US 2260165 A
Description (OCR text may contain errors)
Oct. 21, 1941. E. N. CALHOUN HEATING MEANS Filed June 6, 1940 lNvzNToR .ERN E51 N CALHOSLN ATTOQN Ers Patented Oct. 21, 1941 UNITED STATES PATENT OFFICE HEATING MEANS Ernest N. Calhoun, Pittsburgh, Pa., assignor to Edwin L. Wiegand, Pittsburgh, Pa.
Application June 6, 1940, Serial No. 339,119
This invention relates to heatingmeans, more particularly to electrical heating means adapted generally for use with appliances which are to be electrically heated, illustrative examples of which are ranges or stoves, hot plates, and the like, The principal object of this invention is to provide new and improved heating means of the character described.
In the drawing accompanying this specification, and forming a part of this application, I have shown an embodiment which my invention may assume, and in this drawing:
Figure 1 is a vertical sectional view of the embodiment of the invention herein illustrated, the line'of section being generally shown by the section line l-I in Figure 2, a
Figure 2 is a bottom plan view of the embodiment, parts being broken away to more clearly show the construction,
Figure 3 is a fragmentary separated perspective view of certain parts of the embodiment, and Figure 4 is a bottom plan view ofthe heating unit.
The embodiment of the invention herein shown is particularly adapted for use as a range unit, and as shown in Figure 1, comprises a support, which inthe particular embodiment is in the form of a disk-like metallic plate i0, preferably formed by a casting operation, and constituting part of the heating unit. The top side, referring to the position of parts in Figure 1, is preferably Electrical resistor means, and heat-conducting electric-insulating means are disposed in the grooves formed in the lower side surface of the plate l0. As herein illustrated, a single length of electrical resistance wire of the helically wound type, either round in transverse section, as shown,
case, the refractory material is compacted in the grooves H and i2 in such manner that the resistors and 2| are embedded therein, and are thus held spaced from those surfaces defining flat and provides a heating surface on which arti-.
cles, such as pots, pans, kettles, or the like, are supported. The lower side of the plate In is formed with channel means, as by grooves II and I2, which are here formed as spirals and are intercalated with respect to each other, as best seen in Figure 4.
The marginal edge of the plate I0 is formed with annular downwardly extending peripheral flange means 13, and extending radially from the flange means l3 are a plurality of projectionsl4, here shown to be three in number, these projections being engageable within corresponding apertures l5 formed in a rim 16 of an adapter adjacent surfaces of the adapter ring I! and the' stove portion I 9., so that direct contact between the heating surface and the article to be heated is provided for.
therespective groove, as best seen in Figure 1. Each of the resistors 20 and 2| has a pair of connection leads 22 and 23 respectively, extending outwardly from the insulating material, as best seen in Figures 2 and 4.
A preferred method of properly positioning the resistors and the refractory material in the grooves of the plate comprises disposing the plate l0 groove side up on a suitable support, and loosely filling the grooves H and I2 with'the refractory material, such material preferably being mixed with a certain amount of bonding clay, and moistened so that it maybe worked somewhat like founders clay. The excess material from the upper side of the plate l0 (remembering providing a suitable die having projections shaped to closely flt the grooves H and I2, such projections carrying the resistors 20 and 2|, the latter and plate are separated, the resistors are properly held positioned in the refractory material in respective grooves. The grooves may then again be filled with loose refractory material, and the excess material wiped from the plate, as before, and a die, somewhat like the die before described, but without resistors, is brought together with the plate It, to compact the refractory material. The heating unit may then be dried or baked, if desired.
' The lower side surface of the plate Iii is formed with laterally extending centrally disposed circular flange means 25, circumscribing an opening 25 extending through the upper side of the plate I0, and at such upper side the opening is formed with an enlargement 26, forming a shoulder El. The marginal surface defining the opening 25 has such contour as to provide an annular lip 28 so constructed that the shoulder 2? forms the bottom of an annular recess, as best seen in Figure l. The terminating margin 29 of the flange means 2 3 is formed with spaced-apart recesses or notches .30, here shown to be two in number and diametrically opposed.
Reflector means 3| is provided for assembly with the heating unit, and in this embodiment comprises a metallic shallow cone-shaped wall 82 having a central, generally flat portion 33 which is formed with a central aperture defined by an upstanding annular lip 36. Projections 85, corresponding in position and number to the recesses or notches 39, are struck-out from the flat portion 83, and are constructed to engage within respective recesses 3s. The edge margins of the wall 32 are curved upwardly, as shown at at, and adjacent this edge margin. the reflector may be .formed with a pair of diametriof the resistors 2t and 2!, and these r heans may take the form of the binding posts iii and 38, as herein shown, which are respectively connected to the leads 22 and 23. The binding posts, it will be appreciated, are electrically insulated-from the reflector means 530, as for instance in the manner shown in the drawing.
.Means as is provided for holding the reflector means 3i asembled with the heating unit. The holding means 89 extends from the heating unit, through the opening 25 and isv constructed and arranged to press the reflector against the heating unit. the particular embodiment of the invention, the holding means- 89 comprises an upper headed portion formed by a generally inverted cup-shaped member till, the end wall of which is curved to facilitate connection thereto of a screw-threaded stud 6i, and comprises also an outer inverted cup-shaped member 6?, arranged to receive the member 6E3 substantially in nesting relation. The members it and 62 are held together in any suitable manner, preferably by a force fit. The outer member d2 may be of anfornamental nature, and may carry indicia, such as that suggested at 63, on its end wall. The flange wall of the outer member 62 is of a greater extent than the flange wall of the member 40, so that the terminating margin of the flange wall of the member d2 bears against the shoulder 2?. length that it passes through the opening 25, gird through the aperture in the reflector means A lower headed portion, for pressing the refiector means against the heating unit, comprises a cup-shaped? member 84, having its closure wall dished inwardly, as shown at 25, to form a recess for receiving a washer 46 and nut 41. The end wall or the member, is apertured The screw stud M is of such bit to pass the stud thand the flange wall of the member dd is of such diameter that its terminating margin bears against the adjacent surface of flat portion 32-3 of the reflector means 3i. When the nut i? is drawn up, the member 44 causes the reflector means to bear against the terminating margin ofthe flange means 24. Thus, the projections 35 are held in the recesses or notches 30 and prevent relative rotation of the reflector means with respect to the heating unit about the holding means.
The parts of the heating means hereinbefore described may be assembled in any desirable manner. By way of example, the binding posts 3'! and 38 may first be properly assembled on the reflector means ti, and then the conductor leads 22 and 23 may be secured to respective binding posts. As best seen in Figure 1, the up! per end of each binding post is bifurcated, as
shown at 13, and the respective conductor lead is placed between the furcations, and the tunations are then squeezed tightly about the conductor lead. If desired, the conductor leads additionally may be soldered to their respective binding posts.
The reflector means 39 may then be positioned with respect to the heating unit, in such manner that the flat central portion 33 bears against the terminating margin of the flange means 26, and the projections 35 are positioned within respective recesses or notches 3d. The assembled cup-shaped members 438 and d2, carrying the screw stud 65 may then be disposed so that the terminal margin of the flange of the member 12 bears against the ,shoulder 2i and the stud M extends through the opening 25 and the aperture in the reflector means 3i. As clearly seen in Figure l, the outer member G2 is so constructed that its flange fits within the enlargement 25 of the opening 25, and its top wall does not extend beyond the plane of the upper flat surface of the heating unit iii.
The cup-shaped member 54% may then be placed in position on the stud iii, and the washer tit and nut d? assembled with the stud hi, the nut being drawn up sufic'iently so that the member 36 presses the flat central portion 33 of the reflector means 3i against the terminating margin of the flange means 25. It will be clear that the interfitting recesses 3d and projections 35 prevent relative shifting of the reflector means and the heating unit during and after assembly thereof, and therefore certain parts, like the conductor leads, binding posts, and insulating material, are not subjected to strains which might be set up if relative shifting were not prevented; Also, the recesses 30 and projections 35 provide for a predetermined assembly of the heating unit and reflector means.
As shown in this embodiment, referring particularly to Figure 2, two of the binding posts 8? and 38 are connected together by a jumper strap 39, the binding post 38 of this connection also having attached thereto a conductor strap ductor straps 53 and 54 respectively connected thereto, these straps also leading to the termi- I nal block 5!. and having screw-connections 55 and 56 respectively, for receiving and holding conductors leading from a source of energy- A ground conductor, such as the conductor strap 51, may be connected to the reflector means, this strap having a connection screw for receiving and holding a conductor leading to a suitable ground.
It will be appreciated that the terminals 52, 55, and 56 may be connected in electrical circuit in such manner that one, or the other, or both, of the resistors and 2| may be selectively energized. The particular construction of the heating unit makes it non-susceptible to warping, apparently because of the provision of the centrally disposed flange means 24, or the peripheral flange means l3, or the-combination of the two. i
From the foregoing it will be apparent to'those skilled in the art that I have accomplished at least the principal object of my invention, and it also will be apparent to those skilled in the art that the embodiment herein described may be spaced from said opposite side, and having a portion bearing against said plate means; a plurality of connection posts-carried by but insulated from said reflector means, said posts being electrically connected to respective connection leads;
plurality of connection leads; reflector meansv holding means, constructed and arranged to press said reflector means portion, against said plate means; and means, in part carried by said plate means and in part carried by said reflector means, constructed and arranged to prevent relative shifting of said reflector means and said plate means about said holding means.
2. Heating means, comprising: a cast-metal plate, having opposite sides, one side providing a heating surface, and the opposite side being provided with channel means, and'having central laterally extending flange means; granular refractory insulating material retained within said channel means; electric resistor means, em-
bedded in said insulating material, in such manner that said resistor is held spaced from those surfaces defining saidchannel means, said resistor means having a plurality of connection leads extending outwardly from said material; reflector means, positioned adjacent to said opposite side, and having a central apertured portion bearing against the terminating surface of said flange means, said-reflector means having also a plurality of binding posts to which said connection leads are respectively electrically connected; holding means, comprising a screw stud extending from said plate and through said reflector means aperture, and nut means threaded on said stud and pressing said reflector means portion against the terminating surface of said flange means; said flange means being formed with a plurality of recesses and said reflector being formed with corresponding projections and arranged as to prevent relative rotation of said reflector means and said plate about-said stud.
3. Heating means, comprising: a support, having opposite sides, and having a tubular flange extending laterally from one of said sides; reflector means, spaced from said one side,
and having a portion bearing against the terminating margin of said tubular flange; holding means extending from said support through said tubular flange and to said reflector means, con-- structed and, arranged to press said reflector means portion against said terminating-margin; and means, in part carried by said reflector means and in part carried by said tubular flange,
constructed and arranged to prevent relative shifting of said reflector means and said support about said holding means.
4. Heating means, comprising: a heating unit, having opposite sides, and having also an aperture extending therethrough, said aperture having an enlarged portion entering from one side and forming a shoulder with the remaining portion of said aperture; reflector means, positioned adjacent the opposite side of said heating unit, and having a portion bearing against said heating unit, said portion being apertured; and holding means, comprising inverted cup-shaped means disposed within the enlarged portion of said heats ing unit aperture and having its terminating margin bearing against said shoulder, saidinverted cup-shaped means having a screw-threaded stud extending through the apertures in said heating unit and in said reflector means, and said holding means comprising also cup-shaped means having an aperture passing said stud, and nut means threaded on said stud and pressing the terminating margin of said cup-shaped means against said reflector means portion.
5. Heating means, comprising: a support, carrying heat producing means; reflector means, positioned adjacent to said support, and having a portion bearing against said support; holding means, holding said reflector means in assembled relation with said support; and means, comprising interfltting projection means and recess means, in part carried by said support and in part carried by said reflector means, constructed and arranged to prevent relative shifting of said reflector means and said support about said holding means.
6. Heating'means, comprising: a support, having flange means extending from a surface thereof, said flange means having recess means in its means portion.
7. Heating means, comprising: a heating unit, having opposite sides, and having also an aperture extending therethrough, said aperture havingan enlarged portion entering from one side and forming a shoulder with the remaining portion of said aperture, and said heating unit having a tubular flange adjacent said aperture and extending from the opposite side, said flange having recess means in its terminating margin; re-
1 flector means, positioned adjacent said opposite side of said heating unit, and having a portion bearing against the terminating margin'of said fitting in respective recesses and so constructed 7! tubular flange, said portion being apertured, and
having projection means fitting into said recess means; and holding means, comprising inverted cup-shaped means disposed within the enlarged portion ofsaid heating, unit aperture and having its terminating margin bearing against said shoulder, said inverted cup-shaped, means having a screw-threaded stud extending through the apertures in said heating unit and in said refiector, and said holding means comprising also cup-shaped means having an aperture passing said stud, and nut means threaded on said stud and pressing the terminating margin of-said cupshaped means against said'refiector means portion.
8. Heating means, comprising: a support; electrical insulating material carried by said support; electrical resistance means, carried by said insulating material, and having extending terminal means; reflector means, having connection means to which said terminal means are connected; holding means, constructed and arranged to hold said reflector means assembled with said support; and means, separate from said terminal means,
constructed and arranged to prevent relative shifting of said reflector means and said support about said holding means; so that said terminal means are relieved of the strain of opposing such relative shifting.
9. Heating means, comprising: a support, having recess means in a surface thereof; granular refractory insulating material disposed within said recess means; electrical resistance means embedded within said insulating material, and having terminal means extending from said insulating material; reflector means, having 'connection means to which said terminal means are connected; holding means, constructed and arranged to hold said reflector means assembled with said support; and means, separate from said terminal means constructed and arranged to prevent relative shifting of said reflector means and said support about said holding means, so that said terminal means are relieved of the strain of opposing such relative shifting.
ERNEST N. CALHOUNL