Abstract: A towel rack has two mounting base each having multiple sockets, multiple extension rods, multiple extension tubes and multiple optional connectors. The multiple extension rods are engaged the sockets to secure between the two bases. Each base has an upper and lower arms radially extending from the base and the upper arm especially has a raised distal end engaged one extension rod to keep objects stacked on the towel rack from falling. Moreover, the multiple extension tubes are attached between the two bases by the connectors mounted on the upper arms of the bases. Therefore, the towel rack has an excellent facility in use and is easy to be assembled.

Abstract: A merchandise display implement used while being hooked on a frame bar, including an opening portion capable of housing merchandise in a condition of rowing the same, a hanger portion to be hooked on the frame bar, and a supporting leg capable of being mounted on a plane surface is constructed. Even though a shelf or a board is not provided, the merchandise can be displayed in a plane-surface manner when only the frame bar is installed on a wall in a shop. Further, since the merchandise can also be mounted on a plane surface by a supporting leg, the merchandise can also be displayed on a board, a shelf, or the like. Furthermore, only by engaging a hook with a hook engaging hole, the merchandise can also be displayed in a condition in which a plurality of merchandise display implements is connected to each other.

Abstract: A display apparatus for holding a plurality of items and including a base and at least one shelf divider is disclosed. The base includes a front end, a back end, a left end, a right end, and an upper surface for supporting the items. The shelf divider is removably installable on the base and defines at least one channel dimensioned for accommodating an associated column of the items. The shelf divider includes a top surface, a bottom surface, a front edge, a rear edge and at least one compliant member depending from the bottom surface. The compliant member is deflectable towards the top surface upon engagement with a portion of the base.

Abstract: A merchandise display system includes a base-and-divider assembly. The base-and-divider assembly includes a base portion adapted for operative coupling to a front rail, and a divider portion for dividing displayed merchandise into rows. The divider portion protrudes from the base portion such that the divider portion separates the base portion into a first portion and a second portion. A spring-urged pusher is mounted to a pusher track for pushing merchandise toward the front of a shelf. A retaining wall curves inwardly from a front edge of the divider portion along at least a portion of the first portion.

Abstract: A rack truss for use in forming shelf-type storage racks which may be assembled at the site using bolts and/or which includes reinforcement at the lower level of the rack truss.

Abstract: Opposed walls of three hingedly attached grid walls are secured to one another by a first strap having folded back ends for partially encircling a segment of a wire element of each opposed grid wall. A second strap is placed adjacent the first strap with the ends of the second strap bearing against the partially encircled wire elements to retain the wire elements within the respective folded back ends. Nylon ties or bolts may be used to secure the first and second straps to one another. Two or more pairs of first and second straps support a grid wall serving as a shelf and the shelf may be secured to the straps by pairs of nylon ties. To provide mobility to the display rack, fixed or pivotable wheels are supported by the lowermost pairs of first and second straps and may be secured thereto by nylon ties or by nut and bolt combinations. A billboard unit having four panels is formed by two three-segmented panels placed orthogonally upon one another to permit upward bending of the pairs of outer panels.

Abstract: A base for supporting an upstanding post having a first base member and at least one second base member. The first base member includes a first socket portion and a first support portion. Each second base member includes a second socket portion and a second support portion. The first and second base members are connected to each other and the first and second socket portions together define a post socket. The post socket has a plurality of walls defining a perimeter and extending from a bottom support for surrounding an end of the upstanding post. The first and second support portions each include at least one bearing point remote from a respective one of the socket portions to engage a support surface. A sports equipment rack and a kit for an assembly of a sports equipment rack is also disclosed.

Abstract: [PROBLEMS] To provide a rotating frame of an upper rotating body such that total productivity can be improved, the cost can be reduced, and model change can be facilitated. [MEANS FOR SOLVING PROBLEMS] Many models having different lifting capacities are divided into a plurality of classes each including a plurality of models. A rotating frame 17 is determined on the basis of the model having the largest lifting capacity in each class. An upper rotating body is constructed using the rotating frame 17 as the base. In addition, each of winches 5 to 7 is mounted on the rotating frame by using a mounting structure standardized in the same class. On the other hand, left and right deck frames 18 and 19 are divided into sections on which different pieces of equipment are mounted, and the sections are separately attached to the rotating frame 17.

Abstract: The present disclosure relates to a telescopable sliding beam comprising a sliding beam box and at least one first and one second sliding beam, which are telescopable into each other, the first sliding beam being mounted in the sliding beam box such that it can be telescoped out, where at first the first sliding beam can be telescoped out, and after the same has telescoped out to a desired point, the second sliding beam can be telescoped out, whereas during backward retraction, the second sliding beam can first be retracted to a desired point and subsequently the first sliding beam can be retracted.

Abstract: A towing arrangement intended for train couplers includes a bar (8), which at a rear end has an axially projecting pin (10), which projects through a through hole (40) in a plate (11), which on both sides is surrounded by shock-absorbing spring members (12), which always aim to hold the pin in a starting position in relation to the plate, and against the action of which the pin together with the bar are axially movable. The plate (11) is included in a mandrel (16) equipped with a cone (19), which mandrel is inserted into a deformation tube (17), more precisely into a wide, front tube section (22), which via a waist (23) transforms into a thinner, rear tube section (21), which is deformable by the mandrel (16). A deformation tube is also described.

Abstract: A removable cap assembly having a cap with a curved side wall having an inner surface and an outer surface. A top portion extends from the side wall. A boss extends perpendicularly from the top portion in the shape of an inverted trapezoid, where the boss has a bottom and a top. A first circumferential rib extends perpendicularly from the top of the boss. A stopper is dimensioned to seal the opening, having an inverted trapezoidal shape complementary to the boss. The stopper is maintained in the cap by the inverted trapezoid shape of said boss. The stopper includes a disc shaped base, a cylindrical wall portion extending from the base, a first groove in the base surrounding the wall portion dimensioned to receive the bottom of the boss. An appliance member is adapted to be positioned within the hole and extending through the opening.

Abstract: The invention relates to a scaling cap (1) that is to be screwed and/or pressed onto the pouring neck (4) of a container, especially a bottle. Said sealing cap (1) comprises a particularly annular coaxial sealing lip (6) which is fixed within the bottom (2) of the cap and extends into the neck when the cap is mounted. The sealing lip is curved and/or buckled towards the outside between the upper and the lower end (7, 8) thereof in such a way that the curvature (12) and/or the buckled point (9) travel/s further out and the external face of the sealing lip sealingly rests against the interior wall of the neck when the sealing lip is compressed in an axial direction.

Abstract: A blow-molded plastic container includes an upper portion having a finish, a body portion and a base. At least one groove is formed in a radial sidewall of the finish. The groove slopes gradually downward along the radial sidewall and away from an opening into the container. A method of making the blow-molded plastic container includes disposing a preform into a mold cavity having a surface defining a body forming region, a finish forming region and a moil forming region. The preform is blown against the mold surface to form an intermediate container having a body portion, a finish and a moil portion. The moil is severed from the finish to define the opening into the container. A closure member is adapted to selectively mate with the finish on the container. At least one thread is formed on the closure member.

Abstract: A finish for a plastic container and a preform adapted to be molded into the plastic container. The finish and the preform include an upper portion having a mouth defining an opening into the container. At least one groove is defined around a radial sidewall of the upper portion. The groove slopes gradually downward along the radial sidewall to a terminal end.

Abstract: The present invention provides a method and an apparatus for reducing, or eliminating, the notching observed in the creation of SOI structures on a substrate when plasma etching through an alternating deposition/etch process by modulating the RF bias that is applied to the cathode. Modulation of the bias voltage to the cathode is accomplished either discretely, between at least two frequencies, or continuously during the alternating deposition/etch process.

Abstract: A decorative surface treatment of hardenable metals to achieve a three dimensional textured surface with the appearance of mokume gane or Damascus steel. The annealed surface of the metal is selectively hardened by a laser in zones next to unhardened areas. The unhardened areas are selectively eaten away by abrasives in a way that allows deep texture relief.

Abstract: Methods for post-etch deposition on a dielectric film are provided in the present invention. In one embodiment, the method includes providing a substrate having a low-k dielectric layer disposed thereon in a etch reactor, etching the low-k dielectric layer in the etch reactor, and forming a protection layer on the etched low-k dielectric layer. In another embodiment, the method includes providing a substrate having a low-k dielectric layer disposed thereon in an etch reactor, etching the low-k dielectric layer in the reactor, bonding the etched low-k dielectric layer with a polymer gas supplied into the reactor, forming a protection layer on the etched low-k dielectric layer, and removing the protection layer formed on the etched low-k dielectric layer.

Abstract: A method for forming self-assembled patterns on a substrate surface is provided. First, a block copolymer layer, which comprises a block copolymer having two or more immiscible polymeric block components, is applied onto a substrate that comprises a substrate surface with a trench therein. The trench specifically includes at least one narrow region flanked by two wide regions, and wherein the trench has a width variation of more than 50%. Annealing is subsequently carried out to effectuate phase separation between the two or more immiscible polymeric block components in the block copolymer layer, thereby forming periodic patterns that are defined by repeating structural units. Specifically, the periodic patterns at the narrow region of the trench are aligned in a predetermined direction and are essentially free of defects. Block copolymer films formed by the above-described method as well as semiconductor structures comprising such block copolymer films are also described.

Abstract: A method of etching a feature in a surface of a substrate. The substrate is provided. A photoresist layer is formed on the surface of the substrate. A thickness profile of the formed photoresist layer is determined. A grayscale scanning pattern is determined based on the feature and the thickness profile of the photoresist layer. The determined grayscale scanning pattern is laser written on the photoresist layer to expose a portion of the photoresist layer. The exposed portion of the photoresist layer is removed to form a grayscale pattern in the photoresist layer. The photoresist layer and the surface of the substrate are etched to form the feature in the surface of the substrate.

Abstract: A plasma processing system for processing a substrate is disclosed. The plasma processing system includes a gas distribution system. The plasma processing system also includes a gas flow control assembly coupled to the gas distribution system and configured to control a set of input gases provided by the gas distribution system. The plasma processing system further includes a first set of nozzles coupled to the gas flow control assembly and configured to supply a first set of gases for processing a first portion of the substrate. The plasma processing system further includes a second set of nozzles coupled to the gas flow control assembly and configured to supply a second set of gases for processing a second portion of the substrate.

Abstract: An anisotropic etching agent composition for manufacturing of micro-structures of silicon comprising an alkali compound and hydroxylamines; an anisotropic etching method with the use of the etching agent composition. The alkali compound is preferably tetramethylammonium hydroxide, and the hydroxylamines is preferably at least one kind selected from the group consisting of hydroxylamine, hydroxylamine sulfate, hydroxylamine chloride, hydroxylamine oxalate, dimethyl hydroxylamine hydrochloride and hydroxylamine phosphate. An anisotropic etching property whose etching rate is different in crystal face orientation especially relating with etching technology with the use of manufacturing of micro-structures of silicon used as Micro Electro Mechanical Systems (MEMS) parts, semiconductor materials, etc is provided.

Abstract: An object of the present invention is to provide a single wafer etching apparatus realizing a high flatness of wafers and an increase in productivity thereof. In the single wafer etching apparatus, a single thin disk-like wafer sliced from a silicon single crystal ingot is mounted on a wafer chuck and spun thereon, and an overall front surface of the wafer is etched with an etching solution supplied thereto by centrifugal force generated by spinning the wafer 11. The singe wafer etching apparatus includes a plurality of supply nozzles 26, 27 capable of discharging the etching solution 14 from discharge openings 26a, 27a onto the front surface of the wafer 11, nozzle-moving devices each capable of independently moving the plurality of supply nozzles 28, 29, and an etching solution supplying device 30 for supplying the etching solution 14 to each of the plurality of supply nozzles and discharging the etching solution 14 from each of the discharge openings to the front surface of the wafer 11.

Abstract: As part of a system for processing workpieces, a workpiece support arrangement, separate from a process chamber arrangement supports at least two workpieces at least generally in a stacked relationship to form a workpiece column. A transfer arrangement transports at least two of the workpieces between the workpiece column and the process chamber arrangement by simultaneously moving the two workpieces at least generally along first and second transfer paths, respectively, that are defined between the workpiece column and the first and second process stations. The transfer arrangement can simultaneously move untreated and treated workpieces. Vertical motion swing arms and coaxial swing arms are described. A pair of spaced apart swing arms, the workpiece column and the processing stations can cooperatively define a pentagonal shape. Timing belt backlash elimination, a dual degree of freedom slot valve and low point chamber pumping, for removing chamber contaminants, are also described.

Abstract: A process for the fabrication of an inertial sensor with failure threshold includes the step of forming, on top of a substrate of a semiconductor wafer, a sample element embedded in a sacrificial region, the sample element configured to break under a preselected strain. The process further includes forming, on top of the sacrificial region, a body connected to the sample element and etching the sacrificial region so as to free the body and the sample element. The process may also include forming, on the substrate, additional sample elements connected to the body.

Abstract: A vacuum insulated switchgear comprising a case having a switch section, a bus-bar section and a cable section, each being partitioned by an earthed metal plate, a vacuum double break three point switch disposed in the switch section and having breaking and disconnecting function, an operator, a bus-bar disposed in the bus-bar section of the case, and a cable connection terminal connected to a cable in the cable section.

Abstract: A method of improving a single-sided resistance spot weld includes forming an adhesive bond between a sheet and a tube to thereby form a two-ply structure by which the sheet metal and the tube wall stiffen each other against bending. The adhesive bond is preferably formed by heat curable adhesive and the adhesive is partially cured by applying the electrode to a spot on the sheet and then conducting current through the electrode to induce electric resistance heating in the sheet and tube to cure the adhesive. After the adhesive bond is formed, the electrode is moved to a new spot on the sheet and then forcibly applied against the stiffened sheet and resistance welding current is applied through the electrode to form a resistance spot weld between the stiffened sheet and the stiffened tube wall.

Abstract: A resistance spot welding system (10) for sequentially clamping a plurality of workpieces (20,22) at predetermined locations and welding the workpieces (20,22) substantially adjacent the locations, including a clamping element (24) able to be locked in a workpiece engaged position, at least one set of equalizing welding electrodes (28,30) for oppositely engaging the workpieces (20,22) so as to produce the weld (12) without deformation, a singular drive mechanism (14) including a cam coupled to the clamping element (24) and electrodes (28,30), and a singular source (16) for actuating the mechanism (14) and generating the welding and clamping forces.

Abstract: A method for monitoring a resistance welding process carried out on a stack of metal workpieces (1) clamped between two electrodes (2a, 2b) of a clamp (3), and a device therefor. According to the method, the electrodes (2a, 2b) are subjected to a clamping force (F) and a voltage (V(t)) enabling a current (I(t)) to flow through the stack of metal workpieces (1). The monitoring method further includes at least one step of analysing the clamping force (F) by comparison with a model from a prior learning process. The result of the analysis of each step is taken into account by a decision-making matrix to generate a correction and/or control signal intended for the welding process.

Abstract: An improved collimator for a plasma arc torch consists of an annular holder member and an insert member. The insert member includes a tubular stem portion ending in an integrally formed, radially extending face plate. When the stem portion is fitted into the central bore of the holder member with a predetermined clearance fit therebetween, a cooling water passage is created. The improved collimator is characterized by the absence of any welds between the holder member and the insert member that would be exposed to conductive gases given off during use of the plasma arc torch and a lesser resistance to cooling water flow than prior art collimator designs.

Abstract: This application relates to a plasma torch assembly comprising a plurality of tubes; a collar integral with at least one tube comprising a first abutment surface; a base for holding the tubes during operation of the torch comprising a portion for receiving the collar and a second abutment; and co-operating interlocking portions for removably urging the first and second abutment surfaces together by relative rotation of the interlocking portions wherein the first and second abutment surfaces comprise a complimentary taper for aligning the collar in concentric formation with at least one other tube on the base by co-operation of the interlocking portions.

Abstract: Methods of preventing ablation damage to a second wall or an underlying second article during the laser drilling of a first wall or an overlying first article are presented. The methods include a step of providing a dry, stable particulate material between the first and second walls or articles to shade the second wall or article from direct laser beam illumination during the laser machining of the first wall or article.

Abstract: A weld zone of T-piping and its neighborhood are efficiently laser-heated to remove residual stress. For this purpose, the weld zone of a T-piping (50) is irradiated and heated with a laser beam emitted from a laser head (10) to remove residual stress. At this time, a rotating travel cart (3) travels along a ring rail (2) to adjust the position of the laser head (10) in a ?-direction, a vertical slide (4) slides to adjust the position of the laser head (10) in a Z-direction, a radial slide (5) slides to adjust the position of the laser head (10) in an L-direction, an arcuate piece slide (7) slides along an arcuate piece to adjust the ?-direction of the laser head (10), a laser head support portion (9) turns to adjust the ?-direction of the laser head (10), and oscillation adjusts the position of the laser head (10) in a ?-direction.

Abstract: An automated welding system is provided for welding a workpiece. The system includes a multiaxially movable arm, a fiber optic cable, a laser source, a focusing head, a focus lens, and a shield. The fiber optic cable is coupled to the arm. The laser source is coupled to the fiber optic cable and configured to supply laser light thereto. The focusing head includes a first end, a second end, and a passage extending therebetween. The shield has an inlet, an outlet and a cavity formed therebetween, and each of the inlet and the outlet has a diameter. The shield inlet is coupled to the focusing head and the shield inlet diameter is greater than the shield outlet diameter. The shield outlet diameter is sized to provide an opening through which the laser beam exits and prevents substantially all particles external to the focusing head passage from entering therein.

Abstract: The invention relates to a method, which is used to produce sets of control data for the production of metallic and/or non-metallic products 2, 21 by free-form sintering and/or melting by means of a high-energy beam (8), in particular a laser beam or electron beam, whereby a product 2, 21 is built up, layer by layer 12 to 15, 20, 22, out of a material 6 that is to be spread out in layers, by means of said beam 8, which is guided with the help of a control data set, whereby the method comprises the steps of loading 23 a product target geometry data set that represents the target geometry of the product to be produced and of generating 25 the control data set on the basis of the product target geometry data set.

Abstract: A welding method for gas metal arc welding is provided with continuous electrode feeding and control for short arc welding and/or spray arc welding and also short pulsing in which the control cyclically alternates between short pulsing and short arc or spray arc welding, and time for carrying out the respective control being programmed by a user. A welding power source and software for carrying out this method are also provided.

Abstract: A weld wire for storage on a spool of weld wire, a method for making same, and an article of manufacture including a weld wire carried on a spool. The weld wire has a substantially linear cast in the form of an undulating curve including a succession of generally semi-circular sections having a generally fixed mean average radius of curvature of about 200 inches but not less than 80 inches. In one form, the cast has a radius of curvature in the range of about 100-300 inches. The linear cast is formed on the weld wire prior to the weld wire being wound onto the spool of weld wire. The linear cast is at least partially retained on the weld wire after the weld wire is unwound from the spool and during the feeding of the weld wire through a welding machine. The spool includes a hub portion having a diameter in the range of about 18-20 inches for carrying weld wire having a diameter in the range of about 0.035-0.062 inches.

Abstract: A floor heating system including a sub-floor, a plurality of fasteners, a first heater conductor assembly and a second heater conductor assembly. The first conductor assembly including a first resistive conductor having a first length, first and second ends, and two low resistance conductors. The two low resistance conductors being respectively connected to each of the first and second ends. The second heater conductor assembly including a second resistive conductor having a second length, first and second ends, and two low resistance conductors. The two low resistance conductors being respectively connected to each of the first and second ends of the second resistive conductor. The low resistance conductor that is connected to the first end of the first resistive conductor being connected in a serial fashion to the low resistance conductor that is connected to the first end of the second resistive conductor. The first length being approximately a first integer multiple of the second length.

Abstract: A floor heating system including a sub-floor, a plurality of fasteners, at least one resistive conductor and a capacitor. The at least one resistive conductor is fastened to the sub-floor by way of the plurality of fasteners. The capacitor is electrically in series with the at least one resistive conductor.

Abstract: The fixing apparatus of an image forming apparatus has a heating device, a feeding device and control device, wherein in a case of continuously forming images onto the material to be heated, wherein the control device changes the turn-on time ratio in accordance with a size of the material to be heated and determines the feeding timing of the material to be heated fed by said feeding device in accordance with temperature distribution of the heating device in a longitudinal direction of the heating member perpendicular to a conveying direction in which the material to be heated is conveyed. It can suppress the occurrence of wrinkles and can improve a throughput.

Abstract: An electric hair curler is disclosed as including a handle; and a heating tube engaged with the handle and having a longitudinal axis, and the heating tube is adapted to be releasably engaged with hair and is operable to heat hair engaged therewith, and the heating tube is rotatably movable relative to the handle about the longitudinal axis of the heating tube.

Abstract: A laser guided work device including a work board having a work surface, a line producing laser projecting a line on the work surface, and a linear motion device engaging the laser to the work board. The linear motion device translates the laser relative to the work surface along at least one dimension. The line is oriented perpendicular to the at least one dimension such that the line moves relative to the work surface when the linear motion device translates the laser along the at least one dimension.

Abstract: A control system for an electric water heater having an upper heating element and a lower heating element is disclosed. The control system includes a control module that controls operation of the electric water heater by selectively toggling the upper and lower heating elements between an ON state and an OFF state and a consumer interface module that allows a consumer to input a set point temperature and select an energy savings mode for the electric water heater. The control module regularly monitors hot water usage and adjusts the set point temperature by a predetermined setback amount until a capacity of the water heater matches consumer usage.

Abstract: A steam cooker includes a steam cooking chamber including left, right, top, bottom and rear walls, a front access opening and a door moveable between an open position to allow access to the steam cooking chamber and a closed position to inhibit access to the steam cooking chamber through the access opening. A steam inlet path extends through one of the cooking chamber walls. A stationary nozzle unit is located within the cooking chamber and alongside the one of the cooking chamber walls for receiving steam from the steam inlet path. The nozzle unit includes multiple steam delivery nozzles disposed at stationary positions relative to the one of the cooking chamber walls. The multiple steam delivery nozzles are arranged and configured to emit steam substantially parallel to the one of the cooking chamber walls.

Abstract: A steam oven construction and method of assembly utilizing a modular cavity unit is described.

Abstract: A slow cooker for heating of food stuffs includes a container having a generally hollow interior and a container rim defining an opening for accessing the interior. The interior is capable of retaining the food stuffs therein. A first base for supporting the container has an electric heating element, which is selectively powered to heat the container and the food stuffs therein. A second base for supporting the container accommodates a flame heater therein for heating the container and the food stuffs therein. The first and second bases are alternatively used to heat the container.

Abstract: A confectionary fountain assembly enables user to self-serve confectionary liquid, such as liquid chocolate. The fountain assembly comprises a base assembly, a conduit assembly, a functional sculpture, and an annular basin. The base assembly supports a bowl-shaped receptacle and houses a heating element and a motor assembly for respectively providing chocolate-liquefying thermal energy and rotational movement. The conduit assembly is coupled to the motor assembly and the receptacle and comprises a liquid chocolate lifting auger. The sculpture assembly receives the lifted chocolate and imparts pressure thereto for further directing the chocolate to a sculpture outlet. The chocolate, upon exiting the outlet, covers an outer decorative surface of the sculpture and returns to the receptacle.

Abstract: Disclosed are apparatus and methodology for reducing the chances of a fire during the operation of heating or cooking appliance. Motion sensitive circuitry incorporated into control circuitry for the appliance monitors activity near the appliance. If activity near the appliance is not detected within a preselected time period, heat producing elements associated with the appliance are disengaged. A manual override mechanism may be provided to permit longer term use of the appliance, as special occasions require.

Abstract: The invention relates to a heater panel of a radiant heater comprising a heating spiral provided on a panel element and mechanically connected to the panel element with a portion of a spiral turn. With the object of providing a heater panel with a stable arrangement of the heating spiral on the panel element by which a high power density is achievable, each spiral turn is detachably connected to the panel element by three spaced-apart contact spots. Two of said contact spots are located on the outer circumference of the spiral turn in such a distance to each other that the radii originating at them define an angle of less than 180°, and the third contact spot is located on the inner circumference of the spiral turn within the portion of the spiral turn facing the panel element and confined by the two outer contacts.

Abstract: A purpose of the present invention is to provide an inverter circuit capable of firmly turning ON IGBTs under limited condition, while a heat loss and noise can be hardly produced in semiconductor switching elements.

Abstract: The object of the invention is to improve the safety of a cooking apparatus, the efficiency of the door opening and shutting operation of the door opening and shutting part, and the quality of a cooked food. An opening and shutting door 4 includes a handle 5 for opening and shutting the door, and a door key 11 removably mounted on the door and including engaging portions 11a and 11b provided on two portions of the door key spaced a given distance from each other and projected toward the heating chamber side. In the interior of a cooking apparatus main body, there is provided a door hook 13 which, in the door shut state, is engaged with the engaging portions 11a and 11b inserted to thereby hold the door key 11. The door hook 13 includes door switches 14 and 16 which, when they are contacted with the engaging portions 11a and 11b, can be respectively switched so as to allow a power supply circuit for heating to conduct.