JPH0287035A - Torque measuring apparatus of cassette tape driving system - Google Patents

Abstract

PURPOSE:To easily perform the precise calculation of torque and to correspond to the measurement of torque of every kind by one means by arranging a strain gauge for detecting the tension applied to a tape at the time of the taking-up of the tape as strain stress to a tape running system. CONSTITUTION:A pair of reels 26, 28 are provided in a cassette half 24 in a freely rotatable manner and a magnetic tape 30 having a required length is fixed at the respective end parts thereof through clamps 26a, 28a. This tape 30 is guided by the guide rollers 32, 34 of standard positions on a side partially exposed from a cassette main body at the corner parts of the half and separate guide rollers 36, 38 close to said rollers. Further, one ends of a pair of metal elastic pieces 40, 42 are fixed to the almost center of the half 24. Guide rollers 44, 46 having a small diameter are pivotally supported by the other free ends of said elastic pieces in a freely rotatable manner and the tape 30 passed around rollers 32, 34, 36, 38 runs so as to go around the rollers 44, 46. The strain gauges 48 respectively arranged to said elastic pieces 40, 42 convert fine deformation generated by mechanical stress to an electric signal.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a torque measuring device for a cassette tape drive system. The present invention relates to a device capable of measuring the torque of a cassette drive system with simple operation, with high precision and at low cost, in a recorder in which a cassette wound with ribbon tape for printing, etc., is removably mounted in a recorder.

BACKGROUND OF THE INVENTION Tape recorders and other video recorders that magnetically record audio and video and reproduce audio and video are now widely used. These recorders use magnetic tape as a recording medium, but in recent years most magnetic tapes have shifted from open-reel type magnetic tapes that are simply wound on reels to standardized cassette types that are easy to handle. For example, cassettes used in audio recording tape recorders include the Philips standard, the Olympus standard microcassette, and the DAT standard. Furthermore, there are various types of video cassettes for magnetically recording video and audio, such as the VIS standard, the Beta standard, and the Hemiri standard.

In each of the various cassettes described above, two reels are rotatably provided at a required interval in a standardized cassette half, and a magnetic tape is wound on both reels so as to be able to run. In this sense, the cassette is a closed type in which the magnetic tape is not exposed to the outside, and has the advantage of effectively preventing dust from adhering to the cassette. A cassette of this standard is easily installed by fitting each corresponding reel (also called a hub) to the two drive shafts of the tape drive system installed in the recorder body, and is activated by operating a lever or push button on the recorder. The tape drive system can be selectively operated to perform recording, playback, rewinding, and fast forwarding on the tape.

Furthermore, in character recording devices such as English typewriters and word processors, ribbon tapes for printing have been made into cassettes to facilitate handling when replacing them.

Depending on the model, these cassetted ribbon tapes are not only simply wound up, but also wound and rewound by a tape drive system built into the character recording device.

Problems to be Solved by the Invention When assembling the above-mentioned tape recorders, video recorders, etc. on a production line, the cassette tape drive system of the recorder is inspected in the final process. For example, for audio tape recorders that record and playback audio, this inspection examines: ■ the tape winding torque during recording and playback; ■ the rotational torque of each drive shaft during tape rewinding and ■ tape fast forwarding. Therefore, the measured values are required to fall within a predetermined range at each testing stage. That is, if the torque measured at each measurement step deviates from the predetermined range in the positive or negative direction, the test is rejected.

Currently, when measuring the torque of this type of cassette tape drive system, the entrance point is inspected using the original type of measuring instrument. That is,
When recording on a cassette tape, it is necessary to feed the tape while pressing it with a pinch roller, and since braking is applied by a felt pad while the tape is being fed, the torque to be measured constantly changes depending on various conditions. Therefore, conventionally, one of the pair of reels 12 and 14 provided inside the cassette 10, as shown in FIG.
2, one end of the spiral spring 16 is attached to the other end of the spring 16, and a magnetic tape 18 is fixed to the other end of the spring 16.
The other end is wound around the other glue 14. A pointer 20 provided at a suitable position on the tape 18 is used to determine whether or not the measured torque is within a predetermined value range, depending on the position where the pointer 20 points to the tension scale 22 marked on the cassette body.

However, in the torque measuring device of this configuration, good accuracy cannot be obtained because the elasticity of the spiral spring itself varies, and it easily deteriorates with frequent use, etc. Moreover, it is expensive as a whole because it is disposable. There are drawbacks such as. Furthermore, it is troublesome to replace the cassette each time depending on the tension of the spiral spring to suit the purpose of torque measurement, and it is also pointed out that this method is difficult to apply to automatic machines.

Furthermore, in character recording devices such as word processors that wind and unwind cassetted ribbon tapes, as far as the inventors know, no measurements are performed using torque detection.

Purpose of the Invention The present invention has been proposed in order to suitably solve the above-mentioned disadvantages inherent in the torque measurement of the cassette tape drive system in a cassette recorder, and to facilitate accurate torque measurement. It is an object of the present invention to provide a torque measuring device which can handle all kinds of torque measurements with a single device.

Means for Solving the Problems In order to overcome the above-mentioned problems and achieve the intended purpose, the present invention provides a torque reduction system for a cassette tape drive system that winds and rewinds a tape stored in a short-circuited cassette. The measuring device is a measuring device in which each end of a tape of a required length is attached to a pair of reels provided in the cassette, forming a tape running system that can be freely wound up and rewound by the reels, and when the tape is wound up, the tape is The present invention is characterized in that a strain gauge for detecting tension applied to the tape as strain stress is disposed in the tape running system.

Another object of the present application is to provide a torque measuring device for a cassette tape drive system in a recorder that uses a cassette tape as a magnetic recording medium and performs magnetic recording and/or playback of audio, video, etc. using this tape. Each end of a tape of the required length is attached to a pair of reels, forming a tape running system that can be freely wound and rewound using the reels. This can also be achieved by disposing a gauge in the tape running system.

Embodiment Next, a preferred embodiment of the cassette tape drive system torque measuring device according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic plan view showing a preferred embodiment of a torque measuring device according to the present invention, in which a Phillips standard cassette exterior is used as is for the main body of the device. In the illustrated cassette half 24, a pair of reels 26 and 28 are rotatably provided according to the standard, and both reels 26 and 28 are rotatably provided.
, 28, a magnetic tape 30 of a required length is fixed at each end of the magnetic tape 30 via clamps 26a'+28a. This magnetic tape 30 is a cassette half 24
A guide roller 32 provided at a standard position on the corner of the cassette body and on the side where the tape 30 is partially exposed from the cassette body.
．． 34 and another guide roller 36.38 provided in close proximity to this guide roller 32.34.

Furthermore, a pair of metal elastic pieces 40, 42 are fixed to substantially the center of the cassette half 24 at one end thereof. Small-diameter guide rollers 44.46 are rotatably supported at the other free ends of the metal elastic pieces 40.42, and as described above, the guide rollers 32 (34) and 3
The magnetic tape 30 stretched past the small diameter guide roller 44 (46) runs around the small diameter guide roller 44 (46).

Each elastic metal piece 40, 42 is provided with a strain gauge 48 as a transducer that converts minute deformation caused by mechanical stress into an electrical signal. An output lead wire 50 is connected to the strain gauge 48, and the lead wire 50 is drawn out of the cassette body 24 and connected to a measuring device (not shown).

When using the torque measuring device constructed in this manner, the device is loaded into the cassette tape drive system of a recorder arriving at the inspection line.

This torque measuring device includes the output lead wire 50 described above.
The measuring instrument is connected via. In this state, the cassette tape drive system of the recorder is operated. That is, when the cassette tape drive system operates and a driving force is applied to one reel 26, the reel 26 winds up the tape 30, and the tape 30 is fed out from the other reel 28.

This tape running applies tensile stress to the elastic piece 40.42, and an electrical signal is output from the strain gauge 48 provided on the elastic piece 40.42 to an external measuring device, where the signal is processed. Ru. This measuring device displays the obtained torque on a screen such as a CRT, records it with a printer, and also uses means such as sound and light to check whether the torque is within a predetermined value range. It is possible to make the person aware of the

FIG. 2 shows another embodiment of the torque measuring device according to the invention, in which also a strain gauge 48 is provided in relation to the tape running system within the cassette. That is, a detection plate 52 on which a strain gauge 48 is disposed is pivotally supported at a suitable position approximately in the center of the cassette half 24 via a pin 54, and a small-diameter guide roller 56 provided at the free end of the detection plate 52, The magnetic tape 30 is guided through in a detour. As a result, when the cassette main body 24 is attached to the cassette tape drive system of a recorder and inspected under various running conditions, the reel drive shaft in each mode of fast forwarding, rewinding, recording (recording), and playback of the tape will be affected. The applied torque is accurately measured.

Effects of the Invention As described above, according to the cassette tape drive system torque measuring device according to the present invention, since the strain gauge is provided in the standardized cassette in relation to the internal tape running system, this cassette can be measured. By simply attaching the device to the cassette tape drive system of the target recorder, torque can be measured under the actual cassette drive conditions. Moreover, unlike the conventional one, 1
Torque measurement in all modes can be carried out continuously with one device, it can be adapted to mechanization, and since it is durable, it can be used for a long time and is economical.

In the embodiments of this application, the torque measuring device for the tape drive system of an audio tape recorder has been mainly explained, but the present invention is not limited to this, and the torque measuring device can also be used for a video recorder for video or the torque of the aforementioned printing cassette ribbon. Of course, it can also be suitably used as a measuring device.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a schematic configuration of an embodiment of a torque measuring device for a cassette tape drive system according to the present invention, FIG. 2 is a schematic plan view showing another embodiment of the device of the present invention, and FIG. FIG. 1 is a plan view showing a schematic configuration of a torque measuring device used in the prior art. 24...Cassette half 26.28...Reel 30...Magnetic tape 32.
34, 36.38...Guide roller 40.42...
Metal elastic piece 44.46...Guide roller

Claims (1)

[Scope of Claims] [1] A torque measuring device for a cassette tape drive system that performs winding and rewinding of a tape stored in a standardized cassette, comprising: Each end of a long tape is attached to form a tape running system that can be freely wound up and rewound by the reel, and a strain gauge that detects the tension applied to the tape during tape winding as strain stress is attached to the tape running system. A torque measuring device for a cassette tape drive system, characterized in that the device is installed in a cassette tape drive system. [2] A torque measuring device for a cassette tape drive system in a recorder that uses a cassette tape as a magnetic recording medium and performs magnetic recording and/or reproduction of audio, video, etc. using this tape, which measures the torque of a pair of cassette tapes installed on the cassette. Each end of a tape of the required length is attached to a reel to form a tape running system that can be freely wound and unwound by the reel, and a strain gauge is installed to detect the tension applied to the tape as strain stress when the tape is wound. A torque measuring device for a cassette tape drive system, characterized in that it is disposed in the tape running system.