US2289891A - Appliance - Google Patents

Description

July 14, 1942.

R. WEEKS APPL-IANGE Filed Dec. 22, "1958 Inventor: Walter R. Weeks,

His Attorney- Patented July 14, 1942 APPLIANCE Walter It. Weeks, Hamden, Gonm, assignor to General Electric Company, a corporationof New York Application December 22, 1938, Serial No. 247,246

4 Claims.

My invention relates to domestic appliances and more "particularly to electric heating appliances and has for its object the provision of an improved construction and arrangement for supporting such appliances. While not limited thereto, this invention is particularly applicable to the flat plate type of electric heater commonly called a hot plate.

My invention has for its specific objects the provision in a hot plate heater of a supporting construction and arrangement which can be manufactured at low cost; which can bequickly and economically assembled; which presents a pleasingfinished appearance; which prevents the accumulation of food and other substances around the supporting structure; and which can be readily cleaned.

Furthermore, the frames of many of'the appliances of this type are finished with-a coating of vitreous enamel which may be readily cracked or chipped if subjected to strains. It is therefore an additional important object of my invention to so construct and arrange the means for supporting the frame that no forces are transmitted therefrom to the-vitreous enamel surface of the frame.

In accordance with my invention in one form thereof, these and other desirable objects are obtained in a hot plate type of heater by providing a supporting frame of box-like construction which is provided with integral corner sections arranged to subtend the angle between adjacent side walls. The frame may be either drawn from a single sheet of metal in which case the corner section constitutes a single piece of metal integral with the frame or it may be fabricated by suitably bending a sheet of metal in which case the corner section comprises integral portions of adjacent side walls bent in overlapping relation and suitably held together, Detachably mounted on each of these corner sections, by means concealed from view, are curved legs adapted to overlap adjacent side walls and the top wall. In those cases where the frame is coated with a vitreous enamel, strain relief portions are provided in the overlapping sections of each of the less.

For a more complete understanding of this invention, reference should be made to the accom panying drawing in which Fig. 1 is a front elevation, partly in section, of a two-element hot plate type of electric heater embodying one form of my invention; Fig. 2 is a plan view, partly in section, of the left-hand portion of the heater shown in Fig. 1; Fig. 3 is a detail sectional view 7 Figs. 1,2 and 3, I have shown my invention in one form as applied to a two-element flat plate electric heater. It is to beunders'tood, however, that this particular heater is used merely for the purposes of illustration and my invention may be used with a heater having one or more elements. The heater illustrated comprises a box-like casing or frame I0 having four side walls and a top walll l which is provided with suitable openings i2 in which are mounted two heating units l3 and Hi.

The heating units 13 and I 4 may be of any suitable type but are preferably of the type describedand claimed in the United States patent granted to W. A. Rankin No. 1,522,206 dated J anuaryfi, .1925. lBriefiy, these heating units comprise a disk' I5 made of any suitable heat refractory insulating material, suchas high temperature porcelain. This disk I5 is provided with a groove. I6 'in which the helical resistance element H is supported. The groove I6 is polygonal in form being shown as six-sided or hexagonal. At the angles or corners of the hexagon the inner walls of the groove :are provided respectively with overhanging projections or recesses (not shown) by means of which the heating element may be slipped easily in place and held under the projections. The disk I5 is set into the openings I2 provided in thetop wall H and is supportedin each opening by means of pairs of diametrically opposed flanges 18 and I9. Suitable screws 2i! are used to fasten the refractory plates Hi to the flanges 19.

Apertures 2| are provided in the disk at each end 22 and at the center 23 of the groove, the heating element being secured to suitable terminal. studs 24 provided in these apertures. It will be understood that these terminal studs 24 are electrically connected by means of suitable leads (not shown) with three terminals respectively and that these terminals in turn are electrically connected by suitable leads (not shown) with a suitable controlling switch 25 having a control knob 26 extending through the front wall of the frame l0. --As illustrated, a separate controlswi'tch is provided for each heating unit and each switch 25 is of the three way type having low, medium and high heat positions so that the two portions of the resistance element may be energized in series relation or one element alone may be energized or both elements may be energized in parallel relation. In addition, each switch is provided with an off position so that the associated heating unit may be completely disconnected from its supply source.

The frame may be of any convenient shape and is shown substantially rectangular. It may be fabricated in any suitable manner but it is preferred to form it by bending a single piece of metal to the desired box-like shape. It will be observed that integral corner sections subtending the angle between adjacent side walls are provided at each corner of the box-like frame. In the preferred embodiment these corner sections form substantially equal angles with the adjacent side walls, are substantially flat, and are of substantial width. The corner sections are formed by bending the ends 2'! and 28 of the adjacent side walls so as to form an overlapping joint. In the preferred embodiment of this invention the overlapped ends of the side wall are spot welded together in order to maintain them in fixed relation during the remainder of the manufacturing operations. Holes 29 and 3B are provided in each corner section through which are adapted to extend fastening means for supporting legs as will more fully appear hereafter.

As shown in Figs. 1 and 2 a flange 3] is provided on the four side walls of the frame In along the bottom edge thereof. This flange is formed by bending inwardly the bottom edgeof each side wall and it is adapted to support a bottom plate 32 which is so positioned that it rests on top of the flanges provided on the end walls of frame In and underneath the flange provided on the front and rear walls. With such an arrangement, the bottom plate I3 is firmly held inplace and encloses the space below the heater elements to prevent accidental contact with the electrical connections therein. In addition, the bottom plate 32 is provided with a polished surface which serves as a reflector of heat therebyimproving the operating characteristics of the heater.

Detachably mounted on each of the four corner sections of the frame II), in a manner more fully described below, is a, leg 33. Each leg 33 has a curvature corresponding to an arc of 120 which is sufficient to substantially overlap the adjacent side walls forming the corner section to which the leg is applied, as shown in Figs. 3, 4, and 6. Referring particularly to Fig. 6, it will be observed that an inwardly extending fiattened surface or flange 34 is integrally formed on the upper end of each leg. This flange is adapted to cover and conceal from view the lapped joint of the corner section and to substantially overlap the adjacent corner portions of the top plate I Provided at the lower end of the leg 33 is a second integrally formed flange 35 having a hole arranged centrally thereof into which is inserted a rivet 35 for suitably fastening a foot 36 made of a suitable non-metallic material. The legs 33 are die cast from any suitable metal and the exterior surface may be chromium plated so as to present a smooth polished surface. A pair of vertically spaced bosses 31 are cast integrally on the inside surface of each leg portion. In addition, a recess 38, the purpose of which W ll be more fully described hereinafter, ,is provided along the portions of each leg which overlap the walls of frame In.

As previously stated, the legs '33 are detachably mounted on the frame Ill. The legs are placed in position over the corner sections so that the bosses 31 are in line with holes 29 and 30 provided in the corner section. The legs 33 are then firmly but detachably secured to the frame by means of screws 39 which pass through the holes 29 and 3D and into the bosses 31. The screws 39 are of the self-tappin type.

In some cases, it is desirable to finish the frame In with a suitable enamel coating. In these instances, the casing is enameled after the corner sections are secured together and before the corner supports are placed in position. In Fig. 3, the cross-section illustrated shows a corner post attached to such an enameled frame. The finish coat of enamel is represented by the wide dark line 40 and the ground coat of enamel by the narrow dark line 4|. With such an enamel coating, it is important that the corner post be provided with some means for preventing any strains being transmitted from the corner supports to the enamel finish 4!] coat in order to prevent chipping and otherwise straining this finish. In accordance with this invention, a strain relief recess 38 is provided in the overlapping portions of the edges of the legs 33. Sufficient metal is cut away along each edge so that when the corner post is assembled, the edges will be adjacent to but out of contact with the finish coat of enamel so as to transmit no force thereto.

In Fig. 4 is illustrated a modified form of this invention. In this form, the frame 10 is drawn from a single piece of metal and the corner sections 42 are made of one piece eliminating the lap joint corner section illustrated in Fig. 3. In addition, an alternative means for attaching the corner post to the frame is illustrated. In this instance, an additional boss 43 is die cast on the boss 31. This boss 43 is of such diameter that it readily passes through holes, similarly spaced as holes 29 and 33 shown in Fig. 1, provided in the corner section 42. The legs are firmly mounted on the frame by placing them so that the bosses 43 pass through the holes provided in the corner sections. The bosses 43 are then hammered or peened over so as to firmly wedge the corner section 42 between the peened head of boss 43 and the shoulder formed by boss 31. In the arrangement shown, no strain relief recesses are provided in the edges of the legs 33. However, if an enamel finish is placed on the drawn casing, it will be understood that strain relief portions similar to those illustrated in Fig. 3 would be employed.

In Fig. 5 is illustrated a further modification of my invention. In this alternative arrangement, a corner section formed by overlapping a portion of the adjacent side walls is provided with mechanical means for holding the walls in overlapped position during finishing and assembling operations. In this modification, integral portions 2'! and 28 of adjacent side walls of the frame ID are bent inwardly in overlapped relation forming a corner portion which subtends the angle between the adjacent side walls. Vertically extending ribs 45 and 46 are then pressed into the portions of the adjacent side walls which overlap so that engaging surfaces have a complementary configuration. These ribs 45 and 46 are sufficiently deep to hold the side walls firmly in position without employing any other means such as spot welding as used in the arrangement shown in Fig. 3. A leg 33 is detachably mounted on the corner section by means of self-tapping screws 39 in a manner similar to that described in connection with Fig. 3. In the arrangement illustrated, the frame It) is coated with vitreous enamel and the strain relief arrangement of this invention is used.

While I have described my invention with reference to a two-element hot plate type of heater, it is apparent that it is applicable to domestic appliances in general. I therefore do not desire my invention to be limited to the particular construction shown and described, and I intend in the appended claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an appliance, a substantially rectangular shaped frame having a top wall and side walls, corner sections comprising integral portions of adjacent side walls bent in overlapping relation so as to subtend the angle between said adjacent side walls, substantially curved legs adapted to cover said corner sections and overlap adjacent wall portions of said frame including said top wall, bosses on said legs, and means extending through said corner sections and into said bosses firmly attaching said legs to said corner sections, said means being concealed from view.

2. In an electrical heating appliance, a frame having a top wall and a plurality of side walls, integral corner sections subtending the angle between adjacent side walls, said corner sections being provided with a plurality of holes, legs adapted to cover said corner sections and overlap adjacent walls of said frame, a plurality of bosses integral with said legs, and a second boss integrally formed on each of said first mentioned bosses and extending through said holes, said second boss being headed so as to firmly attach said legs to said corner sections.

3. In an appliance, a supporting frame having a top wall and a plurality of side walls, substantially flat corner sections subtending the angle between adjacent side walls and having therein pairs of vertically spaced openings, substantially curved leg members adapted to cover said corner sections and overlap adjacent wall portions of said frame including said top wall, a pair of vertically spaced bosses on each of said leg members adapted to be aligned with said pair of openings in each of said corner sections, and means associated with said bosses and extending through said openings for securing said leg members to said flattened corner sections.

4. A supporting leg for a heating appliance comprising a substantially curved member having an upper and a lower end, a flange on said upper end, a flange on said lower end having an opening therein, a plurality of bosses vertically spaced between said flanges, and a nonmetallic supporting member mounted in said opening in said lower flange.

WALTER R. WEEKS.

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