JPH0213799Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power transmission device that intermittently transmits rotational power of a motor or the like to a driven side.

As this type of power transmission device, one for mechanical operation in a tape recorder is known. It has the configuration shown in FIG. 8, for example. Here, reference numeral 21 is a rotor driven by a DD motor, and an endless belt 23 is wound between the rotor 21 and the idler roller 22, and is connected to the flywheel 24 via this belt 23. Power is transmitted, and the rotor 21 and flywheel 24 are provided with capstans (not shown). On the other hand, the rotor 21 and the flywheel 24 each have a drive gear 25,
26 is provided, and a first
and second cam gears 27, 28 are provided. The cam gears 27 and 28 have toothless parts 27a and 28a, respectively, and the cams 29 and 30 have toothless parts 27a and 28a, respectively.
and one locking part 27b, 28b each.
The locking portions 27b and 28b are
It is adapted to be engaged with trigger levers 33 and 34 which are supported by pivots 31 and 32, respectively. The trigger levers 33, 34 are swung by the action of plungers 35, 36, and the cam gears 27, 28 have spring locking pins 27c, 28c provided on their sides. Twisted spring 3 wound around pivots 31 and 32, respectively
7 and 38, and is held resiliently in the rotational feeding direction. Return springs 39 and 40 are provided for the plungers 35 and 36, respectively. Further, cam follower levers 41 and 42 that slide on the circumferential surfaces of the cams 29 and 30 are elastically contacted with the cam surfaces by springs 43 and 44, respectively, and swing around pivot shafts 43a and 44a provided between them. I am able to move.

In such a configuration, when the plungers 35 and 36 turn on and off, the trigger lever 33 and
34 is pulled, the locking portions of the trigger levers 33, 34 and the locking portions 27b, 28b are disengaged, and the cam gears 27, 28 are sent by the elasticity of the springs 37, 38, and the drive gears 25, 26, and receives rotational force from the drive gears 25 and 26. As a result, up to the toothless parts 27a and 28a,
The cams 29, 30 are rotated, respectively, thereby
rotates and swings the cam follow levers 41, 42. Then, when the plungers 35 and 36 are turned on next time, the locking portions 27b and 28b are sent by the other locking portion of the trigger levers 33 and 34, and during this time, the torsion springs 37 and 38 are energized, and the turn-off operation is performed. Time,
The above operation is performed again.

In this case, the problem is that two triggering mechanisms (plungers) are required, and if their operating timings are different, the desired intermittent drive timing cannot be obtained, and the motor may be overloaded. I am feeling unwell because of this. Additionally, in order to switch the rotation of the motor to rotate in the opposite direction, a flywheel, belt transmission, and separate drive gears are required, which not only complicates the structure but also requires consideration of the installation space. .

The present invention has been made to improve the above-mentioned drawbacks, and has a simple structure for power transmission, in which the reciprocating motion is alternately applied to each cam gear by means of one trigger operation, and no timing deviation occurs. The aim is to provide equipment.

For this purpose, the present invention includes a drive gear that rotates by receiving power from a motor, at least one cam that can mesh with the drive gear, and at least two locking parts. first and second cam gears correspondingly having tooth-missing portions; an elasticity imparting member that urges each of the cam gears in a direction to mesh with the drive gear; and at least one of the cam gears. one or two trigger levers that can be locked in two rotational phases; during the reciprocating movement of the trigger levers between the first and second positions, one cam gear The first and second cam gears are sent to a position where they mesh with the drive gear, and the other cam gear is sent from one rotational phase to the other by the elasticity imparting member, and the operation of the trigger lever causes the first and second cam gears to move from one rotational phase to another. It is characterized in that the gears are made to mesh with the drive gear alternately.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7. In Figure 1,
Reference numeral 1 is a motor, and a drive gear 2 is provided on its output shaft. Further, corresponding to the drive gear 2, first and second cam gears 3 and 4 are pivotally supported and arranged on both sides. The cam gears 3 and 4 each include cams 3a and 4a, and
It has toothless parts 3b and 4b, and also has two rotation locking parts 3c and 3d and 4c and 4d, respectively, and further has protrusions 3e and 4e on which springs are applied, and the protrusions 3e and 4e There is a tension spring 5 between
is set up. Further, reference numerals 6 and 7 are pivot shafts that pivotally support the cam gears 3 and 4. Trigger levers 8 and 9 are provided corresponding to the cam gears 3 and 4, and the trigger levers 8 and 9 are supported by pivot shafts 10 and 11, respectively. The trigger levers 8 and 9 have locking portions 8a and 9a that engage with locking portions 3c and 3d and 4c and 4d of the cam gears 3 and 4, respectively, and have a long hole portion 8c at one end for engaging the plunger. , 9c, and the sliding core 12a of the plunger 12 has both elongated holes 8.
A pin 12b is provided that passes through c and 9c. The spring gear 12 has a return spring 1.
3 is provided, and a stopper 14 for regulating the amount of protrusion of the plunger core 12a is provided on the base side.

Further, reference numerals 15 and 16 are output levers that also serve as cam followers whose tips slide into contact with the cams 3a and 4a, and one end 15a and 16a of the output levers are connected to the cams 3a and 4a.
The intermediate portions are pivotally supported by shafts 17 and 18, and both are pulled by tension coil springs 19, respectively, and the one ends 15a and 16a are connected to the cam 3.
It is in elastic contact with a and 4a.

Next, the operation of this power transmission device is shown in Figure 2.
This will be explained sequentially with reference to FIG. When the plunger 1 is energized while the drive gear 2 is being rotated in the direction of the arrow in FIG. 2, the core 12a rises against the spring 13. As a result, the trigger levers 8 and 9 rotate, and the locking portions 8a and 9a are rotated to the locking portion 3.
c, 3d and 4c, 4d. As a result, the locking portions 3c and 4c are unlocked, so that the cam gears 3 and 4 are instantaneously moved in the direction of the arrow by the tensile force of the spring 5, and the cam gear 3 is At the rotational phase position, the cam gear 4 meshes with the drive gear 2 through its toothless portion 4b. The action of the spring 5 causes the cams 3a, 4a to pivot, thereby operating the levers 15, 16 in the directions of the arrows, respectively. At this time, the contact position between the cam 4a and the lever 16 is at the minimum radius of the cam. The cam gear 4 is thus pivoted by the drive gear 2. Next, when the plunger 12 is deenergized, the trigger levers 8 and 9 return due to the action of the spring 13, and the locking portion 8a of the trigger lever 8
and 9a are locking parts 3c, 3d and 4c, 4d
The cam gear 3, which enters the trajectory and is rotated by the tensile force of the spring 5, rotates until its locking portion 3d is locked with the locking portion 8a, and then stops at that position, that is, the second rotational phase position. However, for cam gear 4,
The lever 16 is forcibly rotated by the drive gear 2 and continues to rotate until it reaches the toothless portion 4b, so that the lever 16 moves in the direction of the arrow as shown in FIG.
The state shown in the figure is reached. Here, tension spring 5
, the cam gear 4 is rotated until the locking portion 4d is engaged with the locking portion 9a of the trigger lever 9. This position is the first rotational phase position of the cam gear 4. Next, when the plunger 12 is energized again, as shown in FIG.
Since it exits from the trajectory of 4d, the above spring 5
Each cam gear 3, 4 turns by the action of , and the cam gear 3
passes through the toothless portion 3b and becomes engaged with the drive gear, and each lever 15, 16 is moved in the direction of the arrow by the spring 5. and,
At the next moment, when the plunger 12 is deenergized, the locking portions 8a, 9a are activated, and the locking portions 3c, 3d and 4c, 4
d, and the locking portion 9a locks the locking portion 4c. This results in a state as shown in FIG. Here, the cam gear 4 is in the second rotational phase. Further, the cam gear 3 meshes with the drive gear 2 and is forcibly rotated, the lever 15 moves in the direction of the arrow, and when it comes to the toothless position, the spring 5
Due to the action of , it rotates further and comes to the state shown in FIG. 1, that is, the position of the first rotational phase.

It should be noted that when the gears 3 and 4 turn due to the spring 5, the trigger levers 8 and 9 move faster than the displacement of the respective locking portions 3c, 3d and 4c, 4d.
Since it is necessary to return a and 9a to the locking position, the plunger activation becomes extremely short.

FIG. 7 is a time chart showing the state of intermittent driving of the cam gears 3 and 4 in relation to the operation of the plunger.

In the above embodiment, in FIG. 1, the drive gear 2 outputs the output levers 15 and 16 alternately in the left and right directions, but the shape of the cam and the shape of the output levers make the outputs alternate in the up and down directions. You can do it like this. Alternatively, the vertical surface of the cam may be used to operate the output lever in a direction perpendicular to the drawing to output the output. Further, in the above embodiment, the rotation of the cam gear is converted into reciprocating motion by the output lever, but it may be alternatively output intermittently and alternately in the same direction.

Further, in the above embodiment, two trigger levers are provided and two fulcrums are provided, but two trigger levers may be provided at one fulcrum, or one trigger lever corresponding to both cam gears may be used at one fulcrum. It's okay.

Further, in the above embodiment, the trigger lever is operated by a plunger, but it may be operated by other means, such as manually.

Further, in this embodiment, the drive gear is driven by a DD motor, but it may be driven via a belt transmission system.

Further, in this embodiment, one tension spring 5 is used for imparting rotation, but it may be provided separately for each cam gear as in the conventional example.

In addition, in the above embodiment, the cam gear is provided with two locking portions and one toothless portion to obtain two types of operation modes, but three locking portions and two toothless portions are provided to obtain three types of operation modes. Of course, modifications such as obtaining the following operating modes are possible.

Such a configuration is suitable for auto-reversing equipment.
By switching between FWD and REW, and separating into pinch, head drive, and brake drive, it is very effective when applied to multi-function devices that require multiple modes (MS function, etc.).

As detailed above, the present invention allows relatively large amounts of power, such as motors, to be output alternately and intermittently in all forms by the short-time reciprocating motion of the trigger lever, and the timing can be maintained accurately. , the output in the reverse direction can be realized without intervening other means, and practical effects such as avoiding complication of the structure and requiring a small space can be obtained.

[Brief explanation of drawings]

Figure 1 is a front view showing one embodiment of the present invention;
Figures 6 to 6 are front views showing the same operating conditions, and Figure 7 is a front view showing the operating situation.
The figure is a time chart, and FIG. 8 is a front view of a conventional example. DESCRIPTION OF SYMBOLS 1... Motor, 2... Drive gear, 3, 4... Cam gear, 3a, 4a... Cam, 3b, 4b... Missing tooth part, 3c, 4c, 3d, 4d... Locking part, 3
e, 4e...Protrusion, 5...Tension spring, 6,
7... Pivot, 8, 9... Trigger lever, 8a, 9
a... Locking part, 8c, 9c... Long hole part, 10, 1
1... Pivot, 12... Plunger, 12a... Core, 12b... Pin, 13... Return spring,
14...stopper, 15,16...output lever,
5a, 16a... end, 17, 18... shaft, 19...
... Spring, 21 ... Rotor, 22 ... Idler roller, 23 ... Belt, 24 ... Flywheel, 25, 26 ... Drive gear, 27, 28 ...
Cam gear, 27a, 28a... Missing tooth portion, 27b,
28b...Locking part, 27c, 28c...Pin, 2
9,30...Cam, 31,32...Axis, 33,
34... Trigger lever, 35, 36... Plunger, 37, 38... Twisted spring, 39, 40
...Return spring, 41, 42...Cam follow lever, 43, 44...Spring, 43a,
44a...Axis.

Claims (1)

[Scope of utility model registration request] A drive gear that rotates by receiving power from a motor, etc., which is capable of meshing with the drive gear, has at least one cam, has at least two locking parts, and has a toothless part corresponding thereto. 1st
and a second cam gear, and the cam gear, respectively,
an elasticity imparting member biasing the driving gear in a meshing direction; one or two trigger levers capable of locking each cam gear in at least two rotational phases; and a free end of the trigger lever. and a plunger that outputs a trigger with a loose trigger, and during the reciprocating movement of the trigger lever between the first position and the second position, one of the cam gears is sent to a position where it meshes with the drive gear. The other cam gear is sent from one rotational phase to another by the elasticity imparting member, and the operation of the trigger lever causes the first and second cam gears to alternately mesh with the drive gear. A power transmission device characterized by: