thereof are usually arranged in the form of a flat winding which is set in an opening of the range cooking top or in the opening of a mounting ring with the top face of the winding elevated slightly above the surrounding surface so that a cooking utensil will rest directly on the winding, and it is customary to provide a pan underneath the winding which serves not only to collect spillage but also as a reflector to direct heat upwardly to the bottom of the pan or utensil on the winding. This pan or reflector may be made as a part of the range top or of the mounting ring but generally is a separate part which may be removed for cleaning.

Various expedients have been employed to permit access to the pan and the underside of the heating unit for cleaning thereof, the heating unit being sometimes arranged for complete removal for this purpose, but generally it is preferred tohinge the heating unit at one side of'the opening of the range top or ring so that it tilts to an upraised position at one side of the range top or ring opening to permit convenient access for cleaning or removal of the pan and for cleaning the underside of the heating unit itself.

In such heating units the end portions of the tubular sheathed elements of the winding are usually bent downwardly to a suitable level below the plane of the winding and extended outwardly through the side wall 'of the ring or pan so that they terminate at a protected place underneath the range top for connection of current sup- 'ply conductors to terminal wires which project from the ends of the tubular sheathed elements, and it' is important that the place of connection of the current suppyl conductors with these terminal wires be arranged so as to be safeguarded against access of spillage or grease thereto as such spillage or grease at the terminal ends may cause current leakage or shorts to occur at the terminals or it may even migrate into the end of the tubularsheath and cause current leakage or shorts therein.

In some of the expedients for permitting access to the pan and to the underside of the heating unit, one or more ends of the sheath ends have been arranged somewhat tangentially to serve as a hinge pintle and a positive hinging thus provided close to the side of the opening in which the heating unit is mounted, but many heating units are made with the sheath ends projecting sub,- stantially radially outward at one side of the opening to a place underneath the range top and difficulty has been experienced in providing a satisfactory hinging thereof. In some cases a loose connection has been provided whereby the heating unit may be manipulated by a combined sliding and tilting movement to the upraised position, andtin other cases a hinging has been provided underneath the range top and close thereto with extended specially shaped angular arms to provide necessary clearance thereof from the overlying margin of the opening,

3,042,785. Patented July 3, 1962 and downturned flange which is usually provided around the opening in which the heating unit is located.

In accordance with the present invention the heating unit is positively hinged in a simple and convenient manner at the periphery of the flange around the opening so that it swings up readily to upraised position without necessitating long specially shaped angular arms for required clearance, and the outwardly projecting sheath ends are also arranged to safeguard the exposed terminal wires and terminal connections against access of spillage or grease thereto which might cause current leakage or shorts.

The principal objects of the invention are to provide an improved hinging of heating units of the type in which the sheath ends project substantially radially outward; to construct the winding or coil supporting spider for simple and convenient hinging of the unit; to insure adequate protection of the terminal ends and connections from spillage and grease; and in general to provide an improved and simplified surface heating unit assembly, these and other objects being accomplished as pointed out more particularly hereinafter and as shown in the accompanying drawings, in which:

FIG. 1 is a plan view of a heating unit assembly embodying the features of the invention;

FIG. 2 is a vertical sectional view taken substantially along line 22 of FIG. 1 and illustrating the heating unit in position in the cooking top of an electric stove, and showing in broken lines the upraised position of the heating unit and in dotted lines the location of the sheath ends which lead from the inner ends of the coils of the winding.

FIG. 3 is a vertical sectional view through the terminal block, the View being taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is a fragmentary plan section taken substantially along the line 44 of FIG. 2 and showing the hinging means and the yielding detent means;

FIG. 5 is an enlarged fragmentary vertical sectional view taken substantially along line 55 of FIG. 4 and showing the hinge and detent means in the relation that they occupy when the heating element is in its horizontal position of use;

FIG. 6 is a view similar to FIG. 4 showing the hinge and detent means in the relationship that is occupied when theheatin'g element is in its raised or open position;

FIG. 7 is a fragmental portion of FIG. 2 showing the bearing arrangement employed in pivotally mounting the heating element;

' FIG. 8 is a fragmentary vertical sectional View taken substantially along the line 88 of FIG. 1;

FIG. 9 is a fragmentary vertical sectional view taken substantially along the line 99 of FIG. 8;

FIG. 10 is'a bottom plan view of the central portion of the spider upon which the heating element is carried, and

FIG. 11 is a fragmentary vertical sectional view taken substantially along line 1111 of FIG. 1. 'For purposes of disclosure the invention is illustrated herein as embodied in a heating unit and mounting ring assembly 20 that is adapted to be mounted in an opening 21 in the cooking top 22 of an electric range as indicated in FIG. 2 of the drawings. The assembly 20* comprises a mounting ring 23 having a supporting spider member 24 pivoted or hinged at one edge thereof a 27, and arranged to carry spirally coiled heating unit means 25 that has the terminal ends 26 thereof associated with. a terminal block 28, there being a heat reflecting and spillage collecting-pan 29 supported in the mounting ring 23 in a position beneath the spider 24 and the heating means 25.

The mounting ring 23 has a generally horizontal anspa-ares nular flange 23H that curves downwardly at its outer edge so that such outer edge may rest upon the cooking top 22 as shown in FIG. 2, and at the inner edge of the horizontal flange 23H, a downwardly extending substantially vertical annular wall 23V is formed, the lower end of which has a narrow inwardly extended horizontal support flange 23F. The lower supporting flange 23!? serves to support the pan 29 which, as shown in FIG. 2, has an annular flange or rim 29H that rests upon the horizontal flange 23F of the mounting r ng. The pan 29 is relatively deep, and has a sloping or conical surrounding wall, for reasons explained hereinafter, and, as shown in FIG. 2, an inward embossure 29B is provided at what may be termed the forward portion of the surrounding wall of pan 29 for finger engagement to facilitate lifting and removal of the pan 29 when this is desired. At its rear side the pan 29 has a clearance opening 29C formed therein, this clearance opening *bemg in the nature of a wide notch that extends to the upper edge of the pan, and provides clearance through which the terminal ends 26 of the heating means 25 may extend, and within which such terminal ends may move when the heating element is pivoted to its elevated position as indicated by the broken lines in FIG. 2 and as described hereinafter.

The spider 24 is formed from a pair of sheet metal strips that have corresponding portions 24W between their ends fastened together by rivets 31 or in any other convenient manner, and at one end of the portions 24W, the sheet metal members are bent to a diverging relationship to provide forward arms 24F, while at the other or rear end of the portions 24W the sheet metal members are bent in a diverging relationship to provide d1- verging rear arms 24R. The

arms

24F and 24R are of such. a length that the ends thereof may be located over the flange 23H so as to be supported thereon, 1t being noted however, that such support is in most 1nstances obtained by resting on the flange 29H of the pan 29 as will be evident in FIG. 2 of the drawings. At their outermost ends, the rear arms 24R of the spider have integral extensions providing connector arms 24C that are bent so as to extend generally toward each other as shown in. FIG. 1. At the inner ends of the connector arms 24C, the sheet metal strips are bent into a spaced parallel relationship so as to extend rearwardly and provide hinge arms 24H. The hinge arms 24H provide a portion of the hinge means whereby the spider 24 is'pivota-lly hinged to the mounting ring 23, and in providing this hinged relationship, the hinged arms 24H extend through spaced vertical slots 33 that are formed in the vertical flange 23V of the mounting ring. These slots have their opposite edges offset in opposite directions as shown in FIGS. 4 to 7 to provide opposed arcuate bearing seats 338 to receive and support the ends of a hinge pin 34. The hinge pin 34 extends at its oppos1te ends through pivot openings in the hinge arms 241-1, and the hinge pin is supported therebeyond in the bearing seats 338 as will be evident in FIGS. 4 to 7. The arms 24H are cut back at the top as indicated at 68 to provide clearance permitting the heating unit to be tilted to a highly upraised position.

The spider 24 may thus be pivoted from a horizontal position of use to a raised or open position, and means are provided whereby the spider is yieldingly maintained in its horizontal position or in its generally upright or open position. Such yieldingly retaining means are provided on the outer face of the rear portion of the flange 23V, as shown particularly in FIGS. 2 and 4 to 6. Thus, in the portion of the vertical flange 23V that is located between the slots 33 and elongated flat spring 35 is mounted so as to extend at its opposite ends into a cooperating relationship with respect .to the hinge arms 241-1. The spring 35 is held in position by a relatively heavy clamping strip 36 that is disposed on the outer or rear face of the strip 36 and the spring 35 in position.

4 The plate 36 terminates in spaced relationship with respect to the ends of the flat spring 35, and these projecting ends of the spring 35 are arranged to bear yieldingly against projecting pointed ends 24E of the hinge arms 24H. The pointed ends 24B are provided by angularly related surfaces 248, and when the spider 24 is in its horizontal position, the ends of the spring 35 bear against the pointed ends 24E at an elevation above the pivotal axis of the arms 24H, thus to exert yielding forces on the arms 24H tending to maintain the spider 24 in its horizontal position as shown in FIG. 5 of the drawing; When the spider 24 is swung to its upraised position the ends of the spring 35 bear against the pointed ends 24E at an elevation below the pivotal axis of the arms 24H and thus exert a yielding force to hold the spider in the upraised position as shown in FIG. 6.

The heating means 25, as illustrated herein, is made up of two elongated sheath type electrical heating elements 25E that are wound in a double fiat spiral as Will be evident in FIG. 1 with the coils of the elements 25E intercalated, and in the relatively large central space within the spirals, an escutcheon plate P is mounted on the spider '24. The plate P has downward edge flanges 38 that are anchored in slots 388 in the arms 24F and MR of the spider 24. As shown in FIG. 10, the flange 38 is slightly bent at 38B at several points to engage the sides of the arms of the spider and thus prevent rotative displacement of the plate P.

The heating elements expand and contract in the heating and cooling thereof, and because of the spiral form, a slight radial expansion and contraction of the coils occurs, and it is important that the spiral elements be suitably mounted so that they are free to expand and contract in accordance with temperature changes. 7

To this end, only the outer coil of each element 25B is attached to the spider 24 and only at places remote from the hinge H and the terminal ends 26. Thus the outer coil of each element 25 is secured to the forward arms 24F only of the spider as shown in FIGS. 1 and 2'.

For this purpose of securing these outer coils to the spider arms 24F, wire fasteners 39 of inverted L-shape are employed having short upper arms 39A substantially paralleling the coils and welded to the underside thereof and having the legs 39B thereof welded near their lower ends to embossments 40 pressed from the spider arms 24F all as shown particularly in FIGS. 8 and 9.

The coil of the heating unit is fastened to the spider arm in a position in which it rests on the upper edge of the spider arm, and the spider arms 24F are of such flexibility that, although the heating elements 25E are securely attached to the spider 24, such increase and decrease in length of the coil between the two places of fastening thereof which occurs on account of tempera-.

ture changes, is readily accommodated by the flexibility of the arms 24F, and any change in arcuity of the coil portion is accommodated by permissible twist of the wire of the inverted L-shaped wire fasteners 39.

As will be evident in FIG. 1, the heating elements 25B are wound in a double spiral and at the outer ends of the spirals are bent downwardly as at 60 and are then bent outwardly at 61 to provide the relatively short terminal portions 26 as shown in FIGS. 1 and 2 and at the inner ends of the spirals the heating elements 25E are likewise bent downwardly as at 62 and then outwardly as at 63 to provide the relating long terminal portions 26 as shown in FIG. 1 and by dotted lines in FIG. 2.

The downwardly extending

portions

60 and 62 are so related that the several terminal portions 26 may extend parallel to each other beneath the hinge H and toward the terminal block .28, and it is an important feature heating unit and accordingly the resistances 65 of the heating elements 25E, in accordance with conventional practice, extend to or into the

downturned portions

60 and 62 where they are electrically connected to low re-' sistance terminal conductors which extend therefrom out through the bends 61 and 63 and through the terminal portions and project from the sheath ends, as indicated at 2ST for attachment of current supply conductors thereto. These low resistance terminal conductors are located centrally within the sheaths 64 and embedded, like the resistances 65, in compacted insulation 66 which may terminate a sufficient distancefrom the sheath ends to accommodate high temperature resistant plugs 67 of a material, such as silicone rubber, which closely encircle the wires 25T and fit snugly within the sheath ends to seal the latter.

The terminal portions 26 extend an equal distanceoutwardly under the range top '22 so asto terminate at a place where they are safely protected against spillage from cooking operations on the heating unit, and their outer ends are arranged to extend into pockets of the terminal block 28 in which provision is made for connection of current supply wiresto the exposed projecting ends 2ST of the terminal conductors.

This terminal block 28 is of ceramic material and is formed with a bottom wall 28B, the upper face of which is stepped as at 68, and having side walls 288 and intermediate walls ZSD- extending upwardly from the bottom wall and all extending forwardly from a relatively thick rear or outer end wall 28R having openings 45 therethrough.

Between the two intermediate walls 28D and between one of these walls 28D and one of the side walls 288, two small pockets are formed to accommodate respectively therein terminal clips 41 and 42, and between one of said walls 28D and the other side wall 285 a large pocket is formed to accommodate a large common terminal clip 43 therein, and each of said pockets has one of the openings 45 leading therefrom through the rear or outer end wall 28R. The terminal clips 41 and 42 are associated respectively with the corresponding long ends 26 of the 'two heating elements 25E which have the projecting terminal wires 25T'thereof welded to the respective clips 41 and42 as will be evident in FIGS. 1 and 3 of thedrawings. Each of theclips has a terminal screw 42S whereby a line wire may be connected to the terminal clip.

The other terminal clip 43 constitutes the. common terminal for the two heating elements 25E as will be evident in FIG. 1 of the drawings, and the clip 43 is therefore connected to both of the terminal wires 2ST of the other short ends 26 of the heating elements 25E.' Three line wires 69 are shown and each extends through a respective one of the openings 45 through the rear. wall 28R. The several terminal clips are located in the pockets of the terminal block 28, withthe screws 42S'there'of over clearance pockets 44 formed in the bottom wall 28B and the inner end of the bottom Wall 28E of the terminal block is arranged to underlie and bear against the outer ends of the terminal portions 26 of the heating element.

For holding the terminal block 28 on the outer ends of the terminal portions 26 and protecting the terminal block and terminal connections against greaseand spillage, two inner end cover plates 48 of sheet metal are provided at the inner end of the terminal block and which conjointly extend substantially entirely acrossthe inner end of the terrninalblock.

These plates 48 are alike, except as hereinafter noted, and one, which is identified by the reference character 48A, is secured to the outer ends of the short terminal portions 26 which lead from the outer coils respectively of the spiral windings of the two heating elements 25E and the other, which is indicated by the reference character 48B, is'secured to the outer ends ofv the long terminal portions 26 which lead from the inner coils respectively of the spiral windings of the two heating elements 25E.

In the expansion and contraction of the heating elements under the changes of temperature to which they are subjected, the coils thereof tend to expand and contract and by reason thereof the terminal portions 26 at the opposite ends of each element 25E tend to move toward and away from one another and as the corresponding ends of each heating element 25E tend to move similarly in this manner the two short terminal portions 26 which are connected to the plate 48A tend to move similarly toward and away from the long terminal portions 26 which are connected to the plate 48B and thus by employing

separate plates

48A and 48B expansion and contraction of the coils is accommodated and each element 25E is free to expand and contract.

Moreover the pockets in which the terminal clips 41, 42 and 43 are located are of suiiiciently greater width than the clips located therein so that these clips are free to move sidewise in their pockets to permit freedom of expansion and contraction of the coils of the elements 25E. j

The plates 48 are located quite close to one another, substantially as shown in FIG. 1, when the heating ele ments 25E are at normal room temperature and separate to some extent when the heating elements 25B are ener- 'gized, and the terminal block 28 is attached to the ends of the terminal portions 26 and to the plates 48 in a manner to permit such relative movement of the plates 48 with respect to one another and corresponding movement of the ends of the terminal portions 26 which are attached to the plates.

Each plate 28 is correspondingly provided with top and

bottom flanges

49 and 50 respectively between which the inner end of the terminal block is interposed, as shown in FIGS. 1, 2 and 3 and each lower flange 50 is formed with a spring latch portion 50R which resiliently engages in a recess or notch 128 provided therefor in the underside of the terminal block 28 and each recess 128 is of substantially greater width than the width of the latch member 50R engaged therein, as indicated by the dotted lines at 128 and 50R in 'FIG. 1, to permit sidewise movement of the latches 50R in the recesses 128.

These spring latches cause the bottom wall 28B of the terminal block 28 to bear against the ends of the terminal portions 26 and against the protruding terminal wires 2ST, as shown in FIG. 3, so that the latches 50R are effective to hold the terminal block in position at the outer sides of the plates 48 and when the terminal 7 screws 428 are applied so that they project into the clearance pockets 44 they provide additional means for holding the terminal block 28 in assembled relation on the plates 48. The top flange 49 of one of the plates 48- is provided with a threaded opening therethrough for a screw 488 by which a ground wire is connected to the heating unit and the screw 488 is located at the pocket which contains the common terminal clip 43 but at a place where it makes no contact with'the exposed electrical conductors in the pocket.

' The plates 48 are permanently secured to the respective pairs of terminal portions 26 in a manner to provide a sealed eonnectionwlhich will preclude passage of grease or spillage there'through, and for this purpose the terminal portions 26 pass through plate openings which have annular flanges 48F projecting therefrom which are staked onto the sheaths of the terminal'portions 26 or welded thereto to fixedly secure the plates 48 to the terminal portions 26 and p'rovidea leak-proof connection.

s earer;

By reason of the upward and outward inclination of the terminal portions 25 from the bends 26A thereof grease and spillage from the cooking operations drains from the tubular sheathed elements at the hinged end thereof to the lower extremity of the bends 26A and does not flow outwardly along the inclined portions 26 to the outer ends thereof and moreover, any spillage that may reach the outer end of said portions 26, as for example, when the heating unit is tilted to the upraised position, is prevented by the plates 48 from reaching the end extremities of the portions 48 and the conductors within the terminal block, as such spillage drains downwardly on the plates 43 to the bottom flanges 50 and drips off therefrom.

The mounting of the pivot pin 34 in the flange 23V surrounding the opening in which the heating unit is located is advantageous as it not only provides a positive pivoting of the heating unit so that it swings readily to the upraised position without inconvenient manipulation which is oftentimes required when a loose composite sliding and pivoting is employed, but it also avoids the long offset arms which are required when the heating unit is pivoted underneath the range top at a distance from the range top opening in which the heating unit is located.

Thus short straight arms 24H may be employed for the hinging of the heating unit and the heating unit may be tilted to a highly upraised position affording ample access to the underside of the heating unit and to the interior of the mounting ring and to the pan therein.

In this upward tilting of the heating unit all of the terminal portions 26 that are at or beyond the bends 61 swing inwardly toward the center of-the opening in the mounting ring, and thepan is notched at 25C to provide clearance therefor in the upward tilted position of the heating unit.

In order that the pan 29 may have a receptacle portion to retain spillage therein, it is important that the pan 29 is of a substantial depth and with a conical surrounding wall with a substantial inward and downward slope at the hinged side thereof, so that the bottom of the notch 29C is considerably closer to the center of the pan than the open upper end of the notch so that the latterdoes not extend to or through the bottom of the pan but leaves a substantial receptacle portion therebelow to accommodate spillage therein.

While I have shown and described my invention in a preferred form, I am aware that various changes may be made therein without departing from the principle of the invention, the scope of which is to be determined by the appended claims.

What I claim is:

1. A surface heater of the class described comprising mounting means including an annular wall extending downwardly around and defining an upright opening, and an electrical heating unit of tubular sheathed embedded resistor type shaped in the form of a flat winding which is horizontally supported at the top of the opening and has a plurality of terminal stems extending downwardly therefrom in the opening and is swingable to an upraised position at one side of the opening, the heating unit being pivotally interconnected at said one side of the opening with the wall of the mounting by a hinge connection located adjacent to the periphery of the winding and pivotally operable about a pivotal axis line transecting the opening at an elevation therein at said one side thereof for swingability of the winding about said pivotal axis line to said upraised position, the said terminal stems having end portions thereof disposed in generally parallel relation and extending collectively outward from the opening at a level below and in a direction transverse to the said pivotal axis line and pivotally operable about said pivotal axis line to swing downwardly as the winding swings to the upraised position thereof.

2. A surface heater of the class described comprising mounting means including an annular wall extending downwardly around and defining an upright opening, an electrical heating unit of tubular sheathed embedded resistor type shaped in the form of a flat winding with a plurality of terminal stems projecting therefrom, the winding being horizontally supported at the top of the opening and having the terminal stems thereof projecting downwardly therefrom in the opening, and hinging means by which the heating unit is pivotally connected adjacent to the periphery of the winding at one side of the opening to thedownwardly extending annular wall on a pivotal axis about which the winding is swingable to an upraised position at said one side of the opening, the hinging means being disposed in a position in which said pivotal axis extends across the opening at said one side thereof at an elevation therein with the annular wall at said one side of the opening bulging outwardly from and extending downwardly below the pivotal axis at one side of the pivotal axis and the stems extending downwardly below the pivotal axis at the opposite side of the pivotal axis and continued collectively outward below the pivotal axis and underneath and beyond the annular wall at said one side of the opening in a direction transverse to the pivotal axis.

3. A' surface heater as defined in claim2 wherein the hinging means thereof comprises laterally spaced arms which are located below and attached to the winding and extend outwardly therefrom and the downwardly extending annular wall has a pair of laterally spaced substantially vertical slots into which the outer ends of said arms project at the place where the heating unit is pivotally connected to the annular wall.

4. A surface heater as defined in claim 2 wherein the hinging means thereof comprises laterally spaced arms which are located below and attached to the winding and extend outwardly therefrom and the downwardly extending annular wall has a pair of laterally spaced substantially vertical slots into which the outer ends of said arms project at the place where the heating unit is pivotally connected to the annular wall, and between said slots the said wall has secured thereto at the outer side a spring engaging the outer ends of said arms to hold the heating unit at the extremes of its pivotal movement.

5. A surface heater as defined in claim 2 wherein the hinging means thereof comprises laterally spaced arms which are located below and attached to the winding and extend outwardly therefrom and the downwardly extending annular wall has a pair of laterally spaced substantially vertical slots into which the outer ends of said arms project at the place where the heating unit is pivotal- 1y connected to the annular wall, and the laterally spaced arms are end portions of two straps shaped to form a spider by which the flat winding is supported and to which it is secured.

6. A surface heating unit and mounting comprising a heating unit of tubular sheathed embedded resistor type shaped in the form of a flat winding, and mounting means therefor wherein a top wall extends around and has 9. depending annular flange supported thereon and defining an opening in the top of which the flat winding is normally supported, the heating unit being provided with hinging means by which it is pivotally connected adjacent to the periphery of the winding to the depending annular flange on a pivotal axis extending across the said opening at one side thereof and the flat winding being swingable on that pivotal axis from its normally supported position in the upper end of the opening to an upraised position at one side of the opening, and the heating unit having opposite end portions of the tubular sheath thereof which in the aforesaid normally supported position of the heating unit extend downwardly from the flat winding to continuations thereof which project outwardly below the said pivotal axis in a direction crosswise thereof to a place underneath said top wall.

7. A surface heating unit and mounting as defined in claim 6 wherein the said continuations have electrical conductors projecting from their outer ends and a terminal block of electrical insulating material is attached to the outer ends of said continuations and contains said projecting electrical conductors and facilities for connection of current supply conductors thereto.

8. A surfaceheating unit and mounting as defined in claim 6 wherein the continuations in said normally supported position of the heating unit are upturned.

9. A surface heating unit and mounting as defined in claim 6 wherein a pan is supported by said annular flange and is located underneath the Winding and has a downwardly and inwardly sloping side wall at the side of the opening where the heating unit is hinged to the flange, and said side wall has "a notch at a substantial elevation above the bottom of the pan through which the said continuations project and in which said continuations are swingaJble by tilting the heating unit to the upraised position thereof.

7 10. In a stove-top heater unit for electric stoves, a mounting ring having a rim and a depending flange at its inner edge and an inward support flange about the lower edge of said depending flange, a support spider disposed within said depending flange and having hinge arms thereon having ends thereof extended outwardly through said depending flange, a heating element carried by said spider, a pivot pin extended through said hinge arms and said depending flange to pivot said spider for movement be- Y a 10 tween an upright open position and a horizontal position of use, said pivot pin being disposed on an axis extending as a chord with respect to said depending flange, spring means mounted on the outer side of said depending flange intermediate said ends of said hinge arms, and bearing against the outer ends of said hinge arms for yieldingly retaining said spider in either of said positions. 11. In a stove-top heater unit for electric stoves, a mounting ring having a rim and a depending flange at its inner edge, said depending flange having a pair of laterally spaced vertically extended slots therein with opposite edge portions of said slots formed to provide opposed arcuate bearing elements, a support spider disposed within said depending flange and having hinge arms thereon having ends thereof extended through said slots in said depending flange, a heating element carried by said spider, and a pivot pin extended through said hinge arms and supported in said bearing elements at opposite sides of said slots to pivot said spider for movement between an upright open position and a horizontal position of use.

References Cited in the file of this patent UNITED STATES PATENTS 2,271,977 Hjelmgren Feb. 3, 1942 2,368,051 Tuttle Jan. 23, 1945 2,624,827 Young Jan. 6, 1953