Microwave oven with improved door

Abstract: There is disclosed a microwave oven including a main body 10 constituting a cooking chamber 11; a door 50 having a pivot pin 57 and an upwardly-projected rod 59 adjacent to the pivot pin and serving to open and close a front opening 12 of the main body; and a hinge member 40 integrally formed to have a pivot hole 42 into which the pivot pin 57 is rotatably fitted, a stopper 44 formed to transversely come into contact with the rod 59, and a slit 48 for accommodating a flank 60 of the door when the door is opened to the maximum. The hinge member also includes a door-connection section 41, a body-connecting section 47, and an inclined section 45. Such an integrally-formed hinge member prevents the deformation of the hinge member and generation of a gap between the door and the main body of the microwave oven whereby the reliability of microwave ovens of being such a construction can be enhanced.

Description: The present invention relates to a microwave oven. More particularly, it relates to a microwave oven that includes a door with a hinge for allowing the door to be opened at a desired angle with respect to a main body of the microwave oven. EP 0,204,153 discloses an elastic hinge, particularly for oven doors of gas and electric cooking ranges. Figure 4 is an exploded-perspective view of a microwave oven with a conventional door. As shown in Figure 4, the conventional microwave oven includes a main body 10 which is separated into a cooking chamber 11 for providing a space for cooking foodstuffs and an electric component compartment 15 for accommodating various electrical components, a door 50 attached to the front side of the main body 10 so as to open and close the front opening 12, and an upper case 90 for protectively covering the internal components. The cooking chamber 11 includes a front wall 25 defining the front opening 12, a rear wall 27, upper and lower walls 21 and 23, and side walls 29R and 29L. A hinge 31 is pushed through a slot 26 of the front wall 25 and fastened to the upper-front corner of the upper wall 21 and the side wall 29L by the use of a fastening member (not illustrated), that allows the door 50 to pivot to the left of the main body 10. There is a similar lower hinge 31 pushed through a second slot 26. The door 50 consists of outer and inner doors 51 and 55. A glass plate 53 is interposed between the outer and inner doors 51 and 55 so as to let a user see the cooking procedures of foodstuffs and their conditions inside of the cooking chamber 11. There is a hinge pivot 57 inserted into a pivot hole 37 of the hinge 41 to pivot the door 50 thereon and a projection 58 serving as a stopper of the door 50 on one end of the inner door 55 corresponding to the hinge 31. On the front of the hinge 31 are provided the pivot hole 37 into which the pivot 57 of the door 50 is inserted for free rotation, and a downwardly-protruding section 32 formed on the lower side of the hinge 31 in order to limit the rotation of the door 50. The downwardly-protruding section 32 is designed to contact the projection 58 of the inner door 55 when the door 50 is opened. In such a microwave oven, however, a bracket 33 is spot-welded to the upper wall 21 of the main body 10, and this bracket 33 and the hinge 31 are joined together by the use of screws (not illustrated), which complicates the assembling processes of the microwave oven. Besides, the projection 58 of the inner door 55 comes into contact with the downwardly-protruding section 32 of the hinge 31 as the door 50 is opened, and the frequent use of the door 50 easily wears out the projection 58 or the downwardly-protruding section 32 so that the door 50 may no longer open in a correct position. The spot-welding technique which is employed to join the thin-plate bracket 33 and the upper wall 21 of the main body 10 together, causes the deformation of the bracket 33, and it is difficult to determine the proper mounting position of the hinge 31. When the door 50 is improperly joined to the main body 10 by the hinge 31 that is installed on the incorrect spot, a gap may be created between the door 50 and the main body 10 so that electromagnetic waves which are deleterious to the human body leaks out through the gap. To prepare a dish by using such a microwave oven, a user opens the door 50 of the microwave oven, and puts a foodstuff to be cooked in the cooking chamber 11 and then closes the door 50. Once the cooking is finished, the user opens the door 50 again and takes the finish dish out of the cooking chamber 11. Such frequent opening and closing operations of the door 50 are hard on its hinge member, and adversely affects the reliability of a microwave oven being of this known construction. In other words, repeatedly opening and closing the door induces the deformation of the hinge member that holds the door. The deformation of the hinge member entails a chink between the door and the main body of the microwave oven, and is apt to cause a leakage of electromagnetic waves through this chink created between the door and the main body. Moreover, when the downwardly-protruding section provided to the hinge becomes too abraded, the door cannot maintain the correct opening position, or when the door opens while passing by the slightly worn-out protruding section, the projection of the door or the downwardly-protruding section may act as an obstacle to closing of the door. According to circumstances, a crooked protruding section can make the opening and closing the door an impossible task. Accordingly, the present invention encompasses a microwave oven with an improved door that substantially obviates the problems due to limitations and disadvantages of the conventional art. It is an object of the present invention to provide a microwave oven with a door being of improved construction in which a hinge member of the door and a hinge supporting bracket are formed in one united body so as to reduce the number of assembling steps. It is another object of the present invention to provide a microwave oven having a door with an integrally-formed hinge that allows the door to be opened at a predetermined angle with respect to a main body of the microwave oven to exactly maintain the opening position of the door thereby. According to the present invention there is provided an apparatus as set forth in the appended claims. Preferred features of the invention will be apparent from the dependent claims, and the description which follows. By way of example, a specific embodiment of the invention will now be described, with reference to the accompanying drawings, in which :- Figure 1 is an exploded-perspective view of a microwave oven having a door being of advanced construction in accordance with an embodiment of the present invention; Figure 2 is an enlarged-perspective view of a hinge member of the door in accordance with the present invention; Figures 3A and 3B respectively illustrate the operating conditions of the door with the hinge member in accordance with the present invention; and Figure 4 is an exploded-perspective view of a microwave oven with a conventional door. Throughout the drawings and the specification, similar reference numerals denote similar elements. Moreover, redundant descriptions of features common between the conventional art and preferred embodiment of the present invention are omitted. Figure 1 depicts a microwave oven having a door being of improved construction in accordance with the present invention, and Figure 2 is an enlarged-perspective view of a hinge member of the inventive door of the microwave oven. The microwave oven includes a main body 10 which may be divided into a cooking chamber 11, an electric component-compartment 15, and a door 50 attached to the front side of the main body 10 so as to open and close a front opening 12 of the main body 10. The microwave oven also includes an upper case 90 which protectively covers the upper and side portions of the main body 10. The cooking chamber 11 includes upper and lower walls 21 and 23, front and rear walls 25 and 27, and side walls 29R and 29L. A door 50 of the microwave oven consists of an inner door 55, and an outer door 51 accommodating the inner door 55. The door also includes a pivot pin 57 that serves to allow the door 50 to turn thereon, and a rod 59 that sets limits to rotation of the door 50 on one end of the inner door 55. A hinge member 40 is fastened to the upper wall 21 of the main body 10 by the use of screws (not illustrated) and allows the door 50 to pivot to the left of the main body 10. As shown in Figure 2 which is an enlarged-perspective view of the inventive hinge member of the door, this hinge member 40 consists of a door-connection section 41 joined, in use, to the door 50, a body-connecting section 47 joined, in use, to the upper wall 21 of the main body 10, and an inclined section 45 interposed between the door-connection section 41 and body-connecting sections 47. An angle of inclination at which the inclined section 45 is formed is determined enough to facilitate insertion of the hinge member 40 into a slot 26 provided on the front wall 25 of the main body 10. The door-connection section 41 of the hinge member 40 is designed to be higher with respect to the body-connecting section 47 so that the door-connecting section 41 can be joined to the pivot pin 57 of the door 50. The door-connecting section 41 has a pivot hole 42 into which the pivot pin 57 is inserted for free rotation, and a stopper 44 which restricts the action of the rod 59. The door-connecting section 41 also includes a slit 48 that can accommodate a flank 60 of the door 50 that will be discussed later to facilitate the movement of the door 50, and an embossed portion 46 for reinforcing the door-connecting section 41. The body-connecting section 47 of such a hinge member 40 is pushed through the slot 26 of the front wall 25 and this body-connecting section 47 is then fixed onto the upper wall 21 of the main body 10 by the use of screws (not illustrated). Subsequently, the pivot pin 57 of the door 50 is rotatably fitted into the pivot hole 42 of the door-connecting section 41 sticking out from the slot 26 toward the door 50. Once a push button provided on the control panel 17 is pressed, while the door 50 rotatably joined to the main body 10 by the integral hinge member 40 is in the closed position, closing the front opening 12 of the main body 10, the door 50 formed to be pivoted on the main body 10 comes to be opened on the pivot pin 57. After foodstuffs to be cooked are put on a tray of the cooking chamber 11, the front opening 12 of the cooking chamber 11 is closed with the door 50, and the cooking is then carried out. Once the cooking is finished, the door 50 is opened in the above-mentioned manner, and the finished dish is taken out from the cooking chamber 11 and the door 50 is closed again. Figures 3A and 3B respectively depict the opened and closed states of the door 50. As depicted in Figure 3A, when the door 50 is being closed, the rod 59, that is formed to upwardly protrude on the upper part of the door 50, moves away from the stopper 44 of the hinge member 40, joined to the upper wall 21 of the main body 10, and the flank 60 of the door 50 slips out of the slit 48 of the hinge member 40. When a user presses the push button of the control panel 17 to open the door 50, the door 50 turns to the outside on the pivot pin 57 that is supported by the hinge member 40. As shown in Figure 3B, if the door 50 is opened to the maximum, the slit 48 of the hinge member 40 accommodates the flank 58 of the door 50 to thereby prevent the flank 60 from hindering the rotation of the door 50. The rod 59 of the door 50 comes into contact with the stopper 44 of the hinge member 40 in such a manner that the door 50 is not opened any further and the door 50 and the hinge member 40 are free from deformation. According to the present invention, the hinge member of the door is designed to be one component and can be easily and promptly joined to the main body of the microwave oven whereby the number of the assembly steps of a microwave oven with the inventive door can be decreased. Further, the rotation supporting member that serves to maintain the opening position of the door is provided to the door and the hinge member so that the reliability to the door of the microwave oven can be enhanced. Still further, the hinge member of the present invention which supports the door of the microwave oven is integrally provided on the upper wall of the main body, and such a construction prevents the deformation of the hinge member and creation of a gap between the door and the main body of the microwave oven, which ensures an enhanced reliability of microwave ovens of being such a construction. Although only one hinge member 40, and its operation, have been described in detail, it will be appreciated that there are upper and lower members 40, at the top and bottom of the door respectively. The preferred embodiment of the present invention are given by way of example, and the invention recited in the attached claims is not limited to the illustrative embodiment. Those of ordinary skill in the art will recognize that routine design changes may be made to the exemplary embodiment without departing from the scope of the claims.

Claims: A microwave oven comprising: a main body (10) constituting a cooking chamber (15); a door (50), having a pivot pin (57) and a projection (59) adjacent to said pivot pin, for use in opening and closing a front opening of said main body (10); and a hinge member having a pivot hole (47) into which said pivot pin (57) is rotatably fitted; and stopping means (44) formed to come into contact with said projection (59) ; characterised by : the hinge member (40) having a plate portion, the thickness of the plate portion serving as said stopping means. A microwave oven according to claim 1, wherein the hinge member (40) is integrally formed. A microwave oven according to claim 1 or 2, wherein the hinge member comprises: a door connecting section (41) arranged in use to connect to the door (50); a body connecting section (47) arranged in use to connect to the body (10); and an intermediate section (45) interposed between the door connecting section (41) and the body connecting section (47). A microwave oven according to claim 3, wherein the door connecting section (41) is arranged to be higher with respect to the body connecting section (47). A microwave oven according to claim 3 or 4, wherein the intermediate section (45) is inclined between the door connecting section (41) and the body connection section (47). A microwave oven according to any of claims 1 to 5 wherein said hinge member (40) includes means for accommodating a flank (48) of said door (50) when said door is opened to the maximum. A microwave oven according to claim 6, wherein the means for accommodating said flank (48) comprises a recess. A microwave oven according to any one of the preceding claims, in which the projection (59) comprises an upwardly projecting rod which comes into contact with the stopping means (44) when the stopping means (44) moves transversely as the door opens.

Inventors: HWANG YUN IC, HWANG, YUN IC
Applicants: SAMSUNG ELECTRONICS CO LTD, SAMSUNG ELECTRONICS CO., LTD.
Application year: 1996
Main classification: H05B6
IPC codes: F24C15, F24C7, H05B6