THERMOFORMED PLASTIC WRAP DISPENSER

Abstract: The dispenser (20) is provided for containing and dispensing sheet wrapping material (102) such as plastic film. The dispenser includes an elongated body having a pair of like confronting hollow body shells (22, 24). Each of the body shells has a pair of adjacent longitudinal edges (83) interconnected by an integral hinge (78). There are also confronting longitudinal edges. Each body shell has a cross-section of an isosceles triangle whereby the body has a square cross-section. The body shells also have end walls (32, 34, 70, 72) with confronting pairs thereof having means (60, 76) for retaining such end walls in confronting relation. An integral cutting member (26) is hingedly connected to the confronting longitudinal edge of one of the body shells closely adjacent to a side wall (28) of the other body shell.

Description: Flexible wrapping materials such as plastic film and waxed paper are conventionally supplied in pasteboard cartons. A roll of the wrapping material is housed within the carton and is intended to rotate as one pulls on the material at the end of the roll, thereby to dispense the material necessary for wrapping a package, which may be leftover food, etc. The pasteboard carton is provided with a metal cutting edge, generally serrated for cutting off the desired quantity of wrapping material when it has been withdrawn from the carton. Such dispensing cartons have proved to be unduly expensive as compared with the contents of the carton. Several individual stages of production are necessary, all of which increase the cost. These stages include die cutting and scoring of the blanks, stamping of the metal cutter bar, crimping bar onto each blank, set-up and gluing operations, and finally filling the container. Each such stage increases the cost of the carton or container, and hence of the item as sold. Furthermore, it occasionally occurs that a user will cut a finger on the metal cutter bar. This cutter bar is stamped of thin sheet metal, and is quite sharp. Such cutting is uncomfortable, unsightly and potentially dangerous. To overcome these drawbacks wrap dispensers have been described such as in GB-A-2 088 330 thermoformed in one piece with a spout protruding from the housing through which the wrap can be withdrawn. It is the object of the present invention to provide a dispensing container with a substantially square cross-section for film or sheet packaging material such as film plastic, wax paper, aluminum foil, etc., which is completely thermoformed in one stage of a suitable plastic material and in which a cutting edge is formed integrally with the remainder of the container in the same forming operation. This object of the invention is attained by a dispensing container for a roll of sheet material for wrapping articles comprising: an elongated one-piece thermoformed body having a pair of confronting hollow body shells interconnected by an integral hinge strip, each of said body shells having a pair of side walls and an opposing pair of end walls and wherein each end wall has integral retaining means with cooperating parts which are dimensioned to have an interference fit therewith to hold the body shells together in a closed position, said body shells are movable into face to face relation about said hinge, strip between open and closed positions to form a container of substantially square cross-section when in closed position, and a retention and tear-off flap integrally connected to one of said body shells along a second hinge strip said retention flap being foldable into proximity with one side wall of the other body shell for retaining an end portion of the sheet material in a position between said side wall and said retention flap. The different embodiments are characterized by the features of the dependent claims. In more detail, the present invention provides a thermoformed elongated structure comprising two integral convex-concave shells each of triangular cross-section plus an integral flap having a formed cutting edge thereon. The two triangular shells are interconnected by an integral hinge, and the shells are foldable into face-to-face relation to form a container of substantially square cross-section. Structure is provided at the opposite ends of these shells to hold them in the aforesaid face-to-face relation. A flap is joined to one of the triangular sections by an integral hinge, and it is foldable into confronting relation with one side of one of the triangular shells, the integral hinge overlying the open juncture between the triangular shells. Structure on the flap interfits with structure on the adjacent triangular shell for holding the flap in closed condition, whereby flexible packaging material such as film plastic is held in position for access for subsequent withdrawal. The invention will best be understood from the following specification when taken in connection with the accompanying drawings, wherein: Figure 1 is a plan or lay-out view of a thermoformed plastic wrap dispenser before folding into closed condition; Figure 2 is an end view thereof; Figure 3 is an enlarged sectional view taken along the line 3-3 in Figure 2; Figure 4 is an enlarged sectional view taken along the line 4-4 in Figure 2; Figure 5 is an enlarged sectional view taken along the line 5-5 in Figure 2; Figure 6 is an enlarged cross-sectional view through the dispenser as folded in to using shape and including a roll of sheet packaging material such as plastic film; Figure 7 is a detail view of the latch for the tear-off flap as taken substantially along the line 7-7 in Figure 1; Figure 8 is a lay-out or plan view similar to Figure 1 showing a modified form of the invention; Figure 9 is an end view thereof; Figure 10 is a view similar to Figure 6 showing the modified form of the invention as illustrated in Figures 8 and 9; Figure 11 is a lay-out or plan view similar to Figure 1 showing a further modification of the invention; Figure 12 is an end view of the modification of Figure 11; Figure 13 is an enlarged cross-sectional view as taken along the line 13-13 in Figure 11; Figure 14 is an enlarged cross-sectional view as taken along the line 14-14 in Figure 11; Figure 15 is a detail view showing the latching of the cut-off flap in closed position as taken along the line 15-15 with the dispenser folded into closed, operating position; Figure 16 is a detail view of a corner of the cut-off flap on an enlarged scale; Figure 17 is an enlarged sectional view as taken substantially along the line 17-17 in Figure 11; and Figure 18 is a cross-sectional view on an enlarged scale similar to Figures 6 and 7 but showing the embodiment of Figure 11. Turning now in greater specificity to the drawings, and first to Figures 1 and 2 there is shown a thermoformed plastic wrap dispenser 20 in non-assembled or knock-down form comprising a first convex-concave body shell 22 having a cross-section of an isosceles triangle, a second convex-concave isosceles triangle body shell 24, and a substantially flat retention and tear-off flap 26. The thermoforming art is well-known, and it will be understood that a sheet of suitable plastic is heat softened to a desirable degree and then conformed to a female mold by gravity and differential air pressure. The three parts of the knock-down dispenser are simultaneously formed in a common mold, and the three parts are integral with one another as will be set forth in detail hereinafter. The first body shell 22 comprises a pair of sidewalls 28 and 30, and a pair of end walls 32 and 34. The sidewalls 28 and 30 are at right angles to one another and are integrally interconnected by a relatively narrow corner wall 36 which is arranged at 45°to either wall 28, 30. Midway from end-to-end the corner wall 36 is depressed and widened at 38 to form a recess (see also Figure 6) for easy gripping of a plastic film or the like dispensed from the dispenser as will be brought out in detail hereinafter. The recess or depression 38 is connected by tapered sections 40 to the corner wall 36. The sidewall 28 is nominally flat, but is provided with a first depressed portion or panel 42 for rigidity, and a second depressed and inclined panel 44 having at its free edge an outwardly curled lip 46. The end wall 32 is joined to the first sidewall 28 at a substantially right angle 48 (Figure 3). The end wall 32 has a recessed panel 50 for strength and rigidity and which opens to the side wall 28 to provide for clearance of a retaining flange on the flap 26 as will be apparent hereinafter. The outer edge 52 of the end wall (the base of the isosceles triangle) is provided with an outwardly projecting right angle flange 54 tapering in at its ends 56 and 58. The flange is provided with an elongated trough or depression 60 overlapping the end wall 32. The end wall 34 is a mirror image of the end wall 32 and includes a similar flange 54 and trough or recess 60. The narrow wall 36 is joined to both of the end walls 32 and 34 by an angled section 62 which facilitates molding and provides a more secure and rigid corner. The second body shell 24 need not to be described in detail, since it is very similar to the first body shell 22, having first and second recessed sidewalls 64 and 66 interconnected by a narrow wall 68. The second body shell 24 is provided with recessed end walls 70 and 72, and tapered flanges 74 are provided on both end walls, the flanges having upward protuberances 76. The protuberances 76 are similar to but smaller than the troughs or recesses 60 and are dimensioned to have an interference fit therewith. The sidewall 30 of the first body shell 22 is integrally joined to the sidewall 64 of the second body shell 24 by a hinge strip 78. The hinge strip 78 as best seen in Figure 2 comprises a central rib 80 running from end-to-end thereof, and thinner areas 83 lying on either side thereof and immediately adjacent the respective body shells. This construction localizes the bending or hinging effect so that there is a localized 90° bend in each narrow side strip 83 in bringing the end wall edges substantially into engagement with the flanges 54 contacting the flanges 74, and with the protuberances 76 received in the recesses or troughs 60 as shown in Figure 6. The film retention and cut-off flap 26 is substantially flat, and is provided with a plurality of external ribs 82 extending from end-to-end thereof. The flap is also provided with depressions 84 extending from end-to-end of the flap. These ribs and depressions strengthen the flap and render it more rigid. The adjacent edge of the flap 26 is joined to the sidewall 66 of the second body shell 24 by an integral hinge 86 similar to the hinge 78, comprising a central rib 88 and two narrow flexing sections 90. Each of these flexing sections has to bend only 45°as may be seen with reference to Figure 6 to bring the flap 26 into proximity with the sidewall 28 of the first body shell 22. The free edge 92 of the flap 26 is straight from end-to-end, and on its outer surface is flat. However, the inner surface is provided with a large number of parallel transverse indentations 94 (Figures 1 and 7) essentially defining a serrated edge having a plurality of cutting teeth 96 thereon. The flap 26 is completed by provision at each end of a flange 98 projecting inwardly from the flap 26 at slightly less than 90°. A narrow peripheral flange 100 strengthens the flange 98 and renders it more rigid. The body shells 22 and 24 are hingedly moved toward one another with a roll of sheet wrapping material 102 therein as shown in Figure 6. This sheet wrapping material preferably is a plastic film but could be wax paper, aluminum foil, or other suitable material. The body shells are brought into confronting relationship with the protuberances 76 received in the troughs 60 to hold the body shells together with some of the sheet wrapping material 102 extending past the lip 46 and out far enough that the flap 26 can be brought into substantially contacting relation with the adjacent sidewall 28, the flanges 98 gripping the end walls 32 and 34 frictionally to hold the flap in the position shown in Figure 6. The end 104 of the plastic film or other sheet wrapping material 102 extends past the edge 92 of the flap. Thus, as much wrapping material as desired may be pulled from the roll, and then torn off along the edge 92. Transverse pressure on the edge outwardly away from the dispenser tends to bow the edge slightly outwardly, and this pulls the end flanges 98 into tighter engagement with the end walls of the first body shell 22. The completed thermoplastic wrap dispenser with the wrapping or packaging material therein is identified by numeral 106. A modification of the invention is shown in Figures 8-10 which is similar to the embodiment previously described in connection with Figures 1-7. Similar parts are identified by like numerals with the addition of the suffix a to avoid prolixity of disclosure. Differences reside in the sidewall 28a and in the retention and tear-off flap 26a as now will be described. The ends of the sidewall 28a as identified at 108, and the interconnecting portion 110 lying along the narrow connecting wall 36a are substantially flat and coplanar. A panel 112 upstands from the coplanar portions 108, 110 providing a substantially right-angle wall 114. The panel 112 and wall 114 are recessed at 116 and 118, to provide clearance for the recess 38a. The panel 112 slopes from the top of the wall 114 nearly to the free edge of the sidewall 28a, the sidewall at this position being formed as a V-shaped trough 120 having a free edge 122. The flap 26a is formed to conform to the outer surface of the sidewall 28a. Specifically, it has a flat, coplanar periphery comprising end sections 124 and 126, and an edge portion 128. Adjacent to the hinge 86a there is a single longitudinally extending stiffening rib, and from the edge of this rib a panel 130 extends outwardly at a shallow angle, being terminated by a right-angle wall 132. The central portion of the wall 132 is recessed at 134 as is the panel in this area. The outer edge 92a of the flap 26a is serrated in outline as may be seen at 136, and these serrations extend both above and below the plane 128, thereby to provide superior cutting edge. An offset 138 extending from end-to-end of the flap is provided inwardly from the edge 92a to enhance the strength and rigidity of the edge portion of the flap. As will be seen in Figure 10, the plastic film 104a or other sheet material is gripped between the conforming right-angle walls 134 and 114 of the flap and the sidewall, whereby more positively to hold the film in place after an extracted portion thereof has been torn off. The flap must be pivoted slightly outwardly to free the film so that more film may be withdrawn past the edge 122, the flap again being brought into gripping position with the sidewall before the film is torn off, whereby to hold the film against any possible retraction. A third form of the invention is shown in Figures 11-18. Most of the parts again are the same or nearly so, and similar parts are identified by like numerals with the addition of the suffix b . In this embodiment of the invention the dispenser 20b includes somewhat simpler construction than in the previous embodiments. Thus, in the body shell 22b the sidewalls 28b and 30b are flat throughout and meet at a right-angle corner 36b rather than at champfered corners. The relief area 38b for gripping the plastic film or other sheet material is substantially smaller. The end walls 32b and 34b are flat with the exception of elongated indentations 140 adjacent to and parallel to the sidewall 28b. The purpose for these indentations will be set forth hereinafter. The sidewalls 64b and 66b also are flat throughout and meet at a right-angle corner 68b rather than having a cut-off corner as in the previous embodiments. The end walls 70b and 72b are flat, and at the free or base edges are provided with outward offsets 142 and then outwardly extending and inwardly angled flanges 144 reinforced by peripheral flanges 146. When the body shells are folded into confronting relation as shown in Figure 18 with a roll of sheet wrapping material 102b therein the flanges 144 frictionally grip the end walls 32b and 34b to hold the dispenser in closed position. The first and second body shells 22b and 24b are interconnected by an integral hinge 78b similar to that disclosed in connection with the previous embodiments of the invention, but having the projection or rib 80b directed upwardly or inwardly, the opposite of the previous embodiments. The flap 26b is mostly flat, and is provided with an end-to-end central channel 148 to strengthen and render the flap more rigid. The flap is provided at the opposite ends with flanges 98b similar to those described in connection with Figures 1-7. The outer end of each flange is received within the indentation 140 of the respective end walls 32b and 34b as shown in Figure 15 to hold the flap in the closed position of Figure 18 with the end of the plastic film 104b extending therepast. The edge 92b is sharp as provided by a taper 150 shown in Figure 18. Alternatively, as shown in Figure 16 the edge may be serrated for improved tearing. There are many plastic resin materials which could be utilized to manufacture the thermoformed plastic wrap dispenser as herein shown and described. One material that we have found to be satisfactory is high impact polystyrene. A sheet of such polystyrene having a thickness of .035 inches (0.9mm) has been used as stock, resulting in an average wall thickness of .020 to .025 inches (0.5 to 0.6mm). The plastic thermoformed dispenser, carton or container as heretofore shown and described presents many advantages over contemporary commercial containers made of pasteboard with a metal cutter bar. Considerable expense is saved in eliminating the cutter bar, a manufacturing step is avoided in having an integral rather than an attached cutter, and the plastic cutting edge as herein shown is much less likely to cut the fingers of a user than is the current metal cutter bar which causes a significant number of injuries. A friction fit or interference fit of the retention and cutting flap in the present dispenser holds the end of the supply of plastic film in readily accessible position after a portion of the film has been torn off for use. This eliminates the need of a separate adhesive application as found in current cartons. The placement of the ridges on the inside of the flap in one embodiment augments the holding ability of the flap. The diagonal separation of the two body shells permits the retention and cut-off flap to be hinged to an edge of the body so that the flap overlies an adjacent surface of the carton. In addition, the diagonal division coupled with the thermoforming process allows the dispenser to be formed as a result of a single operation. Excluding the possibility of printing material, the container is complete and ready to fill directly after the single stage forming/trimming operation. The plastic material eliminates problems associated with current pasteboard or the like stock which is subject to moisture absorption. Current cartons also require gluing, forming, and metal cutting bar attachment in separate operations in production, all of which increase the complexity and cost of production. The thermoformed dispenser or carton is readily adapted for a nesting of parts in a production plant before the body shells are folded into confronting relation with an enclosed roll of plastic film or the like. Furthermore, the thermoformed dispenser or carton as herein shown and described can be re-used, thereby making it possible to sell bulk rolls of plastic film to be inserted in a used carton.

Claims: A dispensing container for a roll of sheet material for wrapping articles comprising: an elongated one-piece thermoformed body having a pair of confronting hollow body shells (22, 24) interconnected by an integral hinge strip (78), each of said body shells having a pair of side walls (28, 30 and 64, 66) and an opposing pair of end walls (32, 34 and 70, 72), wherein each end wall (32, 34 and 70, 72) has integral retaining means with cooperating parts (60, 76) which are dimensioned to have an interference fit therewith to hold the body shells together in a closed position, said body shells are movable into face to face relation about said hinge strip (78) between open and closed positions to form a container of substantially square cross-section when in closed position, and a retention and tear-off flap (26) integrally connected to one of said body shells (22, 24) along a second hinge strip (86), said retention flap (26) is being foldable into proximity with one side wall (28) of the other body shell (22) for retaining an end portion (104) of the sheet material (102) in a position between said side wall (28) and said retention flap (26). The dispensing container of Claim 1, characterized in that said retaining means comprise flanges (54, 74) extending from said end walls (32, 34 and 70, 72), one pair of flanges having protuberances (76) and the opposing pair of flanges having recesses (60) for interlocking engagement with each other when the body shells are in a closed position. The dispensing container of Claim 2, characterized by in that each flange (54 or 74) on the end wall of one body shell is substantially parallel to and is projecting beyond the respective end wall and in that said flange is positioned to engage the corresponding flange on the opposing end walls of the opposite body shell. The dispensing container of anyone of the preceding claims, characterized in that said tear off flap (26) is substantially as wide as the adjacent side wall and has parallel transverse indentations (94) which form a cutting edge thereon. The dispensing container of any one of the preceding Claims, characterized by means (98; 114; 134; 986; 140) on said retention flap (26) for latching said flap to said body shell (22). The dispensing container of Claim 5, characterized in that the latching means comprises interfitting parts on said flap and on said body shell. The dispensing container of Claim 6, characterized in that the interfitting parts comprise an outwardly projecting shoulder on a sidewall (70b) and a mating shoulder (98b) on said flap (20b) wedgedly engaging the side wall shoulder, said shoulders together gripping said sheet material therebetween. The dispensing container of Claim 7 characterized in that the interfitting parts comprise end flanges (98) on said flap (26) engageable with respective end walls (32, 34) of the body shell (22). The dispensing container of any of the preceding Claims, characterized in that a depression (38) is provided in said body shell (22) and in that said flap cutting egde projects beyond said depression (38) to permit gripping of the sheet material (102) between said flap (26) and said body shell.

Inventors: BEDNER, MARIA D., GULICK, JOHN J., KILDEA, JAMES A.
Applicants: DOWBRANDS INC. (A DELAWARE CORP.)
Application year: 1986
Main classification: B65D85
IPC codes: B65D83, B65H35, B65D85