JPS6142765A - Pinch roller pressure contact mechanism of magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To realize always stable tape running by providing a notch bringing a pinch roller press contact onto a capstan shaft and giving a step to one side ridge of the notch so as to minimize the amount of change in the pinch press. CONSTITUTION:The main lever 1 has a notch 20' pressing the pinch roller 4 onto the capstan shaft 9. One side ridge 20a' of the notch 20' has a step S. In this case, when the notch 20' is displaced from the recording/reproducing position to the winding/reproducing position, since the moving pin 12 moves from the lower side to the upper side of the step S, the absolute position of the moving pin 12 is changed not so much and the amount of change in the pinch pressure is minimized. Thus, the tape running always stable is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a pinch roller pressure welding machine tank for magnetic recording/reproducing devices such as VTRs and tape recorders.

The structure of the conventional example and its problems In a magnetic recording/reproducing apparatus such as a VTR, the present inventor has devised a mechanism for pulling out the tape from the cassette by a pinch roller and pressing the pinch roller against the capstan shaft by a machine [61]. This mechanism has been proposed extensively, but first, this mechanism will be explained based on FIGS. 3 and 4.

In Figure 3, (1) is the main lever, and the arrow (at
Can move linearly in the force direction. (2) is a pinch roller arm that is rotatably attached to the fixed shaft (3) and rotatably supports the pinch roller (4), and this pinch roller arm (2) is attached to the main lever (1). The main lever (1) can be rotated freely around the engaging pin (5) and fixed shaft (6).
(in response to the movement in the a1 direction, the pinch roller (4) is rotated in a known manner to bring the pinch roller (4) together with the tape (8) pulled out from the cassette (not shown) near the capstan shaft (9) The pinch roller arm (2) is rotatably connected to one end of the first link (6) via a connecting pin αO, and the other end of the first link 0 is connected via a moving pin @. It is rotatably connected to one end of the second link (to).The other end of the second link (to) is connected to the connecting pin α4
It is rotatably connected to the intermediate part of the press-contacting lever (to) via. One end of the pressure welding lever (to) is fixed shaft q1
The other end is rotatably supported by a guide slot αη.
is formed. A fixed regulation pin (to) is loosely fitted into this guide slot (b). In addition, press lever αG
At the other end is a spring α that applies a biasing force in the direction of arrow (b).
9 is connected (one end of the spring is connected to a fixing member not shown).

Further, the main lever (1) is provided with a rectangular notch (1), and one side edge (20a) of this notch can be engaged with the moving pin α4.

In the above configuration, the pinch roller (4) and the tape (
Immediately after the main lever (8) is brought into the vicinity of the capstan shaft (9), one side edge (20a) of the notch formed in the main lever (1) is in a state in which it is just in contact with the moving pin. In this state, when the main lever (1) is moved in the direction of the arrow fa), the movable pin (2) that is in contact with the - side edge (20a) of the notch (A) also moves in the same way, and both links (B) are moved. (to) expands, and as a result, the pinch roller arm (2) rotates slightly in the direction of the capstan shaft (9), and the pinch roller (4) comes into contact with the capstan shaft (9). While the pinch roller arm (2) can rotate, the pressing lever (to), which is pulled by the spring α, does not rotate, and therefore the position of the connecting pin (to) remains constant. However, after the pinch roller (4) contacts the capstan shaft (9), further movement of the main lever (1) in the direction of arrow (a) causes the moving pin @ to move and both links (7) Even if it is expanded, the pinch roller arm (2) can no longer rotate, so both links (11)
) The expansion of C13 is absorbed by the rotation of the pressing lever α9 in the direction of arrow (d) against the biasing force in the direction of (b) near the spring α. As a result, the biasing force of the stretched spring uo is transmitted via the pressure contact lever (to), the two shafts αj, and the pinch roller arm (2), and the pinch roller (4) is pressed against the capstan shaft. (9) and can generate the required tape driving force.

However, in general, when rewinding and playing back, the tension band must be released to lighten the load on the supply reel stand, so the main reno (-(1)) is moved to the tension post or tension band position. Therefore, the position of the main reno (-(1)) is different during recording and playback and during rewind playback, and as a result, in the above mechanism, as shown in FIG. There will be a large shift from the position shown by the virtual line to the position at the time of rewinding playback.This will result in a large difference in the amount of extension of the spring (1'l).
The pinch pressure differs greatly between recording and playback and rewinding playback, which can cause tape slippage or, conversely, cause too much load to be applied to the capstan shaft (9), causing deformation.

Purpose of Screaming The present invention solves the above-mentioned problems, and provides a pinch roller pressure contact mechanism for a magnetic recording/reproducing device in which the pinch pressure does not fluctuate much during recording/reproducing and rewinding/reproducing. The purpose is to

Structure of the Invention In order to achieve the above object, the pinch roller pressure contact mechanism of the magnetic recording/reproducing apparatus according to the present invention includes a rotatable pinch roller arm to which a pinch roller is attached to rotate freely five times;
a main lever that is linearly movable; a first link that is rotatably connected to the pinch roller arm; a second link that is rotatably connected to the first link via a movable pin; and a spring that biases the pinch roller in the direction of pressing the pinch roller against the capstan shaft via both links, the main lever is connected in one direction σ. By moving in a straight line, the moving pin is engaged and moved at one side edge, and both links are expanded.
It has a notch that presses the pinch roller against the capstan shaft, and one side edge of this notch has a step, and when the notch is in the recording/playback position, the movable pin moves under the step. The position of the stepped portion is set so that the movable pin is located above the stepped portion when the notch/hole is in the position for rewinding and playback.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. It should be noted that since the present invention is based on the mechanism shown in FIG. 8, only the parts that are different from this will be explained here, and the explanation of other parts will be omitted.

In Figures 1 and 2, the main lever (1) (3rd
(see figure) has a notch (a)′, and this notch (
1)' has a step (S) at one side edge (20'a). When the pinch roller is in pressure contact with the capstan shaft, the position of the connecting pin αO does not change.

The moving pin @ moves along an arcuate path centered on the connecting pin αO. Therefore, it is preferable that the stepped portion (S) is along an arc of radius (r) of the movable pin @ centered at the position h1 from the notch (to) sieve surface that the movable pin @ occupies during recording and reproduction.

In the above configuration, when the second cause of the notch (1)'75 is displaced from the recording/reproducing position indicated by the solid line to the rewinding/reproducing position indicated by the imaginary line, the moving pin @ moves from the bottom of the stepped portion (S). Since it moves upward, the absolute position of the moving pin @ does not change much, and the amount of change in pinch pressure can be suppressed to a minimum.

On the right, the position and shape of the stepped portion (S) are not limited to those shown in the drawings, and the movable pin (2) does not move toward the stepped portion (S) during recording and reproduction.
It is sufficient to set it so that it is located below the stepped portion (S) and above the stepped portion (S) during rewinding.

As described in the following section, in the pinch roller pressure contact mechanism of the magnetic recording and reproducing apparatus of the present invention, during recording and reproducing, the movable pin is located below the step provided on one side edge of the notch, and the winding Since the moving pin is positioned above the stepped portion during return playback, the amount of change in pinch pressure in both operation modes can be minimized and stable tape running can be realized at all times.

[Brief explanation of drawings]

FIG. 1 is a plan view showing essential parts in an embodiment of the present invention;
Fig. 2 is a plan view showing the operating principle of the same embodiment, Fig. 3 is a schematic plan view showing the pinch roller pressure welding machine groove of the magnetic recording/reproducing device which is the basis of the present invention, and Fig. 4 is a schematic plan view showing the principle of operation of the same machine. FIG. Ll)...Main lever, (2)...Pinch roller arm, (4)...Pinch roller, (9)...Capstan shaft, (l])...First link, @ ...Moving pin, t13...@2 link, α9... Pressing lever, Ql... Spring,...'... Notch, (2σa
)...One side edge of the notch, tS)...Danbe agent
Yoshihiro Morimoto Figure 1 ψ′

Claims (1)

[Claims] 1. A rotatable pinch roller arm to which a pinch roller is rotatably attached, a linearly movable main lever, a first link rotatably connected to the pinch roller arm, and this first link. A second link rotatably connected via a moving pin, a rotatable pressing lever rotatably connected to the second link, and a pinch roller via the pressing lever and both links. and a spring biased in the direction of pressure contact with the capstan shaft, and the main lever moves linearly in one direction to engage and move the movable pin at one side edge to spread both links and tighten the main lever. It has a notch that presses the pinch roller against the capstan shaft, one edge of this notch has a step, and when the notch is in the recording/reproducing position, the movable pin is located below the step. A pinch roller pressure contact mechanism for a magnetic recording/reproducing device, wherein the position of the stepped portion is set so that the movable pin is located above the stepped portion when the notch is at the rewinding and reproducing position.