JPH0337146Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field This invention is a tape drive device for a magnetic recording/reproducing machine.
In particular, it relates to a mechanism for switching between rewinding and fast forwarding of a tape reel.

BACKGROUND ART Conventionally, cassette tape recorders and video tape recorders that do not have endless tapes have been mainly used. Such magnetic recording and reproducing machines require tape rewinding and fast forwarding, and the reel motor is connected to the reel holder via an idler, belt, or clutch to the tape supply reel and take-up reel. I try to give it some rotation. For example, Fig. 1 shows a tape switching mechanism for rewinding and fast forwarding tape reels of a video tape recorder using this type of idler. 3 is a reel motor, and 4 is an idler. The idler 4 connects one end to the reel motor 3
The shaft 4a is loosely fitted into a bearing provided at the other end of an idler stand 5 which is rotatably pivotally mounted to a rotating shaft 3a. 6 is a compression spring stretched between the idler 4 and the shafts 4a, 3a of the reel motor 3, and the idler 4 is always attached to the reel motor shaft 3a.
The peripheral wall of the reel motor 3 is urged in the direction of pressure contact with the pulley 3b of the reel motor 3. Therefore, the idler 4 is supported on the idler stand 5 with its central axis restrained in a circular orbit around the reel motor shaft 3a, and its peripheral wall is brought into elastic contact with the pulley of the reel motor 3 by the compression spring 6. The rotation of the motor 3 rotates in the opposite direction to that of the motor. Reference numeral 7 denotes an idler guide disposed between both reel stands 1 and 2 near the idler 4, and is composed of a linear leaf spring 8 and a pair of guide poles 9 and 10 that support the leaf spring 8 at both ends. .
One end of the leaf spring 8 is movably fitted into a slit 11 provided in one of the guide poles 10, and is supported by a so-called leaf spring structure.

In the tape drive device having such a structure, when the reel motor 3 is driven to rotate clockwise as shown by the solid line arrow, the idler 4 rotates counterclockwise. At this time, the leaf spring 8 of the idler guide 7 is lightly elastically contacted with the peripheral wall of the idler 4 on the opposite side that contacts the reel motor 3, and this frictional force causes the idler 4 to move on the leaf spring 8 in the right direction as shown by the solid line arrow. Run to. Then, the take-up reel stand 2 is guided by the leaf spring 8.
abuts against the side wall of the The figure shows this abutting state. At the same time, although not shown, the brake of the take-up reel stand 2 is released by releasing a brake lever or the like, and the idler 4 contacts the take-up reel stand 2 to rotate clockwise to drive the tape to advance or feed. Conversely, when the reel motor 3 is rotated counterclockwise as shown by the dotted line arrow, the idler 4 rotates clockwise and runs on the leaf spring 8 while being guided in the left direction as shown by the dotted line arrow. It comes into contact with the side wall of table 1. Then, the tape supply reel stand 1 is rotated counterclockwise to drive the tape to rewind. In this way, the tape reel rewind and fast forward switching mechanism, which has an idler guide device between the supply reel stand and the take-up reel stand, simply changes the rotational direction of the reel motor, and the idler moves on the idler guide. The reel motor can run and provide the necessary rotation of the reel motor to the reel stand, and has the advantage of being extremely simple in structure and inexpensive to manufacture compared to mechanisms that use clutches, electromagnetic switches, etc. to switch. However, the above-mentioned conventional idler guide device supports a single leaf spring in a leaf spring structure, and therefore the leaf spring must be fixed and supported at two locations at both ends, which is particularly important for compact and miniaturized devices. It was difficult to install. In addition, it is necessary to support one end of the leaf spring so that it can move freely, but the gap between the support parts causes variations in the frictional force on the idler, making it impossible to obtain the movement torque necessary for the idler to run, resulting in insufficient rotation of the idler, etc. It had the drawback of causing mistakes. Further, in the leaf spring structure described above, a linear leaf spring is fixedly supported at both left and right ends, and the longitudinal dimension becomes large, which is an obstacle to miniaturization of the device.

DISCLOSURE OF THE INVENTION The present invention has been proposed in view of the above, and provides an idler guide device used in a tape drive of a magnetic recording/reproducing machine, which facilitates assembly and miniaturization of the device, and ensures reliable tape switching operation. It is something to do. That is, the idler guide device according to the present invention includes an arc-shaped guide portion having a curvature approximately equal to the trajectory drawn by the movement of the idler, and a leg portion having elasticity and extending from the center below the guide portion. The guide portion is arranged in light elastic contact with the peripheral wall of the idler between the supply reel stand and the take-up reel stand,
The central leg can be attached to the chassis base of the device using mounting screws or the like. Therefore, the ease of assembly is further improved compared to a conventional guide device that uses linear leaf springs and is supported at both ends. Further, since the guide portion is arcuate, a substantially uniform frictional force is obtained over the entire area where the idler moves, ensuring reliable movement of the idler and stable switching between rewinding and fast forwarding of the tape reel. Furthermore, the arcuate guide has a shorter lateral dimension than a straight guide, making the device more compact and compact.

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 2 is a front view of a tape reel rewind and fast forward switching mechanism in a tape drive device for a video tape recorder showing an embodiment of the present invention. In the figure, the basic structure and arrangement relationship of a tape supply reel stand 1, take-up reel stand 2, reel motor 3, and idler 4 are the same as in the conventional example shown in FIG. Note that the same functional parts as in FIG. 1 are indicated by the same symbols, and their explanations are omitted for the sake of brevity.

This device differs from FIG. 1 in the structure of the idler guide 12. That is, as shown in FIG. 3, this idler guide 12 includes a guide portion 13 whose contact surface with the idler 4 is formed in an arc shape with a radius of curvature that is approximately equal to the radius of curvature of the locus along which the idler 4 moves; It consists of a leg portion 14 extending from the lower center of this guide portion 13. The leg portion 14 is easily fastened to the device with a screw 16 through a mounting hole 15 provided at the lowermost end of the leg portion 14. The idler guide 12 having such a structure can be easily formed by stamping and forming an elastic bronze plate or stainless steel plate, for example, and after being attached to the device, the guide portion 13 is brought into contact with the idler 4 due to the elasticity of the leg portions 14. It acts so that an elastic force is applied in the radial direction.

Next, the rewinding and fast forwarding operations of the tape reel having such a structure are similar to the conventional example shown in FIG. It rotates, travels on the guide part 13 of the idler guide 12, and is guided to the side wall of the supply reel stand 1 or the take-up reel stand 2,
This is done by rotating each reel stand. When the idler 4 runs on the idler guide 12, a stable driving torque can be obtained due to the frictional force between the two, as described above. According to this configuration, since the guide portion 13 is formed in an arc shape, an elastic force acts in the radial direction where the idler 4 comes into contact, so that a substantially uniform frictional force can be obtained over the entire guide plate.
The idler 4 can be run reliably. In particular, in the conventional linear leaf spring 7, the contact point with the idler 4 is at the center part away from the guide poles 9, 10 at both ends, and the elastic force is relatively weakened. Although it is difficult to obtain operating torque and switching errors are likely to occur, this configuration eliminates such switching errors. Furthermore, since the idler guide 12 can be attached to the device by simply screwing the central leg portion 14 at one point, the assembly work is simplified. Further, since the guide portion 13 is formed in an arc shape, there is no need to unnecessarily increase the lateral dimension by attaching the idler guide, and various effects such as miniaturization of the device can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a front view of a tape switching mechanism for rewinding and fast forwarding of a conventional video tape recorder, and FIG. 2 is a front view of a tape switching mechanism for rewinding and fast forwarding of a video tape recorder according to an embodiment of the present invention. FIG. 3 is an enlarged perspective view of the main part of FIG. 2. 1... Supply reel stand, 2... Take-up reel stand,
3... Reel motor, 4... Idler, 5... Idler stand, 12... Idler guide.

Claims (1)

[Claim for Utility Model Registration] A supply reel stand for supplying tape, a take-up reel stand for winding the tape, a reel motor for driving these reel stands, and one end rotatably supported. an idler stand disposed at the other end of the idler stand and configured to transmit and drive the rotational force from the reel motor to the supply reel stand or the take-up reel stand; and an idler guide extending between the supply reel stand and the take-up reel stand and guiding the idler to move between the supply reel stand and the take-up reel stand by rotational force from a reel motor. , A magnetic recording and reproducing machine, characterized in that the idler guide has a surface in elastic contact with the idler formed in an arc shape with a curvature approximately equal to a curvature of a locus along which the idler is moved by the rotational force from the reel motor. tape drive.