US2991018A - Noise reduction of food waste disposers - Google Patents

Description

July 4, 1961 T. E. JENKINS NOISE REDUCTION OF FOOD WASTE DISPOSERS Filed May 9, 1960 INVENTOR. VTHOMAS E. J'ENK\NS H 15 ATTORNEY United States Patent 2,991,018 NOISE REDUCTION OF FOOD WASTE DISPOSERS Thomas E. Jenkins, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed May 9, 1960, Ser. No. 27,778 4Claims. (Cl. 241-1005) The present invention relates to food waste disposal apparatus of the type having an electrically driven unit adapted to be mounted below the drain opening of the kitchen sink for grinding and discharging food waste into a sewer system, and particularly to a means of reducing the transmission of the noise generated by the disposer.

Several decades ago most kitchen sinks were manufactured of heavy cast iron that was provided with a top porcelain coating. At the present time almost all kitchen sinks are manufactured from thin sheet steel i.e. either cold rolled steel with a top porcelain coating or stainless steel. These sheet metal sinks are of relatively light gag metal and they operate in the manner of a vibrating sounding board 'when a waste disposer is mounted to the underside of the sink and large bones and other food Waste that are difficult to grind are handled by the disposer. Recent design changes have tended to increase the grinding efiiciency and the power of the disposers while at the same time making the units more compact. All of these changes also make the unit noisier in operation.

The present invention relates to a mass loading means for deadening the transmission of the noise of operating a food waste disposer supported beneath a kitchen sink.

Afurther object of the present invention is to provide a simple and inexpensive means for increasing the mass of a sheet metal sink.

A further object of the present invention is to provide a simple means for clamping a large heavy metal plate to the underside of a sheet metal sink that is adapted to support a food waste disposer to give the sink the effect of a cast iron sink insofar as noise transmission is concerned.

The present invention relates to a food waste disposer for use with a sheet metalsink. Such a sink includes a drain opening and there is a metal sleeve extending through the opening and supported therein. The disposer comprises a housing that includes a hopper, a grinding chamber, and a motor casing. The top of the hopper has an inlet opening for receiving water and waste material. Clamping members are provided for hanging the disposer housing from the sleeve. These clamping members include vertical adjusting screws which may be adjusted to hold a large relatively heavy metal plate centered around the sleeve and stressed against the underside of the sink. Cushions or other suitable bearing materials may be compressed between the sink and the outer extremities of the plate remote from the sleeve. This plate functions to increase the mass of the sheet metal sink thereby reducing vibrational noises in the sink.

My invention will be better understood from the following description taken in connection with the accompanying drawing and its scope Will be pointed out in the appended claims.

FIGURE 1 is a top plan view of a portion of a kitchen counter showing a sink mounted therein and a food waste disposer supported from the drain opening in a manner embodying the present invention.

and having a bottom wall 12 with a drain opening 13 below which a food waste disposer 14 may be supported as is seen in FIG. 2. Waste disposer 14 includes a housing comprising a hopper 15, a grinding chamber 16, and a motor casing 17, reading from top to bottom. The top portion of the hopper 15 forms an inlet opening for receiving water and waste material. The hopper is fastened to the top of the grinding chamber 16 and the waste will be delivered to the grinding chamber and shredded into fine particles where it will be discharged through a sewer connection 18 which is joined to a sewer line or septic tank system (not shown). The details of the waste disposer are not specifically illustrated because this invention has general utility in this art and it is not limited to any particular design of waste disposer.

It will be observed that the housing of the waste disposer 14 has a circular top inlet opening aligned with the sink drain opening 13, and that a metal sleeve 20 not only provides a passageway from the sink to the interior of the disposer but also supports the disposer. The sleeve 20 which is commonly referred to in the art as a sink flange is of tubular design with a large upper shoulder or flange 21 which is larger in diameter than the drain opening 13 so that the shoulder is hung from the bottom wall 12 of the sink thereby supporting the sleeve in the drain opening. The lower edge of the sleeve 20 has an enlarged head 22 as well as an inturned ledge or seat 23. This internal seat 23 supports an annular rubber member 24 which serves as the support means for a suitable drain stopper 25.

A support ring 26 is formed by two semi-circular segments (not shown) which are fastened together at a point on the sleeve above the enlarged bead 22. Formed on the upper end of the disposer housing or hopper is an outwar'dly projecting flange 28 which cooperates with a mounting ring 29 that encircles the housing and extends within an annular groove 30 in the throat of the hopper. Vertical adjusting screws 31 are threaded through the support ring 26 and are each provided with a nut 32 positioned on the lower end thereof. Moreover the lower end of each adjusting screw is provided with a screw driver slot 33 for turning the'screws to obtain the necessary adjustment. The mounting ring 29 is provided with a series of keyhole slots 34 (not shown in detail) so that the disposer housing can be hung from the nuts on the adjusting screws.

In order to assemble the disposer housing 14 to the sleeve 20, it is necessary to raise the housing until the nuts 32 extend through the largest portions of the keyhole slots of the mounting ring 29. Then by turning the disposer housing the mounting ring will be supported by the nuts 32. It is important that the adjusting screws 31 be raised to bear against the underside of the sink to prevent the disposer housing 14 from rocking from its support. One other feature in the mounting means is the use of a rubber gasket 35 between the support ring 26 and the upper flange 28 of the disposer housing in order to reduce the transmission of noises from the disposer through the mount and into the sink. This mounting means of the disposer from the sleeve in the drain opening is illustrated in detail in'the Brezosky et al. Patent No. 2,819,028 which is assigned to the same assignee as is the present invention. This mounting means is merely discussed in detail here for illustration purposes as one example of a suitable method of mounting, but it should not be considered as a limiting feature of the present invention.

The noise an appliance makes is becoming an increasingly important problem to the appliance engineer. Customers are now demanding that some appliances be quiet in operation and may in the future demand that others be much less noisy than they are at present by showing a marked preference in their buying habits. Unfortunate- 1y, most kitchen sinks being installed today are sheet 7 metal sinks of relatively thin gage so that the sink acts as a sounding board and reverberates whenever the food waste disposer is set in operation grinding hard food waste such as bones and corn cobs.

The present invention teaches the use of a large and heavy metal plate 40 which underlies the bottom wall 12 of the sink and is clamped against the sink to place the plate and sink under stress and increase the effective mass a be fitted in centered relation over the sleeve 20 to bear against the underside of the sink wall 12. Rubber pads 42 may be compressed between the metal plate 40 and the sink wall 12 adjacent the outer extremities of the plate and at a distance outside the adjusting screw means. These pads serve to insure firm bearing contact or pressure points between the plate and the sink wall and reduce the vibrational noises set up by the disposer during its operation. For instance, if one were to knock his knuckles against the bottom wall 12 of the sheet metal sink, the resulting sound would be a dull thud. If the heavy plate 40 were missing as in standard sink designs, then when a similar knocking test is made the sound would be rather tinny and loud. A typical metal plate that may be used is a plate of hot rolled steel A thick, 10" wide and 12 long. Rubber pads 42 may be used as the bearing contact means or a putty-like material such as Duxseal may be used as an alternative to temporarily glue the plate to the underside of the sink until the vertical adjusting screws 31 can be raised in place to hold the plate firmly against the sink.

In certain prior art designs the vertical adjusting screws have been provided to bear against a clamping ring of nearly the same size as the mounting ring 29. The applicants invention must be distinguished from such a small clamping ring in that the metal plate 40 is large enough to partially cover the bottom wall of the sink as is seen in dotted lines in FIG. 1. Also the sink and the plate are clamped together under stress. The plate 40 is heavy in weight to increase the mass of the sink and substantially reduce the loudness of the noise.

In any eifective program of noise control one must be able to compare the noise of present and previous models of appliances. This means that noise must be adequately defined and measured. Noise has many attributes such as loudness, pitch, time distribution, direction, etc. All of these factors contribute to the annoyance factor of the noise. At present there can be an agreement by a jury of peers on the loudness, but not on its absolute annoyance factor. It is believed that loudness is one of the chief components of the annoyance factor and therefore loudness which can be measured is the best index we have at present to compare the annoyance factor and predict the possible reaction of the customer to the noise of an appliance. A phon is the unit of loudness level and it is numerically equal to the sound pressure level in decibels relative to .0002 dyne/cm. of a 1,000 cycle pure tone which is judged by the listener to be equivalent in loudness. Loudness, S is measured in sones while the loudness level P is measured in phons. These elements are related according to the equation By definition the loudness of a simple tone of 1,000 c.p.s. 40 decibels above .0002 microbar is l sone. The loudness of a sound that is judged to be N times the 1 some tone is N sones.

it has been our experience that if a food waste disposer is mounted in an old house having a cast iron sink the unit of loudness of the noise generated by the disposer is in the order of 26 sones. When this same disposer is mounted in a sheet metal kitchen sink the loudness is between 110 and 120 sones. If elaborate precautions are taken, and special units are built with rubber hoppers, encapsulated motors, rubber sink mounts, rubber drain lines, and noise shields wrapped around the housing, the noise level can be reduced to approximately 60 sones. The use of the present invention on sheet metal sinks noise level can be reduced to approximately 60 sones. down to an amount .of about 28 sones which is approximately the loudness when a cast iron kitchen sink is used. In other words the present invention removes the problem of transmitted noise from a sheet metal sink as compared with a cast iron sink.

Modifications of this invention will occur to those skilled in this art and it is to be understood, therefore, that this invention is not limited to the particular embodiment disclosed but that it is intended to cover all modifications which are within the true spirit and scope of this invention as claimed.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Waste disposal apparatus for use with a sheet metal sink, said apparatus comprising a housing enclosing a grinding chamber that has an inlet opening for water and Waste material at the upper end thereof, a sheet metal sink, a sleeve adapted to be disposed in a drain opening of the sink, and clamping means for hanging the housing from said sleeve, said clamping means including a large relatively massive metal plate several times larger than the drain opening and centered around said sleeve and vertical adjusting screw means adjustable to fasten the sleeve in the sink and hold said metal plate around the sleeve and against the underside of the sink, and cushions compressed between the underside of the sink and the outer extremities of the plate at widely spaced points remote from the said sleeve and at distances outside the vertical adjusting screw means to increase the mass of the sheet metal sink and reduce vibrational noises set up by said apparatus during its operation.

2. Waste disposal apparatus for mounting under a sheet metal sink, a sink having a drain opening, a sleeve extending through the drain opening and supported therefrom, the disposal apparatus including a housing that encloses a grinding chamber below a hopper that has an inlet opening for receiving water and waste material at the upper end thereof, and releasable means for clamping the upper end of said housing to the lower end of the sleeve; the invention comprising a large relatively heavy metal plate adjacent the underside of the sink and being at least several times larger than the drain opening, adjusting means supported from the sleeve to clamp said plate to said underside of said sink, and non-metallic means at the outer extremities of the plate compressed between the heavy metal plate and the underside of the sink to form bearing points between the plate and the sink that are at distances outside the said adjusting means, the heavy metal plate being stressed against the bottom of the sink to add mass to the sheet metal sink and reduce the loudness of the noise created by the disposal apparatus and transmitted by the metal sink.

3. Means for clamping a large relatively heavy metal plate to the underside of a sheet metal sink for reducing the noise level of the sink, a sheet metal sink having a drain opening, a sleeve extending through said drain opening and supported therein, a waste disposal apparatus including a grinding chamber that has an inlet opening for receiving water and waste material at the upper end thereof, and means for clamping the upper end of the disposal apparatus to the lower end of said sleeve, said noise reducing means comprising a large relatively massive metal plate at least several times larger than the drain opening and vertically adjustable means bearing upwardly from said disposal apparatus and engaging the said large plate for holding the plate tightly against the underside of the sink, the metal plate covering a substantial part of the underside of the sink and in eifect constituting a part of the sink, the outer extremities of the plate having pressure points bearing against the underside of the sink at distances outside the said vertically adjustable means so as to increase the mass of the sink and reduce the tendency of the sheet metal to reverberate when the waste disposal apparatus is in operation.

4. Means for mounting a large heavy metal plate against the underside of a sheet metal sink as recited in claim 3 wherein the large metal plate covers a major portion of the underside of the sink and cushioning material is positioned between the sink and the outer extremities of the plate at the said pressure points to prevent metal contact between the parts at these points and reduce vibrational noises set up by said apparatus during its operation.

References Cited in the file of this patent UNITED STATES PATENTS Powers Aug. 8, 1950 Brezosky et al. Ian. 7, 1958

Images