JPH0743906B2 - Tape car ledge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is directed to a tape cartridge in which a tape loading pocket is opened and closed by a shutter, and is improved with a locking means for holding the shutter at a predetermined position. It is a thing.

[Conventional technology]

In this type of tape cartridge, it has already been proposed to hold the shutter by locking means at both open and closed positions. For example, Japanese Patent Laid-Open No. 60-253076 proposed by the present applicant is one of them.

Here, as shown in FIG. 8 (a), the locking means 18 is composed of a locking claw 19 provided on the bottom wall 4 of the case, and engaging holes 20, 20 provided at two positions in front of and behind the shutter 10, respectively. By fitting the engaging element 23 at the tip of the claw 19 into the engaging hole 20, the shutter 10 is held immovable in both the open posture and the closed posture. The lock claw 19 is formed by co-molding with the lower case 1b in a cantilevered state extending from the case bottom wall 4, and the engaging element 23 is formed by its own elastic force.
The engagement posture of is maintained. A rocking restricting member 40 is provided above the engaging element 23 in order to restrict the amount of rocking of the lock pawl 19 inward of the case within the elastic deformation limit. This regulation member
40 was formed integrally with the upper case 1a.

[Problems to be solved by the invention]

In the conventional lock structure as described above, firstly, the lower case 1b is
There were the following problems with respect to the molding.

That is, as shown in FIG. 8 (b), the molding die of the lower case 1b has a lower surface of the case bottom wall 4 as a dividing surface, a lower side of which is a fixed side die A, and an upper side of which is a movable side die. Let B.
There, the molding space for the engagement element 23 that projects downward from the case bottom wall 4 is necessarily provided in the fixed-side mold A. In the case of such a die structure, the lock surface at the rear of the engaging element 23 at the time of mold release
In some cases, 29 is caught in the fixed side mold A, the lock claw 19 is deformed downward, and the engaging element 23 is broken from its continuous base end, resulting in defective molding.

Further, it is assumed that the front and rear lock surfaces 29 of the engaging element 23 are formed as downwardly sloping inclined surfaces, and the engaging element 23 is drawn into the engaging hole 20 when an external force in the front-rear direction acts on the shutter 10. Although there is a way of thinking that the locked state is maintained reliably, in this case, it is particularly necessary to form the front and rear lock surfaces 29 with an undercut mold, and it is expected that the above-mentioned molding defects will occur more frequently. It

[Object of the Invention]

An object of the present invention is to eliminate molding defects such as deformation and damage at the time of releasing the lock claw 19 or the engaging element 23, and improve productivity during molding of the lower case.

Another object of the present invention is to make it possible to utilize the projection 27 projecting from the upper portion of the lock claw 19 as a tape path defining member as required, so that the tape 2 can be assembled more easily and reliably. To do so.

[Means for solving problems]

The defect of the lock claw 19 at the time of releasing the mold is that the lock claw 19 has a cantilever structure and that the engaging element 23 and the fixed side mold A are
It is caused by a large mold release resistance.

Therefore, in the present invention, at the upper portion of the lock claw 19 and at the engagement element 23
The projection 27 is provided so as to project upward at a position corresponding to. In this case, the protrusion 27 can prevent the lock claw 19 from swinging downward and peeling from the movable mold B when the mold is released.

That is, the lock claw 19 formed integrally with the case bottom wall 4 by plastic molding is provided at the tip of the claw arm 22 extending in a cantilever manner from the case bottom wall 4 so as to project downward, and the locking hole on the shutter 10 side. A spring 33 that has an engaging member 23 that engages with and disengages from 20 and a protrusion 27 that projects upward from the tip of the pawl arm 22 and that biases the locking pawl 19 in the downward locking posture in the main body case 1. It is characterized by being installed.

[Action]

As shown in FIG. 2, in the state where the lower case 1b is released during molding, a moment that causes the lock claw 19 to swing downward due to the release resistance between the engagement element 23 and the stationary mold A. M works. However, a protrusion is formed on the top of the lock claw 19.
Since 27 is projected, the moment M is
It is received by the movable-side die B through and is canceled.
Therefore, it is possible to prevent the lock claw 19 from being deformed by being peeled off from the movable mold B, and to prevent the engaging element 23 from being broken from its continuous base end, so that the lock claw 19 can be correctly molded into a predetermined shape. can do.

〔The invention's effect〕

In the present invention, the moment M due to the release resistance that acts on the lock claw 19 and tries to peel it from the movable side mold B,
Since the protrusion 27 and the movable mold B are received by the mechanical engaging force, the locking claw 19 is deformed at the time of mold release, and the defective molding such as the damage of the engagement element 23 is eliminated, and the locking claw 19 is constantly operated. Can be molded into a regular shape, which can improve productivity during molding of the lower case 1b. Further, by setting the mechanical engagement force between the protrusion 27 and the movable mold B to be sufficient, the front and rear lock surfaces 29 of the engaging element 23 can be formed as inclined surfaces requiring undercut. This is also advantageous in that the locking claw 19 can be reliably prevented from accidentally coming off due to an external force acting on the shutter 10, and the reliability of the locking means 18 can be improved. Further, the lock claw 19 is elastically deformed in the vertical direction by the claw arm 22 that extends continuously in a cantilever manner from the bottom wall 4 of the case, but the elasticity of the claw arm 22 itself is limited in terms of material. However, the spring 33 mounted inside the main body case 1 always presses and urges the lock claw 19 in the downward lock posture. Therefore, the spring 33 compensates for the insufficient elasticity of the pawl arm 22, and the engagement element 23 of the lock pawl 19 is released by the shutter 10.
This is advantageous for surely engaging the engagement hole 20 of the shutter 10 and maintaining the locked state of the shutter 10. The spring 33 can also secondarily prevent the pawl arm 22 of the lock pawl 19 from being pushed upward to the unlocked state beyond its own elastic deformation limit.

Further, the protrusion 27 may be configured to exert a function of defining the tape path by projecting it largely upward. That is, the tape 2 is attached prior to the assembling of the upper case 1a.
And with the hub 3 assembled in the lower case 1b,
Since the taper 2 is guided and supported by the protrusion 27 to form a regular tape path, the upper case 1a can be assembled more easily and reliably than the conventional tape cartridge described at the beginning. That is, in the case of the conventional tape cartridge, when the hub 3 and the tape 2 are assembled in the lower case 1b prior to the assembling of the upper case 1a,
As shown in the figure, the tape 2 connects the tape guide 7 and the hub 3 at the shortest distance, and a part of the tape 2 passes above the engaging element 23. Before assembling the upper case 1a, the hub 3 is moved in the tape winding direction. It was necessary to rotate the tape 2 and move the tape 2 to a position outside the space above the engaging element 23 as shown by the imaginary line. If the upper case 1a is assembled without doing this, the tape 2 may be deformed by the rocking restricting member 40 provided on the upper case 1a, or the tape 2 may get inside the member 40 and cause a tape path defect. Because there was. However, the present invention can eliminate such a conventional problem.

[Embodiment 1] FIGS. 1 to 6 show a first embodiment in which the present invention is applied to an audio tape cartridge of a digital recording / reproducing system.

In FIGS. 3 and 4, reference numeral 1 is a main body case. The body case 1 is formed by screwing plastic upper and lower cases 1a and 1b together in a lid-fitting manner, and has hubs 3 and 3 on which the tape 2 is wound on the left and right sides inside. These hubs 3 and 3 are provided on the bottom wall 4 of the main body case 1 so that the left and right drive shaft insertion holes 5 and 5 are provided.
When it is on the upper side and rotates and is loaded on the deck, the drive shaft on the deck side fits and engages with each hub 3 through each insertion hole 5. A tape loading pocket 6 is largely recessed in the front center portion of the main body case 1, and the tape 2 is attached to one hub via tape guides 7 provided on the left and right front ends of the pocket 6. 3 is led out to the front surface of the case, traverses the pocket 6, and is wound up on the other hub 3.

The front and bottom of the pocket 6 are open. The front side of the pocket 6 is opened and closed by the front lid 9 for protecting the tape, and the bottom side is opened and closed by the shutter 10.

The front lid 9 is formed in a U-shape that is long in the left and right in a plan view, and a pivot 11 provided on the left and right connecting plates 9a is pivotally connected to the main body case 1 to open and close the front surface of the pocket 6. .
Incidentally, the front lid 9 is always biased by a spring member (not shown) so as to be freely closed.

In FIG. 3, the shutter 10 includes a main face plate 10a along the outer surface of the case bottom wall 4, left and right side walls 10b, 10b extending upward from both left and right edges of the main face plate 10a, and an inward direction continuous to the side walls 10b, 10b. It is a plastic molded product having protruding L-shaped cross-section retaining pieces 10c, 10c. Through holes 12, 12 corresponding to the drive shaft insertion holes 5, 5 on the left and right of the central portion of the main plate 10a
Have. As shown in Fig. 6, slits 13 are formed between the left and right mating surfaces of the upper and lower cases 1a and 1b.
By positioning the retaining pieces 10c, 10c inside the case via 13 and holding them in a sandwiched manner by the upper and lower cases 1a, 1b,
The shutter 10 slides back and forth along the bottom wall 4 of the case. In order to always keep the lower surface of the pocket 6 closed by the shutter 10 when not in use, a ferrule coil-shaped spring 14 is interposed between the lower case 1b and the shutter 10. One end of the spring 14 is a vertical wall 15 that divides the inside of the case from the pocket 6, and the other end of the spring 14 is provided near the front center edge of the inner surface of the shutter 10.
It is hung on 16 respectively.

Locking means 18 is provided between the case bottom wall 4 and the shutter 10 in order to hold the shutter 10 in both the open position and the closed position so that it cannot be displaced.

In FIG. 1 and FIG. 3, the locking means 18 includes a locking claw 19 and engaging holes 20 provided at two positions in front of and behind the shutter 10.
It consists of 20 and. A long hole 21 is formed in the front and rear of the case bottom wall 4 at a position near the rear end of the left end of the pocket 6, and a lock claw 19 is cantilevered forward from the rear end of the hole 21. The lock claw 19 is composed of a claw arm 22 that is elastically deformed vertically with the continuous base end side as a fixed point, and an engaging element 23 projecting downward at the tip (front end) of the claw arm 22.

A guide groove 24 running in the front-rear direction is formed on the lower surface side of the main surface plate 10a of the shutter 10 facing the lock claw 19. This guide groove
Reference numeral 24 is for guiding the lock releasing member 25 on the deck side, and the engaging holes 20 are provided at two positions near the front end and the rear end of the lock releasing member 25. The lock release member 25 on the deck side is guided from the front and contacts the rear end wall 24a of the guide groove 24 to move the shutter 10 relative to the main body case 1. The lower edge of the front lid 9 facing the front end of the guide groove 24 has a notch 9b for allowing the lock releasing member 25 to pass therethrough.

In the locking means 18 as described above, the present invention provides the engaging element 23.
It is characterized in that the lock claw 19 is prevented from swinging downward by a moment due to the release resistance of the lock claw 19.

Specifically, as shown in FIG. 1, a pin-shaped projection 27 is provided on the upper surface of the tip of the claw arm 22. The protrusion 27 is provided above the upper end position of the tape path in the main body case 1 and also serves as a tape path defining member for the tape 2. Especially,
When the hub 3 on the winding side is empty, the tape 2 is prevented from coming into contact with a structure such as a wall in the main body case 1.
The upper end side of the protrusion 27 is surrounded by a restriction boss 28 having a C-shaped cross section, which projects downward from the upper case 1a, with a small space therebetween.
The locking claw 19 can be swung upward only within the range in which the protrusion 27 contacts the inner surface of the regulation boss 28. That is, the regulation boss 28 regulates the free movement of the protrusion 27 so that the inward swing of the lock claw 19 does not exceed the elastic deformation limit.

When the protrusion 27 is formed on the upper part of the claw arm 22 as described above, when the lower case 1b is released from the mold, it is locked by the release resistance between the engaging element 23 and the fixed side mold A as shown in FIG. Even if the downward moment M acts on the claw 19, the protrusion 27 and the movable mold B
It is possible to completely prevent the moment M from being received by the mechanical engaging force with the lock claw 19 to be oscillated and deformed downward and to be peeled off from the movable mold B. Therefore, the engaging element
23 is forcibly separated from the fixed side mold A, and the lock claw 19
Along with that, it remains in the movable mold B. The protrusion 27 is pushed out of the movable mold B by the knockout pin P and released.

With the shutter 10 closing the pocket 6,
When an external force is applied to the shutter 10 toward the rear of the case,
The claw arm 22 receives a buckling load and tries to bend and deform. At this time, when the claw arm 22 is deformed in a convex arc shape, the engaging element 23 is tilted forward, the front locking surface 29 is pushed by the engaging hole 20 and an upward component force is generated, and the engaging element 35 is engaged. It is pushed out of the hole 20. In order to prevent this, it is necessary to constantly deform the claw arm 22 into a concave arc shape. As a means for this, in the illustrated example, a buckling arm 22a, which is slightly thinner than the claw arm 22 and is diagonally downward, is formed at the base end portion of the claw arm 22 extending from the case bottom wall 4, and the claw arm 22 is subjected to a buckling load. When acting, the buckling arm 22a is deformed prior to the pawl arm 22, and the pawl arm 22 can be surely deformed into a concave arc shape.
It should be noted that the lock surfaces 29, 30 for unlocking are formed at the lower ends of the lock surfaces 29 in front of and behind the engaging elements 23.

In FIG. 4, reference numeral 32 is a brake member mounted in the main body case 1. The brake member 32 is slidable back and forth, and is urged to slide rearward of the case by a spring 33, and when not in use (in a normal state), the brake claws are extended from the left and right rear ends.
32a abuts and engages with the engaging portions 3a provided on the outer circumferences of the upper ends of the left and right hubs 3 to prevent the hubs 3 from rotating. When loaded on the deck, the brake member 32 is moved to the front side of the case in conjunction with the upward opening rotation of the front lid 9, whereby the brake is released.

In FIGS. 4 to 6, the spring 33 is formed of a leaf spring, and a mounting portion having an inverted L-shaped cross section is formed substantially in the center thereof.
A spring arm 35, which has 34 and biases the brake member 32 from the left and right side ends of the mounting portion 34 toward the rear of the case, is extended obliquely rearward. The spring 33 is also used to assist the downward biasing force of the lock claw 19. An auxiliary spring arm 36 extends obliquely downward from the upper wall of the mounting portion 34 toward the inside of the regulation boss 28. The auxiliary spring arm 36 urges the protrusion 27 downward to urge the lock pawl 19 to move. The spring pressure is compensated by urging the lock posture downward. The mounting portion 34 includes an inner wall plate 37 that supports the brake member 32 from below and an upper case 1a.
It is held by and. The inner wall plate 37 is continuously extended from the transparent window plate 38, and an appropriate portion is welded and fixed to the inner surface of the upper case 1a.

[Second Embodiment] FIG. 7 shows a second embodiment of the present invention. This is the engaging element 23
The front and rear lock surfaces 29 are inclined surfaces that need to be undercut and are formed in the shape of an upper recess. In this case, since it is necessary to forcibly disengage the engaging element 23 from the fixed side mold A, the engagement force between the protrusion 27 and the movable side mold B can be made sufficiently large by, for example, forming the protrusion 27 to be slightly larger. Keep it.

In addition to the above embodiment, the present invention also contemplates that the locking claw 19 is formed in advance so that the tip side of the claw arm 22 projects downward from the lower surface of the case bottom wall 4 in the free state. . Further, the locking means 18 may be provided on both the left and right sides of the pocket 6 and is not limited to the above embodiment.

Further, the tape path defining member and the swinging restricting member may be formed separately from the protrusion 27. That is, the protrusion 27 of the present invention may be one that at least selectively achieves one of the above objects.

[Brief description of drawings]

1 to 6 show a first embodiment of a tape cartridge according to the present invention. FIG. 1 shows a shutter locking means, which is a sectional view taken along the line AA in FIG. 4, and FIG. Sectional view of the molding die showing the release state of the lock claw, Fig. 3 is an exploded perspective view showing the main body case and the shutter separately,
4 is an overall plan view showing the internal structure of the tape cartridge, FIG. 5 is a sectional view taken along the line BB in FIG. 4, and FIG. 6 is a sectional view taken along the line CC in FIG. FIG. 7 is a vertical cross-sectional side view of essential parts showing a second embodiment of the present invention. 8 (a) and (b) and FIG. 9 show a conventional example, FIG. 8 (a) is a vertical cross-sectional side view of an essential part showing an outline of a locking means, and FIG. 8 (b) is a lock claw. FIG. 9 is a cross-sectional view of the molding die showing a released state, and FIG. 9 is a plan view of a main part. 1 ... Main body case, 4 ... Case bottom wall, 6 ... Pocket, 10 ... Shutter, 18 ... Locking means, 19 ... Locking claw, 20 ... Engaging hole, 23 ... Engaging element, 27 ... … Protrusions.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeo Motori 1-188, Tora, Ibaraki City, Osaka Prefecture Hitachi Maxell Co., Ltd. (56) References: 61-121580 (JP, U)

Claims (3)

[Claims] 1. A tape loading pocket 6 is opened on the front surface of a main body case 1 and has a shutter 10 for opening and closing the pocket 6 so that the shutter 10 can slide back and forth on the outer surface of a case bottom wall 4. Is mounted on the case bottom wall 4 and the shutter 10, and has locking means 18 for holding the shutter 10 at a predetermined position such that the shutter 10 cannot be opened, closed, and moved, and the locking means 18 is integrated with the case bottom wall 4. The lock claw 19 includes a lock claw 19 formed by plastic molding and an engagement hole 20 formed in the shutter 10. The lock claw 19 includes a claw arm 22 cantilevered from the case bottom wall 4 and a claw. The main body case 1 has an engaging member 23 protruding downward from the tip of the arm 22 and engaging and disengaging with the engaging hole 20, and a protrusion 27 protruding upward from the tip of the claw arm 22. A spring 33 is installed to press and urge the locking pawl 19 in the downward locking posture. Tape cartridges, characterized in that there. 2. The tape cartridge according to claim 1, wherein the protrusion 27 functions to prevent the downward swing of the lock claw 19 against the release resistance of the engagement element 23 during molding. . 3. The tape cartridge according to claim 1, wherein the projection 27 also serves as a tape path defining member.