JPS58147845A - Magnetic tape device - Google Patents

Abstract

PURPOSE:To eliminate the need for a fine adjustment when a position detecting switch for operation mode is fitted, by allowing the position relation between a fixed and a movable contact to be set and detecting electrically the position of operation mode. CONSTITUTION:Once a playback button is pressed, a main cam 162 rotates by 40 degrees to start lead out of a magnetic tape and finishes the leading-out operation at a 180-degree angle of rotation. When cams 162 and 142 further rotate, the movable contact part 53 of the detecting switch 43 rotates continuously through the rotation of the cam 142 to bring into contact with a brush 63 and the fixed contact 65d at a 205-degree angle of rotation, and fixed terminals 69a and 69b are connected electrically to stop the motor, thereby stopping the rotation of the cams 142 and 162. At this time, a tape is wound without any sag and a playback mode is set. When a stop button is pressed, the motor reverses to allow the cams 142 and 162 to start rotating, and at a 0-degree angle of rotation, the brush 63 and fixed contact 65c of the detecting switch 43 come into contact with each other to make an electric connection between the fixed terminals 69a and 69b; then the motor stops and the cams 142 and 162 stops to set a stop mode.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects a moving member that moves to a plurality of positions in response to various operation modes such as stop, playback, and fast forwarding, and detects the position of the moving member, The present invention relates to a magnetic tape device such as a video tape recorder having a detection means for detecting whether or not the magnetic tape is present.

In recent years, a method for switching the operating mode of a magnetic tape device has been developed as a low-cost, lightweight device that uses a motor to rotate a cam without using a solenoid, and a moving member that follows the cam and moves to multiple positions. (Special request 1977)
5-15263).

Then, the displacement of the moving member is determined by, for example, Japanese Patent Application No. 66-30.
As shown in No. 405, the type of operation mode is detected by detecting the conduction state between a movable terminal that is integrally displaced with the movable member and a fixed terminal corresponding to each operation mode. However, this method was published in the patent application No. 56-19390
As pointed out in No. 4, since the movement of the moving member moving along the slope of the cam is directly detected, the moving member does not stop on the slope during movement, and temperature changes and changes over time There was a problem in that the stopping position varied greatly due to load fluctuations due to factors such as the following.

Furthermore, as shown in Japanese Patent Application No. 55-11754, in this conventional system, a first display part is provided on a movable part having a movable terminal that moves integrally with the movable member, and the display part is arranged in a predetermined positional relationship. providing a second display section corresponding to the first display section;
The present invention solves the above-mentioned problems, which were one of the factors that hindered the rationalization of production of the device, such as requiring delicate adjustment to match the first display section and the second display section. The present invention aims to provide a magnetic tape device that can be easily assembled automatically. below,
The present invention will be explained in detail based on illustrated embodiments.

1 and 3 show top views of this embodiment. In the figure, a take-up reel stand 10 and a supply reel stand 12, which are rotatably loosely fitted to shafts 4 and 6 installed on the upper surface of the substrate 2, are cassettes.
When the cassette 20 is attached to the specified location on the main body of the device, the cassette) 2
They are engaged with the take-up reel hub 14 and the supply reel hub 16 in the reel base 10, respectively, and can rotate together with the claws 8 provided on both the reel stands 10 and 12. FIG. 2 shows a sectional view of the reel stand drive system. The supply reel stands 12 each have a reel gear 30,40, the reel gear 30,
40 is engaged with a take-up reel idler gear unit 62 and a supply reel idler gear unit 62, which are rotatably loosely fitted onto a shaft 60°6o set up on the substrate 2, and are driven to rotate. The take-up reel idler gear unit 52 and the supply reel idler gear unit 62, as shown in FIG. The structure is such that the power is transmitted to the take-up reel idler gear 64b, which meshes with the reel gear 30.40, and the supply reel idler gear 64b, via the clutch means.

On the other hand, a capstan 72 rotatably supported by a bearing member 70 fixed to the substrate 2 has a rotating roller portion 74 in a part thereof,
A predetermined pressing force is applied to the rotating roller portion 74, and the rotation is transmitted to the main idler 76, which is pressed against the rotating roller portion 74. The main idler 76 includes a pulley portion 78 that is integrally constructed, and a relay row 2 that is rotatably loosely fitted to a shaft 8o that is set on the base plate 2.
A belt 84 is stretched between the belt 82 and the belt 82, and its rotation is transmitted to the relay row 282. A rotating arm 88 with a rotatable idler gear 86 supported at one end is loosely fitted to the shaft 8o, and a multi-pole magnetized magnet 90 is arranged around the outer periphery so as to be approximately concentric with the shaft 8o. , are placed in one piece.

Furthermore, a magnet 90 is provided on the inner periphery of the relay roller 82.
A magnetic material 92 having a magnetic hysteresis characteristic is fixed to face the relay row 2 with a predetermined clearance, and generates a predetermined attractive force between the magnet 90 and the relay row 2.
A rotational force in the same direction as the rotational direction of the rotation arm 82 is applied to the rotation arm 88. Further, the idler gear 86 is configured to always mesh with a gear portion 94 provided on the relay row 282, and depending on the operation mode of the device, the take-up reel idler gear s4a is rotated by the rotation of the relay roller 82.
Alternatively, it is configured to mesh with either the supply reel idler gear 64a and selectively transmit the rotation of the capstan 72 to the take-up reel stand 10 or the supply reel stand 12 depending on the direction of rotation.

A pinch roller lever 22 is rotatably fitted loosely into a shaft 18 planted on the substrate 2, and a pinch roller 192 is rotatably supported on a shaft 24 mounted on one end of the pinch roller lever 22. has been done. A crimping lever 32 having an elongated size 28 is loosely fitted onto a shaft 2e that is rotatable and slidable in the longitudinal direction, and a pin 34 that is installed at one end of the lever 32 is rotatable. A connecting arm 36 is loosely fitted to the pin 38, and the other end of the connecting arm 36 is rotatably fitted to a pin 38 set up on the other end of the pinch roller lever 22. A spring part 42 is formed at the other end of the crimp lever 32, and a tension spring 44 is stretched between the shaft 26 and the spring hook part 42, so that the crimp lever 32 In Figure 1, the shaft 26 is biased upward, and the end of the elongated hole 28 and the shaft 26 are in contact with each other. That is, the pinch roller lever 22, the connecting arm 36, and the pressure lever 32,
This constitutes a so-called toggle mechanism. Also,
At the other end of the crimp lever 32, a pin 46 is configured to pass through a hole (not shown) provided in the substrate 2, extend toward the rear surface of the device, and come into contact with a bent portion 21 provided in a main rod 48, which will be described later. .

Therefore, when the main rod 48, which will be described later in FIG. The pinch row 2192 rotates until it comes into contact with the capstan 72. The pinch roller lever 22 is not rotated after that, but the crimp lever 32 continues to rotate clockwise, so that the crimp lever 32 is guided into the elongated hole 28 against the biasing force of the tension P spring 44. 3, the pinch roller 192 is simultaneously pressed against the capstan 72 with a predetermined pressing force.

In the reproduction mode, as shown in Fig. 3, the supply reel hub 16
The magnetic tape 180 wound above is guided from the front side of the cassette 20 to a tape pull-out member 182 and 183 with guide posts 23, 25 and 27, 29, respectively, guided by guide grooves 31, 33, and fixed to the fixing member 184, It is pulled out until it moves to 185, and the rotating magnetic head 1
86 and a fixed head 188 for audio signal recording/playback.
and attached to a tape guide 190 fixed to the substrate 2. Furthermore, since the capstan 72 is rotating clockwise in FIG. 3, the main idler 76 is rotating counterclockwise in FIG. 3, and the belt 84 and relay row 282 are also rotating counterclockwise in FIG. do. Therefore, the rotating arm 88 is given a rotating force in the counterclockwise direction in FIG. 3 about the axis 8o,
The idler gear 86 rotating clockwise in FIG. 3 meshes with the take-up reel idler gear 54a, so the take-up reel stand 10 rotates clockwise via the clutch means described above, and the pinch roller 192 and capstan The magnetic tape 180 fed at a constant speed is wound around the take-up reel nozzle 14 without slack by the cooperation of the magnetic tape 72.

On the other hand, a driving gear 160 driven by a motor (not shown) is disposed on the back surface of the substrate 2 shown in FIG. It meshes with the fitted sub-cam 142. Further, the sub-cam 142 is rotatably loosely fitted onto a shaft 164 mounted on the base plate 2, and has a gear on its outer periphery having the same number of teeth as the outer peripheral gear of the sub-cam 142, and rotates in synchronization with the same angle as the sub-cam 142. The main cam 162 meshes with the main cam 162, which becomes a positive cam having a groove 166 extending over 360 degrees as shown in FIG. 10, and its lift curve has a lift amount as shown in FIG. The cam 7 lower 165, which will be described later, moves only in the changing section. Further, the rotating shaft 4 of the take-up reel stand 1o extending from the front surface to the back surface of the board 2, the rotating shaft 6o of the take-up idler gear unit 52, the guide shaft 132 planted on the back surface of the board 2, and the rotation of the main cam 162. The main cam 1 is attached to the moving shaft 164.
A main rod 48 having a cam follower 166 that engages with a groove 166 of 62 has guide grooves 35 , 37 , 39 provided in the main rod 48 .

41, it is loosely fitted so that it can be moved back and forth. Further, the main rod 48 is provided with the bent portion 21 so as to come into contact with a pin 46 provided at the other end of the crimp lever 32.

Further, the sub cam 142 is also shown in FIG.
The cam follower 1 is a positive cam having a groove 144 extending over e0, and its lift curve is as shown in FIG.
Sub-rod 1 having 46 and partially indicated by a dash-dotted line
30 is designed to reciprocate like the main rod 48.

Furthermore, as shown in FIGS. 4 and 6, a detection switch is provided on the back surface of the substrate 2, which is capable of meshing with the sub-cam 142 and detecting a predetermined rotation angle of the sub-cam 142.

The hole 43 is attached with a screw. The detection switch 43
The structure will be explained with reference to FIGS. 6 and 10.

46 is a rotating gear that meshes with the outer gear of the sub-cam 142, but the outer gear also has fewer teeth and therefore has a smaller diameter than the sub-cam 142, and the rotating gear 46 is integrally formed. It is rotatably supported by a shaft 49 in a case 47 . Also, the pinion 6 is attached to the shaft 49.
6 are integrally formed. A fixing member 61 is held and fixed to the case 47, and on one side of the fixing member 61, as shown in FIG. 9, six first fixed contacts 66a are provided on the outer periphery.

65b, 65C, 65d, 65e, and 65f, and a second fixed contact 67 is arranged on the inner periphery.

Reference numeral 63 denotes a movable contact portion which is rotatably loosely fitted onto the shaft 49 and has an internal gear 67 on its inner periphery. A transmission gear 6 rotatably and loosely fitted into a protrusion 69 provided on the case 47
1 meshes with the pinion 56 and the internal gear 67, and transmits the rotation of the pinion 55 to the movable contact portion 63 at a reduced speed. Further, the brush 63 is connected to the first fixed contacts 65a, 65b, 65c, 65d, 65e as shown by the dashed line in FIG.
.

The movable contact portion 6 is slidable by rotating the movable contact portion 63 on the esf and the second fixed contact 67.
3 is the installation. The brush 63 is the first fixed contact 65a, 65b, 65c.

When contacting any one of esd, 65e, and 65f, the pin 5'/63 and the first fixed contacts 65a, 65b.

There is electrical continuity between esc, esd, ese, and esf and between the brush 63 and the second fixed contact 67, and as a result, there is electrical continuity between the fixed terminals 69a and 69b.

Then, by detecting this electrical conduction state, the sub cam 1
42 and the rotation angle of the main cam 162 are detected.

In FIG. 10, the lift curve of the main cam 162 or the sub-cam 142 is at an angular position of -86° where the lift amount does not show any change.

-36°, 0°, 205°, 2500.3000 are angles corresponding to each operating mode of the device. It is not the gist of the present invention to explain everything about each operation mode here, so it will be omitted, but for example, as will be described later,
0 is the stopping mode and 205° corresponds to the reproducing mode. Then, the main cam 162 and the sub cam 142 are rotated at the rotation angles -85°, -35°, 0°, 2
06°.

When rotated to 250' and 3000 degrees, the first fixed contacts e 6a + e s b + e s c are located at the sliding positions of the brush 63 which slides and rotates accordingly.

I try to arrange esa, ass, and esf.

However, in this embodiment, the first fixed contact 66a.

Since independent terminals for esb, esc, esa, see, and esi are not provided and they are connected to a common fixed terminal e9a as shown in FIG. 9, the brush 63 is connected to any of the first fixed contacts 66. Fixed terminal 69 even if touched
A similar state of electrical continuity is simply obtained between a and 69b. Therefore, for example, when the main cam 162 and the sub cam 142 are rotated clockwise and counterclockwise in FIG. 4, respectively, with respect to the first fixed contact 65c corresponding to the stop mode as shown in FIG. When rotating in the positive direction, the first fixed terminal 69a, egb
If an electrical continuity state is obtained between them, it is determined that the rotation has been performed by a rotation angle of 205°, and secondly, if an electrical continuity state is obtained between the fixed terminals 69a and 69b, it is determined that the rotation has been performed by a rotation angle of 26o0. Electric circuit means (
It goes without saying that the following steps (not shown) are required.

Further, as shown in FIGS. 7 and 8, the detection switch 43 shown in this embodiment presses and biases the press bottle 71 toward the outer circumference of the movable contact portion 63 by the leaf spring 73, and A detent means is constituted by providing a groove 76 on the outer periphery so as to be able to engage and detach from the suppression bin 71. Then, the biasing force of the leaf spring 73 is set so that a predetermined rotational force is required to rotate the rotating gear 46 from the state in which the pressing pin 71 and the groove 75 are engaged with each other as shown in FIG. ing. Further, the fixed member 51 and the movable contact portion 53 are positioned such that when in this engaged state, the brush 63 is electrically connected to the fixed contact 65 cm corresponding to the rotation angle o0 of the main cam 162 and the sub cam 142. In addition to setting the relationship, the internal gear 67 is set so that the phase of the rotary gear 45 becomes a predetermined angle as described later.
, transmission gear 61. This is to set the locking phase of the pinion 56 and the rotary gear 46. Here, in order to further clarify the content of the present invention, the phase relationship when fixing the detection switch 43 to the chassis will be explained using FIGS. 5 and 6. When the sub-cam 142 is in the stopped state shown in FIGS. 4 and 6, the gear formed on the outer periphery of the sub-cam 142 is moved so that the bottom of the gear is located in the direction θ from the reference horizontal line shown in FIG. A first display portion 77 indicating the tooth bottom is provided near the outer peripheral gear of the sub-cam 142 in a phase relationship, and a hole approximately the same as the first hole 79 is provided in the sub-cam 142 so as to coincide with the first hole 79 provided in the substrate 2. A wide elongated hole 81 is provided. When installing this detection switch 43, the rotational position of the sub-cam 142 shown in FIG. 6 can be determined particularly reliably by passing a jig 83 shown by a dashed line in FIG. 6 through the first hole 79 and the elongated hole 81. Needless to say.

On the other hand, the detection switch 43 in which the suppressing pin 71 is engaged with the groove 75 of the movable contact portion 53 is provided in the detection switch 43, and the positioning portion asa and ssb are provided in a predetermined position of the board 2, a second hole 87a; The rotating gear 46 is fitted into the rotating gear 87b.
When meshing the sub cam 142 with the sub cam 142, the phase relationship is such that one tooth of the rotary gear 46 is located in the direction θ from the reference horizontal line shown in FIG. 46 near the outer periphery.

Therefore, when fixing the detection switch 43 to the board 2 in a stopped state, the sub cam 1 shown in the first display section 77 must be
The tooth bottom of the outer peripheral gear 42 and the tooth ridge of the rotary gear 45 shown in the second display section 89 are in mesh with each other as shown in FIG. Further, if the third hole 91 is provided in the substrate 2, the meshing state of the rotary gear 46 and the sub-cam 142 can be confirmed, which is convenient for practical use.

Further, since the content can be realized by well-known means, a detailed explanation will be omitted, but the tape pull-out members 182, 1
83 is configured to move according to the rotation of the main cam 162, and as shown in FIG. 10, the main cam 162 rotates from the stopped state of FIG.
The tape pull-out member 182 has a rotation angle range of up to 0°.
, 183 movement operations are performed.

Next, the operation of an embodiment of the present invention will be explained. 1st
When the regeneration button (not shown) is pressed from the stop state shown in FIG. 4 and FIG. and the main cam 162 are rotated counterclockwise and clockwise in FIG. 4, respectively. When the main cam 162 rotates to a rotation angle of 40 degrees, the tape pull-out members 182 and 183 begin to move, pulling the magnetic tape 180 into the cassette 2.
At the same time, the main rod 48 follows the groove 166 and begins to move rightward in FIG. 4, and the pinch roller lever 22 begins to rotate. Continued with cam 162
When the tape pull-out members 182 and 183 are rotated to a rotation angle of 18o0, the movement of the tape pull-out members 182 and 183 is completed, and the state shown in FIG. 3 is achieved. At this time, as shown in FIG. 10, the main rod 48 has moved approximately 411 meters to the right in FIG. 4, and the pinch roller 192 begins to contact the capstan 72. Further, as the cam 162 continues to rotate to a rotation angle of 2oo0, the main rod 48 moves six degrees to the right in FIG. 4, completing the predetermined pressure bonding of the pinch roller 192 to the capstan 72.

The main cam 162 and the sub cam 142 further rotate by 20 degrees.
Even when rotated from oO, the cam lift curve in FIG. 10 enters a horizontal portion.9 The main rod 48 and the sub-rod 130 do not move, but the movable contact portion 63 of the detection switch 43 continues to rotate due to the rotation of the sub-cam 142, and the rotation angle changes. At 206 degrees, the brush 63 and the first fixed contact es are connected as shown by the dashed line in FIG.
a comes into contact and the fixed terminals asa and esb become electrically conductive, thereby stopping the motor and stopping the rotation of the sub cam 142 and the main cam 162.

At this time, the capstan 72 is rotated clockwise in FIG. 3, and the main idler 76 is rotated counterclockwise in FIG. Therefore, the belt 84, the relay roller 82, and the rotating arm 88 also rotate counterclockwise in FIG. 3, and the idler gear 86 rotating clockwise in FIG. 3 meshes with the take-up reel idler gear 54a. The take-up reel stand 1o is rotated clockwise in FIG.
With the cooperation of the above, the magnetic tape 180 fed at a constant speed is wound around the take-up reel hub 14 without slack, resulting in a recycle mode.

Next, when a stop button (not shown) is pressed, the motor reverses, the sub cam 142 and the main cam 162 start rotating clockwise and counterclockwise in FIG. 4, respectively, and the pinch roller 192 and capstan 72 , and move the tape drawer members 182 and 183 in the direction of the cassette 2o. Additionally, the capstan 72 rotates counterclockwise in FIG. 3, and the idler gear 86 rotates in the supply reel idler gear 64a.
The supply reel base 12 is rotated counterclockwise in FIG. 3, and the magnetic tape that has been pulled out is wound around the supply reel hub 16 without slack. - As shown in FIG. 10, when the main rod 48 is rotated to a rotation angle of 4o0, it already stops moving, and when it is further rotated to a rotation angle of 7°, the sub-rod 130 also stops moving. However, from this state, the sub cam 142 and the main cam 162 continue to rotate, and when the rotation angle reaches o0, the brush 63 of the detection switch 43 and the first
The fixed contact 65c contacts the fixed terminal 69a.

e9b becomes electrically conductive, the motor stops, and the sub cam 142 and main cam 162 also stop rotating. Further, the rotation of the capstan 72 is also stopped, resulting in the stopped state shown in FIG.

As described above in detail based on the embodiments of the present invention, according to the present invention, a cam rotationally driven by a motor;
a moving member that moves to a plurality of positions following the rotation of the cam and switches various operating modes of the device to modes corresponding to each position; a rotating member that rotates in engagement and synchronization with the rotation of the cam; a fixed member provided with fixed contacts corresponding to the plurality of positions; a movable contact portion having a movable contact that is slidable with respect to the fixed member and capable of electrically conducting with the fixed contacts; and the fixed member. a detent means capable of determining the position of the rotating member at an angle such that a fixed contact provided on the member and the movable contact have a predetermined positional relationship; When the movable contact portion rotates due to the rotation of the cam and the movable contact contacts one of the plurality of fixed contacts, the movable contact and the fixed contact The position of the movable member is detected by electrical conduction, and when the cam and the rotating member are engaged by a gear, the cam and the gear portion of the cam are set in a predetermined phase. and providing a first indicator on the rotating member that indicates one tooth ridge or tooth bottom of the rotating member that is in mesh with the cam while being positioned by the detent means,
Since the cam is provided with a second display section that indicates the tooth bottom or tooth ridge of the gear portion of the cam that meshes with the one tooth ridge or tooth bottom, subtle problems in mounting a conventional detection switch can be avoided. Adjustment is no longer necessary, and simply by installing the detection switch in a predetermined position, which easily determines the rotational phase of the rotating member using a detent means, the rotational angle of the cam and the phase of the movable contact part will surely match. Automatic assembly is also possible, which has an extremely significant effect on improving the operating accuracy of the device and reducing costs.Furthermore, the moving member is located at the horizontal part of the cam's lift curve, and its movement stops and the corresponding The cam can be reliably stopped after the cam is in the operating state, and the effects are extremely large, such as enabling highly accurate positioning that is less affected by changes in the load due to changes in the environment or changes over time.

[Brief explanation of the drawing]

FIG. 1 is a surface view of the main parts of an embodiment of the present invention in a stopped mode;
Fig. 2 is a schematic sectional view of the reel drive system, Fig. 3 is a front view of the main parts in the reproducing mode, Fig. 4 is a back view of the main parts in the stop mode, and Figs. A partial sectional view and a plan view showing the installation state, Fig. 7 is a plan view of the main part of the detection switch, Fig. 8 is a sectional view of the main part of the detection switch, Fig. 9 is a plan view of the fixed contact part, and Fig. 10 is a plan view of the main part of the detection switch. The figure is a cam lift curve diagram. 43...detection switch, 45...rotating gear, 48°...main rod, 51...
・Fixed member, 53... Movable contact part, 63...
...Brush, 65...First fixed contact, 71.
...Press pin, 73...Plate spring, 76.
...Groove, 77...1st display section %89, old...2nd display section, 13o...river/sub rod, 142.
River...Sub cam, 162...Main cam. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 5
Figure 6

Claims (2)

[Claims] (1) A cam rotationally driven by a motor, a moving member that follows the cam and moves to a plurality of positions and switches various operating modes of the magnetic tape device to modes corresponding to each position, and a rotating member that engages and rotates in synchronization with the rotation; a fixed member that is provided with fixed contacts corresponding to each of the plurality of positions; and a fixed member that is slidable with respect to the fixed member and that rotates in synchronization with the rotation of the rotating member. A movable contact portion having a movable contact that can be rotated and electrically conductive with the fixed contact, and the rotating member at an angle such that the fixed contact provided on the fixed member and the movable contact have a predetermined positional relationship. and a detent means capable of determining the position of the fixed contact and the movable contact, the detent means being capable of setting the phase relationship between the fixed contact and the movable contact, and rotation of the cam,
When the movable contact portion rotates and the movable contact contacts one of the plurality of fixed contacts, the movable contact and the fixed contact become electrically conductive, thereby changing the position of the movable member. A magnetic tape device characterized in that it is configured to detect. (2) The cam and the rotating member are in a fixed relationship by gears, and the cam and the gear portion of the cam are configured to have a predetermined phase relationship, and the cam is engaged with the cam while being positioned by a detent means. a first display section is provided on the rotating member to indicate one tooth ridge or tooth bottom of the rotating member; Claim O), characterized in that the cam is provided with a second display section indicating the following:
Magnetic tape device described in Section 1.