JPH079219Y2 - Break mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an improvement of a brake mechanism suitable for a reel stand of a tape recorder, and more specifically, to stop or fast-forward or wind a tape at a constant speed. The present invention relates to a brake mechanism suitable for a reel stand of a tape recorder or the like, which can generate a braking force required for stopping from the returning time by a tightening force of a toothed rubber link fitted with a constant tension on a reel shaft. It is a thing.

[Prior Art] For example, as a brake function for a reel stand of a tape recorder, when fast-forwarding, rewinding, or switching from a play state to a stopped state, abnormal tension is applied to the tape as quickly and reliably as possible, It is to stop the tape running so as not to loosen. Then, in order to stop the running tape so as not to slacken, it is necessary to always exert a stronger braking force on the supply-side reel base than on the winding-side reel base.

Here, an example of a conventional technique used for a brake mechanism of a reel base of a tape recorder will be briefly described with reference to FIG. FIG. 8 is a plan view showing an example of a brake mechanism that is differentially operated by a cam used in a tape recorder. In the drawings, parts similar to those in FIGS. 1 to 7 and parts having similar functions in these figures are denoted by the same reference numerals, and description thereof will be omitted.

In this figure, the brake lever 11 is constantly pressed against the outer peripheral surface of the assist cam 28 by the elastic force of the compression spring 29. The assist cam 28 is driven by a motor (not shown) and rotated to a designated position in each mode such as constant speed feeding, fast feeding, rewinding, and stopping. Then, at the time of feeding and rewinding, the convex portion of the assist cam 28 contacts the brake lever 11 and pushes up the brake lever 11 against the compression spring 29 to release the engagement between the brake shoes 30S, 30T and the reel bases 2S, 2T. At the time of stop, the recess of the rotated assist cam 28 comes into contact with the brake lever 11 as shown in the figure, and the brake shoes 30S, 30T are pressed against the reel bases 2S, 2T to apply the brakes.

[Problems to be Solved by the Invention] However, in the configurations shown in the above examples,
In the brake mechanism shown in FIG. 8, the braking force is determined by the force of the compression coil spring, the radius of the reel stand, and the friction coefficient between the reel stand and the rubber. The outer circumference of the reel stand that is inevitably stable and that comes into contact with the brake shoes is generally knurled in the case of a reel take-out drive mechanism using an idler pulley, and the reel stand drive is driven by a gear. In the case of the mechanism, the tooth profile is naturally engraved. Therefore, the brake shoe pressed against the reel stand has a drawback that it is easily worn. Furthermore, since the elastic force of the compression spring constantly acts on the assist cam, the force of the compression spring increases the load of the driving force for rotating the assist cam, resulting in an increase in power consumption. .

The present invention has been made to eliminate the above-mentioned drawbacks existing in the same kind of conventional mechanism. Therefore, a first object of the present invention is to increase the radius of a brake such as a reel stand and to increase the radius of a brake shoe. (EN) Provided is a brake mechanism capable of obtaining a large braking force without enlarging the contact area of or of the spring or increasing the elastic force of a spring that generates a pressure contact force of a brake shoe.
Further, a second object of the present invention is to generate a braking force not by an elastic force of a spring but by a tightening force of a brake rubber which is directly inserted into a device such as a reel shaft for applying a brake and is large in size. It is to provide a brake mechanism having a reliable brake ratio. Still further, a third object of the present invention is to provide a brake having a slip mechanism in the brake rubber itself without allowing the slip mechanism of the brake to be performed by the rotation transmission section of the reel stand or by providing a separate limiter. To provide the mechanism.

[Means for Solving the Problems] In order to achieve the above object, the brake mechanism according to the present invention is rotatably fitted to a shaft of a rotating body such as a reel stand and has a contact surface with the shaft. Is a slip surface, and a toothed brake lever that engages with the teeth of the toothed rubber ring and locks its rotation is engaged. That is, the teeth of the toothed rubber ring fitted with a constant tension on the outer periphery of the body of the collared sleeve that is press-fitted and fixed to the one for braking such as a reel shaft integrated with the reel base, and the teeth formed on the brake lever. The means for generating the brake torque by the engagement of the above is adopted.

[Operation] In the brake mechanism of the present invention configured as described above, the teeth of the toothed rubber ring and the brake lever that are fitted to the collar sleeve fixed to the reel shaft so as to have a constant tension are formed. Since the brake is applied by the engagement with the teeth, the teeth of the brake lever can automatically bite between the teeth of the toothed rubber ring to obtain a very large braking force, and at the same time, the brake can be applied. It is not necessary to separately arrange a drum, and it is not necessary to increase the diameter of the reel base or the contact area of the friction portion in order to increase the braking force. Further, the setting of the braking force has conventionally been performed by a complicated combination of various factors such as the force of the pressure contact spring, the diameter of the reel stand, the contact area of the friction portion, and the friction coefficient. Since the tension and hardness of the rubber of the attached rubber ring and the shape of the claw can be dealt with, the setting and adjustment of the braking force can be facilitated. In addition, since the outer peripheral surface of the reel stand is not directly used as the contact surface of the friction portion, it is possible to prevent the performance from being deteriorated due to dust, powder, etc. generated by abrasion from the contact member on the outer peripheral surface of the reel stand. .

[Embodiment of the Invention] Hereinafter, the present invention will be described in detail with reference to an embodiment shown in FIGS. 1 to 7. 1 is a plan view showing an embodiment of a brake mechanism according to the present invention, showing a normal state in which a brake is not activated, FIG. 2 is a plan view showing a state in which the brake is activated, FIG. Is a plan view showing the rubber ring with teeth, FIG. 4 is a side view showing a partial cross section of the brake torque generating mechanism, and FIG. 5 is a graph showing slip characteristics when torque in the biting direction is generated. Sixth
FIG. 7 is a graph showing a brake torque characteristic when a brake torque is generated when a torque in the escape direction is generated, and FIG. 7 is a perspective view showing an example in which the brake mechanism of the present invention is applied as a limiter mechanism.

In these figures, 1S is a supply reel shaft, 1T is a take-up reel shaft, 2S is a supply reel stand fixed to the supply reel shaft 1S, and 2T is a take-up reel stand fixed to the take-up reel shaft. Is. The supply reel shaft 1S and the take-up reel shaft 1T are located at a substantially intermediate position between these two shafts in the drawing.
With the rotation of the reel motor pulley 4 fixed to the reel motor rotation shaft 3 shown by the dotted line, the rotation is transmitted to one of the reel shafts via the idle gear 6 and the like fixed to the idler column 5. Then, by the transmitted rotation, one of the reel bases 2S and 2T rotates in each mode, and the winding or rewinding operation of the tape wound on each reel base is performed. Since it is the same as a conventionally known one, detailed description thereof will be omitted.

Brake torque generating mechanisms 7S and 7T, which will be described in detail later, are respectively provided on the lower side of each of the supply reel base 2S and the take-up reel base 2T (when viewed from a direction perpendicular to the paper surface of FIG. 1). Press-fitted and fixed to 1T. The brake torque generating mechanism 7 is composed of a toothed rubber ring 8 having a ratchet-like tooth on the outer periphery shown in FIG. 3 and a collared sleeve 9 shown in FIG. The outer diameter d ₁ of the fitting hole formed in the center is the outer diameter of the body of the collar sleeve 9.
Since it is set smaller than d ₂ , the toothed rubber ring 8
Will be inserted into the body of the collared sleeve 9 in a state of being expanded in the radial direction. At the time of this insertion, a lubricant such as molybdenum or oil or grease is applied between the body of the toothed rubber ring 8 and the collared sleeve 9. Therefore, the toothed rubber ring 8 is configured to be in pressure contact with the body portion of the collared sleeve 9 with a constant tension and to easily cause a slip when a certain torque or more is applied by applying the lubricant. There is. The brake torque generating mechanism 7 assembled as described above is connected to the supply brake torque generating mechanism 7S and the take-up brake torque generating mechanism 7T by traversing the teeth of the toothed rubber ring 8 which is a component thereof. Be divided. That is, the supply brake torque generating mechanism 7S is composed of a toothed rubber ring 8S having a tooth shape that bites when rotating counterclockwise, and the take-up brake torque generating mechanism 7T has teeth that bite when rotating clockwise. The toothed rubber ring 8T having the shape of The collar of the collar sleeve 9 serves not only to prevent the toothed rubber ring 8 fitted into the collar sleeve 9 from falling off but also to prevent the reel bases 2S and 2T from falling out.

On the other hand, on the left side of the supply brake torque generating mechanism 7S and on the right side of the winding brake torque generating mechanism 7T, the supply brake lever shaft 10S and the winding lever shaft 10T are planted in a frame (not shown), respectively. The supply brake lever shaft 10S has a V-shaped brake lever 11S, and the take-up brake lever shaft 10T has a brake lever 11T of substantially the same shape rotatably fitted therein. The brake lever 11S,
Collars 12S and 12T are fixed to portions of the 11T that are fitted into the brake lever shafts 10S and 10T, and spring hooks 13S and 13T are fixed to the other ends of the collars 12S and 12T, respectively. Further, the opposite sides of the brake levers 11S, 11T to the spring hooks 13S, 13T are extended so as to engage with the counterpart brake torque generating mechanism and the tips of the brake generating mechanisms 7T, 7S are respectively engaged at their tips. Toothed rods 15S and 15T having tooth shapes of the rubber rings 8T and 8S and meshing teeth 14S and 14T engageable with one rotation are formed.
Further, tension coil springs are provided between the spring hooks 13S and 13T and the side plates of the frame (not shown).
16S and 16T are stretched, and the coil springs 16S and 16T
Constantly supplies the brake lever 11S with the supply brake lever 10S
In the counterclockwise direction around the center, the brake lever 11T is provided with rotational habits in the clockwise direction around the take-up brake lever shaft 11T. The take-up brake torque generating mechanism 7T and the supply brake torque generating mechanism are respectively provided.
It is released from the engagement with 7S. Furthermore, the brake lever 11T is extended forward and bent at the tip,
The solenoid (17) has an operating piece (19) slidably fitted in a plunger (18). The tip of the plunger 18 has a collar 20, which is a stopper 21 fixed to the frame when the plunger 18 is not sucked.
And a clockwise rotation range of the brake lever 11T is restricted. Further, a pin 22 is planted near the supply reel shaft 1S of the toothed rod 15T of the brake lever 11T, and the pin 22 abuts the side edge 23 of the toothed rod 15S of the brake lever 11S, The counterclockwise rotation range of the toothed rod 15S is controlled via the toothed rod 15T whose clockwise rotation range is regulated by 18.
In the embodiment of the present invention, the position of the pin 22 is set near the supply reel shaft 1S, so
When 18 is operated, the toothed rods 15S and 15T respectively wind up the brake torque generating mechanism 7T and the supply brake torque generating mechanism 7S.
The toothed rod 15S is always a toothed rod 15T so that it can be engaged at the same time.
It goes without saying that the rotation angle up to the rearward position, that is, the winding brake torque generating mechanism 7T is set to be large.

The operation of the embodiment of the present invention having the above structure will be described with reference to FIGS. The solenoid 17 is not energized while the tape is running, so the plunger
18 is not sucked, so that the brake lever 11T is pulled by the tension spring 16T and the operating piece 19 causes the plunger 1 to move.
The collar 20 of 8 is rotated clockwise around the take-up brake lever shaft 10T until it comes into contact with the stopper 21, and the brake lever 11S is indexed by the tension spring 16S so that the side edge 23 of the toothed rod 15S is Brake lever 11T toothed rod
It is rotated counterclockwise about the supply brake lever shaft 10S until it comes into contact with the pin 22 of the 15T. That is, while the tape is running, as shown in FIG.
The engaging tooth 14S of the toothed rod 15S of S does not engage the tooth of the toothed rubber ring 8T of the take-up brake torque generating mechanism 7T, and similarly, the engaging tooth 14T of the toothed rod 15T of the brake lever 11T also supplies the brake torque. It does not engage with the teeth of the toothed rubber ring 8S of the generating mechanism 7S. Therefore, the reel shafts 1S and 1T can freely rotate without any braking during the rotation.

Next, stop or fast forward from the constant speed feeding of the tape,
When stopping the tape running such as stopping after rewinding, the solenoid 17 is excited by a switch (not shown) for each mode to attract the plunger 18 in the direction of the arrow in FIG. The brim 20 of the plunger 18 also presses the operating piece 19 of the brake lever 11T in the arrow direction. As described above, the brake lever 11T is wound up against the tension coil spring 16T every time the solenoid 17 operated each time the switch of each mode is operated and the plunger 18 attracted by the operation of the solenoid 17 is operated. Axis 10T
Is rotated in the counterclockwise direction about its center, and the meshing tooth 14T of the toothed rod 15T engages with the tooth of the toothed rubber ring 8S of the supply brake torque generating mechanism 7S. Also, the brake lever 11T
The brake lever 11S is also rotated clockwise around the supply brake lever shaft 10S against the tension coil spring 16S by the pin 22 in conjunction with the operation of the toothed rod 15S.
The meshing tooth 14S of is engaged with the tooth of the toothed rubber ring 8T of the winding brake torque generating mechanism 7T. As described above, when the tape is stopped, the brake levers 11S and 11T are rotated and engaged with the opposed toothed rubber rings 8T and 8S, respectively, but as described above, the toothed rubber rings 8T and 8S are engaged.
Since the direction of the teeth of is set to the opposite direction, a brake ratio can be provided between the supply side and the winding side brake torque generating mechanisms 7S and 7T.

The operation of generating the above brake ratio will be described below.For example, when the tape is wound on the take-up reel base 2T, the take-up reel shaft 1T and the take-up brake torque generating mechanism 7T rotate counterclockwise. The supply reel shaft 1S and the supply brake torque generating mechanism 7S are also rotating counterclockwise at the same time. Now, as described above, the toothed rods 15T and 15S are pressed against the opposed toothed rubber rings 8S and 8T by the stop signal. Then, at this time, on the delivery side, the meshing teeth 14T of the toothed rod 15T engages with the toothed rubber ring 8S to prevent rotation of 8S, so 8S does not rotate together with 1S and the supply brake torque generation mechanism 7S A slip torque is generated between the collared sleeve 9 and the toothed rubber ring 8S. on the other hand,
On the take-up side, the meshing teeth 14S and the toothed rubber ring 8T of the toothed rod 15S are set in the escape direction, so that the toothing 14S slides and rotates while riding on the teeth of the toothed rubber ring 8T. On the winding side, a brake torque smaller than the slip torque between the collar sleeve 9 and the toothed rubber ring 8S described above can be obtained. In addition, the tape supply reel stand 2S
In the case of rewinding and rewinding, the supply reel stand on the take-up side is the same as in the case of the above-mentioned winding.
The 2S side becomes the escape direction, and the take-up reel stand 2T side that is the sending side becomes the eating direction, so that a reliable brake ratio can be obtained.

Further, the magnitude of the brake torque that is increased is the relationship between the hardness of the toothed rubber ring 8 and the inner diameter d ₁ of the fitting hole of the toothed rubber ring 8 and the outer diameter d ₂ of the body of the collared sleeve 9, that is, the tooth. The characteristic of the slip torque when engaged is shown in FIG. 5, and the characteristic of the brake torque in the escape direction is shown in FIG. 6, which is determined by the tension of the rubber ring 8. FIG. 5 shows the rubber tension ratio when the inner diameter d ₁ of the fitting hole of the toothed rubber ring 8 is made smaller than the outer diameter d ₂ (constant) of the body portion of the collared sleeve 9 on the horizontal axis ( The right is a small d ₁ ), and the graph shows the braking torque on the vertical axis. As can be seen from this graph, when the rotation of the toothed rubber ring 8 is locked, the larger the rubber tension is, the larger the rubber tension becomes. Brake torque is obtained. Further, FIG. 6 shows the characteristics of the brake torque in the escape direction when the shape of the toothed rubber ring is made constant and the rubber hardness is increased, with the rubber hardness on the horizontal axis and the brake torque on the vertical axis. As you can see from this graph, when the rubber hardness is high, the teeth of the brake lever must be completely released by the teeth of the toothed rubber ring, so the braking torque is large, whereas the rubber hardness is When it becomes lower, the tooth portion of the toothed rubber ring is bent and the toothed rubber ring can slide and rotate even if the brake lever does not completely escape, so the brake torque becomes small.

An example of applying the present invention as a simple limiter mechanism is shown in FIG. In this figure, reference numeral 8 denotes a toothed rubber ring 8 inserted into a collared sleeve 9 fixed to the output shaft 24. The toothed rubber ring 8 and the collared sleeve 9 form a pair to generate a brake torque. The mechanism 7 is configured. Further, reference numeral 25 is a toothed rod fixed to the input shaft 26 and having teeth 27 at the upper and lower edges of the inside of both arms which are bent and which are engaged with the teeth of the toothed rubber ring 8. The operation of this mechanism is exactly the same as that of the slip mechanism of the present invention, and the rotation is integrated up to a certain torque to transmit the rotation, but slips further than that.

[Effects of the Invention] As described in detail above, according to the brake mechanism of the present invention, a constant tension is applied to a brake device such as a reel shaft that brakes like when stopping the tape running. The toothed rubber ring fitted so as to be engaged with the toothed rod of the brake lever is engaged, and the braking force required for stopping is generated by the tightening force of the toothed rubber ring. It is possible to obtain the braking force, and at the same time, it is not necessary to separately provide a brake drum and the like, and it is not necessary to increase the reel diameter and the friction area to increase the braking force. Have an effect. In addition, the braking force can be set by the tension and hardness of the toothed rubber and the shape of the claws without depending on the combination of various complicated elements as in the conventional case, so that the braking force can be easily set and adjusted. .

In the above embodiment, the toothed rod of the brake lever and the toothed rubber ring have tooth-shaped teeth, and teeth are formed on the entire outer peripheral surface of the toothed rubber ring. The solenoid is always positioned so that it does not engage with the rotation of the toothed rubber ring, and the solenoid is of the suction type. However, the solenoid is not limited to this, and for example, a brake torque difference (strong / medium) is required. Without it, the toothed rod of the brake lever and the toothed shape of the toothed rubber ring may have any shape, and the teeth of the toothed rubber ring do not have to be formed on the entire outer peripheral surface, and are not on the outer peripheral surface in relation to the locking member. Alternatively, the brake lever may be used to constantly rotate the toothed rubber ring, and the same applies when the solenoid is of a type that repels when energized. Effect can be obtained.

[Brief description of drawings]

FIG. 1 shows an embodiment of a brake mechanism according to the present invention,
Fig. 3 is a plan view showing a state where the brake is not activated, Fig. 3 is a plan view showing a state where the brake is activated, Fig. 3 is a plan view showing the rubber ring with teeth, and Fig. 4 is the same as above. FIG. 5 is a side view showing a partial cross section of the mechanism, FIG. 5 is a graph showing slip characteristics when torque in the biting direction is generated, and FIG. 6 is brake torque characteristics when torque in the escape direction is generated. FIG. 7 is a perspective view showing an example in which the brake mechanism of the present invention is applied as a limiter mechanism, and FIG. 8 is a plan view showing a conventional brake mechanism operated by a cam. 1S ... Supply reel, 1T ... Take-up reel shaft, 2S ... Supply reel stand, 2T ... Take-up reel stand, 7 (7S, 7T) ...
… Brake torque generation mechanism, 8 (8S, 8T) …… Rubber ring with teeth, 9 …… Sleeve with collar, 10S, 10T …… Brake lever shaft, 11S, 11T …… Brake lever, 13S, 13T …… Spring hook , 15S, 15T …… Toothed rod, 16S, 16T …… Tension spring, 17 …… Solenoid, 18 …… Plunger, 22
……pin.

Claims (1)

[Scope of utility model registration request] 1. A brake for a rotating body having a shaft at the center to which a braking force is to be applied, a rubber which is rotatably fitted on the shaft of the rotating body and whose contact surface with the shaft is a slip surface. A brake mechanism having a ring and an engagement portion formed on the rubber ring, and further including a locking member that engages with the engagement portion and locks rotation of the rubber ring.