Sink strainer assembly

Abstract

A sink strainer assembly for attachment to a clamping ring of a sink waste valve assembly comprising a strainer sized to fit within and be attachable to the clamping ring by a locking bar attachable to the clamping ring and at least one or more screws affixing the strainer to the locking bar, the improvement to which comprises (a) the strainer comprising a cylindrical body having top and bottom surfaces provided with passageways extending from the top surface and extending through the bottom surface to permit fluids to pass through the strainer, a channel cut in the bottom surface and having a post cavity of greater depth than the channel, a screw passageway extending from the bottom of the post cavity through the top surface of the strainer body; (b) the locking bar comprising an elongated slat member having a width greater than the depth of the channel and a length sized to fit in the channel, the slat having a post member sized to fit into the post cavity, the post member having an axial passageway formed by a threaded interior wall and positioned on the slat member to be aligned to the screw passageway when the locking bar is positioned in the channel, the slat having its opposing end sections forming a shoulder extendable beneath the clamping ring lower rim when the strainer is positioned in the clamping ring; and (c) a screw sized and shaped to fit into the screw passageway and be operatively engaged with the threaded interior wall of the post member.

Claims

1. A strainer assembly for use in a sink drain system having a drain assembly comprising a waste valve having a wall section containing internal threads configured to receive an externally threaded securing ring, the securing ring having walls that form a passageway, wherein the securing ring further comprises a ledge extending horizontally inward from the securing ring walls and into the passageway, the ledge having opposing access openings, the strainer assembly comprising: a) a strainer having a body sized to fit within the securing ring passageway and adjacent the walls of the securing ring, the body having a top surface and a bottom surface, the body having a plurality of drain passageways extending from the top surface to the bottom surface of the body, the body having at least one screw passageway extending from the top surface to the bottom surface; b) a securing member comprising an elongated member having a top surface and a bottom surface, the elongated member having at least one threaded opening positioned transverse to the top and bottom surface of the elongated member, the elongated member sized to pass through the access openings of the ledge when the elongated member is aligned with the access openings, the elongated member further sized to preclude passage of the ledge by the elongated member when the elongated member is not aligned with the access openings, whereby the elongated member may be passed through the ledge when aligned with the access openings and rotated to take the elongated member out of alignment with the access openings in the ledge; c) wherein the strainer body further comprises a channel on the bottom surface of the strainer body, the channel sized and configured to receive the elongated member and to align the at least one threaded opening of the elongated member with the at least one screw passageway of the strainer body when the elongated member is positioned in the channel; and d) at least one screw sized to pass through the at least one screw passageway and configured to engage the at least one threaded opening of the elongated member; whereby the securing member may be secured to the strainer by passing the screw through the at least one screw passageway and engaging the at least one threaded opening with the screw when the elongated member is positioned in the channel.

2. The strainer system according to claim 1 wherein the elongated member further comprises at least one post section having a vertical axis transverse to the top and bottom surfaces of the elongated member, wherein the at least one threaded opening of the elongated member is positioned within the post section along the vertical axis of the post section and wherein the channel is sized and configured to receive the post section and to align the post section with the at least one screw passageway in the strainer body.

3. The strainer system according to claim 2 wherein the post section is wider than the top surface of the elongated member.

4. The strainer system according to claim 1 wherein said plurality of drain passageways are of smaller surface area at the top surface than at the bottom surface.

5. The strainer system according to claim 4 wherein the plurality of drain passageways have a cross-section shaped to resemble a truncated inverted polygon with a wider base in the bottom surface and a narrower truncated top in the top surface.

6. The strainer system according to claim 5 wherein the plurality of drain passageways have individual cross-sections sized to permit fluids and solid particles having a diameter of less than ½ inch to flow through the passageways.

7. The strainer system according to claim 1 wherein the at least one screw passageway in the strainer body further comprises a screw head cavity positioned in the at least one screw passageway at the top surface of the strainer body.

8. The strainer system according to claim 7 wherein the at least one screw is a tamper resistant screw having a generally hex-shaped screw head opening; the screw head opening having a vertically extending guide member extending upward from the bottom of the screw head opening along the vertical axis of the opening.

9. The strainer system according to claim 8 wherein the at least one screw has a flat head and wherein the screw is sized to position the flat head level with the top surface of the strainer body when the flat head is fully seated in the screw head cavity.

10. The strainer system according to claim 1 wherein the body includes at least two screw passageways extending from the top surface to the bottom surface; wherein the elongated member includes at least two threaded openings positioned transverse to the top and bottom surface of the elongated member; wherein the channel is sized and configured to align each of the at least two threaded openings of the elongated member with one of the at least two screw passageways of the strainer body when the elongated member is positioned in the channel; and at least two screws, each sized to pass through one of the at least two screw passageways and configured to engage one of the at least two threaded openings of the elongated member.

11. The strainer system according to claim 10 wherein the elongated member further comprises at least two post sections each having a vertical axis transverse to the top and bottom surfaces of the elongated member, wherein one of the at least two threaded openings of the elongated member is positioned within each of the at least two post sections along the vertical axis of each post section and wherein the channel is sized and configured to receive the at least two post sections and to align each of the at least two post section with one of the at least two screw passageways in the strainer body.

12. The strainer system according to claim 11 wherein each of the at least two post sections are wider than the top surface of the elongated member.

13. The strainer system according to claim 11 wherein said plurality of drain passageways are of smaller surface area at the top surface than at the bottom surface.

14. The strainer system according to claim 13 wherein the plurality of drain passageways have a cross-section shaped to resemble a truncated inverted polygon with a wider base in the bottom surface and a narrower truncated top in the top surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings describe and/or illustrate the prior art and a preferred embodiment of this invention utilized with a commercial kitchen sink. However, it is to be understood that this embodiment is not intended to be exhaustive, nor limiting of the invention. It is but one example of the construction of this invention.

(2) FIG. 1 is an exploded view of a prior art strainer assembly that includes a thin metal disk-shaped strainer, an elongated flat plate and a bolt or screw construction used in conjunction with a commercial sink drain assembly including a conventional waste valve, securing ring, and gasket that affixes the waste valve to the floor surface of the sink basin when the securing ring is fully threaded into the throat area of the waste valve to form a seal between the waste valve upper rim and the sink basin floor lower surface and form a seal between the securing ring lip section and sink basin floor upper surface.

(3) FIG. 2 is an exploded view of a preferred embodiment of the strainer assembly of this invention comprising an improved strainer, improved securing member and improved tamper resistant screw construction

(4) FIG. 2A is a top view of the improved strainer illustrated in FIG. 2 showing the top openings of the multiple waste stream drainage passageways and the two top cavity screw passageways sized to receive and seat the heads of the tamper resistant securing screws illustrated in FIG. 2.

(5) FIG. 2B is a bottom view of the improved strainer of FIG. 2 illustrating a channel having two cavities at its opposite end sections sized to operatively receive the threaded securing posts of the FIG. 2 securing member.

(6) FIG. 2C is a side view of the improved strainer illustrated in FIG. 2

(7) FIG. 2D is a cross-sectional view taken along lines 2D-2D of FIG. 2A illustrating the preferred shape of the channel and screw passageways upper seating cavities.

(8) FIG. 2E is a cross-section view taken along lines 2E-2E in FIG. 2A illustrating the preferred shape of the drainage passageways.

(9) FIG. 3A is a three-quarter perspective view of the securing member illustrated in

(10) FIG. 2.

(11) FIG. 3B is a top view of the improved securing member illustrated in FIG. 3A.

(12) FIG. 3C is a bottom view of the improved securing bar illustrated in FIG. 3A.

(13) FIG. 3D is a side view of the improved securing bar illustrated in FIG. 3A.

(14) FIG. 4A is a top view of the tamper resistant screw illustrated in FIG. 2.

(15) FIG. 4B is a side view of the tamper resistant screw illustrated in FIG. 2.

(16) FIG. 4C is a cross-sectional view along lines 4C-4C of FIG. 4A illustrating the circular cross-section stub extending vertically upward from the center of the hex-shaped screw head opening for use to prevent conventional single blade or a Phillips shaped blade of a screwdriver from operatively being inserted into the screw head opening.

(17) FIG. 5A is a top view of an alternate embodiment of the strainer member utilizing only one screw.

(18) FIG. 5B is a bottom view of an alternate embodiment of the strainer member utilizing only one screw.

(19) FIG. 5C is a side view of an alternate embodiment of the strainer member utilizing only one screw.

(20) FIG. 5D is a cross-section view taken along lines 5D-5D of FIG. 5A

(21) FIG. 6A is a three quarter view of the restraining member when using only one screw.

(22) FIG. 6B is a bottom view of the restraining member illustrated in FIG. 6A.

(23) FIG. 6C is a top view of the restraining member illustrated in FIG. 6A.

(24) FIG. 6D is a side view of the restraining member illustrated in FIG. 6A.

(25) FIG. 6E is a three-quarter perspective view of an alternate structure of the strainer assembly security member that can be used with the invention.

(26) FIG. 7A is a top view of the securing ring illustrated in FIG. 2.

(27) FIG. 7B is a side view of the securing ring illustrated in FIG. 2.

(28) FIG. 7C is a bottom view of the securing ring illustrated in FIG. 2.

PREFERRED EMBODIMENTS OF THE INVENTION

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

(30) There are various configurations of standard commercial kitchen sinks. Generally, each sink has a basin formed by one or more walls and a floor provided with a drain opening. The cavity of the basin is often referred to as the well and is where plates, utensils, pots, pans and other cooking devices are rinsed. There will be a lower waste discharge assembly extending downward from drain opening in the sink floor. It is common that the assembly will include a waste valve between the drain opening and the lower waste discharge tube. The discharge tube will be operatively connected to a drain pipe forming part of the building drain system so that liquid waste material in the sink well will pass into the drain pipe.

(31) FIG. 1 is an exploded view illustrating a prior art sink drain assembly including the sink basin 1, a waste valve assembly 2 and a strainer assembly 3. The sink basin 1 typically has vertical walls 4 and a floor 5 having a top surface 6 and a bottom surface 7 forming a well 8. The well 8 is used to collect food and other waste particles rinsed off of dirty plates, pots and utensils. The floor 5 in the bottom area of the well 8 is provided with a drain opening 9 to permit the collected food and other small waste particles to be rinsed into the strainer assembly 3 and then passed to the waste valve assembly 2 and ultimately into the building discharge pipes (not shown) that lead generally to a sewer line. The primary function of the waste valve assembly 2 and the strainer assembly 3 is to prevent larger objects from be rinsed into the building drainage pipes which may cause a blockage and backup of the waste into the well 8.

(32) A conventional waste valve assembly 2 includes a waste valve 10 having known means (not shown) that can open, partially open or close the valve 10 to block the passage of material from the well 8 to the building drainage pipes. A typical waste valve 10 is constructed having body wall 16 having a threaded interior surface 17 forming the intake passageway or throat 18. The upper rim 20 of wall 16 is positioned beneath the drain opening 9 whereby food and other matter exiting drain opening 9 will be captured by the throat 18. The waste valve 10 is held in the desired position by a securing ring 11. As seen in FIGS. 1-2 and FIGS. 7A-7C, the securing ring 11 is tubular in shape having an upper lip 12 that will seat around the perimeter of the drain opening 9 when the securing ring 11 is inserted through the drain opening 9. The outer wall surface 13 of the securing ring 11 is threaded for the purpose of screwing the securing ring 11 into the threaded interior surface 17 of wall 16 forming the intake passageway or throat 18 of the waste valve 4. When the securing ring 11 is fully screwed into valve wall 16 the securing ring upper lip 10 forms a water tight seal with the top surface 6 of the basin floor 5. A gasket 21 is positioned on the waste valve upper rim 20 to ensure no leakage occurs between the waste valve upper rim 20 and the bottom surface 7 of the basin floor 5. Typically, the control means 19 to open and close the waste valve 10 is located underneath a cabinet and is not easily accessible. For that reason the waste valve 10 is generally fully opened to allow fast drainage from the well 8 and is rarely changed from that position except when necessary to prevent a backup from the sewerage and drain pipes into the sink well 8. As a result, with the waste valve 10 in an open position large particles and other materials can enter the waste valve 10 and are not blocked from entering the drainage pipes.

(33) The primary purpose of the strainer assembly 3 is to prevent the large particles and other materials from entering the waste valve 10 while still allowing an adequate flow of the rinse water and food particles to be discharged from the well 8.

(34) As shown in FIG. 1 one known strainer assembly 3 utilizes a flat, thin, metal disk 22 have multiple drainage openings 23 to permit the rinse water and small food particle to be discharged from the well 8 and into the waste valve throat 18. The disk 22 is sized and shaped to fit into the securing ring passageway 14. It is preferred that the disk 22 when positioned in the securing ring 11 be flush with the securing ring upper lip 12 so as not to damage plates and pans placed into the well 8, and to make certain fluid in the well 8 can flow out of well 8. To achieve the desire positioning of the disk 22, securing ring 11 is constructed having a ledge 29 protruding outward from the interior surface of wall 13 of the securing ring 11 at a known distance from its upper lip 12. Sections 24 of the disk surface are then punched to form “legs” 25 that are pushed downward and outward to contact the interior surface of wall 13 of the securing ring 11. The “legs” 25 are of sufficient length so when they contact the top surface 30 of securing ring ledge 29 the disk 22 will be at the same height as the securing ring upper lip 12. In order to maintain the position of the disk 22 during the flow of materials through the disk drainage openings 23, as well as when the disk 22 is struck by the pots and pans dropped into the well 8 it is necessary to secure the disk 22 to the securing ring 11. As illustrated in FIGS. 7A and 7C one known way to do so is to modify the ledge 29 to allow the use of a bar 26 that can be positioned under ledge 29. To get the metal bar 26 underneath ledge 29, ledge 29 is provided with two opposing gaps 32, 33 whereby the metal bar 26 can slip through the gaps 32, 33 to position the notches 26a and 26b in the opposing bar ends 26c and 26d, respectively, when rotated to be positioned above and below the metal bar 26. The bar 26 is thus blocked by the ledge 29 from being removed from its position. It is further necessary that opening 33 in the disk 22 be sized to allow a bolt 34 with threaded end 35 to pass through the center bolt opening 23 positioned in the center of metal disk 22 and extend downward to screw into a threaded opening 27 through the top surface 28 of the metal disk 26. As the bolt 34 is threaded into the metal bar 26 the metal bar 26 is forced into contact with the lower surface 31 of the ledge 29 and causes the disk 22 to become fixed in its position.

(35) Although the above strainer assembly can perform its function there are serious difficulties that the improved strainer assembly 3 of this invention solves. Those difficulties include, but are not limited to, maintaining the fixed position of the metal disk 22 when it or its “legs” 25 become bent, visual blockage by the disk 22 of the metal plate threaded opening 27 preventing or significantly increasing the difficulty in quickly threading the bolt 34 to the top threaded opening 27 in the metal bar 26, increased risk of dropping the metal bar 26 or bolt 34 into the waste valve 10, and ease of a person intentionally removing the disk 22 and removing the disk 22 without permission of the restaurant or facility owner.

(36) As seen in FIGS. 2, 2A-2D, in this invention the strainer assembly 3 comprises use of strainer body 36 having top and bottom flat surfaces 37, 38, respectively. As with the disk 22, the strainer body 36 is sized to fit within the securing ring 11. Preferably, strainer body 36 is approximately 0.75 inches in height and 3.375 inches in diameter when used with a 3.5 inch conventional sink drain 9. The height and diameter dimensions can vary depending on the drain size and the shape and size of the securing ring 11. Strainer body 36 has multiple drainage passageways 41 to permit water, other fluids and/or small food and other particles to pass through the strainer body 36 and into the waste valve 10.

(37) Unexpectedly, as seen in FIG. 2E, it has been found that more efficient fluid flow through the strainer body 36 can be achieved if the area of the passageway opening at the top surface 37 is smaller than the area of the passageway opening at the bottom surface 38. A particularly preferred shape of drainage passageway 41 is similar to a truncated inverted tapered polygon with the wider base in the bottom surface 38 and the narrower truncated top in the top surface 37. The number and size of the drainage passageways 41 is set to allow constant fluid flow through the strainer body 36 with little or no fluid backup in the sink well 8. It has been found this can be achieved if the area of the top surface of the drainage passageways 41 should be at least 30% of the total area of top surface 37.

(38) If the strainer body 36 is also provided with one or more screw passageways 42 sized to allow a tamper resistant screw 43 to be inserted into passageway 42 whereby it screw head 44 can be seated into the upper passageway cavity 46 shaped and sized to seat and accommodate all of screw head 44 so that screw head 44 will not extend above strainer body top surface 37.

(39) FIG. 6E illustrates an alternative structure for the strainer assembly securing member 50′ of this invention. In a preferred embodiment structure 50′ is a solid elongated bar 51′ having two threaded openings 56′ each positioned in the top surface 55′ of opposite end sections 53′ and 54′, respectively, of the bar 50′ whereby each opening 56′ will align with one of the screw passageways 42 of strainer body 36. The bar 50′ is constructed having a width less than the width of gaps 32 and 33, and a length that will extend under ledge 29 when bar 50′ is rotated by rotating strainer body 36.

(40) As seen in FIGS. 4A-4C it is further preferred that the screw head 44 have a flat top surface. To better prevent the screws 43 being intentionally removed and allowing the unauthorized removal of strainer body 36, it is still further preferred that a tamper resistant screw head 44 be used. It is most preferred that the screw head 44 have a 6 lobe or hex-shaped blade opening 47 further modified to have a pin or guide post 48 extending vertically upward from the center of blade opening 47 to block any non-conforming screwdriver blade from being used to remove screws 43.

(41) As seen in FIGS. 5A-5D if only one tamper resistant screw 43 is to be used, it is preferred that the screw passageway 42 be positioned along the central vertical axis “A-A” of the strainer body 36. As seen in FIGS. 2A-2B, and FIG. 2D, if two or more tamper resistant screws 43 are to be used, it is preferred that two of the screw passageways 42 be position along a vertical axis “B-B” and “C-C”, respectively, in the opposite end sections of a horizontal diameter line axis “D-D” of strainer body 36.

(42) As seen in FIGS. 3A-3D, the strainer assembly 3 also comprises a strainer securing member 50. The securing member of a conventional drainage system as shown in FIG. 1 can be used to operatively attach the metal plate 22 to the ledge 29. However, it is preferred that the novel strainer securing member 51 of this invention, seen in FIGS. 3A-3D (two screw configuration) or as seen in FIGS. 5A-5C and FIGS. 6A-6D or in FIG. 6E (one screw configuration), be used.

(43) In FIGS. 3A-3D strainer securing member 50 comprises a mid-section 51 having a post member 52 affixed at each opposing end sections 53, 54 of mid-section 51. Preferably, each post member 52 will be wider than the mid-section 51 and extend above the top surface 55 of the mid-section 51. Each post member 52 contains a threaded passageway 56 sized to operatively receive the threaded end 45 of corresponding screw 43. In a more preferred embodiment a metal cylinder 57 having a threaded interior wall 58 will be pressed or otherwise fixed in a non-threaded passageway 59 to provide additional stability and strength to the securing member 50. The securing member 50 also comprises shoulder members 60, 61 extending from the opposing ends of mid-sections 51/post members 52. The shoulder members 60,61 are sized to pass through ledge gaps 32,33 and pass under ledge 29 to contact ledge bottom surface 31 when the strainer assembly 3 is rotated to position the shoulder members 60,61 underneath ledge 29.

(44) As seen in FIGS. 5A-5B and FIGS. 6A-6D, if only one tamper resistant screw 43 is to be used, it is preferred that the strainer screw passageway 42 be positioned in the center vertical axis “A-A” of strainer body 36. Likewise, it would be preferred that the threaded interior wall 58 be positioned in the center vertical axis “A-A” of the mid-section 51 whereby the screw passageway 41 and the threaded interior wall 58 are in alignment.

(45) When the preferred securing assembly 3 is utilized, it is preferred that the bottom surface 38 of the strainer body 36 be provided with a channel 39 and post receiving cavities 40, preferable running along the diameter of the strainer body bottom surface 38 and in alignment with the post members 52. The channel 39 and its post receiving cavities 40 are sized and shaped to receive the securing member 50 so as to align the strainer body screw passageway 42 and the post threaded passageway 52 for easier insertion and threading of the tamper resistant screws 43, as well as easier engagement of the securing member 50 with the securing ring ledge 29.

(46) Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.