JPS6376929A - Torsion spring device - Google Patents

Abstract

PURPOSE:To steadily assemble a torsion spring by sizing the coil part of a torsion spring supported by a shaft in its inner diameter partially equal to or smaller than the diameter of said shaft, and its end side continuing on an actuating arm larger than said diameter. CONSTITUTION:A torsion spring device 1 is composed of a shaft 3 projecting from a movable body 2a end a torsion spring 4 assembled with said shaft 3. said torsion spring 4 is formed of 8 coil part 4a and arm parts 4b, 4c extending from its both ends respectively. The coil part 4a is fitted around the root 3a of the shaft 3, and the one end arm 4b abuts on the locking piece 5 of a movable body 2a, and the end of the other end arm 4c on a fixed body 2b respectively. In this case, the first winding turn 4a1 continuing on the one end arm 4b of the coil part 4a is formed in its inner diameter smaller than the diameter of said root 3a, and the second and third winding turns 4a2, 4a3 are formed in their inner diameters to keep larger than the diameter of the shaft 3 even when the other end arm 4c operates to reduce said inner diameters.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a torsion spring device.

[Summary of the invention]

The present invention enables the tension spring to be stably assembled to the shaft by forming a part of the coil portion of the torsion spring to a diameter that allows it to be lightly press-fitted to the shaft. .

[Conventional technology]

Torsion spring devices are widely used as even-odd members of movable parts in various devices, such as the one disclosed in ``Utility Model Application Publication No. 61-57, 376''.
Some tape cassettes, particularly tape cassettes used for recording and reproducing PCM, are equipped with torsion springs.

That is, this tape cassette has a slider for opening and closing a recess for inserting a tape loading guide provided on the lower surface of the cassette case, and a member for biasing the slider in the closing direction when the tape cassette is not in use. A torsion spring is used.

This torsion spring is formed in a so-called cantilever shape consisting of a coil portion and an arm extending from one end of the coil portion, and the coil portion is loosely inserted into a shaft provided in the cassette case.
In addition to locking and fixing in the groove formed in the shaft at the end,
By bringing the ends of the arms into white contact with the slider, a biasing force is applied to the slider in the direction of closing the four parts.

In such torsion springs, the diameter of the coil part is set larger than the diameter of the shaft in advance, taking into account that when the slider slides open, the arm part operates against the elastic force and the diameter of the coil part is narrowed. The torsion spring is therefore assembled with a clearance between the coil portion and the shaft.

[Problem that the invention seeks to solve]

In this way, conventional torsion springs have a clearance between the coil part and the shaft, so they cannot be assembled to the shaft in a stable state, and the slider slides in the opening direction, causing the torsion spring to open. When the arm operates, the entire torsion spring is tilted with respect to the axis, and as a result, the contact position of the end of the arm against the cassette cassette is shifted from its normal position, causing some of the end There is an inconvenience that the slider gets stuck in the gap between the cassette case and the slider, making it difficult for the slider to slide smoothly.

The present invention has been made in view of the above, and an object of the present invention is to provide a torsion spring that can be assembled in a stable state without tilting with respect to an axis.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a torsion spring device in which a coil portion of a torsion spring is passed through a shaft and supported. It is formed to have a diameter that is approximately the same as or 2 smaller than the diameter of the shaft, and the end side of the coil portion that is continuous with the operating arm, that is, the second and third windings, is formed to have a diameter that is larger than the diameter of the shaft. It is.

[Effect]

By forming the first turn of the coil part to have a diameter that is approximately the same as or smaller than the diameter of the shaft, when the torsion spring is attached to the shaft, the coil part is fitted into the shaft in a light press-fit manner. The torsion spring can be assembled in a stable state without tilting with respect to the axis. When the arm part of the torsion spring is activated, the diameter of the second and third coil parts is affected, but since the diameter of this coil part is larger than the diameter of the shaft, the torsion spring is activated. The arm will be operated without any hindrance.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

(1) shows the torsion spring device of the present invention as a whole, and this torsion spring device (1) includes a shaft +31 protruding from a movable body (2), and a torsion spring (4) assembled to this thin body (3). ), and the shaft (3) is at its base (
3a) is formed in a straight cylindrical shape with the same diameter over the required height, and the upper end (3a) is formed in a tapered shape for easy assembly of the torsion spring (.1). The shape of this shaft (3) may be entirely tapered as shown in FIG.

The torsion spring (4) is formed by a coil part (4a), and arm parts (4b) and (4) extending from both ends of the coil part (4a), and the coil part (4a) is connected to the base of the shaft (3). (3a), and move one end arm (4b) to the movable body (2Q
), and the terminal of the other end arm (4C) is brought into contact with the end face side of the fixed body (2b), whereby the movable body (2a) The mechanism is configured such that the mechanism is slidably biased in a direction that is spaced apart from a constant force.

Coil C15 (4a) of this torsion spring (4)
) Partially formed with different diameters. That is, although the coil part (4a) is formed by winding a plurality of times (approximately three times in this example), the movable body (2a))
The inner diameter cil of the first roll (4al) that is continuous with 4b) is the axis (
3) formed to have a diameter slightly smaller than the diameter d of the root portion (3a),
Inner diameter d2 of the second roll (4a2) and third roll (4a3) of the bata
As the movable body (2a) 7) slides, a part of the other end (4C)
A diameter that takes into account that the diameter is narrowed when the arm tilts toward the arm (4b) at one end against the elastic force, i.e.,
It is formed so that the diameter is larger than the diameter d of the shaft (3) even if the other end arm (4C) is operated and the diameter is narrowed.

The torsion spring (4) formed in this way is attached to the shaft (3).
When the coil part (4a) is attached to the
4ax) is fitted into the base portion (3a) of the shaft (3) in a light press-fit manner, so that the torsion spring (4) is stably assembled to the shaft (3).

Next, an application example of the torsion spring device of the present invention configured as described above will be explained. In this example as well, a case will be described in which the torsion spring device of the present invention is applied to a tape cassette, similar to the conventional example described above.

In the figure, αυ indicates the entire tape cassette, especially a tape cassette used for PCM recording and playback, and α2 indicates the cassette case, and the upper and lower halves of this cassette case az (
A pair of reel hubs uQ on which the magnetic tape α9 is wound are housed in 13■, and the magnetic tape (151) is led out from the reel hub U via the left and right tape guides (17) and attached to the cassette case α2. Facing the front part.0I
Reference numeral 19 denotes a front Ifi lid that covers this magnetic tape lead-out part. When the tape cassette is in use, it is rotated upward to open the magnetic tape lead-out section.

In addition, on the front lower surface of the lower half circle, there is a recess (l! A guide system for tape loading from a recording/playback device is inserted into this concave pronunciation for recording or playback.

(to) is the cassette case α so as to close this recess σ].
This is a slider that is attached to the bottom side of the lower half I of 2 so as to be slidable in the front and back direction.The front part of this slider (A) has front and rear lock holes ( 21a) (21b) are drilled, and an elastic lock opening is provided on the lower surface of the lower half (1 piece) corresponding to the lock hole (21a) (21b), and a slider (
At the front and rear sliding ends of 21, lock holes (21b) (
21a) of the locking pieces, the sliders GG are held in their respective locking positions.

At the front end of this slider (A), there is a torsion spring device 1tl of the present invention as a member that biases this slider 4 always forward, that is, in the direction of closing the recess (11).
is provided. That is, slider C as an excitable body
A shaft (3) is protruded from the center of the front end of 2G, and this shaft (3)
Fit the coil part (4a) of the torsion spring (4) into the
One end of the arm (4b) is attached to the front end of the slider (3)
The lower half I as a fixed body is fixedly fixed to the locking piece (5) formed adjacent to the lower half I, and the other end arm (4C) is inclined inward against the elastic force. Front wall (14a)
It is in contact with.

As a result, the biasing force of the torsion spring (4) acts between the slider shaft (3) and the front wall (14a) of the lower half U, so that the slider is held in the cassette case 0.
When the tape cassette is not in use, the tape cassette is always slid forward and the recess α→ is closed. In this state, the lock piece 1) 21 is engaged with the rear lock hole (21b), thereby locking the slider. The CQ is maintained in this blocked state.

When this tape cassette is loaded into a recording/reproducing device from an unused state, that is, a stored state, the lock piece is pressed from below by the mechanism of the recording/reproducing device, and the lock piece is released from the lock hole (21b). At the same time, the slider 4 is slid backward against the biasing force of the torsion spring (4) to open the recess α■, and in this state, the lock piece (22) is engaged with the front lock hole (21a). By this, slider B(J) is held in this open state.

When the slider -■ is slid open, the other end arm (4c) of the torsion spring (4) acts to further incline inward against the elastic force, and this other end arm (4C) The third winding (4a3) and the second winding (4az) of the coil part (4a) that are continuous with this will be in a state where it is squeezed, but the coil parts of these second and third windings (4az) and (4a3) are +tqlIt.
31, so even if its diameter is reduced, it will still be larger than the diameter of the shaft (3),
Therefore, the other end arm (4c) of the torsion spring (4) is operated without any hindrance, and the slider (2A) is smoothly slid backward.

Furthermore, when the tape cassette is taken out from the recording/playback device in this state, the lock piece is pressed from below by the mechanism on the recording/playback device side during this taking-out operation, and the lock hole (21
The engagement with a) is released, and therefore the slider 4 slides forward by the biasing force of the torsion spring (4), and the recess .alpha..sub.2 is closed as described above, and the tape cassette is placed in the preserved state.

The tape cassette equipped with the torsion spring device of the present invention configured and operated in this manner has a torsion spring (4).
The coil part (4a) of the shaft (3) is lightly press-fitted, so that the torsion spring (4) is attached to the shaft (3).
Since the torsion spring (4) can be assembled in a stable state against the shaft (to) when the slider (to) slides like in the past, the torsion spring (4)
3) tilted downward/'-7 (141 front side 1 (14
The contact position of the other end arm (4C) with respect to a) does not shift, and therefore the torsion spring (4) acts as a slider.
Since a biasing force can be reliably applied to the slider (A), the slider (A) can slide smoothly. Also, in this way, the torsion spring (4) can be stably assembled without tilting with respect to the shaft (3). By doing so, the other end arm (4C) will not fit between the lower half (14+ and the slider -■) and the slider (to) will not rise above the lower surface of the lower half U4. The lock piece (2) and the lock hole (2La) (21) of the slider 4 are securely engaged, so that the slider (2) is firmly maintained in the locked state with the recess tl'l closed and opened. become.

Furthermore, the torsion spring device +1+ in this example has a shaft (
3) Lightly press fit the coil part (4a) into both end arm parts (4b).
and (4C) respectively to slider 4 and cassette case (1).
Since it is assembled by locking the torsion spring on the shaft (3), there is no need to form a concave groove for locking the torsion spring on the shaft (3) as in the conventional example described above. It also has the effect of reducing production costs without complicating the molding die.

This torsion spring equipment again! (1) is the other end arm (4C
) Even if the diameter of the third winding (4a2) and the third winding (4aa) of the coil part (4a) is narrowed by the operation of The operating range of the arm (4C) is expanded, and a sufficient sliding bias force can be applied to the slider (2G).

In addition, in this embodiment, one end arm portion (4) of the torsion spring (4)
b) is the fixed arm, the other end arm (4C) is the operating arm, and the -th turn (4) of the coil part (4a) continuous with the fixed arm
a1) is formed to have a small diameter so that it can be lightly press-fitted into the cap (3), and the third roll (a1) whose diameter is narrowed by the operation of the operating arm.
4az) and the third winding (4a3) are formed to have a larger diameter than the shaft (3), but a winding in which both end arms (4b) and (4C) are actuated arms is as follows: Arms at both ends (4
- of the coil portion (4a) continuous to b) and (4C), respectively.
The winding (4as) and the third winding (4aa) are formed to be thicker than the shaft (3), and the third winding (4a2) sandwiched between them is formed into a shaft (4a2).
3), it may be formed to have a small diameter so that it can be lightly press-fitted.

In addition, in the above embodiment, the inner diameter of a part of the coil part (4a) is formed to be slightly smaller than the diameter of the shaft (3), so that the coil part (4a) can be easily press-fitted into the shaft (3). Even if the inner diameter of a part of this coil part (4a) is formed to be approximately equal to the diameter of the shaft (3), the coil part (4a) can be lightly press-fitted into the shaft [31] in the same way. It is fitted in a shape.

Furthermore, this embodiment shows an example in which the present invention is applied to a so-called double-end-shaped torsion spring (4) whose both end arms (4b) and (4 arms) are respectively latched to the slider (2) and the cassette case az. However, the present invention is not limited to this, and can also be applied to, for example, the so-called cantilever-shaped torsion spring used in the conventional example described above.

Further, in this embodiment, an example in which the torsion spring device of the present invention is applied as a biasing member of a slider of a tape cassette for recording and reproducing PCM is shown, but the torsion spring device of the present invention can be used in other ways, such as the present invention. It can also be used as a member to always bias the front cover of the tape cassette shown in the embodiment in the closing direction, and furthermore, it can be widely applied to the movable parts of various im-devices other than this tape cassette.

〔Effect of the invention〕

As described above, in the torsion spring device of the present invention, a part of the coil of the torsion spring is formed to have a diameter that is approximately the same as or smaller than the diameter of the shaft, and at least the end side of the coil part that is continuous with the operating arm part has the diameter of the shaft. By forming the torsion spring to a larger diameter, when the torsion spring is attached to the shaft, the coil part fits into the shaft in a light press-fitting manner, and therefore the torsion spring remains stable without falling. Since it is assembled, the biasing force of the torsion spring can be reliably applied to the movable member, and stable operation can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the torsion spring device of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, Fig. 3 is an explanatory diagram of the dimensional relationship between the shaft and the torsion spring, and Fig. 4 is a diagram of the shaft. 5 is a partially cutaway perspective view of the tape cassette equipped with the torsion spring of the present invention, FIG. 6 is a plan view of the tape cassette with the upper half removed, and FIG. 7 is a sectional view showing the other side. FIG. 3 is an exploded perspective view of the lower half and slider of the same. In the figure, (3) is the shaft, (4) is the torsion spring, (4a)
is a coil portion, and (4b) and (4C) are arm portions.

Claims (1)

[Scope of Claims] A torsion spring device in which a coil portion of a torsion spring is supported through a shaft, wherein a part of the coil portion is formed to have a diameter substantially equal to or smaller than the diameter of the shaft; A torsion spring device characterized in that at least an end portion of the coil portion that is continuous with the operating arm portion is formed to have a diameter larger than the diameter of the shaft.