JPH0244362Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cassette tape type torque gauge for measuring the winding or unwinding torque of a tape such as a video tape recorder.

For video tape recorders, it is necessary to test the rotational torque of the drive unit as a test of the finished product.
For this inspection, a torque gauge with a torque meter built into the cassette case has traditionally been used.
This is installed in a tape recorder and the torque is measured while the tape is running or stationary. This cassette tape type torque gauge is
A reel with an arrow on the inner ring and a rotating torque indication scale on the outer ring, with the inner and outer rings connected by a spiral spring, is assembled into a cassette case as a torque meter.
The inner ring was connected to the rotating shaft of the tape recorder, a tape was wound between the outer ring and the outer ring of the other reel, and the tape was fed while measuring the torque while the tape was running or at rest. However, since the torque is read by visually observing the indicator scale on the outer ring indicated by the arrow on the inner ring, it is extremely difficult to read the indicator value when the tape is running at high speed.

The object of the present invention is to provide a cassette tape type torque gauge that eliminates the above-mentioned problems.

In order to achieve the above object, the cassette-type torque gauge of the present invention has a pair of tape reels for winding tape built into the cassette case, and at least one of the tape reels has a double inner and outer ring structure to connect the two wheels. Connected by a spiral spring, between the inner and outer rings,
On one ring, a plurality of stripes that are optically or magnetically detected without contact over a certain area range are attached radially at regular intervals as counting markers, and on the other ring, the spiral spring is unloaded. Covering all the stripes of the marking in the state, a number of stripes proportional to the rotational torque due to the relative rotational displacement between the two wheels are optically or magnetically applied from a fixed position externally through the window of the cassette case for each revolution of the tape reel. A shield is provided with a cutout that allows the sensor to be exposed in a state where it can be detected visually.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figures 2 and 3 show the proposed torque gauge.
That is, the tape reel loaded in the cassette case 1 has a double ring structure with an inner ring 2 and an outer ring 3,
An inner ring 2 is rotatably mounted on an outer ring 3 via a ball bearing 4, and a spiral spring 5 wound around the inner ring 2 provides a predetermined rotational resistance to the rotation of both the inner and outer wheels. Further, the inner ring 2 has an insertion hole 6 into which a rotating shaft of a video tape recorder or tape recorder is fitted.

Furthermore, as shown in FIGS. 1 to 3, a non-reflective plate 8 is laid on the upper surface of the outer ring 3 within the opening range of the internal see-through window 7 provided in the cassette case 1, and a non-reflective plate 8 is placed on the non-reflective plate 8. Linear stripes 9, 9, . . . made of highly reflective aluminum foil or the like are radially attached as counting markers over a certain area. On the other hand, in the inner ring 2, when the spiral spring 5 is not loaded, all the stripes 9, 9... of the outer ring 3 are covered, and the number of stripes 9, 9... is exposed in proportion to the rotational torque caused by the relative rotational displacement of both wheels. A fan-shaped shield 10 having a notch on the side edge is installed. Further, a tape is stretched between the outer rings 3, 3 of the two gauges assembled in the cassette case 1. The torque gauge of the present invention is installed in a video tape recorder (or tape recorder) and is installed above the cassette case 1. An optical sensor 11 is installed to count the number of reflective stripes partially exposed from the shield 10 through the window 7 or the change in area. It is used in combination with

In this embodiment, when the cassette case 1 is loaded into a video tape recorder, the rotating shaft of the video tape recorder fits into the insertion hole 6 of the inner ring 2.
When the rotating shaft of the video tape recorder is rotated in this state, the inner ring 2 receives the rotational force and rotates against the spring pressure of the spiral spring 5, and as shown in FIG. 10 rotates in the direction of the arrow, a portion of the reflective stripes 9, 9, . . . that have been covered by the shield 10 appear outside. The number of reflective stripes 9 exposed to the outside is detected by an optical sensor 11 until the number is balanced with the winding or rewinding torque of the video tape recorder, and the sensor 11
Calculate the rotational torque based on the output. In addition, instead of reflective stripes as signs, magnets may be used and installed with alternating poles, and the number of them may be detected by a magnetic sensor. The configuration of the sensor that detects the number of exposed labels is not limited to that of the embodiment. Further, in the embodiment, a shield was installed on the inner ring and a marker was installed on the outer ring, but it is also possible to install a marker on the inner ring and a shield on the outer ring.
Furthermore, as is clear from Fig. 3, the reflective stripes were exposed to the outside from the shield 10 as the inner ring 2 rotated, but conversely, all of the reflective stripes were exposed to the outside at the start of the measurement. Then, as the inner ring rotates, it may be covered with a shield 10 to detect the decrease in the number and display the torque value.

Further, in the above description, the present invention has been described as a torque gauge used in a video tape recorder, but it goes without saying that the present invention can also be applied to a torque gauge used in an audio tape recorder.

As described above, the present invention installs a mark on one of the inner and outer rings and a shield that covers the mark on the other, and uses a sensor to detect changes in the number or area of the marks exposed to the outside from the shield when measuring torque. Since the torque value is displayed, the torque value can be easily read and the efficiency of torque measurement work can be improved. Furthermore, since the number of marks is detected based on changes in area, even if the inner and outer rings vibrate relative to the cassette case, accurate torque values can be measured by taking the average value over several revolutions. Another advantage is that there is no need to change the structure of the cassette case.

[Brief explanation of the drawing]

Figure 1 is a front view showing one embodiment of the present invention;
The figure is a cross-sectional side view of the torque meter unit, and FIG. 3 is a front view of the torque meter unit. DESCRIPTION OF SYMBOLS 1... Cassette case, 2... Inner ring, 3... Outer ring, 5... Spiral spring, 9... Reflective stripe (sign), 10... Shielding body, 11... Optical sensor.

Claims (1)

[Scope of utility model registration request] A pair of tape reels for winding the tape are built into the cassette case, and at least one of the tape reels has a double inner and outer ring structure, and the two rings are connected by a spiral spring. A plurality of stripes that can be optically or magnetically detected without contact are attached radially at regular intervals over a certain area range as counting markers, and the stripes are attached to the other ring in the unloaded state of the spiral spring. Cover all the stripes and apply a number of stripes proportional to the rotational torque due to the relative rotational displacement between the two wheels to one of the tape reels from a fixed position outside through the window of the cassette case.
A cassette-type torque gauge characterized in that a shield is provided with a notch that is exposed to an optically or magnetically detectable state every rotation.