US 3625270 A
Description (OCR text may contain errors)
United States Patent inventor Milorad Skendzic 110' West 69th St., New York, N.Y. 10023 Appl. No. 29,602 Filed Apr. 17, 1970 Patented Dec. 7, 1971 Continuation-in-part of application Ser. No. 817,080, Apr. 17, 1969. This application Apr. 17, 1970, Ser. No. 29,602
PILFERPROOF PACKAGE 3 Claims, 11 Drawing Figs.
0.8. CI 150/3, 150/66 Int. Cl 865d 17/20 Field of Search 150/3;
 References Cited UNITED STATES PATENTS 3,426,959 2/1969 Lemelson 229/66 X 3,473,589 10/1969 Gotz 150/3 Primary E.\'aminer Donald F. Norton Attorney-Hill, Sherman, Meroni, Gross and Simpson ABSTRACT: A pilferproof plastic bag having reclosable interlocking members and a tear ribbon which forms an access opening when pulled from the bag. The tear ribbon protrudes from the side of the bag for easy finger gripping.
A method of and means for making the bag by cutting and heat-sealing the sides to form completely sealed side edges having the tear ribbon protruding therefrom,
PILFERPROOF PACKAGE CROSS-REFERENCES TO RELATED APPLICATIONS This is a continuation-impart of my pending application Ser. No. 817,080, filed Apr. 17, I969 and entitled Pilferproof Package.
BACKGROUND OF THE INVENTION Field of the Invention In the copending application identified above I have disclosed a reclosable plastic bag having a removable tear ribbon for providing an access opening. The tear ribbon is also made of plastic and is formed and extends across the front wall of the bag. The plastic of which the tear ribbon is formed has a greater tear strength than does the front wall of the bag so that as it is pulled away it remains intact while the front wall of the bag immediately adjacent the tear ribbon rips to form a narrow jagged slit or access opening into the bag.
To enable the user of the bag to easily finger-grip the tear ribbon a portion thereof is separated from the bag wall to provide a loose finger-gripping end. In the assembled configuration or condition thereof the bag is completely closed and sealed while one end (or perhaps desirably both ends) of the tear ribbon protrudes away and hangs loosely from the face of the front wall of the bag.
While the bag disclosed in said earlier application is completely utilitarian I have determined that improvements are desirable in several respects concerned primarily with the manufacture of the bag.
Thus I have ascertained that the bag of my earlier applica' tion does not lend itself to the most economical bag-manufacturing techniques. Generally, the techniques which have been found most economical contemplate the formation of long or endless sections of bagmaking material, either in tubular form or else in the form of pairs of superimposed plastic sheets. In either event, the construction of the bag material is uniform throughout its length and is then cut into desired lengths and sealed along the cut edges to provide a series of uniform bags.
The bagmaking material of my earlier application is not, however, uniform along its length, assuming the length thereof is greater than that required for a single bag. Thus, the tear ribbon is not formed continuously on the bag front wall but instead is separated therefrom at predetermined lengths substantially equal to the length of an individual bag. This nonuniformity in bagmaking material substantially increases manufacturing difficulties and, concomitantly, manufacturing costs.
Among others, an object of the present invention is to provide a reclosable plastic bag with a tear ribbon which is as easy and convenient to use as that disclosed in my earlier application but which lends itself to more economical manufacturing techniques and processes.
SUMMARY OF THE INVENTION Having in mind the above as well as other objects which will become apparent from the following description, the invention may be summarized as comprising a reclosable plastic bag having a tear ribbon formed completely from one end to the other in a wall of the bag and having a finger-gripping end portion projecting from or beyond a heat-sealed side edge of the bag. The finger-gripping end of the tear ribbon directly overlies a pair of cars projecting from the front and back walls of the bag and the ears are sealed together at the distal end of the finger-gripping end as well as immediately adjacent the two sides thereof.
By virtue of the invention the tear ribbon, in the assembled condition of the bag. is bonded along its entire length to the front wall of the bag, thus substantially reducing the possibility of inadvertent rupture of the bag. Furthermore, the manufacture of the improved bag is substantially facilitated.
Other facets of the invention involve a method of and means for manufacturing the vimproved bag. The method may be summarized as comprising the steps of providing a longitudinal extent of bagmaking material including a pair of mating plastic sheets having formed on the inside faces thereof a pair of interlocking members extending in spaced-parallel relation to the longitudinal edges of the sheets and having formed on one of the sheets a plastic tear ribbon extending between and in spaced-parallel relation to the interlocking members and one of the longitudinal edges of the sheets, cutting the bagmaking material to provide a pair of transverse side edges, at least one of which includes an ear-shaped portion projecting laterally therefrom substantially equal in width to and including a finger-gripping portion of the tear ribbon, and heat-sealing the pair of transverse side edges and projection to form an individual bag. The corresponding means may be summarized as comprising apparatus for performing the foregoing method.
In addition to the foregoing, many other features, advantages and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheets of drawings in which preferred structural embodiments incorporating the principles of the present invention are shown by way of illustrative example only.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of a plastic bag or container constructed in accordance with the principles of the present invention;
FIG. 2 is an enlarged front elevational view of a corner of the bag;
FIG. 3 is similar to FIG. 2 but shows the finger-gripping portion of a tear ribbon partially dislocated from the bag;
FIG. 4 is an enlarged cross-sectional view of the upper portion of the bag taken substantially along lines IV-IV of FIG.
FIG. 4a is an enlarged cross-sectional view of the tear ribbon taken along line lVa-IVa of FIG. 2;
FIG. 5 is a plan view of an extrusion die useful in forming bag material and the construction of the bag shown in FIG. 1;
FIG. 6 is an enlarged fragmentary cross-sectional view taken along lines VI-VI of FIG. 5;
FIG. 7 is an isometric partial view of a cutting and sealing tool useful in making the bag shown in FIG. 1;
FIG. 7a is an enlarged view of a portion of a tool shown in FIG. 7;
FIG. 8 is a top plan view of bag material and the tool shown in FIG. 7 in the relative positions thereof as the tool cuts and seals the side edges of individual bags; and
FIG. 9 is an enlarged vertical sectional view taken along lines IX-IX of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1-4 disclose a plastic reclosable bag or container constructed in accordance with the principles of the present invention. The bag is indicated generally at reference numeral 10 and comprises a front wall 11 and a rear wall 12 which are interconnected along a top edge 13, a bottom edge I4 and opposite side edges 16 and 17.
The bag 10 is provided with means for selectively opening and closing the same for repeated use and to that end may be more particularly characterized as comprising fastening means indicated generally at reference numeral 18 and including a pair of cooperating elongated parallel transversely closable and releasable interlocking fastening members 19 and 20 formed respectively on inner adjacent faces 21 and 22 of the bag front and rear walls 11 and 12.
The interlocking members 19 and 20 are disposed in faceto-face relation in the assembled condition of the bag I0 and extend substantially the entire width of the bag in spacedparallel relation to the upper edge 13.
The specific configuration of the interlocking members I9 and 20 is the same as that disclosed in my earlier application mentioned hereinabove and is exemplary of many configurations known in the art with which they share the common characteristic of being closable as a result of the application of finger pressure along the length thereof and in a mutually facing or transverse direction. The members 19 and 20 are opened or separated by the application thereto of opposed transverse forces along the length thereof. Such fastening members, being well known in the prior art, do not require a more detailed description herein.
With the edges l3, 14, 16 and 17 a completely sealed interior chamber 23 is formed within the bag 10. To provide an access opening into the bag a tear ribbon or bead 24 is formed on the front wall 21 and extends in parallel relation to the interlocking members 19 and 20 and between said interlocking members and the top end or edge 13 of the bag 10.
The entire bag including the tear ribbon 24 is preferably made of plastic and the tear ribbon 24 is joined fast to the front wall 11 so that the two may be considered as being integral with one another. The tear strength of the ribbon 24, however, is substantially greater than that of the front wall 11, or at least that portion of the front wall 11 immediately adjacent to tear ribbon 24.
To that end the tear ribbon 24 may preferably be formed of a thermoplastic substance having characteristics different from those of the thermoplastic of which the remainder of the bag 10 is made. For example, the thermoplastic of which the ribbon 24 is constituted can have a greater tear strength than does the plastic of which the front wall 11 is made and also may have a somewhat higher or substantially higher extrusion temperature than that of the plastic which forms the remainder of the bag 10.
In the embodiment of the bag 10 shown in FIGS. 1-4 the tear ribbon 24 extends not only across the entire width of the bag 10 but also projects beyond the side edges 16 and 17 thereof. The front and rear walls 11 and 12 are also provided with ear-shaped portions 11a and 120 which project from the side edges 17 and 16 and conform substantially in size to end portions 24b and 24a of the tear ribbon 24 which project beyond the side edges 17 and 16.
The protruding portions 24a and 24b of the tear ribbon 24 may be described as finger-gripping end portions. ln opening the bag 10 the user grips one of the ends 240 or 24b and, holding the bag on both sides of the gripped end, pulls the tear ribbon 24 away from the front wall 11. FIGS. 1 and 3 illustrate the configuration of the tear ribbon 24 after it has been partially removed from the bag 10.
The finger-gripping ends 24b and 24a are superimposed on the ear-shaped portions 110 and 12a. in the formation of the bag 10 the ends of the front and rear walls 11 and 12 which form the side edges 16 and 17 are bonded together preferably by means of a heat seal. Upper and lower edges 26 and 27 of the ear-shaped protuberances 11a and 12a are also heatsealed together as is a far edge 28 thereof which coincides with the distal end of the tear ribbon 24. Thus, as shown in the enlarged sectional view shown in FIG. 4a, the ear-shaped portions lla or 120 extend just slightly above and below the tear ribbon 24 and are joined together along the edges 26 and 27 thereof. In some respects, therefore, each of the fingergripping ends 24b or 24a of the tear ribbon 24 and their corresponding ear-shaped portions 11a and 12a of the front and rear walls 11 and 12 may be considered a unitary protuberance, and in removing the tear strip 24 the entire multilayered protuberance is grasped between the fingers.
As the portion 24a is pulled from the bag 10, however, the ear-shaped portion 12a of the rear wall 12 becomes severed in a manner shown at reference numeral 29 in FIG. 3. Thus, the ear-shaped portion 12a is removed along with the fingergripping end 24a of the tear ribbon 24 as well as with the earshaped portion 11a. The severing of the rear wall may be achieved by a partial indentation seal placed in the rear wall 12 of the protrusion 120. To achieve this result the bag material is run across the sealing die 54 back to front, and as shown in FIG. 7a, while the bag is being formed by the sealing together of the bag edges by die 54, section 29 of the rear wall of the ear-shaped projection 12a is partially indented and weakened by sealing tool land segment 63a.
In order to completely open the bag 10 and to provide an access opening 30 along the entire width thereof the full length of the tear ribbon 24 is removed from the front wall 11. The longitudinal edges of the access opening 30 are. of course, left in somewhat jagged condition as indicated at reference numerals 31 and 32. It is not necessary that the tear ribbon 24 be provided with finger-gripping portions 24a and 24b at both ends thereof and the provision of two finger-gripping portions or only one is, therefore, largely one of choice.
Referring to the tear ribbon 24, it is noted that it resides form one end to the other largely in the general plane of the bag 10. The finger-gripping ends 240 and 24b thereof do not project away from the front wall 11 and thus are not in position to be inadvertently yet quite easily dislocated to form an opening or rupture in the front wall 11.
Furthermore, the bag 10 is uniform in cross-sectional configuration between the side edges 16 and 17 and consequently a number of the bags 10 can be conveniently formed from a length of bag material cut into shorter lengths and sealed to provide at side edges 16 and 17 of individual bags.
A length of bagmaking material may comprise two separate superimposed plastic sheets which form the front and rear walls 11 and 12 and which are heat-sealed along the transverse extremities thereof to provide the closed upper and lower edges 13 and 14. The facing surfaces of the plastic sheets have the interlocking members 20 and 19 formed respectively thereon and the tear ribbon 24 is formed on the sheet forming the front wall 11.
On the other hand, the bag material may comprise a continuous elongated tube which is cut into appropriate lengths to form individual bags. Such tubular material may be extruded from a die as indicated, for example, in FIGS. 5 and 6.
The die, which is indicated generally at reference numeral 33, may be more particularly characterized as comprising a die body 34 and a die plate 36 adjacent the die body 34. An annular groove 37, the cross-sectional width of which is related to the desired thickness of the walls 11 and 12, is formed in the die plate 36 and is interconnected by means of suitable passages 38 formed in the die body 34 to a source of heated, pressurized, extrudable thennoplastic having predetermined physical characteristics.
The interlocking members 19 and 20 are formed integrally with and are of the same thermoplastic material as the tubular sheet which forms the front and rear walls 11 and 12 by virtue of correspondingly shaped recesses 39 and 40 formed in the die plate 36 and in conducting relation with the flow passage The tear ribbon 24 may also be formed simultaneously in the same extrusion operation in which the tubular plastic sheet and the cooperating interlocking members 19 and 20 are fonned. To that end a complementarily shaped recess 41 is formed in the die plate 36 between recesses 39 and 40 and extends radially outwardly of the annular groove 37, in contrast with the inwardly directed recesses 39 and 40.
In the illustrated embodiment the recess 41 communicates with a flow passage 42 in the die body 34 which is connected to another source of extrudable plastic having physical characteristics different from those of which the plastic forming the tubular sheet and the interlocking members possess, at least insofar as tear strength is concerned. This second thermoplastic material issues from the recess or opening 41 onto an outer surface 43 of the tubular film forming the front wall 11 either before or after the plastic which forms the said wall has completely solidified or become finally rigid.
As discussed in my earlier application mentioned hereinabove, the plastic issuing from the recess 41 may be heated to a temperature above the plasticized temperature of which the tubular film is made and as the plasticized plastic ribbon 24 is directed onto the outer surface 43 the higher temperature of the ribbon, regardless of whether the tubular film has completely rigidified, will increase the temperature of the film which is engaged by the ribbon to a point where the thickness thereof will become decreased as indicated at reference numeral 44 in FIG. 4. Thus the higher the temperature to which the plastic ribbon 24 is heated, the more greatly reduced is the cross-sectional thickness of section 44, thereby providing a suitable degree of control over the tear force required remove the ribbon 24 as well as the physical characteristics of the jagged edges 31 and 32 of the access opening 30.
After the extrudate of the tubular film which forms the front and rear walls 11 and 12 as well as the extrudate of the tear ribbon 24 have become rigidified, the ribbon 24 is fully bonded to the front wall 11 and the two may therefore be considered as being integrally formed. The ribbon-forming extrudate may, of course, include a color additive to provide ready visual notice of the tear ribbon 24.
Regardless of whether the bag material comprises a length of circumferentially continuous tubular film or a pair of elongated super imposed plastic sheets bonded together at the upper and lower edges, the present invention contemplates an improved method of making plural bags therefrom and apparatus useful in the performance of the method.
Referring to FIGS. 8 and 9 there is disclosed somewhat schematically a length of bagmaking material indicated generally at reference numeral 46. The material 46 comprises an upper and lower sheet of plastic for forming the front and rear walls of a series of bags 10 and are therefore designated by reference numerals 11 and 12.
The bag material 46 may be transported on a conveyor or the like indicated at 47, which conveyor may be moved by suitable means in a rightward direction as the same is viewed in FIG. 8. The transverse extremities 13 and 14 of the bag material 46 are closed, either having been previously heat sealed, if the front and rear walls 11 and 12 are formed of separate sheets of plastic, or otherwise comprising integral portions of the front and rear walls ll and 12 if the bag material is formed of a length of a single circumferentially continuous extruded tubular film.
Disposed below the conveyor 47 is a stationary support member 48 and above the conveyor 47 and the bag material 46 thereon is a bag-forming tool indicated generally at reference numeral 49.
As shown diagrammatically at reference numeral 50 (FIG. 9) the tool 49 is supported for vertical movement toward and away from the backup support member 48, with which it is vertically aligned. The tool 49 may be more particularly characterized as comprising a tool body 51 having mounted on a lower wall 52 thereof a platelike member 53.
As shown in FIGS. 7 and 9, the member 53 has projecting away therefrom a knifelike land indicated generally at reference numeral 54 which comprises a first pair of spacedparallel longitudinal land segments 56 and 57 and a second pair indicated at reference numerals 58 and 59. Situated between the land segments 56 and 59 is an H-shaped land segment 60 having a pair of legs 61 and 62 extending transversely of the segments 56 to 59 and an interconnecting leg 63 which extends in parallel relation to the segments 56 to 59.
As shown in FIG. 9 the various segments and legs which comprise the land 54 are tapered to provide a narrow terminal end 64. Furthermore, the land segments are of sufficient length in a transverse cross-sectional direction to extend not only through both the front and rear walls 11 and 12 of the bag material 46 but also to accommodate between the plate 53 from which they extend and the bag material 46 a thin sheet member 66 preferably having both temperature and electrical insulating characteristics.
According to the principles of the present invention the conveyor 47 carries the extent of bag material 46 past the backup support 48 and the tool 49. At predetermined time intervals, the duration of which depend upon the desired lengths of the individual bags 10, the conveyor 47 stops and the tool 49, which theretofore is spaced from the conveyor 47 and the backup support 48, is moved downwardly to the position thereof shown in FIG. 9. Meanwhile the plate 53 and the land 54 have been heated to a temperature above the plasticizin temperature of the plastic of which the bag walls l1 and l and tear ribbon 24 are formed. Heating of the plate 53 and the land 54 may be accomplished by connecting thereto an electrical power source as suggested by the lead wires 67 and 68 shown in FIG. 9.
As the tool 49 moves downwardly the land 54 cuts through the sheets 11 and 12 as well as the tear ribbon 24 sealing them transversely together and then cutting through them so as to provide cutouts as indicated at reference numeral 69 in FIG. 8 corresponding in shape to the shape of the various segments of the land 54. The tool 49 is then moved upwardly and as the heated land 54 is withdrawn from the bag material. The material of which the conveyor 47 is made should be suffi ciently heat resistant to accommodate the increased temperature of the land 54. The sheet form insulating member 66 assists in confining the heating effect of the land segments on the plastic sheets 11 and 12 to those portions thereof in direct contact with or immediately adjacent the various segments of the land 54.
The cutouts 69 are wasted material but the expense involved in this waste is not excessive when considered vis-a-vis the savings involved in the manufacturing process of this invention. Furthermore, the cutout portions can, of course, be reprocessed in the formation of bag material, as will be understood by those skilled in the art.
The I-I-shaped land segment 60 is configured and arranges so as to provide the ear-shaped portions Ila and 12a of the front and back walls I] and I2 and to cut and heat-seal the edges of the ear-shaped portions along lines immediately adjacent the longitudinal edges 26 and 27 and the distal edge 28 of the fingergripping portion 240 and 24b of the tear ribbon 24. This feature, of course, enables the tear ribbon 24 to be properly severed fromthe front wall 11 as it is gripped and pulled away from the front wall 11 of the bag 10.
Although minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably come within the scope of my contribution to the art.
I claim as my invention:
1. A bag comprising a pair of superimposed plastic sheets closed along a top edge, a bottom edge and a pair of side edges,
a pair of elongated interlocking members formed on the inside faces of said sheets in spaced-parallel relation to said top edge, an elongated plastic tear ribbon formed on one of said sheets and extending between and in parallel relation to said top edge and said interlocking members,
said tear ribbon having one end projecting beyond one of said side edges and having a tear strength so much greater than that of the adjacent portions of said one sheet so as to form a narrow elongated access opening when pulled therefrom, and a pair of ears integral with said sheets projecting laterally beyond said one side edge and sealed together immediately adjacent the two sides and the distal end of the projecting portion of said tear ribbon.
2. The bag is defined in claim 1 wherein said ribbon is colored different from said sheets for providing ready identification thereof.
3. The bag as defined in claim I wherein an opposite end of said tear tear ribbon and another pair of ears project from the other of said side edges to enable the tear ribbon to be finger gripped from either side of said bag.