JPH0210600Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a bidirectional rotation transmission mechanism that is provided between a pair of reel stands and rotates the reel stands.

Conventional mechanisms for winding tape in both fast-forward and fast-reverse directions include a pulley directly connected to a motor and an idler pulley with a slip mechanism that can be freely pressed against a take-up reel stand and a rewind reel stand using compression springs. The above-mentioned pulley is rotated by the forward and reverse rotation of the motor, and the idler pulley that is in pressure contact with the pulley is oscillated and reversed by the forward and reverse rotation of the pulley, and is brought into contact with the take-up reel stand or the unwind reel stand, and the crimping force and biting force It has a structure that transmits the rotational force from the motor to both reel stands.

In order to smoothly and reliably rotate the pulley without slipping between the pulley and the idler pulley, the relationship between the rotational torque and the compression spring is an important point.When the rotational torque is small and the compression spring force is large, On the other hand, if the rotational torque is large and the compression spring force is small, slippage and vibration of the idler pulley will occur due to insufficient transmission force. For this reason, standard values are set and managed for rotational torque and compression spring force, but there is a drawback that management is troublesome.

In addition, due to the recent trend toward power saving, it is necessary to suppress mechanical loss as much as possible, and it is not desirable to increase the rotational torque and spring force unnecessarily, as the mutual relationship will not go well, and if the rotational torque is increased, the crimping force will also increase accordingly. There are drawbacks that must be met.

In view of the above-mentioned drawbacks, the purpose of the present invention is to propose a bidirectional rotation transmission mechanism in which the relationship between rotational torque and crimping force is made somewhat rough, and in which the idler pulley reliably performs swing reversal even if the relationship is made rough. There is a particular thing.

The present invention is characterized by: a drive wheel in which a gear rotated by a motor and a pulley are coaxially formed; an idler pulley that can be pressed into contact with the pulley of the drive wheel;
an idler lever that rotatably supports the idler pulley; and an idler lever that frictionally engages with the idler pulley and is rotatably supported by the idler lever, whose rotational range is restricted by the idler lever, and that is connected to the gear. a reversing lever in which meshable arc-shaped teeth are formed; a spring that biases the idler lever in the direction of the drive wheel; a support means that supports the idler lever in a biasing direction and swingable; and the idler lever. a driven wheel that faces both sides of a displacement range of the idler pulley due to the swinging of the idler pulley, and to which rotation of the pulley is transmitted via the idler pulley; The width is such that the meshing with the gear ends before it is rotationally driven by the pulley via an idler pulley,
The idler pulley is configured not to come into pressure contact with the pulley when the gear is in a position where the arcuate teeth formed on the reversing lever and the gear engage.

The present invention will be explained below with reference to illustrated embodiments. 1st
In the bidirectional rotation transmission mechanism shown in FIGS. 1 and 2, an output shaft 20 of a motor (not shown) is protruded from the upper surface of a chassis 1, and a drive wheel 2 is fixed thereto, and a gear 21 and a pulley 22 are formed on the drive wheel. Arc-shaped teeth 32 formed at the tip of a fan-shaped protrusion 31 of the reversing lever 3 are disposed on the gear 21 so as to be able to mesh with each other, and the lower end of the reversing lever 3 is press-fitted into the idler lever 4 with a spacer ring 5 sandwiched between the lower surfaces. It is fitted onto the shaft 41. An idler pulley 42 is fitted onto a shaft 41 on the top surface of the reversing lever 3 with a felt 6 in between, and a loosely fitted spring washer 4 is fitted onto the shaft 41 on the top surface of the idler pulley.
3. Fixed spring washer 4 into which coil spring 44 is fitted
5 is fitted and fixed to the shaft, the idler pulley is urged downward, and a rubber tire 46 is fitted to the outer periphery of the idler pulley 42, and the drive wheel pulley 22
He is being forced to press freely.

The idler lever 4 is placed on the chassis 1, has an arm 4b protruding from one side of a disc 4a, and has a pin 4c provided on the lower surface of the arm that extends in the direction of the driving wheels 2, which is bored in the chassis 1. The idler lever 4 is pushed into the elongated hole 11, and a spring 7 is applied to the pin 4c, so that the idler lever 4 is biased toward the driving wheels. Both ends of the spring 7 are horizontally elongated holes 12 and 1 bored in the chassis 1.
2 is bent and inserted. A pair of retaining arms 4e, 4e are provided on the lower surface of the idler lever 4, and a long hole 1 in the shape of an inverted V is bored in the chassis 1.
3 and 13, it is brought into contact with the back surface of the chassis. A driven wheel 8 for the take-up reel stand and a driven wheel 9 for the unwind reel stand are arranged on both sides of the idler pulley 42, respectively.

The width of the arcuate teeth 32 of the reversing lever 3 is formed so that the engagement with the gear 21 ends during the swinging of the idler lever 4. Arc-shaped tooth 3
Stoppers 47 and 48 are provided on the upper surface of the idler lever 4 with a slight gap on both sides of the fan-shaped protrusion 31 on which the idler lever 2 is provided. The felt 6 provided on the upper surface of the reversing lever 3 is formed into a ring shape and is adhesively fixed to the upper surface. The pulley 22 of the driving wheel 2 is not in contact with the rubber tire 46 of the idler pulley 42 in the state shown in FIGS. 1 and 2. Further, the stoppers 47 and 48 may have other shapes at other positions as long as the reversing lever is supported by the idler lever in a regular rotation range.

With the bidirectional rotation transmission mechanism configured as described above, when the drive wheel 2 is rotated in the clockwise direction A in FIG. When the fan-shaped protrusion 31 hits the stopper 47, the idler lever 4 starts to swing counterclockwise about the pin 4c. When the idler lever 4 is swung and the arc-shaped teeth 32 are disengaged from the gear 21, the idler pulley 42 is pushed together with the idler lever 4 by the spring 7 and is moved forward in the direction of the driving wheel 2, and the rubber tire 46 is moved toward the pulley 22. The idler pulley 42 is rotated in the counterclockwise direction A'', and the swinging of the idler lever 4 further progresses to bring the rubber tire 46 into pressure contact with the driven wheel 8 as shown in FIG. The rotation is transmitted to the driven wheel 8 in the clockwise direction.At this time, the reversing lever 3 is urged to rotate counterclockwise by the idler pulley and the felt 6.

When returning the idler pulley 42 to the one shown in Figure 1,
When the motor is reversed, the idler pulley is rotated clockwise by the pulley 22 of the driving wheel 2 on the idler lever 4 that has stopped at the transmission position, and the reversing lever 3 is rotated clockwise by the friction of the felt 6. The fan-shaped protrusion 31 is the stopper 48
When the idler lever 4 rotates until it hits the stopper, the arc-shaped tooth 32 meshes with the gear 21 of the drive wheel 2 and the idler lever 4 rotates in the opposite direction. swayed,
Further, as the motor continues to rotate, the idler lever 4 is swung in the same manner as when the idler pulley 42 is pressed against the driven wheel 9, in the same manner as when the idler pulley 42 is pressed against the driven wheel 8. In order to switch the engagement between the arcuate tooth 31 and the gear of the drive wheel at the swing end to sliding contact between the idler pulley 42 and the pulley 22, the angle of the arcuate tooth is formed to a width that allows it to come off from the gear 21 at the swing end. There is. Furthermore, when the arc-shaped teeth 32 and the gear 21 are in mesh, the rubber tire 46 of the idler pulley 42 and the pulley 2
2 does not hit, which prevents the rubber tires from deforming.

When the idler pulley 42 is returned from the state in which it is pressed against the driven wheel 8 or 9 to the state shown in FIG. 1, the drive wheel 2 is controlled to rotate counterclockwise or clockwise by a control circuit and a position detection device (not shown). .

Since the present invention is constructed as described above, the gear of the drive wheel rotated by the motor and the arcuate teeth of the reversing lever mesh with each other, and a large rotational torque due to the driving force of the motor acts on the reversing lever, causing the idler pulley to swing. Inversion can be performed reliably without slipping. Also, when the reversing lever is reversed, the friction torque caused by the felt acts on the reversing lever as a rotational torque, and this rotational torque is a small torque necessary for the reversing lever to swing and the arcuate teeth to mesh with the gears. Therefore, the friction torque caused by the felt can be kept small. In addition, this friction torque is a power loss that also occurs when the idler pulley swings and reverses and when the driven wheel is driven to rotate.As mentioned above, the friction torque can be kept small, resulting in equipment savings. Can be electrified. Furthermore, while achieving power savings through small frictional torque, large rotational torque is obtained from the driving force of the motor when the idler pulley swings, so there is no need to manage the rotational torque in accordance with the compression force of the spring.
Even if the relationship between the rotational torque and the compression force of the spring is configured to be somewhat rough, the swinging reversal of the idler pulley can be reliably performed. Furthermore, when the reversing lever is located at the position where the arc-shaped teeth and the gear mesh, the rubber tire of the idler pulley is not pressed against the pulley or the driven wheel, which causes problems such as deformation and fusion of the rubber tire that may occur if left for a long time. It is possible to provide a bidirectional rotation transmission mechanism that has excellent practical effects such as solving the problem.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is an explanatory diagram of a state in which the idler pulley of the bidirectional rotation transmission mechanism is not rotated, Fig. 2 is a cross-sectional side view taken along the line of Fig. 1, and Fig. 3 is an illustration of the idler pulley in a bidirectional rotation transmission mechanism. It is an explanatory view of a state in which the pulley is swung to the right. 2... Drive wheel, 21... Gear, 22... Pulley, 3... Reversing lever, 32... Arc tooth, 4...
... Idler lever, 41 ... Shaft, 42 ... Pulley frictionally connected to the reversing lever (idler pulley), 7 ... Spring, 8, 9 ... Driven wheel.

Claims (1)

[Scope of utility model registration request] A drive wheel in which a gear rotated by a motor and a pulley are coaxially formed, an idler pulley that can be pressed into contact with the pulley of the drive wheel, an idler lever that rotatably supports the idler pulley, and friction with the idler pulley. a reversing lever that engages with the idler lever, is rotatably supported by the idler lever, has a rotation range regulated by the idler lever, and has protruding arcuate teeth that can mesh with the gear; and the idler lever. a spring that biases the idler lever in the direction of the drive wheel; a support means that supports the idler lever in the biasing direction and in a swingable manner; a driven wheel whose rotation is transmitted via the idler pulley, and the arcuate tooth formed protrudingly on the reversing lever is configured to rotate the driven wheel before the driven wheel is rotationally driven by the pulley via the idler pulley. is configured such that the idler pulley does not come into pressure contact with the pulley of the drive wheel when the gear is in a position where the arcuate teeth protrudingly formed on the reversing lever are in mesh with the gear. Bidirectional rotation transmission mechanism.