JPH0734507Y2 - Tape tension measuring cassette - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a tape cassette which is mounted on a deck of a tape recorder or a video tape recorder to measure the tension applied to the tape by a feeding mechanism of the tape deck.

[Conventional technology]

A tape tension measuring cassette (hereinafter referred to as a cassette) is a tape feeding mechanism incorporated in the deck of a tape recorder or a video tape recorder, specifically, a device for measuring the tape feeding force by a combination of a pinch roller and a capstan. , A cassette half is equipped with a rotation gauge on the supply reel. The rotation gauge is composed of a combination of an inner ring fixed to the cassette, an outer ring around which a tape is wound, and a spiral spring that connects the two, and the outer ring has a scale and the inner ring has a pointer. By loading this cassette on the tape deck and passing the tape pulled out from the peripheral surface of the rotating gauge between the pinch roller and the capstan of the deck and feeding the tape in the recording or playback state, the relative inside and outside rings of the rotating gauge The tape tension value is displayed on the scale due to the rotational displacement.

However, when the take-up reel is driven by the reel stand of the deck, the driving force is applied to the tape. Therefore, in order to measure a more accurate tape tension value, a mechanical friction is conventionally provided which is a reel for tape winding and which is rotatably combined with each other, and an inner ring, an outer ring, and a spring which gives a constant frictional force between the two rings.・ The clutch was used.

[Problems to be solved by the device]

When the friction clutch described above is used in a tape winding reel of a cassette, the frictional force between the two wheels is mechanically obtained by the pressure contact force of the spring interposed between the inner and outer rings. There is a problem in that the stability of the frictional force is lacking due to the above variations and due to wear of the spring due to friction, expansion and contraction of the spring due to temperature changes, or changes over time.

Further, it is difficult to secure a space between the small inner and outer rings, and to insert a spring in this space, as well as in manufacturing and assembling work.

An object of the present invention is to provide a cassette that solves the above problems.

[Differences from the Prior Art of Invention]

The tape winding reel of the cassette of the present invention is different from the conventional cassette in that the frictional force between the inner and outer rings is obtained by the magnetic attraction between the magnetic body and the magnet.

[Means for Solving the Problems]

To achieve the above object, in a tape tension measuring cassette according to the present invention, a supply reel, a winding reel, and a tape are built in a cassette body, and a supply side reel is added to the tape by using a rotation gauge. A tape tension measuring cassette for measuring tension, in which one end of a tape is fixed to a supply reel and is wound around the supply reel, and the other end of the tape pulled out from the supply reel is a deck of a tape recorder or a video tape recorder. It is mounted on the peripheral surface of the take-up reel via the corresponding tape feed line between the capstan and the pinch roller provided in the. The inner and outer rings, the spiral spring interposed between the two rings, and the relative rotational displacement generated between the two rings according to the tape tension are displayed. The inner ring is fixed to the cassette body, the outer ring is a tape wound around the outer ring, and the winding reel is an inner and outer concentric combination. ， Has an outer ring, and the inner ring is coupled to the reel stand of the deck and rotates integrally with the reel stand of the deck in the recording and playback states. It has a magnet, and the magnet exerts a magnetic attraction force on the outer ring. The outer ring is made of magnetic material, and the tape is attached to the outer surface.
After the tape is rotated integrally with the inner ring within the range of the frictional resistance due to the magnetic attraction force of the magnet of the inner ring and the tape tension exceeds the frictional resistance due to the magnetic attraction force, the rotation is stopped while slipping on the attraction surface of the magnet.

〔Example〕

Next, the cassette of the present invention will be described with reference to the drawings.

FIG. 1 (a) is a view showing an embodiment of the cassette of the present invention,
1 (b) is a longitudinal sectional view showing the rotation gauge of FIG. 1 (a), and FIGS. 2 (a) and 2 (b) are longitudinal and transverse sectional views showing the structure of the tape winding reel, respectively. .

In FIG. 1A, a tape winding reel 2 and a rotation gauge 3 as a tape supply reel are built in a cassette body 1, and a tape 12 drawn from the peripheral surface of the rotation gauge 3 is a cassette. It is tied to the peripheral surface of the tape winding reel 2 through the feed line of the front window hole. Rotation gauge 3
As shown in FIG. 1 (b), an inner ring 6 fixed to the cassette body 1 by a pin 11 and an outer ring 7 having one end of a tape 12 fixed and wound around its peripheral surface were interposed between the inner ring 6 and the outer ring 7. It has a combination with a spiral spring 8, the outer ring 7 is provided with a scale of tension value, and the inner ring 6 is provided with a pointer. A bearing 14 is interposed between the inner ring 6 and the outer ring 7 of the rotary gauge 3 to reduce the resistance between the inner and outer rings.

Further, the tape winding reel 2 is shown in FIG.
As shown in (b), the inner ring 4 having a projecting edge 16 for coupling the reel stand on the inner edge and the outer ring 5 made of a magnetic material, such as iron, are combined in a concentric manner so that they can rotate relative to each other. A ring-shaped magnet 15 (for example, a ferrite magnet) is housed in the space, the inner peripheral surface of the ring-shaped magnet 15 is fixed to the inner ring 4, and the magnetic poles are magnetized to the surface of the outer ring 5. Further, 17 is a lid for closing the ring-shaped magnet portion, and 18 is a stopper for fixing one end of the tape 12 to the outer ring 5.

Next, the operation will be described. As in the prior art, when the cassette of the present invention is loaded on a tape deck (not shown) to be in a recording or reproducing state, the tape 12 is fed by a pinch roller and a capstan (not shown), and the magnet 15 of the tape winding reel 2 is fed. The inner and outer rings 4, due to the magnetic attraction of
5 rotates integrally, and the tape 12 is wound around the peripheral surface of the rotating gauge 3 against the spring force of the spiral spring 8. When the feeding of the tape 12 is stopped, the outer ring 5 of the tape take-up reel 2 stops rotating due to the tension of the tape 12 and is separated from the rotational force of a reel stand (not shown), so that the magnetic attraction force between the inner and outer rings is increased. To give the tape 12 a tension. At this time, the tape 12 is mainly subjected to a feed force between a pinch roller and a capstan (not shown), so that the outer ring 7 of the rotary gauge 3 is rotationally displaced, and the tape tension value is indicated on the scale 9 by the pointer 10.

The frictional force can be adjusted by forming a film of Teflon or the like on the attraction surface between the ring-shaped magnet 15 and the outer ring 5. If a rare earth cobalt magnet or the like is used in place of the ferrite magnet, the frictional force can be adjusted to several tens. Can be doubled.

[Effect of device]

As described above, according to the cassette of the present invention, only the magnet is provided between the inner and outer rings of the tape take-up reel, which facilitates the manufacture and assembly, and also reduces the frictional force due to the magnetic attraction force. Since it is applied, it is not affected by changes in frictional force due to wear due to mechanical friction and changes in temperature, the magnitude of magnetic force can be freely set by selecting the type of magnet, stable frictional force can be obtained, and tape tension is accurate. There is an effect that can be measured.

[Brief description of drawings]

FIG. 1 (a) is a plan view showing the structure of the tape tension measuring cassette of the present invention, FIG. 1 (b) is a longitudinal sectional view showing the gauge of FIG. 1 (a), FIG. 2 (a), (B) is a longitudinal and transverse sectional view of the tape winding reel of FIG. 1 (a). 1 ... Cassette body, 2 ... Tape winding reel 3 ... Rotation gauge, 4,6 ... Inner ring 5,7 ... Outer ring, 8 ... Spiral spring 9 ... Scale, 10 ... Pointer 11 ... Pin, 12 ... Tape 13 ... Guide roller , 14… Bearing 15… Ring magnet, 16… Edge

Claims (1)

[Scope of utility model registration request] 1. A tape tension measuring cassette in which a supply reel, a winding reel, and a tape are built in a cassette main body, and the tension applied to the tape is measured by using a rotation gauge on the supply reel. , The tape is wound around its circumference with one end fixed to the supply reel, and the other end pulled out from the supply reel corresponds between the capstan and the pinch roller provided on the deck of the tape recorder or the video tape recorder. It was attached to the peripheral surface of the take-up reel via the tape feed line, and the rotation gauge used for the supply reel was interposed between the inner and outer rings that were concentrically combined with the inner and outer rings and between the two wheels. It has a spiral spring and a scale and pointer that indicate the amount of relative rotational displacement that has occurred between the two wheels according to the magnitude of tape tension.The inner ring is fixed to the cassette body. The outer ring has a tape wound around its outer surface, and the winding reel has inner and outer concentric inner and outer rings, and the inner ring is connected to the reel stand of the deck. It rotates integrally with the reel stand of the deck during recording and playback, and has a magnet. The magnet exerts a magnetic attraction force on the outer ring, and the outer ring is made of a magnetic material and has a tape on its peripheral surface. Installed,
The inner ring should rotate integrally with the inner ring within the range of frictional resistance due to the magnetic attraction force of the magnet, and after the tape tension exceeds the frictional resistance due to the magnetic attraction force, the rotation should stop while slipping on the attraction surface of the magnet. A tape tension measuring cassette characterized by