Disposable litter box

A pet animal excrement absorbing, disposable litter material container for placement of a supporting surface comprises a foldable side-wall structure without inherent leakage sealing characteristics and employs an impermeable membranous sheet as a barrier seal as well as for disposal of excrement and contaminated litter material. A rectangularly erect assembled state is maintained through balanced folding moment forces at each corner or by folding stiffening panels having squared ends which fit inside of adjacent side-wall sections. The components all fold to make a flat package for commercial distribution.

TECHNICAL FIELD 
The present invention relates to the field of collapsable litter containers 
for pets, in a form specifically adapted to be packaged for distribution 
and marketing, wherein an impermeable membranous sheet both protects 
against leakage and serves as packaging for disposal of contamination. 
BACKGROUND AND SUMMARY OF THE INVENTION 
Owners of small pets commonly provide indoor litter boxes to receive and 
hold animal excrement for later disposal. These litter boxes are most 
frequently used for cats, but are suitable for any domestic animal which, 
by natural inclination or training, is amenable to the discipline of 
voiding in a designated area. A container of suitable size made of 
plastic, metal or cardboard, and having a surrounding side-wall, is kept 
in a chosen location suited to the household. It is filled to a depth of 
2" or "3" with a cellulose or absorbant clay material, or with a 
commercial litter material which includes a deodorizing agent. The 
side-wall should be high enough to keep the litter in the container during 
any pawing and scratching that goes with its use. 
The litter material is rearranged periodically and those faces which can be 
picked up with a small scoop are removed for disposal. After a few days, 
perhaps a week, the litter material becomes saturated, or its deodorizing 
agent becomes ineffective, so that it must be disposed of and replaced 
with fresh material. This duty is probably the most distasteful part of 
pet care for an owner. Moreover, there are known health hazards such as 
toxoplasmosis, in handling of such wastes, most particularly for pregnant 
women. A reusable litter box adds to these onerous duties, since it too 
must be periodically cleaned. Newspaper is frequently used as a lining 
material, and to also serve as a protective floor cover under and around 
the litter box. When the same location is used for years, as is often the 
case, damage caused by leakage underlines the need for more positive 
protective covering. 
Small pets, and especially cats, are wonderful traveling companions except 
for the awkard logistics of the litter box. Also, the overt indelicacy of 
greeting one's host with a lovely pet on one arm and a litter box under 
the other is discomfitting at best. 
Thus, there is a long recognized need for a fully sanitary, disposable and 
transportable litter box for pets. It follows logically that such a litter 
box is potentially popular and profitable if proper cost and distribution 
dynamics are in place. To achieve good sales volume, this sort of product 
must be inexpensive and packaged for market distribution. U.S. Pat. No. 
3,626,900 discloses a flexible sheet with a peripherial drawstring. This 
sheet is laid on a flat surface to receive excrement, and the drawstring 
then facilitates its sanitary disposal, but the use of any litter 
material, or a means for its confinement are not disclosed. Some of the 
desired features are also disclosed in U.S. Pat. No. 4,913,091, wherein an 
assembly of parts provides a relatively inexpensive and light weight 
litter box. The vital aspect of commercial packaging for sales and 
distribution is not contemplated, even in this recent effort. 
A first object of the invention is therefor, to provide an economical, 
disposable alternative, thereby eliminating the unpleasant maintenance of 
a reusable litter box. Another object is to provide an impermeable 
protective cover for the floor under and around this disposable litter box 
as well as a sanitary enclosure for the disposal of the waste. A further 
object is to make this litter box in a compact, flat packageable form for 
both commercial distribution and use while traveling, without any 
sacrifice of functional strength or rigidity. 
The availability of an inexpensive device meeting these objectives can 
alter the present usage pattern by making it practical to use only a 
shallow layer of litter material and dispose of it each day or two. 
The present invention provides a litter box having rigid side-walls wherein 
the component parts fold into a compact form suitable for commercial 
packaging. A flexible sheet, which may have a peripheral drawstring, 
serves as an impermeable membranous seal and also as the disposal means. 
An arrangement of folding portions open to form the side-walls when 
erected. When unfolded in a rectangularly arranged, upright shape in the 
absence of an integral bottom panel, the side-walls are stiffened by 
folded stiffeners which lie flat against the supporting surface, and may 
extend either into or away from the interior of the rectangle. 
The flexible sheet, which may be in either flat or bag form, is fitted as a 
liner into the interior of the rectangle, and is drawn down around the 
exterior of the side-walls. If desired, an unsealed bottom reinforcing 
panel may be included under this impermeable membraneous sheet to maintain 
the rectangular shape, and a side support outer wall may be fitted over 
the erect side-walls to provide additional rigidity and to help hold the 
flexible sheet in place.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to FIG. 1 of the drawings, there is shown a litter box 
assembly 20, the first preferred embodiment of the present invention. The 
periphery of an impermeable membraneous sheet 60 is confined by 
continuous, foldable side support assembly 24. This sheet 60 is fitted 
inside of, and drawn down over, a continuous side-wall assembly 30, which 
is hidden in FIG. 1, but is clearly shown in FIG. 2. Fold lines 25f--25f 
extend across opposed longitudinal side-wall sections 25--25 of side 
support assembly 24, dividing each into two parallel folding panels 25a 
and 25b and in the same manner, fold lines 26f-28f extend across the 
opposed transverse side-wall section 26 and 28. Transverse side-wall 
section 26 and 28 differ only to the extent of the optional height 
reducing cut-out 29, allowing easier access by the pet. Side support 
assembly 24 is urged to assume and maintain a rectangular state by 
balancing the forces of folding moments across the four corners 23--23. 
The side support assembly 24 can be made from heavy corrugated box 
material so that it can carry heavy vertical edge loading, making it 
possible to use light weight material for the side-wall assembly 30. The 
side support assembly 24 also allows the use of a loosely fitted 
impermeable membranous sheet 60 by keeping any free folds neatly in place 
and also helps to maintain the rectangular shape of the erected litter box 
assembly 20. Clearly however, if side-wall assembly 30 is made from 
heavier material, and if impermeable membraneous sheet 60 is more closely 
fitted, side support assembly 24 is not needed. The optional height 
reducing cut-outs 29 and 37 permit greater side-wall assembly height for 
better confinement of litter material. FIG. 2 shows the foldable, 
continuous side-wall assembly 30 in the unfolded and rectangularly erect 
state and further shows that said assembly is not inherently impermeable 
to leakage. The fold lines 32f--32f extend from side-wall upper limit 40, 
across opposed longitudinal sides 32--32, dividing each into two panels, 
32a and 32b through side-wall lower limit 42 and across stiffeners 33--33. 
In the same manner, fold lines 36f-38f extend across the opposed 
transverse sides 36 and 38, dividing each into two panels, through 
side-wall lower limit 42, and across stiffeners 35--35. Transverse sides 
36 and 38 differ only to the extent of the height reducing cut-out 37. 
In the absence of an integral, sealed bottom panel, the open, unfolded 
condition of sides 32, 36 and 38 is enforced by the angular relationship 
of stiffeners 33--33 and 35--35 respectively, which are folded toward the 
interior of side-wall assembly 30. Side-wall assembly 30 is urged to 
assume and maintain a rectangular state through balancing of the folding 
forces across the four corners 31--31. Moreover, the square-cut ends 33a 
of stiffener 33, or 35a of 35, depending upon folding sequence, will bear 
against the inner surfaces of side-wall assembly 30 so as to also maintain 
the rectangular state. 
Referring to FIG. 3, there is shown a similar side-wall assembly 30', 
differing from side-wall assembly 30 only to the extent that stiffeners 
33'--33' and 35'--35' are extended to more or less completely cover, but 
still not seal, the bottom area 50. FIG. 4 shows an alternate form of the 
unfolded and rectangularly erect state of side-wall assembly 30, differing 
from FIG. 2 only in that stiffeners 33--33 and 35--35 are now folded 
outwardly. 
FIGS. 5, 6 and show alternate forms of the foldable impermeable sheet means 
60 of FIG. 1. The bag 60a of FIG. 5, made from 0.002" to 0.004" thick high 
density polyethylene film is a preferred form. Although other materials 
may be used, the polyethylene is favored for reasons of availability, cost 
and ease of manufacture. The bag 60a is of a rectangular shape having 
longitudinal dimension 61 and transverse dimension 62, conforming to the 
dimensions of side-wall assembly 30, and a height 63 for fitting with 
side-wall assembly 30 as shown in FIG. 1. A drawstring 64 runs through the 
hem 65 for closure and disposal of the bag 60a. The plastic bag 60b, as 
shown in FIG. 6 differs from bag 60a only in the omission of drawstring 64 
and hem 65, and is gathered and closed by a twisted tie 66. The foldable 
impermeable sheet 60 need not take a bag-like form but, may be a flat 
plastic sheet 60c as is shown in FIG. 7. There is shown a plastic sheet 
67, made of the preferred high density polyethylene and again, other 
materials are suitable. Hem 68 borders sheet 67, confining drawstring 69, 
so that the periphery there of sheet 67 may be gathered and held together 
for waste disposal. 
In commercial distribution, packaging of the invention in a minimal volume 
reduces shipping cost as well as the risk of in-transit damage and 
facilitates shelf display, all highly desirable attributes. In order to 
achieve this end each component must fold into a flattened shape as is 
shown in FIGS. 8, 9 and 14. 
FIG. 8 shows the side-wall assembly 30 folded at diagonally opposite 
corners 31--31 to achieve flattened shape 44 without folding of 
longitudinal sides 32--32 or transverse sides 36 and 38. Side support 24 
is folded in a similar manner, to flattened shape 46. It should be noted 
that, in order to produce the balance of folding moment forces desired to 
urge and maintain the rectangular shape as mentioned previously, the 
folded corners 23 and 31 should be staggered when the assembly of FIG. 8 
is erected. A useful multiple set of plastic bags 60a are folded and 
stacked in flattened shape 48 and these shapes 44, 46 and 48 are then 
ready for packaging together in a carton, or in "shrink wrap" plastic, as 
is widely practiced. A package of reduced overall dimensions can be 
readily made, if so desired, by additionally folding the flattened shapes 
44 and 46 along fold lines 45 and 47 respectively. 
In FIG. 9 is shown the side-wall assembly 30 as an alternate flattened 
shape 52, made by folding transverse sides 36 and 38 along fold lines 36f 
and 38f, so as to also fold inwardly at corners 31--31. Side support 24 is 
folded in a similar manner to flattened shape 54, and multiple sets of 
plastic bags 60a are folded and stacked in flattened shapes 56--56. These 
flattened shapes 52, 54 and 56--56 are then ready for final packaging in 
the above described manner. 
Referring now to FIG. 10, a second litter box assembly 90 is shown in an 
exploded view as a second preferred embodiment of the invention. Here, the 
side support assembly 24 may be the same as used for the first litter box 
assembly 20, and the same foldable plastic bag 60a may be used. The 
foldable flat plastic sheet 60c is shown in this instance to demonstrate 
its application. A second side-wall assembly 80 is shown, with upper limit 
84 and lower limit 86 but without an equivalent of the stiffeners 33 or 35 
of side-wall assembly 30. The foldable flat sheet 60c is arranged to fit 
closely inside of, over and around side-wall assembly 80 by making the 
bias folds 70, and side support assembly 24 holds these folds 70 in place. 
Bottom 74 comprises foldable bottom section 75 with opposed stiffeners 
76--76 which fold upwardly along fold lines 71--71, to stiffen foldable 
bottom section 75 along fold line 76f. The stiffeners 76--76 fit closely 
inside of side-wall assembly 80 so as to retain said folded relationship 
to bottom section 75 and to also urge and maintain rectangularity of 
side-wall assembly 80. The lower limit 86 of Side-wall assembly 80 rests 
on extended edges 77--77 of bottom section 75 so as to prevent folding 
thereof along fold line 75f. 
FIG. 11 and 12 illustrate how the flattened shape 52 of FIG. 9 may be 
further reduced in overall dimension by an additional fold along fold 
lines 32f--32f giving the flattened shape 92 of FIG. 12. FIG. 13 shows the 
manner of folding bottom 74 of FIG. 10, into a flat shape 95 for 
packaging. 
FIG. 14 shows the compact flattened shape 92, a side support assembly 24 
similarly folded to comprise similar shape 94, and a multiple set of bags 
60a--60a are arranged for packaging together in a carton, or in "shrink 
wrap" plastic as previously described. 
In FIG. 15 is shown an alternate embodiment of a side support assembly 100 
which may be used interchangeably with side support 24. Side support 
assembly 100 includes upper panels 102 and 103, with panel 102 shown in 
the erect state as when assembled for use, and panel 103 shown folded 
along upper fold line 103f as for flat packaging. Handles 104--104, 
provided by cut-outs in panels 102 and 103, are elevated in the erect 
position so as to facilitate placing and removing side support assembly 
for maintenance. Flat packaging is accomplished in a manner similar to 
that shown in FIG. 9, by folding sides 106--106 inwardly along fold lines 
106f--106f and alsofolding upper panel 102 along fold line 102f as 103 is 
shown to be. 
It will be understood that the invention is not limited to the disclosed 
embodiments, but is capable of rearrangement, modification and 
substitution of parts and elements without departing from the spirit of 
the invention.