JPH02236849A - Reel base control mechanism - Google Patents

Abstract

PURPOSE:To prevent the beating noise of a ratchet, and to decrease an operating noise by providing an engaging part which dislocates a releasing lever in the direction to eject the interference with the ratchet by means of the turn of a lock control lever on the lever. CONSTITUTION:A ratchet 12 is rotated in the direction of an arrow D in a STOP mode, and a blade 12a pressures the releasing lever 9 in the direction of an arrow E. As a result, a locking lever 8 turns in the direction of an arrow C around a supporting shaft 7, releases the locking between a level difference part 8a and a first pin 5, a cam lever 1 turns in the direction of an arrow A, and the reel base is braked. Simultaneously, a cam gear 3 turns in the direction of an arrow F, a locking control lever 13 is guided through a second pin 15 to a second cam groove 16, it turns in the direction of an arrow G around a supporting shaft 14, an engaging part 13a enters the underside of a flange part 9a at the tip of the canceling lever 9, upward pushes the canceling lever 9, and ejects the interference with the blade 12a of the ratchet 12.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a video tape recorder (hereinafter referred to as VTR).
The present invention relates to a reel stand braking mechanism for stopping the rotation of a reel stand provided in a magnetic recording/reproducing device such as the above.

(Prior art) These reel stands installed in VTRs, etc. are used for fast forwarding (
A brake mechanism is provided for instantaneously stopping a high-speed rotating state such as a FF or REW state. This reel stand brake mechanism has conventionally been constructed as shown in FIG. In the figure, a cam lever 1 that drives a reel stand brake (not shown) is rotatably supported via a support shaft 2 with respect to a base plate.

Further, a cam gear 3 that is rotatably driven by a drive source (not shown) is provided on the substrate, and a first cam groove 4 formed in the cam gear 3 has a first cam groove 4 formed at one end of the force lever 1. The lower end of the pin 5 is slidably engaged. The force lever 1 is urged to rotate in the eight directions of arrows by an unillustrated urging means, and the rotation of the cam gear 3 causes the cam lever 1 to brake or release the reel stand.

On the other hand, a lock lever 8 whose one end is rotatably attached to the bracket 6 via a support shaft 7 is provided on the upper surface of the bracket 6 provided parallel to the board and above the cam gear 3. A stepped portion 8a is formed on one side of the date lever 8, with which the upper end of the first pin 5 provided on the force lever 1 can be engaged. When the pin 5 comes into contact with this stepped portion 8a, the rotation of the cam lever 1 in the eight directions of the arrow is stopped, so that the brake release state can be maintained. Then, the first pin 5 engages with the stepped portion 8a of the lock lever 8, and when the brake is released, the lower end of the first pin 5 engages with the first cam groove 4. The width is increased so that when the engagement between the first pin 5 and the stepped portion 8a is released, the cam lever 1 rotates in the eight direction of the arrow and instantly brakes the reel stand. There is. Further, a mountain portion 4 is provided at one end of the wide portion 4a of the first cam groove 4.
When the first pin 5 reciprocates on both sides of this peak 4b, the cam lever 1 is rotated and locked in conjunction with the rotation of a lock lever 8, which will be described later.

One end of a release lever 9 is rotatably attached to one end of the lock lever 8 via a support shaft 10, and the release lever 9 is biased in the direction of arrow B by a spring 11. A flange 9a is provided at the other end of the release lever 9, and a blade 12a of a ratchet 12 which is rotatably driven by a drive source (not shown) can come into contact with this flange 9a. Then, due to the rotation of the ratchet 12, the blade 12a
presses the flange 9a of the release lever 9 against the biasing force of the spring 11, rotates the lock lever 8 in the direction of arrow C, and releases the step 8a of the lock lever 8 and the first pin 5 of the cam lever 1. The rotation of the reel stand is instantly braked by disengaging the reel. In addition, the bracket 6 and force gear 3
There is a roughly triangular lock control lever 1 between the
3 is provided, and this lock control lever 1
3 is rotatably attached to the bracket 6 via a support shaft 14. A second pin 15 implanted in this lock control lever 13 is slidably engaged with a second cam groove 16 formed in the cam gear 3. The third pin 17 projects into a window 8b formed in the lock lever 8.

In the conventional reel stand braking mechanism configured as described above, in the FF and REW states shown in FIG. The brake has been released. FF, REW
When it stops, the ratchet 12 starts rotating in the direction of arrow D, the blade 12a slides the release lever 9 in the direction of arrow E against the urging force of spring 11, and the lock lever 8 is rotated in the direction of arrow C. Move. As a result, the engagement between the first pin 5 of the cam repercussion 1 and the stepped portion 8a of the lock lever 8 is released, and the cam repercussion 1, which is urged to rotate in the eight directions of the arrows, rotates in the same direction, and the reel stand is rotated. It brakes instantly. After the lock is released, cam gear 3 rotates in the direction of arrow F, and cam gear 1
is guided by the first cam groove 4 via the first pin 5, rotates, and reaches the stop position. At the same time, the lock control lever 14 rotates while being guided by the second cam groove 16 via the second pin 15, and the third pin 17 pushes the window 8b of the lock lever 8, causing the lock lever 8 to move toward the point indicated by the arrow C. direction to retract the release lever 9 from the ratchet 12. Also, when entering FF, REW mode again, cam gear 3
is rotated in the opposite direction, and the state shown in FIG. 4 is obtained by performing the operation opposite to that described above.

In the above operation, when the cam gear 3 rotates in the direction of arrow F after the cam reper 1 is unlocked, and the first pin 5 of the cam reper 1 rides on the peak 4b of the first cam groove 4. At this time, the lock lever 8 is no longer locked by the first pin 5, so the lock lever 8 is free to rotate. Therefore, the tip of the release lever 9 comes into contact with the blade 12a of the rotating ratchet 12 and is struck, causing discomfort while the first pin 5 climbs and descends the peak 4b of the first cam groove 4. Generates a rattling sound.

(Problems to be Solved by the Invention) As described above, according to the conventional reel stand braking mechanism, after the lock lever unlocks the cam lever, the lock lever is temporarily free to rotate, and the lever that drives the release lever is There was a problem in that the check and the tip of the release lever interfered, resulting in an unpleasant tapping sound.

The present invention has been made in view of these points, and it is an object of the present invention to provide a reel stand braking mechanism that can reduce operational noise when transitioning from fast forward or rewind mode to stop mode.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention provides a cam lever that drives a reel stand braking brake, a cam gear that drives this cam lever, and locking and unlocking of the cam lever. A lock lever is connected to this lock lever,
A reel stand system comprising a release lever that drives the lock lever, a ratchet that presses the release lever in the unlocking direction, and a lock control lever that is driven by the rotation of the cam gear and adjusts the position of the lock lever. In the lock control lever, the lock control lever is provided with an engaging portion that, when rotated, displaces the release lever in a direction that eliminates interference with the ratchet.

(Function) According to the above configuration, STOP from FF, REW mode
When entering the mode, the release lever is pressed by the rotation of the ratchet, the lock lever connected to this release lever rotates, the cam lever that was locked by the lock lever is unlocked, and the cam lever instantly releases the reel. The platform is braked. At this time, the lock control lever is rotated by the cam gear, and the engaging portion provided at the tip of the lock control lever is inserted into the lower surface of the release lever to push the release lever upward and eliminate interference with the ratchet. As a result, the tapping sound of the ratchet hitting the release lever is eliminated, and the operation noise becomes quieter.

(Embodiment) Hereinafter, an embodiment of the reel stand braking structure according to the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, parts that are the same or equivalent to those of the conventional example shown in FIG. 4 are denoted by the same reference numerals, and explanations thereof will be omitted. The feature of this embodiment is that the lock control lever 13 has an engaging portion 13a@Kl at the tip thereof, and when the lock control lever 13 rotates due to the rotation of the cam gear 3, the engaging portion 13a is attached to the lower surface of the tip of the release lever 9. The structure of the other parts is the same as the conventional example shown in FIG. 4, except that the release lever 9 is lifted to eliminate interference with the blades 12a of the ratchet 12.

Further, a tapered surface 9b is formed on the lower surface of the flange portion 9a at the tip of the release lever 9 on the side where the engaging portion 13a is inserted in order to facilitate insertion of the engaging portion 13a. Incidentally, reference numeral 18 in the figure is a support shaft provided at the center of the cam gear 3.

Next, the operation of this embodiment will be explained with reference to FIGS. 1 to 3. 1, 2(a) and 3(a) show the states in the FF and REW modes, respectively. The brake of the reel stand is released by the cam lever 1. In this state, the rotation of the ratchet 12 is stopped. FF, REW mode is S
When in TOP mode, the ratchet 12 instantly moves to arrow D.
The blade 12a of the ratchet 12 presses the release lever 9 in the direction of arrow E. As a result, the lock lever 8 rotates in the direction of arrow C about the support shaft 7, and the step portion 8a formed on the lock lever 8 is disengaged from the first pin 5, and the cam lever 1 is rotated (not shown). The reel stand is rotated in the eight directions indicated by the arrow by the biasing means, and the reel stand is instantly braked. At the same time, the cam gear 3 rotates in the direction of arrow F, and the lock control lever 13 is guided by the second cam groove 16 via the second pin 15 and rotates in the direction of arrow G about the support shaft 14. Then, as shown in FIG. 2(b) and FIG. 3(b), the engagement portion 13a at the tip of the lock control lever 13 enters the lower surface of the flange portion 9a at the tip of the release lever 9, and the release lever 9 Push up and remove blade 12 of ratchet 12.
Eliminate interference with a. When the cam gear roughly rotates in the direction of arrow G, the lock control lever 13 further rotates in the direction of arrow G.
A third pin 17 attached to the lock lever 8 contacts the peripheral edge of a window 8b formed in the lock lever 8, and rotates the lock lever 8 about the support shaft 7 in the direction of arrow C. As a result, as shown in FIGS. 2(C) and 3(C), the tip of the release lever 9 is separated from the ratchet 12 in the horizontal direction, and the blade 12a of the rotating ratchet 12 does not hit the release lever 9. do not have. Other operations are similar to the conventional example.

According to this embodiment, since the ratchet 12 does not interfere with the release lever 9 when transitioning from the FF/REW mode to the STOP mode, no unpleasant tapping sound is generated and the operating noise of the VTR is reduced. be able to.

[Effects of the Invention] As explained above, according to the present invention, when the magnetic recording/reproducing device shifts from the fast forward or rewind mode to the stop mode, the release lever for braking the reel stand and the ratchet interfere with each other. Therefore, it is possible to prevent unpleasant tapping noise from occurring and reduce operating noise.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a perspective view showing an embodiment of the reel stand braking mechanism according to the present invention, FIGS. 2 and 3 are a plan view and a side view, respectively, showing the operation of this embodiment. FIG. 4 is a perspective view showing a conventional reel stand braking mechanism. 1...Cam lever 3...Cam gear 8...Lock lever 9...Release lever 12...Ratchet 13...Lock control lever 13a...Representative of the engaging part Patent attorney Noriyuki Chika Yudo Hiroshi UjiFigure 1Figure 3

Claims (1)

[Claims] A cam lever that drives the reel stand braking brake, a cam gear that drives this cam lever, a lock lever that locks and unlocks the cam lever, a release lever that is connected to this lock lever and that drives this lock lever, and this release lever. A reel stand braking mechanism comprising a ratchet that presses in a lock release direction and a lock control lever that is driven by the rotation of the cam gear and adjusts the position of the lock lever, A reel stand braking mechanism, further comprising an engaging portion that displaces the release lever in a direction to eliminate interference with the ratchet.