US2555841A - Heating apparatus - Google Patents

Description

June 5, 1951 E, cLARK 2,555,841

HEATING APPARATUS Filed Aug. 28, 1948 2 Sheets-Sheet 1 FIG.

v INVENTOR WITNESSES EARL K. CLARK June 5, 1951 Filed Aug. 28, 1948 E. K. CLARK HEATING APPARATUS 2 Sheets-Sheet 2 42 I 8 INVENTOR EARL K. CLARK 4 ATTORNEY Patented June 5, 1951 HEATING APPARATUS Earl K. Clark, Mansfield, Ohio, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa, a corporation of Pennsylvania Application August 28, 1948, Serial No. 46,599

3 Claims.

This invention relates to a range construction and, more particularly, to a range oven assembly in which uneven expansion of the oven liner due to baking heat is controlled to prevent variable baking conditions which would otherwise be normally incurred.

In a present construction, although the oven liner is drawn toward the rear of the range body, nevertheless, when heated, it expands unevenly and has a tendency to move forward in its lower portion, causing the normal air gap between the lower portions of the oven door and the liner flange to decrease. In some cases, this air gap is completely taken up cutting on" the desired air intake to the oven. In extreme cases, the forward movement of the liner may exceed the gap width with the result that the oven door is moved outwardly, causing a variable gap to appear at the top of the door. To overcome this effect, the gap provided is considerably wider than necessary to provide good baking results, the additional width serving to allow for forward expansion of the oven liner when heated. A small controlled gap between the door and the liner flange is desirable and acts as an air intake for the oven venting system. A controlled air intake is necessary for distribution of heat for critical baking operations. When the normal air gap is taken up or shifted due to expansion of the oven liner, the heat distribution is upset and the thermal efficiency of the oven is impaired.

It is an object of this invention to provide a range oven construction having an air intake gap which is substantially uniform at all oven operating temperatures.

Another object of this invention is to provide a range oven construction having a narrow air intake gap which may be attained consistently from oven to oven for all oven operating temperatures.

It is a further object of this invention to provide a range oven construction having an air intake gap which may be adjusted when the oven is cold, Without the necessity of allowing for restriction due to expansion of the oven.

It is a still further object of this invention. to provide a range oven construction in which chipping or cracking of the porcelain surfaces due to thermal metal expansion is. reduced.

These and other objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a perspective view of a range with some parts omitted or in section for clarity;

Fig. 2 is a perspective view of the oven liner assembly;

Fig. 3 is a vertical cross section of the range shown in Fig. 1, but greatly enlarged;

Fig. 4: is a cross section taken on line IV-IV of Fig. l, greatly enlarged;

Fig. 5 is a View similar to Fig. 4 but showing the location of the door pivot;

Fig. 6 is a view similar to Fig. 3 ShOWiIlg another embodiment of the invention; and

Fig. '7 is a front perspective view of the oven liner shown in Fig. 6.

Referring to the accompanying drawings in detail, as best illustrated in Fig. l, a range structure is shown including a porcelain coated 'plat form Ill supported by and fastened to a porcelain coated wall structure i2. A porcelain coated inner oven wall structure or oven liner I6 is disposed within the enclosure formed by the wall structure and platform.

The enclosing Wall structure 12 comprises a plurality of angularly related walls which include side walls l8, a front Wall 20 and a rear wall 22.

The oven liner l6 comprises a plurality of walls which include a rear wall 24, side walls 25, a top Wall 28 and a bottom wall till formin a baking compartment closed on all sides except the front. The front marginal portion of the oven liner is bent outwardly to provide a peripheral flange comprising a top flange 32, a bottom flange 34, and side flanges 36. An air vent 3i is provided in the rear portion of the oven liner top wall 28 to permit the exit of food vapors. Although I have shown the vent in the top wall, it will be understood that the vent may be disposed in the rear or side walls as desired. Attached to the rear face of the bottom flange 34 as by spot-welding (denoted by X5) is a flat strip member 38.

The front range wall 20 has an opening formed therein defined by a plurality of inwardly displaced lateral flanges including a top flange 40, a bottom flange 42 and side flanges 44. The bottom flange 42 has the greatest inward displacement while the top flange 49 has the least displacement, the side flanges being slightly oblique to provide a flush contour. The oven liner iii is inserted through the flanged opening and is positioned therein by abutment of its top flange 32 with the top wall flange 4i] and abut?- ment of its lower flange strip member 38. with the bottom wall flange 42.

A horizontal internal wall 46 is disposed within the wall structure If and is attached thereto in any desirable manner. A plurality of Z-shaped brackets 48 are positioned upon and fastened to the horizontal wall 46 at the rear end thereof to support the rear end of the oven liner it. These brackets allow the oven liner to move rearwardly, since they are not fastened to the liner, but merely support it.

The oven liner may be removably attached to the rear wall 22 by a plurality of J-bolts 553 inserted through openings therein. The oven liner side walls 26 are provided with openings 52 adapted to be engaged by the hook portions of the J-bolts and the oven liner is then urged rearwardly by tightening the J-bolts.

As best shown in Figs. 2, 3, and 4, the oven liner strip member 38 is rigidly fastened to the wall flange 42 by a plurality of screws 54. These screws are inserted through openings 56, disposed in the strip member 38 and in registry with mating openings in the wall flange 42. An angular gap A is formed between the oven liner side flanges 36 and the front wall side flanges 44, which gap at the bottom is the width of the strip member 38 and tapers off to zero at the oven liner top flange 40. A bakin element covered by a battle E (shown in dot-dash lines) is disposed in the lower portion of the liner in close proximity to the bottom wall 30 and extending substantially from front to rear, hence the greatest expansion will occur in the lower portions of the liner. the bottom in the high expansion area and diminishes proportionately upwardly in the low expansion area. Because of the uneven liner expansion some distortion of the liner side flanges is unavoidable. The gap A is sufflcient to permit any such distortion to occur without abutment of the wall side flanges and the oven liner side wall flanges. Thus, the stresses on the porcelain coated flanges are minimized, reducing the possibility of chipping and. cracking the finish.

A loosely fitting door 58 disposed within the front wall opening provides a closure for the oven liner. As shown in Fig. 5, the door is pivotally supported in its lower portion by a bracket 60 of any conventional type desired. The door may be of sheet metal structure and so formed as to provide an internal hollow space which is filled with a heat-insulating material 62 such as, for example, spun glass. The door has a peripheral lateral flange 64 which overlies the oven liner flanges 40-, 42 and 44 when it is in closed position. The upper portion of the door flange abuts the top oven liner flange 32, but since the door is disposed in vertical position, the side and bottom portions of the door flange are in spaced relation to the side and bottom flanges 36 and 34, respectively, of the oven liner, providing an angular gap B which is widest at the bottom of the door and diminishes to zero at the top.

The gap B serves as the air intake for the oven liner l6, allowing cool air to enter at its lower portion, and hot gases to rise to its upper portion and escape through the bent 31. This air circulation provides more uniform heating within the oven liner. This gap is unaffected by heat expansion of the oven liner since the liner is fastened to the front wall flange 42 and any movement is directed rearwardly, thus predetermined venting is provided for all baking temperatures. Since the front wall flanges are The gap A is widest at inclined to the vertical, a flush relationship between the exterior of the doo 58 and the front wall 20 is attainable, providing a neat and pleasing appearance to the front of the range.

Since a constant gap is assured by this invention,the air gap B can be made smaller than has heretofore been the practice, with no danger of harmful restriction upon heating.

Also, since the oven liner is free to expand and contract unevenly without binding, no

stresses will be imposed on the front wall of the range by liner warpage to chip and crack the brittle vitreous enamel or porcelain surfaces.

A modification of this invention is shown in Figs. 6 and 7 of'the drawings in which the strip member 33 is replaced. These figures are fragmentary views, since most of the structure is the same. In this embodiment, the oven liner It has a lower flange 34a which is ofiset rearwardly by a bent back portion 70. The side flanges 36 are disposed flush with the bent portion 70 and are inclined to the vertical. The lower flange 34a is rigidly fastened to the flange 42 in any manner desired, as for example by screws 12.

The tapered gap A between the oven liner side flanges 36 and the wall opening side flanges 44 will be attained as in the first embodiment, thus allowing uneven expansion to occur in the oven liner without interference from the wall openings flanges. Any expansion will also be directed rearwardly, since the oven liner is firmly anchored to the front wall by the screws '12.

The oven door 58 is disposed flush with the front wall 20 of the range, providing a tapered air intake gap B which is unaffected by oven cooking temperatures.

The controlled air gap B between the oven liner and the door lends itself to rapid and accurate adjustment, and may therefore be advantageously set on a moving assembly line. Since the width of the gap remains unchanged for all oven operating temperatures, manufacturing quality is controlled and improved, and desired oven baking characteristics are maintained consistently from oven to oven.

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

What I claim is:

1. A range comprising a sheet metal outer structure and an oven liner, said outer structure having a substantially vertical front wall and said front wall having a rectangular opening, said oven liner having a top wall, a bottom wall, side walls and a rear wall, said top, bottom and side walls having front marginal portions extending outwardly to provide top, bottom and side oven liner flanges, respectively, a horizontal strip member rigidly attached to the rear face of said lower liner flange and extending downwardly, said oven liner being disposed within and extending rearwardly of said opening and said strip member being attached to said front wall, said strip member thereby spacing said side flanges from said front wall, a support for said oven liner arranged to permit horizontal liner movement and a door forming a closure for said opening and said oven liner, said door being pivoted near its lower edge and having its upper edge adapted to abut said top liner flange.

2. A range comprising a sheet .metal. outer structure having a front wall, said front wall oven liner disposed within said opening and extending rearwardly therefrom, said oven liner I having its front marginal portion bent outwardly 5 a to provide a top flange and side flanges, said liner having means for spacing a substantial portion of said side flanges of the oven liner from said side flanges of the front wall, said means including a flat strip member at the bottom of the liner for securing the same to said bottom wall flange, and a pivotally mounted door adapted to register with said wall opening and close said oven liner, said door being spaced from said oven liner adjacent said pivotal 15 mounting.

3. The structure recited in claim 2 in which said strip member is formed integral with said liner and is offset rearwardly from the liner side flanges to effect said spacing.

EARL K. CLARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,478,134 Mitchell Dec. 18, 1923 1,669,803 Armstrong May .15, 1928 2,078,840 Dorl Apr. 27, 1937 2,367,007 Cossin Jan. 9, 1945 2,393,879 Barnsteiner Jan. 29, 1946

Images