Patent Publication Number: US-9427114-B2

Title: Magnetic drain stopper assembly and method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Provisional Patent Application No. 61/497,571 filed Jun. 16, 2011, the entire disclosure of which is hereby incorporated by reference and relied upon. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     A drain stopper basins, and more specifically a magnetically actuated drain stopper. 
     2. Related Art 
     Basins, bathtubs, sinks and other varieties of receptacles (hereinafter collectively “basins”) are used in various applications to hold water or other liquids. Basins often include a drain passage through which liquid retained in the basin can be purged. Typically, the opening to the drain passage can be selectively closed by positioning a stopper in or over the opening. In many common configurations, the stopper is manually actuated through a lever-operated linkage to lift the head of the stopper away from the opening so that liquid (e.g., water) can run by gravity into the drain passage. Examples of prior art drain stopper assemblies manually actuated through a lever-operated linkage may be found in U.S. Pat. No. 6,341,391 to Cheng, issued Jan. 29, 2002 and U.S. Pat. No. 6,484,330 to Gray et al., issued Nov. 26, 2002.  FIG. 1  illustrates a prior art basin and drain stopper assembly of the type actuated manually through a lever-operated linkage. 
     While prior art drain stopper assemblies like that shown in  FIG. 1  are functional, all share the common trait of a control rod end positioned inside the drain passage.  FIG. 2  is a view looking down the drain passage from above a basin, and showing the typical control rod end disposed to engage the stopper (not shown). This protruding end of the control rod is in the direct flow of liquid as it drains from the basin, thus making the rod end prone to catch and retain debris which, over time, can build up to eventually clog the drain. Moreover, the protruding control rod end impedes easy access to the P-trap in the drain passage below where clog tend to reside. Thus, an attempt to dislodge a clog in the P-trap with a snake or hook through the drain passage opening will be met with opposition by the control rod end. Still further, the control rod penetrates the drain pipe usually through a spherical compression joint, creating a potential leak path. 
     To address some of the shortcomings of prior art drain stopper assemblies like that shown in  FIG. 1 , the prior art has also taught to fashion a magnetically actuated drain stopper assembly. Examples of these types of devices may be found in U.S. Pat. No. 5,208,921 to Nicoll, issued May 11, 1993 and U.S. Pat. No. 5,640,724 to Holmes, issued Jun. 24, 1997. Such devices utilize a specially configured stopper having a magnet attached to its lower guide section. This stopper magnet interacts with a driver magnet supported outside the drain pipe. Magnetic flux interactions between the stopper and driver magnets cause the stopper to lift when the driver magnet is pulled up and to fall when the driver magnet is lowered. One particular advantage of a magnetically actuated drain stopper assembly is evident from  FIG. 3  which is a top view of a drain passage as in  FIG. 2  but notable by the absence of any protruding control rod end. The drain passage of a magnetically actuated drain stopper assembly is clear of any internal obstruction, thereby facilitating the drainage of liquids from the basin without exacerbating clogs, enabling unimpeded access to the P-trap with a snake or hook through the drain passage opening, and the absence of additional potential leak paths from a penetrating control rod. 
     Most if not all prior art style magnetically actuated drain stopper assemblies are configured so that the external driver magnet(s) is mounted on the drain pipe to slide linearly up and down. These are designed to maintain a relatively constant spacing between the driver and stopper magnets. In other words, there is a one-to-one (1:1) corresponding movement of the stopper in relation to the displacement of the driver magnet. This one-to-one relationship has many disadvantages. If the operator pulls upwardly too rapidly on the driver magnet, they can overcome the stopper magnet so that it does not lift. Stronger magnets than otherwise necessary may be used to help prevent this condition. Furthermore, a sliding motion is difficult to maintain in proper working order over a long period of time. The underside of a basin is typically clamp and neglected for long periods of time so that dirt build-up can go undetected. Mechanical systems that operate in this environment must be robust and not prone to malfunction in dirty conditions. 
     Thus, there is a need in the art for an improved magnetic stopper assembly for a basin drain that provides easier and greater access to the drain, that functions mare reliably, and that is not prone to malfunction. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a drain stopper assembly for a drain pipe defining an internal drain passage, the drain passage having an upper entrance leading into the drain passage. A stopper is disposed for movement with respect to the upper entrance away from and toward a sealed condition to prevent the passage of liquid into the drain passage. The stopper includes a stopper magnet that produces an electromagnetic field. A driver magnet is situated external to the drain pipe. The driver magnet produces at least one electromagnetic field that generates a repellant electromagnetic field with respect to the stopper magnet. A curvilinear actuator is disposed external to the drain pipe and operatively supports the driver magnet for movement along a curved path toward the stopper magnet so that the electromagnetic fields interact with one another to induce movement of the stopper away from the sealed condition. 
     The invention also contemplates a method of moving a drain stopper between sealed and unsealed conditions. According to the method, a drain pipe has an upper entrance. A stopper is positioned in the upper entrance, and includes a stopper magnet that produces an electromagnetic field. A driver magnet is situated external to the drain pipe. The driver magnet produces at least one electromagnetic field. The driver magnet is moved along a curved path toward the stopper magnet to induce movement of the stopper away from the upper entrance. 
     An advantage of the present invention is that the curvilinear motion of the driver magnet functions more reliably than prior art designs and is not prone to malfunction even in adverse operating conditions that experience long periods of neglect. Manual control of the driver magnet is such that an operator is less likely to overtake the stopper magnet when raising the stopper. A further advantage is that the curvilinear motion of the driver magnet easily and reliably works with an existing faucet lift rod without having to use any special lubricants. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appended drawings, wherein: 
         FIG. 1  is an exemplary prior all lavatory sink and drain assembly, with the sink basin portion shown in partial cross-section to illustrate the drain stopper controlled by a mechanically linked push rod; 
         FIG. 2  is a top view of a prior art drain pipe leading from a sink basin, illustrating the obstruction created in the drain pipe by the drain stopper control linkage; 
         FIG. 3  is a view of a drain pipe leading from a sink basin as in  FIG. 2 , but showing the unobstructed passage enabled by the present invention; 
         FIG. 4  is a perspective view of a magnetically actuated stopper according to one embodiment of the invention; 
         FIG. 5  is a bottom view of the stopper as taken generally along lines  5 - 5  in  FIG. 4 ; 
         FIG. 6  is a perspective view of a magnetically actuated stopper and drain assembly according to a first embodiment of the invention with the stopper depicted in a lifted or raised condition to allow the drainage of fluids into the drain pipe; 
         FIG. 7  is a side view of the first embodiment of the invention showing the stopper in a lifted or raised condition; 
         FIG. 8  is cross-sectional view taken generally along lines  8 - 8  in  FIG. 7 ; 
         FIG. 9  is cross-sectional view taken generally along lines  9 - 9  in  FIG. 8 ; 
         FIG. 10  is a side view as in  FIG. 6  but showing the stopper in a lowered condition; 
         FIG. 11  is cross-sectional view taken generally along lines  11 - 11  in  FIG. 10 ; 
         FIG. 12  is cross-sectional view taken generally along lines  12 - 12  in  FIG. 11 ; 
         FIG. 13  is a perspective view of a magnetically actuated stopper and drain assembly according to a second embodiment of the invention with the stopper depicted in a lifted or raised condition to allow the drainage of fluids into the drain pipe; 
         FIG. 14  is a view as in  FIG. 13  but showing the stopper in a lowered condition; 
         FIG. 15  is a perspective view of a magnetically actuated stopper and drain assembly according to a third embodiment of the invention; 
         FIG. 16  is a side view of the third embodiment of the invention showing the stopper raised in solid lines and lowered in broken lines; 
         FIG. 17  is a simplified cross-sectional view through a bath tub drain assembly illustrating a fourth alternative embodiment of the invention with the stopper in a lowered condition; 
         FIG. 18  is a view as in  FIG. 17  with the stopper in a raised condition; 
         FIG. 19  is an enlarged, simplified view through a bath tub drain assembly illustrating a fifth alternative embodiment of the invention; and 
         FIG. 20  is a simplified view of an optional drain cover for use in connection with a stopper of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the  FIGS. 3-12 , wherein like numerals indicate like or corresponding parts throughout the several views, a drain stopper assembly according to a first embodiment of the invention is generally shown at  30 . The drain stopper assembly  30  is adapted for use in conjunction with a drain pipe  32  defining an internal drain passage  34 . An upper entrance  36  leads into the drain passage  34 . As perhaps best shown in  FIG. 6 , the drain pipe  32  is adapted to be mounted within an opening in a basin  38  so that its upper entrance  36  can receive water or other liquids from the basin  38 . 
     A push rod  40  ( FIG. 1 ) is disposed for manipulation in a generally up and down path by a user. The lower end of the push rod  40  may be joined to an adjustable interface member  42 , which in turn connects with the distal end of a control rod  44  of the stopper assembly  30 . 
     The assembly  30  includes a stopper, generally indicated at  46 . The stopper  46  is disposed for movement with respect to the upper entrance  36  toward and away from a sealed condition. In a raised or lifted condition ( FIGS. 6 and 7 ), water is free to escape from the basin  38 . However in the sealed condition ( FIG. 10 ) water is trapped in the basin  38 . The stopper  30  includes a head  48 , which may be circular in shape and made of clad or unclad plastic or other suitable material. The head  48  may be fashioned with or without an O-ring seal  50  to help establish a water-tight seal with respect to the basin  38  and/or the upper entrance  36  of the drain passage  34 . A guide section  52  depends from the head  48  to help control or stabilize movement of the stopper  46  between its raised and lowered (i.e., sealed) conditions. The guide section  52  is preferably made from plastic, but other materials (preferably non-ferromagnetic) can be used. The guide section  52  has a lower distal end  54  spaced apart from the head  48 , and may take many alternative forms. In the illustrated examples, the guide section  52  comprises a plurality of longitudinally extending fins  56 . 
     The stopper  46  is fitted with a stopper magnet  58  that produces an electromagnetic field of sufficient strength. Preferably, the stopper magnet  58  is of the permanent magnet type, and more specifically still of the rare-earth type which are known to produce significantly stronger magnetic fields than other types such as ferrite or alnico magnets. The magnetic field typically produced by rare-earth magnets can be in excess of 1.4 teslas. However, it will be appreciated that stopper magnet  58  could be fashioned from any type of permanent magnets (rare earth and weaker magnets) as well as from electromagnets. In the illustrated embodiment, the stopper magnet  58  disposed more or less centrally in the guide section  52  adjacent it distal end  54 . Attachment can be accomplished by any suitable technique, including over-molding, bonding, snap-fit, and the like. The stopper magnet  58  can be a single, unitary, monolithic element or a congregation of discrete magnet parts held in fairly close proximity to achieve functional unity. 
     The assembly  30  also includes a driver magnet, generally indicated at  60 , situated external to the drain pipe  32 . The driver magnet  60  produces at least one electromagnetic field that generates a repellant electromagnetic field with respect to the stopper magnet  58  so as to induce movement of the stopper  46  away from its sealed condition. That is, the driver magnet  60  is used to push or lift the stopper  46  away from the upper entrance  36  of the drain pipe  32  so that water can exit the basin  38 . The driver magnet  60  is also preferably of the permanent magnet type, and more specifically still of the rare-earth type which includes both neodymium magnets and samarium-cobalt magnets. However, other magnet types can be used, including non-rare earth permanent magnets and electro-magnets if desired. 
     A curvilinear actuator, generally indicated at  62 , operatively supports the driver magnet  60  for movement along a curved path toward the stopper magnet  58  so that their respective electromagnetic fields interact in a repelling manner to induce movement of the stopper  46  away from its sealed condition. In other words, as the curvilinear actuator  62  moves the drive magnet  60  closer to the stopper magnet  58 , the interacting magnetic forces cause the stopper  46  to elevate thus opening an egress for liquids to flow into the drain pipe  32 . As shown in  FIGS. 6-12 , the curvilinear actuator  62  is disposed external to the drain pipe  32 . Preferably, the curvilinear actuator  62  is formed in a generally U-shaped configuration ( FIG. 8 ) defined by spaced apart legs  64  connected though a common base  66 . The base  66  may have a cylindrical configuration so that its outer surface can function as a hinge. The legs  64  are moveable to a position on opposite sides of the drain pipe  32  as shown in  FIGS. 6-8 , in which the stopper  46  is induced to raise away from the upper entrance  36 . 
     The driver magnet  60  may take any of various forms suitable to motivate movement of the stopper  46  away from its sealed condition. In the first embodiment of the invention illustrated in  FIGS. 6-12 , the driver magnet  60  is comprised of a pair of driver magnet halves  65  spaced apart from one another and disposed on opposite exterior sides of the drain pipe  32 . One driver magnet half  65  is disposed on one of the legs  64  and the other driver magnet half  65  is disposed on the other leg  64 . In alternative examples, the driver magnet  60  may comprise only one strategically located magnet, or several strategically located magnets. 
     The assembly  30  includes a hinge bracket  68  adapted for attachment to the drain pipe  32 . Although  FIGS. 6-12  suggest a fixed attachment between the hinge bracket  68  and exterior surface of the drain pipe  32 , a vertically adjustable connection may be preferred in some cases to allow line-tuning of the placement of the driver magnets  60  relative to the stopper magnet  58 . The hinge bracket  68  is shown here as a short cylindrical section sized to receive the cylindrical base  66  of the curvilinear actuator  62 . As such, the curvilinear actuator  62  is able to pivot inside the hinge bracket  68  while the legs  64  scribe an arcuate path. And more specifically, the hinge feature is disposed in a generally horizontal plane so that the curvilinear actuator swings in a generally vertical arc in direct response to up and down movement of the push rod  40 . The driver magnet halves  65  thus trace a generally circular and vertical arc as they are moved by the operator. Those of skill in the art will appreciate alternative constructions for supporting the driver magnets  60  for movement in a non-linear path. These alternative constructions may or may not include a fixed hinge-like arrangement as shown in  FIGS. 6-11 . In one alternative example, the hinge bracket may extend like a fin or flange from the drain pipe  32  and support a simple pin or axel to allow the driver magnets  60  to swing in an arc toward and away from the stopper magnet  58 . Of course, many alternative constructions are possible. 
     The control rod  44  extends radially from the base  66  opposite the legs  64 . A slot  70  in the hinge bracket  68  accommodates the control rod  44  so that the curvilinear actuator  62  is permitted to pivot back and forth approximately 90 degrees. The slot  70  also traps the control rod  44  to help maintain the orientation of the curvilinear actuator  62  relative to the drain pipe  32 . As previously described, the control rod  44  is mechanically linked to the push rod  40  so that a user/operator remotely controls rotation of the curvilinear actuator  62  by pulling up on or pushing down on the push rod  40 . When art operator pulls up on the push rod  40 , the control rod  44  is lifted causing the curvilinear actuator  62  to rotate to the position shown in  FIGS. 10-12 . In this condition, the repelling forces of the driver magnet  60  are sufficiently far away from the stopper magnet  58  so that it cannot overcome the weight force of the stopper  46 . Gravity thus returns the stopper to its sealed condition. However, when the operator pushes down on the push rod  40 , the control rod  44  is rotated downwardly causing the curvilinear actuator  62  to rotate to the position shown in  FIGS. 6-9 . The driver magnet halves  65  carried in the legs  64  are simultaneously brought into proximity with the stopper magnet  58 , with the repelling interaction overcoming the opposing gravitation force and inducing elevation of the stopper  46 . 
     The driver magnet  60  may include one or more supplemental magnets  72  carried directly on the base  66  to induce movement of the stopper  46  away from its sealed condition. The supplemental push-up magnet  72  is preferably of the permanent magnet type, and more specifically still of the rare-earth type which includes both neodymium magnets and samarium-cobalt magnets. However, it will be appreciated that the supplemental magnet  72  could be fashioned from any type of permanent magnets (rare earth and weaker magnets) as well as from electromagnets. The supplemental push-up magnet  72  is shown in combination with the driver magnet halves  65  in  FIGS. 6-12 , however satisfactory results may be attainable with only the supplemental push-up magnet  72 , or with multiple individual magnets carried on the base  66 . 
     If gravitational force is not sufficient to return the stopper  46  to its sealed condition when the one or more driver magnets  60  are swung down, added assistance may be provided by way of one or more draw down magnets  74  positioned with respect to the stopper magnet  58  to induce movement of the stopper toward the sealed condition. The draw down magnet  74  is also preferably of the rare-earth, permanent magnet type. In the first embodiment of  FIG. 12 , the draw down magnet  74  is shown disposed in the base  66  circumferentially offset from the supplemental push-up magnet  72 . Depending on the placement and orientation of the draw down magnet  74  with respect to the stopper magnet  58 , the magnetic field flux interaction may operate to either urge the stopper  46  downwardly through magnetic attraction or magnetic repulsion. In other words, if when the curvilinear actuator  62  is rotated down the draw down magnet  74  is located below stopper magnet  58 , then a magnetic attraction force is needed to pull the stopper  46  more tightly toward the sealed condition. On the other hand, if when the curvilinear actuator  62  is rotated down the draw down magnet  74  is located above stopper magnet  58 , then a magnetic repelling force is needed to push the stopper  46  toward its sealed condition. 
     The curvilinear actuator  62  is particularly effective in a magnetically levitated stopper  46  configuration. Unlike prior art systems in which the spacing between driver and stopper magnets was generally locked into a 1:1 relationship by the linear sliding mechanism, the present invention takes advantage of a motion multiplier effect in which the driver magnets  60  are moved in a compound trajectory laterally as well as longitudinally so that the magnetic fields of the respective magnets  58 ,  60  interact in a non-linear relationship vis-à-vis the manual input motion of the push rod  40 . This configuration facilitates the use of stronger magnets that can be quickly moved far apart when returning the stopper  46  to it sealed condition. The curvilinear actuator also enables more robust structures that are not as prone to malfunction when operated in damp environment&#39;s and neglected for long periods of time. Furthermore, the curvilinear actuator  62  is easily and inexpensively manufactured. 
     Referring now to  FIGS. 13 and 14 , a second embodiment of the present invention is depicted. In this embodiment, wherein like reference numerals offset by 200 are used to indicate like or corresponding parts, the drain pipe  232  includes an offset section  276  immediately below the stopper magnet  258 . In this embodiment, the curvilinear actuator  262  is located along the offset section  276  so that its base  266  is positioned underneath the stopper magnet  258 . The flanking legs of the preceding embodiment are omitted here, with the driver magnet  260  comprising only a supplemental push-up magnet  272 . This orientation of the curvilinear actuator  262  relative to the stopper magnet  258  requires the optional the draw down magnet  274  (if used) to be oriented so that its magnetic field flux operates to pull the stopper  46  downwardly through magnetic attraction. By locating the driver magnet  260  directly underneath the stopper magnet  258 , a more efficient interaction of the magnetic flux can be achieved thereby improving the displacement force of the driver magnet  260  so that the legs can be omitted. Of course, if additional lifting force is needed or desired, flanking legs can be added to this embodiment of the curvilinear actuator  262  as well. 
       FIGS. 15 and 16  illustrate a third embodiment of the present invention. In this embodiment, wherein like reference numerals offset by 300 are used to indicate like or corresponding parts, the drain pipe  332  takes the traditional straight form, but the curvilinear actuator  362  includes a pair of opposing bases  366 ,  366 ′ supported in respective hinge brackets  368 ,  368 ′. The two opposing bases  366 ,  366 ′ are mechanically connected for synchronized rotation via an interconnecting drive belt  378 . A control rod  344  extends from only one of the bases  366  for connection to the push rod (not shown) as described above. Articulation of the one control rod  344  causes the opposing base  366 ′ to rotating in an equal but opposite directions within its hinge bracket  368 ′. The driver magnet  360  in this embodiment includes only supplemental push-up magnets  372 ,  372 ′ as in the immediately preceding embodiment, with flanking legs again being omitted here. It should be appreciated, however, that if additional lifting force is needed or desired, flanking legs can be added to this embodiment one or both of the bases  366 ,  366 ′. Depending on the placement and orientation of the optional draw down magnets  374 ,  374 ′ (if used) the magnetic field flux interaction with the stopper magnet  358  may operate either through magnetic attraction or magnetic repulsion. Alternative mechanical mechanisms may be substituted for the interconnecting drive belt  378  in order to achieve synchronized mirror-like rotation of the two bases  366 ,  366 ′. For but one example, meshing gears can be used. 
     A fourth embodiment of the present invention is shown in  FIGS. 17 and 18  illustrating a bathtub application. In this embodiment, like reference numerals offset by 400 are used to indicate like or corresponding parts. Because the typical bathtub drain pipe  432  has a sharp bend shortly below its upper entrance  436 , the curvilinear actuator  460  can be located directly below the stopper magnet  458 . This embodiment also illustrates the dimensional and proportional adaptability of the present invention to suit different basin  438  types and applications. 
       FIG. 19  illustrates a fifth embodiment of the invention wherein like reference numerals offset by 500 are used to indicate like or corresponding parts. As in the immediately preceding embodiment, the invention is shown in the exemplary application of a bathtub, it being understood however that other basin  538  types and applications may be applicable. Here in the curvilinear actuator  560  is supported for rotation in a generally horizontal plane. Manipulation of the push rod or other actuating lever feature (not shown) cases the control rod  544  to pivot the plate-like base  566  about a hinge bracket  568  which is shown here in the form of a simple axle. All of the principles and advantages of the invention as described in connection with the preceding embodiments are applicable here as well. Some applications of the invention may be more favorably disposed to a curvilinear actuator  560  constructed in this design as compared with the preceding variations. As shown in phantom lines, and optional draw-down magnet  574  may be used here with its magnetic field flux oriented to attract the stopper magnet  558 . 
     In  FIG. 20 , an optional feature of the present invention is depicted in the form of a magnetic drain cover, general indicated at  80 . This drain cover  80  can be used in connection with any of the disclosed embodiments of the invention. The drain cover  80  includes flange  82  adapted for engagement with the basin  38  and/or the upper entrance  36  of the drain pipe  32 . The flange  82  can simply rest in position, or be retained through a friction/force fit, or screw in place, or by other means be located in position shown. A screened or otherwise perforated side wall  84  extends upwardly from the flange  82 . Water (or other liquid contained in the basin  38 ) can pass through the side wall  84  upon egress from the basin  38 . The drain cover  80  includes a cap  86 . In situations whether a relatively large quantity of liquid is drained rapidly from the basin  38 , the drain cover helps route the exiting flow of liquid to the underside of the stopper head  48  so that the fluid flow does not end to pull the stopper  46  down toward the sealed condition. In other words, when the stopper  46  is lifted to the position shown in phantom in  FIG. 20 , the head  48  is placed in the lee formed by the cap  86  so that water pressure in the exiting flow tends to help keep the stopper  46  lifted. In this embodiment, the head  48  of the stopper  46  may further be magnetically attracted to the cover  86  with a light magnetic attraction force. When the stopper  46  is raised to the position shown in  FIG. 20 , the light magnetic attraction force further helps retain the stopper  46  in the lifted position. However, the attraction force will not be so strong as to thwart return of the stopper  46  to its sealed condition upon demand. 
     The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and fall within the scope of the invention.