JPS5834616Y2 - Torque meter for tape cassettes - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a torque meter for a tape cassette equipped with a reel hub wrapped with magnetic tape, and in particular, the reel hub drive shaft is engaged with the reel hub of the tape cassette and rotated by hand. The present invention relates to a device configured to easily indicate whether or not the rotational friction torque at that time is at least in an appropriate range for stable running of the magnetic tape.

When using a cassette-type tape recorder, the running of the magnetic tape becomes unstable and the playback output fluctuates periodically, often resulting in failure to obtain a normal output.

When we investigate the causes of such fluctuations, we find that they can be roughly divided into two types: those due to instability of the drive system in the tape recorder, and those due to defects such as deterioration of the cassette tape itself. .

In general, even if a tape recorder has normal operating performance, if the rotational friction force of the magnetic tape in the tape cassette exceeds a certain limit, the running of the magnetic tape will become unstable, and the worsening of wow and flutter will become noticeable. However, it is no longer suitable for audio appreciation.

In such a case, the user of the tape recorder tends to mistakenly believe that there is a failure in one of the drive systems of the tape recorder due to the occurrence of such wow and flutter.

However, the occurrence rate of wow and flutter deterioration phenomena in tape recorders is extremely low, and is often caused by fluctuations in the rotational friction torque of the magnetic tape itself.

The cause of such rotational friction torque fluctuations is considered to be the effect of repeatedly running the cassette tape.

Therefore, if there is something that can quickly determine the cause and easily and accurately determine whether the problem is caused by the tape recorder itself or the cassette tape itself, general users would With this, appropriate recording and reproduction can be performed, which is extremely convenient.

However, conventionally, the reel drive shaft insertion hole of the tape cassette was
The rotational friction torque of a cassette tape was experimentally measured by inserting a pencil or the like and rotating it with one's fingers, but such a method relies on human intuition, resulting in significant measurement errors. It required a fair amount of judgment and was not something that anyone could easily do.

The present invention was devised in view of such conventional problems, and therefore, the object of the present invention is to provide a drive member at the tip for rotating the reel of a tape cassette by hand. , a system for cassette tapes with a simple configuration and high measurement accuracy, which indicates whether or not the rotational friction torque is at least within the appropriate range for stable running of the magnetic tape, depending on the rotation of the drive member. There is a torque meter to provide.

An embodiment of the present invention will be specifically described below with reference to the drawings.

Figures 1A and 2 are front cross-sectional and front views of the torque meter according to the present invention, and numeral 1 denotes a cylindrical body constituting the main body of the torque meter. An annular recess 2 is provided.

A central shaft is rotatably supported within the recording cylinder 1 on three bars, and a supporting shaft 4 having a somewhat larger diameter is connected to the lower part of the central shaft.

An arcuate surface 5°6 is formed in the stepped portion between the support shaft 4 and the central shaft 3.

Further, a drive shaft 7 is formed at the lower end of the central shaft 3 to be engaged with an engagement protrusion of a reel shaft insertion hole of the reel.

This drive shaft 7 has a claw piece or a polygonal portion on its circumferential surface.

Furthermore, a bearing 8 is interposed within the annular recess 2 so as to cover the periphery of the support shaft 4.

This bearing 8 has a cylindrical body as shown in FIGS. 3 and 4, and has three dove-shaped notches 9 at equally spaced positions on the inner side of the end surface of the cylindrical body to support ball bearings to be described later.
, 10 are provided, and furthermore, between each of the above-mentioned bowl-shaped notches 9, 10, there are small holes 11, 1 into which a pin as described below is inserted.
2 is provided.

However, the number of the above-mentioned bowl-shaped notches 9 and 10 buttons and the number of pores 1L12 are arbitrarily selected.

Ball bearings 13 and 14 are housed in the button notches 9 and 10 and the arcuate surfaces 5 and 6. Bearing covers 15°16 are provided.

As shown in FIGS. 5 and 6, this bearing cover 15.16 has three bowl-shaped notches 17, each of which accommodates the ball bearings 13.14, at three equally spaced positions on one end face. The pin 18 is provided with substantially the same dimensions as the shaped notches 9 and 10, and furthermore, a pin 18, which is inserted into the small hole LL12, is provided protruding from the end surface between these.

A bracket 19 is attached to the lower end of the cylindrical body 1 with a screw 20.

On the other hand, a stepped portion 21 is formed at the upper open end of the section body 1, and a scale disc 22 is installed on this stepped portion 21.

1, the upper end of the center @3 passes through the center hole of the graduated disc 22 and faces above, and its tip is a conical part 23 formed with a sharp edge.

The lower part of the conical portion 23 is provided with the graduated disc 22.
A pointer 24 is attached so as to face upward.

Here, torque values are calibrated on the scale disc 22, and as shown in FIG. 7, the disc 25 is divided into three sections according to color (or on the ground, if necessary) to ensure that the rotational friction torque of the cassette tape is appropriate. It is designed to indicate whether or not it is within the area.

Reference numeral 26 denotes a cover formed of a transparent member that closes the opening in the -L direction of the cylindrical body 1. For example, as shown in FIG. By being fitted into the annular notch 28 provided on the outer peripheral surface of the body 1, the opening of the cylindrical body 1 is closed.

A bracket 30 housing bearings 29 is attached to the lower side of the top plate of the cover 26, and the conical portion 23 of the central shaft 3 is brought into smooth contact with these ball bearings 31. Therefore, the position of the upper end of the central shaft 3 in the radial direction and the thrust direction is regulated.

That is, only by attaching the cover 26 to the cylinder 1, the position of the central shaft 3 in the radial direction and the thrust direction can be easily regulated.

In this way, the central axis 3 coincides with the axis of the cylindrical body 1, ensuring smooth rotation.1. No matter how large the load is on the drive shaft 7, the center @3 can be rotated correctly and smoothly.

Attachments of various shapes for measuring light torque can be attached to the sprout 1 and the drive shaft I as needed.

Reference numeral 32 denotes a coil spring fitted to the central shaft 3, one end of which is fixed to the circumferential surface of the central shaft 3, and the other end fixed to the inner circumferential direction of the cylindrical body 1 with a screw or other fixing means. Retained.

Next, to use a torque meter with such a configuration,
The drive shaft 7 of the torque meter is fitted into the hub pawl 34 of the tape cassette 33 as shown in FIG. 2, and the knurled portion 35 formed around the lower part of the cylindrical body 1 is rotated by pinching it with a hand or fingers.

This rotation biases the coil spring 32 in the direction of contraction, but if the rotational friction torque of the tape cassette is small or while the reel is spinning, the above-mentioned The central shaft 3 rotates simultaneously with the coil spring 32.

When the rotational friction torque of the cassette tape increases, the spring 32 is greatly compressed and contracted as the cylindrical body 1 rotates, and it is only when the spring 32 has advanced to a certain point that the center shaft 3 is moved upward. It follows the rotation of the cylinder 1.

Therefore, by observing the scale on the scale disc 22 indicated by the pointer 24 or the indicator area as shown in FIG. It is determined whether it is a thing or not.

In this way, according to the present invention, the radial direction button and thrust direction support of the center shaft can be reliably carried out at both ends.
This prevents the upper end of the center shaft from independently vibrating or bending in the radial direction, ensuring a smooth rotating button and accurate indexing at the upper part of the cylindrical body of the pointer.

That is, in the present invention, by supporting the central shaft on both sides, there is an advantage that smooth rotation of the central shaft and accurate indexing as described above can be performed.

As described above, the present invention includes a central shaft rotatably supported by a cylinder via a bearing, a drive shaft for a reel hub connected to the lower end of the central shaft, and the central shaft and the cylinder. a coil spring fixed at both ends to the cylindrical body; a dial plate disposed at the top of the cylinder body; a pointer attached to the end of the central shaft facing the top of the dial plate; and a pointer that covers the pointer. a transparent cover attached to the upper part of the cylindrical body, and a shaft end attached to the inside of the transparent cover so as to support the central shaft end, and the central shaft is supported substantially at both ends thereof. By supporting the tape recorder, general users can easily determine whether or not the wow and flutter of the cassette tape is caused by the cassette tape itself when using a tape recorder. By supporting the part where the pointer is attached with a bearing, the rotation of the upper part of the central axis is restricted in the radial direction and thrust direction, which has the advantage that measurement can be performed accurately. , rich in practicality.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a front sectional view of the torque meter according to the invention, FIG. 2 is a front view, FIG. 3 is a front view of the bearing, and FIG. 4 is a front view of the same. Cross section, 5th
The figure is a flat view of the bearing cover, and Figure 6 is a front sectional view.
FIG. 7 is a plan view of the scale disc, and FIG. 8 is a sectional view of the main parts showing the structure for attaching the cover to the cylinder. 1... Cylindrical body, 3... Center shaft, 7... 1 Drive shaft, 8
... Bearing, 13.14 ... Ball bearing, 22
... Graduation disk, 23 ... Central shaft end (conical part),
24...Pointer, 26...Cover 29...Bearing,
30...Bracket.

Claims (1)

[Scope of utility model registration request] A central shaft rotatably supported by a cylindrical body via a bearing, a drive shaft for a reel hub connected to the lower end of this central shaft, and a coil whose both ends are fixed to the central shaft and the cylindrical body. a spring, a scale plate disposed at the top of the cylindrical body, a pointer attached to the end of the central shaft facing the top of the scale plate, and a pointer attached to the top of the cylindrical body so as to cover the pointer. comprising an attached transparent cover and a bearing attached to the inside of the transparent cover so as to support the central shaft end;
A torque meter for a tape cassette, characterized in that the central shaft is supported substantially at both ends thereof.