JPH0286563A - Tape reel - Google Patents

Abstract

PURPOSE:To avoid any dimensional error in molding as well as to make assembly performable in a highly accurate manner by installing a clearance of such size as in consideration of an error in this mold shrinkage in advance, in space between the top of a hub edge and the underside of an upper flange being opposed to it. CONSTITUTION:A tape reel consists of a plastic reel hub 45 solidly molded with a lower reel flange 44 and a plastic upper reel flange 43 being fitted in this reel hub 45. A recess part functioning as height reference planes 48, 50 for the upper reel flange 43 is formed in an upper end of this reel hub 45, and those of upper reel flange 43 and reel hub 45 are melted by heat and unified with the surface side of the reel hub 45 of the upper reel flange 43 as one body after being fitted in this recess part. At this time, a clearance is formed in space between an edge 45a forming this recess part and a surface of the upper reel flange 43 being opposed to this edge 45a. With this clearance (d), any dimensional error in molding is avoidable.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape reel used in, for example, a VTR (video tape recorder, video tape player), etc., and an object thereof is to attach a reel member obtained by molding to both upper and lower flanges. The object of the present invention is to maintain the parallelism of the two parts in a good state, and to be able to join them with high precision even if there are dimensional errors due to molding.

First, in order to facilitate understanding of the present invention, a tape cassette for a VTR to which the present invention can be applied will be explained using FIGS. 1 to 3.

In FIGS. 1 and 2, (1) shows the whole tape cassette with a rectangular planar outline, and (2) shows its casing, which is the upper half of a synthetic resin molded product such as ABS resin. (3) and a lower half (4), and a pay-out reel (20) and a take-up reel (21), which will be described later, are arranged in parallel in the longitudinal direction inside the half. (5) is an opening/closing lid body made of a similar resin molded product pivotally attached to the front side of the case body (2), and this lid body (5) projects inwardly with symmetrical pivots (6a) and (6b). It has left and right side plates (7a) and (7b) to be installed,
It is elastically biased in the closing direction (arrow a indicates the opening direction) as shown in the figure. (8) (8a, 8b) are the lid body (5) from both sides of the upper half (3) with the dividing line of the upper half (3) and lower half (4) as the border on the left and right sides of the case (2).
(9) indicates a guide groove formed near the rear of the bottom of the lower half (4). - It is a guide means when mounting the cassette (1) on the cartridge holder, and is used for both X-direction insertion and Y-direction insertion. In addition, the cassette (1) of this example has an upper half (
3) A circular transparent part (10) is provided on the right side of the upper surface, and a shallow recess (11) with, for example, a rectangular outline is formed on the left side adjacent to it, and a name plate (12) (
Labels) are attached. (13) is a mask at the center of the transparent part.

On the other hand, the feed reel (20) and the take-up reel (21) each have a hub (24) (24a, 24b) having a hub hole (24) (24a, 24b).
23) (23a23b), upper flange (22) (
22a, 22b) and a ratchet wheel-shaped lower flange (22a, 22b) having, for example, square teeth (26) at a constant pitch on the circumference.
25) (25a, 25b), and the tape (T) is moved from the feed reel (20) to the guide pin (27a, 25b).
) and (28a) to the inside of the front plate of the lid (5), and reaches the take-up reel (21) through guide pins (27b) and (28b). (33) (33a, 3
3b) is the square tooth (2) of the lower flange (25) of each reel.
These ratchet pieces (33) are pivoted by pins (33') and interlock with the lid body (5) via their respective pivots (6). When the lid body (5) is closed, each end (locking end) of the ratchet piece (33) engages with the tooth groove of the square tooth (26), and the tape payout direction ( Feeding reel 2 clockwise 1 take-up reel: counterclockwise)
It is designed to prevent rotation. Note that each ratchet piece (33) is biased toward the square tooth (26) via a winding spring. Further, (30) is a partition plate, (31) is a protection plate for the tape (T) when the cassette is not in use with the lid (5) closed, and (32) is a tape slack prevention member. (34) is the long lever for the cover earth, and the pin (3
5), and when the lid is closed, the claw piece (36) of the lock lever engages with the square locking hole (13) of the lid body (5), and the lid body is locked, and the cassette (1) is placed on the VTR side. When attached to the holder from the X or Y direction, the release iron on the holder side enters the notch (14) and locks the lock lever (3).
4) Press the pressing part (37) at the free end to release the lock lever (
34).

(38) is a reel holding means which is used as a reel holding device and is made of, for example, a substantially cross-shaped plate spring, and steel balls (39) are fitted into the center of each upper flange (22a) and (22b) at the arm end. is holding down.

As shown in FIG. 3, the reels (20) and (21) described above usually consist of an upstream small member (40A) having an upper flange (22), a lower flange (25), and a hub (23).
) and the lower reel member (40B) integrally formed with the molded upper reel member (40^) are respectively molded with synthetic resin.
) and the reference surface (23') at the upper end of the hub of the downward small member (40B) are joined together.

Conventionally, such reel parts have been assembled by applying adhesive to the surfaces to be joined, that is, in this case, the surface that also serves as the reference surface, or by abutting the surfaces to be joined and then applying ultrasonic welding. One possible method is to use a method to join the abutting surfaces.

However, in this case, the surfaces that come into contact with each other serve as the reference surface for bonding, so adhesive may be interposed on this surface, or
Another drawback is that it is difficult to achieve parallelism between the upper and lower flanges of the reel when these surfaces are melted and joined. Poor parallelism between the upper and lower flanges can cause jitter, etc.
This parallelism requires precision. In addition, the plastic material in -g produces whiskers due to temperature differences after molding, resulting in so-called dimensional errors, making it difficult to obtain assembly accuracy. Furthermore, the upper reel member (40A) and the lower reel member (40A)
B) is made of different materials, i.e., when polyacecool resin is used for the lower reel member, which requires wear resistance, as in the upper part, and acrylic/styrene resin is used for the upper reel member, which requires transparency. It is difficult to select an adhesive that is compatible with both materials, and ultrasonic welding is difficult because the melting points of the two materials are different. That is, when an ultrasonic welder is used, due to the difference in materials, only the side of the upper small member and the lower reel member having a lower melting temperature melts, which tends to result in incomplete adhesion.

In view of the above points, the present invention strictly maintains the parallelism of the upper and lower flanges without affecting each reference plane even in reel members made of different materials, and can be assembled accurately even if there are dimensional errors due to molding. It provides a tape reel that can be obtained.

That is, the present invention consists of a synthetic resin reel hub that is integrally molded with a lower reel flange, and a synthetic resin upper reel flange that is fitted to this reel hub. A concave portion that acts as a surface is formed, and a convex portion that fits into the concave portion is formed on the reel hub surface side of the upper reel flange, and after these concave portions and convex portions are fitted, the upper reel flange and reel hub are heated. The reel is integrated by melting and is characterized by a gap being formed between the edge forming the recess and the surface of the upper reel flange facing the edge.

The present invention will be described in detail below with reference to FIGS. 4 and 5.

In the same figure, (41) shows an up-wing member having an upper flange (43), and (42) shows a down-wing member having a lower flange (44) and a hub (45) integrally. Formed by molding synthetic resin. The descending reel member (42) has a hub hole (46) in which the reel holder on the apparatus main body side is fitted into the hub (45), and a reel holder attached to the upper surface of the cassette case at the upper end of the hub. It has a spherical top (47) that is pressed directly by the free end of the leaf spring that is the means. It should be noted that various means can be considered as means for pressing the reel using a leaf spring, such as pressing a steel ball fitted into the center of the upper flange as shown in Fig. 2, and this example shows one such means. It's nothing more than that.

In the present invention, as shown in FIG. 5A, the hub (45)
A reference plane (48) is formed on the upper end surface, which is parallel to the annular lower flange (44) with the apex (47) as the center, and, for example, from above this reference plane (48), a plurality of objects can be attached integrally with the reference plane (48). A projecting piece (49) is provided. Also, the upper reel member (41
), the reference plane (4) on the down-wing member (42) side is also
Similarly, a reference surface (50) parallel to the upper flange (43) is formed in the portion facing the protruding piece (4).
Engagement holes (5) through which the protrusions can be inserted are provided at positions corresponding to (9), respectively.
Form 1) for multiple addresses. In this case, the center top of the hub (
47) and the upper surface of the upper flange (43) are made substantially on the same plane, and the melted and expanded portion of the protrusion (49), which will be described later, is on the top (4).
7) and the reference surface (48) on the hub side is formed into a groove in order to be positioned below the upper surface of the upper flange (43), and the reference surface (50) of the upper reel member is fitted into this groove. It is formed into a convex surface. Also, the reference surface on the hub side (48
) serves as a reference for determining the spacing between the upper and lower flanges, so when the upper reel member (41) is overlapped with the upper end surface of the hub (45), the upper surface of the edge (45a) of the hub (45) is A small distance d is formed between this and the corresponding lower surface of the upper flange (43). In addition, if a transparent window is formed in a part of the top plate of the cassette case that houses the reel and the tape wound around the reel can be seen through the window, the upper flange (43) of the reel is also transparent. It is necessary to use expensive materials. Possible materials suitable for this purpose include acrylic styrene resin or polycarbonate resin. On the other hand, the material forming the hub (45) is such that the hub top (47) comes into contact with the temporary spring that is the pressing means on the case side, and that it prevents slipping when fitting the reel holder into the hub hole (46). Due to the need for better performance, it is possible to use a resin material that is wear resistant and has a small coefficient of friction. Possible materials suitable for this purpose include polyacetal resin or a mixed resin of polycarbonate resin and fluororesin.

Then, the upper reel member (41) and the lower wing member (42)
First, the upper reel member (
41) - abut the reference surfaces (50) and (48) against the hub upper end surface of the wing member (42), and each protrusion (
49) are inserted into the corresponding engagement holes (51) and placed (the chain line shows the state before the up-wing member (41) is placed). After that, as shown in FIG. 5B, the engagement hole (51
) The tip (49a) of the protruding piece (49) facing the upper reel member (41) is heated and melted to be welded to the upper reel member (41).

According to the present invention, when the upper reel member (41) and the lower reel member (42) are integrated, both members (41) and (42)
) The reference surfaces (50) and (48) formed on both members (41) and (42) can be accurately The reference surfaces (50) and (48) are maintained so that accurate dimensions of the tool can be assembled. In particular, the parallelism between the upper and lower flanges (43) and (44) can be achieved extremely accurately. As mentioned above, synthetic resin materials generally produce whiskers due to temperature differences after molding, but there is a gap between the upper surface of the edge (45a) of the hub (45) and the lower surface of the upper flange (43) facing therebetween. By providing the gap d with a dimension that takes this mold sinkage error into consideration, it is possible to escape the dimensional error in molding, and high-precision assembly can be achieved.

Furthermore, even when connecting the reel members (41) and (42), it is only necessary to melt the projection (49) formed on the member (42) on one side, so each reel member (41) and (42) need only be melted.
42) It is possible to create a good reel without being restricted in selecting a resin material suitable for the function.

Incidentally, in the above description, a reel applied to a tape cassette for a VTR has been described, but the present invention can also be applied to other tape reels.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a tape cassette for a VTR to which the present invention can be applied, FIG. 2 is a cross-sectional view thereof, FIG. 3 is a sectional view showing the assembled state of a conventional reel, and FIG. Cross-sectional views showing one embodiment of the reel according to the present invention, FIGS. 5A and B
2A and 2B are cross-sectional views of main parts showing assembled states, respectively. (41) is the upper reel member, (42) is the lower reel member, (
43) is the upper flange, (44) is the lower flange, (45)
is a hub, (48) and (50) are reference surfaces, (49) is a protrusion, and (51) is an engagement hole.

Claims (1)

[Claims] It consists of a synthetic resin reel hub integrally molded with a lower reel flange, and a synthetic resin upper reel flange fitted to the reel hub, and the upper end surface of the reel hub acts as a height reference plane for the upper reel flange. A concave portion is formed, and a convex portion that fits into the concave portion is formed on the reel hub surface side of the upper reel flange, and after the concave portion and the convex portion are fitted, the upper reel flange and the reel hub are integrated by heat melting. 1. A tape reel characterized in that a gap is formed between an edge forming the recess and a surface of the upper reel flange facing the edge.