JPH0652599A - Reel base brake for vtr - Google Patents

Abstract

PURPOSE:To manufacture a single low-cost structure and to eliminate an unnecessary load at the time of forward feeding by providing a braking pawl for braking an output side gear of a winding reel base, and a switching lever of the pawl. CONSTITUTION:A reel base brake 40 is arranged to be engaged with or separably from a brake clutch 50 to be engaged with an output side gear 28 of a winding reel base 24 and a ratchet gear 56 of the clutch 50. The pawl 41 brakes the gear 28 through the clutch 50 at the time of engaging. A brake releasing lever 42 releases an engaging state of the pawl 41 with the gear 56 of the clutch 50 of the pawl 41. A brake switching lever 43 is movably engaged with a columnar part 41d of a base end of the pawl 41 and so switched as to be engaged with or separated from the gear 56 of the clutch 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reel base brake device for a VTR (video tape recorder) for braking a take-up reel base rotatably supported on a so-called linear skating movable chassis (LS chassis).

[0002]

2. Description of the Related Art Rewinding of a magnetic tape of a VTR (R
At the time of EW), a reel stand brake device is provided which applies an appropriate load to the take-up reel stand to prevent the excess tape from being pulled out due to idling of the take-up reel stand. FWD (forward) running and REW (rewinding) of the above magnetic tape
In a VTR of a system in which RVS (reverse reproduction) traveling of REVIEW (rewinding reproduction) is switched only by switching the rotational direction of a motor for driving the magnetic tape, back tension is applied to the magnetic tape during RVS traveling of the magnetic tape. For this reason, there is a reel stand brake device for braking the take-up reel stand shown in FIGS. 11 and 12.

In a VTR reel stand brake device 100 shown in FIG. 11, a take-up reel stand 10 having a torque limiter function is rotatably mounted on a fixed chassis 101.
The second input gear 102a is always braked by the brake lever 103. Further, in the reel stand brake device 100 'of the VTR shown in FIG. 12, the output side gear 10 of the take-up reel stand 102' having a torque limiter function rotatably attached to the fixed chassis 101.
The brake lever 103 applies a brake to 2b. In FIGS. 11 and 12, reference numeral 104 is a swing gear. The swing gear 104 swings to swing its head according to the rotation direction of a motor (not shown) as a drive source,
Each reel base is driven by meshing with the input side gear 102a of the take-up reel base 102 or the input side gear of a supply reel base (not shown). Then, the swing gear 104
Is engaged with the input side gear of each supply reel stand by each brake lever 103 during each RVS running.
The brake is applied to 2, 102 'to give back tension to the magnetic tape.

[0004]

However, in the above reel stand brake device 100, the take-up reel stand 102 is used.
Since the input side gear 102a is always braked by the brake lever 103, the brake load of the take-up reel stand 102 is FWD running (the swing gear 104 is the input side gear of the take-up reel stand 102). 10
2a), the power of the motor increases as it is, and the power consumption increases.
There is a drawback that the brake torque cannot be made larger than the torque of the torque limiter of No.2. Further, in the other reel stand brake device 100 ', the take-up reel stand 102' is provided.
Since the one-way clutch mechanism 105 having a complicated structure must be disposed on the output side gear 102b side of the above, there is a disadvantage that the cost is increased.

Therefore, the present invention provides a reel base brake device for a VTR which can be manufactured at a low cost with a simple structure and does not generate an unnecessary load during FWD traveling.

[0006]

A movable chassis having a supply reel base and a take-up reel base rotatably mounted on a fixed chassis having a rotary head drum rotatably mounted thereon is reciprocally movable. In the reel stand brake device of the VTR in which the swinging gear that swings and meshes with one of the stand and the take-up reel stand to drive the one reel stand is swingably supported on the fixed chassis, A brake switching lever is rotatably supported on the chassis, and the brake is turned on / off with respect to one of the reel bases according to the positional relationship between the brake switching lever and the swing gear that approaches and separates from the brake switching lever. It is configured as follows.

[0007]

Since the one-way clutch mechanism is not used as in the prior art and only the simple mechanism is used, the reel stand brake device of the VTR can be manufactured at low cost. Further, no unnecessary load is generated during the FWD running of the VTR tape.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

2 to 4, reference numeral 1 denotes a VTR, which allows the movable chassis 20 to be reciprocally slidably moved (so-called linear skating) by a drive mechanism (not shown) with respect to the fixed chassis 10 via a plurality of support pins 2 and the like. It is provided.
That is, the VTR 1 includes a fixed chassis 10 in which a rotary head drum 3 is rotatably driven by a motor (not shown) and a support shaft 2 standing upright in a pair of recesses 20a, 20a.
A movable chassis 20 that rotatably supports a supply reel base 23 and a take-up reel base 24 is provided on the first and second units 22 and 22. Then, as shown in FIGS. 2 and 3, the tape cassette 30 mounted on the supply reel base 23 and the take-up reel base 24 of the movable chassis 20 via a cassette holder (not shown) is fixed together with the movable chassis 20. By performing linear skating on the chassis 10, the rotary head drum 3 on the fixed chassis 10 is taken into the opening 30 a of the tape cassette 30. A magnetic tape 31 is provided in the opening 30a of the tape cassette 30.
Tape guides 4 on the supply and take-up sides for pulling out the tape
5 is supposed to enter. The tape guides 4 and 5 on the supply side and the take-up side are reciprocally moved around the rotary head drum 3 by a loading mechanism (not shown) including a loading motor provided on the fixed chassis 10 side. The magnetic tape 31 is loaded or unloaded by pulling out or winding up the magnetic tape 31 from the opening 30 a of the opening 30.

A support shaft 11 is provided in a protruding manner at a position facing the rotary head drum 3 at the center of one end of the fixed chassis 10. As shown in FIG. 4, a drive pulley 12 is rotatably supported on the lower side of the support shaft 11. A belt-shaped timing belt 7 is stretched between the drive pulley 12 and a driven pulley (not shown) that is rotated by a capstan motor 6 provided on the fixed chassis 10 side. Also,
An oscillating plate 13 is rotatably supported on the upper end of the support shaft 11, and a swing gear 14 is rotatably supported at the approximate center of the oscillating plate 13. The swing gear 14 meshes with a tooth portion 12a integrally formed on the upper portion of the drive pulley 12, and the swing gear 14 is rotated forward and backward by the capstan motor 6 so that the swing gear 14 is a gear portion of the supply reel base 23. 23a and the input-side gear 27 of the take-up reel stand 24 are swung and meshed to rotate the reel stands 23, 24. Further, as shown in FIG. 5, the support shaft 15 is provided at a position substantially opposite to the central capstan motor 6 on the fixed chassis 10.
A cam gear (cam) 16 is rotatably supported via. The cam gear 16 is driven by the loading motor, and the outer peripheral surface of the lower portion thereof has a convex surface 16b on a part thereof.
Is a cam surface 16a having a. This cam surface 16a
A base end portion 18a of a substantially doglegged lever 18 rotatably supported on the fixed chassis 10 via a support shaft 17 is in contact with the fixed chassis 10. The central portion 18b of the lever 18 and the fixed chassis 1
A tension coil spring 19 is interposed between 0 and 0, and its tip portion 18c faces the back surface side of the movable chassis 20. The base end of the rocking plate 13 has a cam surface 1 of an inverted Ω shape.
It is 3a.

As shown in FIG. 1, the take-up reel stand 2
Reference numeral 4 denotes a disc 25 rotatably supported by the support shaft 22, an input side gear 27 that rotates together with the disc 25 via a friction member 26a, and a compression coil spring 26b between the input side gear 27. An output side gear 28 that rotates together with the input side gear 27 through a spring, a spring retainer 29 that also serves as a claw portion that is inserted and locked in the reel hole of the tape cassette 30, and the like are provided. The coil spring 26b and the like function as a torque limiter. The heights of the input gear 27 and the swing gear 14 are at the same position, and the input gear 27 is driven by the swing gear 14.

As shown in FIGS. 2 and 4, the movable chassis 2
In the corner portion on the back side near the take-up reel stand 24 of 0,
Take-up reel stand 24 when the RVS of the magnetic tape 31 is running
A reel stand braking device 40 for applying a brake to is provided. The reel stand brake device 40 is arranged so as to mesh with and separate from a brake clutch (brake limiter) 50 that meshes with the output side gear 28 of the take-up reel stand 24 and a ratchet gear 56 of the brake clutch 50. When engaged, a brake claw 41 that brakes the output side gear 28 of the take-up reel base 24 via the brake limiter 50, and a brake release that releases the meshing state of the brake claw 41 with the ratchet gear 56 of the brake limiter 50. A lever 42 and a brake switching lever 43 that is loosely fitted to the base end portion of the brake pawl 41 and that switches so that the brake pawl 41 meshes with and separates from the ratchet gear 56 of the brake limiter 50.

The brake pawl 41 is provided on the movable chassis 20.
It is rotatably supported via a support shaft 44 protruding from the back side of the ratchet, and the claw portion 41a at the tip thereof is locked (engaged) with the ratchet gear 56 of the brake limiter 50 and can be separated. The brake release lever 42 is rotatably supported via a support shaft 45 that is provided on the back side of the movable chassis 20 and is inserted into the first hole 41b of the brake pawl 41. The brake release lever 42 is formed in a V shape, and its one end 42a and the movable chassis 20 are connected to each other.
While a tension coil spring 46 is interposed between
The other end 42b of the brake release lever 42 has the brake pawl 4
It is loosely fitted in the first second hole 41c. One end 42a side of the brake release lever 42 is on the fixed chassis 10 side.
The cam surface 16a of the cam gear 16 rotatably supported on the rotating lever 18 allows the rotating lever 18 to be pressed and separated. Further, the brake switching lever 43 is rotatably supported by a support shaft 47 protruding from the rear surface of the rotating chassis 20. The brake switching lever 43 is formed in a V shape, and a recessed portion 43a formed at one end side thereof is loosely fitted with a cylindrical portion 41d integrally formed at the base end portion of the brake pawl 41. In addition, a pair of cylindrical portions 4 formed integrally on both ends of the brake switching lever 43.
Numerals 3b and 43b are capable of coming into contact with and separating from a cam surface 13a of a rocking plate 13 which rotatably supports the swing gear 14.

The brake clutch 50 is rotatably supported by a disc 52 rotatably supported by a support shaft 51 provided on the back side of the movable chassis 20 and a central cylindrical portion 52a of the disc 52. , A gear 53 meshing with the output gear 28 of the take-up reel stand 24, a friction member 54 interposed between the gear 53 and the disc 52, and a compression coil spring 55 interposed between the brake 53 and the brake pawl. 41 is a ratchet gear 56 that is locked (engaged) and separated. White / black marks 52b, 52b for rotation detection are provided on the surface of the circular plate 52 on the fixed chassis 10 side, and the brake clutch 50 of the brake clutch 50 is provided on the fixed chassis 10 side facing the respective marks 52b. A photocoupler (position detection sensor) 8 having a light emitting element 8a for detecting the rotational position and a light receiving element 8b is attached. In addition, the friction member 54
Thus, the gear 53 and the ratchet gear 56 are relatively rotated with a constant torque.

According to the reel stand brake device 40 of the VTR 1 of the above embodiment, the tape guides 4 and 5 are loaded at the time of unloading shown in FIG. 6 and when the sliding of the movable chassis 20 shown in FIG. 7 is completed. In the middle of the process and during the unloading process, the brake pawl 41 is pulled and biased by the tension coil spring 46, and the ratchet gear 5 of the brake clutch 50 is pulled by the brake release lever 42.
The magnetic tape 31 is held in a state of being separated from the magnetic tape 6, so that it does not hinder the drawing and winding of the magnetic tape 31.

Further, in the state where the loading of the magnetic tape 31 shown in FIG. 8 is completed and stopped (STOP),
The brake release lever 42 is rotated (swinged) by the cam surface 16 a of the cam gear 16 via the lever 18 in the direction opposite to the tension direction of the tension coil spring 46, and the brake pawl 41 is moved to the ratchet gear 5 of the brake clutch 50.
Engage with 6. This prevents the magnetic tape 31 from loosening.

Further, the FWD (recording,
During traveling (playback, fast forward, etc.) / RVS (reverse rotation), the brake release lever 42 is located at an intermediate position between the unloading shown in FIG. 6 and the STOP shown in FIG. 8 due to the convex surface 16b of the cam surface 16a of the cam gear 16. Then, the brake claw 41 can be freely rotated. When the loading is completed, the brake switching lever 43
The oscillating gear 14 approaches, and the brake switching lever 43 rotates in conjunction with the movement of the oscillating plate 13 that rotatably supports the oscillating gear 14. As a result, during the FWD traveling shown in FIG.
Take-up reel stand 2 separated from the ratchet gear 56 of 0
The brake of No. 4 is released, and the brake claw 41 meshes with the ratchet gear 56 of the brake clutch 50 during the RVS running shown in FIG. 10, and the friction torque of the brake clutch 50 becomes the brake torque, which creates the back tension during the RVS running.

As described above, according to the reel base brake device 40 of the VIR 1, since it is not necessary to use the one-way clutch mechanism for the take-up reel base as in the conventional case, and only the simple mechanism is used, it is inexpensive. It can be realized, and unnecessary load does not occur during FWD traveling. Further, since the swing gear 14 and the brake switching lever 43 are separated from each other during unloading, there is no obstacle when performing an operation different from that during FWD / RVS traveling. Furthermore, since the back tension torque during RVS traveling can be set independently of the winding torque during FWD traveling, the degree of freedom in design can be increased.

According to the above-mentioned embodiment, the reflection type photo coupler is used as the means for detecting the rotational position of the brake clutch, but other means such as a transmission type optical sensor may be used.

[0020]

As described above, according to the present invention, the movable chassis in which the supply reel base and the take-up reel base are rotatably attached to the fixed chassis in which the rotary head drum is rotatably attached is reciprocally movable. A reel of a VTR in which a swing gear that is disposed and swingably meshes with one of the supply reel base and the take-up reel base to drive the one reel base is swingably supported on the fixed chassis. In the table brake device, a brake switching lever is rotatably supported by the movable chassis, and the brake switching lever and the swing gear that moves close to and away from the brake switching lever are positioned relative to one of the reel tables. Since it is configured to turn on / off the brake, it is possible to simplify the structure of the reel stand brake device and reduce the cost. And, it is possible to prevent the occurrence of unnecessary load upon FWD running.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a VTR showing an embodiment of the present invention.

FIG. 2 is a schematic plan perspective view of the movable chassis of the VTR before sliding.

FIG. 3 is a schematic plan perspective view after completion of sliding of the movable chassis of the VTR.

FIG. 4 is a partial side view showing, in cross section, a part of a main part after completion of sliding of the movable chassis of the VTR.

FIG. 5 is a cross-sectional view of a main part after completion of sliding of the movable chassis of the VTR.

FIG. 6 is an explanatory diagram of a reel stand brake device during unloading of the VTR.

FIG. 7 is an explanatory diagram of a reel stand brake device during loading of a tape guide after completion of sliding of a movable chassis of the VTR.

FIG. 8 is an explanatory view of the reel stand brake device at the time of stop after the loading of the VTR is completed.

FIG. 9 is an explanatory diagram of a reel stand brake device during FWD traveling of the VTR.

FIG. 10 is an explanatory diagram of a reel stand brake device during RVS traveling of the VTR.

FIG. 11 is a cross-sectional view of a conventional VTR reel stand brake device.

FIG. 12 is a cross-sectional view of another conventional VTR reel stand brake device.

[Explanation of symbols]

 1 ... VTR 3 ... Rotary head drum 10 ... Fixed chassis 14 ... Swinging gear 16 ... Cam 20 ... Movable chassis 23 ... Supply reel stand 24 ... Winding reel stand 28 ... Gear 40 ... Reel stand braking device 41 ... Brake claw 42 ... Brake release lever 43 ... Brake switching lever 50 ... Brake clutch 56 ... Gear

Claims (4)

[Claims] 1. A movable chassis having a supply reel base and a take-up reel base rotatably mounted on a fixed chassis having a rotary head drum rotatably mounted thereon, the movable chassis being reciprocally movable.
A VTR swingably supported on the fixed chassis by a swing gear that swings and meshes with one of the supply reel base and the take-up reel base to drive the one reel base.
In the reel stand brake device of any one of the above, either one of the reels is rotatably supported by the movable chassis and the positional relationship between the brake switch lever and the swing gear that moves close to or away from the brake switch lever. A reel stand brake device for a VTR, which is configured to turn on / off a brake for the stand. 2. The VTR reel base brake device according to claim 1, wherein when the swing gear meshes with the supply reel base, the take-up reel base is braked by a brake switching lever. VTR reel stand brake device. 3. The VTR reel base brake device according to claim 1, wherein the brake clutch meshes with a gear of the take-up reel base, and the gear of the brake clutch is arranged so as to mesh with and separate from the gear of the brake clutch. A VTR is provided with a brake pawl that sometimes applies a brake to the take-up reel base via a brake clutch, and a brake switching lever that switches the brake pawl so as to engage with and disengage from the gear of the brake clutch. Reel stand brake device. 4. The reel stand brake device for a VTR according to claim 3, further comprising a brake release lever that is interlocked by a cam rotatably supported on the fixed chassis side, and the brake release lever allows the brake pawl to move. A reel base brake device for a VTR, which is configured to release a meshing state of a brake clutch with a gear.