Magnetic tape loading method and apparatus

A method and apparatus for loading a magnetic tape into a cassette in which the tape winding appearance is controlled and improved. Friction sheets are disposed around the hub onto which the tape is to be wound, preferably on both sides of the tape winding area. Compressed air is blown into the cassette to press the friction sheets against the edges of the tape as the tape is wound.

BACKGROUND OF THE INVENTION 
The present invention relates to a magnetic tape loading method and 
apparatus therefor. More particularly, the invention relates to a magnetic 
tape loading method and apparatus for initially loading a magnetic tape on 
a flangeless-type tape winding body in a cassette such as an audio tape 
cassette, a digital audio cassette or the like. 
The known processes for manufacturing magnetic tapes, such as audio 
cassette tapes, video cassette tapes and the like include a process for 
winding a magnetic tape of a predetermined width on a small-diameter 
flangeless type tape winding body such as a reel, a hub or the like, from 
a roll of "raw" magnetic tape, as an intermediate manufacturing process. 
In the case where a magnetic tape is wound on a tape winding body using 
such a process, various tape winding characteristics such as vibration in 
the direction of tape thickness, vibration in the direction of tape width, 
and the like change according to the physical properties of the raw 
magnetic tape, the physical properties of the tape winding body, and the 
physical properties of the magnetic tape itself. As a result, a problem 
arises in regard to the winding appearance (winding condition) of the 
magnetic tape wound on the tape winding body. In other words, winding 
difficulties arise so that the edges of the tape are uneven. Particularly, 
as the tape running speed during winding is increased, the tape edges 
become more uneven. 
Of course, a magnetic tape in which the tape edges are uneven has a poor 
external appearance when the tape is placed in a magnetic tape cassette. 
Further, there arises a problem in that the tape edges are easily damaged, 
thereby inducing various types of problems and causing a deterioration of 
the electromagnetic conversion characteristics of the tape. 
Therefore, in the prior art magnetic tape manufacturing process, all tapes 
must be visually checked with respect to the winding appearance after the 
aforementioned loading process. This adds significantly to the total cost 
and time required in the manufacturing process. 
In order to reduce this checking burden, and for the purpose of improving 
the winding appearance, a method called "cap decorative winding", which is 
an open-type winding method and which is illustrated in FIG. 7, has been 
employed for loading a magnetic tape. 
FIG. 7 is a schematic perspective view showing a take-up site tape winding 
body 2. 
FIG. 7 shows the winding of a magnetic tape on a flangeless-type tape 
winding body while the magnetic tape T is pushed on one side by the weight 
of a cap 15 placed on the tape winding body mounted on a turntable 14 
provided with a take-up shaft 4. According to this method, opposite edges 
of the tape T can be adjusted so that the tape T will have a good winding 
appearance after being wound on the tape winding body. 
However, such an open winding type take-up method involves some risk of 
tape damage because it requires a process of placing the magnetic tape 
winding body in the cassette case. Further, the method results in certain 
assembling difficulties. 
Another tape winding method, called "in-cassette winding", "C-0 winding" or 
"V-0 winding", has been proposed in which the magnetic tape is loaded only 
in the last step of the cassette assembly process. This method includes 
steps of assembling all parts in advance, except for the magnetic tape, 
into a cassette 8 as shown in FIG. 8 to form a unit into which a feed site 
tape winding body and a take-up site tape winding body connected by a 
leader tape 10 are inserted in the cassette. The leader tape is cut by use 
of a take-up apparatus called an "in-cassette winder". One end of a first 
leader tape is connected to one tape winding body of the cassette, while 
the other end of the leader tape is temporarily held by a holding member 
16. The tape winding body 2, connected to the raw magnetic tape T through 
another leader tape, is rotated to take up the magnetic tape T. The 
magnetic tape T is cut off at a predetermined length. Lastly, a terminal 
end of the wound magnetic tape T is bonded to the other end of the first 
leader tape 10 to produce the finished article. 
The above-described in-cassette winding type take-up method has an 
excellent manufacturing efficiency, but has disadvantages as follows. 
First, it is impossible to adjust the edges of the magnetic tape by 
contact as described above for cap decorative winding. Accordingly, the 
winding appearance will vary with the physical properties of the tape and 
the quality of various cassette parts, and hence the winding appearance 
cannot be controlled and sometimes is poor. Particularly, in the case 
where the tape winding body is of the flangeless type, it is very 
difficult to control the winding appearance. 
SUMMARY OF THE INVENTION 
In view of such circumstances, an object of the present invention is to 
provide a magnetic tape loading method and apparatus for loading a 
magnetic tape in which the winding appearance of the magnetic tape is 
greatly improved, even for so-called in-cassette type winding in which 
there has heretofore been no effective means for improving the winding 
appearance. 
The foregoing and other objects of the invention have been attained by a 
magnetic tape loading method for loading a magnetic tape into a cassette 
case containing a pair of flangeless-type tape winding bodies connected by 
a leader tape with at least one friction sheet being in contact with an 
edge of the magnetic tape, characterized in that the magnetic tape is 
taken up while the tape winding bodies are rotated and while compressed 
air is fed into the cassette case to thereby press the friction sheet 
against the edge of the magnetic tape. 
The invention further encompasses an apparatus which enables this method to 
be carried out, that is, a magnetic tape loading apparatus for loading a 
magnetic tape into a cassette case containing a pair of flange-less type 
tape winding bodies connected to each other through a leader tape and at 
least one friction sheet in contact with an edge of the magnetic tape, 
characterized in that the apparatus is provided with compressed-air 
feeding means for feeding compressed air into the cassette case from at 
least one reel shaft insertion hole formed in the cassette case.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A preferred embodiment of the apparatus according to the invention will be 
described in detail hereunder. 
FIG. 1 is a schematic front view of a preferred embodiment of an 
in-cassette winding type magnetic tape loading apparatus, and FIG. 2 is a 
side view taken from the direction of an arrow A in FIG. 1. The apparatus 
1 is used for winding a magnetic tape T on a pair of tape winding bodies 2 
and 3 (hereinafter referred to as "hubs") incorporated in advance in, for 
example, a digital audio tape cassette. 
The operation of the tape loading apparatus 1 will now be described. 
A cassette case 8, containing the hubs 2 and 3 connected to each other 
through a leader tape 10 having a predetermined length, is mounted in a 
cassette holder 20 of the loading apparatus 1. The structure of the 
cassette holder 20 is similar to that used in a general 
recording/reproducing apparatus. For example, as shown in FIG. 3, when the 
cassette case 8 is inserted downward into the box-like cassette holder 20, 
the cassette case 8 is held within the holder by a fitting member 21 
provided at a suitable position on a lower end of the holder. In this 
condition, a guard panel 8a closing a front opening portion of the 
cassette case 8 is made movable. That is, in this condition, a slidable 
guard 8b provided at the bottom surface of the cassette case 8 and serving 
as a guard panel stopper is slid backward corresponding to the insertion 
of the cassette case 8. 
Then, the cassette holder 20 supported, for example, by four slide shafts 
23, is moved toward a front panel 1a (in a direction of an arrow B) by the 
action of two air cylinders 24 so that a driving shaft 4 and a shaft 5 are 
inserted into the hubs 2 and 3 from reel shaft insertion holes 8c. In this 
condition, the guard panel 8a is pushed up by a guard panel lever 22 
mounted on the front panel 1a so as to be moved corresponding to the 
motion of the guard panel 8a so that the guard panel 8a is opened to 
expose the leader tape 10 connecting the hubs 2 and 3. 
Then, the leader tape 10 is cut off about at its midpoint. The cut end of 
the leader tape 10 connected to the hub 2 is bonded through a bonding tape 
or the like to a forward end of a supply of raw magnetic tape 6. The 
magnetic tape T is taken up through a predetermined length on the hub 2 
and then is cut off, whereafter the cut end of the magnetic tape T is 
bonded to the cut end of the part of the leader tape 10 connected to the 
hub 3. 
The cutting of the leader tape 10 and the magnetic tape T and the bonding 
between the leader tape 10 and the magnetic tape T are carried out by a 
cutting and bonding unit 9 having tape end holding members 10a and 10b, a 
cutter, a bonding tape supply, etc. The magnetic tape T fed from the 
supply of raw tape 6 is wound on the hub 2 through a path defined by 
various guide pins and guide rollers. 
After the magnetic tape T bonded to the leader tape 10 of the hub 3 has 
been taken up on the hub 2, the cassette holder 20 is moved in the 
direction of an arrow C in FIG. 7 (in the opposite direction to the arrow 
B) through the action of the air cylinders 24. The connection between the 
driving shaft 4 and the hub 2 and the connection between the shaft 5 and 
the hub 3 are released so that the guard panel 8a is allowed to close the 
front opening portion of the cassette case again. Then, the fitting 
members 21 by which the cassette case 8 is held move backward to the rear 
of the cassette holder so that the cassette case 8 can be removed from the 
lower part of the holder. 
The cutting and bonding unit 9 is omitted for clarity of illustration in 
FIGS. 2 and 3. The invention will be described more in detail with 
reference to FIGS. 4 and 5. The aforementioned cassette holder 20 and the 
like are not shown in FIGS. 4 and 5 for convenience of description. 
FIG. 4 is a schematic sectional view showing the driving shaft 4, which is 
rotated by a driving device (not shown) such as a motor or the like, under 
the condition where the driving shaft 4 and the shaft 5 are inserted into 
the cassette case 8. The shaft 5 is hollow. One end of the shaft 5 is 
connected to a pipe 30 connected to a pressure pump (not shown) to thereby 
form a compressed air feeding arrangement for feeding compressed air into 
the cassette case 8. 
When compressed air is fed into the cassette case 8 in this manner, the air 
from the forward end of the shaft 5 strikes the upper surface of the 
inside case wall opposite the forward end of the shaft 5, and then spreads 
in all directions against the side opposite that contacting the type of an 
upper friction sheet 11 (in the space between the wall surface and the 
friction sheet 11) along the upper wall surface. In this condition, the 
upper friction sheet 11, which is flexible, is pressed by the compressed 
air so as to be suitably curved toward the inside of the case. After the 
air flows along the upper wall surface of the air flows along the side 
wall surface of the cassette case 8 and then flows along the bottom wall 
surface thereof to press a lower friction sheet 12 towards the inside of 
the case in the same manner as the upper friction sheet. Thereafter, the 
air flows out of the case from the front opening portion of the cassette 
case. 
When the magnetic tape T is wound on the hub 2 through the rotation of the 
driving shaft 4 under the condition that the upper and lower friction 
sheets are pressed by compressed air toward the inside of the case as 
described above, the winding position of the magnetic tape T with respect 
to the hub 2 and the winding appearance thereof are very good because the 
positions of the upper and lower edges of the magnetic tape T are 
controlled by the respective friction sheets. 
The air pressure, the air flow rate and the like of the compressed air are 
not specifically limited. For example, they can be established 
corresponding to the tape winding speed, the characteristics of the 
friction sheets 11 and 12, such as thickness, hardness, smoothness and the 
like, and other factors, such as the internal structure of the cassette 
case. Further, the shaft 5 need not always be completely fixed and may be 
movable if necessary. For example, the shaft 5 may be connected to the 
pipe through a rotary joint. 
Although the above embodiment has been described with reference to the case 
where compressed air is fed through the shaft 5, it is to be understood 
that the invention is not limited thereto and that, for example, a 
funnel-shaped pipe covering the reel shaft insertion hole 8c as shown in 
FIG. 5, that is, a funnel-like member 17 having suitable flexibility, may 
be placed in contact with the outside surface of the case. 
Further, as shown in FIG. 9, the cassette case 8 may be substantially 
entirely covered by a cassette holder 40. The cassette holder 40 is 
provided with a flat nozzle 41 so that the flat nozzle 41 is positioned 
substantially directly under one of the reel shaft insertion holes 8c when 
the holder 40 covers the cassette case 8. One end of the flat nozzle 41 is 
coupled to the pipe 30 to thereby flow the compressed air into the 
cassette case 8 through the flat nozzle 41 and the hole 8c. 
By providing such a rotary joint with a hollow driving shaft 4, the 
compressed air can be fed from the driving shaft 4. For example, by 
feeding the air from two places into the cassette case 8, the effect 
provided by the compressed air can be enhanced. 
Further, although the above embodiment has been discussed with reference to 
the case where two friction sheets (upper and lower) are provided, the 
invention is applicable to the case where only one friction sheet is 
provided. Furthermore, the friction sheet need not be flexible as 
described above, and may be formed of a plate-like member having a 
suitable stiffness. 
Still further, although in the above-described preferred embodiment the 
invention is applied to a digital audio tape cassette, it is a matter of 
course, as previously described, that the invention can be applied to a 
Philips-type audio tape cassette. In the case where the invention is 
applied to such a magnetic tape cassette, the funnel-like members 17 can 
be fitted to the reel shaft insertion holes 8c from the reverse side to 
the shafts 4 and 5 as shown in FIG. 6 because the reel shaft insertion 
holes 8c open both to the front and the rear sides of the cassette case. 
Accordingly, it is easy to feed compressed air from both reel shaft 
insertion holes 8c. 
As described above, according to the invention, when in-cassette winding of 
the magnetic tape cassette containing a pair of flangeless type hubs and 
at least one friction sheet is to be carried out, the edges of the 
magnetic tape are pressed by the friction sheets through the action of 
compressed air fed into the cassette case to thereby control the winding 
behavior of the tape and to obtain therefore a remarkably improved winding 
appearance. 
The following example serves to illustrate more clearly the preferred 
embodiment of the present invention. 
EXAMPLE 
A digital audio tape cassette was used as the magnetic tape cassette. 
In-cassette winding was carried out upon the cassette by use of an air 
feeding structure as shown in FIG. 6. 
The upper friction sheet was formed of 50 .mu.m thick polyethylene, and the 
lower friction sheet was formed of 80 .mu.m thick hypermolecular 
polyethylene. 
The pressure of the compressed air was 1.5 kg/cm.sup.2. An estimation of 
the winding appearance was made under the conditions that the winding 
speed of the tape and the number of friction sheets were as shown in the 
Table below. 
In the Table, A indicates "very good", B "good", C "slightly poor", and D 
"very poor". 
It is apparent from the Table that Samples 1 to 4 according to the 
invention were superior in winding appearance to comparative Samples 5 and 
6.