JP2951009B2 - How to adjust the clamping force of the tape clamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette,
More specifically, the present invention relates to an improvement of a clamp member used in a reel hub for winding a magnetic tape.

[0002]

2. Description of the Related Art Clamp members used for fixing the start or end of a magnetic tape wound on a reel hub to the reel hub generally include an outer drum portion and an inner belt portion for providing elasticity. And a leg connecting the two parts. It has been disclosed in the Japanese Patent Application No. 57-70629 of the present applicant that the thickness of both sides of the inner belt portion at both ends is made thinner than the central portion so as to be approximately convex. The main application was to avoid the problem of tape damage that can occur during tape clamping. However, in an actual tape cassette, the reel hub has various diameters depending on the tape length or the tape thickness and the like, so that an optimum clamping force corresponding to each reel hub is required.

[0003]

The problem to be solved is that it is difficult to form a tape clamp having an optimum clamping force for reel hubs of various diameters as described above, which makes the design of a mold difficult. This leads to an increase in costs associated with the manufacture of the mold.

[0004]

According to the present invention, there is provided a method for adjusting a clamping force of a tape clamp for engaging and locking a recess of a reel hub to lock a tape end. Manufacturing the tape clamp in which a ridge is provided on a part of the inner belt portion of the clamp member along the circumferential direction; (b) measuring the clamping force; and (c) changing the width dimension of the ridge. A method for adjusting the clamping force of the clamping material is provided.

[0005] The method of the present invention includes the step of providing a ridge particularly on the inner belt portion of the clamp member,
1) A large groove corresponding to a mold may be formed to form the ridge and to change the width thereof, and only the concave groove is formed without adjusting other parts of the mold. Since the adjustment is sufficient, the processing of the mold is facilitated. 2) Regardless of the shape accuracy, it is possible to optimize the clamping force for reel hubs of various diameters.

[0006] The present invention also provides a step in which abutment portions of a pair of molding dies are provided with a groove portion corresponding to a ridge provided on a part of the inner belt portion of the tape clamp;
The method according to claim 1, further comprising: performing steps (a) and (b), adjusting the width or depth of the groove portion in step (c), and then manufacturing another tape clamp. Also provided is a method of adjusting the clamping force of the tape clamp according to 1 above, thereby achieving simplification of the design of a mold for manufacturing a tape clamp having various clamping forces.

[0007]

1 to 5 illustrate a tape clamp 12 having a ridge 10 formed by the method of the present invention. The ridge 10 is formed linearly along the circumferential direction of the reel hub 16 shown in FIG. 5 at a substantially central portion of the lower band portion 14 of the tape clamp 12 as shown in FIG. By changing the width m of the ridge 10, it is possible to easily optimize the clamping force of the tape clamp attached to the reel hub having various diameters.

FIG. 4 exemplifies a state in which a tape clamp having the ridge 10 is formed inside the first and second dies 18 and 20. FIG. 4 is a cross-sectional view of a main part of a molding die having the ridge 10, and it should be noted that a portion not shown is configured in a similar shape to a mold known in the art. The dies 18, 20 have an inner belt part 14 of the tape clamp and pieces 19, 21 for molding the opposing surfaces of the outer drum part 13. Each of these pieces is adapted to be abutted when the mold is attached, and the groove portion 22 forming the ridge 10 is formed along the abutted portion. In this example, the ridge 10 is
It can be formed by notching a part of one mold (the second mold 20 in the figure) and forming a groove portion 22 with the other mold.

[0009]

Accordingly, by appropriately adjusting the width of the groove portion 22, it is possible to easily form a tape clamp having an optimum clamping force for each of the reel hubs having the respective diameters as described above. In actual molding, the clamping force is designed to be low, injection molding is conducted on a trial basis, the clamping force is measured, and then the groove is cut and re-molded to form a tape clamp for the specified clamping force. It can be a mold that has been adjusted to fit.

[Brief description of the drawings]

FIG. 1 is a side view of a tape clamp having a ridge formed according to the present invention.

FIG. 2 is a sectional view of FIG. 1 taken along line aa.

FIG. 3 is a plan view of FIG. 2 viewed from an arrow direction.

FIG. 4 is a cross-sectional view illustrating a state in which a tape clamp is formed using upper and lower dies.

FIG. 5 is a perspective view illustrating a use state of the tape clamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Ridge 12 Tape clamp 13 Outer drum part 14 Inner band part 16 Reel hub 18 1st mold 20 2nd mold 22 Groove part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 23/087 508 B29C 33/42 B29C 45/26

Claims (2)

(57) [Claims] 1. A method for adjusting a clamping force of a tape clamp, wherein a tape end is locked by fitting and locking into a recess of a reel hub, the method comprising: (a) adjusting the tape clamp along a circumferential direction of the reel hub; Manufacturing the tape clamp provided with a ridge on a part of the inner belt portion, (b) measuring the clamping force, and (c) then manufacturing another tape clamp having a changed width dimension of the ridge. A method of adjusting the clamping force of the tape clamp, thereby including. 2. A step in which a groove portion corresponding to a ridge provided on a part of an inner belt portion of a tape clamp is provided at an abutting portion of a pair of molding dies, and a step (a) and a step (a). The tape clamp according to claim 1, further comprising a step of manufacturing another tape clamp after performing b) and adjusting the width or depth of the groove portion in the step (c). How to adjust the clamping force of