JPH0433574Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tape guide device that reciprocates in a guide groove while hooking a tape, and particularly relates to a tape guide device that reciprocates in a guide groove while hooking a tape. It is suitable for use with certain VTRs.

[Summary of the idea]

The present invention provides a tape guide device in which a guide member is guided through a guide groove provided on a substrate and reciprocates while hooking a tape on the tape guide. At least two protrusions for obtaining a reference surface are formed on the surface to be attached, and the guide member is provided with an opposing surface facing these, and the substrate is sandwiched between the opposing surface and the protrusions. By biasing this opposing surface toward the substrate using an elastic material provided on the substrate, the tape guide device can be positioned with high precision when forward movement is completed.

[Conventional technology]

A conventional example of a tape guide device in a tape loading device for a VTR will be described with reference to FIG.

The guide base 5, which serves as the main body of the tape guide device 4, is formed by die casting, and then a portion thereof is cut using a lathe to form a lower surface portion 5b, which serves as a reference surface. The cutting thickness obtained by the cutting process is, for example, about 0.2 to 0.3 mm. After the cutting process, the flatness of the lower surface 5b of the guide base 5 is inspected, and the upper surface 5 of the guide base 5 is inspected.
The thickness between a and the lower surface portion 5b is inspected. In the guide base 5 that has passed these inspections, holes are formed into which the tape guide 6, guide pin 7, and guide pins 8 and 9 are press-fitted, using the lower surface portion 5b as a reference surface. Thereafter, the tape guide 6 and the guide pin 7 are attached to the upper surface 5a of the guide base 5, and the lower surface 5a of the guide base 5 is attached to the guide base 5.
Guide pins 8 and 9 are attached to b. The guide pin 9 has a locking portion 9a formed at its distal end, and a distal end portion 9b at its distal end, and the guide pin 8 has a locking portion 8a formed at its distal end.

A state in which the tape guide device 4 configured as described above is attached to the drum base 1 will be schematically explained.

A drum base 1 is attached to the chassis of the VTR, and a rotary head drum (see reference numeral 17 in FIG. 2 of the embodiment) is rotatably supported on the drum base 1, and a guide groove 2 is formed near the rotating head drum and along its outer periphery. The tape guide device 4 hooks the magnetic tape 10 using the tape guide 6 and the guide pin 7, moves forward in the guide groove 2 (moves to the left in FIG. 4), and holds the magnetic tape 10 against the rotating drum at a predetermined angle. It is made so that it can be wrapped around only. The guide pin 8 of the tape guide device 4 is prevented from coming off upward in FIG.
is prevented from coming off in the upward direction in FIG. 4 by the locking portion 9a when it is inserted through the guide groove portion 2. A connecting link 14 is attached to the tip end 9b of the guide pin 9, and this connecting link 14
is biased in the _F1 direction by a loading gear (not shown) to which a locking portion 14a formed at one end is attached. The guide base 5 is rotated about the contact portion 5c as a fulcrum by this force in the _F1 direction, and the contact portion 8b hits the drum base 1 and exerts a force on the point B thereof. Further, the magnetic tape 10 is hooked on the tape guide 6 and the guide pin 7, and therefore the tape guide 6 and the guide pin 7 are hooked on.
is biased in the F2 direction. Therefore, as is clear from FIG. 4, the tape guide device 4 is subjected to a rotation biasing force in the clockwise direction. Therefore, in the tape guide device 4, the contact portion 5c of the guide base 5 is in contact with the drum base 1 at the point A, and the contact portion 8b of the locking portion 8a of the guide pin 8 is in contact with the drum base 1. By contacting the drum base 1 at two points, including point B, which is in contact with the drum base 1, its attitude and position are maintained against the rotation urging force.

When the tape guide device 4 reaches its forward movement position as described above and completes its forward movement, the magnetic tape 10 hooked on the tape guide 6 and guide pin 7 is moved to a correct and fixed position on the rotating drum. So that it is loaded in a certain posture,
The tape guide device 4 is configured.

[Problem that the invention attempts to solve]

However, since the contact portion 5c of the guide base 5 has variations in shape, the position of the point A is not constant. Further, since the abutting portion 8b of the locking portion 8a of the guide pin 8 has variations in shape, the position of the point B is not constant. Therefore, the bottom surface portion 5b of the drum base 1 and the guide base 5
The angle θ between the tape guide base 4 and the tape guide device 4 vary, and the posture and position of the guide base 4, that is, the tape guide device 4, are not constant.

The present invention provides a tape guide device for solving such problems.

[Means for solving problems]

In the present invention, a substrate is sandwiched between one surface of the guide base and an opposing surface disposed opposite to this surface of a guide member protruding from this one surface, and a substrate is provided on this substrate. In the tape guide device in which the guide member is guided by a guide groove and can be freely moved to a forward position, the tape guide device is formed of three protrusions that protrude from one surface of the guide base and are not aligned in a straight line. the guide member and the tape guide, each protruding from a reference surface, a position occupied by one of the protrusions, and a position on the other surface of the guide base corresponding to this position, with the reference surface as a reference; an elastic body that is provided on the substrate and urges the facing surface in a direction toward the substrate, and the vertical distance between the remaining two of the projections and the facing surface of the guide member is adjusted to and each of the opposing surfaces is configured to be approximately equal to the inter-plane distance of the surface in contact with the substrate, and the opposing surface is configured to be pressed against the substrate by the elastic force of the elastic body in the forward movement position. This relates to a tape guide device.

[Embodiment] An embodiment in which the present invention is applied to a tape guide device in a VTR tape loading device will be described below with reference to the drawings. Note that the same parts as in the conventional example are given the same reference numerals and their explanations will be omitted.

The procedure for forming the guide base 5, which is the main body of the tape guide device 4, will be explained with reference to FIGS. 3A and 3B.

First, the guide base 5 is formed into a block shape by die casting. At this time, this guide base 5
Protrusions 11, 12, and 13 are formed on the lower surface portion 5b so as to be arranged in a triangular shape. The three protrusions 11, 12 and 13 formed in this way
There is only one geometrically determined plane on which all the tips of the plane touch. Therefore, instead of forming the reference plane by mold-casting the guide base 5 and then cutting a part of it with a lathe as in the conventional case, the plane can be used as the reference plane X. Next, holes 18, 19, and 20 for fitting the guides 6, 7 and guide pins 8, 9 are formed with respect to the reference plane X with the same dimensional accuracy as in the prior art. Therefore, the conventional cutting process for the lower surface portion 5b can be omitted.

Next, in the guide base 5 formed as described above, the tape guide 6 and the guide pin 7 are press-fitted into the holes 19 and 20 in the upper surface portion 5a, respectively, and the guide pins 8 and 9 are press-fitted into the holes 19 and 18 in the lower surface portion 5b, respectively. The tape guide device 4 thus constructed is as follows:
Drum base 1 on which a rotating head drum 17 is provided
2 (the figure shows the tape guide device 4 in its forward position, similar to FIG. 4).
1, the drum base 1 is sandwiched between the reference surface X (FIG. 3B) formed by the projections 11, 12, and 13, and an opposing surface 8b disposed opposite the reference surface X on the guide pin 8 protruding from the lower surface 5b. At the same time, the guide pin 8 is loosely fitted into a guide groove 2 provided in the drum base 1. The drum base 11 is provided with a mounting base 1a,
A leaf spring 16 is attached to the mounting base 1a. As shown in FIG. 1, when the tape guide device 4 has completed its forward movement, the leaf spring 16 is in contact with the lower end surface 8c of the guide pin 8, and the guide pin 8
1 by the leaf spring 16. Therefore, the guide pin 8 is brought into almost perfect contact with the drum base 1 at the abutting portion 8b, which is the above-mentioned opposing surface provided on the engaging portion 8a of the guide pin 8. Also, the inclined step portion 3 is formed on the surface of the drum base 1, i.e., the surface opposite to the leaf spring 16. Therefore, the projections 12, 1 of the guide base 5 are in contact with the drum base 1.
A gap H is generated between a surface 1b of the drum base 1 against which the guide base 5 abuts and a surface 1c of the drum base 1 against which the protrusion 11 of the guide base 5 faces.

Furthermore, within the allowable range of dimensional accuracy of the tape guide device 4, the distance J between the abutment part 8b of the guide pin 8 and the reference plane X is equal to the thickness of the drum base 1 in the vicinity of the abutment part 8b. It corresponds to the sum of I and the gap H. In other words, the protrusion 12,
The vertical distance J between the projections 12 and 13 and the contact portion 8b corresponds to the distance (H+I) between the surfaces of the projections 12, 13 and the contact portion 8b that contact the drum base 1, respectively. Therefore, the guide base 5 that is lifted upward in FIG. 1 of the drum base 1 by the size of the gap H.
It is separated from c.

A connecting link 1 is attached to the tip end 9b of the guide pin 9.
4 is attached, and this connecting link 14 is urged in the F1 direction by a loading gear (not shown) to which a locking portion 14a formed at one end is attached. Further, the magnetic tape 10 is hooked on the tape guide 6 and the guide pin 7, and therefore the tape guide 6 and the guide pin 7 are
biased in the direction.

Therefore, almost the same as the conventional example shown in FIG.
The tape guide device 4 has three points: points A and C where the projections 12 and 13 are in contact with the drum base 1, and point B where the contact portion 8b of the guide pin 8 is in contact with the drum base 1. It abuts against the drum base 1 at a point to maintain its attitude and position.

In this way, since the tape guide device 4 is held at three points relative to the drum base 1, its posture and position are stable. In addition, the tape guide device 4
When the forward movement is completed, the guide pin 8 is urged upward in _FIG . Since it is biased, the guide pin 8 is in complete contact with the end of the drum base 1 and its guide groove 2. In this way, the contact portion 8b of the guide pin 8 of the tape guide device 4 is brought into complete contact with the drum base 1 and the point B is forcibly determined, so that even if the tape guide device 4 repeatedly moves back and forth, , the position of point B in its forward movement completion state is always constant, and therefore the other two
The positions of points A and C are always constant. Therefore, the tape guide device 4 can reproduce its posture and position with high restorability and high precision.

Although the present invention has been described above with reference to its embodiments, various changes and modifications can be made to the embodiments of the present invention without departing from the technical idea of the present invention. For example, in the embodiment, the drum base 1 is formed with an inclined stepped portion 3 so that the drum base 1 and the protrusion 11 of the guide base 5 do not come into contact with each other. However, the protrusion 1
If the protrusion 11 is cut after forming the hole using the only surface that contacts 1, 12, and 13 as the reference surface,
There is no need to form the inclined stepped portion 3 on the drum base 1.

[Effect of idea]

As described above, according to the present invention, after the tape guide device on which the tape is hooked completes its forward movement, the tape guide device is connected to two of the protrusions and one of the locking portions. Since the attitude and position of the tape guide device are maintained by one of the tape guide devices, the attitude and position of the tape guide device can be reproduced with high precision and high restorability.

Furthermore, if three protrusions are formed on the other surface of the guide base of the tape guide device, the reference plane of the guide base can be determined with high accuracy and high restorability using these three protrusions. . Therefore, it is no longer necessary to process a portion of the guide base using a lathe or the like to form a reference surface for forming a hole for attaching a guide member or the like to the guide base.

[Brief explanation of drawings]

The drawings show an embodiment in which the present invention is applied to a tape guide device in a tape loading device for a VTR. Figure 3A is a bottom view of the guide base, and Figure 3B is a bottom view of the guide base.
A sectional view taken along line B, FIG. 4, shows a conventional example. In the symbols used in the drawings, 1... drum base (substrate), 2... guide groove, 4... tape guide device, 5... guide base, 5a...
Top surface part (other surface), 5b... Bottom surface part (one surface), 6... Tape guide, 8... Guide pin (guide member), 8b... Contact part (opposing surface), 10
...magnetic tape, 11, 12, 13... protrusion,
16... A plate spring (elastic body).

Claims (1)

[Claims for Utility Model Registration] A board is sandwiched between one surface of the guide base and an opposing surface disposed opposite to this surface of a guide member protruding from this one surface. In the tape guide device in which the guide member is guided by a guide groove provided on the substrate and can be freely moved to a forward position, the tape guide device includes:
A reference plane formed by three protrusions that are not on a straight line, and a position occupied by one of the protrusions and a position of the other surface of the guide base corresponding to this position, respectively, with the reference plane as a reference. The guide member and the tape guide are provided in a protruding manner, and an elastic body is provided on the substrate and urges the opposing surface in a direction toward the substrate, and the remaining two of the protrusions and the guide member are provided. The perpendicular distance between the opposing surfaces of the protrusion and the opposing surface is configured to be approximately equal to the inter-planar distance between the surfaces where each of the protrusion and the opposing surface is in contact with the substrate, and in the forward movement position, the opposing surface is A tape guide device configured to be pressed onto the substrate by force.