JPH0612581B2 - Braking device and reel rotation control device - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to a novel braking device. More specifically, the present invention relates to a braking device that controls the rotating operation of a rotating body that supplies and winds a tape, so that the braking force applied to the rotating body and the braking timing can be freely controlled to achieve a braking state according to various braking purposes. The present invention is intended to provide a new braking device capable of obtaining the above.

BACKGROUND ART AND ITS PROBLEMS Rotating bodies such as video tape recorders (hereinafter "VTR")
It is necessary to perform braking according to each operation mode for the magnetic tape wound around the tape reel which is engaged with and rotates the reel base. That is, the running speed of the magnetic tape is set in each operation mode, that is, reproduction (FW
D) mode, fast forward (FF) mode, rewind (REW)
Mode, high-speed playback (CUE) mode, reverse playback (RV)
S) mode, high speed reverse reproduction (REV) mode, etc. are different from each other such as high speed, medium speed and low speed. Therefore, it is necessary to give an optimum tension to the magnetic tape according to the speed of each mode. To this end, it is necessary to brake the reel base with a braking force according to each mode. Moreover, such brake braking for the reel base, that is, braking for stopping the rotation of the reel base, is performed on the reel base on the supply side (hereinafter referred to as “S side”) and the reel base on the winding side (hereinafter referred to as “T side”). It is necessary to carry out at different timings suitable for the platform. For example, when switching from the FF mode state to the stop (STOP) mode, the magnetic tape is running at a high speed from the S-side tape reel toward the T-side tape reel. There is no problem if the brakes are applied to both the S-side reel base and the T-side reel base at the same time, but if the T-side reel base is braked earlier than the S-side reel base, the S-side reel base Since the magnetic tape comes to be sent out without being wound by the T-side reel, slack occurs in the tape,
This is because it causes so-called backlash.

However, since braking of the reel base in the conventional VTR is performed only by the friction braking type brake mechanism in which the braking operation is mechanically performed, when braking or braking according to each mode as described above. Couldn't get the right timing.

FIG. 1 shows an example of a conventional reel stand braking device in a VTR. In the figure, a indicates an S-side reel stand, and b indicates a T-side reel stand, which are rotatably supported by reel shafts d and d'standingly provided on a chassis c, respectively. Gear teeth (not shown) are formed on the outer peripheral surfaces of the disk portions e, e ', and gear teeth of a drive gear rotated by a reel motor (not shown) are meshed with the gear teeth. Reference numerals f and f'represent drum parts projecting upward from the upper surfaces of the disk parts e and e'of the reel stands a and b.
Reference numeral g denotes a first rotating plate which is arranged behind the drum portion f ′ of the T-side reel stand b and near the S-side reel stand a, and h
Is on the rear side of the drum part f of the S-side reel stand a and on the T-side reel stand b
Is a second rotary plate arranged at a position close to the center of the rotary plate g and h.
It is rotatably supported on the upper ends of the pins i and i'standing on the ground. A protrusion j is provided on the upper surface of the end of the first rotating plate g on the side of the T-reel base b facing the drum portion f ', and the drum shoe k is wound around the protrusion j. This drum shoe k is brought into contact with the outer peripheral surface of the drum portion f'by rotating the first rotating plate g in the clockwise direction (the state shown by the solid line in the figure). Further, by rotating the rotating plate g in the counterclockwise direction, the drum portion f '
The contact with the outer peripheral surface of the is separated (state shown by a chain double-dashed line in the figure). Similarly to this, a protrusion 1 is provided on the upper surface of the end of the second rotating plate h on the side of the S reel stand a facing the drum part f, and the brake shoe m is attached to the protrusion l. Is attached in a wound shape, and the brake shoe m is brought into contact with the outer peripheral surface of the drum part f by rotating the rotating plate h in the counterclockwise direction (state shown by the solid line in the figure). Further, when the rotating plate h is rotated in the clockwise direction, the contact with the outer peripheral surface of the drum portion f is released (a state indicated by a two-dot chain line in the figure). n is an interlocking arm protruding from the center of the first rotating plate g toward the second rotating plate h side, o is a lever protruding rearward,
p is a protrusion protruding forward. q is an interlocking arm that protrudes from the center of the second pivot plate h toward the first pivot plate g, and the tip of this interlocking arm q is the first
The rotary plate g is located on the front side of the front end of the interlocking arm n with a slight distance. Reference numeral r denotes a tension coil spring that is bridged between the protrusion p of the first rotating plate g and the front portion of the second rotating plate h. The first and second rotating plates g and h are The pulling force of the spring r urges the turning force in the direction in which the brake shoes k, m are pressed against the outer peripheral surfaces of the drum parts f, f'of the reel stands a, b.

s is an electromagnetic plunger, which is supported by the chassis c by a support frame t, and the tip of the operating rod u is the first rotating plate g.
Is rotatably connected to the tip of the lever o. v is a mounting leg of the support frame t, and a long hole w extending along the axial direction of the plunger s is formed in the mounting leg v. The support frame t passes through the long hole w and the chassis It is attached to the chassis c in a position adjustable state by screws x screwed to c.

Then, when the electromagnetic plunger s is not excited, the first and second rotating plates g and h are in the state indicated by the solid line in the figure by the pulling force of the spring r. Brake shoes k and m of moving plates g and h
Are pressed against the outer peripheral surfaces of the drum parts f and f'of the reel stands a and b. Therefore, in this state, each reel stand a, b
Both are restrained from rotating and are braked. Then, when the electromagnetic plunger s is excited, the operating rod u is attracted toward the inside of the case, so that the first rotating plate g is rotated counterclockwise, and the brake shoe k thereof becomes T. The brake on the T reel base b is released by releasing the contact with the drum part f'of the reel base b.
Along with this, the tip of the interlocking arm n collides with the tip of the interlocking arm q of the second rotating plate h and presses it forward, so that the second rotating plate h moves in the clockwise direction. The brake shoe m is rotated to the drum part f of the S reel stand a.
The brake on the S-reel base a is released by releasing the contact with the outer peripheral surface of the. In this state, both reel stands a and b
Can be rotated by the reel motor (not shown). When the excitation of the plunger s is released again, the rotating plates g and h are rotated in a predetermined direction by the tensile force of the spring r, and the reel bases a and b are braked.

The braking device shown in FIG. 1 has the reel stands a and b as described above.
However, since the braking means is only a frictional contact type braking mechanism, it is not possible to selectively perform the optimum control according to the mode. That is, the reel stands a, b of the brake shoes k, m
Since the braking force acting on the reel base is always constant, the reel base a or b is braked with the same braking force whether it is rotating at high speed or at low speed. Therefore, in some cases, the braking force becomes too strong, which may give an abnormal tension to the magnetic tape, and in some cases, the braking force becomes too weak, making it ideal for a short time. Braking was difficult.

The braking device of the present invention has been made in view of the above-mentioned problems, and is a novel braking device capable of freely controlling the braking force applied to the rotating body for supplying and winding the tape and the braking timing. The purpose is to provide a device.

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the first braking device according to the present invention includes a first suction plate made of a magnetic material provided in each of two rotating bodies and the two rotating bodies. An electromagnetic braking mechanism comprising an electromagnet for electromagnetically attracting the first attraction plate, the terminal pins of which are connected to a printed wiring board arranged on a supported chassis, and a part of the two rotating bodies can be separated and contacted. A second friction member provided on the same and a height with respect to the printed wiring board that rotates integrally with the arm to which the friction member is fixed is substantially equal to the heights of the printed wiring board and the first suction plate. And a friction braking mechanism including an electromagnet that electromagnetically attracts the second suction plate, and the electromagnetic braking mechanism is used in the tape running mode when the tape is supplied and wound by the two rotating bodies. Using tape stop mode The second one is characterized in that the electromagnetic braking mechanism and the friction braking mechanism are used together, and the second one is a reel stand which is rotatably driven by mounting a reel for supplying and winding a tape. An electromagnetic braking mechanism including a plate-shaped first suction plate integrally formed of a magnetic material and a plurality of electromagnets arranged to face the first suction plate, and tape supply / winding A friction member, which is provided so as to be separable from and into a part of a reel base on which a reel to be taken is placed and is driven to rotate, and a pair of electromagnets that move the friction member in a direction of separating from the part of the reel base. And a friction braking mechanism provided with, and controls the rotation torque of the reel depending on whether the running speed of the tape is normal or high by controlling the current flowing through the coil wound around the electromagnet of the electromagnetic braking mechanism. And the winding reel from the supply reel. Characterized by being configured to switching control a pair of electromagnets to move the supply and take-up side of the friction member when a transition to a mode for forward running of the tape in series connection towards.

By doing so, it is possible to provide a novel braking device that is small in size and is capable of obtaining a braking state according to various braking purposes.

Embodiment Hereinafter, details of the braking device of the present invention will be described according to an embodiment shown in the accompanying drawings. The drawings show a VTR of the present invention.
2 shows an example of an embodiment applied to the reel stand braking device in FIG.

In the figure, 1 is a reel base chassis, and 2 is a drum side chassis which is arranged above the reel base chassis 1 so as to face it. The reel stand and the braking device in this embodiment are attached to the reel stand chassis 1 and arranged so as to be accommodated in the space between the reel stand chassis 1 and the drum side chassis 2. On the upper surface of the drum side chassis 2, a head drum having a video head (not shown), other various magnetic heads, a tape feeding mechanism, and the like are installed.

A printed wiring board 3 is arranged so as to overlap with the upper surface of the chassis 1, and is fixed to the chassis 1 by an appropriate fixing means such as screwing. Left and right of the central portion of the printed wiring board 3 (for convenience of explanation, in the description of this embodiment, the left-right direction in FIG. 2 is the left-right direction, the downward direction in the drawing is the front, and the upward direction in the drawing is the rear). ) On both sides, notches 6 are arranged at angular intervals of approximately 120 degrees in the circumferential direction around the positions of the shaft centers of the reel shafts 4 and 5 erected on the chassis 1, and extend radially from the center. , 6, 6 and 7, 7, 7 are formed, and
Between each of the notches 6, 6, 6 and 7, 7, 7, a hole 8,
8, 8 and 9, 9, 9 are respectively formed. A substantially U-shaped notch 10 is formed in the center of the rear side of the printed wiring board 3, and strip-shaped protrusions 11 and 12 project rearward from the left and right sides of the notch 10. ,
Further, notches 13 and 14 are formed on the left side of the protrusion 11 and the right side of the protrusion 12. Although illustration is omitted, a predetermined printed wiring is printed on the printed wiring board 3.

The reel shafts 4 and 5 are supported with their lower ends press-fitted into bosses 15 and 16 fixed to the chassis 1, respectively, and the upper parts thereof pass through holes 17 and 18 formed in the drum-side chassis to allow the chassis to pass through the chassis. 2 is projected above.

Reference numerals 19 and 20 denote reel stands, which are rotatably supported by reel shafts 4 and 5, respectively. Since the reel stands 19 and 20 have exactly the same configuration, one reel stand 19 will be described in detail, and the other reel stand will be denoted by the symbol "'" in addition to the one attached to the reel stand 19. The description is omitted by adding.

That is, reference numeral 21 denotes a shaft portion formed in a substantially cylindrical shape, the upper end of which is located slightly downward from the upper end of the reel shaft 4, the lower end of which is formed in a conical shape, and the lower end of which is friction. It is mounted on the upper surface of the boss 15 via a washer 22 made of a material having a low coefficient. Reference numeral 23 denotes an annular spring receiving portion that is provided so as to project outward from the substantially central portion of the shaft portion 21,
An annular groove 24 that opens upward is formed in the spring receiving portion 23. A disk portion 25 is integrally formed from the lower end of the spring receiving portion 23 toward the outside,
The disk part 25 has an outer diameter slightly smaller than the diameter of the hole 17 formed in the drum-side chassis 2 at a substantially central part in the radial direction, and the upper end surface of the disk-side chassis 2 has the outer diameter.
An annular wall portion 26 that protrudes upward from the upper surface of is integrally erected. An annular ridge 27 is formed at a position outside the annular wall 26 of the disk 25. Further, gear teeth 28, 28, ... Are formed on the outer peripheral surface of the disk portion 25. A circular shallow recess 29 having a shape seen from below is formed on the lower surface of the disk portion 25, and a plate-shaped suction plate 30 made of a magnetic material is fixedly mounted in the recess 29. .

Reference numeral 31 is a reel base cap, which is a flange 32 and annular projections 33 and 3 formed on the upper surface of the flange 32 doubly.
4 and the fitting tubular portion 35 projecting downward from the central portion of the lower surface of the flange 32 are integrally formed.

36 is a reel engagement shaft, which is formed in a substantially tubular shape,
Engaging projections 37, 37, which are arranged at equal intervals on the outer peripheral surface,
.. are integrally formed to project.

38 is a coil spring and 39 is a retaining washer.

Then, from the state in which the shaft portion 21 of the reel stand 19 is externally fitted to the reel shaft 4, the coil spring 38 is externally fitted to the shaft portion 21 so that the lower end portion thereof fits into the spring receiving groove portion 24, and then the shaft portion 21. 21, the reel engagement shaft 36 is externally fitted, and the reel tube cap fitting tubular portion 35 is externally fitted to the reel shaft 4. Finally, a retaining washer 39 is fitted in a groove 40 formed in the upper end portion of the reel shaft 4. Engage. As a result, the reel stand 1
9 and the reel base cap 31 are rotatably supported in a state in which they are prevented from coming off from the reel shaft 4, and the reel engagement shaft 36 has a flange 32 of the reel base cap 31.
Is supported between the lower surface of the coil spring 38 and the coil spring 38 so as to be vertically movable to some extent. Although not shown, the reel engagement shaft 36 is coupled to the shaft portion 21 of the reel base 19 by a slide key structure so as to be movable in the axial direction and integrally rotatable.

Then, the respective disk parts 25, 2 of the reel stands 19 and 20
The gear teeth of a drive gear rotated by a reel motor (not shown) are selectively meshed with gear teeth 28, 28, ... And 28 ', 28' ,. The reel bases 19 and 20 are rotated by the reel motor.

One reel stand 19 is a supply side (“S side”) reel stand, and the other reel stand 20 is a winding side (“T side”) reel stand, and a tape cassette (not shown) is attached to the VTR. Then, the S reel and the T reel of the tape cassette are respectively attached to the annular wall portions 26, 2 of the reel stands 19 and 20, respectively.
The reel engaging shafts 36, 36 'of the reel stands 19 and 20 are engaged with the reels of the tape cassette. Then, the tape is pulled out from the tape cassette by a tape pull-out mechanism (not shown),
It is set so that it passes a predetermined tape path. And
In the FWD mode, the recording (REC) mode and the RVS mode, the vehicle runs at a low speed, and in the CUE mode and the REV.
Runs at medium speed in mode, and in FF mode and R
It is sent at high speed in the EW mode. The tape is F
In the WD, REC, CUE and FF modes, T on the T reel stand 20 is pulled out from the S reel on the S reel stand 19
It is wound on a reel and wound from the T reel to the S reel in the REW, RVS, and REV modes.

41A and 41B are electromagnetic braking mechanisms, 42A and 42B are friction braking mechanisms, and the braking device of the present invention comprises both of these braking mechanisms.

First, the electromagnetic braking mechanisms 41A and 41B will be described. 41A is an electromagnetic braking mechanism related to the S reel stand 19, 41B is an electromagnetic braking mechanism related to the T reel stand 20, and these mechanisms 41A and 41B are the disk parts 25 and 25 of the reel stands 19 and 20, respectively. It is located below the ‘ And each of these electromagnetic braking mechanisms 41A and 4A
Each 1B is composed of a plurality of planar electromagnets (hereinafter, simply referred to as “electromagnets”) and a plurality of iron cores.

That is, 43a, 43b, and 43c are electromagnets of the electromagnetic braking mechanism 41A of the S reel stand 19, and are arranged at equal intervals on a concentric circle centered on the position where the reel shaft 4 is erected. The electromagnet 43 includes a bobbin 47 including a cylindrical shaft portion 44 and disc-shaped flange portions 45 and 46 formed at the upper end and the lower end of the shaft portion 44, and a coil wound around the shaft portion of the bobbin 47. 48 and an iron core 49 inserted into the hole of the shaft portion 44 of the bobbin 47. The upper flange portion 45 of the bobbin 47 is integrally formed with a protrusion 50 protruding outward from a part of the outer peripheral edge of the flange portion 45, and the tip end portion of the protrusion 50 is formed. The terminal mounting portion 51 is formed in a rising shape. 52, 52 are terminal pins whose upper ends are fixed to the terminal mounting portion 51 in an implanting manner, and both ends of the winding of the coil 48 are connected to the terminal pins 52, 52. A plurality of leg portions 53, 53, 53 are formed on the lower surface of the lower flange portion 46 of the bobbin 47 so as to project.

Reference numerals 54, 54, 54 denote mounting holes formed in portions corresponding to substantially the centers of the cutouts 6, 6, 6 formed on the printed wiring board of the chassis 1. The mounting holes 54, 54, 54 are surrounded by the mounting holes 54, 54, 54. Have small engagement holes 55, 55, ... Further, insertion holes 56, 56, ... Are formed adjacent to the outer ends of the cutouts 6, 6, 6 of the printed wiring board 3.

Therefore, the respective electromagnets 43a, 43b, 43c have their respective bobbins 47, 47, 47 fitted in the portions of the chassis 1 corresponding to the cutouts 6, 6, 6 of the printed wiring board 3 described above, and the respective protrusions. 50, 50, 50 are arranged at equal intervals on a circle centered on the reel shaft 4 so as to extend radially around the position of the reel shaft 4, and
The leg portions 53, 53, ... Are engaged with the engagement holes 55, 55, 55 ,.
The lower ends of 49, 49 are fixed to the mounting holes 54, 54, 54 by crimping, and the terminal pins 52, 52, ...
The lower end portion of the insertion hole 5 formed in the printed wiring board 3
6, 56, ... The leg portions 53, 5 inserted through the insertion holes 55, 55, ...
The parts protruding downward from the lower surface of the chassis 1 are crimped to form the retaining heads 3, which prevent the bobbins 47, 47, ... , The insertion hole 56 of the printed wiring board 3,
Terminal pins 52, 52, ...
Is soldered to a predetermined printed wiring formed on the printed wiring board 3. The lower ends of the iron cores 49, 49, 49 are fixed to the mounting holes 54, 54, 54 of the chassis 1 by caulking.

Reference numerals 57, 57 and 57 denote iron core bodies arranged between the bobbins 47, 47 and 47 of the electromagnets 43a, 43b and 43c, respectively. The iron cores 49 and 4 of the electromagnets 43a, 43b and 43c are provided.
9, 49 and the iron cores 57, 57, 57 are arranged at equal intervals on the same circumference. And the iron cores 57, 5
The lower ends of 7, 57 are fixed to the engaging holes 58, 58, 58 formed in the printed wiring board 3 of the chassis 1 at the portions corresponding to the holes 8, 8, 8 by caulking.

The iron cores 49, 49 of the electromagnets 43a, 43b, 43c,
The upper end surface of 49 is located at a position projecting upward from the upper end surfaces of the bobbins 47, 47, 47, and the upper end surfaces of the iron cores 57, 57, 57 are at the same level as the upper end surfaces of the iron cores 49, 49, 49. It is located. And these iron cores 49, 49, 4
9 and the upper end surfaces of the iron cores 57, 57, 57 and the suction plate 30 attached to the lower surface of the disk portion of the reel stand 19 are opposed to each other with a slight gap.

The electromagnetic braking mechanism 41B related to the T reel base 20 is constructed in exactly the same manner as the electromagnetic braking mechanism 41A on the S reel base 19 side. That is, 43d, 43e and 43
Reference numeral f denotes an electromagnet of the electromagnetic braking mechanism 41B of the T reel stand 20, which is arranged at equal intervals on the same circumference centered on the position where the reel shaft 5 is erected. These electromagnets 43d, 4
3e and 43f are the electromagnets 4 on the side of the S reel base 19 described above.
It has the same structure as 3a, 43b and 43c. Then, the electromagnet 4 is provided in a portion of the chassis 1 corresponding to the cutouts 7, 7, 7 formed on the printed wiring board 3.
Mounting holes 59, 59, 59 for fixing the lower ends of the iron cores 49, 49, 49 of 3d, 43e, 43f, and legs of the bobbins 47, 47, 47 around the mounting holes 59, 59, 59. The engaging holes 60, 6 through which the parts 53, 53, ... Are inserted.
0 are formed, and the terminal pins 5 are formed near the outer ends of the cutouts 7, 7, 7 of the printed wiring board 3.
Insertion holes 61, 61, ... through which 2, 52, ... Are inserted.
・ Is formed. Then, each electromagnet 43d, 43
e and 43f are the bobbins 47, 47, 47 or the cutouts 7, 7, 7 of the printed wiring board 3 of the chassis 1 described above.
Fits in the portion corresponding to and each of the protrusions 50, 50, 5
0s are arranged at equal intervals on the same circle centered on the reel shaft 5 so as to extend radially around the position on the same circle centered on the reel shaft 5, and each leg portion 53 , 53, ... Are inserted into the engagement holes 60, 60, ... Formed in the chassis 1, and the iron cores 49, 49, 49 are inserted.
The lower end of each of the terminal pins 52, 52, ... Is inserted into the holes 61, 61 ,. To be done. The holes 60, 60, ... Of the chassis 1
The parts of the leg portions 53, 53, ... Passed down that protrude downward from the lower surface of the chassis 1 are crimped to form a retaining head portion, whereby the bobbins 47, 47, 47 from the chassis 1 are removed. The terminal pins 52, through which the holes 61, 61, ...
The lower ends of 52, ... Are soldered to predetermined printed wiring formed on the printed circuit board 3.

Reference numerals 62, 62, and 62 are iron core bodies arranged between the bobbins 47, 47, 47 of the electromagnets 43d, 43e, 43f. The lower ends of the iron cores 62, 62, 62 are chassis 1
The printed wiring board 3 is fixed by caulking to the mounting holes 63, 63, 63 formed in the portions corresponding to the holes 9, 9, 9. Then, the electromagnets 43d, 4
The upper end surfaces of the iron cores 49, 49, 49 of 3e and 43f and the upper end surfaces of the iron core bodies 62, 62, 62 are slightly different from the suction plate 30 'mounted on the lower surface of the disk portion 25' of the T reel stand 20. They are facing each other with a wide gap.

Thus, the electromagnetic braking mechanism 41 configured as described above
In A and 41B, each electromagnet 43a, 43b, 43
c or coils 43d, 43e, 43f 48, 48, ...
.. When each of the electromagnets 43, 43, .. and the iron cores 49, 49, ... And the iron cores 57, 57, 57 or 62, 62, 62 are energized. A mold magnetic field is formed, and the magnetic force of this magnetic field acts as a suction force for the suction plate 30 or 30 'of the reel stand 19 or 20. Therefore, the suction plate 30 of the S reel stand 19 and the electromagnetic braking mechanism 41
Iron cores 49, 49, 49 of A and iron core bodies 57, 57, 57
Between them or between the suction plate 30 'of the T reel stand 20 and the iron core of the electromagnetic braking mechanism 41B, a viscosity is generated by magnetic attraction, and this viscosity becomes the braking force for the S reel stand 19 or the T reel stand 20. Become. The braking force applied to the reel bases 19 and 20 varies depending on the strength of this viscosity, that is, the strength of the magnetic attraction force. Incidentally, this electromagnetic braking mechanism 41A, 41
The control of braking on the S reel table 19 and the T reel table 20 by B will be described in detail later.

Next, the friction braking mechanisms 42A and 42B will be described. 42A is a friction braking mechanism related to the S reel stand 19, 42B is a friction braking mechanism related to the T reel stand 20, and these mechanisms 42A and 42B are the reel stand 1
It is arranged symmetrically in the rear part of 9, 20. Each of the friction braking mechanisms 42A and 42B is composed of a set of a flat electromagnet and a magnetic path body, a brake arm and a brake body including a suction plate, and the cutouts of the printed circuit board 3 of the chassis 1 respectively. It is provided in a portion corresponding to the portions 13 and 14.

That is, reference numeral 64 denotes a magnetic path body of the friction braking mechanism 41A on the S reel base 19 side, which is made of a magnetic material. Then, the base end portion of the base portion 65 formed in a substantially square shape in a plane shape,
That is, mounting holes 66, 66 are formed on both sides of the end portion of the printed circuit board 3 which is closer to the protruding portion 11, and the wall portions 67, 67, 67 are raised from the leading edge and the front and rear end edges. Is formed integrally with. A mounting hole 68 is formed in the center of the base portion 65. 43g is a plane type electromagnet having exactly the same structure as the electromagnets 43, 43, ... In the electromagnetic braking mechanism 41, and includes a bobbin 47, a coil 48 wound around the bobbin 47, and an iron inserted in the bobbin. It is composed of a core 49 and terminal pins 52, 52.

69 is a brake body. 70 is a plate-shaped support,
Legs 7 bent downward from both sides of the base end of the support 70
1, 71 are integrally formed, and an opening 72 having a substantially rectangular shape when viewed from above is formed in a substantially central portion of the support body 70. Pins 73, 73 protruding outward are formed at the lower ends of the legs 71, 71.

A suction plate 74 is formed of a magnetic material in a substantially square shape, and has a mounting hole 75 formed at a position close to the base end.
By being fitted with a protrusion 76 protruding downward from a position near the tip of the support body 70, the support body 70 is integrally attached to the support body 70.

Reference numeral 77 denotes a brake arm, which is integrally formed to project from the left side surface of the middle portion of the leg portion 71 of the support body 70 that is closer to the side on which the S reel stand 19 is located.
The disk portion 25 extends to a position facing the lower surface of the portion near the outer peripheral edge. A recess 78 is formed on the upper surface of the tip of the brake arm 77, and a protrusion 79 is formed on the lower surface of the brake arm 77. A brake shoe 80 is press-fitted into the recess 78.

The friction braking mechanism 42A on the S reel base 19 side is configured as described above, and the friction braking mechanism 42 on the T reel base 20 side.
B also has the completely same structure as this. Therefore, the description of the friction braking mechanism 42B on the T reel base 20 side will be omitted by attaching the reference numeral with "'" to the reference numeral attached to the friction braking mechanism 42A on the S reel base 19 side of the drawing. Incidentally, 43h indicates an electromagnet of the friction braking mechanism 42B on the T reel stand 20 side.

Reference numeral 81 denotes a rotation support portion of each brake body 69, 69 'in each of the friction braking mechanisms 42A, 42B. This rotation support portion 81 is provided at a portion corresponding to the cutout portion 10 of the printed wiring board 3 of the chassis 1. The pins 73, 73 and 73 ', 73', which are arranged and project on the leg portions 71, 71 and 71 ', 71' of the brake bodies 69, 69 ', are rotatably held. That is, reference numeral 82 denotes a pedestal, which is formed in a substantially rectangular shape in a plan view, and a notch portion which is cut out in a substantially U shape when viewed from above is formed at a portion of both left and right side ends close to both front and rear ends. And the receiving piece 83,
83 and 83 ', 83' are formed. Grooves 84, 84 and 84 ', 84' having a substantially U-shaped cross section are formed on the upper surfaces of the receiving pieces 83, 83 and 83 ', 83'. Further, reference numeral 85 is a holding plate, which is formed in a substantially rectangular shape in a plan view, and which vertically corresponds to the notches formed in the pedestal 82 in the portions close to the front and rear side ends of the left and right side ends. A similar notch is formed at the position, thereby forming the pressing pieces 86, 86 and 86 ', 86'. 87, 87, 87 are a holding plate 85 and a pedestal 82.
Is a mounting hole formed so as to vertically penetrate through the holding plate 85 and the pedestal 82 at a substantially central portion of the above.

Reference numerals 88 and 88 'denote openings formed in portions of the printed wiring board 3 of the chassis 1 corresponding to the cutouts 13 and 14, and 89, 89 and 89', 89 'denote the openings 8 described above.
8, 88 'and the protrusion 11 on the rear side of the printed wiring board 3,
Screw holes, 90, 90 and 9 formed in a portion between 12 and
Reference numerals 0 ', 90' denote insertion holes formed in the respective projecting portions 11, 12 on the rear side of the printed wiring board 3, and 91, 91,
Reference numeral 91 is a screw hole formed in a portion of the chassis 1 corresponding to the cutout portion 10 at the rear center of the printed wiring board 3.

Thus, the magnetic path members 64, 64 'have their bases 65, 65'.
Is arranged in a portion of the chassis 1 corresponding to the cutouts 13, 14 of the printed wiring board 3 so as to close the openings 88, 88 'of the chassis 1, and the mounting holes 66, 66,
(66 ', 66') inserted through screws 92, 92, ...
Is fixed to the chassis 1 by being screwed into the screw holes 89, 89, 89 ′ and 89 ′ of the chassis 1. The bobbins 47, 47 of the electromagnets 43g, 43h have wall portions 67, 67, 67 on the three sides of the magnetic path bodies 64, 64 '.
67 ', 67', 67 'are accommodated in a space surrounded by the protrusions 50, 50 so that the protrusions 50, 50 extend toward the side on which the rotation support 81 is located, and the bobbins 47, 47. Legs 53, 53, ...
Is the mounting hole 6 of the base 65, 65 'of the magnetic path body 64, 64'
, And the lower ends of the terminal pins 52, 52, ... Are formed on the protrusions 11, 12 of the printed wiring board 3, respectively. Hole 9
It is inserted through 0, 90, 90 ', 90'. Then, the magnetic path body 6 of the leg portions 53, 53, ... Of the electromagnets 43g, 43h.
The parts projecting downward through the base parts 93, 93, ... Of the base parts 4, 64 'are crimped to form a retaining head part, whereby the bobbins 47, 47 are connected to the magnetic path members 64, 6'.
4 ', and the holes 90 of the printed wiring board 3,
90, 90 ', 90' through the terminal pins 52, 52,
The lower end of ... Is soldered to a predetermined printed wiring. Further, the iron cores 49, 49 are the shaft portions 4 of the bobbins 47, 47.
4 and 44 are passed through, and the lower ends thereof are fixed by caulking to the openings 68, 68 'formed in the bases 65, 65' of the magnetic path bodies 64, 64 'at the peripheral edges of the openings. And the brake body 6
9, 69 ', the peripheral portions of the lower surfaces of the suction plates 74, 74' are wall portions 67, 67, 67, 67 ', 6 of the magnetic path bodies 64, 64'.
It is arranged so as to face the upper end surfaces of 7'and 67 ', and accommodates the terminal pin mounting portions 51, 51 of the electromagnets 43g, 43h in the openings 72, 72' of the supports 70, 70 '. Also, the pins 73, 73, 73 'and 73' of the leg portions 71, 71, 71 'and 71' are U-shaped grooves 84, 84 and 84 'and 84' of the pedestal 82 of the rotation supporting portion 81. The pressing plate 85 is superposed on the upper surface of the pedestal 82 in a state where the pressing plate 85 is placed so as to be housed inside and is arranged in this manner. The rotation support portion 81 has mounting holes 87, 87,
The screws 94, 94, 94 are passed through 87, and the screws 94, 9
4, 94 are screw holes 91, 91, 9 formed in the chassis 1.
It is screwed into 1. As a result, the pedestal 8 of the rotation support portion 81
2 and the pressing plate 85 are fixed to the chassis 1, and the pins 73, 73, 73 ', 7 of the brake bodies 64, 64' are fixed.
3'is each U-shaped groove 84, 84, 84 ', 8 of the pedestal 82.
It is rotatably held in the space formed between 4'and the lower surface of the holding plate 85. In this state, the leg portions 71, 71, 71 ', 71' of the brake bodies 64, 64 'have the cutout portions 83, 83, 83', 83 'of the rotation support portion 81.
And 86, 86, 86 ', 86' in a tiltable position.

Reference numeral 95 denotes an adjusting screw arranged at a position corresponding to a lower surface of a portion of the S reel base 19 near the outer peripheral edge of the disk portion 25 and close to a position where the friction braking mechanism 42A is provided. A flange portion 96 is formed on the chassis 1. The flange portion and an upper portion thereof project above the chassis 1, and a lower portion thereof is screwed into a screw hole 97 (see FIG. 8) formed in the chassis 1. Has been done. Therefore, the adjusting screw 95
The height of the flange portion 96 with respect to the upper surface of the chassis 1 can be adjusted by adjusting the amount of screwing into the screw hole 97.

Reference numeral 98 denotes a coil spring, the lower end of which is externally fitted to the upper portion of the adjusting screw 95 and the lower end of which is placed on the flange portion 96 of the adjusting screw.

Incidentally, 95 'is arranged at a position corresponding to the lower surface of a portion of the T reel stand 20 near the outer peripheral edge of the disk portion 25', and the lower portion thereof is screwed into a screw hole 97 'formed in the chassis 1 for adjustment. It is a screw and has a flange portion 96 '. The lower part of the coil spring 98 'is externally fitted to the adjusting screw 95'.

Thus, the tip ends of the brake arms 77, 77 'of the brake bodies 69, 69' are adjusted by the adjusting screws 95,
The upper ends of the coil springs 98 and 98 'are elastically contacted with the lower surface of the tip portion of the coil springs 98, 98'. In addition, the upper ends of the coil springs 98 and 98 'are provided on the brake arm 7.
Protrusions 79, 7 formed on the lower surface of the tip of the 7, 77 '
9'is fitted over the coil spring 98,
The displacement of 98 'is prevented. Then, in such a state, the brake bodies 69, 69 ′ have the coil springs 9 at the tip end portions of the brake arms 77, 77 ′.
When the pins 73, 73 or 73 ', 73' are pressed upward by the elastic force of 8, 98 ', the suction plates 74, 74' are rotated about the position where the pins 73, 73 or 73 ', 73' are supported by the rotation support 81. Since the brake arms 77, 77 'are urged by the turning force to rotate so as to float,
The brake shoes 80, 80 'come into pressure contact with the lower surfaces of the disk portions 25, 25' of the reel stands 19, 20.

Therefore, the friction braking mechanism 42 configured as described above is used.
In A and 42B, when each electromagnet 43g, 43h is energized, each iron core 49, 49 of each electromagnet 43g, 43h
A magnetic field is generated between the magnetic path bodies 64 and 64 'and the magnetic force of this magnetic field acts as a suction force for the suction plates 74 and 74' of the brake bodies 69 and 69 '. Therefore, the attraction plates 74, 74 'are attracted toward the electromagnets 43g, 43h, and the upper end surfaces of the iron cores 49, 49 and the magnetic path members 64, 6 are attracted.
4'walls 67, 67, 67, 67 ', 67', 6
7'is attracted to the upper end surface of each of the brake arms 77, 77 ', so that the tips of the brake arms 77, 77' are coil springs 98, 9
The brake shoes 80, 80 'are displaced downwards against the elastic force of 8', and the brake shoes 80, 80 'are moved to the disk portions 25, 2 of the reel stands 19, 20.
The state of being pressed against the lower surface of 5'is released. That is, the brake on the reel stands 19 and 20 is released. When the power supply to the electromagnets 43g and 43h is cut off,
Since the magnetic field generated there disappears, the brake body 6
9, 69 'are rotated by the elastic force of the coil springs 98, 98', and the brake shoes 80, 80 'are pressed against the undersides of the disk portions 25, 25' of the reel stands 19, 20 to make the reel stand 19, Brakes 20. The brake control for the S reel base 19 and the T reel base 20 by the friction braking mechanisms 42A and 42B will be described in detail later.

Next, the electromagnetic braking mechanism 41 and the friction braking mechanism 42 described above.
An example of control for braking the reel bases 19 and 20 by using will be described in detail according to a specific control circuit.

FIG. 9 shows an example of the control circuit. In the figure, M ₁ , M ₂ and M ₃ indicate the electromagnets 43a, 43b and 43c of the electromagnetic braking mechanism 41A on the S reel stand 19 side, and M ₄ , M ₅ and M ₆ indicate on the T reel stand 20 side. The electromagnets 43d, 43e, 43f of the electromagnetic braking mechanism 41B are shown. M ₇ is an electromagnet 43g for operating the brake lever 77 of the S-reel base 19 side friction braking mechanism 42A, and M ₈ is a brake arm of the T-reel base 20 side friction braking mechanism 42B. It shows an electromagnet 43h for operating 77 '. The electromagnets M ₁ , M ₂ and M ₃ associated with the S reel base 19 are connected to the relay L ₁
Switches SW ₁ , SW ₂ , S whose contacts can be switched by
The switch circuit composed of W ₃ , SW ₄ and SW ₅ is adapted to switch the mutual connection state between the normal connection and the serial connection, and in the same manner, it is related to the T reel stand 20. The electromagnets M ₄ , M ₅ and M ₆ are also switches SW ₆ , S whose contacts can be switched by the relay L ₁ .
A switch circuit composed of W ₇ , SW ₈ and SW _{9 can} switch the connection state between the parallel connection and the series connection. Similarly, the electromagnets M ₇ and M _{8 of} the friction brake mechanisms 42A and 42B are connected in parallel by a switch circuit composed of switches SW ₁₀ , SW ₁₁ and SW ₁₂ whose contacts can be switched by a relay L ₂ . The connection can be switched to the series connection.

T _{1 to} T ₈ are input terminals for trigger signals, and the input terminals T _{1 to} T _{8 for} these trigger signals are connected to appropriate input / output ports of a microcomputer (not shown).

A trigger signal is input to the trigger signal input terminal T ₁ to excite the electromagnets M _{1 to} M ₃ . That is, Tr ₁ is a trigger transistor whose base is connected to the docking signal input terminal T ₁ , PTr ₁ is a power transistor whose base is connected to the collector of the trigger transistor Tr ₁ , and a high level trigger signal from the input terminal T _1. Is input, the trigger transistor Tr ₁ is activated, whereby a collector current flows in the power transistor PTr ₁ and the electromagnets M _{1 to} M ₃ are excited.

The trigger signal input terminal T ₂ trigger signal for energizing the electromagnets M ₄ ~M ₆ mentioned above are input. That is, Tr ₂
Is a trigger transistor whose base is connected to the Driga signal input terminal T ₂ , PTr ₂ is a power transistor whose base is connected to the collector of the trigger transistor Tr ₂ , and when the trigger signal is input from the input terminal T ₂ , the trigger transistor Tr ₂ is activated, which causes a collector current to flow through the power transistor PTr ₂ and causes the electromagnet M _{4 to} move.
~ M ₆ is excited.

Trigger signals for exciting the electromagnets M ₇ and M ₈ described above are input to the trigger signal input terminals T _{3 to} T ₅ , of which T ₃ is between each electromagnet M ₇ and M ₈ and the positive electrode of the power supply. a trigger signal for opening and closing a circuit is input, also, T ₄
For opening and closing the circuit between the electromagnet M ₇ on the S reel stand 19 side and the negative pole of the power supply, at T ₅ , for opening and closing the circuit between the electromagnet M ₈ on the T reel stand 20 side and the negative pole of the power supply. A trigger signal is input. That is, Tr ₃ is a trigger transistor whose base is connected to the trigger signal input terminal T ₃ , PTr ₃ is a power transistor whose base is connected to the collector of the trigger transistor Tr ₃ , and the trigger signal input terminal T 3
_{When a} high-level trigger signal is input from ₃ , the trigger transistor Tr ₃ is activated, whereby a collector current flows through the power transistor PTr ₃ and the electromagnets M ₇ and M
₈ and the positive electrode (+) of the power supply close. Then, Tr ₄ is a trigger transistor, and its collector is a switch S.
It is connected to the electromagnet M ₇ through W ₁₀ , and when a high-level trigger signal is input from the trigger signal input terminal T ₄ , the trigger transistor Tr ₄ enters a state in which a collector current flows. Incidentally, when the contact of the switch SW ₁₀ is switched to the state indicated by the two-dot chain line, control of the electromagnet M ₇ is performed only by the trigger signal T ₃ described above regardless of the trigger signal T _4. Tr ₅ is a trigger transistor, the collector of which is connected to the electromagnet M ₈ via the switch SW ₁₂ , and when the trigger signal is input from the trigger signal input terminal T _{5, the} collector current of the trigger transistor Tr ₅ changes. It will be in a flowing state. Incidentally, when the contact of the switch SW ₁₂ is switched to the state indicated by the two-dot chain line, control of the electromagnet M8 is performed by the trigger signal T ₃ described above regardless of the trigger signal T _5.

The trigger signal input terminal T ₆ is supplied with a dragger signal for exciting the relay L ₁ described above. That is, Tr ₆ has a trigger transistor whose base is connected to the trigger signal input terminal T ₆ , and PTr ₄ has a base whose trigger transistor Tr ₆
A power transistor connected to the collector of the trigger signal at a high level from the trigger signal input terminal T ₆ is input to operate the trigger transistor Tr _6, which becomes the collector current flows through the power transistor PTr ₄ by Therefore, this power transistor PTr ₄
The relay L ₁ connected to the collector of is excited. Therefore, when the relay L ₁ is excited, the switches SW _{1 to} SW ₅
Also, the contacts of the switches SW _{6 to} SW ₉ are switched from the state shown by the solid line in the figure to the state shown by the two-dot chain line. Then, from the state in which the electromagnets M _{1 to} M ₃ were connected in parallel to each other, the power transistor PTr ₁ → electromagnet M ₃ → SW
₄ → electromagnet M ₂ → switch SW ₂ → electromagnet M ₁ → switch S
W ₁ → switch SW ₅ → the negative pole of the power supply is connected in series, and the electromagnets M _{4 to} M ₆ are also similarly connected from the previous parallel connection to the power transistor PTr ₂ → Electromagnet M ₆ → Switch SW ₉
→ electromagnet M ₅ → switch SW ₇ → electromagnet M ₄ → switch S
W ₁₃ → the negative electrode of the power supply is connected to each other in series. Thus, the electromagnets M _{1 to} M ₃ and M _{4 to} M ₆
Are connected in series with each other, the current value flowing through the coils of the electromagnets M _{1 to} M ₆ becomes small due to the voltage drop, which reduces the magnetic force of the magnetic field formed by the electromagnets M _{1 to} M ₃ and M _{4 to} M _6. It will be lowered. And the electromagnet M ₁
~ M ₃ and M ₄ ~ M ₆ decrease in magnetic force, as described above,
Suction plate 30 or 3 provided on each reel stand 19 or 20
Since it acts as a reduction in the attraction force for 0 ', this acts as a change in the braking force for the reel stands 19 and 20. That is, by the connection state of the electromagnet M ₁ ~M ₃ or M ₄ ~M ₆ is changed, it is this to moderate the braking force applied to the reel base 19 and 20. Then, by adjusting the braking force on the reel stands 19 and 20,
Since it is possible to adjust the braking force with respect to the rotation of the tape reel that is rotated by being engaged with the reel stands 19 and 20, it is possible to control the tension applied to the tape to an optimum value.

A trigger signal for canceling the excitation of the relay L ₂ is input to the trigger signal input terminal T ₇ . That is, Tr ₇
Is a trigger transistor, and PTr ₅ is a power transistor whose base is connected to the collector of the trigger transistor Tr _{7. When} the trigger signal T ₇ is not input, the trigger transistor does not operate. Therefore, a collector current flows through the power transistor PTr _5. Therefore, the relay L ₂ causes the contacts of the switches SW _{10 to} SW _{13 to be in} the state shown by the solid line in the figure, but when the trigger signal T ₇ is input, the trigger transistor Tr ₇ is activated, which causes the power transistor. The collector current of PTr ₅ stops flowing because the potential on the base side becomes low. Therefore, when the trigger signal T ₇ is input, the excitation of the relay L ₂ is released, whereby the contacts of the switches SW _{10 to} SW ₁₃ are switched to the state shown by the chain double-dashed line in the figure. That is, in this state (the state where the trigger signal T ₇ is input), the electromagnets M ₇ and M ₈ are connected to the positive electrode of the power source → the power transistor PT.
r ₃ → electromagnet M ₈ → switch SW ₁₂ → electromagnet M ₇ → switch SW ₁₀ → negative pole of the power source are connected in series.
When the electromagnets M ₇ and M ₈ are thus connected in series with each other, the magnetic force of the magnetic field formed by the electromagnets M ₇ and M ₈ is reduced. However, the above-mentioned brake body 6
Brake arms 77, 77 'of 9, 69' are mounted on reel stand 1
A spring 98 that urges elastically toward the 9 and 20 sides,
The magnetic force required to attract the suction plates 74, 74 'against the elastic force of 98' is the initial attraction, that is, the suction plates 74, 7 '.
4'is attracted to the iron cores 49, 49 of the electromagnets 43g, 43h and the upper end surfaces of the magnetic path bodies 64, 64, 64, 64 ', 64', 64 '. However, after once adsorbed, the adsorbed state can be sufficiently maintained with a relatively small suction force. That is, the trigger signal T ₇ is input after the brakes applied to the reel bases 19 and 20 by the brake arms 77 and 77 'are released.

The switches SW ₁₄ and SW ₁₅ are connected to the trigger signal input terminal T _8.
A trigger signal for canceling the excitation of the relay L ₃ for switching the contact of is input. That is, SW ₁₄ is a change-over switch connected between the emitter of the power transistor PTr ₁ and the positive electrode of the power source, and one change-over terminal is the resistor R _24.
Is connected to the positive electrode of the power source through the electromagnet M ₁
The amount of current flowing through M ₃ to M ₃ is adjusted by switching the contact of the switch SW ₁₄ , so that the magnetic forces of the electromagnets M _{1 to} M ₃ can be adjusted. SW ₁₅ is the power transistor PT
A switching switch connected between the emitter of r ₂ and the positive electrode of the power supply, one switching terminal of which is connected to the positive electrode of the power supply via a resistor R ₂₅ , and the current flowing through the electromagnets M _{4 to} M ₆ the amount is moderated by switching the contacts of the switch SW _15, thereby being enabled to increase or decrease the magnetic force of the electromagnet M ₄ ~M _6. The relay L ₃ is a relay for switching the contacts of the switches SW ₁₄ and SW ₁₅ , and when energized, the contacts of the switch SW ₁₅ are switched to the state shown by the solid line in the figure. And T
r ₈ is a trigger transistor, PTr ₆ is a power transistor whose base is connected to the collector of the trigger transistor Tr ₈ , and when the trigger signal T ₈ is not input, the trigger transistor Tr ₈ does not operate and the power transistor PTr ₆ and a collector current flows in, whereby although the relay L ₃ is a state of being energized is maintained, trigger the transistor Tr ₈ is activated when the trigger signal T ₈ are input, whereby the power transistor PTr ₆ base side The collector current does not flow because the potential of is low. Therefore, when the trigger signal T ₈ is input, the excitation of the relay L ₃ is released, and the contacts of the switches SW ₁₄ and SW ₁₅ are switched to the state shown by the chain double-dashed line in the figure.

According to the control circuit shown in FIG. 9, the electromagnets M _{1 to} M ₃ on the S reel base 19 side of the electromagnetic braking mechanism 41 described above are input by the trigger signal T ₁ and the electromagnet M ₄ on the T reel base 20 side. .About.M ₆ are respectively excited by the input of the trigger signal T ₂ , and the magnetic forces of these electromagnets are strengthened by the input of the trigger signal T ₈ and weakened by the input of the trigger signal T ₆ . On the other hand, the electromagnet M ₇ in the friction braking mechanism 42A on the S reel base 19 side of the friction braking mechanism 42 described above receives the trigger signals T ₃ and T ₄ , and also the T reel base 2
The electromagnet M ₈ in the friction braking mechanism 42B on the 0 side is excited by the input of the trigger signals T ₃ and T ₅ , and the magnetic force is weakened by the input of the trigger signal T ₇ .

By controlling the both braking mechanisms 41 and 42 by the control circuit configured as described above, it is possible to freely control the braking of the rotation of each tape reel of the cassette which is engaged with the reel stands 19 and 20 and is rotated. As a result, the tape tension suitable for each mode for the tape can be obtained. The control input of the trigger signal to Doriga signal input terminal T ₁ through T ₈ described above is performed by the microcomputer.

Therefore, next, some specific examples of control of the tape tension and the brake will be shown.

(1) In FWD (and RED) mode. In this mode, the tape runs at a low speed toward the T reel side. The trigger signals at this time are T ₁ , T ₂ , T ₃ , T ₆ , T
₇ is ON, T ₄ , T ₅ , and T ₈ are OFF. That is, since the trigger signals T ₁ and T ₆ are turned on and the trigger signal T ₈ is turned off, the electromagnets M _{1 to} M ₃ on the S reel base 19 side are connected in series and via the resistor R _24. An electric current is supplied to generate a weak magnetic force, so that a weak back tension is applied to the S reel and the trigger signal T
_When SW ₇ is turned on, SW ₁₃ is brought into the state shown by the chain double-dashed line in the figure, so that the electromagnets M ₄ to
Not energized to M _6, therefore no electromagnetic braking force against T reel base 20. Also, the trigger signals T ₃ and T ₇ are O
By being turned on, the electromagnets M ₇ and M ₈ related to the brake bodies 69, 69 ′ are energized in a state where they are connected in series with each other so that the brake arms 77, 77 ′ are connected to the reel bases 1.
Hold the brake for 9 and 20 in the released state.

(2) In RVS mode. In this mode, the tape moves slowly from the T reel side to the S reel side (reverse rotation).
Be driven. The trigger signals at this time are T ₂ , T ₃ , T ₄ ,
T _5, T ₆ is _{ON, T 1, T 7,} T 8 is turned OFF. That is, the trigger signals T ₂ and T ₆ are ON, and the trigger signal T ₈ is OF
By being F, the electromagnet M ₄ on the T reel stand 20 side
M ₆ is supplied with current through the resistor R _{25 in} a state of being connected in series, and a weak magnetic force is generated, so that a weak back tension is applied to the T reel and the trigger signal T ₁ is generated.
Is turned off, the electromagnets M _{1 to} M ₃ on the side of the S reel base 19 are not energized, so that no electromagnetic braking force is applied to the S reel. The control state for the brake levers 77 and 77 'in the RVS mode is
When the trigger signals T ₃ , T ₄ and T ₅ are turned on, the brake is released.

(3) In the CUE mode, in this mode, the tape runs at the medium speed from the S reel side toward the T reel side. The trigger signals at this time are T ₁ , T ₂ , T ₃ , T ₆ , T
₇ and T ₈ are ON, and T ₄ and T ₅ are OFF. That is, when the trigger signals T ₁ , T ₆ and T ₈ are turned on, the electromagnet M ₁
.. M ₃ are connected in series with each other, a current is supplied without passing through the resistor R ₂₄ , so that a medium magnetic force is generated. Therefore, a medium back tension is applied to the S reel and the trigger signal T 3 is generated. _{Since 7} is turned on, electromagnet M ₄
~ M ₆ is not energized, and therefore no electromagnetic braking force is applied to the T reel base 20. The control state for the brake arms 77, 77 'in this mode is the same as that in the FWD and REC modes of the mode (1) described above.

(4) In REV mode. In this mode, the tape is run at medium speed from the T reel side toward the S reel side (toward the reverse direction). Each trigger signal at this time is
T ₂ , T ₃ , T ₄ , T ₅ , T ₆ , T ₈ are ON, T ₁ , T ₇ are OF
Let it be F. That is, when the trigger signals T ₂ , T ₆ , and T ₈ are turned on, the electromagnets M _{4 to} M ₆ are connected in series and the resistance R ₂₅
Since the current is supplied without passing through the T reel, a moderate back tension is applied to the T reel and the trigger signal T
_{Since 1} is turned off, the electromagnets M _{1 to} M ₃ are not energized, so that no electromagnetic braking force is applied to the S reel base 19. Incidentally, the brake arm 77 in this mode,
The control state for 77 'is the same as that in the RVS mode of (2) described above.

(5) When switching from the FF mode to the STOP mode, the trigger signal T ₂ is turned off and the trigger signal T ₁
Is turned on (T ₆ and T ₈ are turned on or off as necessary to adjust the magnetic force), and the trigger signal T ₃ is turned off while the tape is running at high speed while applying back tension only to the S reel. The trigger signal T ₆ is turned off and the trigger signals T ₂ and T ₈ are turned on before the mechanical brake is applied.
S reel stand 19 and T reel stand 20
It is conceivable to generate a strong magnetic force with respect to the reel bases 19 and 20 and thereby apply a large electromagnetic braking force. That is, the rotation speed of the reel bases 19 and 20 is reduced by the electromagnetic braking force, and then the trigger signal T ₃ is turned off.
If the reel bases 19 and 20 are locked by applying a mechanical brake with the brake arms 77 and 77 'after the F, the rotation of the tape reel can be smoothly stopped without giving an abnormal tension to the tape. it can. The control for applying such a brake can be applied to the control for switching to the STOP mode in the REW mode and other modes.

(6) Then, the reel stand 19 by the friction braking mechanism 42,
The timing of braking on 20 can also be controlled very conveniently. For example, when switching to the STOP mode in the FF mode, the trigger signal T ₄ is made to precede the trigger signal T ₅ by a moment and turned off.
That is, the electromagnet M ₇ precedes the electromagnet M _{8 for} a moment to release the excitation. By doing this, the S reel can brake before the T reel,
It is possible to reliably prevent the situation where the tape running at high speed sags or is excessively fed. And, of course, the control of the timing when applying such a brake is not limited to the above-mentioned FF mode, but may be performed from the REW mode or other modes to the STOP mode or P
It can also be applied to control when switching to the AUSE mode.

EFFECTS OF THE INVENTION As is apparent from the above description, in the braking device of the present invention, the first one is the first suction plate made of a magnetic body provided in each of the two rotating bodies, and the two rotating bodies. An electromagnetic braking mechanism including an electromagnet for electromagnetically attracting the first attraction plate, the terminal pins of which are connected to a printed wiring board disposed on a chassis supporting the body, and a part of the two rotating bodies are separated from each other. The height with respect to the printed wiring board, which rotates integrally with the friction member provided so as to be able to contact and the arm to which the friction member is fixed, is substantially equal to the heights of the printed wiring board and the first suction plate. A friction braking mechanism including a second suction plate and an electromagnet that electromagnetically attracts the second suction plate is provided. When the tape is fed and wound by the two rotating bodies, the electromagnetic force is applied in the tape running mode. Using a braking mechanism,
When shifting to the tape stop mode, the electromagnetic braking mechanism and the friction braking mechanism are used in combination, and the second one is rotatably driven by mounting a reel for supplying and winding the tape. An electromagnetic braking mechanism including a plate-shaped first suction plate made of a magnetic material and integrally provided on the reel stand, and a plurality of electromagnets arranged to face the first suction plate, and a tape. A friction member provided so as to be separable from and partly attached to a part of a reel base that is rotationally driven with a reel that supplies and winds is placed, and the friction member is moved in a direction of separating from the part of the reel base. And a friction braking mechanism including a pair of electromagnets, and by controlling the current flowing through a coil wound around the electromagnets of the electromagnetic braking mechanism, the running torque of the tape is normal and the rotational torque of the reel is high. Switch control, and And a pair of electromagnets for moving the friction members on the supply and take-up sides are switched to be connected in series when the tape is moved in the forward direction from the reel to the take-up reel. .

Therefore, in the control device of the present invention, the braking control for the rotating body that supplies and winds the tape is performed by using both electromagnetic braking performed without contact with the rotating body and friction braking performed with frictional contact. Since it is possible to perform this, it is possible to apply stop braking (brake) according to the rotation speed of the rotating body by freely selecting or combining both of these braking means according to the rotation speed of the rotating body. At the same time, good stop braking can be performed in a short time.

Further, in the braking device of the present invention, since the suction plate of the electromagnetic braking mechanism and the suction plate of the friction braking mechanism have the same height from the printed wiring board to which the terminal pin of the electromagnet is connected,
The electromagnet of the electromagnetic braking mechanism and the electromagnet of the friction braking mechanism can be made common, or the supply and take-up braking mechanism can be used when the tape is moved from the supply reel to the take-up reel in the forward direction. Since the electromagnets for driving the tape are switched in series, the power consumption of the friction braking mechanism can be reduced when the tape is running in the forward direction.

Further, in the above-described embodiment, the electromagnets in the electromagnetic braking mechanism and the electromagnets in the friction braking mechanism have exactly the same structure, but by doing so, the braking device can be manufactured at low cost. . Further, similarly, in the above-described embodiment, the terminals of each electromagnet are formed in a pin type so as to be inserted into the printed wiring board similarly to the usual electronic circuit parts, so that the assembling work of the braking device can be automated. Will be easier.

In the embodiment described above, the suction plate mounted on the reel stand side of the electromagnetic braking mechanism is fixedly provided on the lower surface of the reel stand. However, in some cases, the suction plate provided on the reel stand side may be It may be possible to mount the reel base so as to be movable in the axial direction. For example,
The suction plate is supported by an appropriate supporting means such as a guide pin so as to be movable in the axial direction of the reel table on the lower surface side of the reel table, and is constantly ejected by an appropriate elastic means toward the lower surface of the reel table. If the magnetic force is applied, braking in the non-contact state and braking in the contact state can be performed by controlling the magnetic attraction force of the electromagnetic braking mechanism.

Further, the friction braking mechanism may be the one shown in FIG. 1 other than that shown in the above embodiment.

In the above-mentioned embodiment, the braking device of the present invention is
An example of application to a reel stand braking device in TR has been shown, but the braking device of the present invention is not limited to this example, and can be applied to braking devices for various rotating bodies.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part showing an example of a conventional rotating body braking device, and FIGS. 2 to 9 show an example of an embodiment in which the braking device of the present invention is applied to a reel stand braking device in a VTR. FIG. 2 is a plan view of the entire braking device, FIG. 3 is a perspective view of an essential part showing only the electromagnetic braking mechanism of the reel stand in a partially disassembled state, and FIG. 4 is a partially exploded view showing only the friction braking mechanism of the reel stand. FIG. 5 is a perspective view of an essential part, FIG. 5 is a perspective view of an electromagnet, FIG. 6 is a sectional view taken along the line AA in FIG. 2, and FIG. 7 is B in FIG.
-B is a sectional view taken along the line B, FIG. 8 is a sectional view taken along the line CC in FIG. 2, and FIG. 9 is a circuit diagram showing an example of a control circuit for controlling the electromagnetic braking mechanism and the friction braking mechanism. . Explanation of reference numerals 1 ... Chassis, 3 ... Printed wiring board, 19, 20
... Rotating body (reel stand), 30, 30 '... First suction plate, 41 ... Electromagnetic braking mechanism, 42 ... Friction braking mechanism, 4
3 ... electromagnet, 48 ... coil, 52 ... terminal pin, 7
4, 74 '... second suction plate, 77, 77' ... arm, 80, 80 '... friction member

Claims (2)

[Claims] 1. A first suction plate made of a magnetic material provided in each of two rotating bodies, and a terminal pin thereof connected to a printed wiring board arranged on a chassis supporting the two rotating bodies. An electromagnetic braking mechanism including an electromagnet that electromagnetically attracts the first attraction plate, a friction member that is detachably attached to a part of the two rotating bodies, and an arm to which the friction member is fixed. A second suction plate having a height with respect to the rotating printed wiring board substantially equal to the heights of the printed wiring board and the first suction plate, and an electromagnet for electromagnetically attracting the second suction plate are provided. And a friction braking mechanism, wherein the electromagnetic braking mechanism is used in the tape running mode when the tape is fed and wound by the two rotating bodies, and the electromagnetic braking mechanism and the friction braking are used when shifting to the tape stop mode. Together with the mechanism Braking device, characterized in that. 2. A plate-shaped first suction plate made of a magnetic material, which is integrally provided on a reel base that is rotationally driven by mounting a reel for supplying and winding a tape, and the first suction. An electromagnetic braking mechanism consisting of a plurality of electromagnets arranged facing the plate, and a reel stand that rotates and drives the reels that supply and wind the tape can be attached to and detached from each part. A friction braking mechanism including a provided friction member and a pair of electromagnets that move the friction member away from a part of the reel stand, and a coil wound around the electromagnet of the electromagnetic braking mechanism. By controlling the electric current flowing through the tape, the rotational torque of the reel is controlled to be switched depending on whether the tape traveling speed is normal or high,
The present invention is configured so that a pair of electromagnets that move the friction members on the supply and take-up sides are switched to be connected in series when the mode is changed to a mode in which the tape is run in the forward direction from the supply reel to the take-up reel. And a reel rotation control device.