Protective insert for a plastic trash bag

A foldable holder for flexible trash bags, the holder having planar sections which are connected to one another along adjacent edges so as to form a closed or tubular body. The preferred material for the planar sections or panels is corrugated paperboard (i.e., "cardboard"). The preferred configuration includes four connected panels which are sized to create a square-shaped holder when the panels are moved to their fully expanded condition. Two opposite panels are scored vertically along their mid-regions so that they may be folded internally until they touch--or nearly touch, thereby allowing the other two sides to be brought together in a parallel fashion. The collapsed mode for the holder (wherein the holder constitutes only about 5% of its expanded mode) constitutes a handy storage condition for the holder, so that it might be tucked behind an appliance such as a stove or hung in a closet when it is not in use. The sizes of the respective panels are designed so that the circumference of the expanded holder will be as large as the nominal circumference of the bag that is to be supported, but not more than about 2% greater than the nominal circumference of the bag, whereby a very slight stretching action may be required in order to install the holder inside a bag. A slightly stretched plastic bag will tend to hold the expanded holder in its full-open condition, such that no auxiliary clips, braces or frames are needed in order to maintain a holder open. The holder is self-supporting, so that it may be loaded in either its vertical or horizontal mode. When the bag is full, the top of the holder is grabbed and manually lifted out of the bag.

BACKGROUND OF THE INVENTION 
This invention relates generally to rigid supports and holders for flexible 
plastic bags of the kind that are not self-supporting and which are 
commonly used to receive and transport residential trash, leaves, brush 
and related matter that is to be discarded; more specifically, it relates 
to a device for preventing any discarded matter that has sharp corners or 
sharp points (such as rose brush clippings) from accidentally tearing the 
sides of such a plastic bag during the process of loading the discarded 
matter in the bag. 
It is known that large flexible bags, typically made of thin polyethylene, 
are especially handy for disposing of trash and waste matter which is to 
be discarded, especially including refuse from a yard--such as leaves, 
weeds, branches and thorns, grass clippings, etc. These bags are usually 
relatively large, often rated at 39 to 55 gallons; and many such bags are 
specifically sold for the purpose of accommodating lawn and yard refuse. 
These relatively large bags are often called "lawn and leaf" bags, 
although they probably differ from other plastic bags only in their total 
capacity and perhaps their wall thickness. 
In addition to "lawn and leaf" or similar bags intended for outdoor use, it 
is common to use polyethylene bags having a capacity of about 26 to 33 
gallons for handling household trash and garbage that tends to regularly 
materialize inside a residence, including discarded packing material, 
waste paper, junk mail, empty bottles and food scraps, etc. Such 
indoor-type or "garbage" bags are more commonly used within a house, of 
course, and they are less frequently exposed to the kind of sharp material 
which would be expected to cut or tear a bag. That is, if a household 
trash bag fails, it normally does so because its capacity was exceeded, 
i.e., too many heavy things were put into the bag, and the excess weight 
caused a seam or wall to part. But because there is no way to anticipate 
whether a consumer will use a 26-gallon plastic bag inside the house or in 
the yard, all such bags having a size that is large enough to make them 
practical for outdoor use will be considered to fall within the scope of 
this invention. For convenience, then, all plastic bags having a rated 
capacity of at least 26 gallons will be referred to herein as simply trash 
bags. 
It is known to use auxiliary holders for trash bags in order to support 
them during the time that trash is being accumulated therein. One such 
holder is disclosed in U.S. Pat. No. 4,037,778 to Boyle entitled 
"Universal Bag Support." Apart from the technical advantages or 
disadvantages of the Boyle structure, his disclosure makes a very good 
point when it suggests that plastic bag holders may advantageously be 
divided into two principal groups: those which support a bag from the 
outside and those which support it from the inside. The Boyle disclosure 
is also believed to be accurate when it describes many of the 
disadvantages of holders that are of the "outside" support category; 
naturally, Boyle recommends and teaches a holder of the "inside-the-bag" 
type. 
There are believed to be many inherent disadvantages of outside supports, 
including complexity, cost, the possibility of losing clamps or loose 
parts, etc. However, one such outside support has at least been proposed 
that would reduce at least one of the problems of the prior art--in that 
it reduces the number of parts to only two. This two-piece holder 
comprises a special elastic member (like a giant rubber band) that 
cooperates with a specially configured cardboard support; this holder is 
disclosed in U.S. Pat. No. 4,338,979 to Dow entitled "Bag Holding Device 
and Process." However, as with all such constructions, a trash bag in a 
Dow holder is vulnerable because it is inside the holder--where it comes 
into contact with all kinds of things that can tear the wall of a bag. 
That is, the sharp edge of a can or the thorns of a rose bush could easily 
puncture and then proceed to introduce a longitudinal tear in an 
unprotected bag that is resting inside the holder. Persons who have had 
experience with thorns starting at the top of a bag and ripping their way 
all the way down to the bottom of a polyethylene bag will clearly 
appreciate the deficiency of supporting a bag upright but leaving its 
sides exposed to tearing elements. The typical result of using such a 
holder to collect thorny refuse is that grabbing the top of the plastic 
bag and lifting it out of the holder causes the immediate dumping of all 
the accumulated trash onto the ground adjacent the holder. 
The aforementioned Boyle holder, on the other hand, is an inside-the-bag 
support, and it does seem like it might solve at least a few of the 
problems associated with outside supports. However, it is believed that 
even a Boyle holder is not perfect, in that the effort to make it a truly 
"universal" holder for all kinds and sizes of trash bags has required such 
compromises as to render the holder less efficient in some ways than it 
could be. For one thing, the desire to fabricate a Boyle holder out of 
economical cardboard and yet make it expandable in girth has required that 
the side panels be arranged as a serial array of panels that are not 
connected along one "edge." The result is what may be referred to as a 
"wrap-around" holder that includes one very long piece of cardboard having 
a length that ideally exceeds the maximum anticipated circumference of the 
bags that are to be held. (In this regard, it should be known that even a 
conventional 33-gallon trash bag has a circumference of about five feet, 
and some 55-gallon bags have a circumference of nearly eight feet.) Of 
course, if the circumference of the bag is not exceeded, so that there is 
no overlap of the two ends of the wrapped holder, than at least part of 
the plastic bag will remain unprotected by virtue of the gap in the 
cardboard "wall" when the holder is installed. And to paraphrase an old 
saying about the strength of a chain, a holder that is intended to provide 
tear protection for the walls of trash bags is only as good as the weakest 
part of the holder/bag combination. Expressed in other words, if any part 
of a vulnerable trash bag is left unprotected, then the entire bag is 
subject to becoming sufficiently damaged that the entire bag can fail. 
Another way of evaluating a trash bag holder is based upon the recognition 
that trash bags (somewhat like eggshells) do not generally fail in part; a 
bag is either totally successful in keeping its trash contained--or it is 
usually considered to be a failure by its user. That is, no one takes any 
real satisfaction that only half of a trash bag's contents have spilled 
onto a freshly swept side-walk or driveway--when one side of a bag rips. 
In the real world of trash removal, then, there is no room for partial 
success of trash bags. 
Another deficiency of a wrap-around holder like that shown by Boyle is that 
it can be efficiently used only in the mode in which it is shown in the 
figures of the Boyle patent--namely, upright. That is, if a Boyle holder 
is truly collapsable (for compact storage) as he claims, then there is no 
guaranteed way of keeping the holder--and hence a bag--open when it is 
lying on its side. Those persons who like to first accumulate leaves in a 
pile and then sweep them into a horizontally oriented bag would likely 
need the aid of an assistant in order to grasp and hold a Boyle device in 
an open condition in order for it to receive leaves. Turning what could be 
a one-man yard job into a two-man job is not what most people would 
consider to be progress, unless one's goal is perhaps to try to cure the 
world's unemployment problem. 
It follows, therefore, that there remained a need for a satisfactory way of 
efficiently supporting flexible bags in at least a temporary fashion so 
that they can be filled with refuse, while at the same time protecting all 
of the side walls of the bag from being ripped by a sharp edge. It is an 
object of this invention to provide such a holder and do so in an economic 
manner. 
Another object is to provide a holder for flexible bags which can be stowed 
in a relatively flat condition so that it occupies a minimum amount of 
space, while at the same time providing a stable construction for holding 
a bag in such a way as to encompass the maximum volume of space permitted 
by the geometry of the bag. 
A further object is to provide a holder that is stable and not subject to 
collapse when in either a horizontal and a vertical mode, so that leaves 
or other refuse can be accumulated in a trash bag by a single person using 
either the "vertical dump" or the "horizontal sweep" method of trash 
loading. 
These and other objects will be apparent from a reading of the 
specification and the claims appended thereto, as well as reference to the 
several figures of the drawings provided herewith.

BRIEF DESCRIPTION OF THE INVENTION 
In brief, this invention relates to a foldable holder having planar 
sections, said sections being connected to one another along adjacent 
edges so as to form a closed or tubular body. The preferred material for 
the planar sections or panels is corrugated paperboard--which is commonly 
referred to by many people as cardboard. Another suitable material is a 
rigid foamed plastic having closed cells on its exposed surfaces or at 
least a completely smooth sheet of thin material attached to said exposed 
surfaces in such a way as to be integral therewith. The preferred 
configuration includes four connected panels which are sized to create a 
square-shaped holder when the panels are moved to their fully expanded 
condition. Two opposite panels are scored vertically along their 
mid-regions so that they may be folded internally until they touch--or 
nearly touch, thereby allowing the other two sides to be brought together 
in a parallel fashion. The collapsed mode for the holder (wherein two 
sides are folded inwardly and two sides are brought very close together) 
constitutes a very handy storage condition for the holder, so that it 
might be tucked behind an appliance such as a stove or hung in a closet 
when it is not in use, thereby consuming a minimum amount of useful space. 
The sizes of the respective panels are designed so that the circumference 
of the expanded holder will be as large as the nominal circumference of 
the bag that is to be supported, but not more than about 2% greater than 
the nominal circumference of the bag, whereby a very slight stretching 
action may be required in order to insert the holder inside a bag. A 
slightly stretched plastic bas will tend to hold the expanded holder in 
its full-open condition, such that no auxiliary clips, braces or frames 
are needed in order to maintain a holder open. The length of the holder, 
as measured in a vertical direction when the bag is held in its upright 
and open condition, will be sized to extend from the bottom of an open bag 
to a few inches from the top of the bag, so that it would be possible to 
fold the top of the bag over the holder while it is being filled. 
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
Referring initially to FIG. 1, a holder 10 in accordance with this 
invention includes a set of serially connected structural panels that are 
joined together along certain of their edges in such a way as to form what 
may be called an elongated tube. In the embodiment illustrated in FIG. 1, 
there are four such structural panels, which are identified by the 
reference numerals 12, 14, 16, 18. The joint between panels 12 and 14 will 
be identified by the reference numeral 20; the joint between panels 14 and 
16 will be identified by the reference numeral 22; the joint between 
panels 16 and 18 will be identified by the reference numeral 24; and the 
joint between panels 18 and 12 will be identified by the reference numeral 
26. The joints 20, 22, 24, 26 are coextensive with what will be understood 
to be the length of the "tube," and this length dimension will normally be 
oriented vertically when the tube is positioned to support a trash bag in 
an upright condition. Two of the panels (i.e., panels 12, 16) have 
centrally positioned and longitudinal creases or score lines 28, 30 which 
give the respective panels a slight pre-disposition toward bending 
inwardly when the holder 10 is standing upright. But these score lines 28, 
30 do not rigidly restrict the panels 12, 16 to folding inwardly; under 
certain circumstances these panels can take on a slightly outward cant, 
such that the holder will appear to be bulged outward along two opposite 
sides. By virtue of the score lines 28, 30, the holder is switchable at 
will between its expanded mode (FIG. 1) and a collapsed mode--without 
disconnecting any of the panels. 
FIG. 3 shows the holder 10 partially collapsed, and FIG. 4 is a top or end 
view of the holder when fully collapsed. From an examination of FIG. 4, it 
will be apparent that panels 14, 18 have been brought together so that 
they are both parallel and very close to one another. The central portions 
of panels 12, 16 are also brought very close together, such that they 
touch or almost touch one another, but they do not press against one 
another with sufficient force as to introduce any compression loads in the 
members. For convenience and simplicity, the two panels 14, 18 that always 
remain parallel will generally be referred to as side panels, and the two 
creased panels 12, 16 will be referred to as end panels. 
The length of the holder 10 is slightly less than the height of a trash bag 
for which the holder has been designed. Preferably, there is an excess bag 
length of about three to five inches, so that the top of a flexible bag 
may, if desired, be folded inwardly and over the top of the holder 10 (as 
shown in FIG. 2). Also, by deliberately making the holder 10 somewhat 
shorter than the bag length, there is a kind of built-in gauge or reminder 
to users that they should fill the bag no higher than the top of the 
holder, in order to leave at least some free length of bag material that 
can be gathered for the purpose of effecting some kind of tied condition. 
For example, a parent can instruct a child to fill a bag with leaves but 
to not fill it over the top of the holder, so that there will more likely 
be enough residual bag for installing a wire or plastic tie to hold a full 
bag closed. 
Most 26-gallon bags will have a height of about 36 inches, so a holder 
specifically designed for such bags would be expected to have a height of 
perhaps 30 inches. Most 33-gallon bags have a height of about 38 inches, 
so a holder 10 for such bags would be expected to have a height of about 
35 inches. Bags for holding up to 55 gallons of refuse will usually vary 
in height from about 50 to 58 inches, and a holder about 50 inches tall 
(when the holder is oriented vertically) will usually be desired. In this 
regard perhaps it should be mentioned that experimentation has revealed 
that a flexible polyethylene bag will usually remain pretty much in place 
around an "inside" holder 10 made of cardboard--if the circumference of 
the holder is within about 2% of the circumference of the bag to be held. 
That is, a 1.3 mil plastic bag will not usually slide down (or collapse to 
the ground) from its vertical position, even if the bag is larger than the 
holder, as long as the bag excess is within about 2% of the girth of the 
holder. And if the girth of the holder 10 is not more than 2% greater than 
the circumference of a polyethylene trash bag (at rest), it has been found 
that there is enough resilience in the material of commercially available 
trash bags so that they can be stretched to go around a fully opened 
holder. Indeed, to have the girth of an expanded holder 10 just slightly 
larger than the circumference of a bag will tend to add even more 
stability to the combination of a bag and holder, especially when the two 
end panels 12, 16 are caused to bow slightly outward--to what may be 
called an "over center" condition. 
A noteworthy characteristic of the holder 10 will be apparent when it is 
being used to receive leaves. It is characteristic of dry leaves that they 
tend to be crisp and non-planar; like a pile of potato chips, a loose pile 
of dry leaves will usually be "fluffy" and voluminous. Hence, dry leaves 
can frequently be compressed--by stepping on them--so that they can be 
made to occupy a space that is very much smaller than the space they 
occupy in their natural state. Therefore, many people will fill a trash 
bag about half full of leaves, and then swing one leg up, over and into 
the open top of the bag for the purpose of stepping on the leaves in order 
to compress them, thereby making it possible to put many more light-weight 
leaves in a given bag. With the holder 10, any vertically directed force 
imposed by the weight of a person's body in stepping on leaves, and any 
consequential horizontal force that might tend to stretch and burst a 
trash bag, can be resisted by the totally connected walls of the holder 
10--which have a significant tensile strength. Cardboard of the type used 
in large shipping boxes is the preferred material for the holder 10, and 
such cardboard has a rated bursting strength of 200 pounds per square 
inch; the actual tensile strength is usually much more than that, of 
course. It is perhaps worth mentioning here that the common act of leaf 
compression by stepping in a bag of leaves would be unwise with a 
wrap-around holder of the type disclosed by Boyle, because there is 
nothing in a wrap-around holder to resist the transverse (bursting) loads 
that would be imposed on a plastic bag as someone tried to compress the 
leaves. 
A further advantage of the particular device is that it will protect the 
arms and hands of a person who is carrying a full bag of rose bush 
clippings, dry branches, thistles, stickers or other things which have 
sharp points and which might otherwise pierce the wall of a bag and 
scratch an arm or hand that is embracing the bag. Therefore, a trash bag 
that is filled with sharp and potentially injurious thorns or the like can 
be more safely transported to the trash collection site. 
To foster convenience in placing trash into a holder 10, and to make 
withdrawal of the holder from a full bag easier, it is advantageous that 
the panels of the holder 10 have a smooth surface with a coefficient of 
friction that is relatively low. If the panels 12, 14, 16, 18 are made of 
corrugated paperboard (i.e., cardboard), it may be advantageous to also 
treat them with Michelmon, a product available from Mobile Chemical 
Company that tends to improve the properties of cardboard, including 
making it more nearly waterproof and improving its surface finish, etc. 
Alternatively, cardboard panels could be coated, as with a waxy material, 
to lower their coefficient of friction with respect to such materials as 
are commonly handled as refuse. If the panels are made of relatively rigid 
and self-supporting plastic sheets, no surface treatment will usually be 
required in order to realize the desirable surface qualities for panels. 
Another advantage of the holder 10 (in comparison with other holders having 
non-connected panels) is that it is as fully self-supporting in its 
horizontal mode as it is in its vertical mode. In other words, when it is 
lying on one of its sides, the holder 10 does not need any wire braces or 
rigid supports to keep it open. It would therefore, be possible for 
someone to insert a collapsed holder 10 into a limp trash bag and then 
push the two sides 14, 18 apart, thereby expanding the bag to its full 
capacity. The bag and its holder could then be laid on the ground beside a 
pile of leaves, and the leaves could be swept into the open mouth of the 
bag without any assistance from another person. When the bag is at least 
partially full, the holder 10 can be turned upright and the leaves 
compressed in the bottom of the bag--by pushing downward on them. If a 
substantial fresh space has been created by the compressing step, the 
holder may be switched back to its horizontal orientation, or it may be 
left vertical. Any thorns or other sharp objects will not affect the sides 
of the bag during loading, because they will slide harmlessly along the 
hard walls of the holder 10. When the bag is as full as the user desires, 
the holder 10 is simply grasped at the top and lifted, leaving the bag and 
its contents behind. 
It may be that any thorns in the refuse will at this time puncture the bag 
wall--because of the absence of the protective holder 10. But a mere 
puncture is normally not enough to cause a bag to become destructively 
torn, as long as there are not any external forces acting on the bag. In 
other words, a polyethylene bag can be subjected to a great amount of 
tension and it will not tear, as long as there is no place (like a 
puncture) for a tear to start. But even a bag with puncture holes will 
normally not tear if it is subjected to only lifting loads, and there is 
no localized force applied near the puncture. It is for this reason that 
the holder 10 makes it possible to use ordinary polyethylene bags to 
accumulate what would otherwise be potentially destructive things such as 
rose bush trimmings. 
To produce a suitably sized holder 10 for holding very common 30 gallon 
trash bags (using the four-panel configuration), the side panels 14, 18 
will be advantageously sized as 15 by 26 inches; the end panels are sized 
as 15 by 26 inches, making the circumference of the opening 60 inches. The 
weight for such a holder (when 200 pound test cardboard is utilized) will 
be about 1.25 pounds. A holder for 33 gallon bags will typically have a 
slightly larger opening, with a circumference of 66 inches. The volume 
that can be encompassed by a 33-gallon holder will be about 5,850 cubic 
inches, and its weight will be about one pound and six ounces. When the 
holder 10 is collapsed (as shown in FIG. 4), it will encompass only about 
293 cubic inches, which is only about 5% of its expanded volume. Trash 
bags rated at 55 gallons routinely have a circumference of about 78 
inches, so the size of the opening for a holder for such large bags will 
be designed accordingly. 
While only the preferred parameters have been disclosed herein, it will be 
apparent to those skilled in the art that variations could be adopted 
without departing from the spirit of the invention. For example, so called 
dove-tail dies are used to make the creases in the end panels, so that 
they will have a natural bias toward folding inward. But other crimping 
tools could be used to produce other creases that have their own 
chacteristics. Also, the preferred style of bag holder is a four-panel 
holder--as shown in FIG. 1, but six or more panels could also be employed, 
as long as the holder can be converted to an essentially flat condition 
for storage. That is, the holder 10 is so bulky when it is expanded that 
it believed to be necessary that the number of panels be chosen so that 
the holder can be folded to a compact size when it is not in use. But in 
spite of its bulk, a cardboard holder 10 as illustrated herein for holding 
33-gallon trash bags will weigh only about one pound and six ounces.