Sink strainer for garbage disposal unit

A sink strainer for a garbage disposal unit includes a strainer unit, a seat and a mounting flange. The strainer unit includes a handle, a strainer member and a plug member. The plug member has a platform and a surrounding wall depending from the platform on which multiple slope guide are located. The seat includes a limiter located at a lower portion of the seat, a stopping surface protruding from and surrounding a middle portion of the seat, a snapping portion at a top of the seat, and another snapping portion at a bottom of the seat. The mounting flange is provided at a top end with a flange portion and at a bottom end with a mounting portion. The sink strainer may further include a decorative flange having a flange portion and a snapping portion which are dimensioned and configured to abut on, and be engaged with, the flange portion and top snapping portion of the seat.

FIELD OF THE INVENTION 
The present invention relates to a sink strainer for garbage disposal unit, 
and particularly to a sink strainer comprising a strainer unit, a seat and 
a mounting flange, and still particularly to a sink strainer further 
comprising a decorative flange. 
BACKGROUND OF THE INVENTION 
Conventionally, sink strainers for garbage disposal unit are various in 
structure. A sink usually has two straining holes one for mounting with a 
garbage disposal unit, and the other for drainage only, wherein the former 
hole needs a plug as a stopper and the latter uses a strainer. However, 
using the plug still encounters setbacks such as when pulling off the 
plug, spoons or forks will drop into the garbage disposal unit causing 
damage thereto. Therefore, stoppers having also a function of strainer 
were developed. One of the examples may be found in U.S. Pat. No. 
5,265,281 which discloses a stopper for garbage disposal unit inlets. The 
prior stopper comprises a side wall defining a bore and carrying an 
external sealing member for releasably engaging the inner face of the bore 
of an existing sink flange, an upper flange extending radially outwardly 
from an upper end of the side wall for covering the upper face of the 
existing sink flange, a strainer member extending across the bore and a 
lower wall extending across the bore below the strainer member and 
including a plug member movable between a sealing position and an open 
position in which fluid may drain through the stopper. A plug operating 
member extends upwardly from the plug member and through the strainer 
member to allow the plug member to be lifted to the open position. 
In this prior art, it is necessary to take the whole unit out in order to 
introduce garbage into the disposal unit. Obviously, such operation is 
inconvenient. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a sink strainer for 
garbage disposal unit, comprising a strainer unit, a seat and a mounting 
flange, where the strainer unit can be taken out easily by simply turning 
the strainer unit to disengage the slope guide and the limiter. 
Still another object of the present invention is to provide a sink strainer 
for garbage disposal unit, further comprising a decorative flange so that 
the user can readily select and mount to the stainer a decorative flange 
bearing a color may more fit the color of the sink or to meet the 
desireness of the user. 
Generally speaking, the sink strainer according to the present invention 
comprises a strainer unit, a seat and a mounting flange. The strainer unit 
includes a handle, a strainer member and a plug member. The handle has a 
foot. The strainer member has a plurality of openings spaced 
equi-distantly from one another around the strainer member, and a central 
hole. The plug member has a platform, a surrounding wall depending from 
the platform, on which multiple slope guides are located and are 
equi-distantly spaced from one another, and a stem upright from the center 
of the plug member. In assembling the strainer unit, the stem of the plug 
member passes through the central hole of the strainer member and is 
tightly engaged with the foot of the handle so that the handle, the 
strainer member and the plug member become one single strainer unit. The 
seat includes a limiter located at the lower portion of the seat, a 
stopping surface protruding from and surrounding the middle portion of the 
seat, a snapping portion at the top of the seat, and another snapping 
portion at the bottom of the seat. The mounting flange is provided at its 
top with a flange portion and at its bottom with a mounting portion. In 
assembly, the surrounding wall of the plug member is received to and abuts 
on the stopping surface, and the limiter inserts into one of the slope 
guides, so that when turning of the plug member the plug member will be 
forced to go up or down and for the latter case, the seal ring of the plug 
member will abut on the stopping surface resulting from a closed status, 
while turning of the plug member in a counter direction, the plug member 
will go up producing a gap between the seal ring of the plug member and 
the stopping surface of the seat and thus resulting from an opened status. 
Removing the strainer unit to introduce garbage into the disposal unit can 
be achieved by simply turning the strainer unit to disengage the slope 
guide and the limiter. The sink strainer may further comprises a 
decorative flange having a flange portion and a snapping portion, which 
are dimensioned and configured to abut on, and be engaged with, the flange 
portion of the mounting flange and the snapping portion of the seat. The 
decorative flange is readily selected and mounted into the strainer by 
having a color more conformed with the color of the sink to be 
incorporated therewith or more desirable to the user.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIGS. 1, 2 and 3, the sink strainer according to the present 
invention comprises a strainer unit 10, a seat 30 and a mounting flange 
40. The strainer unit 10 includes a handle 11, a strainer member 12 and a 
plug member 13. The handle 11, being of flat oval, has a foot 111 inside 
of which interior thread is provided. The strainer member 12, being of 
circular-basket shape, has a plurality of openings 121 spaced 
equi-distantly from one another around the strainer member 12, and a 
central hole 122. The plug member 13 has a platform 131 of circular 
flatness, a surrounding wall 138 depending from the platform 131, on which 
multiple slope guides 135 are located and are equi-distantly spaced from 
one another, and a stem 133 having exterior thread and upright from the 
center of the plug member 13. A seal ring 134 is provided underneath the 
platform 131 and surrounding the top of the surrounding wall 138. In the 
present embodiment of the invention, the number of the slope guides 135 
are three departing from one another in 120 degrees. The slope guide 135 
is provided with a protrusion 136 at its upper side. In assembling the 
strainer unit 10, the stem 133 passes through the central hole 122 and is 
screwingly engaged with the foot 111 so that the handle 11, the strainer 
member 12 and the plug member 13 become one single strainer unit 10. On 
the platform 131 a protruded plane 132 is provided with on which the 
strainer member 12 is seated. 
The seat 30 includes a protruded limiter 31 located at the lower portion of 
the seat 30, a stopping surface 33 protruding from and surrounding the 
middle portion of the seat 30, a snapping portion 32 formed at the top of 
the seat 30, and another snapping portion 36 at the bottom of the seat 30. 
A groove 35 is provided at the exterior of the seat 30 for receiving a 
seal ring 34. 
The mounting flange 40 is provided at its top with a flange portion 41 
adopted to be incorporated with a conventional sink, and at its bottom 
with a mounting portion 42. 
In assembly of the sink strainer according to the present invention, the 
surrounding wall 138 is received to and abuts on the stopping surface 33, 
and the limiter 31 inserts into one of the slope guides 135, so that when 
turning of the plug member 13 it will be force to go up or down and for 
the latter case, the seal ring 134 will abut on the stopping surface 33 
resulting from a closed status (as shown in FIG. 1), while turning of the 
plug member 13 in a counter direction, the plug member 13 will go up and 
the limiter 31 is then forced to go over the protrusion 136 and retarded 
thereby for maintaining in position, producing a gap between the seal ring 
134 and the stopping surface 33, and thus resulting from an opened status 
(as shown in FIG. 2) making drainage possible. Removing the strainer unit 
10 to introduce garbage into a conventional disposal unit 50 can be 
achieved by simply by turning the strainer unit 10 to disengage the slope 
guide 135 and the limiter 31. 
As shown in FIGS. 4 to 6, another embodiment of the present invention, the 
sink strainer may further comprises a decorative flange 20 having a flange 
portion 21 and a snapping portion 22, which are dimensioned and 
configurated to abut on, and be engaged with, the flange portion 41 and 
the snapping portion 32. The decorative flange 20 is readily selected and 
mounted into the strainer by having a color more conformed with the color 
of the sink to be incorporated therewith or more desirable to the user. 
In FIG. 7, the sink strainer according to the second embodiment of present 
invention is mounted to the conventional garbage disposable unit 50 by 
engaging it with the mounting portion 42 of the mounting flange 40. 
While particular embodiments of the present invention have been illustrated 
and described, it would be obvious to those skilled in the art that 
various other changes and modifications can be made without departing from 
the spirit and scope of the invention. It is therefore intended to cover 
in the appended claims all such changes and modifications that are within 
the scope of this invention.