Abstract
A cover for use with sacks for covering the mouth of a sack after it has been filled, to prevent its contents from spilling. One application is for recyclable yard waste sacks that are used to carry yard waste such as leaves, or used for carrying food scraps from restaurants. The sacks being made of paper so that they can be composted, require a cover that is made of paper that can be recycled as well. Some embodiments of the cover utilized a paper with a plurality of holes or die-cut slits that stretch into a hexagonal three dimensional shape when pulled, and contracts when released. The unusual elasticity afforded to ordinary paper by the slit holes patterns is used to create a sack cover that can stretch to close a sack without tearing. The elasticity is utilized to create sufficient griping force on the mouth of the sack to resist dislodgement of the cover when the sack tips over. A few embodiments of the cover utilize a hybrid design in which both ordinary and slitted paper are used. Other embodiments of the cover are made of ordinary paper with a drawstring.
Claims
1. A cover for a sack with a closed end, an open end, and a cover body, which extends between the two ends, comprising: expandable paper construction having an array of slit openings in the cover body in regular repeating patterns in the cover body in proximity to the open end; the paper construction on the closed end having a bottom; wherein the open end opens when an opening force pulls apart the perimeter edges of the open end of the cover which also makes the cover body grow into a larger three-dimensional structure; wherein the cover is deployed over the sack at the open end; and wherein when the opening force is removed, the sides of the cover in proximity to the open end of the sack retract, grip the sack so that the cover forms an open end closure on the sack and prevents the contents of the sack from spilling from the open end closure of the sack and the cover body contracts, closing the slit openings as much as possible, the cover conforming approximately to the shape and dimensions of the sack as much as possible where it overlaps the sack.
2. The cover of claim 1, wherein the cover comprises one or more paper sheets with the cover body having a plurality of slit openings in a pattern of spaced parallel rows of individual slits.
3. The cover of claim 2, wherein in the un-expanded state of the paper the slit openings in the cover body are substantially closed and form parallel lines that extend in the direction of the open end to the closed end.
4. The cover of claim 2, wherein the slit openings in the cover body in each row are positioned adjacent to the interval spaces between consecutive slit openings in a next adjacent parallel row of slit openings.
5. The cover of claim 1, wherein the said slit openings are generally similar in shape and size, in a consistent, uniformly repeating pattern.
6. The cover of claim 1, wherein the slit openings after expansion are hexagonal.
7. The cover of claim 1, wherein the cover substantially regains its original shape and size when the opening force is removed.
8. The cover of claim 1, wherein the paper is die cut paper with slit openings that expands-into a hexagonal honeycomb structure when the cover body receives an opening force.
9. The cover of claim 1, wherein the cover is shaped into a pinched bottom sack with tapered sides ending in a ridge or line at the closed end.
10. The cover of claim 1, wherein the cover is formed into a bag with a rectangular bottom at the closed end.
11. The cover of claim 1 wherein portions of the cover in the vicinity of the closed end are made of ordinary paper, and the portions of the cover in proximity to its open end are made of expandable paper which has a plurality of arrayed openings that expand when the sides of the cover are pulled apart with an opening force and contract when the opening force is removed.
12. The cover of claim 1 wherein the cover is comprised substantially of corrugated or pleated paper, and an elastic member made of expandable paper which has a plurality of arrayed openings that expand when the sides of the cover are pulled open with the opening force and contract when the opening force is removed, is incorporated in the vicinity of the opening of the cover such that it allows the opening of the cover to expand when pulled apart with the opening force, and to contract when the opening force is removed.
13. A method of covering a sack with a cover comprising: c) expanding the sides near the opening of a cover made with expandable and retractable paper having an array of slit openings formed into an enclosure withan open end, a closed end, and a cover body which extends between the two ends, by subjecting the cover to an opening force that pulls apart the perimeter sides of the cover near the open end, and the cover body near the open end causing the slit openings to open wider, and the cover to get bigger; d) applying the opening force to the cover so that its open end is larger than the sack, then positioning the open end of the cover over the open end of the sack; c) removing the opening force on the perimeter sides of the cover near its open end, wherein-when the opening force is removed from the cover's open end, the cover retracts and grips the sides of the sack, so that the cover forms a closure of the sack and substantially prevents the contents of the sack from spilling, the cover body substantially conforming to the shape and dimensions of the sack where it overlaps the sack.
14. The method of claim 13, wherein the method comprises expanding the cover made of expandable paper with an opening force, where the majority of the slits of the paper are unopened and the slits form vertical lines running from the closed end to the open end; and just prior to deploying the cover over a sack, the sides of the cover in the vicinity of the open end of the cover are stretched by hand to cause a minimum number of slit openings in the vicinity of the open end to open and expand the opening of the cover, so that the cover can be positioned over a sack that is larger than the cover.
15. The method of claim 13 wherein the method comprises using an opening force on the perimeter sides of the open end of a cover made of flat or unexpanded paper, causing the cover opening to open just enough to fit the cover over the sack that it is covering.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is a perspective view of a pinched bottom sack made of expandable slitted paper prior to being expanded.
(2) FIG. 2 is a perspective view of a pinched bottom that has been expanded by stretching the paper.
(3) FIG. 3 is a perspective view of a Yard waste sack that has been closed with a pinched bottom sack made of slitted paper.
(4) FIG. 4 is a perspective view of a Yard waste sack that has been closed with a rectangular bottom merchandise style sack made of slitted paper.
(5) FIG. 5 is a perspective view of a pinched bottom sack made of ordinary paper with a drawstring around its opening.
(6) FIG. 6 is a perspective view of a pinched bottom sack made of ordinary paper with a drawstring around its side having a locking collar.
(7) FIG. 7 is a perspective view of a yard waste sack that has been closed with a pinched bottom sack made of ordinary paper having a drawstring that has been tied in a knot.
(8) FIG. 8 is a perspective view of a Yard waste sack made of ordinary paper with a drawstring around its opening closed with a locking collar.
(9) FIG. 9 is a perspective view of a pinched bottom sack made of ordinary paper with an elastic member attached around its opening.
(10) FIG. 10 is a perspective view of an elastic member.
(11) FIG. 11 is an elastic member for a sack made of expandable slitted paper.
(12) FIG. 12 is a perspective view of a pinched bottom sack made partly of ordinary paper and partly of slitted paper.
(13) FIG. 13 is a perspective view of a pinched bottom sack made of pleated or corrugated paper.
(14) FIG. 14 is a section view of the wall of a sack made of pleated paper with an elastic member made of expandable slitted paper attached on one side.
(15) FIG. 15 is a section view of the wall of a sack made of pleated paper with an elastic member made of expandable slitted paper attached on both sides.
(16) FIG. 16 is a perspective view of a yard waste sack closed with a pinched bottom sack made partly of ordinary paper and partly of slitted paper.
DETAILED DESCRIPTION OF THE INVENTION
(17) A first embodiment of the stretchable cover is shown in FIG. 1. Flat Geami paper has been shaped into a pinched bottom paper sack. One end of the sack is open while the other end is closed with the sides tapering to a line or ridge. The holes are substantially closed and appear as slits. As used here, the term expanded position refers to the condition of the paper where after it has been extended by a pulling force, where at least 25% of the slits or openings in the paper have increased in area to at least 25% of the area that each would have at maximum extension when the paper begins to tear. This expanded position is shown in FIG. 2. The term un-expanded refers to the paper with closed openings as shown in FIG. 1. Sheets of unexpanded paper are at nominal dimensions comparable to ordinary paper without slits. In another embodiment, sheets from the manufacturer are already in an expanded or semi-expanded state, and are further expanded when used to cover the sac.
(18) FIG. 2 shows a pinched bottom sack made of Geami paper that has been expanded. The die cut holes in the paper have opened up allowing the paper to expand or stretch. In use the pinched bottom sack is put over the mouth of a yard waste sack like a wool knit cap on a person's head so that the closed end is at the top of the yard waste sack. Hence the pinched bottom sack forms a cap for the yard waste sack. The pinched bottom sack can then be called a cap.
(19) FIG. 3 shows a yard waste sack 11 that has been fitted with a cover 10 made of Geami paper in a pinched bottom sack design.
(20) FIG. 4 shows a yard waste sack 11 that has been fitted with a cover 12 made from Geami paper in the design of an ordinary merchandise bag with a rectangular bottom.
(21) FIG. 5 shows a pinched bottom sack 13 made or ordinary paper with a piece of string 14 attached to it along the periphery of the opening of the sack and is used to effect a closure of the sack. The string runs along the edge of the opening of the sack through an enclosure, channel, or loops inside the walls of the sack and its ends emerge together in front of the sack. The string is threaded through an enclosure within the walls of the sack and is preferably not sewn, or rigidly attached to the sack so that it can be pulled within the sack. When the two ends of the string 14 are pulled while holding the sack, the string constricts the opening of the sack making it smaller and effecting a closure of the sack. The string is thus a drawstring for closing the mouth of the sack. The string can be tied into a knot to prevent it from loosening. The string can also be sewn to the sack so that when the string is pulled it pulls a portion of the sack with it and causes a closure of the sack. When the string is attached to the sack only one end may be pulled to effect closure of the sack.
(22) FIG. 6 shows a pinched bottom sack 13 with a string 14 running along a periphery of the sack. The string is enclosed inside a tubular enclosure, channels or loops, 17 which is part of the sack so that the string is free to move inside the enclosure. The two ends of the string pass through a hole in collar 15 made, preferably of cardboard or other recyclable material. The hole in collar 15 being barely big enough to contain the two lengths of string within it, constricts the two lengths of the string within the collar and prevents the string from loosening. The collar thus allows the length of string within the sack to form a noose which when tightened by pulling the free ends of the string through the collar while holding the collar or the sack, constricts the opening of the sack and forms a closure of the sack. The collar thus performs the same function as the knot in the string as described in FIG. 5 above serving as an adjustable knot that can moved up or down along the string to tighten or loosen the sack.
(23) FIG. 7 shows a sack 16 which may be a yard waste sack or shopping bag. A pinched bottom sack 13 with a string 14 permitting its closure has been used to close off the opening of the sack 16. The string 14 is enclosed inside a tubular enclosure, loop, or channel 17 which is part of sack 16. By pulling the sack 13 over a sack 16 which is full of yard waste, goods or other material and thus has a substantially cylindrical shape, the sack 13 can be secured around the sack 16 by pulling string 14 to tighten the sack 13 around the sides of sack 16. The sting 14 can then be secured from loosening by tying it in a knot 18.
(24) FIG. 8 shows a second sack 16 whose opening has been covered with a pinched bottom sack 13 having a tubular enclosure, loop, or channel 17 along the periphery of its opening. A string 14 passes through the enclosure 17 and secures the sack 13 around sack 16 by means of the collar 15 previously described in FIG. 6. The string can also be constrained from loosening by any number of mechanisms used in Industry for the purpose including being pinched by a cam within a housing or being pinched by a spring loaded cam or other member. The Clothing and sailing industries in particular have many such mechanisms serving this purpose.
(25) FIG. 9 shows a pinched bottom sack made of paper e.g. Kraft paper 13. An elastic element 18 is attached along the periphery of the opening of the sack and serves to constrict the opening of the pinched bottom sack around the sides of another sack when it is used to close off the opening of the other sack. The elastic element 18 can be made of rubber or other elastomers but is preferably made of a recyclable material like paper.
(26) FIG. 10 shows an elastic element 18 such as described in FIG. 9 above.
(27) FIG. 11 is an elastic element 19 that is made of Geami paper with slitted holes that expand into a hexagonal honeycomb structure when pulled causing the paper to stretch. The elastic element 19 can be made of a single layer of Geami paper or similar paper, or it could be comprised of two or more layers of this elastic paper. When attached along the periphery of a sack e.g. a pinched bottom sack as described in FIGS. 9 and 10 below, the Geami paper constricts the pinched bottom sack against another sack e.g. a yard waste sack to close off the sack. The Geami paper is recyclable so that a pinched bottom sack with an elastic Geami paper band is recyclable.
(28) FIG. 12 shows another embodiment of a composite sack made of ordinary paper 20 and Geami paper 22. The top portion of the sack is a pinched bottom sack made of ordinary paper 20 like Kraft paper. The lower portion of the sack has a skirt of Geami paper 22 attached to it e.g. by gluing, sewing, stapling or any number of methods known to industry. Geami paper stretches when pulled, so that making a pinched bottom sack entirely out of Geami paper might require some specialized equipment and procedures. By making the part of the sack that requires the most handling e.g. pulling cutting and folding out or ordinary paper in a standard operation, and merely gluing a skirt of Geami paper to the ordinary sack, this composite sack can simplify the task of manufacturing an expanding paper sack. The upper portion of the sack made of ordinary paper 20 does not stretch when used to cover another sack but it defines the shape of the sack. A strip of Geami paper 22 glued to the edges of the pinched bottom sack 20 make it longer while providing it with an elastic skirt 22 that will stretch and press against the sides of another sack when used to cover the sack. The Geami paper skirt 22 can be made of one or more layers of Geami paper to increase the force of elasticity, i.e. the springiness of the paper is increased. A cover of this type can also be made from sheets of paper that are not fully covered in slits. Leaving areas of a sheet of paper without slits will accomplish the same effect as joining a skirt of paper with slits to a cover made of paper that does not have slits. This approach may provide some benefits in the manufacture of a cover by providing a paper that does not easily stretch in undesired areas due to the stiffness of the areas without slits.
(29) FIG. 13 shows a paper sack made of pleated or corrugated paper 21. The pleats allow the paper sack to be made oversized and would have fit loosely on the sack, but the excess space is taken up by the pleats or corrugations. When a covering sack e.g. a pinched bottom sack is made in this way it will fit over the mouth of a sack being closed. The pleats will unfold and allow the sack to expand and accommodate the sack it is closing off. The elasticity of the paper will provide the elastic force needed to constrain the pinched bottom sack against the sides of the sack being closed.
(30) FIG. 14 is a partial view of a section of the wall of a sack. It shows how the elasticity of a sack made of corrugated paper 21 can be increased. A layer of Geami paper is glued or otherwise attached to the corrugated walls 21 of a paper sack along a portion e.g. the peaks of the corrugations. When the sack is fitted over another sack to close the second sack off, the pleats or corrugations of the closing sack will unfold and allow the sack to expand. When this happens the Geami paper 22 will stretch, and because it is elastic it will increase the elastic force of the corrugated sack enabling the sack to grip tighter on the sack whose mouth is being closed. Without the addition of the Geami paper 22 the elasticity of a corrugated sack made of ordinary paper may be too small or weak to adequately grip a sack being closed off strongly enough to secure its contents from spilling when the sack is tipped over. In FIG. 14 the Geami paper is attached to one side of the sack.
(31) FIG. 15 shows a section view of a sack made of corrugated paper 21 as described above. This time the Geami paper 22 is attached on both sides of the corrugated paper walls. The double layer of Geami paper increases the elastic spring force of the walls of the sack over what would be possible with only a single layer of Geami paper thus increasing the force that a sack made of this type of material can grip the sides of a sack being closed off, thereby effecting a more secure closure of the sack.
(32) FIG. 16 shows the composite sack of FIG. 12 used to secure a yard waste sack. The gripping force is provided by the Geami paper 22. The shape of the Pinched bottom sack is defined by the upper part 20 which is made of ordinary paper e.g. Kraft paper.
(33) Although the present invention has been described with reference to several embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the invention.
