FOOD WASTE DISPOSER NOISE REDUCTION USING ACTIVE NOISE CONTROL

Abstract

A food waste disposer system (300) has active noise control of food waste disposer noise that is generated by the food waste disposer (302) when a motor of the food waste disposer (302) is running. The food waste disposer (302) has a food conveying section that conveys food waste to a grinding section. The grinding section has a rotatable shredder plate that is rotated by a motor of a motor section. Active noise sound waves (310) are radiated into an area (313) where the food waste disposer noise is to be controlled at an amplitude and frequency to at least cancel or mask the food waste disposer noise.

Claims

1. A method of controlling food waste disposer noise that is generated by a food waste disposer when a motor of the food waste disposer is running, comprising: radiating active noise sound waves into an area where the food waste disposer noise is to be controlled at an amplitude and frequency to at least cancel or mask the food waste disposer noise.

2. The method of claim 1 wherein radiating the active noise sound waves includes radiating them at an amplitude and a frequency to both cancel and mask the food waste disposer noise.

3. The method of claim 1 wherein radiating the active noise sound waves includes radiating them into an interior of a food conveying section of the food waste disposer.

4. The method of claim 3 wherein radiating the active noise sound waves includes radiating them with an active noise source having a portion that extends through a wall of a housing of the food conveying section.

5. The method of claim 3 wherein radiating the active noise sound waves includes radiating them with an active noise source disposed in a stopper received in a sink drain outlet of a sink to which the food waste disposer is mounted.

6. The method of claim 1 wherein radiating the active noise sound waves includes radiating them into an interior of a tubular body of a sink flange to which the food waste disposer is mounted.

7. The method of claim 6 wherein radiating the active noise sound waves includes radiating them with an active noise source having a portion that extends through a wall of the tubular body of the sink flange.

8. The method of claim 1 wherein the area is above an inlet at an upper end of the food waste disposer and radiating the active noise sound waves includes radiating them to the area above the inlet at the upper end of the food waste disposer with an active noise source disposed in a stopper received in a sink drain outlet of a sink to which the food waste disposer is mounted.

9. The method of claim 1 wherein radiating the active noise sound waves includes radiating them in an interior of a cabinet in which the food waste disposer is disposed.

10. The method of claim 9 wherein radiating the active noise sound waves includes radiating them with an active noise source disposed in the cabinet.

11. The method of claim 1 including generating the active noise sound waves by vibrating a wall of a sink to which the food waste disposer is mounted.

12. The method of claim 1 including generating the active noise sound waves by vibrating a wall of a cabinet in which the food waste disposer is disposed.

13. The method of claim 1 including generating the active noise sound waves by vibrating a wall of a conveying housing of a food conveying section of the food waste disposer or vibrating a wall of a tubular body portion of a sink flange to which the food waste disposer is mounted.

14. A food waste disposer system with active noise control of food waste disposer noise that is generated by the food waste disposer when a motor of the food waste disposer is running, comprising: a food waste disposer having a food conveying section that conveys food waste to a grinding section, the grinding section having a rotatable shredder plate that is rotated by a motor of a motor section; and an active noise source that radiates active noise sound waves into an area where the food waste disposer noise is to be controlled at an amplitude and frequency to at least cancel or mask the food waste disposer noise.

15. The food waste disposer system of claim 14 wherein the active noise source is configured to radiate the active noise sound waves at an amplitude and a frequency to both cancel and mask the food waste disposer noise.

16. The food waste disposer system of claim 14 wherein the active noise source is disposed to radiate the active noise sound waves into an interior of the food conveying section of the food waste disposer.

17. The food waste disposer of claim 16 wherein the active noise source has a portion that extends through a wall of a housing of the food conveying section and from which the active noise sound waves are radiated.

18. The food waste disposer system of claim 16 including a stopper receivable in a sink drain opening of a sink to which the food waste disposer is mounted, the active noise source disposed in the stopper.

19. The food waste disposer system of claim 14 wherein the active noise source is disposed to radiate the active noise sound waves into an interior of a tubular body of a sink flange to which the food waste disposer is mounted.

20. The food waste disposer system of claim 19 wherein the active noise source has a portion that extends through a wall of the tubular body of the sink flange and from which the active noise sound waves are radiated.

21. The food waste disposer system of claim 14 including a stopper receivable in a sink drain outlet of a sink to which the food waste disposer is mounted, the area being above an inlet at an upper end of the food waste disposer and the active noise source disposed in the stopper to radiate the active noise sound waves to the area above the inlet at the upper end of the food waste disposer.

22. The food waste disposer system of claim 14 wherein the active noise source is disposed to radiate the active noise sound waves in an interior of a cabinet in which the food waste disposer is disposed.

23. The food waste disposer of claim 22 wherein the active noise source is disposed in the cabinet.

24. The food waste disposer of claim 14 wherein the active noise sound waves are generated by a vibration transducer in contact with a wall of a sink to which the food waste is mounted and the active noise sound waves are generated by the vibration transducer vibrating the wall of the sink.

25. The food waste disposer of claim 14 wherein the active noise sound waves are generated by a vibration transducer in contact with a wall of a cabinet in which the food waste disposer is disposed by the vibration transducer vibrating the wall of the cabinet.

26. The food waste disposer of claim 14 wherein the active noise sound waves are generated by a vibration transducer in contact with a wall of a conveying housing of a food conveying section of the food waste disposer by the vibration transducer vibrating the wall of the conveying housing or by a vibration transducer in contact with a wall of a tubular body portion of a sink flange to which the food waste disposer is mounted by the vibration transducer vibrating the wall of the tubular body portion.

Description

DRAWINGS

[0028] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0029] FIG. 1 is a sectional view of a prior art food waste disposer;

[0030] FIG. 2 is an exploded view of a prior art mounting assembly for mounting a food waste disposer to a sink;

[0031] FIG. 3 is a sectional view of an upper portion of a food waste disposer system having active noise control with an active noise source disposed in a wall of a conveying housing of a food conveying section of the food waste disposer in accordance with an aspect the present disclosure;

[0032] FIG. 4 is a sectional view of an upper portion of a food waste disposer system having the active noise source disposed in a wall of a tubular body of a sink flange to which the food waste disposer is attached accordance with another aspect the present disclosure;

[0033] FIG. 5 is a sectional view of an upper portion of a food waste disposer system having the active noise source disposed in a stopper received in a drain opening of a sink to which the food waste disposer is mounted in accordance with another aspect the present disclosure;

[0034] FIG. 6 is a sectional view of an upper portion of a variation of the food waste disposer system of FIG. 5 in which the active noise source is disposed to radiate active noise sound waves to an area above an inlet at an upper end of the food waste disposer in accordance with another aspect of the present disclosure;

[0035] FIG. 7 is a perspective view of a food waste disposer system having an active noise source disposed in a housing attached to the motor section of the food waste disposer in accordance with another aspect of the present disclosure;

[0036] FIG. 8 is a perspective view of a food waste disposer system having an active noise source disposed in a cabinet in which the food waste disposer is disposed;

[0037] FIG. 9 is a perspective view of a food waste disposer system having active noise control in which active noise sound waves are generated by a vibration transducer in contact with a wall of a sink to which the food waste disposer is mounted in accordance with another aspect of the present disclosure; and

[0038] FIG. 10 is a perspective view of a food waste disposer system having active noise control in which active noise sound waves are generated by a vibration transducer in contact with a wall of a cabinet in which the food waste disposer is disposed in accordance with another aspect of the present disclosure

DETAILED DESCRIPTION

[0039] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0040] In accordance with an aspect of the present disclosure, active noise control is used to reduce noise of a food waste disposer. Active noise control can include noise masking and/or noise cancellation. Noise masking involves generating a broad spectrum noise field with a frequency content and amplitude that effectively “masks” or covers up annoying noises emanating from the food waste disposer. Noise masking does not actually reduce the amount of noise, but instead distracts the operator from being annoyed by the sound of the food waste disposer. Noise cancellation is the superposition of a canceling sound wave with the sound wave emanating from the disposer. The canceling sound wave is essentially the negative of the propagating sound wave (opposite phase) so that when the propagating sound wave and the canceling sound wave are superimposed, the result is a zero to low level sound.

[0041] Applying active noise control to the food waste disposer involves measuring the sound to be cancelled or masked, generating the appropriate cancelling or masking signal, and then playing that signal through a speaker located in or near the food waste disposer. In the case of effective global noise cancelling the noise is cancelled at the source (disposer) and this reduces the overall loudness at any location in the household. In the case of noise masking, it is preferable to minimize the amount of dynamics in the masking signal in order to reduce likelihood that the operator will notice its presence. The amounts of active noise canceling and sound masking can both be manipulated with a high degree of accuracy.

[0042] Referring to FIG. 3, a food waste disposer system 300 having active noise control is shown. Food waste disposer system 300 includes a food waste disposer 302 having an active noise source 304 that radiates active noise sound waves into an area where food waste disposer noise generated when a motor of the food waste disposer is running is to be controlled. Illustratively, food waste disposer 302 is the same as food waste disposer 100 except for the addition of active noise source 304 and the following discussion will focus on the differences. In the example of FIG. 3, a portion 306 of active noise source 304 extends through a wall 308 of conveying housing 110 of food conveying section 102 and radiates active noise sound waves 310 into an interior 312 of food conveying section 102 with the interior 312 constituting an area 313 in which the food waste disposer noise is to be controlled. Portion 306 is illustratively an end portion of active noise source 304 and will hereafter be referred to as end portion 306. Active noise source 304 is disposed in a protective housing 314 with a protective membrane 316 at end portion 306 of active noise source 304. Active noise source 304 is coupled to an active noise drive circuit 318 that drives active noise source 304. Active noise source 304 is illustratively an audio transducer and may for an example be an audio speaker but can be other types of audio transducers such as piezoelectric audio transducers. Active noise drive circuit 318 is for an example a circuit including a signal generator and audio amplifier that amplifies an output of the signal generator. In an aspect, active noise drive circuit is programmable as to frequency, amplitude, or both.

[0043] In an aspect, active noise circuit 318 adaptively programs itself to function in frequency ranges which are prevalent in the system. In an aspect, active noise circuit 318 utilizes feedback control, in an aspect, active noise circuit uses feed forward control, and in an aspect, active noise circuit utilizes a combination of feedback and feed forward control.

[0044] As an example and not by way of limitation, active noise circuit 318 is configured, such as by programming, to implement a control methodology commonly known to those of skill of the art as Filtered-X least means squared feedforward control. The Filtered-X indicates that a source signal is passed through an adaptive finite impulse response signal to form the control signal. Initially, the filter coefficients are set to zeros, and then the control algorithm adapts the filter to minimize the error signal at each step, which is how control of impulsive signals is achieved. The filter is illustratively designed to function in a certain frequency range, such as a 120 Hz peak or less than 1000 Hz.

[0045] With reference to FIG. 4, in an aspect, a food waste disposer system 400 has end portion 306 of active noise source 304 extending through a wall 402 of a tubular body portion 404 of sink flange 204 to which food waste disposer 100 is mounted. Active noise source 304 radiates active noise sound waves 310 into an interior 406 of tubular body portion 404 as shown in FIG. 4 with the interior 406 being an area 407 in which the food waste disposer noise is to be controlled.

[0046] With reference to FIGS. 5, in an aspect, a food waste disposer system 500 has an active noise source 502 disposed in a stopper 504 that is received in a sink drain outlet 506 of a sink 508 in which sink flange 204 to which food waste disposer 100 is mounted is received. It should be understood that stopper 504 is received in sink drain outlet 506 by being received in sink flange 204 which is received in sink drain outlet 506. In an aspect, active noise source 502 is disposed between protective membranes 512 that are also disposed in stopper 504. Active noise source 502 is illustratively also an audio transducer and is coupled to active noise drive circuit 318. In the aspect shown in FIG. 5, the active noise source 502 is disposed in stopper 504 to radiate active noise sound waves 310 into interior 312 of the food conveying section 102 of food waste disposer 100. In an aspect, stopper 504 is a stopper of the type described in U.S. Pat. No. 9,145,666 the entire disclosure of which is incorporated herein by reference.

[0047] In a variation of the food waste disposer system of FIG. 5, active noise source 502 disposed in stopper 504 radiates active noise sound waves 310 to an area 602 (FIG. 6) external to food waste disposer 100. In an aspect, area 602 is an area 604 above an inlet 109 at the upper end of food waste disposer 100 and the active noise source is disposed in stopper 504 to radiate active noise sound waves 310 into the area 604 above inlet 109.

[0048] With reference to FIG. 7, in an aspect, a food waste disposer system 700 includes a food waste disposer 702 having an active noise source 704 and active noise drive circuit 318 disposed in a housing 706 attached to motor section 106. It should be understood that housing 706 could be attached to other sections of food waste disposer 702, such as upper food conveying section 102 or central grinding section 104.

[0049] With reference to FIG. 8, a food waste disposer system 800 includes food waste disposer 100 mounted to a sink 804 with food waste disposer 802 disposed in a cabinet 806 with sink 804 received in a top of cabinet 806. An active noise source 808 is spaced from the food waste disposer 802 in cabinet 806 and radiates active noise sound waves 310 into an interior 810 of cabinet 806 with interior 810 being an area 811 in which the food waste disposer noise is to be controlled.

[0050] In each of the foregoing aspects, it should be understood that more than one active noise source can be used with the different active noise sources located at different ones of the above described locations.

[0051] In an aspect, vibration excitation could also be used to generate the cancelling or masking noise. Vibrational excitation of either the cabinet or sink can cause the cabinet or sink to radiate noise. Stainless steel kitchen sinks which are used in the majority of US households are effective radiators of sound. The sink itself acts as a speaker and when excited by a vibration signal, will radiate sound. Thus, in an aspect, an alternative means of creating a masking or cancelling signal for the operational noise of the food waste disposer is to use the structural response of the sink to a vibrational source as the source to generate the needed signal, use the structural response of the cabinet to a vibrational source as the source to generate the needed signal, or both. A drawback of this approach is that sink and cabinet characteristics are variable from installation to installation so the effectiveness of these alternatives may be site dependent. In this approach, an adaptive control method would be used and the adaptive nature of the control method will try to achieve noise cancellation within the means of the vibration source but there will be some range of system parameters (stiffness, damping) where the system would not be able to perform, but it will try to adapt to the site conditions as much as possible. FIGS. 9 and 10 show examples of the foregoing aspects.

[0052] With reference to FIG. 9, a food waste disposer system 900 has food waste disposer 100 mounted to a sink 902. Food waste disposer 100 is illustratively disposed in a cabinet 904 with sink 902 received in a top of cabinet 904. A vibration transducer 906 is in contact with a wall 908 of sink 902. Vibration transducer 906 is coupled to a vibration drive circuit 910. Vibration transducer 906, driven by vibration drive circuit 910, vibrates wall 908 of sink 902 at an applicable frequency to generate the active noise sound waves. Vibration transducer 906 is for example a piezoelectric transducer, but can be other types of transducers that vibrate in response to an electrical drive signal.

[0053] With reference to FIG. 10, a food waste disposer system 1000 has food waste disposer 100 mounted to a sink 902. Food waste disposer 100 is illustratively disposed in cabinet 904 with sink 902 received in the top of cabinet 904. A vibration transducer 906 is in contact with a wall 912 of cabinet 904. Vibration transducer 906 is coupled to vibration drive circuit 910. Vibration transducer 906, driven by vibration drive circuit 910, vibrates cabinet wall 912 at an applicable frequency to generate the active noise sound waves.

[0054] It should be understood that the vibration transducer could be located at locations other than wall 908 of sink 902 or cabinet wall 912. For example, vibration transducer 906 could be disposed in wall 308 of conveying housing 110 instead of active noise source 318 or in wall 402 of tubular body portion 404 of sink flange 204 (shown in phantom in FIG. 4). In these examples, wall 308 of conveying housing 110 or wall 402 of tubular body portion 404 of sink flange 204 are vibrated to generate the active noise sound waves.

[0055] It should be understood that in each of the above described aspects, the food waste disposer can have a layer of sound insulation such as sound insulation 148 (FIG. 1) or not have it.

[0056] It should be understood that active noise drive circuit 318 or vibration drive circuit 910 may be, be part of, or include an Application Specific Integrated Circuit (ASIC); an electronic circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor (shared, dedicated, or group) that executes code; a programmable logic controller, a programmable control system such as a processor based control system including a computer based control system, a process controller such as a PID controller, a digital signal processor, or other suitable hardware components that provide the described functionality or provide the above functionality when programmed with software implementing the logic described herein; or a combination of some or all of the above, such as in a system-on-chip. The term software, as used herein, may refer to computer programs, routines, functions, classes, and/or objects and may include firmware, and/or microcode. When it is stated that active noise drive circuit 318 or vibration drive circuit 910 performs a function, it should be understood that active noise drive circuit 318 or vibration drive circuit 910 is configured to do so such as by appropriate software, electronic circuit(s) including discrete and integrated logic, or combination thereof.

[0057] Applying active noise cancellation to the operational noise of a food waste disposer may make it feasible for either the manufacturer or the user themselves to select how loud they would like to the food waste disposer to be when operating. It is possible that the user may want to hear some low level noise from the disposer during operation so that they know it is working. Being able to customize the degree of active noise cancellation, particularly for the user, would make it possible to adjust the noise as activity in the home warrants. On the other hand, the manufacturer could tune the active noise cancellation so that the effectiveness is differentiated by model similar to current product differentiation in the disposer line. Further, masking noise could be introduced along with the active cancellation to mask higher frequency sounds which tend to be more difficult to actively attenuate. Similar to the active noise cancelling effectiveness, the spectral and temporal characteristics of masking noise could be manipulated by the manufacturer to further influence the operator's perception of the sound. Similarly, an operator selectable option to play music or some other type of sound over the noise of the disposer could be included to enhance the operator's awareness that the disposer was running and/or to mask the noise of the disposer.

[0058] Characteristics of the food waste disposer operational noise that make it suitable for active noise control are (1) on average the noise is tonal with dominating peaks less than 1000 Hz which is the most physically suitable frequency range for active noise cancellation, (2) the noise is time varying at a rate which is well within the active noise control controller adaptation rate and so can be tracked and cancelled in real time as the food waste disposer operates, and (3) an acoustic or vibration reference signal is available at the noise source which is coherent to the acoustic signal experienced or measured in the desired area of active noise cancellations.

[0059] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.