JPH0668856B2 - Pinch roller drive mechanism - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pinch roller drive mechanism, and more particularly to a pinch roller drive mechanism for a VTR having a traveling system outside a capstan.

The tape path of the magnetic tape at the time of recording / reproducing of a normal home VTR is, for example, as shown in FIG. 8, wound around the rotary head 4 from the supply reel via the impedance roller 2, the full width erasing head 3, etc. It has a path in which the capstan 6 and the pinch roller 7 hold it via 5 and it is taken up by the take-up reel 8. Also,
In a normal VTR, a capstan 6 is provided inside the tape path and a pinch roller 7 is provided outside the tape path in order to simplify the mechanical section, and the magnetic tape is connected to the capstan 6 by the planar movement of the pinch roller 7. It was configured to be able to be held by the pinch roller 7.

However, in the structure in which the capstan 6 is provided on the inner side and the pinch roller 7 is provided on the outer side with respect to the tape path as shown in FIG. Although the tape path with the reel 8 needs to be long, the capstan 6 needs to be provided near the take-up reel 8 in order to load the magnetic tape, and the tape path with the take-up reel 8 becomes short. As a result, stable tape running cannot be obtained.
Further, since the capstan 6 needs to be provided at a position to be inserted into the loading hole of the tape cassette, the upper space is limited, and as shown in FIG.
It is necessary to make the shaft bearing 6a supported by the ball bearings 6b and 6c at the two lower positions, and the capstan becomes large in the lower part of the tape, so the mechanism becomes large.

Therefore, it is necessary to provide the capstan 6 outside the tape path and the pinch roller 7 inside the tape path as shown in FIG.
It is necessary to provide a pinch roller drive mechanism that allows the tape to escape upward so as not to get in the way of the tape.

2. Description of the Related Art FIG. 6 shows a perspective view of a conventional pinch roller driving mechanism.
In the figure, 9 is a pinch roller, 10 is a pinch roller arm, 11
Is an up-down lever, and 12 is an up-down cam.

In the conventional pinch roller driving mechanism, as shown in FIG. 6, a driving force from a motor (not shown) is transmitted to the main gear 13, and the first cam gear 14 and the second cam gear 14 meshed with the main gear 13 are engaged.
Is transmitted to the cam gear 15. The first cam gear drives a loading gear (not shown) and also drives the half loading arm 42 to hold the tape in a loaded or half loaded state.

The second cam gear 15 drives the control plate that controls the other mechanical parts by the cam portion 15a, and also drives the relay gear 16 meshed with the gear portion 15b. The relay gear 16 coaxially has a first gear portion 16a and a second gear portion 16b, and the first gear portion 16a is the gear portion 15b of the second cam gear 15.
The second gear portion 16b meshes with the gear portion 12a of the up / down cam 12 to transmit the driving force from the second cam gear 15 to the up / down cam 12.

The up-down cam 12 has a spiral groove 12b along the shaft 17.
Is provided. The protrusion portion 11a of the up / down lever 11 provided on the shaft 17 so as to be vertically movable is engaged with the groove portion 12b. A press lever 19 and a pinch roller arm 10 to which a pinch roller 9 is attached are laminated on an upper part of the up / down lever 11 so as to be vertically movable on a shaft 18. Therefore, as the up / down cam 12 rotates, the up / down lever 11 moves up and down along the shaft 17, so that the pinch roller 9 also moves up and down.

The up / down cam 12 is provided with a cam portion 12c, and the shaft 1
The arm portion 20a of the arm gear 20 rotatably fixed to 7 is pressed to rotate the arm gear 20. A guide arm 21 provided with a guide pole 21a on the gear 20b of the arm gear 20.
The gear portion 21b is meshed and the guide pole 21a is moved according to the rotation of the up / down cam 12.

The up / down lever 11 is rotated by the rotation of the up / down cam 12.
Is lowered to the lowest position, press lever 19
Comes into contact with the protrusion 12d of the up / down cam 12 and rotates about the shaft 17, and the pin 11b of the up / down lever 11
Engages with the guide arm 21 to position the guide pole 21a. The press lever 19 is engaged with the pinch roller arm 10, and the rotation of the press lever 19 causes the pinch roller arm 10 to rotate in the direction of crimping a capstan (not shown) so that the tape can run. It was configured as.

However, the conventional pinch roller drive mechanism requires two high shafts, a pinch roller arm, a press lever and an up / down lever shaft, and an up / down cam shaft, and requires a large space. In addition, since a large number of shaft levers and gears are required, the cost is high, and the parts are arranged above and below the main deck, which causes a problem that assembly is troublesome and productivity is deteriorated.

The present invention has been made in view of the above points, and an object of the present invention is to provide a pinch roller drive mechanism that has a small number of parts and can be configured in a small space.

Means for Solving the Problems The present invention provides a main cam gear having a main gear for transmitting a driving force and a cam groove, and a pole moving means for moving a pole that meshes with the main cam gear and forms a tape path near a capstan. A pinch roller cam having a gear portion that meshes with the main cam gear and that rotates according to the rotation of the main cam gear, and a groove portion that is provided spirally around the rotation axis of the gear portion and that rotates together with the gear portion; Is engaged with the groove portion of the pinch roller cam, moves in the rotation axis direction as the pinch roller cam rotates, and engages with the cam groove of the main cam gear at the time when the limit point of movement is reached. And a pinch roller unit that presses the pinch roller to the capstan by rotating the main cam gear about a rotation shaft. Become.

Action When the main cam gear rotates, the pole moving means that meshes with the main cam gear drives to move the pole to form a tape path, and at the same time rotate the pinch roller cam to move the pinch roller unit in the rotation axis direction of the pinch roller cam. To do.

When this movement causes the pinch roller unit to reach the limit point of movement, the pinch roller unit engages with the cam groove of the main cam gear, and when the main cam gear further rotates, the pinch roller unit rotates about the rotation axis of the pinch roller cam and moves to the capstan. Crimp on.

Conventionally, since the pinch roller cam vertically moves the pinch roller unit and presses the pinch roller to the capstan, the pinch roller cam and the pinch roller unit have different axes, but according to the present invention, as described above, By engaging the pinch roller unit with the cam groove of the main cam gear and rotating the pinch roller unit, the pinch roller unit and the pinch roller cam are pressed against each other by pressing the pinch roller unit to the capstan so that the axes of the pinch roller unit and the pinch roller cam are the same. be able to.

Embodiment FIG. 1 shows a schematic perspective view of an embodiment of the present invention. In the figure
22 is a pinch roller, 23 is a pinch roller arm, 24 is a press lever, and 25 is a pinch roller cam.

The main cam gear 26 includes a first gear portion 26a and a second gear portion 26b.
And the cam groove 26c, and the driving force from the motor 33 is transmitted by the worm gear 37 (see FIGS. 2 to 4). The first gear portion 26a of the main cam gear 26 is the pinch roller cam 2
The pinch roller cam 25 is rotated by meshing with the gear portion 25a of 5. Further, the first gear portion 26a meshes with the half loading gear 27 which is a pole moving means to rotate the half loading arm 29 in which the half loading pole 28 is planted. Guide pole for half loading gear 27
Like the half loading gear 27 in which 30a is planted, the guide arm 30 is engaged with the half loading gear 27 because the gear portion 30b of the guide arm 30 that is the pole moving means is meshed.
It rotates with the rotation of.

As shown in FIG. 1B, the first gear portion 26a of the main cam gear 26 and the half loading gear 27 that meshes with the first gear portion 26a.
Is an intermittent gear, and is configured so that the half loading pole 28 and the guide pole 30a stop at predetermined positions.

The press lever 24 is attached to the pinch roller cam 25 from above so that the claw portion 24a provided inside the press lever 24 and the groove portion 25b spirally provided on the pinch roller cam 25 along the shaft 31 mesh with each other. . A claw portion 24d is provided on the outer side of the rear portion of the press lever 24. A rail that extends and that serves as a rotation guide groove that allows the press lever 24 to rotate.
It engages with the guide groove of 39 (refer to FIGS. 2 to 3).

A pinch roller arm 23 provided with a pinch roller 22 is locked to the press lever 24 by a claw portion 24b and a spring 32. In addition, the press lever 24 has a press lever
Main cam gear when 24 descends to bottom along axis 31
A pin 24c to be inserted into a cam groove 26c provided in 26 is provided.

Next, the operation of this embodiment will be described with reference to FIG. 2, FIG. 3, and FIG.

FIG. 2 shows a state before the tape is loaded. The pinch roller 22 is located above the shaft 31, and the half loading pole 28 and the guide pole 30a are also loaded with the loading poles of the tape cassette. It is located below the hole.

When the tape cassette is inserted, the motor 33 rotates. The driving force of the motor 33 is the pulleys 34, 35 and the belt 36.
Is transmitted to the worm gear 37 via. Worm gear 37
The main cam gear 26 meshes with the main cam gear.
26 starts spinning.

When the main cam gear 26 rotates, the half loading gear 27 meshing with the main cam gear 26 rotates and the half loading pole 28 moves, and the guide pole 30a moves as the half loading gear 27 rotates. Then, the half loading operation is completed when the intermittent portion of the half loading gear 27 is raised to the bank portion of the main cam gear 26. FIG. 3 shows the state of the apparatus during half loading. In this state, since the lead of the spiral groove 25b above the pinch roller cam 25 of the press lever 24 is cut small, the pinch roller 22 slightly descends downward. Therefore, the pinch roller 22 does not interfere with the formation of the tape path during half loading.

Next, when shifting from the half loading state to the normal loading state, by further rotating the main cam gear 26, the press lever 24 moves in the groove portion 25b having the lead of the pinch roller cam 25,
It descends greatly. At this time, the press lever 24 should not rotate together with the pinch roller cam 25
The claw portion 24d of the press lever 24 is engaged with 39. When the press lever 24 descends to the lowest position, the pin 24c of the press lever 24 is inserted into the cam groove 26c of the main cam gear 26 and moves along the cam groove 26c. Since the pin 24c is pressed outward from the center of the main cam gear 26 during the movement, the press lever 24 slightly rotates. Because of this, the press lever
The pinch roller arm 23 locked to 24 also rotates, and the pinch roller 22 is pressed against the capstan 38. A rail is cut at the bottom of the rail 39 so as not to interfere with the rotation of the press lever 24. This state is shown in FIG. This completes normal loading.

In addition, as shown in the present embodiment, the capstan 38 is provided outside the tape path, so that the capstan shaft is
Since there is no restriction on the space above 38, for example, as shown in FIG.
Can be provided above and below and can be easily configured to endure the pressure force from the pinch roller as shown by arrow A. Therefore, the bearings 40 and 41 can be composed of oil-less metal or oil-impregnated bearings that are less expensive than ball bearings.

As described above, according to the present invention, by providing the main cam gear, the pinch roller unit and the pinch roller cam can have the same shaft, and the number of shafts can be reduced, so that the mechanism can be simplified, The number of parts is smaller than that of the conventional one (for example, the number of parts of the conventional one shown in FIG. 6 is 27 for shaft 11 (large 2), sheet metal 1, molded product 10, pinch roller 1, spring 4). On the other hand, in the first embodiment, the shaft 7 (large 1), the sheet metal 1, the molded product 5, the pinch roller 1, and the spring 3 can be used for 17 points.) Therefore, the reliability of the mechanism can be improved. Improvement and cost reduction,
In addition, it can be constructed in a space-saving manner, and since the parts can be provided only on the upper surface of the main deck, the productivity can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an embodiment of the present invention, FIGS. 2 to 4 are views for explaining the operation, and FIG. 5 is a capstan of an embodiment of the present invention. 6 is a perspective view of an example of a conventional capstan, FIG. 7 is a sectional view of an example of a conventional capstan, and FIG.
The figure is for explaining the tape path of a normal VTR, 9th
The figure is a diagram for explaining the tape path of the VTR of the traveling system outside the capstan. 22 …… Pinch roller, 23 …… Pinch roller arm, 24…
… Press lever, 25 …… Pinch roller cam, 26 …… Main cam gear, 28 …… Half loading pole, 30a…
… Guide pole.

Claims (1)

[Claims] 1. A main cam gear having a main gear for transmitting a driving force and a cam groove, a pole moving means for meshing with the main cam gear, for moving a pole forming a tape path near a capstan, and the main cam gear. A pinch roller cam that meshes with the main cam gear and that rotates according to the rotation of the main cam gear, and a groove portion that is provided spirally around the rotation axis of the gear portion and that rotates with the gear portion; And engages with the groove portion of the pinch roller cam, moves in the rotation axis direction with the rotation of the pinch roller cam, and when the limit point of the movement is reached, the main cam gear And a pitch roller unit that engages with the cam groove and rotates about the rotation shaft by rotation of the main cam gear to press the pinch roller against the capstan. Pinch roller drive mechanism that.