JPH0536670U - Magnetic tape cassette - Google Patents

Abstract

(57) [Summary] [Purpose] A cassette half with a structure that can be ultrasonically welded to the trapezoidal part on the front side of the cassette is provided, and mechanical stability of the trapezoidal part and prevention of verticality of the guide pin are prevented. At the same time, we aim to improve productivity and product reliability. The present invention relates to a magnetic tape cassette having a trapezoidal portion in the center of the front surface, in which a pair of tape winding bodies in which a magnetic tape is rotatably wound is housed in a case body composed of a pair of upper and lower cassette halves. is there. Further, at least one tubular portion 8 having the bottom plate 9 flush with the surface of the top plate portion 5 of the cassette half is formed in the trapezoidal portion, and the tubular portion 8 is formed into the side plate portion 6. It is also fixed by welding.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic tape cassette in which a case body is composed of an assembly of upper and lower cassette halves used in an audio tape recorder, and more particularly, a front opening having a front opening into which a magnetic head or the like can enter in the center of the front surface of the cassette. The present invention relates to a magnetic tape cassette having a structure in which cassette halves are welded.

[0002]

[Prior Art]

 Conventionally, a magnetic tape cassette incorporating a pair of tape winding bodies is generally used for audio and the like. Figure 3 shows the basic structure of this audio magnetic tape cassette. Note that FIG. 3 is a perspective view showing a combined state of the upper and lower cassette halves. As is well known, the magnetic tape cassette 1 shown in FIG. 3 has a pair of upper and lower cassette halves 2a and 2b integrally fixed by screws 3 and a pair of hubs 4 each having a magnetic tape T wound therein. The structure is rotatably supported by the insertion holes 4a and 4b.

Although the cassette halves 2a and 2b have some protrusions, ribs, and partition walls inside the flat plate-shaped top plate portion 5, basically, the top plate portion 5 and the top plate portion 5 The side plate portion 6 formed at the edge of the portion 5 has a substantially U-shaped cross section. In addition, the top plate portion 5 is formed with a trapezoidal portion 7 having an opening portion at the front portion of the cassette and having a trapezoidal planar shape. In particular, in recent years, magnetic tapes have been improved in quality for recording and reproduction with higher performance, and along with this, there has been an increasing demand for higher quality case bodies.

However, in the structure in which the upper and lower cassette halves 2a and 2b are fastened with screws 3, a gap is formed on the mating surfaces of the upper and lower cassette halves due to deformation of the cassette halves 2a and 2b and loosening of the screws 3. In some cases, dust easily enters the magnetic tape cassette and adheres to the built-in magnetic tape T to deteriorate recording / reproducing characteristics. Normally, the cassette halves 2a and 2b are trapezoidal portions 7. In addition, the cassette halves 2a and 2b are firmly fixed by the tightening force of the five screws 3 at the four corners.

[0005]

[Problems to be solved by the device]

 On the other hand, in recent years, the low price of the magnetic tape cassette has become a major factor in its commercial value. In such a situation, for example, fixing the upper and lower cassette halves 2a and 2b with screws requires parts such as screws and man-hours, and it is difficult to say that productivity is good. Ultrasonic welding of the end surface of the side plate portion 6 has been performed. However, since the trapezoidal portion 7 has a so-called cassette thickness, which is formed to be higher than the top plate portion 5 in the surface height, is formed in this portion, the side plate portion 6 is welded to the outer periphery of the cassette. Can not weld to the same degree. That is, since the heights of the trapezoidal portion 7 and the top plate portion 5 are different, the distance between the welding head and the welding portion is different, so that the degree of melting of the resin varies. Further, it is also proposed that the tooth portion (not shown) of the opening is welded, but since this tooth portion is thinner than the side plate portion 6, it is the same as the welding degree of the side plate portion 6. Not only is it difficult to achieve, but it is also prone to deformation due to welding due to its thin wall. Since the back side of the tooth portion is the running path of the magnetic tape, when the tooth portion is deformed, there is a problem that the tape running property is impaired.

Further, it is said that it is preferable that the tooth portions are configured so that upper and lower ones do not come into contact with each other. This is because, if the upper and lower end surfaces of the tooth portion are in contact with each other and the dimensional accuracy is not extremely high, this contact causes the trapezoidal portion 7 to be deformed so as to increase its thickness. Or, the tooth portion is deformed in either the front or rear direction of the cassette. This deformation of the trapezoidal portion affects the verticality of the guide pin formed inside the trapezoidal portion, and has a very serious result that directly adversely affects the tape running property in the area close to the magnetic head. There was a problem that caused it.

For these reasons, in the conventional cassette half welding type magnetic tape cassette, the trapezoidal portion 7 is not yet fixed, and the mechanical stability of the trapezoidal portion 7, that is, the entire cassette is reduced. At present, the strength has not been improved compared to the screw tightening type. That is, the present invention is intended to solve the above-mentioned inconvenience, and aims to improve the strength of the trapezoidal portion of the upper and lower cassette halves by ultrasonic welding, and to prevent deformation of the trapezoidal portion due to welding. It is an object of the present invention to provide a magnetic tape cassette composed of a cassette half which has improved mechanical stability of the trapezoidal portion, improved productivity and reliability of the product while preventing deterioration of running property.

[0008]

[Means for Solving the Problems]

 The above object of the present invention is to provide a magnetic tape cassette having a trapezoidal portion in the center of the front surface, in which a pair of tape winding bodies in which a magnetic tape is rotatably wound is housed in a case body composed of a pair of upper and lower cassette halves. A bottom plate that is flush with the surface of the top plate of the cassette half when viewed from the welding head side, and an end face that extends to the same level as the abutting portion of the side plates of the upper and lower cassette halves. This is achieved by a magnetic tape cassette in which individual tubular portions are formed in the trapezoidal portion, and the end portions of the tubular portions are fixed by welding together with the contact portions of the side plate portions of the upper and lower cassette halves. It

[0009]

Embodiment

 Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show one embodiment of the present invention, and FIG. 1 is an enlarged sectional view of the upper cassette half of the upper and lower cassette halves taken along line xx in FIG. 2 for convenience. FIG. 2 is a plan view of the upper cassette half. In the magnetic tape cassette 1 shown in FIG. 2, a pair of upper and lower cassette halves 2a (the lower cassette half 2b is not shown) has an end face of the side plate portion 6 (indicated by diagonal lines in FIG. 2) like the conventional welding type. It is also welded in the region B) and also in the tubular portion 8 (details will be described later) located inside the trapezoidal portion 7. Inside the magnetic tape cassette 1, a pair of hubs 4 around which the magnetic tape T is wound are rotatably supported by reel shaft insertion holes 4a and 4b as in the conventional case. . As a matter of course, the cassette half 2a has some protrusions, ribs, partition walls, side plate portions 6 and the like on the inner side of the flat plate-like top plate portion 5 as in the conventional case, and the entire shape thereof is substantially U-shaped in cross section. The trapezoidal portion 7 having a trapezoidal planar shape is formed in the front portion of the cassette.

To describe the structural features of this embodiment, the cylindrical tubular portion 8 is formed integrally with the trapezoidal portion 7 and extends inwardly of the cassette. As shown in the drawing, a bottom plate 9 is formed at the middle position of the inside of the cassette of the cylindrical portion 8 and is flush with the extension line of the surface of the top plate portion 5. Further, in the structure of the tubular portion 8, the position of the end face 8a is the same as the position of the end face 6a of the side plate portion 6 (the position indicated by the line C), and the end faces 8a, 6a and the ceiling face are the same. The distance h from the surface of the plate 5 is the same. The wall thickness of the bottom plate 9 is substantially the same as the wall thickness of the top plate portion 5. Further, the both end faces 8a, 6a are provided with appropriate projections 10 which are welding whites. The position of the tubular portion 8 is formed on the boss portion to which the screw 3 of the trapezoidal portion of the conventional cassette shown in FIG. 3 is attached.

On the other hand, the ultrasonic welding machine is inserted into the cylindrical portion 8 in addition to the outer peripheral portion 20 of the welding head which is in contact with the outer peripheral portion (the portion corresponding to the region B) of the cassette half as in the conventional case. Further, there is provided a cylindrical portion corresponding portion 21 having a circular cross section which abuts on the bottom plate 9. Then, in a state where the upper and lower cassette halves are overlapped with each other, the upper and lower cassette halves are intermittently continuously conveyed by a conveying means and conveyed to the ultrasonic welding machine, and as shown in FIG. 1, an outer peripheral portion of the welding head. 20 and the cylindrical portion corresponding portion 21 are in contact with each other at a predetermined position, and the upper and lower hasset halves are welded by ultrasonic energy of the welding head.

As described above, the upper and lower cassette halves can be continuously and quickly joined simply by abutting the ultrasonic vibrator (welding head) corresponding to the shape of the cassette half 2a in advance. Moreover, the bottom plate 9 of the cylindrical portion 8 integrally molded with the upper cassette half 2a is formed on the same plane as the extension line of the surface of the top plate portion 5, and the bottom plate 9 is formed on the surface of the top plate portion 5. On the other hand, since the distance between the end surface 6a of the side plate portion 6 and the end surface 8a of the tubular portion 8 is equal, the distance between each welding portion and the tip of each welding head can be equalized. Therefore, the supply of the welding energy by the ultrasonic welding machine to each welding portion becomes uniform, the welding can be performed in the same time, and stable and strong uniform welding can be performed. As a result, even if the product is inadvertently dropped, the impact resistance of the entire cassette is greater than that of the conventional welding type cassette, there is no risk of damage, and the trapezoidal portion 7 is strongly welded. Since it is fixed, the verticality of the guide pin 11 formed in the trapezoidal portion can be ideally secured, so that the magnetic tape T can be stably transferred. Moreover, the assembly is easy, the productivity is improved, the cost of the product is reduced, and the excellent effect that the intended purpose of the present invention can be sufficiently achieved is achieved.

In the embodiment, one tubular portion 8 is formed in, for example, a substantially central region of the trapezoidal portion 7 (a portion corresponding to a boss portion for conventional screw tightening). If necessary, a plurality of tapes may be provided as long as they are selected and determined so as not to interfere with the tape drive mechanism. Further, the shape of the cylindrical portion 8 does not have to be circular as in the above-described embodiment, and may be, for example, a rectangular shape or a partition shape elongated in the lateral direction of the cassette.

[0014]

[Effect of the device]

 As described above, the present invention is a magnetic tape cassette having a trapezoidal portion that forms the front opening of the cassette, and has a bottom plate in the middle that is flush with the surface of the top plate of the cassette half when viewed from the welding head side. At least one tubular portion is formed in the trapezoidal portion and has an end face extending to the same level as the contact portion of the side plate portion of the upper and lower cassette halves. The end face of the tubular portion is welded and fixed together with the contact portion. Therefore, according to the present invention, the trapezoidal portions of the upper and lower cassette halves can be ultrasonically welded, the cassette strength can be improved, and the degree of welding between the outer peripheral portion of the cassette and the welding portion in the trapezoidal portion can be made uniform. By preventing deformation of the trapezoidal part due to welding, the verticality of the guide pins can be kept good, and tape runnability can be prevented, productivity can be improved and product reliability can be improved.

[Submission date] November 8, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

[0013] In the embodiment, the tubular portion 8 is set to one formed with the structure substantially at the center of the realm example of the trapezoidal portion 7 (position corresponding to the boss portion of a conventional screw fastening) As long as it is determined by selecting a position that does not interfere with the tape drive mechanism, it does not matter if more than one tape is provided. Further, the shape of the cylindrical portion 8 does not have to be circular as in the above-described embodiment, and may be, for example, a rectangular shape or a partition shape elongated in the lateral direction of the cassette.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part of an upper cassette half taken along line xx of FIG. 2 in a magnetic tape cassette of the present invention.

FIG. 2 is a plan view showing a magnetic tape cassette of the present invention.

FIG. 3 is a perspective view of a conventional magnetic tape cassette.

[Explanation of symbols]

 1 magnetic tape cassette 2a, 2b cassette half 3 screw 4 hub 4a, 4b reel insertion hole 5 top plate part 6 side plate part 6a end face 7 trapezoidal part 8 tubular part 8a end face 9 bottom plate 10 protrusion 11 guide pin T magnetic tape

Claims (1)

[Scope of utility model registration request] 1. A magnetic tape cassette having a trapezoidal portion in the center of the front surface, which has a pair of tape winding bodies in which a magnetic tape is rotatably wound in a case body composed of a pair of upper and lower cassette halves. At least 1 has a bottom plate in the middle which is flush with the surface of the top plate of the cassette half when viewed from the head side, and has an end face extending to the same level as the abutting portion of the side plates of the upper and lower cassette halves.
A magnetic tape cassette, wherein individual tubular portions are formed in the trapezoidal portion, and the end portions of the tubular portions are fixed by welding together with the abutting portions of the side plate portions of the upper and lower cassette halves.