JP3439577B2 - Cassette loading device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cassette loading device, and more particularly, to a mechanism of the cassette loading device provided in a device such as a VTR, DAT, camcorder or the like.

[0002]

2. Description of the Related Art VTR (Vidio Tape Recorder), DT
Electrical equipment such as an R (Digital audio Tape Recorder) and a video camcorder is equipped with a cassette loading device that detachably loads a cassette containing a recording medium for recording and reproducing images and sounds. As a cassette loading device, a pop-up system in which a cassette is loaded and unloaded by vertically moving in a direction perpendicular to the surface of the cassette, and a front loading system in which the cassette is loaded in parallel by loading and unloading in parallel are often used.

FIG. 3 is a side view for explaining a conventional pop-up type cassette loading mechanism, and FIG.
Shows the cassette housing in the down position, and FIG. 3 (B) shows the cassette housing in the up position. In the figure, 1 is the main chassis, 2 is the inner link, 3 is the outer link,
Reference numeral 4 is a housing, 5 is a main spring, 6 is a cross link pin, 7 is a damper pinion gear, and 8 is a rack.

A pop-up type cassette loading device is
It has a drive mechanism for vertically driving the housing 4 for loading and holding a cassette (not shown) between an up position and a down position. As a main part of a drive mechanism for driving the housing 4 up and down, an inner link 2 having a hole 2c in the center and an outer link 3 having a hole 3b are provided, and each hole is rotatably supported by a cross link pin 6. Supported X
Cross-link mechanism is used. The X-shaped cross link mechanism has a lower end side supported by the main chassis 1 so as to be movable in the left-right direction according to vertical movement, and an upper end side supports the housing 4 so as to be movable in the left-right direction according to vertical movement of the housing 4. It should be noted that the same pair of cross link mechanisms composed of the inner link 2 and the outer link 3 is provided in the direction of the paper surface, and one cross link pin 6 pivotally supports each cross link mechanism.

The support mechanism between the lower end side of the cross link mechanism and the main chassis 1 includes an outer link shaft 3c having one end fixed to the outer link 3 side in a direction perpendicular to the surface of the outer link 3 and an outer link shaft 3c. The inner shaft 2a is a hole 1a provided in the main chassis 1 that axially supports the inner link 2 side, and one end of the shaft is fixed in a direction perpendicular to the inner link 2, and the inner shaft 2a is guided so as to be slidable in the left and right directions. This is an elongated hole 1b provided in the main chassis 1 for this purpose.

The support mechanism for supporting the upper end of the cross link mechanism and the housing 4 has a shaft 2b having one end fixed to the inner link 2 side in a direction perpendicular to the surface of the inner link 2.
And a hole 4a provided in the housing 4 that rotatably supports the shaft 2b. The outer link 3 side has an outer link guide shaft 4b fixed to the housing 4, and the outer link guide shaft 4b, It is an outer link groove 3a opened in an arc shape in the longitudinal direction at an end portion of the outer link 3 for guiding the upper link in a vertically movable manner.

Spring hooking holes 2d and 3d are provided opposite to each other at the upper ends (housing 4 side) of the inner link 2 and the outer link 3, and both ends of a main spring 5 are hooked in the respective holes. .

FIG. 3 with the housing 4 in the down position.
In the case of (A), the upper shaft 2b of the inner link 2,
The lower shaft 3c of the outer link 3 has a housing 4
Although the shaft 4a is axially supported by the hole 4a of the main chassis 1 and the hole 4a of the main chassis 1, the lower shaft 2a of the inner link 2 is located at the right end of the long hole 1b along the long hole 1b, and the outer link guide shaft 4b of the housing 4 is The inner link 2 and the outer link 3 are located at the left end along the outer link groove 3a.
The ends of each of the two are most apart from each other, and the main spring 5 expands accordingly, and maintains a large spring force P ₁ in the direction of contracting the ends.

FIG. 3 with the housing 4 in the up position.
In the case of (B), contrary to the case of FIG. 3 (A), the spring force of the main spring 5 reduces the distance between the spring hooks 2d and 3d of the inner link 2 and the outer link 3 to reduce the inner shaft 2a.
There outer link shaft 4b to the left end of the slot 1b reaches the right end of the outer link groove 3a, the housing 4 by the spring force of the small spring force P ₂ each end of the inner link 2 and Tauta link 3 is separated smallest Is being lifted up.

In order to prevent the housing 4 from rising and falling abruptly, for example, a damper utilizing the viscous drag of a rotating body rotating in a fluid is provided in the main chassis 1, and the damper is an inner link. A rack 8 fixed to the second inner shaft 2a and moving left and right along the elongated hole 1b;
Braking is performed by utilizing the rotation of the shaft of the pinion gear 7, which rotates in mesh with the rack 8.

Next, in the conventional pop-up type cassette loading mechanism shown in FIG. 3, the moment of the cross link by the inner link 2 and the outer link 3 around the cross link pin 6 for vertically moving the housing 4 will be described.

FIG. 4 is a diagram showing the moment of the cross link around the cross link pin of the conventional cassette loading mechanism, in which the horizontal axis indicates the down position and the up position of the cassette.
The horizontal axis shows the moment of the cross link around the cross link pin.

[0013] In FIG 4, a moment M _D of the down position of the cassette 4 illustrated in FIG. 3 (A), the direction perpendicular to the spring force P ₁ and the cross-link pin 6 to the spring force P ₁ of the main spring 5 acts It is expressed by the product M _D = P ₁ × L ₁ (1) of the length L ₁ in different directions. Further, the moment M _U at up position of the cassette shown in FIG. 3 (B), a spring force P ₂ of the main spring 5, the cross-link pin 6 to the spring force direction and length of the direction perpendicular to P ₂ acts The product of L ₂ is M _U = P ₂ × L ₂ (2), and M _D > M _U as shown.

[0014]

As shown in FIG. 4 [0008] In the conventional cassette loading mechanism, with respect to the spring force P ₁ of the main spring 5 in the down position of the cassette 4, the spring force at the up position P ₂ However, M _D > M _U because of a large change with respect to changes in the lengths L ₁ and L ₂ . in this way,
As the housing 4 rises, the tension of the main spring 5 decreases and a stable rising force of the housing 4 cannot be obtained. Therefore, the rising speed of the housing 4 becomes slower than the descending speed, and in the worst case, the housing 4 reaches the up position. It may not reach. Further, when the housing 4 descends, the force in the ascending direction gradually increases, causing an imbalance in the forces when ascending and descending.

SUMMARY OF THE INVENTION It is an object of the present invention to make a pop-up type cassette loading device always maintain a constant rotation moment with respect to a rotation center of a force acting on a cross link that drives a housing when it is moved up or down.

[0016]

According to a first aspect of the present invention, in a pop-up type cassette loading device, a cross link that rotates around a rotation center is provided for vertically moving the cassette and a housing holding the cassette. The driving force for driving the housing to the up position or the down position is the spring force of at least two springs stretched over the cross link, and the rotational moment of the spring force acting on the cross link with respect to the rotation center is set. By making it constant, the driving force of the cross link that moves the housing to the up position or the down position is made constant so that the up position is always maintained stably.

According to a second aspect of the present invention, in the first aspect of the present invention, the main spring exerts a pushing force only in a direction to push up the housing, and at a down position of the housing, the main spring is hooked above the rotation center, A spring force acts in a direction to reduce the pushing force of the main spring, and when the housing is in the up position, the spring force acts on the lower side of the rotation center, and the spring force acts in a direction to increase the pushing force of the main spring. By using a spring, the housing can be driven with a small force that is approximately equal to the up position and the down position without increasing the spring force of the main spring.

According to a third aspect of the present invention, in the second aspect of the present invention, the cross link is composed of an inner link and an outer link whose central portion is rotatably supported by a cross link pin. Each of the cross links has a lower end side that is rotatable from the center of rotation and is rotatable on the outer link side.
The inner link side is supported by the main chassis so as to be movable in the left-right direction, and the upper end side from the center of rotation is movable upward, downward, left, and right on the outer link side, and rotatable on the inner link side. A housing is supported, the main spring is hooked on the upper ends of the outer link and the inner link, and the auxiliary spring is provided on the lower end side of the main chassis and the inner link in a direction perpendicular to the longitudinal direction of the inner link. The same result as in claim 2 can be obtained by hanging it between a predetermined position.

[0019]

1 is a side view for explaining an embodiment of a cassette loading device according to the present invention.
1A is a diagram when the housing is down, and FIG. 1B is a diagram when the housing is up. In the diagram, 9 is an auxiliary spring, and reference numbers 1 to 8 which are the same as the reference numbers in FIG. This is a part that operates in the same way as the case, and a detailed description is omitted.

In FIG. 1, the auxiliary spring 9 is at a right angle to a straight line connecting the cross link pin 6 and the inner shaft 2a at the lower end portion of the inner link 2 and the hanging hole 1c provided in the main chassis 1. It is hooked between the spring hooking hole 2e of the inner link 2 provided on the protrusion protruding upward. The line of action of the spring force of the auxiliary spring 9 thus hung is located above the center of the cross link pin 6 in the down position of the housing 4 shown in FIG. 1 (A), and is shown in FIG. 1 (B). In the up position of 4,
It is provided below the center of the cross link pin.

In the down position of the housing 4 shown in FIG. 1 (A), the spring force P ₃ of the auxiliary spring 9 causes the shaft 2b of the inner link 2 on the housing 4 side to move to the main spring 5.
It acts in the direction to cancel the spring force P ₁ of the. Moment M _PS of the spring force P ₃ and cross link pin around the 6 inner link 2 includes a spring force P _3, the product M _PS = P ₃ distance L ₃ between the cross-link pin 6 the line of action of the spring force P ₃ × L ₃ (3), which is the moment of the crosslink (P ₁ × x) due to the spring force of the main spring 5 around the crosslink pin 6.
L ₁ ) acts in the direction of decreasing.

On the other hand, in the up position of the housing 4 shown in FIG. 1B, the working line of the spring force P ₃ of the auxiliary spring 9 is below the center of the cross link pin 6, and the spring force P ₃ is the inner force. The shaft 2b of the link 2 on the housing 4 side acts in a direction to be added to the spring force P ₂ of the main spring 5. The spring force P ₄ of the auxiliary spring 9 and the moment M _US of the inner link 2 around the cross link pin 6 at this time are the spring force P ₄ , and the distance L between the action line of the spring force P ₄ and the cross link pin 6. The product of ₄ is M _US = P ₄ × L ₄ (4), which is added to the moment (P ₂ × L ₂ ) of the cross link due to the spring force of the main spring 5.

FIG. 2 is a diagram for explaining the effect of the auxiliary spring according to the present invention, and FIG. 2A is a diagram showing a change in the moment of the cross link around the cross link pin 6 by the auxiliary spring. (B) is a diagram showing the total rotational moment of the cross link by the main spring 5 and the auxiliary spring 9. The horizontal axis represents the movement amount of the housing 4 from the down position to the up position, and the vertical axis represents the total moment M ( X _in ).

When the moment M _S about the cross link pin 6 by the auxiliary spring 9 shown in FIG. 2A is positive when the moment about the cross link pin 6 by the main spring 5 is positive,
−M _DS = (− P ₃ × L ₃ ), and + M _US = in the up position.
(+ P ₄ × L ₄ ), and the moment with respect to the movement of the housing 4 during this time is on the straight line connecting (−P ₃ × L ₃ ) and (+ P ₄ × L ₄ ) as shown in the figure. is there.

The total moment TM by the main spring 5 and the auxiliary spring 9 shown in FIG. 2B is TM _D = (P ₁ × L ₁ )-(P ₃ × L ₃ ) (5 when the housing 4 is in the down position. in), in up _{position, TM U = (P 2 ×} L 2) + (P 4 × L 4) and comprising (6). The adjustment of the moment by the auxiliary spring 9 around the cross link pin 6 to satisfy the expression (6) is performed by moving the position of the locking hole 1c for locking the auxiliary spring 9 of the main chassis 1 up and down. Or by changing the spring force of the auxiliary spring 9.

[0026]

According to the first aspect of the present invention, in a pop-up type cassette loading apparatus, the cassette and the housing holding the cassette have a cross link that rotates around a rotation center to move the housing up and down. Since the driving force for driving to the up position or the down position is the spring force of at least two springs stretched on the cross link, and the rotation moment of the spring force acting on the cross link with respect to the rotation center is constant, The driving force of the cross link that moves the housing to the up position or the down position is kept constant, and the up position is constantly maintained. The effect corresponding to claim 2: With the main spring in which the pushing-up force acts only in the pushing-up direction of the housing and the down position of the housing,
A spring force acts on the upper side of the rotation center to reduce the pushing force of the main spring, and when the housing is in the up position, the spring force acts on the lower side of the rotation center to increase the pushing force of the main spring. Since the auxiliary spring exerts a spring force in the direction, the housing can be driven with a small force substantially equal to the up position and the down position without increasing the spring force of the main spring. Effect corresponding to claim 3: The cross link is composed of an inner link and an outer link whose central portion is rotatably supported by a cross link pin, and the cross link has a lower end side from a rotation center,
The outer link side is rotatably supported, and the inner link side is horizontally movably supported by a main chassis, and the upper end side from the rotation center is movable upward, downward, left, and right on the outer link side. , Rotatably supporting the housing on the inner link side, hooking the main spring on the upper ends of the outer link and the inner link, the auxiliary spring on the main chassis, and the inner link on the lower end side of the inner link. Since it is applied to a predetermined position defined in the direction orthogonal to the lengthwise direction of, the same result as in claim 2 can be obtained.

[Brief description of drawings]

FIG. 1 is a side view for explaining an embodiment of a cassette loading device according to the present invention.

FIG. 2 is a diagram for explaining an effect of an auxiliary spring according to the present invention, FIG. 2 (A) is a diagram showing a change in a moment of a cross link around a cross link pin by the auxiliary spring, and FIG. FIG. 6 is a diagram showing a total rotation moment of a cross link by a main spring and an auxiliary spring.

FIG. 3 is a side view for explaining a conventional pop-up type cassette loading mechanism.

FIG. 4 is a diagram showing a moment of a cross link around a cross link pin of a conventional cassette loading mechanism.

[Explanation of symbols]

1 ... Main chassis, 2 ... Inner link, 3 ... Outer link, 4 ... Housing, 5 ... Main spring, 6
... Cross link pin, 7 ... Pinion gear for damper, 8 ...
Rack, 9 ... Auxiliary spring.

Claims (3)

(57) [Claims] 1. A pop-up type cassette loading apparatus having a cross link that rotates around a rotation center for vertically moving a cassette and a housing holding the cassette, and drives the housing to an up position or a down position. A cassette loading device, wherein a driving force is a spring force of at least two springs stretched around the cross link, and a rotation moment of the spring force acting on the cross link with respect to the rotation center is constant. 2. The main body spring, which is stretched around the cross link, applies a pushing force only in a direction of pushing up the housing, and when the housing is in a down position, the spring is hung above the center of rotation and A spring force acts in a direction to decrease the pushing force of the spring, and when the housing is in the up position, it is hung below the center of rotation and has an auxiliary spring that acts in a direction to increase the pushing force of the main spring. The cassette loading device according to claim 1, wherein the cassette loading device is configured as follows. 3. The cross link is composed of an inner link and an outer link whose center portion is rotatably supported by a cross link pin, and the cross link has a lower end side from a rotation center, and the outer link is the outer link. Rotatably, the inner link side is supported by the main chassis so as to be movable in the left-right direction, and the upper end side from the rotation center is movable up, down, left, and right on the outer link side, respectively.
The inner link side rotatably supports the housing, the main spring is hooked on the upper ends of the outer link and the inner link, and the auxiliary spring is attached to the main chassis and the inner link at the lower end side of the inner link. The cassette loading device according to claim 2 , wherein the cassette loading device is hung between a predetermined position defined in a direction perpendicular to the length direction and above.