IE54739B1

IE54739B1 - Microwave oven with common wrap and cavity walls

Info

Publication number: IE54739B1
Application number: IE2658/83A
Authority: IE
Original assignee: Litton Systems Inc
Priority date: 1982-11-29
Filing date: 1983-11-14
Publication date: 1990-01-17
Also published as: DK543983D0; HK59488A; DK161481B; EP0110364B1; KR840007169A; AU576741B2; DK161481C; ZA838604B; IE832658L; AU2145483A; ATE25799T1; DE110364T1; CA1203580A; DK543983A; DE3370118D1; EP0110364A1

Abstract

A low-cost microwave oven construction wherein a single sheet of metal forms both the cooking cavity and the outer wrap. The cavity, components compartment (12), and front and back panels (16, 17) are joined by a continuous crimped seam to form a unitary oven construction.

Description

-ΙΑ- 10 MICROWAVE OVEN WITH CCMCN WRAP AND CAVITY WALLS Background of the Invention This invention relates to the construction of microwave ovens, 15 and especially to the construction of the oven cavity and outer wrap. Because of the need to contain microwave frequency energy in a controlled fashion, almost all microwave ovens heretofore known include a discrete, box-like element referred to as the cooking cavity, or simply cavity. The cavity was secured into seme kind of frame which 20 housed the remainder of the oven operating components, the entire assembly being enclosed in a decorative outer shell, called a wrap.

Because of keen competition in the marketplace, it is necessary that microwave ovens be constructed as economically as possible. One way to realize substantial manufacturing econocy is to combine the oven 25 cavity and outer wrap into a single element. The present invention teaches how such a combination may be accomplished, which cabined with other aspects of the invention provide a truly economical construction.

Sunroflry of the Invention Ihe present invention provides for the construction of a micro-30 wave oven having a cabined oven cavity and wrap. A single formed metal sheet is folded to form an oven cavity which simultaneously provides one side wall and a major portion of the top and bottom walls of the outer wrap. A component section is added to the cavity to complete the other side wall and the remaining portion of the top and bottom of 35 the wrap. A front and back panel are added to complete the construction. Ihe cavity portion as well as the front and back panels may all be assembled by crimping techniques, thereby eliminating the need for welding or other forms of fastening. -2- 5 4 7 3 9 X Brief Description of the Drawings In the drawings, Figure 1 is an exploded perspective view showing the microwave oven construction of the present invention.

Figure 2 is a perspective view of the assembled oven.

Figure 3 is an enlarged partial cross section taken at line 3-3 of Figure 2 showing a portion of the crisp seam.

Figure 4 is an enlarged cross section of the crisp seam shown in Figure 3.

Description of Preferred Embodiments 10 Referring to the drawings, the oven cavity 10 is formed from a single flat metal sheet which has been formed and folded to construct a generally box-like cavity. Hence the cavity 10 includes top wall 20, side well 21, bottcm wall 22 and side wall portions 23 and 24 each having flanges 18 and 19. After folding, side wall portions 23 and 24 15 are joined together along edge 26 by means of a crisp seam whereby the side wall portions are folded upon one another to form a secure folded seam of the type illustrated in Figures 3 and 4. An aperture 25 is provided in the side wall 24, over which is mounted a waveguide 15.

A cooponents compartment 12 consisting of a generally U-shaped 20 metal sheet having an access portion and flanges 13 and 14 is attached to the cavity element 10 by spotwelding along the flanges 13 and 14.

Back panel 17 and front panel 16 are now added to the cavity/ component coupartment assembly. The front panel 16 is initially spot-welded to the flanges 18. Ihe back panel 17 is initially spotwelded to 25 the flanges 19. A crisp seam is then farmed about the entire periphery of front panel 16 and back panel 17 crimping the front and back panels to the cavity element 10 and the component coapartment 12. After the crisping operation the microwave oven structure is shown in Figure 2 results. Ihe details of the crisp seam are shown in Figures 3 and 4.

After the electronic and other operating components of the micro wave oven have been assembled in cosponent compartment 12, an access panel (not shewn) is placed aver the component compartment 12 to close it. The access panel may be attached by means of temper-proof fasteners. A microwave oven door (not shown) is then mounted to a front panel 16 to complete the oven construction.

The metal sheet from which the cavity element 10 is formed can be finished and decorated as desired. Hence the exterior side of top wall 20 and side wall 21 may be painted sane chosen color or may be covered. -3- 1 with woodgrain vinyl. The interior side of the sene top wall 20 and side wall 21, as well as bottom wall 22 nay all be painted a different color, such as white, for the interior of the oven cavity. However it is important to note that the oven cavity and outer wrap are both 5 provided by the same single metal sheet and that there is no separate cavity and/or outer wrap portion. The exterior of component compartment 12 will of course be finished in the same manner as the exterior portion of the cavity element 10.

The construction described and illustrated provides for an 10 extremely simple microwave oven construction cccprising a very small nutber of individual parts. The use of the common cavity wall and outer wrap reduces the materials used in the oven and the construction complexity to a minimum, and the use of crisping techniques to assemble the components greatly reduces the labor required in assembly as corn-15 pared to previously known constructions.

Claims

1. 1. A combined microwave oven cavity and wrap comprising: (a) a first formed metal sheet folded into an open-ended box-like 5 10 1 2. cavity; (b) a second formed metal sheet attached to one side wall of said cavity to form a components compartment; (c) a first panel extending substantially across both said cavity and said components compartment forming an oven front, and, (d) a second panel extending substantially across both said cavity and said components compartment forming an oven bade; (e) said first and second panels being joined to said cavity and said components compartment along a continuous crimped seam to form a unitary assembly; whereby said first formed metal sheet forms both the cavity interior walls and portions of the outer erven wrap.

2. The structure of claim 1 wherein the ends of said first formed metal sheet are joined along a crimped seam.

3. A combined microwave oven cavity and wrap as claimed in claim 1, substantially as hereinbefore described with reference to or as illustrated in the accompaning drawings. BY: EXECUTIVE 27 Clyde Road, Ballsbridge, Dublin

4. AGENTS FOR THE APPLICANTS.