DISHWASHER APPLIANCE WITH LOW VOLTAGE ELECTRICAL COMPONENTS

Information

  • Patent Application
  • 20140000665
  • Publication Number
    20140000665
  • Date Filed
    June 29, 2012
    12 years ago
  • Date Published
    January 02, 2014
    10 years ago
Abstract
A dishwasher appliance is provided. The dishwasher appliance includes a door for providing access to a wash chamber of the dishwasher appliance. A low voltage electrical component is mounted within the door and is in electrical communication with a low voltage power source. By utilizing the low voltage power source and the low voltage electrical component, the reliability of the dishwasher appliance can be improved.
Description
FIELD OF THE INVENTION

The present subject matter relates generally to dishwasher appliances and, in particular, to dishwasher appliances with electrical components within a door of the appliance.


BACKGROUND OF THE INVENTION

Dishwasher appliances are generally connected to a household electrical system that provides high voltage electrical power to operate the dishwasher appliance. In particular, the dishwasher appliance is generally wired to receive one hundred and twenty volt, alternating current (AC) electrical power from the household electrical system. The dishwasher appliance utilizes such high voltage electrical power to operate the various components of the appliance. For example, in certain dishwasher appliances, such high voltage electrical power is utilized to operate a circulation pump, a drain pump, a heating element, and/or a control board of the appliance.


In addition, such high voltage electrical power is also used to power dishwasher components located within a door of the dishwasher appliance. For example, in certain dishwasher appliances, such high voltage electrical power is utilized to operate a user control panel, a detergent dispenser motor, and/or a fan located within or attached to the appliance's door. However, an interior of the dishwasher door can be a corrosive environment due to many factors, for example, high humidity, high temperatures, and the presence of detergent and rinse aid.


Utilizing high voltage electrical power to operate dishwasher components located within the door's corrosive environment can decrease the reliability of the dishwasher appliance. In particular, a large number of dishwasher appliances have failed due to corrosion of high voltage electrical components located with the dishwashers' doors. Such failures have also led to expensive recalls of the dishwasher appliances.


Accordingly, a dishwasher appliance with features for improving reliability of the dishwasher appliance would be useful. In particular, a dishwasher appliance with features for improving reliability of electrical components within the dishwasher appliance's door would be useful. Further, a dishwasher appliance without high voltage electrical components located within a door of the appliance would be useful.


BRIEF DESCRIPTION OF THE INVENTION

The present subject matter provides a dishwasher appliance with a door for providing access to a wash chamber of the dishwasher appliance. A low voltage electrical component is mounted within the door and is in electrical communication with a low voltage power source. By utilizing the low voltage power source and the low voltage electrical component, the reliability of the dishwasher appliance can be improved. Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.


In a first exemplary embodiment, a dishwasher appliance is provided. The dishwasher appliance includes a tub that defines a wash chamber. A door is mounted proximate to the tub and is configured for permitting selective access to the wash chamber of the tub. The door contains no high voltage electrical components. A low voltage power source is also provided. A low voltage electrical component is positioned proximate the door and is in electrical communication with the low voltage power source.


In a second exemplary embodiment, a dishwasher appliance is provided. The dishwasher appliance includes a tub that defines a wash chamber. A door is mounted proximate the tub. The door is configured for permitting selective access to the wash chamber of the tub. The door contains no high voltage electrical components. A control board is also provided. The control board is configured to be powered by a high voltage power supply. The control board has a low voltage power source for transforming high voltage power from the high voltage power supply to low voltage power. A low voltage electrical component is positioned proximate the door and is in electrical communication with the low voltage power source of the control board. A high voltage electrical component is mounted adjacent the tub and is in electrical communication with said control board.


These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.





BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:



FIG. 1 provides a front view of a dishwasher appliance according to an exemplary embodiment of the present subject matter.



FIG. 2 provides a side, cross-sectional view of the dishwasher appliance of FIG. 1.



FIG. 3 illustrates an exploded view of an exemplary embodiment of a door of the dishwasher appliance of FIG. 1.



FIG. 4 is a schematic view of the dishwasher appliance of FIG. 1 that illustrates various operational components of the dishwasher appliance.





DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.



FIGS. 1 and 2 depict an exemplary dishwasher appliance 100 according to an exemplary embodiment of the present subject matter. As best shown in FIG. 2, dishwasher appliance 100 includes a cabinet 102 with a tub 104 mounted therein that defines a wash chamber 106. Tub 104 includes a front opening (not shown) and a door assembly 200 hinged at its bottom 122 for movement between a normally closed, vertical position (shown in FIGS. 1 and 2), wherein wash chamber 106 is sealed shut for washing operation, and a horizontal, open position for loading and unloading of articles from dishwasher appliance 100.


Rack assemblies 130 and 132 are slidably mounted within wash chamber 106. Rack assemblies 130 and 132 are configured for receipt of articles for washing, e.g., plates, cups, bowls, or any suitable combination thereof. Each of the rack assemblies 130, 132 is fabricated into lattice structures including a plurality of elongated members 134. Each rack 130, 132 is adapted for movement between an extended loading position (not shown) in which rack is substantially positioned outside wash chamber 106 for facilitating loading of articles therein, and a retracted position (shown in FIGS. 1 and 2) in which the rack is located inside wash chamber 106, e.g., during operation of dishwasher appliance 100.


Dishwasher appliance 100 further includes a lower spray assembly 144 that is (e.g., rotatably) mounted within a lower region 146 of wash chamber 106 and above a sump portion 142 of tub 104 so as to be positioned in relatively close proximity to rack assembly 132. A mid-level spray assembly 148 is located in an upper region of wash chamber 106 and is located in close proximity to upper rack 130. Additionally, an upper spray assembly 150 is located above upper rack 130.


Lower and mid-level spray assemblies 144 and 148 and upper spray assembly 150 are fed by a fluid circulation assembly 152 for circulating water and washing liquid (e.g., a solution of detergent, water, and/or rinse aid) within wash chamber 106 of tub 104. Fluid circulation assembly 152 includes a recirculation pump 161 positioned within a machinery compartment 140 located below sump portion 142 of tub 104. Lower and mid-level spray assembly 144 and 148 includes an arrangement of discharge ports or orifices for directing washing liquid onto dishes or other articles located in upper and lower rack assemblies 130 and 132. The arrangement of the discharge ports in lower and mid-level spray assemblies 144 and 148 provides a rotational force by virtue of washing liquid flowing through the discharge ports. The resultant rotation of lower and mid-level spray assemblies 144 and 148 can provide coverage of dishes and other dishwasher contents with a spray of washing liquid.


Dishwasher appliance 100 is equipped with a heating element 160. Heating element 160 is configured for heating wash liquid and/or water within dishwasher appliance 100. As an example, heating element 160 can function as a booster water heater to increase the temperature of wash liquid within the wash chamber 106, e.g., to a suitable or appropriate temperature for the desired cycle of dishwasher appliance 100. Further, heating element 160 may function to assist drying of articles in upper and lower rack assemblies 130 and 132 during a drying cycle of dishwasher appliance 100. In particular, heating element 160 may be activated to raise the ambient temperature within wash chamber 106 thereby facilitating or expediting drying of articles in upper and lower rack assemblies 130 and 132.


In the exemplary embodiment shown in FIG. 2, heating element 160 is mounted within wash chamber 106, proximate sump portion 142 of tub 104. However, in alternative exemplary embodiments, heating element 160 may be mounted at any suitable location. For example, heating element 160 may be mounted within machinery compartment 140 or within sump portion 142 of tub 104. Heating element 160 may be an electrical resistance heating element or any other suitable mechanism for increasing the temperature of liquid and/or the ambient atmosphere within the wash chamber 106. Also, in alternative exemplary embodiments, heating element 160 may be constructed as two distinct components: (1) a component for heating liquid entering or within wash chamber 106; and (2) another component for assisting with drying articles in upper and lower rack assemblies 130 and 132.


Dishwasher appliance 100 is further equipped with a control board or controller 165 to regulate operation of dishwasher appliance 100. The controller 165 may include a memory and microprocessor, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor.


Controller 165 may be positioned in a variety of locations throughout dishwasher appliance 100. In the illustrated embodiment, controller 165 is located within machinery compartment 140 below tub 104. In particular, controller 165 is mounted within a container or case 180 mounted to tub 104 within machinery compartment 140. Case 180 protects and isolates controller 165 within machinery compartment 140. For example, case 180 is constructed of a metal or other non-flammable material in order to provide for safer operation of dishwasher appliance 100. In particular, by enclosing controller 165 inside a metal case, any failure of the controller 165 will be contained within the case, and potential damage to the dishwasher appliance 100 due to such failure can be mitigated. However, in alternative exemplary embodiments, case 180 may be mounted at any other suitable location within dishwasher appliance 100, e.g., to cabinet 102.


In the embodiment shown in FIG. 2, input/output (“I/O”) signals may be routed between controller 165 and various operational components of dishwasher appliance 100 along wiring harnesses as discussed in greater detail below. As an example, controller 165 is in electrical communication with a user input panel 216 (FIG. 1) that includes a plurality of user inputs 136. The plurality of user inputs 136 permits a user to select various operational features and modes and monitor progress of dishwasher appliance 100. In an exemplary embodiment, plurality of user inputs 136 can include a general purpose I/O (“GPIO”) device or functional block. In another exemplary embodiment, plurality of user inputs 136 can include one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. User input panel 216 may also include a display component, such as a digital or analog display device designed to provide operational feedback to a user. User input panel 216 may be in communication with controller 165 via one or more signal lines or shared communication busses.


User input panel 216 shown herein is generally referred to a “front-control” control panel. However, as will be understood by those skilled in the art, dishwasher appliance 100 may be provided with other suitable control panels, e.g., “top-control” control panels. Similarly, it should be appreciated that the present subject matter is not limited to any particular style, model, or configuration of dishwasher, and that the embodiment depicted in FIGS. 1 and 2 is for illustrative purposes only. For example, instead of racks 130, 132 depicted in FIG. 1, dishwasher appliance 100 may be of a known configuration that utilizes drawers that pull out from cabinet 102 and are accessible from the top for loading and unloading of articles. Also, dishwasher appliance 100 may not include an external cabinet and may, instead, include a wash chamber or tub mounted to a chassis that is not provided with external cabinetry other than door assembly 200. Other configurations may be used as well.



FIG. 3 illustrates an exploded view of door assembly 200 of dishwasher appliance 100 (FIG. 1). Door assembly 200 includes an inner door panel 210 and an outer door panel 220. As will be understood by those skilled in the art, inner and outer door panels 210 and 220 are selectively coupled or secured together in order to form door assembly 200.


Inner door panel 210 includes a detergent and/or rinse aid dispenser 275 mounted to inner door panel 210 with a bracket 276. A user can fill detergent and/or rinse aid dispenser 275 with detergent prior to starting dishwasher appliance 100 (FIG. 1), and detergent and/or rinse aid dispenser 275 may dispense such detergent and/or rinse aid during operation of dishwasher appliance 100 Inner door panel 210 also includes a vent 277 that is in fluid communication with wash chamber 106 of tub 104 (FIG. 2) when door assembly 200 is in the closed position. Water vapor and/or steam can be directed out of wash chamber 106 through vent 277, e.g., during a drying cycle of dishwasher appliance 100. In particular, a fan 278 is mounted to inner door panel 210 and is configured for selectively urging a flow of fluid (e.g., air, steam, and/or water vapor) out of wash chamber 106 though vent 277. User input panel 216 is also mounted to inner door panel 210. Outer door panel 220 defines a handle recess 254 that permits access to a handle (not shown) mounted beneath user input panel 216 for assisting in opening and closing door assembly 200.


As discussed in greater detail below, door assembly 200 contains only low voltage electrical components 172 (FIG. 4). Thus, door assembly 200 contains no high voltage electrical components 170 (FIG. 4). As used herein, the term “low voltage” means a maximum, nominal voltage of about forty-two volts between conductors and between conductors and earth or, for three phase circuits, a maximum, nominal voltage of about twenty-four volts between conductors and neutral. Conversely, as used herein, the term “high voltage” means a nominal voltage greater than about forty-two volts between conductors and between conductors and earth or, for three phase circuits, a nominal voltage greater than about twenty-four volts between conductors and neutral.



FIG. 4 is a schematic view of dishwasher appliance 100 that illustrates various operational components of the dishwasher appliance 100. As may be seen in FIG. 4, controller 165 is in electrical communication with a high voltage power supply 164 that provides electrical power to operate controller 165 and various other operation components of dishwasher appliance 100 as described in greater detail below. High voltage power supply 164 has a nominal output voltage of greater than about forty-two volts between conductors and between conductors and earth.


As will be understood by those skilled in the art, high voltage power supply 164 may be a residential or commercial electrical system for a building (not shown) housing dishwasher appliance 100. In particular, high voltage power supply 164 may include an individual circuit of a breaker panel box (not shown). As an example, such individual circuit can deliver one hundred and twenty volt nominal AC power to controller 165. However, in alternative exemplary embodiments, such individual circuit can deliver two hundred and forty volt nominal AC power or any other suitable voltage of AC or DC electrical power.


Controller 165 is in electrical communication with a plurality of low voltage electrical components 172 and a plurality of high voltage electrical components 170. Controller 165 is in electrical communication with high voltage and low voltage electrical components 170 and 172 in order to provide electrical power and enable operation of the high voltage and low voltage electrical components 170 and 172. In particular, a high voltage harness 171 electrically connects the high voltage components 170 to controller 165. Similarly, a low voltage harness 173 (also shown in FIG. 3) electrically connects the low voltage electrical components 172 to controller 165. As will be understood by those skilled in the art, high voltage and low voltage harnesses 171 and 173 may include wires, cables, and/or other electrical conduits that extend between and electrically connect the controller 165 and the high voltage and low voltage electrical components 170 and 172, respectively.


In the particular embodiment shown in FIG. 4, high voltage electrical components 170 and low voltage electrical components 172 are positioned in disparate portions of dishwasher appliance. In particular, the low voltage electrical components 172 are positioned on or within door assembly 200 (FIG. 1) of dishwasher assembly 100. Conversely, the high voltage electrical components 170 are positioned on or within components of dishwasher appliance 100 other than door assembly 200, e.g., within wash chamber 106 or machinery compartment 140 or on tub 104 (FIG. 2). In alternative exemplary embodiments, the low voltage electrical components 172 may be located anywhere within dishwasher appliance 100, e.g., on tub 104. However, no high voltage electrical components 170 are located within door assembly 200 (FIG. 1), e.g., in order to increase the reliability of dishwasher appliance 100 as described in greater detail below.


Controller 165 is configured for selectively operating high voltage and low voltage electrical components 170 and 172. For example, controller 165 may selectively activate heating element 160 to heat liquid or dry articles within wash chamber 106 (FIG. 2) as described above. Similarly, controller 165 may selectively activate recirculation pump 161 to direct a flow of fluid to spray assemblies 144, 146, and 150 (FIG. 2), or controller 165 may activate a drain pump 162 that is configured for directing liquid within sump portion 142 of tub 104 (FIG. 2) to a drain (not shown) where such liquid can exit dishwasher appliance 100. As may be seen in FIG. 4, the components of dishwasher appliance 100 described above are high voltage electrical components 170. Thus, such components operate on high voltage power, e.g., one hundred and twenty volt AC power delivered to controller 165 from high voltage power supply 164.


Controller 165 also includes a low voltage power source 166. Low voltage power source 166 is configured for transforming high voltage electrical power (e.g., about one hundred and twenty volt AC electrical power) to low voltage electrical power (e.g., about twenty-four volt DC electrical power). In particular, low voltage power source 166 may be configured to transform high voltage electrical power received from high voltage power supply 164 to low voltage electrical power in order to provide such low voltage electrical power to low voltage electrical components 172. Low voltage power source 166 is also designed to provide isolation from high voltage power supply 164 and meet applicable regulatory standards, e.g. UL or NEC. Low voltage power source 166 may have a maximum, nominal output voltage of between about forty-two volts and about zero volts between conductors and between conductors and earth, e.g., about twenty-four volts AC or DC between conductors and between conductors and earth.


As an example, low voltage power source 166 may be a Class II power source. As used herein, the term “Class II” power source means a power source configured in accordance with UL Standard 60730-1, Section 2.7.5. Thus, low voltage power source 166 may include protective features such as double insulation and/or reinforced insulation of conducting components of low voltage power source 166. Also, low voltage power source 166 need not be grounded to earth. In a configuration with low voltage power source 166 configured as a Class II power source, low voltage harness 173 comprises a Class II circuit with the corresponding safety features that will be well understood by those skilled in the art, e.g., electrical shock safety.


The maximum volt-ampere output of low voltage power source 166 may also be limited to one hundred volt-amperes, e.g., to increase reliability of dishwasher appliance 100. Similarly, the output power capability of the low voltage power source 166 may be hardware (HW) limited, e.g., using a fuse or breaker, to prevent any of the low voltage electrical components 172 from exceeding a particular power output, e.g, of about fifteen watts of power. Conversely, low voltage power source 166 may include multiple branches that each powers a respective one of the low voltage electrical components 172. Each branch of low voltage power source 166 may be HW limited to prevent any of the low voltage electrical components 172 from exceeding a particular power output, e.g, of about fifteen watts of power.


In addition, it should be understood that dishwasher appliance 100 may include multiple low voltage power sources 166 configured to transform high voltage electrical power received from high voltage power supply 164 to low voltage electrical power in order to provide low voltage electrical power to low voltage electrical components 172. For example, each one of the multiple low voltage sources 166 may power a respective one of the low voltage electrical components 172. Each one of the multiple low voltage sources 166 may also be limited to fifteen watts of power.


Low voltage power source 166 is in electrical communication with low voltage electrical components 172 via low voltage harness 173. In particular, low voltage power source 166 provides low voltage electrical power to operate low voltage electrical components 172. As discussed above, low voltage electrical components 172 are located within or on door assembly 200. By providing low voltage electrical power to low voltage electrical components 172 rather than high voltage electrical power from high voltage power supply 164, the reliability or robustness of dishwasher appliance 100 can be improved.


In particular, door assembly 200 can contain a relatively corrosive environment compared to other sections dishwasher appliance 100, e.g., due to high humidity, high temperatures, and the presence of detergent and/or rinse aid. By operating only low voltage electrical components 172 within door assembly 200, the reliability of dishwasher appliance 100 can be improved. Further, by hardware limiting the output power capability of the low voltage power source 166, the risk of excessive power on any of the low voltage electrical component 172 can be further mitigated, and the reliability of the dishwasher appliance 100 can be similarly improved.


In alternative exemplary embodiments, dishwasher appliance 100 need not include any high voltage electrical components 170 such that dishwasher appliance 100 operates with only low voltage electrical components 172, e.g., to further improve reliability of dishwasher appliance 100. For example, in such embodiments, heating element 160 and/or recirculation pump 161 may be low voltage electrical components 172 such that they operate on low voltage electrical power.


In further alternative exemplary embodiments, low voltage electrical components 172 may include additional components of dishwasher appliance 100 not shown in FIG. 4. For example, low voltage electrical components 172 may include an ozone generation device or a sanitization dispenser. Such components may be mounted within door assembly 200 or at any other suitable location within dishwasher appliance 100.


In additional alternative exemplary embodiments, door assembly 200 may include at least one switch (not shown). The at least one switch is electrically connected to low voltage power source 166, e.g., with low voltage harness 173. Further, the at least one switch is electrically connected to a hardware interlock (not shown), e.g., on controller 165. Such hardware interlock removes or disconnects power, e.g., to any of the high voltage and/or low voltage electrical components 170 and 172 when door assembly 200 is the open position.


This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims
  • 1. A dishwasher appliance comprising: a tub defining a wash chamber;a door mounted proximate to said tub and configured for permitting selective access to the wash chamber of said tub, said door containing no high voltage electrical components;a low voltage power source; anda low voltage electrical component positioned within or on said door and in electrical communication with said low voltage power source.
  • 2. The dishwasher appliance of claim 1, further comprising a harness extending between said low voltage power source and said low voltage electrical component, said harness placing said low voltage electrical component and said low voltage power source in electrical communication.
  • 3. The dishwasher appliance of claim 1, wherein said low voltage power source comprises a Class II power source.
  • 4. The dishwasher appliance of claim 1, wherein said low voltage power source has a maximum power output of about fifteen watts.
  • 5. The dishwasher appliance of claim 1, wherein said low voltage power source has a maximum, nominal output voltage between about zero volts and about forty-two volts.
  • 6. The dishwasher appliance of claim 1, wherein said low voltage power source is disposed within a machinery chamber defined below said tub.
  • 7. The dishwasher appliance of claim 1, wherein said low voltage electrical component comprises at least one of: a user input panel mounted at a top portion of said door;a fan mounted within said door; anda detergent and/or rinse aid dispenser mounted to said door.
  • 8. The dishwasher appliance of claim 1, further comprising: a control board in electrical communication with said low voltage power source;a high voltage power supply in electrical communication with said control board; anda high voltage electrical component disposed adjacent said tub and in electrical communication with said control board.
  • 9. The dishwasher appliance of claim 7, wherein said control board is disposed within a machinery chamber defined below said tub.
  • 10. The dishwasher appliance of claim 8, wherein said control board is disposed within a container mounted to said tub.
  • 11. The dishwasher appliance of claim 7, wherein said high voltage electrical component comprises at least one of: a heating element disposed within the wash chamber of said tub; anda pump in fluid communication with the wash chamber of said tub.
  • 12. A dishwasher appliance comprising: a tub defining a wash chamber;a door mounted to said tub and configured for permitting selective access to the wash chamber of said tub, said door containing no high voltage electrical components;a control board configured to be powered by a high voltage power supply, said control board having a low voltage power source for transforming high voltage power from said high voltage power supply to low voltage power;a low voltage electrical component mounted within or on said door and in electrical communication with the low voltage power source of said control board; anda high voltage electrical component mounted to said tub and in electrical communication with said control board.
  • 13. The dishwasher appliance of claim 12, further comprising a harness extending between the low voltage power source of said control board and said low voltage electrical component, said harness placing said low voltage electrical component and the low voltage power source of said control board in electrical communication.
  • 14. The dishwasher appliance of claim 12, wherein the low voltage power source of said control board comprises a Class II power source.
  • 15. The dishwasher appliance of claim 12, wherein said low voltage power source has a maximum, nominal output voltage between about zero volts and about forty-two volts.
  • 16. The dishwasher appliance of claim 12, wherein said low voltage power source has a maximum power output of about fifteen watts.
  • 17. The dishwasher appliance of claim 12, wherein said low voltage electrical component comprises at least one of: a user input panel mounted to a top of said door;a fan mounted within said door; anda detergent and/or rinse aid dispenser mounted to said door.
  • 18. The dishwasher appliance of claim 12, wherein said control board is disposed within a machinery chamber defined below said tub.
  • 19. The dishwasher appliance of claim 17, wherein said control board is disposed within a container mounted to said tub.
  • 20. The dishwasher appliance of claim 12, wherein said high voltage electrical component comprises at least one of: a heating element disposed within the wash chamber of said tub; anda pump in fluid communication with the wash chamber of said tub.