MXPA06009168A - Electrical evaporator with ratcheting wick adjuster - Google Patents

Abstract

An evaporator (10) includes a housing (100, 200), a bottle (400) containing a substance to be evaporated, a wick (500) protruding from the bottle (400), a rotatable plug deck (300) for providing electricity to the evaporator (10), a heating device (250) disposed within the housing (100, 200), and an adjuster (600) within the housing (100, 200) for displacing the wick (500) toward or away from the heating device (250). The adjuster (600) includes a retaining mechanism (650) that retains the adjuster (600) in a selected one of a plurality of discreet adjustment settings. The plug deck (300) includes a locking mechanism (340, 342) that retains the plug deck (300) in a selected one of a plurality of discreet positions.

Description

ELECTRIC EVAPORATOR WITH DATED WELD ADJUSTER Field of the Invention The invention relates generally to an electric evaporator for use with liquid formulations containing a chemical active ingredient, such as an insecticide, a fragrance, an odor eliminator or the like and, in particular, an electric evaporator that it has an aspect of adjustable intensity that allows to vary the evaporation rate of the liquid formulation between a minimum level and a maximum level. BACKGROUND OF THE INVENTION Electric evaporators are known in which the evaporation rate of a liquid formulation can be adjusted from a wick by varying the relative positions of a heating device and the wick. For example, the Spanish utility model No. 1 005 422 describes an evaporator in which a heating device and a wick can be moved vertically, one with respect to the other, by means of a mechanical device, such as a screw threaded mechanism. / nut, in order to increase or decrease the intensity of the heat to which the wick is exposed. European Patent Publication No. 0 942 648, in contrast, discloses an evaporator in which a heating device remains stationary, while a wick and a bottle are displaced vertically in the direction of the longitudinal axis of the wick, using a threaded mechanism. screw / nut, which increases or reduces the overlap between the wick and the heating device. Another type of evaporator is described in European Patent Publication No. 0 943 344. In that evaporator, a heating device is mounted on a plug that moves in approach or away from a wick. U.S. Patent Publication No. 2003/0138241 A1 ("the publication '241"), which is incorporated herein by means of this reference, still discloses another type of evaporator having an adjuster for displacing the portion of a wick in approach or moving away from a heating device, in a direction substantially perpendicular to the longitudinal axis of the wick. Several perceived drawbacks of these adjustable evaporators are that they are difficult to adjust in discrete intervals and that the repeatability of the adjustment is difficult. In addition, some types of plug-in appliances, particularly wick-based evaporators, should be used in a vertical orientation, in order for them to function properly. Because some electrical outlets are vertical (ie, one receptacle is on top of another), while other receptacles are horizontal (ie with receptacles side by side) it is preferable that these appliances have a rotating plug, which allow the device to be used in both vertical and horizontal outputs. U.S. Patent No. 5,647,053, which is also incorporated herein by way of this reference, discloses a wick-based evaporator having a rotary plug. A perceived drawback of this type of evaporators is that it is difficult to tell when the plug is in an appropriate position to use it. In addition, evaporators of this type have no provision for securing the plug in the positions of use. BRIEF DESCRIPTION OF THE INVENTION The present invention remedies these deficiencies and others of the prior art, and provides an electric evaporator having an improved adjuster for rapidly and easily varying the evaporation rate of the liquid formulation, and an improved rotary plug assembly. In one aspect, the present invention relates to an evaporator comprising a housing adapted to receive a bottle with a wick projecting therefrom; an electrical plug assembly, coupled to the housing, to support the evaporator in a wall outlet; a heating device disposed within the housing, in electrical communication with the electrical plug assembly, and an adjuster. The adjuster is disposed within the housing and is adapted to adjust a spacing of the wick relative to the heating device. The adjuster includes a retainer mechanism that retains the adjuster in one of a plurality of discrete adjustment positions. In another aspect, the present invention relates to an evaporator comprising a housing adapted to receive a bottle with a wick protruding from it; a heating device disposed within the housing and adapted to apply heat to the wick, and an electrical socket assembly. The electrical plug assembly includes a plug holder plate and is coupled to the housing to support the evaporator in an electrical outlet and supply power to the heating device. The plug holder plate is rotatable in order to support the evaporator in a vertical position, both in horizontal and vertical outlets. The plug support plate includes a locking mechanism which retains the plug support plate in one of a plurality of discrete positions relative to the housing. In still another aspect, the present invention relates to an evaporator comprising a housing adapted to receive a bottle with a wick projecting therefrom; a heating device disposed within the housing and adapted to apply heat to the wick; an electrical plug assembly and an adjuster. The electrical plug assembly includes a plug holder plate and is coupled to the housing for supporting the evaporator in a wall outlet and supplying power to the heating device. The plug holder plate is rotatable to support the evaporator in a vertical position in both horizontal and vertical wall outlets. The plug support plate includes a locking mechanism which retains the plug support plate in a selected position from a plurality of discrete positions relative to the housing. The adjuster is disposed within the housing and is adapted to adjust a distance of the wick relative to the heating device. The adjuster includes a retainer mechanism that retains the adjuster in a position from a plurality of discrete adjustment positions. A better understanding of these and other aspects and advantages of the invention can be had by reference to the drawings and the appended description, in which preferred embodiments of the invention are illustrated and described. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of an evaporator according to a first preferred embodiment of the present invention. Figure 2 is an exploded view of assembly of the evaporator of Figure 1. Figure 3 is a front view of the evaporator of Figure 1, set at an intermediate evaporation rate. Figure 4A is a view of the left side of the evaporator of Figure 1, with the plug holder plate fixed in a vertical socket mounting position. Fig. 4B is a view of the left side of the evaporator of Fig. 1, with the plug holder plate in a mounting position for horizontal socket. Figure 5 is a side view of the lower housing of the evaporator of Figure 1, with an enlarged detail of the serrated surface of the lower housing. Figure 6A is a high perspective view of the adjuster of Figure 1. Figure 6B is a bottom view of the evaporator adjuster of Figure 1. Figure 7 is a front elevational view of the evaporator of Figure 1, with the upper housing and the wick removed for clarity. Figure 8A is a perspective view of the front / outer surface of the plug holder plate of the evaporator of Figure 1. Figure 8B is a perspective view of the rear / internal surface of the evaporator plug support plate of Figure 1. Figure 9 is a rear view of the plug holder plate of the evaporator of Figure 1. Figure 9A is a sectional view, taken along line 9A-9A of Figure 9. Figure 9B is a sectional view taken along line 9B-9B of Figure 9. Figure 10 is a sectional view, taken following the line 10-10 of figure 3, which illustrates the coupling of the housing with the plug support plate of the evaporator of figure 1. Figure 1 1 is a perspective view of the evaporator of Figure 1, with the upper housing removed for clarity. The movement of the wick is exaggerated in this view. In all figures similar or corresponding reference numbers have been used for similar or corresponding parts. DESCRIPTION OF THE PREFERRED EMBODIMENTS An evaporator 10 according to a preferred embodiment of the invention is illustrated in Figs. As shown in Figure 1, the evaporator 10 comprises a multi-piece housing, which includes an upper housing 100 and a lower housing 200, in which a bottle 400 is detachably detached. The evaporator 10 further comprises an electrical plug assembly which includes a plug holder plate 300, rotatably secured between the upper housing 100 and the lower housing 200. The bottle 400 contains an evaporable substance (not shown) such as, for example, a liquid formulation that includes an active chemical substance, such as an insecticide, a fragrance, an odor eliminator, or the like. The term "bottle" is used herein in its widest possible sense, which includes any receptacle, container, bag, etc., capable of containing a liquid formulation. An embossed pattern 410 on one side of the bottle is coupled by an opening 1 10 in a front surface of the upper housing 100 of the evaporator 10, so as to secure the bottle 400 inside the evaporator 10. The front surface of the upper housing 100 is sufficiently flexible so that pulling the bottle 400 in a downward direction causes the embossed pattern 410 to be released from the opening 1 10 in the front surface of the upper housing 100, thereby allowing the separation of the bottle 400 from the evaporator 10 Alternatively, a neck portion of the bottle can be designed to snap into or screw into the evaporator housing. Suitable refills are available in a wide variety of liquid formulations of S.C. Johnson &; Son, Inc., of Racine, Wisconsin, under the GLADE® PLUGI NS® and RAID® brands. As best shown in Figure 2, a wick is attached 500 to the neck of the bottle 400 to bring the liquid formulation out of the bottle 400 and into an upper portion of the wick 500. A lower portion of the wick 500 is submerged in the liquid formulation, and the upper portion of the wick 500 protrudes above the neck of the bottle 400. Preferably, the wick 500 is located inside the bottle 400 by a lid 420, which includes a sheath enclosing the upper portion of the wick 500, except for an open area near the tip of the 500 wick. Alternatively a lid without a sheath can be used. Preferably the wick 500 is approximately 7 mm in diameter and is constructed of ultra high density, high density polyethylene. In the preferred embodiment illustrated in Figures 1 to 10, the multi-part housing of the evaporator comprises an upper housing 100 and a lower housing 200 which are clamped together by thermal staking or any other suitable fastening means including, for example, rivets, pressure adjustment, screws, ultrasonic welding, adhesives or similar. As best shown in Figure 2, a lower rear portion of the upper housing 100 forms an upper semicircular width 160, the ends of which define an upper interface surface 130. The lower housing 200 has a corresponding semicircular arc 260 inverted, the ends of which define a lower interface surface 230. When the upper and lower housings 100, 200 are assembled, the upper and lower semicircular arches 160, 260 combine to form a ring that retains the plug holder plate 300. The plug holder plate 300 includes a notch about its circumference. When the upper and lower housings 100, 200 are assembled, the upper and lower semicircular arches 160, 260 fit within the notch in the circumference of the plug holder plate 300, so that the support plate 300 is secured in the housing several pieces in a manner that allows the plug holder plate 300 to rotate. The collar 310 fits over the ring formed by the upper and lower arches 160, 260 and helps ensure that the upper and lower arches 160, 260 are held together tightly on the interface surfaces 130, 230. An electrical contact 320 protrudes through the plug holder plate 300 and serves the dual purpose of supplying power to the electrical components of the evaporator 10 and also to support the evaporator 10 in an electrical outlet. wall (not shown). Preferably the plug support plate 300 is rotatable (as described in more detail below) in order to support the evaporator 10 in a vertical position, both in horizontal and vertical wall outlets. The electrical contact 320 is electrically connected by means of conventional electrical conductors 330, such as wires or electrodes, to a heating device 250 for applying heat to the wick 500, when the evaporator 10 is plugged into a wall outlet. The heating device 250 is located adjacent a window 120 in the upper housing 100, so that it looks at the tip of the wick 500 when the bottle 400 is inserted in the evaporator 10. The heating of the wick 500 improves the speed at which the liquid formulation evaporates and diffuses through the window 120, and into the surrounding environment. Preferably the heating device 250 is a 6 kO metal oxide resistor, encapsulated in a ceramic block, which is capable of handling up to at least about 5 watts. The resistor preferably has characteristics of PTC (positive temperature coefficient), which means that its resistance value increases slightly as the resistor heats up. A suitable resistor is available from Great Land Enterprise Co. Ltd., of Shenzhen, China, for example. Alternatively, the heating device 250 may comprise any other suitable type of heating device, such as a resistance heater, a wire winding heater, a PTC heater, or the like. The evaporator 10 also includes an adjuster 600 which places the upper portion of the wick 500 in one of a plurality of discrete positions relative to the heating device 250. Preferably the adjuster 600 includes a hollow cylindrical portion 610 surrounding part of the upper portion of the wick 500 and engages with it. The adjuster 600 also includes a dial portion 630, accessible through an adjustment aperture 140 in the upper housing 100 (see, for example, Figure 3), to rotate the cylindrical portion 510 about an axis of rotation. The dial portion 630 is preferably integrally formed with the cylindrical portion 610, although it need not be so. Preferably, as shown in Figures 6A and 6B, a plurality of tapered ears 660 are provided on the inner surface of the cylindrical portion 610. The ears 660 are wider at their point of higher, where they remain in contact with the wick 500, and are narrower near the bottom of the cylindrical portion 610. At its uppermost point, the ears 660 define a circular opening that is barely large enough for the wick 500 to fit through it. The center of this opening is offset with respect to the axis of rotation of the cylindrical portion 610 as best shown in Figure 6B. Position indicators 640 are formed, from one to five, around the outside of the dial portion 630 to indicate to a user the current setting of the evaporation rate, with one being the lowest setting and five being the highest setting. The user can see which of the position indicators 640 is shown through the adjustment aperture 140 in the upper housing 100. A position marker 142, formed in the upper housing 100, demarcates the center of the adjustment aperture 140. In addition, a scale or intensity key 180 is located above the adjustment aperture 140 to indicate to the user in which direction the dial portion 630 rotates to increase (+) or decrease (-) the evaporation rate. For example, the evaporator 10 shown in Figure 3 is in an intermediate evaporation rate setting, as evidenced by the number 3 position indicator 640 which is aligned with the position marker 142. To increase the vaporization rate, the The user only has to rotate the dial portion 630 to the symbol (+) of the key 180 (ie, to the right in Figure 3). Conversely, to decrease the evaporation rate the user simply rotates the dial portion towards the symbol (-) (ie, to the left in Figure 3). While 640 indicators are illustrated as Arabic numerals, other suitable indicators could also be used, such as Roman numerals, symbols, colors, images, or the like. In addition, while five indicators are illustrated, any desired number of indicators could be used. Figure 1 1 illustrates the evaporator 10 in the same intermediate evaporation setting as in figure 3. The rotation of the dial portion 630 of the adjuster 600 causes the wick 500 to move in close proximity to the heating device 250 (the direction (+ ) in Fig. 1 1) or away from the heating device 250 (the direction (-) in Fig. 1 1), in a lateral direction, ie in a direction substantially perpendicular to the longitudinal axis of the wick 500. The position of the wick 500 in the positions of minimum (-) and maximum (+) evaporation intensity is shown in dotted form in figure 1 1. These minimum and maximum positions are exaggerated in Figure 11 for clarity. In the minimum intensity setting, the axis of the wick 500 is located approximately 6.3 mm from the heating device 250. In this position the wick is heated to a temperature of approximately 71 to 78 ° C. The rotation of the dial portion 630 approximately 180 degrees to the right brings the wick shaft to a position that is approximately 4.4 mm from the heating device 250. At this maximum setting the wick is heated to a temperature of about 85-70 ° C. 90 ° C, which results in a higher evaporation rate. The lateral distance at which the wick 500 moves when moving it from the minimum intensity position to the maximum intensity position preferably is between about 1 mm and about 3.5 mm. In the preferred particular mode described above, the lateral distance at which the wick 500 travels is about 2 mm. Weight loss tests have shown that the evaporation rate is almost 100 percent higher at the maximum position than at the minimum position.

The angle through which the dial portion 630 can be rotated to move the wick 500 throughout its range of motion is not crucial, and can be easily varied, for example, by adjusting the degree of eccentricity of the tapered ears 660. it can set the evaporator 10 to any of a plurality of intermediate discrete positions between the minimum and maximum positions. The adjuster includes a retainer mechanism that retains the adjuster 600 in one of a plurality of discrete adjustment positions. As shown in Figure 7, the retainer mechanism of the adjuster 600 preferably comprises a rigid retainer catch 650 connected to the dial portion 630 by a flexible cantilever arm 655. The retainer catch 650 depends on the cantilever arm 655 and is forcibly carried by the cantilever arm 655 until contact with a serrated surface 210 of the lower housing 200. A retainer lip 620 of the adjuster 600 engages a flange 220 of the lower housing to hold the adjuster 600 and, consequently, the retainer latch 650, in contact with the surface of serrated form 210.

The serrated surface 210 of the lower housing comprises a plurality of peaks 210 and valleys 212, arranged in a substantially circular configuration, as best illustrated in the enlarged detail of the view of Figure 5. Each of the valleys 212 corresponds to one of the plurality of discrete positions. In this way, when a user rotates the dial portion 630 of the adjuster 600, the retainer latch 650 travels along the surface 210 in a serrated manner and provides a sound and ratchet sensation, whereby the user can perceiving (both by auditory perception and by tactile perception) the movement of adjuster 600 from one discrete position to the next, as retainer latch 650 moves up and over each successive peak 210 and downward, to the next valley 212 successive. The ratchet action of the adjuster 600 allows the user to quickly adjust the evaporation rate of the evaporator 10 by a predetermined amount, for example, four valleys. Consequently, the repeatability of the adjustment is also simplified, since the adjuster 600 can simply be adjusted in a known number of valleys, instead of trying to match the indicator with a previous position. Preferably a cut-out section 670 of the adjuster 600 limits the range of movement of the adjuster to approximately 75 degrees. However, alternatively, the adjuster 600 could be made to rotate through any other desired angle, including that it could rotate continuously. As mentioned above, the electric plug assembly, which includes the plug holder plate 300, can preferably be rotated so as to support the evaporator 10 in a vertical position in both horizontal and vertical wall outlets. The plug support plate 300 is provided with a locking mechanism that locks the plug support plate 300 in a desired position from a plurality of use positions. As illustrated in Figures 8 to 10, the locking mechanism preferably comprises a stationary projection 1 50, formed in the upper housing 1 00, and a pair of left and right locking projections 340, 342, formed in different positions of the plug holder plate 300. The plug holder plate 300 preferably also includes a pair of left and right stop faces 350, 352, to limit the rotation of the plug holder plate 300, to a desired scale of angles. In the preferred embodiment shown in Figures 8 to 10, the plug holder plate 300 is rotatable through only 90 degrees; however, it may be convenient, in some cases, to make the en support plate swivel through any desired angle, such as 1 80 degrees, 360 degrees, or even that it can rotate continuously. While the preferred construction of the locking mechanism is described, those skilled in the art will understand that the locking mechanism can be constructed by any combination of projections and indentations, formed in the housing 100, 200, or in the support plate of the enclosure 300. , which allows the plug support plate 300 to be locked in a plurality of different positions. Thus, another suitable configuration of the locking mechanism includes at least one of a projection and an indentation, formed in the housing, which engages at least one other between a projection and an indentation, formed in the plug support plate. . The plug holder plate 300 is shown in Figures 4, 10 and 11, in a position for use in a vertical wall receptacle, with the plug holder plate 300 rotated in a maximum left-handed direction. In that position, the stop face 350 abuts a portion of the upper housing 100 to prevent further rotation in the left-hand direction, while the left working projection 340 is locked in place by the stationary projection 150. When the user wishes to plug in the In a horizontal outlet, the user simply rotates the plug support plate 300 in a clockwise direction to the orientation shown in FIG. 4B. When the user begins to rotate the plug holder plate 300 in the clockwise direction, the left locking projection 340 rises against the stationary projection 150, which causes the plug holder plate 300 to move slightly away from the upper housing 100, in the axial direction (downwards in FIG. 10), as allowed by a slight deformation of the plug support plate 300 and the upper housing 100. This light separation allows the left locking projection 340 to slide on the stationary projection 150. The support plate The plug 300 will continue to rotate in the clockwise direction until the right hand projection 342 rises against the stationary projection 150, which causes the plug holder plate 300 to deform again and slightly separate from the upper housing 100. This light spacing allows the right hand projection 340 slides on the stationary projection 150, until the rota maximum dextrorotatory ion.

In that position the right stop face 352 abuts a portion of the upper housing 100, to prevent further rotation in a clockwise direction, while the right locking projection 340 is locked in place by the stationary projection 150. Thus, the 300 plug holder plate is securely locked in each of the appropriate usage positions. Preferably, each time one of the left or right locking projections 340, 342 is pushed past the stationary projection 150, an audible "click" sound is produced, so that the user knows that the plug support plate 300 has reached its position of appropriate use. The evaporator may be provided with several other aspects, such as one or more of: a fan to increase the diffusion of the active substance in a room; louvers formed in the housing to further increase the diffusion of the active substance; one or more additional receptacles to plug an additional electrical device through the evaporator, and appropriate circuits, necessary to provide these aspects. Each of these aspects can be provided in a known manner, as described, for example, in the publication '241, which has been incorporated herein by reference. The modalities discussed in the foregoing are representative of preferred embodiments of the invention, and are provided solely for illustrative purposes. They are not intended to limit the scope of the invention. Although structures, dimensions, components, etc. have been shown , specific, and have been described, are not limitations. Modifications and variations are contemplated within the scope of the present invention, which is intended to be limited only by the scope of the claims that follow. Industrial Applicability The present invention provides an electric evaporator for use with liquid formulations containing a chemical active substance, such as an insecticide, a fragrance, or the like. The evaporator includes an improved toothed adjuster for varying the evaporation rate of the liquid formulation. In this way, the concentration of the active chemical towards the surrounding environment can be precisely controlled, depending on the preferences of the user.

Claims (13)

1. REIVI NDICATIONS
2. 1 . An evaporator comprising: a housing, adapted to receive a bottle with a wick projecting therefrom; an electrical plug assembly, coupled to the housing, to support the evaporator in a wall outlet; a heating device disposed within the housing, in electrical communication with the electrical plug assembly; and an adjuster disposed in the housing and adapted to adjust a separation of the wick relative to the heating device; the adjuster including a retainer mechanism that retains the adjuster in one of a plurality of discrete adjustment positions. An evaporator according to claim 1, further comprising a bottle containing a substance to be evaporated and a wick having a lower portion disposed in the substance of the bottle and an upper portion protruding from the bottle.
3. 3. An evaporator according to claim 2, wherein the bottle and the wick are received detachably by the housing.
4. An evaporator according to claim 1, the retainer mechanism comprising a retainer latch that is forcibly carried downward and displaced against the housing to retain the adjuster in a desired position from the plurality of discrete adjustment positions.
5. 5. An evaporator according to claim 4, further comprising the retainer mechanism a cantilever arm forcibly carrying the retainer catch downward, to move against the housing.
6. 6. An evaporator according to claim 5, the housing including a serrated shaped trim surface against which the retainer latch is forcibly carried; the serrated trim surface having a plurality of peaks and valleys; each valley defining a position among the plurality of discrete positions of the adjuster.
7. 7. An evaporator according to claim 6, the retainer latch being rigid and the cantilever arm being flexible to allow the retainer latch to move upward on each of the plurality of peaks and downwardly, within each of the peaks. plurality of valleys as it travels along the serrated fit surface of the housing.
8. An evaporator according to claim 6, wherein the rotation of the adjuster causes a movement and a rattle when the retainer latch travels along the serrated surface of the housing; so that the user can perceive the movement of the adjuster between each of the plurality of discrete positions, by auditory and tactile perception.
9. 9. An evaporator according to claim 4, the adjuster further comprising a hollow cylindrical portion adapted to receive the upper portion of the wick.
10. An evaporator according to claim 9, the adjuster further comprising a dial portion for rotating the hollow cylindrical portion about an axis of rotation. 1.
11. An evaporator according to claim 10, wherein the dial portion is integrally formed with the hollow cylindrical portion.
12. 12. An evaporator according to claim 9, wherein the hollow cylindrical portion is rotatable through a rotation range of about 180 degrees.
13. 13. An evaporator according to claim 9, wherein the hollow cylindrical portion defines an opening through which the wick extends, and the center of the opening is offset with respect to the axis of rotation of the hollow cylindrical portion. . An evaporator according to claim 1, the adjuster further comprising a hollow cylindrical portion adapted to receive the upper portion of the wick, and a dial portion formed integral with the hollow cylindrical portion for rotating the hollow cylindrical portion about an axis of rotation; and the retainer mechanism comprises a retainer catch that is forcibly brought into contact with a serrated fit surface of the housing, for retaining the adjuster in the desired position from among the plurality of adjustment positions; the serrated-shaped adjustment surface has a plurality of peaks and valleys, each valley defining a position of the plurality of discrete positions of the adjuster. An evaporator comprising: a housing adapted to receive a bottle with a wick protruding therefrom; a heating device disposed within the housing and adapted to apply heat to the wick; and an electrical plug assembly including a plug holder plate, coupled to the housing for supporting the evaporator in a wall outlet, and for supplying power to the heating device; the plug support plate being rotatable in order to support the evaporator in a vertical position in horizontal and vertical wall outlets; the plug support plate including a locking mechanism which retains the plug support plate in a position of a plurality of discrete positions with respect to the housing; and an adjuster, disposed within the housing and adapted to adjust a gap between the wick and the heating device; the adjuster including a retainer mechanism that retains the adjuster in a position from a plurality of discrete adjustment positions. An evaporator according to claim 15, the adjuster further comprising a hollow cylindrical portion, adapted to receive the upper portion of the wick, and a dial portion formed integral with the hollow cylindrical portion, to rotate the hollow cylindrical portion around an axis of rotation; and the retainer mechanism comprises a fastener that is forcibly brought into contact with a serrated fit surface of the housing, for retaining the adjuster in the desired position from among the plurality of adjustment positions; the sawn-shape adjustment surface has a plurality of peaks and valleys, each valley defining a position from among the plurality of discrete positions of the adjuster. An evaporator according to claim 16, the locking mechanism comprising at least one projection formed in the housing, which engages at least one projection formed in the plug holder plate, to lock the plug holder plate in a position among the plurality of discrete positions; and the plug support plate additionally comprising a left stop face for limiting the rotation of the plug holder plate in a left-handed direction, and a right stop face for limiting the rotation of the plug holder plate in a clockwise direction.