US2687978A - Synthetic plastic film tape - Google Patents

Description

Aug. 31, .1954 c. w. VOGT SYNTHETIC PLASTIC FILM TAPE Filed Aug. 9. 1951 INVENTOR. CLARENCE W. VOGT WW 7 0M 61's H ORNEYS Patented Aug. 31, 1954 TS PATENT OFFICE 3 Claims.

The present invention relates to tapes formed of synthetic plastic film and embodies an improved form of tape having means formed therein to facilitate transverse tearing or rupturing thereof. The relatively great resistance to tear in directions across the grain of tapes of this character is well known and, in many uses, a characteristic of great value. However, in some instances, this property becomes a disadvantage and renders the tape unsuitable for use.

Examples of tapes of this type are tapes formed of cellulose derivatives (e. g. regenerated cellulose, and cellulose esters and ethers) and of synthetic resins such as polyvinyl resins, polyethylene and polyacrylic esters. They are now widely used, and their properties well known. In accordance with the present invention, it is proposed to provide tapes of the above character with structural characteristics such that, without impairing their tensile strength, they may be easily torn by exerting suitable stresses thereon at one or both edges thereof.

To realize the foregoing object, such synthetic plastic film tapes are formed along one or both edges thereof with a plurality of relatively closely spaced slits or notches having angular apices providing weakened points at which tearing will take place with the application of relatively little tearing stress.

In order that the invention may be better understood, it will be described in connection with one specific use thereof and, to that end, reference will be made to the accompanying drawings, wherein Figure 1 is a partial plan view showing the manner in which a plurality of tapes are formed from a single web in accordance with the present invention;

Figure 2 is a view similar to Figure 1, showing a modified tape formation also constructed in accordance with the present invention;

Figure 3 is an enlarged segmental view in detail showing one edge only of a tape formed in accordance with the present invention;

Figure 4 is a view similar to Figure 1, showing a modified form of the invention and wherein weakened portions are formed in the tape of a different shape and character than those illustrated in Figures 1 and 2;

Figure 5 is a partial plan view of the elements in Figure 4 after they have been partially separated; 1

Figure 6 is a perspective view showing a plurality of commodities connected together by means of tapes formed in accordance with the present invention;

Figure 7 is a perspective view similar to Figure 6, but showing the manner in which the top pair of commodities is removed from the assembled group illustrated in Figure 6; and

Figure 8 is a perspective view showing a modified way in which commodities may be assembled by means of the tape structure of the present invention.

Referring to the above drawings, a synthetic plastic web is illustrated generally at Hi, this web being formed of any of the substances hereinabove mentioned and. having the characteristic of great toughness against tearing or shearing stresses across the grain. The specific manner in which the length of tape is manufactured forms no part of the present invention, the characteristics of the present invention being imparted to the tape whether it be of a single piece of desired length and width or whether it be formed of a web of a desired length but of a width which is a multiple of a final width desired of the tape. If the material from which the final tape is to be made is wider than the desired final width of the tape, it may be formed as illustrated in Figures 1, 2, 4, and 5.

In Figure 1, for example, the entire width of the web l0 may be severed into three separate tapes H, 12, and [3, the tapes [I and [2 being formed of the material along the marginal edge of the web 10, while the tape 12 is formed of the material of the intermediate portion of the web [0.

The tapes H, I2, and I3 are formed from the web I9 by means of longitudinally extending cuts l4 and I5 and angularly extending cuts 16 in tape ll, l1 and [8 in tape 12, and L9 in tape l3. It will be observed that, in the form of the invention illustrated in Figure 1, the cuts 56 parallel each other as do all of the cuts ll, l8, and I9, respectively, and that each out It lies in the same plane as a corresponding cut ll, while each cut l8 lies in the same plane as a corresponding cut [9.

It will also be seen that all of the cuts l6, l1, l8, and 19 lie at angles'to the respective cuts [4 and I5, and also to lines extending transversely of the tapes. Another important aspect of the invention resides in the fact that the angularity of the respective cuts IE, IT, IS, and I9, as well as their length, is such that, when projected upon the respective cuts 15 and 16, they will at least reach the point where the next adjacent out intersects the cuts 14 and 15. This structure insures that there will always be a weakened edge portion available to facilitate tearing along the edges of the tapes containing the cuts it, H, I8.

and i5} regardless of where the tearing stresses are applied. In this fashion the tape l l is formed, along one edge only, with a multiplicity of closely adjacent cuts which serve to provide a great number of weakened portions along the edge of the tape 5 l.

Referring to the form of the invention illustrated in Figure 2, a wide web 213 is illustrated as being formed into four final tapes 2 l, 22, 23, and 24 by means of longitudinal cuts 25, 26, and 21. Angular cuts 28, 29, 30, 3|, 32, and 33 are formed in herringbone formation, as illustrated in Figure 2, of such angularity and length that the projection of each cut upon the edge of the tape in which it is formed extends a distance at least as great as the intersection of the next adjacent out with that edge. For example, referring to Figure 2, it will be seen that the end 3 of one of the cuts 3!) lies in substantially the same horizontal plane as the point 35 which is the intersection of the next lower cut 38 with the cut or edge 26.

Figure 3 is an enlarged partial view of the cuts formed in any of the tapes ll, I2, 2 l, 22, or 23 and illustrates, more clearly, the manner in which the inner ends of the cuts overlap (in a longitudinal direction) the intersection of the next adjacent lower cut with the edge of the cut.

In Figures 4 and 5, a slightly modified form of the invention is illustrated wherein a relatively wide web 36 is formed into three tapes 3'!, 3B, and 39 by means of cuts 40, 4|, 42, and 43 which are formed as pinking cuts, the extremities of which are continued beyond the intersections of their angular sides. The cuts formed, as illustrated in Figures 4 and 5, insure an edge formation that is weakened substantially against tearing or shearing stresses. Not only do the notches formed by the pinking cut provide points of weakness at which tearing readily occurs, but the extensions of such cuts in the manner illustrated in the drawings further assures points of weakness at the inner extremities of each of the cuts. Here again it will be observed that the inner extremities of each of the cuts overlaps (in a longitudinal direction) the edge extremity of the next most adjacent and lower cut, as illustrated in Figures 4 and 5.

Tapes formed with the weakened edge portions hereinabove described are particularly useful in assembling articles and commodities, as illustrated in Figures 6, '7, and 8. In Figures 6 and 7, for example, a plurality of commodities Hi, 45, 46, 47, 48 and 49 are assembled together in pairs and in stacked relationship. End tapes 5-9 and 5! serve to connect together each of the respective pairs 44, 45, 46, ll, and 48, 19. In the stacked relationship illustrated in Figure 6, side tapes 52, 53 serve to maintain all of the pairs effectively as a rigid unit. If desired, transverse strips of any suitable translucent adhesive material 5 3 may be provided on the outer surface of one or more of the respective pairs 44, :25, 45, i! and 48, 49 in order to anchor the respective pairs more effectively in the assembled position illustrated in Figure 6.

To remove one or more of the pairs from the unit illustrated in Figure 6, for example the upper pair, it is only necessary to twist such pair in either direction (counter-clockwise as illustrated in Figure '7) to cause the tapes 52 and 53 to tear at the meeting edges of the pair to be separated and, if adhesive 54 is utilized, to rupture such adhesive. The weakened portions in the tapes 52, 53 formed by the cuts as hereinabove described permits separation of the pairs as above described with great ease, whereas if the tapes 52, 53 had not been formed with the weakened portions, it would be extremely difficult to separate the pairs by the twisting operation above described.

After one or more pairs have been separated from the multiple unit, individual elements may be separated from each other by splitting apart the bonds formed by the tapes 5i], 5!. This is readily done by swinging the articles away from each other about an axis coincidental with the adjacent corner edges of two adjacent articles. Here again the slits formed in the tapes facilitate such separation.

In the form shown in Figure 8, the tapes of the present invention are utilized to secure a plurality of commodities 55, 56, 57, and 58 together, end tapes 59 and 60 being utilized for this purpose in a manner similar to the tapes 5!] and 5!, while a single bottom tape BI is provided to hold the articles in assembled relationship and against movement with respect to each other in parallel planes. The bottom tape 8! provides strength against forces exerted upon the top of the unit that would otherwise tend to separate the same by tearing the end tapes in the planes of the meeting edges of the articles. The articles assembled into the unitary structure of Figure 8 are separated from each other by twisting the articles with respect to each other in the meeting planes of the articles to be separated in order to sever the side tape 6! adjacent the plane of the contiguous sides of the articles being separated.

From the foregoing it will be seen that a tape of synthetic plastic film material has been provided having the well known tensile strength inherent in such material, but at the same time having suitably formed weakened portions along one or more edges to facilitate tearing of the tape at a multiplicity of points.

While the invention has been described with specific reference to the accompanying drawings, it is not to be limited save as defined in the appended claims.

I claim:

1. A tape formed of a synthetic plastic film material having relatively high tear strength and being formed along at least one edge thereof with a multiplicity of parallel slits each being inclined at an acute angle to the edge and extending inwardly therefrom, the angularity and length of the slits being such that the projection of the inner end of each slit upon the adjacent edge of the tape at least reaches the intersection of an adjacent slit with such edge to form weakened points along the length of the tape at which the resistance to tear of the tape is substantially reduced.

2. A tape formed of a synthetic plastic film material having relatively high tear strength and being formed along at least one edge thereof with a multiplicity of notches formed with inwardly directed angular apices, and parallel slits extending inwardly from the inwardly directed apices, each slit being in alignment with one of the edges of the notches to form points at which the resist ance to tear of the tape is substantially reduced.

3. A tape formed of a plastic film material having relatively high tear strength and being formed along at least one edge thereof with a multiplicity of notches formed with inwardly directed angular apices, and parallel slits extending inwardly from said inwardly directed apices, each slit being in alignment with one of the edges of the notches to form points at which the resistance to tear of the tape is substantially reduced, the

5 6 angularity and length of the slits being such that Number Name Date the projection of the inner end of each slit upon 2,049,030 Strauss July 28, 1936 the adjacent edge of the tape at least reaches the 2,159,355 Goetze May 23, 1939 intersection of an adjacent slit with such edge. 2,229,982 Mansur et a1 Jan. 28, 1941 5 2,240,274 Wade Apr. 29, 1941 References Cited in the file of this patent 2,353,330 Ruzicka, Jan, 30, 1945 UNITED STATES PATENTS 2,508, 55 BIOWn May 23, 1950 2,584,074 Wilkins Jan. 29, 1952 Number Name Date 2,047,982 Page July 21, 1936 10

Claims (1)

1. A TAPE FORMED OF A SYNTHETIC PLASTIC FILM MATERIAL HAVING RELATIVELY HIGH TEAR STRENGTH AND BEING FORMED ALONG AT LEAST ONE EDGE THEREOF WITH A MULTIPLICITY OF PARALLEL SLITS EACH BEING INCLINED AT AN ACUTE ANGLE TO THE EDGE AND EXTENDING INWARDLY THEREFROM, THE ANGULARITY AND LENGTH OF THE SLITS BEING SUCH THAT THE PROJECTION OF THE INNER END OF EACH SLIT UPON THE ADJACENT EDGE OF THE TAPE AT LEAST REACHES THE INTERSECTION OF AN ADJACENT SLIT WITH SUCH EDGE TO FORM WEAKENED POINTS ALONG THE LENGTH OF THE TAPE AT WHICH THE RESISTANCE TO TEAR OF THE TAPE IS SUBSTANTIALLY REDUCED.

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