Floor sink strainer assembly

A strainer assembly for use with an indirect waste receptor comprising an internally threaded, expandable gasket member sized to be insertable into the indirect waste receptor discharge tube operatively connected to a building drain system drain pipe; a rigid support structure forming an externally threaded wall to operatively mate with the gasket member in a manner to expand the gasket member body into sealing contact with the discharge tube or drain pipe and having a spoke member extending across a rigid support structure passageway with a vertical opening in its center section; a strainer having a screw opening alignable with the spoke member center section opening; and a screw seatable in the screw opening and having a length to operative attach to the center section opening for affixing the strainer to the rigid support structure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates in general to strainers, and more particularly to strainers that can be utilized with floor drains and indirect waste receptors, such as floor sinks.

2. Prior Art

In most buildings there will be a variety of plumbing fixtures that are supplied with water or which receive or discharge liquids or liquid-borne wastes. To assist in removal of liquid waste from these plumbing fixtures, there may be one or more indirect waste receptors, such as a floor sink, that will indirectly receive their liquid waste through an air gap. Other indirect waste receptors include mop receptors, service sinks, standpipe drains having integral air gaps, and other similar assemblies. The indirect waste receptors will then operatively connect to the building drain system, such as through a drain pipe, which in turn will be operatively connected to an outside building sewer system. In addition, buildings are likely to be constructed having floor drains intended for the purposes of the collection and disposal of waste water used in cleaning the floor, as well as for the collection and disposal of accidental spillage to the floor. Typically, such floor drains are provided with floor level strainers to prevent large solid objects from entering the floor drains. These floor drains are also operatively connected to a drain pipe forming part of the building drain system. Such floor sinks and floor drains have been used for many years in a wide variety of facilities such as commercial kitchens and laundries to collect liquid waste from a plumbing fixture or collect waste water used in the cleaning the floor or spillage which may have accidently spilled on the floor.

In addition to the liquid and small solid waste material, other larger solid materials, such as forks, spoons and other cooking utensils, as well as tin cans and plastic lids may be dropped on the floor. In too many cases these materials will be swept into the floor sinks or, if the floor level strainer has been removed, into the floor drains. Unless prevented many of these materials will enter the drain pipe forming part of the building drain system where they can become stuck and eventually create a blockage in the building drain system and/or even the sewer system when the two systems are operatively connected. Such blockage can prevent the liquid and smaller solid waste materials from passing through the drain pipe to the sewer system. When this occurs it is necessary to attempt to remove from the building drain system the material that has created the blockage. This is not only time consuming, but in many instances not possible without breaking up and tearing out sections of the concrete flooring to permit access to the area of that the drain pipe is blocked.

To prevent the blockage of the building drain system, a variety of strainers have been designed to either fit in the floor sink well or over the floor drain opening to prevent the larger solid objects from entering into the drainage tube or the drain pipe. Three principal problems exist with many of these strainers. First, the strainers must be easily, but securely fixed in a sealing position, yet quickly and easily removable should it become necessary to access the discharge pipe. Second, the strainers can not form an obstacle above the floor surface that might cause persons working around the floor sink or drain to trip and fall. Thirdly, the strainers must be tamper resistant to prevent unauthorized workers from removing the strainers.

To overcome these designs obstacles, various strainer configurations have been proposed. Examples of such prior art configurations are disclosed in U.S. Pat. No. 6,092,244; U.S. Pat. No. 6,330,724; and U.S. patent application Ser. No. 12/050,198 (Publication No. 2008/0295236). However, despite the advancement in the prior art there remains in the industry a need for a strainer for use in a floor sink or floor drain that is easy and quick to install, that forms a sealing arrangement with the drain pipe or the drainage tube, that effectively blocks solid objects from entering the drain pipe or drainage tube to prevent a blockage from forming, that can easily and quickly be removed by authorized personnel should it be necessary to clean the strainer, the sink or drain well, or have access to the drain pipe, and that once cleaned can be again easily and quickly installed.

OBJECTS AND SUMMARY OF THE INVENTION

Therefore, one object of this invention is to provide a strainer that can be operatively used with a floor drain or indirect waste receptor, such as a floor sink, so as not to protrude above the floor surface.

Another object of this invention is to provide a floor drain or indirect waste receptor, such as a floor sink, with a strainer that can be quickly and easily installed to form a sealing arrangement with the floor or sink discharge tube or with the drain pipe of the building drain system.

A still other object of this invention is to provide a floor sink strainer that will effectively block solid objects that enter the floor drain or floor sink well from entering the drain pipe and create a blockage in the building drain system.

A still further object of this invention is to provide a strainer that can be removed easily and quickly by authorized personnel should it be necessary to clean the sink well or the strainer or have access to the discharge pipe, and that can then be easily and quickly re-installed.

It is still another object of this invention to provide a strainer that is not easily and quickly removed without special equipment.

Other objects and advantages of this invention shall become apparent from the ensuing descriptions of the invention.

Accordingly, the strainer assembly of this invention comprises an expandable gasket member having a body sized to fit into a indirect waste receptor or floor drain discharge tube, or into a drain pipe of the building drain system, and having a lip section extending from the upper perimeter section of the body to seat above the top of the discharge tube or the drain pipe. The expandable gasket member further having a threaded passageway extending vertically through the gasket member. The strainer assembly further comprises a relatively rigid support structure whose exterior side walls are threaded to operatively mate with the threaded passageway of the gasket member. The support structure is sufficiently rigid and sized so that when it is operatively threaded to the gasket member it will expand the gasket member to form a seal with the interior surface of the discharge tube or the drain pipe. The rigid support structure also has an axially centered passageway to permit liquid and small particle material to pass into the drain pipe. The rigid support structure further has at least one spoke member extending between the side walls of the axially centered passageway and whose center section is provided with a vertically oriented opening extending through the at least one spoke member. The strainer assembly further comprises a top central oriented section provided with a screw opening extending through the dome-shaped strainer member that can be aligned with the opening in the center section of the spoke member. The strainer assembly also includes an elongated screw having a head section and a threaded section. The head section is sized to permit the head section to seat on the top central oriented section when the screw is inserted into the screw opening. The screw is sized to extend from the screw opening and into the opening in the center section of the spoke member to operative affix the strainer member to the rigid support structure.

In a preferred embodiment the rigid support structure will have more than one spoke member that together serve as a secondary strainer in the event that the strainer member is removed to prevent larger solid objects from entering the discharge pipe.

In another preferred embodiment the screw head will have a tamper resistant construction that permits only specialized tools to be used to disconnect the screw from the rigid support structure. In a more preferred embodiment the screw will be constructed to have a locking mechanism to further prevent an unauthorized person from disconnecting the screw from the rigid support structure so that the strainer member can be removed from the sink well.

When used with a floor sink it is preferred that the strainer will be dome-shaped having a first series of upper vertical slots and a second series of lower notches to facilitate the flow of liquid waste and smaller material through the strainer.

If the strainer is utilized with a floor drain having a sufficiently deep well, it is preferred that two strainers be utilized. One of the strainers would be a floor level strainer and the second strainer would be a dome-shaped strainer that fits within the well. In this embodiment the dome-shaped strainer would have a first series of upper vertical slots and a second series of lower notches to facilitate the flow of liquid waste and smaller material through the dome-shaped strainer. Additionally, the dome-shaped strainer would be constructed to have a top surface screw opening. In an alternate configuration the floor level strainer would also have a top surface screw opening alignable with the dome-shaped strainer screw opening. In these configurations the screw would seat over one of the two openings and extend sufficient distance into the opening in the center section of the spoke member to operative affix the strainer member to the rigid support structure.

PREFERRED EMBODIMENTS OF THE INVENTION

Without any intent to limit the scope of this invention, reference is made to the figures in describing the preferred embodiments of the invention.

There are various configurations of standard floor sinks and floor drains. Generally, each has in common a collection basin or well and a lower waste discharge tube extending downward from the floor of the collection basin. The discharge tube will be operatively connected to a drain pipe forming part of the building drain system so that liquid waste material entering the collection basin will pass into the drain pipe. In most cases the floor sink will not be positioned in a walking area of the floor but will be position underneath plumbing equipment so that the drain hoses from the plumbing equipment will be positioned over the floor sink. In this position the floor sinks would not a floor level strainer, but could have one if desired. On the other hand, in most instances the floor drain will be positioned in the walking areas of the floor and will therefore have a floor level strainer.

FIGS. 1A and 1Billustrate preferred constructions of the floor sink strainer assembly1that can be used to retrofit conventional style floor sinks2. InFIG. 1Athe strainer assembly1includes expandable gasket member5extends into and can form a seal with floor sink drainage tube4. InFIG. 1Bthe expandable gasket member5extends into and can form a seal with drain pipe4A. The description below discussing the features of theFIG. 1Aembodiment are equally appropriate for theFIG. 1Bembodiment except that expandable gasket member5extends into and can form a seal with drain pipe4A when support structure6is screwed into expandable gasket member5. In this embodiment a plumbing sealing material4B is utilized to attach drain pipe4A to drainage tube4.FIG. 1Cillustrates an alternate construction of a specially designed floor sink2wherein the floor sink drainage tube4is provided with interior threading4D that would permit the support member6to be directly attached to drainage tube4. In this alternate construction the need for an expandable gasket member would be eliminated.FIGS. 1D and 1Eillustrate embodiments of a floor drain2A. InFIG. 1Da floor level strainer30extends over the top of well3A and a dome-shaped strainer7is positioned within well3A and affixed by a tamper resistant screw8to a support structure6that is screwed into gasket5in the same manner as described with respect to the floor sinks2. InFIG. 1Ethere is no dome-shaped strainer7and tamper resistant screw8affixes the floor level strainer to the support structure6.

Referring toFIG. 1Athe floor sink strainer assembly1is constructed to fit within floor sink well3. In this configuration drainage tube4is operatively affixed by conventional means, such as coupling4E, to the drain pipe4A of the building drain system. Strainer assembly1comprises in a preferred embodiment an expandable gasket member5, a support structure6, a dome-shaped strainer member7, and an elongated tamper resistant screw8attachable to one another and within floor sink2as illustrated inFIG. 1A.

The expandable gasket member5is sized and shaped whereby it can be inserted into the discharge tube4. As seen inFIGS. 2 and 3, the expandable gasket member5has a body9constructed of an elastic rubber or plastic material or other similar material that can be expanded, but will return to its original shape when the expansion force is removed. Body9will be formed by a lip10extending horizontally outward from a vertical circular wall11having a smooth outer surface12and a threaded inner surface13that slopes inwardly from lip10to the bottom edge14of body9. When body9is positioned in discharge tube4, its outer surface12is positioned substantially parallel to and adjacent the discharge pipe inner wall surface15. The fit between outer surface12and inner wall surface15should be such that gasket member5can be manually pushed in and pulled out of discharge tube4, but which permits the two surfaces12and15to sufficiently frictionally engage one another to form a sealing relationship when body9is expanded by support structure6. In a preferred embodiment the sealing relationship will be such that gasket member5can not manually be pulled out of discharge tube4.

The support structure6shown inFIGS. 4 and 5is constructed of a relatively rigid plastic or similar material. Structure6includes a wall16sized and shaped whereby its threaded outer wall surface17will threadingly mate with threaded inner surface13in manner that causes gasket body9to expand into the desired sealing relationship described above. The threading action will also result in the support structure6and the gasket member5becoming affixed to one another whereby they can not manually be pulled apart. Support structure wall16forms a central passageway18that permits liquids and small solid particles to pass through the discharge tube4. There is at least one support spoke19extending between opposite sections20,21of wall16. In a preferred embodiment spoke19extends from the upper edge22to the lower edge23of wall16. Spoke19has a center section24provided with an attachment opening25. In a preferred embodiment opening25extends from the upper edge22to the lower edge23. To better permit support structure6to also function as a secondary strainer it is preferred that more than one spoke, such as spokes19A and19B, extend across opposite sections of wall16. This preferred structure decreases the size of the channels26-29formed by the multiple spokes19A and19B, and thus lessens the change that a solid large object may pass into the discharge tube4. In a more preferred embodiment there is a common center section24and attachment opening25for spokes19A and19B.

It is preferred that strainer member7have a raised shape, and more preferably a dome shape such as shown inFIG. 6, and preferably be constructed of a metal such as aluminum. This raised structure has durability and better permits fluids to flow through the strainer as materials build up in the floor sink well3. However, strainer member7could take other raised shapes, as well as be constructed from a rigid rubber or plastic. In an alternate embodiment a flat strainer or grate30could also extend over the well3to form a flat continuing surface to minimize the possibility that a person may trip over the well. It is preferred that strainer member7be sized to completely fit within well3. The dome shape wall31is provided with a first series of vertical slots32A that permit liquid and small solids to pass through wall31. In a more preferred embodiment there is a second series of vertical slots32B extending upward from the dome wall lower edge32C. The position and length of slots32B is set to maintain the structural stability of wall31. In a preferred embodiment slots32B will not extend above the lower section of slots32A and more preferably will be positioned below and between adjacent slots32A. The top center section33of wall31is provided with a screw opening34preferably formed by a round sloping wall edge35that forms a seat36for the head of a screw that may be inserted through opening34.

As illustrated inFIG. 7, the elongated tamper resistant screw8has a head37shaped to require a special tool for turning the screw8. One such shape would be a hex head that would require a nut driver for installing and removing the screw8from the strainer assembly. In another preferred embodiment the screw shank38can be provided with a groove39sized and shaped to accept a conventional locking device (not shown). In an alternate embodiment the screw shank38could incorporate a locking mechanism, such as a spring loaded latch, requiring a key to de-activate the lock. Other known locking mechanisms could be used.

To install the strainer assembly1into an existing floor sink2the sink well grate30is removed and the flexible gasket member body9is inserted into discharge tube4, preferably whereby lip10is seated above the discharge tube4. The support member6is then screwed into gasket member5to exert an expansion force against gasket member5to cause it to expand into sealing frictional contact with the inner surface15of discharge tube4. In an alternate embodiment, the support member6can be partially screwed into gasket member5and then gasket member5can be inserted into discharge tube4. This alternate embodiment provides a somewhat more rigid combination that in some instances may be easier to insert into discharge tube4. Once the two are inserted, then support member6is further screwed into gasket member5to cause a locking effect between the inner discharge wall15and the smooth outer surface12of gasket member5. With the support member6thus locked to gasket member5, and gasket member5in turn locked to discharge tube4, the dome-shaped strainer7is positioned over the discharge tube4and tamper resistant screw8is inserted through dome screw opening34. The dome-shaped strainer7is maneuvered in the floor sink well3to align opening34with attachment opening25so that screw8can be screwed using the necessary special tools into attachment opening25until the dome-shaped strainer7is tightened against the bottom wall40of floor sink well3.

In the event that it is desired to remove the strainer7, screw8can be removed again by using the necessary special tools (and key if a locking device is also utilized). Because special tools are required, it is less likely that unauthorized persons would remove strainer7. Even if that should occur, the construction of the support structure6acts as a secondary strainer, and this would also require its removal before any large solid object would be able to pass into the discharge pipe and create a blockage. If it is desired for the entire strainer assembly1to be removed, then with the dome-shaped strainer7removed one next unscrews the support structure6from the gasket member5at least sufficiently to remove the expansion force on the gasket member5and then pulls the support structure6and gasket member5from the discharge tube4. Alternatively, one can completely unscrew the support structure6from the gasket member5before pulling the gasket member6from the discharge tube4.

It has been found that if additional obstacles are placed on removing the strainers protecting the building drain system from blockage the less likely some unauthorized person will remove such strainers. Thus, this invention not only provides a strainer assembly1that is easy to install, but is difficult to remove without the correct tools. However, with the correct tools the strainer assembly1can be quickly and easily disassembled in part, or completely, for removal from the discharge tube4or as illustrated inFIG. 1Bfrom the drain pipe4A.