JP2527868Y2 - Cassette and cassette spring - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates generally to springs used to align tape reels. More particularly, the present invention relates to a plastic plate spring for applying an axial alignment pressure to a tape reel of a video cassette.

[0002]

2. Description of the Related Art Magnetic tape cartridges or cassettes (eg, video cassettes) are well known and widely used. The magnetic tape in these cassettes is wound on a reel rotatably mounted inside the housing. This type of cassette typically includes a spring mounted on the housing and engaging a wear button on the axis of the reel. The spring applies axial pressure to the reel to ensure proper engagement with the drive spindle of the cassette drive. This spring also prevents the reel from being pushed around when the cassette is transported.

There are two prominent formats for storing and playing back video data in a video cassette recorder (VCR). This is the VHS format and the beta format. VHS video cassettes and beta video cassettes made by different manufacturers must conform to specifications established to ensure compatibility with VCRs. One of these specifications for VHS video cassettes is that the reel pressure springs are 280g and 380g when the ends of the springs are pushed down a distance of 0.080 inches (2.03mm) from the spring mounting surface (the inner wall of the cassette). Need to provide a load or pressure between

[0004] One spring used in the videocassette type is a stainless steel strip having a central portion fixed to the inner surface of the upper housing wall.
The two free ends of the strip are bent into an arc that opens upwards away from the housing wall. The free end or spring member projects cantilevered from the central portion of the steel strip and engages the hub portion of the reel near its outer end to bias the reel away from the upper housing wall.

[0005] There remains a need for improved springs for use in such video cassettes.
All such springs must be able to meet the required specifications at economically acceptable prices. Since videocassettes are produced in very large quantities, small changes in component costs can have a significant effect on overall production costs. Thus, any improvement that results in a small reduction in component costs (such as this reel spring) can also result in a significant improvement in the economic viability of the product.

[0006]

SUMMARY OF THE INVENTION The present invention is a relatively inexpensive spring for applying pressure between a first member and a second member. The spring has an airfoil shape and includes a central mounting portion configured to mount to the first member. A pressure part is attached to this attachment part by a connection part.
The pressure portion is shaped to engage the second member. Extending from the connection between the mounting portion and the pressure portion is an upwardly inclined spring portion of a pair of airfoils. The mounting portion of the spring is secured to the first member such that the spring portion engages the first member at a non-perpendicular angle. The upwardly inclined spring portion resiliently urges the pressure portion away from the first member and into engagement with the second member.

In one preferred embodiment of the spring, the first member is the upper portion of the videocassette case and the second member is the wear button portion of the reel for holding the magnetic tape. These reels are rotatably mounted inside the bottom portion of the video cassette. The spring is secured to the upper portion of the cassette case so that when the top portion of the cassette case is mated with the bottom portion, a desired amount of pressure contact is applied to the hub portion of the reel in the axial direction. This arrangement of springs allows the use of thin materials of low elastic modulus as spring materials. More specifically, the present invention enables the use of plastic as a material for such a video cassette spring.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Throughout the drawings, the use of related terms such as left, right, up, down, etc. is used herein for reference only and is not intended to limit the structure of the disclosed device. Although the up and down directions are described with reference to FIG. 2, the arrangement of the illustrated video cassette follows the usual manner in a video cassette player. As shown in FIG. 2, the drive spindle is inserted into the video cassette from the bottom as usual.

The assembled video cassette is shown in FIG. The cassette 10 includes a case or housing 1.
4, a pair of reels 16 and 18, and a spring 12
(See FIG. 2). The housing 14 is defined by a top or first housing member 20 and a second or bottom housing member 22. Tape reel 1
6 and 18 are rotatably mounted inside the bottom housing member 22. A pair of holes 24 and 26 extend through the bottom housing member 14 to provide a video cassette player /
Recorder splined drive spindles 25 and 27
(See FIG. 3) engage and rotate the reels 16 and 18. Tape reels 16 and 18 are used to store magnetic tape 28. As magnetic tape 28 is advanced between reels 16 and 18, information is transmitted to and from tape 28 in a known manner.

The hemispherical wear buttons 30 and 32 extend from the upper surfaces of the reels 16 and 18, respectively, and act as bearing members. Wear buttons 30 and 32 provide a small, smooth contact area between reels 16, 18 and spring 12. Minimizing the contact area between the spring 12 and the rotating reels 16, 18 reduces the frictional effect between these components and therefore increases the useful life of the video cassette.

The spring 12 is typically attached to the interior surface of the upper housing member 20 by rivet-type fasteners 34 and 36, but other types of fasteners (eg, adhesives) can also be used. When the upper member 20 and the bottom member 22 are assembled to form a completed video cassette housing 14, the opposing free ends of the springs 12 engage the wear buttons 30 and 32 to provide a downward biasing force (away from the upper member 20). ) Is applied to each of the reels 16 and 18.

The cassette 10 is a video cassette player /
When inserted into a recorder (not shown), drive spindles 25 and 27 pass through holes 24 and 26 and engage the hubs of reels 16 and 18 to lift the reels away from the inner surface of bottom housing member 22. The spring 12 exerts a downward force on the reel so that the reel is firmly positioned on each drive spindle and engaged with the spindle. The spring 12 also prevents damage to the tape 28 by resisting rotation or axial movement of the reels 16 and 18 as the cassette 10 is handed and transported.

One preferred embodiment of the spring 12 is illustrated in FIGS. 2, 3, 4, 5, 6 and 7. The spring 12 is wing-shaped, as shown in FIG. 4, and is preferably formed from an elastic plastic material such as polycarbonate. Structurally, the spring 12 has a pair of elongated connecting members or bottom portions 38 and 39 which are joined at their inner ends by a central mounting portion 40. The bottom members 38 and 39 and the central mounting portion 40 are aligned and form a longitudinal "backbone" for the spring 12. Pressure end portions 46 and 48 have bottom portions 38 and 39
Are provided at respective free ends facing each other. As shown in FIG. 5 (an end view of the spring 12), the side or wing spring portions 50 and 52 are separated from each fold portion 54 and 56 by a respective bottom portion 38.
And 39 to form an elongated groove along the spine of the spring. The shape of this groove is truncated "V" in cross section, i.e., V-shaped with a flat bottom surface as best seen in FIGS. The holes 55 and 57 in the central mounting part 40 allow the spring 12 to
4 is provided for attachment to the upper member 20.

The structure of the spring 12 is symmetric. As can be seen in FIG. 4, the spring 12 has a first upper half 58 and a second lower half 60, the second lower half 60 being a mirror image of the first upper half 58. It is in. Similarly, each side of spring 12 is a mirror image. For illustrative purposes, the spring 12 has a right side 62 and a left side 64 as shown in FIG. Because of its symmetry, the spring 12 can be identified by describing one side of one half of the spring. For example, the right side 74 of the second lower half 60 is defined along one edge by a fold 56 and upright sides defined along its free edges by free edges 66, 68, 70 and 72. 52. In its main part, the upright side surface 52 has a substantially triangular shape. Free edges 66 and 72 are crease 56
Extend substantially parallel to and are spaced apart from each other. Free edge 72 extends generally along central mounting portion 40 of spring 12. The free edges 68 and 70 extend at an angle away from the fold 56 and meet at an outer rounded free edge 73 to define a generally triangular shape of a major portion of the upright side 52. The free edge 70 of the upright side 52 thus defines a first tapered portion 74, which is angled away from the fold 56 as it approaches the rounded free edge 73. Similarly, free edge 68 defines a second tapered portion 76, which is
Fold 56 as it approaches the rounded free edge 73
Angled away from In the second lower half 60, the pressure portion 48 is defined in part by the free edge 66 of the bottom portion 39 and the outer end portion. FIG.
As shown in FIGS. 6 and 6, a major portion of the upright side 52 is angled upwardly from the bottom portion 39 to form a fold 54
Symmetrical (mirror image) upright sides 50 facing along
(Having a main triangular portion). The first upper half 58 is similarly formed having two major portions that extend upward at an angle to each fold and bottom portion 38.

The preferred method of constructing the spring 12 is (a) injection molding and (b) stamping the blank from a plastic sheet, followed by creating upwardly sloping sides 50 and 52 relative to the bent bottom portions 38, 39 and 40. And that. Injection molding has the advantage of producing lower cost parts when large quantities are required, whereas punching and bending allows for the use of lower cost production equipment and when less parts are needed. Costs can be reduced.

When the die-cut forming method is used, the spring 12 preferably stamps the blank from a plastic sheet and subsequently forms and forms the bottom portions 38, 39 and 4.
Sides 50 and 52 are created which are inclined upwards with respect to zero. One preferred embodiment of the material used to form the spring 12 has the dimensions represented by the letters AL in FIG. 7, where A = 3.937 inches (100
mm), B = 0.250 inch (6.3 mm), C = 0.6
25 inches (15.8 mm), D = 1.656 inches (4
1.5mm), E = 1.761 inches (43.4mm), F
= 0.414 inch (10.4 mm), G = 45 degrees, H =
0.156 inch (3.95 mm), I = 0.250 inch (6.3 mm), J = 0.50 inch (12.6 mm),
K = 1.00 inch (25.4 mm). After molding, each upright side faces 30-70, as indicated by the letter L in FIG.
It is aligned with its base at a free rise angle in the range of degrees. This type of spring molded or constructed from 0.009 inch (0.25 mm) thick polycarbonate material has been found to meet the required specifications for a VHS video cassette spring. The spring formed in this way is therefore upright 5
The opposing upstanding main portions of 0 and 52 provide a resistive bias when pressure is applied to its free end in an attempt to flatten the wing.

Other suitable materials for the spring 12 include plastics that have sufficient heat resistance to allow the spring 12 to retain its elastic properties after being exposed to the environment prescribed by the specification. In.
These environmental requirements are at 160 ° F (72 ° C) for 72 hours.
0 ° C). More specifically, those polymeric materials having a glass transition temperature above this value are believed to meet this requirement. In addition, the spring material is required to have a low cost manufacturing method, in particular, a forming method following die punching from a sheet material or an alternative injection molding method. When a die-cutting and forming method is used, it is useful, but not necessary, to achieve a forming action at a sufficiently elevated temperature to soften the material.

As an alternative to plastic, the spring 12 can be formed from metal, with the thickness and other dimensions of the spring providing a sufficiently low resilience. In all cases, the spring material is VH
It must meet the cost constraints afforded by mass production in the competitive market for S-video cassettes.

The spring 12 is shown in FIGS. 4 to 6 in a free standing state prior to being mounted in the video cassette housing. The shape of the spring 12 when fixed to the housing 14 is shown in FIGS.
To 7 are shown. Spring 12 is cassette 1
0, which is fixed to the top member 20 of the
(See FIG. 5) is pressed flat against the inner surface 78 of the top member 20. Therefore, the open side of the groove is pressed against the inner surface 78 of the top member 20. Spring 12 is secured by rivets through holes 55 and 57 or by any other suitable fastening method. The free ends of the rising sides 50 and 52 of the spring 12 are also
0 and engages each bottom portion 38 and 39 with the inner surface 78 of the top member 20 as shown in FIGS.
Acts to bias away from The bottom portions 38 and 39 become further away from the inner surface 78 of the top member 20 as the winged upright side of the spring 12 extends further away from the central mounting portion 40. The free edges of the upright sides 50 and 52 engage the top member 20, the upright sides 50 and 52 deform (see FIGS. 8 to 10) and bend at the folds 54 and 56, and the bottom sections 38 and 39 and the pressure section 46. And 48 (at the outer free end of the spring) are biased away from the inner surface 78 of the top member 20, as seen in FIG. When the videocassette is placed in the VCR, pressure portions 46 and 48 transmit this bias from spring 12 to wear buttons 30 and 32 on reels 16 and 18, thereby directing them to their respective drive spindles. Energize. The pressure portions 46 and 48 have a relatively narrow shape and engage the wear buttons 30 and 32 without interfering with the reels 16 and 18.

[0020] Typically, the top member 20 is formed from a low cost plastic and therefore does not have a high degree of resistance to wear. It is highly desirable to eliminate such damage because attrition will cause plastic shavings or other debris to adhere to the recording tape or to the tape drive or read / write mechanism. The free edges of the spring 12, which move or rub back and forward across the inner surface 78 of the top member when the videocassette is used, will cause such wear. To eliminate the detrimental effects described above, the free edge of the spring 12 engaging the top member 20 is provided with a rounded edge shape.

Several examples of rounded edge shapes for the free edge of the spring are shown schematically in FIGS. As can be seen in FIG.
Free edges 80 and 82 are bent inward (inwardly toward a U-shaped groove formed in the spring) to form a gently curved edge for the upright side. Another edge configuration is shown in FIG. 14, where the free edges 84 and 86 of the spring 12B are bent outward (away from each other) to form a gently curved edge for each of the upstanding sides. I am trying to do it. A third configuration is shown in FIG. 15, where the free edges 88 and 90 of the spring 12C are formed on enlarged or beaded edges to assume a blunt or rounded edge shape for the upright side. I have. In addition, other known safeguards against wear can be employed.
For example, if the spring is formed by injection molding, the parting line must not be placed in a position that contacts the inner surface 78 of the top member 20. If the spring was formed by stamping and subsequently thermoforming a blank from sheet material, the thermoformed bend would place the rounded side of the stamped portion in contact with the top housing 20. In order to prevent the burr on the spring from contacting the top member 20. It is, of course, desirable to have the free end of the spring bend as large as possible to reduce the likelihood of the inner surface 78 of the top member 20 being worn. These rounded edge shapes are useful for any of the spring shapes described herein.

Another embodiment of the spring of the present invention is shown by spring 12 'and is illustrated in FIGS. Spring 12 'is also a one-piece sheet of plastic formed in elongated U-shaped groove bottom portions 38' and 39 'and a central mounting portion 40' therebetween. The outer free ends of the bottom portions 38 'and 39' have pressure portions 46 'and 4
8 ', these pressure portions also adapted to engage the hub of the video cassette tape reel. The upright or spring portions 50 'and 52' have bottom portions 38 'and 39'.
And central mounting portion 40 'along folds 54' and 56 '
And are linked to Hole 55 'in central mounting portion 40'
And 57 'are provided for attaching the spring 12' to the top member as described above. Upright sides 50 'and 52'
Is different from the spring 12 of FIG. 4, especially along the free edge of the spring. The pressure portions 46 'and 48' do not have free edges extending parallel to the folds like the spring 12. These edges are tapered toward the tip, as best seen in FIG.

As with the spring 12, the spring 12
Is a symmetric structure. Thus, a description of one side of one half of the spring 12 'is sufficient to define all the shapes of the upright sides. The upright side 52 'of the lower right half of the spring 12' has one side edge defined by a fold 56 'and has a free edge defined by free edges 68', 70 'and 72'. ing. The free edge 72 'is spaced from and parallel to the fold 56' of the central mounting portion 40 'of the spring 12'. Adjacent to the mounting portion 40 'is a first tapered portion 74' and a free edge 70 '
Are tapered so as to gradually move away from the fold 56 '. The free tapered edge 70 'extends further away from the fold 56' at a point closer to the pressure section 46 'than at a point closer to the mounting section 40'. The second tapered portion 7 proximate to the first tapered portion 74 '
6 ', the free edge 68' is tapered in the direction toward the fold 56 ', this taper being more pronounced. Except for its wing-shaped upright side shape, the spring 12 'is the same as the spring 12 in material, operation, mounting to a video cassette, and the like.

Another embodiment of the present invention is shown in FIGS. 19, 20 and 21 as a spring 12 ". The spring 12" also has a longitudinal central spine formed from opposing bottom portions 38 "and 39". And a central mounting portion 40 "therebetween. One piece of sheet plastic formed in an elongated U-shaped groove. Bottom portions 38" and 39 ".
At its free outer end there are pressure portions 46 "and 48" which are arranged to engage the axial hub of the tape reel of the video cassette. The upstanding side or spring portions 50 "and 52" are connected to the bottom portions 38 "and 39" and the central mounting portion 40 "via folds 54" and 56 ".

Holes 55 "and 57" in center mounting portion 40 "
Is provided for mounting the spring 12 ". The shape of the upstanding sides 50" and 52 "of the spring 12" is shown in FIG.
9, 20, and 21 differ from springs 12 and 12 '. Spring 12 "is also symmetrical, but upstanding sides 50" and 52 "are generally formed as two opposing panels rather than two pairs of opposing wings (such as springs 12 and 12 '). These two panels have the same shape in a mirror image relationship.
For example, the upright side 52 "of the right half of the spring 12" has one side edge defined by a fold 56 "and the free end defined by free edges 66", 68 ", 75" and 77 ". The free edge 66 "is spaced apart from and substantially parallel to the fold 56". The free edge 68 "is free edge 66" and the fold 56 as seen in FIGS. ″ And away from it. Free edge 7
3 "is spaced from and parallel to the fold 56" and extends from the outermost edge of the free edge 68 "to the outermost edge of the free edge 75" (the central mounting portion of the longitudinal length of the spring 12 "). (Almost along 40 "). The free end 75 "is angled from the outermost edge toward a fold 56" and a fold 56 "spaced apart and substantially parallel to the fold 56". The free edge of the upright side 52 "thus extends farther from the fold 56" at the portion closer to the mounting portion 40 "than at the portion closer to the pressure portions 46" and 48 ". Spring 1
2 "is the same as the spring 12 in material, operation, mounting on a video cassette, and the like.

The above several embodiments have two symmetrical parts 5
8 includes a spring having 8 and 60
Since the spring action of the spring acts independently of the action of the portion 60, a spring having only one pressure portion, e.g., 48, is formed by simply forming only one half of the spring 12, e.g., the portion 60. It will be appreciated that it can be done. Such a spring
It can be used in magnetic recording cassettes having only one reel, such as some types of data cartridges, or in cassettes where it is desired that each reel has its own separately made spring.

If each of the two reels has its own separately made spring, however, these springs are arranged so that the mounting parts of the springs overlap, and one mounting means is used for both springs. To be able to For example, if the mounting was made with rivets through the holes in the mounting portions of the springs, the holes in one spring would be aligned with the holes in the other spring, and the same mounting rivet would pass through both springs. Advantageously.

[0028]

In each of these embodiments, the spring of the present invention obtains its spring force by pressing the opposing wing panels against the inner surface of the video cassette cartridge without relying on cantilevered action. . Thus, the biasing force applied to the tape reel hub is more uniform and more stable than conventional springs. Furthermore, the spring of the present invention can be manufactured at a lower cost than previously conceived video cassette tape reel springs, and is easily mounted on the housing. Because of the use of low cost materials, the springs of the present invention meet the specific cost requirements of the prior art. Since videocassettes are produced in large quantities, the cost savings of any part of the cassette will be significant relative to the cost of the overall videocassette assembly.

[Brief description of the drawings]

FIG. 1 is a perspective view of a lower side of a VHS video cassette.

FIG. 2 is an exploded view of the VHS video cassette with the upper portion of the housing separated from the bottom portion.

FIG. 3 is a sectional view of the VHS video cassette taken along line 3-3 in FIG. 2;

FIG. 4 is a top view of a preferred embodiment of the spring of the present invention.

FIG. 5 is an end view showing a state where the spring shown in FIG. 4 is not attached.

FIG. 6 is a perspective view of the spring shown in FIGS. 4 and 5;

FIG. 7 is a top view of the blank sheet cut to form the spring shown in FIGS. 4, 5 and 6;

FIG. 8 is a sectional view of the attached spring of FIG. 2 taken along the line 8-8 in FIG.

9 is a cross-sectional view of the attached spring of FIG. 2, taken along the line 9-9 in FIG.

FIG. 10 shows the attached spring of FIG. 2;
It is sectional drawing which follows the 10 line.

FIG. 11 is a cut-away cross-section through the center of the reel axis, showing the spring in a compressed state.

FIG. 12 shows the spring in an uncompressed state;
FIG. 4 is a cross-sectional view of the reel, which is taken along the axis of the reel.

FIG. 13 is a cross-sectional view of one alternative embodiment of an attached spring wing as shown in FIGS. 4, 5 and 6;

FIG. 14 is a cross-sectional view of one further embodiment of one of the attached spring wings as shown in FIGS. 4, 5 and 6;

FIG. 15 is a cross-sectional view of yet another embodiment of one of the attached spring wings as shown in FIGS. 4, 5 and 6;

FIG. 16 is a top view of another embodiment of the spring of the present invention.

FIG. 17 is an end view in a state where the spring shown in FIG. 16 is not attached.

FIG. 18 is a perspective view of the spring shown in FIGS. 16 and 17;

FIG. 19 is a top view of still another embodiment of the spring of the present invention.

FIG. 20 is an end view of the spring shown in FIG. 19;

FIG. 21 is a perspective view of the spring shown in FIGS. 19 and 20;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Video cassette 12 ... Spring 14 ... Case 16 ... Reel 18 ... Reel 28 ... Tape 38 ... Connection part 39 ... Connection part 40 ... Mounting part 46 ... Pressure part 48 ... Pressure part 50 ... Spring part 52 ... Spring part 54 ... Crease 56 ... fold 66 ... free edge 68 ... free edge 70 ... free edge 72 ... free edge 78 ... case inner surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Dale Sheader Trefson Minnesota 55144-1000, United States, St. Paul, 3M Center (no address)

Claims (8)

(57) [Scope of request for utility model registration] 1. A case, a pair of reels rotatably mounted inside the case, and an integral one-piece spring made of an elastic sheet-like material for applying pressure between the case and the reel. A cassette, wherein the spring is mounted on an inner surface of the case;
A pair of elongated connecting portions extending toward the reel from opposite sides of the mounting portion, and a pair of elongated connecting portions each connected to one of the connecting portions facing the mounting portion and engaging one of the reels; A pressure portion and two pairs of spring sides, each pair of spring sides extending from one opposite side of the connecting portion to form an elongated groove between the mounting portion and the spring side, A pair of spring sides having free edges formed to engage the inner surface of the case and resiliently press the pressure portion away from the case and into engagement with the reel. Containing cassette. 2. A spring for applying pressure between opposing first and second members, the spring including an elongated longitudinal groove having lateral upright sides, a mounting portion, and a free end. And a mounting portion of the spring member is fixed to the first member, and the open side of the groove is pressed against the first member to deform the upright side surface so that the pressure is increased. Means for biasing the portion to engage within the second member. 3. A spring for applying pressure between a first member and a second member, the spring including a formed piece of sheet-like material, wherein the sheet-like material is applied to the first member. A mounting portion configured to be mounted, a pressure portion spaced from the mounting portion and configured to engage a second member, and a connecting portion connecting the pressure portion to the mounting portion; A pair of upright spring portions extending from a connection between the mounting portion and the pressure portion; and a mounting portion of the piece of material secured to the first member and the spring portion engaging the first member at a non-perpendicular angle. And a fastener that resiliently presses the pressure portion away from the first member and into engagement with the second member. 4. The spring according to claim 3, wherein the upright spring portions extend apart from each other within a range of 30 to 70 degrees from the vertical. 5. The upright spring portion includes a free edge extending from the pressure portion to the mounting portion, the free edge engaging the first member and moving the pressure portion away from the first member to a second member.
4. The spring according to claim 3, wherein the spring is formed so as to be elastically pressed to engage with the member. 6. A pair of folds wherein the spring portion is defined by the intersection of the upstanding spring portion and the connecting portion and extends from the pressure portion to the mounting portion, and a mounting portion having a free edge extending an equal distance from an adjacent fold. A first tapered portion having a free edge tapering away in a first direction away from an adjacent fold; a first tapered portion proximate to the mounting portion; and a first edge having a free edge tapering in a second direction towards the adjacent fold. 6. The spring of claim 5, including a second tapered portion proximate the tapered portion, and a pressure portion proximate the second tapered portion, the free edge extending an equal distance from the adjacent fold. . 7. A pair of folds wherein the spring portion is defined by the intersection of the upright spring portion and the connecting portion and extends from the pressure portion to the mounting portion; and a mounting portion having a free edge extending an equal distance from an adjacent fold; A second tapered portion having a free edge tapering in a second direction toward an adjacent fold, and a second tapered portion proximate to the attachment portion and a second tapered portion having a free edge extending an equal distance from the adjacent fold; 6. A spring as claimed in claim 5, including a pressure portion. 8. A spring portion defined by the intersection of the upstanding spring portion and the connecting portion and a pair of folds extending from the pressure portion to the mounting portion, a mounting portion having a free edge extending an equal distance from an adjacent fold; A first tapered portion, the free edge tapering in a first direction away from the adjacent fold, a first tapered portion proximate the mounting portion; and a first taper, the free edge tapering in a second direction toward the adjacent fold. A second tapered portion proximate to the tapered portion.