Patent Abstract:
Disclosed herein is a vibration isolation gasket for mounting a food waste disposer to a sink that is at least partially molded onto a portion of the housing of the disposer, and preferably to the disposer&#39;s container cover. The vibration isolation gasket preferably includes a rubberized and integrally-formed gasket portion, sleeve portion, and over-molded portion. The gasket portion couples to the drain opening and may contain pleats to prevent food ejection from the disposer. The sleeve portion connects the gasket and over-molded portions, bears the weight of the disposer as it hangs from the sink, and acts as the primary structure for reducing vibration-induced noise. The over-molded portion is preferably molded onto the top and bottom of the container cover, which is in turns crimped to the remainder of the disposer housing.

Full Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to a food waste disposer, and more particularly to an over-molded vibration isolation gasket for mounting a food waste disposer to a sink.  
         BACKGROUND OF THE INVENTION  
         [0002]    Conventional food waste disposers are typically coupled to a sink by a mounting gasket, which is typically composed of rubber. The mounting gasket serves as the primary seal between the sink and the disposer and preferably also prevents the transmission of vibration from the disposer to the sink.  
           [0003]    In a prior art approach, and referring to FIG. 1, a conventional connecting assembly  40  and rubber mounting gasket  80  are used to attach the disposer to the sink  30 . The conventional connecting assembly  40  of FIG. 1 is substantially similar to that described in U.S. Pat. No. 3,025,007, which is incorporated herein by reference. The connecting assembly  40  includes a sink collar  34 , a seal plate  50 , a mounting flange  60 , and a support flange  70 .  
           [0004]    During assembly, the sink collar  34 , seal plate  50 , and mounting flange  60  are first secured in place around and underneath the sink  30 . More specifically, the sink collar  34  is positioned within the drain opening  32  of the sink  30 , leaving drain flange  36  to rest around the drain opening  32  as shown. During assembly, a gasket  54  and the seal plate  50  are slipped onto the sink collar  34  now appearing on the underside of the sink  30 . The mounting flange  60  is then slipped onto the collar  34 , and a snap ring  62  is seated within an annular recess on the collar  34 . Studs  66  are then screwed through threaded holes  64  in the mounting flange  60  until they contact the underside of a projecting surface of the seal plate  50 , thus pressing the gasket  54  between the seal plate  50  and the sink  30 . (Three studs  66  are normally used, but only one is shown in the cross section of FIG. 1). The mounting flange  60  has inclining flanges  68  onto which the remainder of the disposer (and associated hardware) can be screwed to fix the disposer into position underneath the sink, as will be explained in further detail later.  
           [0005]    The food waste disposer includes a container body  10  and a top container cover  20 , both preferably formed of metal. The container body  10  has an outwardly extending lip  12  to which edge  22  of the container cover  20  is crimped to seal the top of the disposer. The container cover  20  includes a housing collar  24  that forms the inlet of the disposer. During assembly, the support flange  70  is positioned on the housing collar  24  of the housing, and the mounting gasket  80  is press fit onto an outwardly extending lip  26  of the extruded collar  24  to hold the support flange  70  in place. As shown, the support flange  70  contains inwardly bent tabs  78 .  
           [0006]    When the disposer (with the support flange  70  in place) is to be affixed to the mounting flange  60  (already supported under the sink), the tabs  78  are positioned to meet with the inclining flanges  68  on the mounting flange  60 . Because the inclining flanges  68  are inclined, the tabs  78  (i.e., support flange  70 ) can be twisted with respect thereto, in effect, screw the disposer onto the mounting flange  60  to position the disposer in place underneath the sink  30 . To facilitate turning the support flange  70 , the support flange  70  is preferably formed with finger pads  76 . (Again, the support flange  70  normally contains three sets of tabs  78  and finger pads  76 , but only one such set is shown in the cross-section of FIG. 1). As the support flange  70  is twisted into place, it is brought closer to the mounting flange  60  due to the incline of inclined flanges  68 , thereby compressing the mounting gasket  80  therebetween, and further compressing the mounting gasket  80  against an inwardly projecting flange  38  of the collar  34 . In short, the flanges  60  and  70  compress the mounting gasket  80  to create a seal between the sink collar  34  and the housing collar  24  on the disposer. The mounting gasket  80  includes a plurality of pleats  87  formed across the drain opening to keep food waste from being ejected through the drain when the disposer is operating.  
           [0007]    Food waste disposers produce noise during operation that is caused by the operation of the motor and by the impacting of food waste against the housing of the disposer. These sources produce vibrations having a broad frequency spectrum. The vibration of the disposer can be transmitted into the sink through the connection of the disposer with the sink, which produces objectionable noise in and around the sink. Such noise is particularly evident, for example, in installations with relatively thin stainless steel sinks that act as excellent resonators.  
           [0008]    Unfortunately, the conventional connecting assembly  40  and mounting gasket  80  of FIG. 1 create a substantially rigid connection between the food waste disposer and the sink. In particular, vibration is hypothesized to travel through the solid metallic housing collar  24 , the compressed mounting gasket  80 , and the connecting assembly  40  to the sink  30 . Although vibration through the collar  24  is somewhat attenuated by the rubber material of the mounting gasket  80  that surrounds it, further dampening measures would be desirable, particularly if such measures did not significantly impact the structural integrity of the disposer or the manner in which it is affixed under the sink.  
           [0009]    The reader is referred to the following U.S. patents for further background concerning ways of minimizing operation noise of food waste disposers, all of which are incorporated herein by reference in their entireties: U.S. Pat. Nos. 2,743,875; 2,894,698; 2,945,635; 2,951,650; 2,965,317; 2,975,986; 3,801,998; 3,862,720; and 5,924,635.  
         SUMMARY OF THE INVENTION  
         [0010]    A vibration isolation gasket for mounting a food waste disposer to a sink is at least partially molded onto a portion of the housing of the disposer, and preferably to the disposer&#39;s container cover. The vibration isolation gasket preferably includes a rubberized and integrally-formed gasket portion, sleeve portion, and over-molded portion. The gasket portion couples to the drain opening and may contain pleats to prevent food ejection from the disposer. The sleeve portion connects the gasket and over-molded portions, bears the weight of the disposer as it hangs from the sink, and acts as the primary structure for reducing vibration-induced noise. The over-molded portion is preferably molded onto the top and bottom of the container cover, which is in turn crimped to the remainder of the disposer housing.  
           [0011]    The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    The foregoing summary, a preferred embodiment, and other aspects of subject matter of the present disclosure will be best understood with reference to a detailed description of specific embodiments, which follows, when read in conjunction with the accompanying drawings, in which:  
         [0013]    [0013]FIG. 1 illustrates a cross-sectional view of a conventional connecting assembly and mounting gasket according to the prior art;  
         [0014]    [0014]FIG. 2 illustrates a cross-sectional view of an embodiment of a vibration isolation gasket for mounting a disposer to a sink;  
         [0015]    [0015]FIGS. 3A-3D respectively illustrate side, perspective, top, and bottom views of the disclosed vibration isolation gasket of FIG. 2;  
         [0016]    [0016]FIGS. 4A-4B illustrate bottom views of embodiments of top container covers for the disclosed vibration isolation gasket of FIG. 2;  
         [0017]    [0017]FIG. 5 illustrates a cross-sectional view of a portion of the top container cover and over-molded portion for the disclosed vibration isolation gasket of FIG. 2;  
         [0018]    [0018]FIGS. 6A-6B respectively illustrate graphs of sink vibration spectrums and acoustic spectrums comparing a disposer having a conventional mounting gasket with a disposer having the disclosed vibration isolation gasket; and  
         [0019]    [0019]FIG. 7 illustrates a perspective view of another embodiment of a vibration isolation gasket. 
     
    
       [0020]    While the disclosed vibration isolation gasket is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. The figures and written description are not intended to limit the scope of the inventive concepts in any manner. Rather, the figures and written description are provided to illustrate the inventive concepts to a person of ordinary skill in the art by reference to particular embodiments, as required by 35 U.S.C. § 112.  
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0021]    In the interest of clarity, it is understood that not all of the features for an actual implementation of a vibration isolation gasket for mounting a food waste disposer to a sink are described in the disclosure that follows. It will be appreciated, of course, that in the development of any such actual implementation, as in any such project, numerous engineering and design decisions must be made to achieve the developers&#39; specific goals, e.g., compliance with mechanical and business related constraints, which will vary from one implementation to another. While attention must necessarily be paid to proper engineering and design practices for the environment in question, it should be appreciated that the development of a vibration isolation gasket for mounting a food waste disposer to a sink would nevertheless be a routine undertaking for those of skill in the art given the details provided by this disclosure.  
         [0022]    Referring to FIG. 2, an embodiment of a vibration isolation gasket  100  for mounting a food waste disposer (not shown) to a sink  30  is illustrated in a cross-sectional view. In contradistinction to the prior art discussed earlier, the disclosed vibration isolation gasket  100  is molded onto a portion of the disposer&#39;s housing, and preferably is molded onto a top container cover  120  of the housing. More specifically, gasket  100  contains three main rubberized portions in addition to the metallic container cover  120  that constitute the bulk of the gasket, viz., gasket portion  130 , sleeve portion  150 , and over-molded-portion  170 . Over-molded portion  170  is so named because that portion is molded over the metallic container cover  120 . More specifically, over-molded portion  170  preferably constitutes an upper over-mold  172  and a lower over-mold  174 .  
         [0023]    The rubberized portions  130 ,  150 , and  170  are preferably integrally formed over the container cover  120 , which can be accomplished by placing the container cover  120  inside a mold into which molten rubber is poured (or injected) and cured. The rubber material used for these portions preferably constitutes a flexible material, such as Nitrile rubber or ethylene propylene diene terpolymer (EPDM) rubber. The cover  120  is preferably formed of stainless steel, which is approximately 0.02 to 0.04-inch thick.  
         [0024]    As noted, it is preferable to form the molded portions  130 ,  150 , and  170  onto the container cover  120 , and then to affix the container cover  120  to the remainder of the disposer body. In this regard, the container cover  120  has an edge  122  that is crimped onto a lip  12  of an upper container body  10  of the disposer&#39;s housing. The edge  122  is approximately {fraction (1/8)}-inch long prior to its crimping to the lip  12 . A seal (not shown) is used between the attachment of the container cover  120  and the lip  12 . In an alternative arrangement, the top container cover  120  and upper container body  10  can be integrally formed, but such an integral arrangement is not preferred due to potential problems associated with molding the disclosed vibration isolation gasket  100  to such a large housing component. In particular, the upper container body  10  can act as a significant heat sink, which substantially increases the processing time. Consequently, it is preferred that the vibration isolation gasket  100  be molded onto a separate housing component, such as the top container cover  120  in the present embodiment.  
         [0025]    Once formed onto the container cover  120 , the support flange  70  is pressed over the deformable gasket portion  130  to facilitate connection of the disposer to the sink  30  as disclosed earlier in the Background section of this disclosure. As the details of the conventional connecting assembly  40  are substantially similar to those described in the Background section of the present disclosure, the structure and function of its components are not repeated here.  
         [0026]    The disclosed vibration isolation gasket  100  and top container cover  120  are illustrated in respective side, perspective, top, and bottom isolated views in FIGS.  3 A-D. (For illustrative purposes, the edge  122  of the container cover  120  is shown not crimped in FIGS. 3A-4B, as it would be before attaching to the container body of the disposer.) The gasket portion  130  mounts to the sink  30  with the connecting assembly  40  as just discussed. The sleeve portion  150  supports the weight of the disposer once it is positioned under the sink. The over-molded portion  170  as noted connects to the housing of the disposer, e.g., container cover  120 . All of these portions  130 ,  150 , and  170  work to reduce the transfer of vibration from the disposer to the sink. In addition, and as in the prior art, a plurality of pleats  137  are preferably formed within a central opening  136  of the gasket portion  130  to keep food waste from being ejected through the opening  136  when the disposer is operating. However, the use of pleats  137  in connection with the gasket portion  130  is not strictly necessary.  
         [0027]    As best shown in FIG. 3A, the sleeve portion  150  preferably has a smaller radial dimension than that of the gasket portion  130  such that it forms a recess in the disclosed gasket  100 . In addition, the sleeve portion  150  preferably has a smaller axial dimension than that of the gasket portion  130 . In one example of the disclosed gasket  100 , the sleeve portion  150  preferably has an outside diameter d 1  of approximately 3¼-inches and a height h 1  of approximately {fraction (1/4)}-inch, while the gasket portion  130  preferably has an outside diameter d 2  of approximately 4-inches and a height h 2  of approximately {fraction (1/2)}-inch. Preferably, the sleeve portion  150  has a wall thickness of about ⅛ to ¼-inch and more preferably 0.180-inch, but in any event should be thick enough to support the weight of the disposer (as much as 20 pounds). The disclosed molded gasket  100  is estimated to withstand pullout forces of about 100-lbs. or more.  
         [0028]    As noted, rubberized portions  130 ,  150 , and  170  are preferably molded to the container cover  120 , and several methods can be used to facilitate a good mechanical connection between them and the (usually) metallic cover  120 . In this regard, FIGS. 4A-4B illustrate the underside of the container cover  120  before the formation of rubberized components. In FIG. 4A, holes  126  or like structures are formed through the cover  120 , which allows the upper and lower over-molds  172  and  174  (not shown in FIGS. 4A-4B) to touch therethrough, improving the connection between the molded components and the cover  120 . The size, number, and placement of the holes  126  can vary, so long as the structural integrity of the disposer is not compromised. Preferably, twelve holes  126  having a diameter of about ¼-inch are formed about the central opening  124 . The holes  126  are arranged so that the outer edges of the holes  126  lie within a diameter of about 5¼-inches of the cover  120 , which represents the preferred outer diameter d 3  of the upper over-mold  172  discussed above. Alternatively, as shown in FIG. 4B, the central opening  124  in the cover  120  (normally circular as in FIG. 4A) can have an irregular shape with a plurality of notches  125  formed therein, which can strengthen the attachment of the extruded material of the disclosed gasket  100  to the container cover  120 . Preferably, eight, radial notches  125  each having a radius of about 0.150-inch are formed about every 45-degrees around the central opening  124 . In addition to having notches or another irregular shape, the opening  124  can have curled edges or like structures (not shown) to remove potentially sharp edges that could cut into the molded material, or could be formed with irregularity on its surfaces (e.g., nooks or tabs) to improve adhesion. Moreover, the container cover  120  can have ribs formed thereon or can have an extruded edge around the opening  124  to improve adhesion. Additionally, the surface of the cover  120  can be roughened, for example, by acid etching, prior to the overmolding process. Other processes and structures well known in the art of overmolding can be used as well, as one skilled in the art will appreciate.  
         [0029]    For the best adhesion, it is preferred that overmolded portion  170  has both an upper and lower over-mold  172 ,  174 , but in a given design either of these over-molds could be deleted. Were only one over-mold to be used, the use of lower over-mold  174  is preferred because the weight of the disposer would not tend to peel the container cover  120  away from the mold.  
         [0030]    The container covers  120  of FIGS.  4 A-B are shown with an annular rim  128  formed close to the periphery of the container cover  120 . The rim  128  is formed where the cover  120  engages the lip ( 12  in FIG. 2) of the container body and assists in sealing the cover  120  thereto. In another modification, and as best shown in FIG. 3D, the lower over-mold  174  of the molded portion  170  can have an optional seal  176  integrally formed about its periphery. The peripheral seal  176  can also be used to seal the attachment of the container cover  120  and lip  12  (FIG. 2) of the container body. A preferred arrangement of the optional seal  176  is shown in the cross-section of FIG. 5. The optional seal  176  preferably extends from the tapering lower-over mold  174  to the edge  122  of the container cover  120  and preferably has a thickness of approximately 0.01-inch. In addition, the optional seal  176  preferably has three annular rims  178  formed thereon for engaging the lip  12  (FIG. 2).  
         [0031]    As best shown in FIG. 3A, the upper over-mold  172  preferably has an outer radial dimension greater than that of the gasket portion  130  and almost as great as the top container cover  120 . In one example, the upper over-mold  172  can have an outside diameter d 3  of approximately 5¼-inches for a container cover  120  having an outside diameter d 4  of approximately 6-inches. The upper over-mold  172  has a preferable maximum height h 3  of approximately {fraction (1/8)}-inch. The lower over-mold  174  (FIG. 3D) has a similar outside diameter.  
         [0032]    The lower over-mold  174  can absorb impact noises created by food in the grinding chamber as well as diminish vibration. As best shown in FIG. 2, the lower over-mold  174  preferably has a height, e.g., height h 4  approximately {fraction (1/4)}-inch, which preferably is greater than the height of the upper over-mold  172 . Furthermore, the lower over-mold  174  preferably tapers from its central region on the gasket  100  towards its outside diameter. Similarly, the upper over-mold  172  also preferably tapers from its central region on the gasket  100  towards its outside diameter.  
         [0033]    The disclosed vibration isolation gasket  100  provides a flexible coupling between the disposer and the sink  30  that can reduce the transmission of the vibration to the sink, and accordingly reduce the noise at the sink and surrounding areas. Vibration isolation occurs primarily at the sleeve portion  150 . When installed, the sleeve portion  150  is in tension due to the weight of the disposer, which can be as high as 20 pounds, but this amount of tension is relatively low given the composition and dimensions for the sleeve portion  150 . Consequently, the sleeve portion  150  is still flexible under the tensile load and is able to absorb the vibration of the disposer caused by the motor and the impacting of food waste. Moreover, and in contradistinction to the prior art illustrated in FIG. 1, no hard metallic components akin to the housing collar  24  are present within or coupled to the gasket  100  to undesirably couple vibrations from the cover  120  to the support flange  70  and/or other structural components coupled to the sink. In addition, the over-molded portion  170  of disclosed gasket  100  also dampens vibration of the housing top, adding additional novelty when compared with the prior art illustrated in FIG. 1.  
         [0034]    Vibration in a disposer typically has a broad spectrum, and therefore the disclosed gasket  100  is preferably effective in isolating disposer vibrations over a wide frequency range. The disclosed gasket  100  has been shown through testing to be effective in reducing vibratory noise in a frequency range from 80 to 1000 Hz. These test results are shown in FIGS.  5 A-B, and compare vibration and acoustic spectrums of a disposer having a conventional mounting gasket with a disposer having the vibration isolation gasket of the present disclosure.  
         [0035]    Referring to FIG. 6A, sink vibration spectrum  202  is plotted for a 1-hp disposer rigidly mounted to a sink in the conventional manner, while sink vibration spectrum  204  is plotted for a 1-hp disposer mounted to the sink with the disclosed vibration isolation gasket of the present disclosure. The rigidly mounted disposer in spectrum  202  has a spectrum total of approximately 45.5-m/sec 2 , while the disposer mounted with the disclosed gasket of the present disclosure in spectrum  204  has a spectrum total of approximately 15.3-m/sec 2 . Consequently, the disclosed gasket reduces the transfer of the disposer&#39;s vibration to the sink by as much as a third. As evidenced in the spectrum  204 , the disclosed gasket  100  is particularly effective in reducing the transmission of vibration in the frequency range of about 200 to 650 Hz.  
         [0036]    In FIG. 6B, acoustic spectrums  212  and  214  illustrate the relative level of structural noise produced when the two mounting gaskets are used. A first acoustic spectrum  212  is plotted for the 1-hp disposer rigidly mounted to the sink in the conventional manner, and a second acoustic spectrum  214  is plotted for the 1-hp disposer mounted to the sink with the disclosed vibration isolation gasket of the present disclosure. As a result of the improved vibration isolation, the disclosed gasket produced less noise (spectrum  214 ) when compared to the conventional gasket arrangement (spectrum  212 ).  
         [0037]    [0037]FIG. 7 discloses yet another embodiment of a vibration isolation gasket  100 , which is illustrated in a perspective view. Those components that are similar in structure and function to the gasket described earlier are similarly numbered and are not repeated here. In contrast to previous embodiments, the gasket portion  130  of the present embodiment, while still molded to the container cover  120 , does not include a plurality of pleats formed in the opening  136 . Instead, the isolation gasket  100  of FIG. 7 includes a secondary baffle  140  that can be mounted in the drain opening (not shown) above the gasket portion  130 . The secondary baffle  140  can be similar to those disclosed in U.S. patent application Ser. No. 10/066,893, filed Feb. 4, 2002 and entitled “Baffle for a Food Waste Disposer to Reduce Noise and Associated Methods,” which is incorporated herein by reference in its entirety.  
         [0038]    The secondary baffle  140  has an annular body  142 , which can have a recessed rim  144  for engaging a complimentary rib formed on the drain opening (not shown). A plurality of pleats  147  are formed in an opening  146  though the secondary baffle  140 , which as in earlier embodiments reduces noise transmitted through the opening and prevents food waste from escaping. When the disclosed gasket  100  of FIG. 7 is installed on the drain opening, the bottom of the secondary baffle  140  preferably tightly fits into the drain opening and is positioned to rest on an annular surface or shoulder  138  of the gasket portion  130 . So configured, the secondary baffle  140  allows a user to readily clean or replace the secondary baffle  140  if needed without having to remove the mounting gasket and/or otherwise disassemble or disconnect the disposer from under the sink. Because the pleats  147  in the baffle  140  are relatively thin and subject to wear and tear, this embodiment is believed particularly user-friendly.  
         [0039]    In contrast to prior art solutions, the disclosed over-molded vibration isolation gasket does not considerably increase the distance between the disposer and the sink, which might otherwise require a number of modifications to the plumbing to be connected to the disposer. Furthermore, the disclosed over-molded vibration isolation gasket minimizes the number of mechanical couplings needed to install the disposer, which reduces the possibility of an improper installation. Moreover, manufacturing of the disposer is simplified because the mounting gasket and container cover are integrated into a single piece. Other benefits are evident to those of ordinary skill in the art.  
         [0040]    The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants or defined in the appended claims. In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. It is intended that the inventions defined by the appended claims include all modifications and alterations to the full extent that such modifications or alterations come within the scope of the appended claims or the equivalents thereof.

Technology Classification (CPC): 4