GB2210356A

GB2210356A - Video cassette: tape guide roll

Info

Publication number: GB2210356A
Application number: GB8822710A
Authority: GB
Inventors: Sun Kag Hong
Original assignee: SKC Co Ltd
Current assignee: SKC Co Ltd
Priority date: 1987-09-28
Filing date: 1988-09-28
Publication date: 1989-06-07
Anticipated expiration: 2008-09-28
Also published as: JPS6452181U; GB2210356B; GB8822710D0

Abstract

To rotatably support video tape guide rolls 21, base portions 23, poles 24 and the lower half body 22 of the cassette are integrally formed at the time of molding, whereby removing the use of the separate roll support pins. The heights of the base portions 23 are made equal to each other. <IMAGE>

Description

CASSETTE FOR VIDEO TAPE The present invention relates to a cassette for a video tape, particularly to a beta-type video tape cassette in which the tape line guide roll on the cassette is improved.

As shown in Figure 1 partly, the conventional cassette for a video tape contains a supply reel 2 and a take-up reel 3 within its case. The tape 4 is wound from the supply reel 2 to the take-up reel 3, guided by components such as a line guide roll 5, a supply roll 6, a take-up roll 7 and a line guide roll 8.

In the loading mode, the tape is pulled between the supply roll 6 and the take-up roll 7, is contacted on a rotary head in the deck mechanism, and is guided by the line guide rolls 5and 8, whereby preventing vibrations or damage to the tape.

Even if there are large variations in the diameter of the tape roll, the tape can be maintained in the correct position along the running path owing to the functions of said line guide rolls 5 and 8. The supply roll 6 and the take-up roll 7 guide the tape which runs from the reel 2 to a pinch roller in the deck mechanism, and receive the tape which returns to the head, while supporting the tape when the cassette is not being used. The line guide rolls 5 and 8 not only guide the tape, but also keep the dynamic eauilibrium of the tape which influe:ices the display quality.

In order to simplify the construction of the ahove-described conponents and to reduce the manufacturing cost of them, so,me modifications were made to the conventional device. Instead of the line guide rolls 5 and 8, metal poles were set up. Or as shown in figures 2 and 3, the lower nalf body 1 was provided with bosses 11,11', on which suspension pins 10 were put in, so that they could stand upright, and rolls 12', 12' were made to be supported on the suspensions pins 10. But the pins 10 and the rolls 12 were manufactured separately, and had to undergo an assembly process such as insertion of the pins and fitting of the rolls, ultimately resulting in an increase of the manufacturing cost for the cassette.

Further as shown in Figure 4, the boss 11' on the take-up side was made to be a little lower than the boss 11 on the supply side, and the roll 12' on the take-up side was made to be a little longer than the roll 12 on the supply side. Therefore the forming dies for them were separately prepared, leading ultimately to an increase in the manufacturing cost.

Furthermore, such an arrangement brouqht the result that the tape 4 ran in an inclined state, and so vibrations occurred in the displayed images.

Summary of the Invention The present invention is intended to provide solutions to the above described disadvantages.

Therefore it is the object of the present invention to provide a cassette for a video tape which allows the reduction of the manufacturing cost and can prevent the vibrations of the displayed images.

In order to realize the object, the present invention provides a structure in which the poles are integrally formed with the lower half body of the cassette, the heights of the base portions are made to be equal to each other, and uniform tape guide rolls are fitted onto the poles respectively.

An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings.

Brief description ! the Drawings Figure 1 is an exploded perspective view showing the lower cass and the reels of a cassette; Figure 2 is a sectional view of a conventional supply side line guide roll; Figure 3 is a sectional view of a conventional take-up side line guide roll; Figure 4 is a sectional view of a conventional structure in which the tape is installed between the supply roll and the guide roll; Figure 5 is a sectional view of the structure of the guide roll according to the present invention; and Figure 6 is a sectional view of the device of the present invention, in which the tape is installed on the guide roll according to the present invention.

Description of the preferred embodiment The above object and other advantaqes of the present invention will become more evident by describing the preferred embodiment of the present invention in more detail with reference to the attached drawings.

To form a line guide, a base portion 23 and a pole 24 are integrally formed on a lower half bodv 22, and, on such an integral pole 24, one of unifo!m- sized guide rolls 21 is rotatively coupled.

In the same way as in the conventional type, silicone oil is applied to the contact area between the pole 24 and the roll 21. The height oe the base portion 23 is made the same as that of the base on the upper side of the conventional device, while the uniform-sized poles 24 and rolls 21 can have a precise diameter and smooth surface. Therefore, their movements are smooth, and they do not generate any scratches on the tape surface when they contact it.

The device of the resent invention thus constituted has the advantages as described below. As the base portion 23 and the pole 24 are integrally formed with the lower half body 22, it is no longer necessary to separately nanufacture or procure an expensive and neatly round suspension pin and an expensive and neatly ground line guide pole. Also the assembling process for these parts can be skipped.

Other advantages coming from the removal of the separate suspension pin are that the tape does not have to have a sliding contact with the line guide, consequently contributing to the protection of the tape, and that, compared with the conventional separate suspension pin, the pole integrally formed on the lower half body 22 according to the present invention can maintain a precise and secure posture, ultimately leading to a reduction in defective products.

Further, as the two line guide rolls can maintain the same height both at the supply side and at the take-up side, the dynamic eauilibrium of the tape can be maintained more securely, whereby improving the displayed imaqe quality through the reduction of vibrations.

Thus the present invention provides a cassette for a video tape in which line guide rolls are formed even without using the suspensions pins, and in which the manufacturing cost is reduced but the qualitvw is improved.

Claims

1. A cassette for a video tape wherein the base portions and poles of the tape guide rolls are integrally formed with the lower half body of the cassette, the height of the base portions are made equal to each other, and uniform-sized guide rolls are rotatively coupled to each of said poles.

2. A cassette for a video tape, substantially as hereinbefore described with reference to Figs 1, 5 and 6 of the accompanying drawings.