JPH0322585Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention is a spring formed of a leaf spring material, and is used in, for example, a video tape recorder (hereinafter referred to as
This invention relates to a spring suitable for the front cover spring of magnetic tape cassettes used in VTRs, etc.

[Conventional technology]

As springs used in magnetic tape cassettes for VTRs, coil springs are known, for example, as shown in Japanese Utility Model Application No. 59-149282 and No. 60-89685.

Among these, the former coil spring has a coil part formed in the middle part of the wire, one end is a free end that is locked to the locking protrusion on the front cover, and the other end is detoured to the outside of the lock lever. The end is a free end that presses against the protrusion at the lower end of the lock lever. In addition, the coil spring shown in the latter has a fixed end at one end of the wire that engages with the rotating shaft of the cassette body and rotates together with this rotating shaft, and a rotating shaft continuous to the fixed end. The cassette has a coil portion that is sheathed on the cassette body, and a free end that comes into contact with the stepped portion of the cassette body at the other end.

[The problem that the idea aims to solve]

A coil spring constructed in this way has the problem that when the coil portion made of wire rods expands and contracts by opening and closing the front cover, the wire rods of the coil portions interfere with each other or get entangled with the rotation shaft. A predetermined urging force may not be obtained. In addition, since it is a thin wire, it has the disadvantage of being susceptible to bending and plastic deformation due to reaction forces during assembly and operation.

The present invention was developed in view of the above circumstances, and its purpose is to provide a spring that can always provide a stable biasing force and is less prone to bending or plastic deformation.

[Means to solve the problem]

In accordance with the above-mentioned purpose, the spring of the present invention is a spring formed of a leaf spring material, and
The spring includes a fixed end that is engaged with a slit formed in the rotating shaft, a holding part that extends around the fixed end and surrounds approximately half the circumference of the rotating shaft, and a holding part that is continuous with the holding part. a curved portion that curves in a direction opposite to the curve of the holding portion; and a free end that is supported by another member in continuation with the curved portion and slides on the other member when the rotation shaft rotates. It is characterized by having the following.

[Effect]

According to the above configuration, when the rotating shaft is rotated in the spring winding direction, the portion of the curved portion near the wrapping portion gradually wraps around the outer periphery of the rotating shaft, and the curved portion is elastically deformed as it stretches. Then, the free end slides on the other member toward the fixed end. Next, when the rotational force applied to the rotational shaft is released from this state, the restoring force of the spring causes the portion of the curved portion that wraps around the outer circumference of the rotational shaft near the wrapping portion to The rotating shaft is rotated in the opposite direction to the above while moving away from the member, and the curved part returns to its shape, and the free end also returns to its original position while sliding on the other member in the direction opposite to the fixed end. Then, return the rotating shaft to its original position.

Furthermore, when the rotating shaft is rotated in the direction opposite to the spring winding direction, the holding part gradually separates from the outer periphery of the rotating shaft, and the curved part expands and deforms elastically, pushing the free end. and slide it on another member in the direction opposite to the fixed end. Next, when the rotational force applied to the rotational shaft is released from this state, the restoring force of the spring causes the wrapping part that is separated from the rotational shaft to wrap around the rotational shaft. The rotating shaft is rotated in the opposite direction to the above, and the curved part returns to its original shape, and the free end also returns to its original position while sliding on other members toward the fixed end, and the rotating shaft is rotated. Return to original position.

Furthermore, in both of the above-mentioned actions of the spring, it is also possible to actuate other elements at the bend or at the free end.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

The spring 1 is a spring formed of a plate spring material, and the spring 1 has a fixed end 1a that is engaged with a slit 2a formed in the rotation shaft 2, and a fixed end 1a that is continuous with the fixed end 1a. A holding part 1b that surrounds approximately half the circumference of the rotating shaft 2, a curved part 1c that is continuous with the holding part 1b and curved on the opposite side to the curve of the holding part 1b, and a curved part 1c that is continuous with the curved part 1c. The rotating shaft 2 is supported on a guide surface of another member (not shown).
Free end 1 that slides on the guide surface when rotated
d. Furthermore, the free end 1d is formed into a small arcuate shape that curves opposite to the curve of the curved portion 1c in order to reduce the frictional resistance with the guide surface of other members and to perform the sliding operation smoothly.

The fixed end 1a, the curved part 1c and the free end 1d
are acting parts, and the spring 1
, the fixed end 1a is locked to the rotation shaft 2, and the free end 1d
is supported on the guide surface, and when the rotating shaft 2 is rotated in the spring winding direction from this installed state, the portion of the curved portion 1c near the wrapping portion 1b gradually extends to the outer periphery of the rotating shaft 2. The curved portion 1c is elastically deformed while being wound around, and the free end 1d slides on the guide surface toward the fixed end. Next, when the rotational force applied to the rotational shaft 2 is released from this state, the restoring force of the spring 1 causes the portion of the curved portion 1c that is wrapped around the outer circumference of the rotational shaft 2 near the wrapping portion 1b to While moving away from the surroundings of the rotation shaft 2, the rotation shaft 2 is rotated in the opposite direction to the above, and the curved portion 1c returns to its original shape, and the free end 1d also moves the guide surface in the direction opposite to the fixed end. It returns to its original position while sliding, and the rotation shaft 2 is returned to its original position.

Furthermore, when the rotating shaft 2 is rotated in the anti-spring winding direction, the enclosing portion 1b separates from the outer periphery of the rotating shaft, and the curved portion 1c expands and deforms elastically, pushing the free end 1d. and slide the guide surface in the direction opposite to the fixed end. Next, from this state, the rotation axis 2
When the rotational force applied to is released, the restoring force of the spring 1 causes the wrapping part 1b, which is separated from the rotational shaft 2, to wrap around the rotational shaft 2.
Rotate the rotation shaft 2 in the opposite direction to the above, and
c returns to its original shape, and the free end 1d also returns to its original position while sliding on the guide surface toward the fixed end, thereby returning the rotating shaft 2 to its original position.

Furthermore, in the action of the two springs described above, if necessary, another member can be actuated at the curved portion 1c or the free end 1d.

Next, an application example in which this spring 1 is used in a magnetic tape cassette for a VTR will be explained with reference to FIGS. 2 to 5.

In the figure, Figure 2 is a partially cutaway rear view of the magnetic tape cassette seen from the lower half side, Figure 3 is a cross-sectional view of Figure 2, and Figure 4 is the same as Figure 3 with the front cover opened. FIG. 5 shows a cross-sectional side view of the main part. The magnetic tape cassette 3 has an upper half 4 and a lower half 5 forming a cassette body 6, and a magnetic tape 7 inside the cassette body 6. Supply and take-up reels 8 and 9 for winding the material are rotatably housed. A front cover 10 is attached to the front part of the cassette body 6, which is the side where the VTR is inserted, to cover the magnetic tape 7, which is unwound from the reels 8 and 9 and runs on the front surfaces of the tape guide parts 6a and 6a, in an openable and closable manner. There is.

The front lid 10 is formed in a U-shape in plan with side plates 10c and 10c extending on both sides of a front plate 10a and a top plate 10b, and pivot shafts 11 and 12 protruding from the inside of both side plates 10c and 10c. , side wall 4a of upper half 4,
The front cover 10 is attached to a rotary shaft 11, which is a long shaft, and which is protruded from the inside of one side plate 10c. The spring 1 is installed to maintain the position.

At the corner of the lower half 5 corresponding to the spring 1, a front lid locking member 13 is attached to an upper support shaft 13a,
13a is suspended by the ribs 5a, 5a of the lower half 5, and the front lid locking member 13 is attached to a rotating projecting piece 13b.
is pushed by the curved portion 1c of the spring 1, and a locking projection 13c and a releasing projection 13d are provided to protrude outward from the side wall 5b of the lower half 5, and the locking projection 13c engages with the front cover 10. The lid 10 is held closed.

A slit 14 is bored at the distal end side of the rotation shaft 11, and the spring 1 has the curved portion 1c disposed on the lower half 5 side, the fixed end 1a is locked in the slit 14, and the enclosing portion The free end 1d which is loosely fitted into the guide groove 15 which is formed on the inner surface of the upper half 4 and serves as a guide surface formed on the inner surface of the upper half 4 is brought into contact with the stopper protrusion 16, and the front cover 10 is closed. This front cover 10 is attached to the other rotating shaft 1.
2 and the rotation shaft 11 are mounted in the mounting recess 4b of the upper half 4, and the upper half 4 is mounted.

Then, when the magnetic tape cassette 3 is loaded into the VTR and the front cover 10 is opened, the rotation support shaft 11 that locks the spring 1 moves to the third position as the front cover 10 opens.
The curved portion 1c is rotated in the clockwise direction (spring winding direction) in the figure, and the curved portion 1c is attached to the rotating shaft 11 as shown in FIG.
The portion near the holding portion 1b wraps around the outer periphery of the rotating shaft 2, and the curved portion 1c stretches and moves upwards to separate from the protrusion 13b of the front lid locking member 13, and the free end 1d engages with the stopper protrusion. 16 and slides in the guide groove 15 of the upper half 4 in the direction of the rotation axis.

Next, when the magnetic tape cassette 3 is removed from the VTR and the open engagement of the front cover 10 is released, the restoring force of the spring 1 causes the wrap around the curved portion 1c wrapped around the outer periphery of the rotating shaft 2. While the portion near the holding portion 1b moves away from the periphery of the rotation shaft 2, the rotation shaft 2 is rotated counterclockwise in FIG.
c expands downward and returns to its original shape, while pushing the protrusion 13b of the front lid locking member 13 to engage the locking protrusion 13c with the front lid 10 that has been rotated to the closed position. 10 is held in the initial open state, and the free end 1d slides through the guide groove 15 and comes into contact with the stopper protrusion 16 again.

As described above, the spring 1 used in this application example is capable of contacting the stopper protrusion 16 and rotating the rotation shaft 11.
It combines the three forces of rotation and pushing of the front cover locking member 13, and the number of springs that were conventionally provided for each can be reduced to one, reducing the number of parts and reducing costs. , it is possible to increase the arrangement space and improve the degree of freedom in design.

By the way, in order for the spring to have the desired biasing force, it is necessary to set the thickness and width of the leaf spring material, etc., and also to take a predetermined length. A holding part 1b that holds the rotating shaft 2 approximately half the circumference between the rotating shaft 1a and the free end 1d;
Since the curved part 1c having a curve opposite to the curve of the holding part 1b is continuously formed in a substantially S-shape, a predetermined length can be secured by this curved shape, and the length between the fixed end 1a and the free end 1d can be maintained. The distance is shortened, and the spring 1 can be formed compactly. Also, the amount of elastic deformation due to rotation of the spring 1 is partially absorbed by the expansion and contraction of the curved portion 1c, so the amount of movement of the free end 1d is reduced. It's small enough. Therefore, the space for arranging the spring 1 can be reduced, and the degree of freedom in design can be increased. Further, since the plate spring material can be manufactured by simply cutting and bending the leaf spring material to the required length, it is easy and inexpensive to manufacture.

Furthermore, since it is a strip-shaped leaf spring material that does not have a coil part like a wire rod, it does not interfere with each other on the rotation axes 2, 11 or get tangled with the rotation axes 2, 11, and the predetermined The biasing force can be exerted stably at all times, and bending and plastic deformation are less likely to occur.

The spring of the present invention can be used in a wide range of applications other than the magnetic tape cassette shown in the above application example.

[Effect of idea]

As explained above, the spring of this invention is
a fixed end formed of a leaf spring material and locked in the slit of the rotating shaft; a holding part continuous to the fixed end and surrounding approximately half the circumference of the rotating shaft; and a holding part continuous to the holding part. a curved portion having a curve opposite to the curve of the enclosing portion; and a free end that is supported by another member in continuation with the curved portion and slides on the other member when the rotation shaft rotates. Since it is equipped with a substantially S-shaped curve between the holding part and the curved part, the required length of the spring can be obtained, and the distance between the fixed end and the free end can be shortened, so that the overall length of the spring can be increased. In addition to being able to form a compact spring, the amount of elastic deformation due to rotation of the spring is partially absorbed by the expansion and contraction of the curved part, so the amount of movement of the free end is small, reducing the space for installing the spring. This increases the degree of freedom in design. Further, since the plate spring material can be manufactured by simply cutting and bending the leaf spring material to the required length, it is easy and inexpensive to manufacture.

Furthermore, since it does not have a coil part like a wire rod, it does not interfere with each other on the rotation axis or get entangled with the rotation axis, and it is possible to always stably exert the predetermined biasing force. , and is less prone to bending or plastic deformation.

Moreover, since approximately half the circumference of the rotating shaft is covered by the holding portion, the fixed end can be prevented from coming off from the rotating shaft even if the rotating shaft rotates in any direction. When the rotating shaft rotates in the direction opposite to the spring winding direction, the fixed end can be effectively prevented from coming off.

It is also possible to actuate another member at the curved portion or free end.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the spring of the present invention, Figs. 2 to 5 show examples of its application, and Fig. 2 is a partial cutaway of a magnetic tape cassette seen from the lower half side. 3 is a cross-sectional view of FIG. 2, FIG. 4 is a cross-sectional view of FIG. 3 with the front cover opened, and FIG. 5 is a cross-sectional side view of the main parts. 1... Spring, 1a... Fixed end, 1b...
Wrapped part, 1c...Curved part, 1d...Free end, 2...
... Rotation shaft, 2a ... Slit, 3 ... Magnetic tape cassette, 4 ... Upper half, 4b ... Mounting recess,
5... Lower half, 6... Cassette main body, 7... Magnetic tape, 10... Front cover, 11... Magnetic tape cassette rotating shaft, 13... Front cover locking member, 13b
...Rotation protrusion, 15...Guide groove, 16...
Stotsupa protrusion.

Claims (1)

[Scope of utility model registration request] The spring is made of a leaf spring material, and includes a fixed end that is engaged with a slit formed in the rotating shaft, and a fixed end that extends approximately half the circumference of the rotating shaft. a holding part that holds the holding part; a curved part that is continuous with the holding part and curves on the opposite side to the curve of the holding part; and supported by another member continuously with the curved part;
A spring comprising a free end that slides on another member when the rotation shaft rotates.