Abstract For the prevention of wave leakage from within a chamber of a high-frequency sealing device such as a heating device (especially one for food-processing applications), there is provided a hollow metal door having a resilient inner surface for leakageproof contact with the inner edges of the open end of the chamber. A leaking wave, if any, from between the inner surface of the door and the inner edges of the heating chamber is guided into the hollow interior of the door through an elongated window provided on the inner surface thereof. The door may contain a dielectric for absorption of the leaking wave, and its window may be permanently closed with a dielectric thereby to prevent the entrance of any extraneous matter (e.g., water and dust) into the door interior without rendering the window itself impervious to the leaking wave.
A high-frequency sealing device comprising a main body in which is provided a heating chamber having a front opening and a door for closing said opening, said door comprising an inner metal plate resiliently contacting the periphery of said opening and another metal plate spaced apart from said inner plate, the peripheral edge of said other plate being bent inwardly into the shape of a letter U, thus forming an annular cavity in said Ushaped peripheral edge, characterized in that said contact between the periphery of said front opening and said inner metal plate is direct metal-to-metal contact, that at least one opening is formed between said contact and the peripheral sidewall of said other plate at a distance of lambda /4 from said contact, and that the distance between the center of said opening and said other plate is up to lambda /4.
Claim 2
Dependent Claim
144 words
A high-frequency sealing device comprising a main body in which is provided a heating chamber having a front opening and a door for closing said opening, said door comprising an inner metal plate resiliently contacting the periphery of said opening and another metal plate spaced apart from said inner plate, the peripheral edge of said other plate being bent inwardly into the shape of a letter U, thus forming an annular cavity in said Ushaped peripheral edge, characterized in that said contact between the periphery of said front opening and said inner metal plate is direct metal-to-metal contact, that at least one opening is formed between said contact and the peripheral sidewall of said other plate at a distance of lambda /4 from said contact, and that the distance between the center of said opening and said other plate is up to lambda /4.
Claim 3
Dependent Claim
30 words
A high-frequency sealing device accorDing to claim 1 wherein a dielectric material is contained in the space between said inner and other plate, said space including at least said cavity.
Claim 4
Dependent Claim
14 words
A high-frequency sealing device according to claim 2 wherein said dielectric material is resilient.
Claim 5
Dependent Claim
34 words
A high-frequency sealing device according to claim 1 wherein a conductive plate is inserted between said inner and outer plate at a point lambda /2 apart from the bottom wall of the outer plate.