JPH03187047A - Driving mechanism for magnetic recording and reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive mechanism in a magnetic recording/reproducing device such as a VTR, and particularly to a drive mechanism using a cam gear.

[Conventional technology] Conventionally, as a drive mechanism in a nuclide VTR.

The rotation of the motor is transmitted to the gear (hereinafter referred to as the cam gear) that is the center of mechanism operation via an appropriate speed reduction mechanism, and is engaged with the cam grooves provided on the front and back surfaces of the cam gear and the cam surface formed on the outer peripheral surface. A device is known in which a plurality of arms or the like are given a predetermined rotational displacement or sliding displacement according to the rotation angle of a cam gear to perform a predetermined operation. A VTR drive mechanism using such a cam gear is disclosed in, for example, Japanese Patent Laid-Open Nos. 56-114154 and 1982-1478.
It is disclosed in Publication No. 45 and the like.

In recent years, as VTRs have become more multi-functional and smaller, there have been increasing restrictions on the arrangement of the cam gear and the members controlled by the cam gear, even in the above-mentioned cam gear drive mechanism. FIGS. 6 and 7 are diagrams showing an example of a brake mechanism for a capstan wheel using a conventional cam gear drive mechanism.

FIG. 6 is a plan view of the brake mechanism in a brake released state. In the figure, the brake 3, which is rotatably attached to a support shaft 5 implanted in the chassis 25, is biased in the direction of arrow C by a spring 7. By abutting the joint portion 6 with the operation surface 11 of the operation member 8, it is held at a predetermined release position with respect to the wheel brake surface 1a of the wheel 1, which is provided to be rotatable integrally with the capstan shaft 2. Here, shafts 17 and 18 implanted in the chassis 25 are engaged with the length 9.10 of the operating member 8, and the operating member 8 is
It can be slid in any direction. And the operation member 8
The arrow f is caused by the contact between the engaging portion 6 and the operating surface 11 described above.
At the same time, the cam contact portion 12 is held in a predetermined position by contacting the cam surface 15c of the cam gear 13 rotatably provided on the support shaft 14 implanted in the chassis 25. There is. The cam gear 13 is provided with a gear portion 16 below the cam 15, and the rotational force from a motor (not shown) is transmitted to the gear portion 16 via an appropriate speed reduction mechanism.
As a result, the cam gear 13 is driven to rotate in both forward and reverse directions.

Now, when the cam gear 13 is rotated by a predetermined angle in the direction of arrow a from the state shown in FIG.
As shown in the figure, the cam contact portion 12 of the operating member 8 is connected to the cam recess 21.
Since the operating member 8 is located within the engaging portion 6 of the brake 3
The brake pad 3 is pressed by and slides in the direction of arrow f, and in conjunction with this, the brake 3 rotates in the direction of arrow C until the brake pad 4 comes into contact with the wheel brake surface 1a. Also,
When the cam gear 13 is rotationally driven in the direction of the arrow a from the state shown in the seventh figure, the cam surface 15b is rotated, and conversely, when the cam gear 13 is rotationally driven in the direction indicated by the arrow from the state shown in the seventh figure, the cam surface 15a is
presses the cam contact portions 12 of the operating member 8, respectively,
The cam contact portion 12 moves the operating member 8 in the direction of the arrow e so that the cam surface 1
5c, the brake 3 is rotated in the direction of arrow g, and the brake 3 and operating member 8 are returned to the state shown in FIG. 6. Therefore, the wheel 1 receives a predetermined braking force only when the cam gear 13 has a predetermined rotation angle, that is, when the cam contact portion 12 of the operating member 8 is positioned within the cam recess 21 of the cam gear i3.

[Problems to be Solved by the Invention] By the way, due to the demand for space saving accompanying the multifunctionality and miniaturization of VTRs, the shaft 20 installed in the chassis 25 is
The arm 19, which engages with a cam groove (not shown) provided on the back surface of the cam gear 13 and is driven in the direction of arrow d in FIG. 7 as the cam gear 13 rotates, is operated with the chassis 25 with If the shaft 18 is to be provided between the arm 19 and the arm 19, the shaft 18 that engages with the long lO of the operating member 8 and slidably guides the operating member 8 interferes with the arm 19, and the shaft 18 is provided as shown in FIGS. becomes impossible.

As a countermeasure for this, as shown in FIG.
It is conceivable to provide the elongated hole IO in a position where it does not interfere with the arm 19, but in this case, the space occupied by the operating member 8 will be significantly increased, and this will help to save space due to miniaturization and multifunctionalization. Furthermore, assembly for automatic assembly by robots is disadvantageous in terms of space.

On the other hand, as shown in FIG. 9, the operating member 8 is provided with a guide surface 8a parallel to the sliding direction and a guide shaft 22, 23 that slides in contact with the guide shaft 22, 23 at a position where the arm 19 does not interfere with the guide surface 8a, thereby controlling the rotation of the operating member 8. There is also a method of regulating the sliding movement, but this increases the number of guide members, which increases costs, and requires securing space for a plurality of guide members, which poses a problem in terms of space saving.

An object of the present invention is to provide a drive mechanism that does not cause an increase in cost and arrangement space when drive mechanism components are subject to restrictions in arrangement as described above.

[Means for Solving the Problems] In order to achieve the above object, the cam gear drive mechanism of the present invention includes a controlled member that is linked to an operating member that moves differently along the cam surface depending on the rotational direction of the cam gear. are configured to be controlled in substantially the same way for a predetermined rotation angle of the cam gear, regardless of the rotation direction of the cam gear.

[Function] When the cam gear rotates in one direction, the operating member moves along the cam surface of the cam gear and is restricted from rotating, and only slides to control the linked controlled member, and the cam gear rotates in the other direction. When rotating, the operating member rotates and slides along the cam surface of the cam gear,
Controls controlled members that operate in conjunction. Here, so that the operation of the controlled member is drive-controlled in substantially the same way for a predetermined rotation angle of the cam gear, regardless of the rotation direction of the cam gear,
The interlocking relationship between the controlled member and the operating member is set appropriately. Therefore, while allowing rotation of the operating member, it is possible to control the controlled member (brake) in the same way as in the case where the conventional operating member performs only a sliding action. As described above, the present invention allows the operating member to slide and rotate at the same time in a certain direction of rotation of the cam gear.
Since the restriction on the movement of the operating member, which was conventionally limited to sliding movement, is relaxed, this is advantageous against restrictions on component arrangement in a drive mechanism using a cam gear.

[Example] The present invention will be explained below with reference to an example shown in FIGS. 1 to 5.

FIG. 1 is a plan view of a main part of the brake mechanism in a braking state driven by a cam gear of a VTR.

In contrast to the conventional examples shown in FIGS. 6 and 7 described above, in this embodiment, as shown in FIG. is engaged in. In the state shown in FIG. 1, when the operating member 9 rotates in the direction of the arrow j, the guide surface 8a formed on the operating member 8 in parallel with the longitudinal direction of the elongated hole 9 moves toward the chassis 25.
It is regulated by coming into contact with a regulating shaft 22 installed in the. The operating member 8 also has a brake engagement hole 2.
4, and a cylindrical engaging portion 6 of the brake 3 is engaged with the brake engaging hole 24 from below so as to be relatively displaceable by a predetermined amount. Here, the engaging portion 6 is not restrained by engagement with the brake engaging hole 24, and therefore, the brake 3 presses the brake pad 4 against the wheel braking surface 1a by the biasing force of the spring 7, and presses the brake pad 4 against the wheel braking surface 1a. is in a braking state.

When the cam gear 13 is rotationally driven in the direction of arrow a from the state shown in FIG. 22 and is slid in the direction of arrow e. At this time, the engaging portion 6 of the brake 3 is pressed against the engaging surface 24a of the brake engaging hole 24 provided in the operating member 8, and the brake 3 is moved to the cam contact portion of the operating member 8, as shown in FIG. The brake 3 rotates in the direction of arrow g until the brake 12 rides on the cam surface 15c, and the brake 3
The state shifts to the state shown in FIG. 4 in which the braking applied to the wheel l is released. At this time, the operating member 8 is also urged in the direction of the guide surface 8a coming into contact with the regulation shaft 22 (in the direction of arrow j) due to the reaction force of the engaging surface 24a pressing the engaging portion 6,
Therefore, as shown in FIG.
After riding on the operating member 8, the operating member 8 is held at a position where the guide surface 8a is in contact with the regulating shaft 22, regardless of the rotational direction of the cam gear 13.

On the other hand, when the cam gear 13 is rotationally driven in the direction indicated by the arrow from the state shown in FIG. 1, the cam contact portion 12 is pressed against the cam surface 15a, as shown in FIG. The operating member 8 rotates in the direction indicated by the arrow until the engaging surface 24b of the brake engaging hole 24 comes into contact with the engaging portion 6 of the brake 3. The operation member 8 is brought into contact with the engaging portion 6 and the engaging surface 24b.
Since the rotation in the direction of the arrow is restricted, next see Figure 3 (b).
), the operating member 8 slides in the direction of arrow i until the engaging surface 24a of the brake engaging hole 24 and the engaging portion 6 of the brake 3 come into contact. Note that the engaging surface 24a is formed obliquely to the longitudinal direction of the elongated hole 9 at a predetermined angle, and the engaging surface 24b is formed parallel to the longitudinal direction of the elongated hole 9. The third above
From the state shown in Figure (b), the cam contact portion 1 of the operating member 8 is
2 is pressed by the cam surface 15a, the engaging portion 6 of the brake member 3 is pressed by arbitrary rotation and sliding movements of the operating member 8, whereby the brake member 3 is pressed by the cam surface 15a.
At a predetermined rotation angle of the cam gear 13 shown in FIG. 2, the brake is released.

Further, at the above-described predetermined rotation angle of the cam gear 13,
FIG. 5 shows a case where the cam gear 13 is rotating in the direction of arrow a. In FIG. 5, the cam contact portion 12 of the operating member 8 is in contact with the boundary between the cam surface 15c and the cam surface 15a, and when the cam gear 13 is further rotationally driven in the direction of arrow a from this state, the operating member 8 moves in the direction of the arrow along the cam surface 15a, and accordingly the brake 3 starts rotating in the direction of the arrow C to brake the wheel l.

Here, the predetermined rotation angle explained with reference to FIGS. 2 and 5 means the rotation angle at which the brake 3 is reliably released by the cam surface 15c.

That is, FIG. 2 shows that even when the cam gear 13 is rotationally driven in the direction of the arrow and the operating member 8 rotates and slides, the brake is reliably released at a predetermined rotation angle, and the amount of release is also the same as that shown in FIG. This shows that there is no problem in terms of performance. Note that when the cam gear 13 further rotates in the direction indicated by the arrow from the state shown in FIG.
Since the cam abutting portion 12 performs arbitrary rotation and sliding operations until it rides on the cam surface 15c, the brake 3 is further driven in the direction of arrow g, but in any case, in the direction in which the brake is released. In addition, after the cam contact portion 12 rides on the cam surface 15c, the engaging surface 24a or 24b of the brake engaging hole 24 of the operating member 8 will contact the engaging portion 6 of the brake 3. Due to the reaction force pressing the operating member 8, the operating member 8 is held at the position where the guide surface 8a and the regulating shaft 22 are in contact with each other, as in FIG. 4.5.

As described above, in this embodiment, even when the brake 3 is controlled by the cam surface 15a of the cam gear 13, where the brake 3 is not controlled only by the sliding operation of the operating member 8, the same brake control operation as the conventional one can be obtained. and,
By doing so, the operating member 8 only needs to have two guide shafts, the same as the conventional example shown in Fig. 6.7, so there is no increase in cost, and one guide shaft can be connected to the arm described above. It becomes possible to arrange the device outside the movement locus of No. 19. Moreover, since the brake engagement hole 24 is simply provided in the operating member 8, the space occupied by the operating member 8 does not increase significantly.

[Effects of the Invention] As described above, according to the present invention, since the rotation and sliding motion of the operating member operated by the cam gear can be simultaneously permitted, there are no restrictions on the arrangement of the drive mechanism components in the drive mechanism using the cam gear. Even in the case of a large amount, an inexpensive and space-saving mechanism can be realized, contributing to the miniaturization and multifunctionality of the device. Furthermore, since the operating member can engage the pin slot at one location with the guide member, assembly is easy and automatic assembly by a robot is also facilitated.

[Brief explanation of drawings]

1 to 5 relate to a brake mechanism using a cam gear of a VTR according to an embodiment of the present invention, FIG. 1 is a plan view of the main part in a braking state, and FIG. 2 is a counterclockwise rotation of the cam gear. A plan view of the main part showing the state at a predetermined rotation angle at the time,
Figures 3(a) and (b) are plan views of main parts showing the brake release operation when the cam gear rotates counterclockwise, and Figure 4 shows the state immediately after the brake is released when the cam gear rotates clockwise. 5 is a plan view of the main part showing the state of the cam gear at a predetermined rotation angle when rotating clockwise; FIGS. 6 and 7 relate to the first conventional example; and FIG. 6 shows the brake. FIG. 7 is a plan view of the main parts showing the brake mechanism in the released state; FIG. 7 is a plan view of the main parts showing the brake mechanism in the braking state; FIG. 8 is a plan view of the main parts showing the second conventional brake mechanism; The figure is a plan view of main parts showing a third conventional brake mechanism. l...Wheel, 1a...Wheel brake surface, 2...Capstan transport, 3...
...Brake, 4...Brake pad, 5...
...Support shaft, 6...Engagement part, 7...
Spring, 8... operation member, 8a guide surface,
9...Elongated hole, 12...Cam contact part, 1
3...Cam gear% 15, 15a, 15b, 1
5c---Cam surface, 16...Gear part, 17...
...Shaft, 19...Arm, 21...
...Cam recess, 22...Regulation shaft, 2
4... Brake engagement hole, 24a, 24b...
...Engagement surface. 5 1; Wheel 3 Brake 6: Engaging part 7: Sublisig 8: Akizumi chopsticks material 80 Ni guide surface 9: Long end 12: Cam contact part I3
:Cam 〒°ya 15a, 15b, 15c: Power 4! o
19: Arm 21: y7 recess 22 1", Yat 24: Play key distortion 4 to light 240
, 24b: Section 4> Page 311 (a) (b) 41st! No. 511 Ditch 6 Figure 16 No. 9 Meat

Claims (1)

[Claims] 1. A cam gear to which the rotational force of the motor is transmitted via an appropriate reduction mechanism, an operating member that is rotatable and slidable and driven to follow the cam surface of the cam gear, and a rotation range of the operating member. a regulating member that limits the cam surface, a biasing means that biases the operating member in a direction in which it comes into contact with the cam surface and the regulating member, and a controlled member that is controlled in conjunction with the operating member; A first operating mode in which the member is slidably driven by the cam surface while sliding on the regulating member, and a second operating mode in which the operating member is arbitrarily rotated and slidably driven by the cam surface. . A drive mechanism for a magnetic recording and reproducing apparatus, characterized in that the controlled member that is linked to both the first and second operation modes operates in substantially the same way in both operation modes.