U.S. patent application number 12/492884 was filed with the patent office on 2009-10-22 for pet toilet.
Invention is credited to Hiroyuki Yamada, Jun YAMAMOTO.
Application Number | 20090260578 12/492884 |
Document ID | / |
Family ID | 36000085 |
Filed Date | 2009-10-22 |
United States Patent
Application |
20090260578 |
Kind Code |
A1 |
YAMAMOTO; Jun ; et
al. |
October 22, 2009 |
PET TOILET
Abstract
A pet toilet 10 having a toilet box 13, a drainboard 14
partitioning the toilet box into an upper compartment and a lower
compartment, an excreta treating material 15 laid in the upper
compartment, and an urine absorbent member 11 laid in the lower
compartment. The drainboard is an integral structure formed of a
plurality of longitudinally extending ribs 17 spaced parallel with
each other and a plurality of transversely extending ribs 18a and
18b intersecting the longitudinally extending ribs 17 and spaced
parallel with each other to have drain holes 12. Each drain hole 12
has a longitudinal dimension S2 at least twice its transverse
dimension S. The transversely extending ribs include ribs 18a with
a smaller height H1 from the drainboard surface 14a downward and
ribs 18b with a larger height H2 from the drainboard surface 14a
downward, the ribs 18a and the ribs 18b alternating with each
other.
Inventors: |
YAMAMOTO; Jun; (Tokyo,
JP) ; Yamada; Hiroyuki; (Tokyo, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
36000085 |
Appl. No.: |
12/492884 |
Filed: |
June 26, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11661788 |
Jun 1, 2007 |
7568448 |
|
|
PCT/JP2005/015879 |
Aug 31, 2005 |
|
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12492884 |
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Current U.S.
Class: |
119/166 |
Current CPC
Class: |
A01K 1/0114
20130101 |
Class at
Publication: |
119/166 |
International
Class: |
A01K 29/00 20060101
A01K029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 2, 2004 |
JP |
2004-256242 |
Oct 18, 2004 |
JP |
2004-303469 |
Claims
1. A pet toilet comprising a toilet box, a drainboard partitioning
the toilet box into an upper compartment and a lower compartment,
an excreta treating material laid in the upper compartment, and an
urine absorbent member laid in the lower compartment, the
drainboard being integrally constructed of a plurality of
longitudinally extending ribs spaced parallel with each other and a
plurality of transversely extending ribs intersecting the
longitudinally extending ribs and spaced parallel with each other
to have drain holes, each drain hole having a longitudinal
dimension at least twice the transverse dimension thereof, and the
height of the rib with the least height of all the ribs measured
from the surface of the drainboard downward being at least 0.8
times the transverse dimension of the drain hole.
2. The pet toilet according to claim 1, wherein the height of the
rib with the least height of all the ribs measured from the surface
of the drainboard downward being at least 0.8 times the transverse
dimension of the drain hole.
3. The pet toilet according to either of claims 1 or 2, wherein the
transverse dimension of the drain hole is 2 to 8 mm.
Description
[0001] This application is a Divisional of co-pending application
Ser. No. 11/661,788 filed on Jun. 1, 2007, and for which priority
is claimed under 35 U.S.C. .sctn. 120. application Ser. No.
11/661,788 is a 35 U.S.C. .sctn. 371 national phase application of
PCT International Application No. PCT/JP2005/015879 filed on Aug.
31, 2005. application Ser. No. 11/661,788 claims priority of
Application Nos. 2004-256242 and 2004-303469 filed in Japan on Sep.
2, 2004 and Oct. 18, 2004, respectively under 35 U.S.C. .sctn. 119,
the entire contents of all are hereby incorporated by reference
into the present application.
TECHNICAL FIELD
[0002] The present invention relates to a pet toilet and more
particularly a pet toilet having a toilet box partitioned by a
drainboard into an upper compartment and a lower compartment, with
a waste treating material laid in the upper compartment and an
urine absorbent member laid in the lower compartment.
BACKGROUND ART
[0003] Known pet toilets for treating the excreta of pets such as
cats and dogs include those disclosed in JP 7-67489A and JP
2003-180182A, in which a toilet box is partitioned into upper and
lower compartments by a porous member (drainboard), with an excreta
treating material put in the upper compartment and a urine
absorbent member made of an absorbent polymer, plant fiber, pulp,
etc. set in the lower compartment.
[0004] According to these pet toilet systems, liquid waste
discharged by a pet is allowed to quickly pass the excreta treating
material placed in the upper compartment, drop through the drain
holes of the drainboard, and be positively absorbed by an urine
absorbent member, such as a urine absorbing mat, laid in the lower
compartment of the toilet box. The urine absorbent member having
absorbed urine must be replaced periodically. For the purpose of
facilitating the replacement, JP Utility Model 61-22461A discloses
a system in which the lower compartment of the toilet box where the
urine absorbent member is placed is designed to be pulled out like
a drawer.
DISCLOSURE OF THE INVENTION
[0005] The present invention provides a pet toilet having a toilet
box, a drainboard partitioning the toilet box into an upper
compartment and a lower compartment, an excreta treating material
laid in the upper compartment, and an urine absorbent member laid
in the lower compartment. The drainboard is integrally constructed
of a plurality of longitudinally extending ribs spaced parallel
with each other and a plurality of transversely extending ribs
intersecting the longitudinally extending ribs and spaced parallel
with each other to have drain holes. Each drain hole has a
longitudinal dimension at least twice the transverse dimension
thereof. The height of the transversely extending rib measured from
the upper surface of the drainboard downward is different from that
of at least one of adjacent transversely extending ribs.
[0006] The present invention also provides a pet toilet having a
toilet box, a drainboard partitioning the toilet box into an upper
compartment and a lower compartment, an excreta treating material
laid in the upper compartment, and an urine absorbent member laid
in the lower compartment. The drainboard is integrally constructed
of a plurality of longitudinally extending ribs spaced parallel
with each other and a plurality of transversely extending ribs
intersecting the longitudinally extending ribs and spaced parallel
with each other to have drain holes. Each drain hole has a
longitudinal dimension at least twice the transverse dimension
thereof. The height of the rib with the least height of all the
ribs measured from the surface of the drainboard downward is at
least 0.8 times the transverse dimension of the drain hole.
[0007] The present invention also provides a pet toilet having a
toilet box, a drainboard partitioning the toilet box into an upper
compartment and a lower compartment, an excreta treating material
laid in the upper compartment, and an urine absorbent member laid
in the lower compartment. The lower compartment containing the
urine absorbent member has a drawer slidably removable in one
direction from the lower compartment. The drainboard is integrally
constructed of a plurality of longitudinally extending ribs
extending in a direction making an angle within 45.degree. with the
sliding direction of the drawer and spaced parallel with each other
and a plurality of transversely extending ribs intersecting the
longitudinally extending ribs and spaced parallel with each other.
The height of the longitudinally extending rib with the largest
height of all the longitudinally extending ribs measured from the
surface of the drainboard downward is larger than the height of any
transversely extending rib disposed within an area where the drawer
is movable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective of a pet toilet according to an
embodiment of the present invention, showing the way of setting a
urine absorbent member before scattering an excreta treating
material.
[0009] FIG. 2 is a perspective of a pet toilet according to an
embodiment of the present invention.
[0010] FIG. 3 is a perspective of a pet toilet according to an
embodiment of the present invention, showing the state before
scattering an excreta treating member.
[0011] FIG. 4(a) is an enlarged, fragmentary plan of a drainboard
of a pet toilet according to an embodiment of the present
invention.
[0012] FIG. 4(b) is a cross-section taken along line A-A in FIG.
4(a).
[0013] FIG. 5 schematically illustrates a method of measuring the
saturated water absorption of an urine absorbent member.
[0014] FIG. 6(a) is an enlarged, fragmentary plan of a drainboard
in a pet toilet according to another embodiment of the present
invention.
[0015] FIG. 6(b) is a cross-section taken along line A'-A' in FIG.
6(a).
[0016] FIG. 7(a) is a bottom plan view of a drainboard in a pet
toilet according to another embodiment of the present
invention.
[0017] FIG. 7(b) is an elevation view of a drainboard in a pet
toilet according to another embodiment of the present
invention.
[0018] FIG. 7(c) is a right-side view of a drainboard in a pet
toilet according to another embodiment of the present
invention.
[0019] FIG. 8(a) is a bottom plan view of another drainboard.
[0020] FIG. 8(b) is an elevation view of another drainboard.
[0021] FIG. 8(c) is a right-side view of another drainboard.
[0022] FIG. 9(a) is a bottom plan view of still another
drainboard.
[0023] FIG. 9(b) is an elevation view of the still another
drainboard.
[0024] FIG. 9(c) is a right-side view of the still another
drainboard.
[0025] FIG. 10 illustrates arrangement of longitudinally extending
ribs and transversely extending ribs in the drainboards of Examples
and Comparative Examples.
BEST MODE FOR CARRYING OUT THE INVENTION
[0026] The drainboard is a porous member having a large number of
drain holes which is an integral structure formed of a plurality of
longitudinally extending ribs spaced parallel to each other and a
plurality of transversely extending ribs spaced parallel to each
other and intersecting the longitudinally extending ribs. It is
desired that the drainboard make liquid waste having passed through
the excreta treating material drop into the lower compartment
without allowing the liquid to stay thereon so that the liquid may
effectively be prevented from being absorbed by the excreta
treating material or from staying on the drainboard to generate an
offensive odor. That is, it is desirable that the drainboard be
designed to effectively prevent urine having passed through the
excreta treating material from staying thereon while forming a film
of liquid bridging over the drain hole or attaching to the lower
side of the ribs.
[0027] The present inventors have found the following specific
design of the drainboard effective to avoid liquid waste from
forming a liquid bridge over the drain hole or attaching to the
lower side of the ribs and thereby staying there. The specific
design of the drainboard is that the drain holes defined by the
longitudinally extending ribs and the transversely extending ribs
are longer in their longitudinal direction than in their width
direction, and preferably have a longitudinal dimension at least
twice the transverse dimension thereof. The inventors have also
found it preferred that the above design be combined with an
additional feature that the height of the transversely extending
rib measured from the upper surface of the drainboard downward is
different from that of at least one of adjacent transversely
extending ribs and/or another additional feature that the height of
the rib with the least height of all the ribs measured from the
surface of the drainboard downward is at least 0.8 times the
transverse dimension of the drain hole.
[0028] The drainboard is generally made of resin or metal. The
drainboard tends to show plastic sagging due to the weight of the
excreta treating material put thereon and the body weight of a pet,
depending on the thickness and width of the ribs. If sagging occurs
in the case where the lower compartment of the toilet box has a
one-drawer structure, the irregularity on the lower side of the
drainboard tends to interfere with the sliding movement of the top
of the back wall of the tray, making it difficult to pull out the
drawer and causing problems in changing urea absorbent members.
[0029] To avoid such interference with the drawer's movement, if a
sufficient clearance is provided between the lower side of the
drainboard and the top of the back wall of the drawer, the upper
surface level of the drainboard should be so raised. As a result,
the toilet box will have an accordingly increased wall height,
which makes the toilet less easy for a pet to enter. Hence, it is
desired to effectively avoid the interference of the sag of the
drainboard with the back wall of the drawer while minimizing the
clearance between the lower side of the drainboard and the top of
the back wall of the drawer thereby to maintain the height of the
pet toilet. Then, the drawer will be pulled in and out smoothly to
achieve efficient replacement of the urine absorbent member with a
new one.
[0030] In a pet toilet system having a drainboard fabricated by the
intersection between longitudinally extending ribs and transversely
extending ribs and a drawer-like lower compartment containing a
urine absorbent member below the drainboard, the present inventors
have found that the following specific drainboard design is
effective to prevent interference of the sagged drainboard with the
top of the back wall of the drawer thereby allowing one to pull the
drawer in and out smoothly and to replace the urine absorbent
member easily. That is, the drainboard is designed to be an
integral structure constructed of a plurality of longitudinally
extending ribs spaced parallel with each other and extending in a
direction making an angle within 45.degree. with the moving
direction of the drawer and a plurality of transversely extending
ribs spaced parallel with each other and intersecting with the
longitudinally extending ribs. The drainboard is also designed such
that the height of the longitudinally extending rib with the
largest height of all the longitudinally extending ribs measured
from the surface of the drainboard downward is larger than the
height of any transversely extending ribs disposed within an area
where the drawer is movable.
[0031] As illustrated in FIGS. 1 and 2, a pet toilet 10 according
to a preferred embodiment of the present invention has an almost
rectangular open-top toilet box 13, a drainboard 14 as a porous
member partitioning the toilet box 13 into an upper compartment and
a lower compartment, and an almost rectangular, shallow tray 16
removably fitted under the drainboard 14. The upper compartment
provides a litter housing 21 above the drainboard 14, in which an
excreta treating material 15 in the form of numerous pellets is put
and laid. An absorbent mat 11 as a urine absorbent member is
removably disposed in the tray 16. The absorbent mat 11 is adapted
to absorb urine dropping from the litter housing 21 through the
drain holes 12 of the drainboard 14.
[0032] As described, the pet toilet 10 of the present embodiment
has the toilet box 13 partitioned by the drainboard 14 into an
upper compartment and a lower compartment, with the excreta
treating material 15 in the litter housing 21 of the upper
compartment, and the absorbent mat 11 in the tray 16 fitted into
the lower compartment. As illustrated in FIGS. 3, 4(a), and 4(b),
the drainboard 14 is an integral structure constructed of a
plurality of longitudinally extending ribs 17 substantially equally
spaced parallel with each other and a plurality of transversely
extending ribs 18a and 18b substantially equally spaced parallel
with each other. The longitudinally extending ribs 17 and the
transversely extending ribs 18a and 18b intersect with each other
to define drain holes 12. The longitudinal dimension of each drain
hole 12 is at least twice (10 times in this particular example
illustrated) its transverse dimension. The height of the
transversely extending ribs 18a, 18b measured from the upper
surface 14a of the drainboard 14 downward is different from that of
at least one of adjacent transversely extending ribs 18a, 18b (in
the present example illustrated, transversely extending ribs 18a
with a height H1 measured from the surface 14a downward and
transversely extending ribs 18b with a height H2 measured from the
surface 14a downward alternate with each other; the height H1 being
smaller than the height H2, the transversely extending ribs 18a and
18b will hereinafter be referred to as transversely extending,
first ribs 18a and transversely extending, second ribs 18b,
respectively). The term "longitudinal" or "longitudinally" as used
herein means "of or relating to the direction coinciding with the
longer side or a major axis of the drain hole 12 of the drainboard
14". The term "transverse" or "transversely" as used herein means
"of or relating to the direction coinciding with the shorter side
or a minor axis of the drain hole 12 of the drainboard 14".
[0033] The above-described drainboard design in the present
embodiment, in which the height of the transversely extending ribs
18a, 18b measured from the upper surface 14a of the drainboard 14
downward is different from that of at least one of adjacent
transversely extending ribs 18a, 18b, may be replaced with a
drainboard design in which the height H of the rib with the least
height of all the ribs 17, 18a, and 18b measured from the
drainboard surface downward is at least 0.8 times the transverse
dimension S1 of the drain hole 12 for the following reason. A film
of liquid (urine) bridging across a drain hole 12, a so-called
liquid bridge, is formed on the lower side of any of the ribs 17,
18a, and 18b that has the least height from the drainboard surface
14a downward. The excreta treating material 15 put on the
drainboard 14 must not drop through the drain holes 12. A spherical
excreta treating material 15, for example, must have a diameter
larger than the transverse dimension of the drain hole 12.
Accordingly, when the height of the rib with the least height of
all the ribs 17, 18a, and 18b fabricating the drainboard 14 as
measured from the drainboard surface 14a downward is at least 0.8
times the transverse dimension S1 of the drain hole 12, the excreta
treating material hardly comes into contact with the liquid bridge
and hardly absorbs urine.
[0034] In order to prevent urine from remaining on the drainboard
14 and to avoid the excreta treating material absorbing urine, it
is preferred not only that the height of the transversely extending
ribs 18a, 18b measured from the upper surface 14a of the drainboard
14 downward be different from that of at least one of adjacent
transversely extending ribs 18a, 18b, but also that the height of
the rib with the least height of all the ribs 17, 18a, and 18b
measured from the drainboard surface 14a downward be at least 0.8
times the transverse dimension S1 of the drain hole 12.
[0035] In the present embodiment, it is preferred that the
transverse dimension S1 of the drain hole 12 of the drainboard 14
be in the range of from 2 to 8 mm (3 mm in the example
illustrated).
[0036] The toilet box 13 is a molded article of a synthetic resin
such as polyethylene (PE), polypropylene (PP), an
acrylonitrile-butadiene-styrene copolymer (ABS). As in the example
shown in FIGS. 1 and 2, the toilet box 13 may have an almost
rounded-rectangular plan measuring, e.g., 200 to 800 mm in length
and 150 to 500 mm in width and have a height, e.g., of 100 to 200
mm. The toilet box 13 is partitioned into an upper compartment and
a lower compartment by a perforated partition 19 that is integrally
molded with the toilet box 13. The upper space measuring about 40
to 200 mm high from the drainboard provides an open-top litter
housing 21, while the lower space measuring about 0 to 40 mm deep
from the drainboard provides a tray housing 20 in which a tray 16
is removably fitted.
[0037] In the present embodiment, a pelletized, excreta treating
material 15 is put in the litter housing 21 constituting the upper
compartment of the toilet box 13. The excreta treating material 15
preferably has a water repellent function. For example, molded
products containing a ground material of plant origin and a
synthetic resin can be used. These molded products are poorly water
absorbent, preferably having a water absorption rate of 1% to 10%,
more preferably 1% to 5%. They allow discharged pet's urine to
swiftly pass therethrough, drop into the lower compartment through
the drain holes 12 of the drainboard 14, and be positively absorbed
by an absorbent mat 11 disposed in the tray 16 housed in the lower
compartment.
[0038] The term "absorption rate" as used herein denotes a weight
increase rate of a sample when soaked in water at 25.degree. C. for
3 seconds, being represented by the formula:
(Weight of sample after soaking-weight of sample before
soaking)/(weight of sample before soaking).times.100 (%)
[0039] In the present embodiment, the tray 16 is removably fitted
into the tray housing 20 in the lower compartment of the toilet box
13. The absorbent mat 11, which is a urine absorbent member, is
replaceably disposed in the tray 16 and thus set in the lower
compartment of the toilet box 13. The absorbent mat 11 can be a
plate molded from a molding material containing, e.g., plant fiber
or pulp or a clay mineral material. The absorbent mat 11 has a
thickness, e.g., of 2 to 20 mm and excellent water absorptivity as
represented by, for example, a saturated water absorption of 2 g/l
g or more. The absorbent mat 11 is thus adapted to efficiently
absorb urine having dropped from the upper compartment of the
toilet box 13.
[0040] The saturated water absorption is measured as follows.
<Method of Measuring Saturated Water Absorption>
[0041] A demand wettability tester shown in FIG. 5, which is well
known as an apparatus for carrying out a demand wettability test,
is used. A 60 mm wide and 60 mm long specimen is cut out of an
urine treating molding product with the thickness as molded, dried
in a dryer set at 105.degree. C. for 1 hour, and then allowed to
cool to room temperature in a desiccator. As illustrated in FIG. 5,
the thus conditioned specimen is put on the glass filter set on the
same level with the liquid level of physiological saline in the
burette. The three-way cock is opened to let the specimen absorb
physiological saline. When bubbling stops, the absorbing amount is
measured by reading the scale of the burette which indicates the
reduction of the liquid level of physiological saline, and the
amount is divided by the weight of the specimen to obtain the
amount of a saturated water absorption (g/g) (an average of three
specimens (n=3)). The measurement is made once on each one of three
specimens.
[0042] In the present embodiment, as illustrated in FIG. 3, the
drainboard 14 constitutes the main part of the partition 19, which
is integral with the toilet box 13, except the peripheral portion
19a. As illustrated in FIGS. 4(a) and 4(b), the drainboard 14 is
integrally formed of longitudinally extending ribs 17 parallel to
each other with a spacing S1, e.g., of 3 mm and transversely
extending ribs 18a and 18b parallel to each other with a spacing
S2, e.g., of 30 mm. The longitudinally extending ribs and the
transversely extending ribs intersect with each other at right
angles. Thus, the drainboard 14 has a great number of rectangular
drain holes 12 regularly arranged in a grid all over its area. The
drain holes 12 have a transverse dimension S1 of 3 mm and a
lengthwise dimension S2 of 30 mm.
[0043] In the present embodiment, each longitudinally extending rib
17 has a rectangular cross-section with, for example, a width of 2
to 10 mm and a height of 2 to 10 mm. Each transversely extending,
first rib 18a has a rectangular cross-section with, for example, a
width of 2 to 10 mm and a height of 2 to 10 mm. Each transversely
extending, second rib 18b has a rectangular cross-section with, for
example, a width of 2 to 10 mm and a height of 2.5 to 10.5 mm. All
the longitudinally extending ribs 17 and the transversely extending
ribs 18a and 18b are even on their upper surface to make the upper
surface 14a of the drainboard 14. Accordingly, the transversely
extending, first ribs 18a and the transversely extending, second
ribs 18b protrude downward with a smaller height H1 and a larger
height H2, respectively, from the surface 14a of the drainboard
14.
[0044] The drainboard 14 is preferably made of a synthetic resin,
such as polyethylene (PE), polypropylene (PP) or an
acrylonitrile-butadiene-styrene copolymer (ABS).
[0045] According to the present invention, each drain hole 12 of
the drainboard 14 formed of the ribs 18a, 18b, 17 should have a
dimension in the longitudinal direction at least twice as large as
that in the transverse direction. The dimension in the longitudinal
direction is preferably 3 to 15 times, more preferably 4 to 10
times, that in the transverse direction. As long as the
longitudinal dimension is twice or more the transverse dimension, a
liquid bridge of urine is drawn in the longitudinal direction by
capillarity and broken easily, leaving no urine on the drainboard
14.
[0046] The transverse dimension S1 of the drain hole 12 is
preferably 2 to 8 mm, more preferably 3 to 5 mm. Within that range,
the capillary force drawing the liquid bridge in the longitudinal
direction is strong to ensure an easy break of the liquid bridge,
leaving no urine on the drainboard 14.
[0047] The difference between the height H1 of the transversely
extending, first ribs 18a and the height H2 of the transversely
extending, second ribs 18b is preferably 0.5 to 6 mm, more
preferably 2 to 4 mm. When the difference between the height H1 of
the transversely extending, first ribs 18a and the height H2 of the
transversely extending, second ribs 18b is 0.5 to 6 mm, a liquid
bridge formed over the drain hole 12 will be destabilized by the
difference in level between the opposing ends thereof and broken
easily. Furthermore, the liquid (urine) of the broken liquid bridge
will easily gather to the transversely extending, second rib
18b.
[0048] The above-described constitution of the present embodiment
produces the following effect in the pet toilet 10 having the
toilet box 13 partitioned by the drainboard 14 into an upper
compartment and a lower compartment, the excreta treating material
15 laid in the upper compartment, and the absorbent mat 11 laid in
the lower compartment, the drainboard 14 having a large number of
oblong drain holes 12 formed by the intersection of longitudinally
extending ribs 17 and transversely extending ribs 18a and 18b.
Urine is prevented from forming a liquid bridge across the drain
hole or attaching the lower surface of the ribs 17, 18a and 18b.
That is, remaining of urine having passed through the excreta
treating material 15 on the drainboard 14 is avoided
effectively.
[0049] More specifically, according to the present embodiment, the
drain holes 12 of the drainboard 14 have a longitudinal dimension
at least twice as large as the transverse dimension. In addition,
the transversely extending, first ribs 18a with a smaller height
from the drainboard surface 14a downward and the transversely
extending, second ribs 18b with a larger height from the drainboard
surface 14a are alternately arranged. This configuration makes a
difference in level between the opposite ends of a liquid bridge
formed across a drain hole 12, which destabilizes the balance of
the liquid bridge. As a result, the liquid bridge formed over the
oblong drain hole 12 breaks easily and rapidly. At the same time,
urine attaching to the lower surface of the ribs 17, 18a, and 18b
is made to gather on the lower surface of the transversely
extending, second ribs 18b with a larger downward height and then
dropped smoothly. Thus, it is possible to effectively avoid the
excreta treating material 15 from absorbing the urine remaining on
the drainboard 14 and to prevent the remaining urine from
generating odor.
[0050] The present invention is not limited to the foregoing
embodiment, and various changes and modifications can be made
therein. The intersection between the longitudinally extending,
parallel ribs 17 and the transversely extending, parallel ribs 18
does not need to be at right angles. That is, the drainboard may be
formed by intersecting the ribs at angles deviating from
90.degree.. It is only necessary that the height of the
transversely extending rib measured from the upper surface of the
drainboard downward be different from that of at least one of
adjacent transversely extending ribs (one or two ribs out of
adjacent three is/are higher than the other(s)). All the
transversely extending ribs do not always have two different
heights and may have three or more different heights. Each drain
hole does not need to be an oblong rectangle and may have any
oblong shape such as an elongated circle. In the case of an
elongated circle, the major axis of the drain hole should be at
least twice the minor axis. The longitudinal direction of the drain
hole does not need to coincide with the longitudinal direction of
the toilet box and may be a direction oblique or orthogonal to the
longitudinal direction of the toilet box. The urine absorbent
member set in the lower compartment of the toilet box does not need
to be a plate-shaped mat that is laid in a tray. The adjacent
longitudinally extending ribs 17 do not need to be equal in height,
and as the transversely extending ribs, the height of the
longitudinally extending rib 17 may be different from that of at
least one of adjacent longitudinally extending ribs.
[0051] A second preferred embodiment of the present invention
provides a pet toilet 10' in which the almost rectangular, shallow
tray 16 removably fitted below the drainboard 14 in the
above-described first embodiment is a drawer slidable in the toilet
box 13. As illustrated in FIGS. 6(a) and 6(b), the drainboard 14 in
the second embodiment is an integral structure constructed of a
plurality of longitudinally extending ribs 17' substantially
equally spaced parallel with each other and a plurality of
transversely extending ribs 18' intersecting the longitudinally
extending ribs 17' and substantially equally spaced parallel with
each other. The longitudinally extending ribs 17' extend in a
direction making an angle within 45.degree. with the moving
direction X of the tray 16 as a drawer. In the particular example
illustrated, the extending direction of the longitudinally
extending ribs 17' coincides with the moving direction X. The
drainboard 14 is configured so that the height of the
longitudinally extending rib 17' with the largest height of all the
longitudinally extending ribs 17' measured from the surface 14a of
the drainboard 14 downward is larger than the height of any of the
transversely extending ribs 18' disposed within an area where the
drawer is movable. In the particular example illustrated, all the
transversely extending ribs 18' have the same height H2', all the
longitudinally extending ribs 17' have the same height H1', and the
height H1' is larger than the height H2'. In the second embodiment,
too, it is preferred that the height of the transversely extending
rib 18' measured from the drainboard surface 14a downward be
different from that of at least one of adjacent transversely
extending ribs 18' so as to effectively prevent urine having passed
trough the excreta treating material 15 from forming a liquid
bridge across the drain hole 12 of the drainboard 14 and thereby
from staying there or from attaching to the lower side of the ribs
17' and 18'. It is also preferred for the same reasons that the
height of the transversely extending rib 18' with the least height
of all the transversely extending ribs 18' measured from the
drainboard surface 14a downward is at least 0.8 times the
transverse dimension of the drain hole 12 of the drainboard 14. The
transverse dimension S1 of the drain hole 12 is preferably 2 to 8
mm, more preferably 3 to 5 mm. Within that range, the force drawing
a liquid bridge along the longitudinal direction is strong to
ensure an easy break of the liquid bridge, leaving no urine on the
drainboard 14.
[0052] The difference between the height of the longitudinally
extending ribs 17' and the height of the transversely extending
ribs 18' both measured from the surface 14a of the drainboard 14 is
preferably 0.1 to 10 mm, more preferably 0.3 to 5 mm, even more
preferably 0.5 to 2 mm, to ensure a smooth slide of the tray
16.
[0053] The term "moving direction X" as used herein means the
sliding direction of the tray 16 when pulled in and out of the
toilet box 13 as a drawer. The extending direction of the
longitudinally extending ribs should be 45.degree. or smaller from
the moving direction X, and is preferably 30.degree. or smaller
from the moving direction X. The transversely extending ribs 18'
intersect with the longitudinally extending ribs 17', making an
angle greater than 45.degree. with the moving direction X,
preferably an angle of 60.degree. or greater with the moving
direction X. The expression "area where the drawer is movable"
means the part of the drainboard 14 where the tray 16 horizontally
overlaps while pulling in and out when seen from above.
[0054] It is only necessary that at least one of the longitudinally
extending ribs 17' be designed to have a larger height than any of
the transversely extending ribs 18'. Other ribs 17' may have a
smaller height. FIGS. 8(a) to 8(c) can be referred to. In this
case, the longitudinally extending rib 17' with the greatest height
is preferably arranged as a longitudinally central rib 17a' in the
central portion of the drainboard 14 where the sag is greatest so
as to secure smooth movement of the tray 16. In the example
illustrated in FIGS. 8(a) through 8(c), some of the transversely
extending ribs 18' are higher downward than other ribs 18' to serve
as crosswise reinforcing ribs 18a'. Furthermore, as illustrated in
FIGS. 9(a) to 9(c), the drainboard 14 may have lengthwise
reinforcing ribs 17b', which have a larger height than the
transversely extending ribs 18' and are arranged within the recited
angle range, in addition to the longitudinally extending ribs 17'
defining the drain holes 12.
[0055] Irregularity on the lower side of the drainboard 14 due to
the transversely extending ribs 18' intersecting with the moving
direction X tends to interfere with the sliding movement of the top
of the back wall 16a of the tray 16. The second embodiment
providing the pet toilet 10' successfully avoids such interference,
helping a user slide the tray 16 smoothly and replace the absorbent
mat 11, a urine absorbent member, with ease. More specifically, as
shown in FIGS. 7(a) to 7(c), the drainboard 14 used in the pet
toilet 10' according to the second embodiment is an integral
structure constructed of a plurality of longitudinally extending
ribs 17' extending in the same direction as the moving direction X
of the tray 16 and spaced parallel with each other and a plurality
of transversely extending ribs 18' extending in a direction
intersecting the direction of the longitudinally extending ribs 17'
and spaced parallel with each other. The height of the
longitudinally extending rib 17' with the largest height H1' of all
the longitudinally extending ribs 17' measured from the surface 14a
of the drainboard 14 downward is larger than the height of any of
the transversely extending ribs 18' disposed within an area where
the tray 16 is movable. According to this configuration, while the
tray 16 is being pulled in and out in the tray housing 20 of the
toilet box 13, the top of the back wall 16a of the tray 16 comes
into contact with the longitudinally extending rib 17' with the
larger downward height H1' over the whole distance of the sliding
movement. A clearance is secured to avoid contact between the top
of the back wall 16a of the tray 16 and the transversely extending
ribs 18'. Therefore, the tray 16 can slide smoothly, with its back
wall 16a being successfully kept away from the interference by the
irregularity on the lower side of the drainboard 14 typically
caused by the transversely extending ribs.
[0056] The present invention is not limited to the aforementioned
second embodiment, and various changes and modifications can be
made therein. The extending direction of the longitudinally
extending ribs along the moving direction of the drawer does not
always need to coincide with the longitudinal direction of the
toilet box and may be oblique or orthogonal to the longitudinal
direction of the toilet box. The urine absorbent member set in the
lower compartment of the toilet box does not need to be a
plate-shaped mat that is laid in the tray.
EXAMPLES
[0057] The present invention will now be illustrated in greater
detail with reference to Examples and Comparative Examples, but it
should be understood that the invention is not limited thereto.
Example 1
[Making of Drainboard]
[0058] Drainboards, the specifications of which (i.e., drain hole
dimensions, height of longitudinally extending ribs, and heights of
transversely extending higher and lower ribs) is shown in Table 1,
were made. In the cases of using transversely extending ribs with
different heights (lower and higher), they were arrayed
alternately. Every rib had a width of 3 mm.
TABLE-US-00001 TABLE 1 Height of Longitudinally Extending Rib (mm)
2 4 6 8 Drain Hole Height of Transversely Extending Rib (mm)
(lower/higher) Dimensions (mm) 2/2 2/2.5 2/4 2/6 4/4 6/6 8/8 7.5/8
6/8 4/8 Trans- Longi- Difference in Height of Transversely
Extending Ribs (mm) verse tudinal 0 0.5 2 4 0 0 0 0.5 2 4 5 5
Incidence of Liquid Bridge (%) 89 78 61 62 90 87 94 72 50 6.0 Water
Absorption by Litter (g) 1.0 0.7 0.6 0.6 0.6 0.6 0.6 0.5 0.5 0.5
Water Adhesion to Drainboard (g) 0.4 0.3 0.1 0.1 0.6 0.5 0.6 0.4
0.4 0.1 Height of Liquid Bridge (mm) 1.8 -- 1.9 2.0 4.0 6.0 7.9 --
5.9 3.9 10 Incidence of Liquid Bridge (%) 67 53 40 0 66 62 60 53 20
0 Water Absorption by Litter (g) 0.8 0.6 0.6 0.4 0.6 0.5 0.6 0.3
0.3 0.3 Water Adhesion to Drainboard (g) 0.3 0.2 0.1 0.1 0.4 0.5
0.6 0.4 0.2 0.1 Height of Liquid Bridge (mm) 1.9 -- 2.0 2.0 4.1 5.9
7.9 -- 6.0 4.0 15 Incidence of Liquid Bridge (%) 57 40 23 0 54 49
40 27 3 0 Water Absorption by Litter(g) 0.7 0.4 0.5 0.3 0.5 0.6 0.6
0.4 0.4 0.3 Water Adsorption to Drainboard(g) 0.3 0.2 0.1 0.1 0.5
0.5 0.3 0.2 0.1 0.1 Height of Liquid Bridge (mm) 1.9 -- 2.0 2.0 4
5.9 7.9 -- 6.0 4.0 3 10 Incidence of Liquid Bridge (%) 93 77 53 43
91 88 80 67 37 17 Water Absorption by Litter (g) 0.9 0.5 0.5 0.4
0.5 0.5 0.5 0.3 0.4 0.3 Water Adhesion to Drainboard (g) 0.6 0.4
0.2 0.1 0.7 0.6 0.5 0.4 0.2 0.1 Height of Liquid Bridge (mm) 1.9 --
2.0 2.1 4 5.9 7.9 -- 6.0 3.8 15 Incidence of Liquid Bridge (%) 60
50 37 17 55 62 57 50 13 0 Water Absorption by Litter (g) 0.8 0.4
0.4 0.4 0.4 0.5 0.5 0.4 0.4 0.3 Water Adhesion to Drainboard (g)
0.5 0.3 0.1 0.1 0.5 0.6 0.6 0.3 0.1 0.1 Height of Liquid Bridge
(mm) 1.8 -- 1.9 2.1 4 5.9 7.9 -- 5.9 3.9 30 Incidence of Liquid
Bridge (mm) 33 7.0 0 0 39 41 40 10 3.0 0 Water Absorption by Litter
(g) 0.8 0.4 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Water Adhesion to
Drainboard (g) 0.4 0.3 0.1 0.1 0.4 0.4 0.5 0.3 0.1 0.1 Height of
Liquid Bridge (mm) 1.9 -- 2.0 2.0 4 5.9 7.8 -- 5.9 4.0
[Incidence of Liquid Bridge]
[0059] Each of the drainboards prepared was cut to a 150 mm side
square piece. The cut piece was immersed in a tank filled with an
ion exchanged water at 25.degree., pulled up at a speed of 10
mm/sec, and left to stand still for 5 seconds after taking out of
the water. The number of the drain holes over which a liquid bridge
was formed out of ten drain holes in the central part of the cut
piece was counted. The test was repeated ten times in total to
obtain an average incidence of liquid bridge formation.
[Height of Liquid Bridge]
[0060] In measuring the incidence of liquid bridge formation as
described above, the distance from the upper surface of the
drainboard to the liquid bridge was measured with a micrometer
caliper.
[Water Absorption by Litter and Water Adhesion to Drainboard]
[0061] A cylinder of 70 mm.times.70 mm in cross-section and 20 mm
in height was placed on each of the drainboards prepared, and about
70 g of litter as an excreta treating material was put into the
cylinder. Twenty grams of ion exchanged water at 25.degree. C. was
dropped into the cylinder at a rate of 1 g/sec. Five minutes after
completion of the dropping, the litter and the drainboard were
weighed to calculate the amount of water absorbed by the litter and
the amount of water adhered to the drainboard, respectively. As the
litter, commercially available woody pellets having a water
absorption rate of 4.3% (available from Kao Corp. under the trade
name "Nyantomo Seiketsu Toire Sarasarano Chippu"; diameter: 6.0 mm;
average length: 11 mm) were used.
[0062] As is seen from the results in Table 1, when in using a
drainboard having drain holes whose longitudinal dimension is twice
or more as long as the transverse dimension thereof and having a
difference in height between neighboring, transversely extending
ribs, the incidence of liquid bridge formation over the individual
drain holes is low, and adhesion of water to the drainboard is
small. In contrast, when either one of or both of these
configurational conditions is/are not fulfilled, the incidence of
liquid bridge formation over the drain holes is high, and adhesion
of water to the drainboard is large.
[0063] In the case where the height of the longitudinally extending
ribs of the drainboard is 0.8 or more times the transverse
dimension of the drain holes, water absorption by the litter can be
reduced even when water adheres to the drainboard and the incidence
of liquid bridge formation is high.
[0064] In the case where the longitudinal dimension of the drain
holes is twice or more times the transverse dimension of the drain
holes, the neighboring, transversely extending ribs are different
in height, and the height of the longitudinally extending ribs of
the drainboard is 0.8 or more times the transverse dimension of the
drain holes, both the water adhesion to the drainboard and the
water absorption by the litter are on low levels.
[0065] From these results, the pet toilet using a drainboard
satisfying the constitutional requirements of the present invention
proves effective in suppressing generation of odors from urine
because adhesion of urine to the drainboard can be reduced so that
the litter hardly absorbs urine.
Examples 2 and 3 and Comparative Examples 1 and 2
[0066] Drainboards having drain holes whose dimensions S1' and S2'
(see FIG. 6) were 3 mm and 30 mm, respectively, and having
longitudinally extending ribs and transversely extending ribs whose
heights are shown in Table 2 were made. The arrangement of the
longitudinally extending ribs and the transversely extending ribs
was as illustrated in FIG. 10. In the cases where longitudinally
extending ribs had two heights (longitudinally extending, lower
ribs (L) and longitudinally extending, higher ribs (T)), the height
of the lower ribs L was equal to that of transversely extending,
lower ribs (L). In the cases of using longitudinally extending,
lower and higher ribs and/or transversely extending, lower and
higher ribs, the lower ones and the higher ones were arrayed
alternately. All the ribs had a width of 3 mm.
Ease of Drawer Movement
[0067] An excreta treatment material (litter) of the amount shown
in Table 2 was put on each drainboard of Examples 2 and 3 and
Comparative Examples 1 and 2. The strain developed with time and
the force required to pull out the drawer were measured. The
results obtained are shown in Table 2.
TABLE-US-00002 TABLE 2 Comp. Comp. Exam- Exam- Exam- Exam- ple 1
ple 2 ple 2 ple 3 Drainboard Size (mm) Length 390 390 390 390 Width
290 290 290 290 Height of Transversely L 3 3 3 3 Extending Ribs
(mm) T 6 6 6 3 Height of Longitudinally L 3 3 3 3 Extending Ribs
(mm) T 3 6 6.1 6 Stress/Stain in Central Part 30.7 31.2 32.3 29.1
(N/10 mm) Clearance between Drainboard 5 5 5 5 and Drawer's Side
Wall (mm) Vertical Strain (litter: 2 Kg; 8.2 8.1 8.1 8.3 40.degree.
C.) (mm) Drawing Before Plastic 1.3 1.4 1.3 1.5 Force (N)
Deformation After Plastic 9.1 5.9 3.8 3.1 Deformation
[0068] It is seen from the results shown in Table 2 that, when the
downward height of the longitudinally extending ribs is larger than
the downward height of the transversely extending ribs by 0.1 mm or
more, the drawer is smoothly moved without needing so much force
even when the drainboard is largely deformed.
INDUSTRIAL APPLICABILITY
[0069] By use of the pet toilet system of the present invention, it
is possible to effectively prevent urine having passed through an
excreta treating material from staying on a drainboard having a
large number of drain holes, which are formed by the intersection
between longitudinally extending ribs and transversely extending
ribs, on account of urine bridge formation over the drain holes or
urine adhesion to the lower side of the ribs.
[0070] By use of the pet toilet system of the present invention
having a drainboard, which is formed by the intersection between
longitudinally extending ribs and transversely extending ribs, and
a drawer containing a urine absorbent member below the drainboard,
interference of the irregularity on the lower side of the
drainboard with the top of the wall of the drawer can effectively
be avoided. The drawer can thus be pulled in and out smoothly,
making it easy to replace the urine absorbent member.
* * * * *