JPH1139977A - Contact structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact structure with which operation failure due to plastic deformation of an elastic movable part of the contact spring member is prevented and assembling work of fixed pins can easily be carried out. SOLUTION: Hook parts 22a whose tip end sides are transversely bent in relation in the direction in which they are pushed and bent against an object to be inspected are installed in the tip end parts of elastic movable parts 22 of contact spring members 2 which are helical torsion springs and are to be assembled in an insulating case 1 and restricting walls 11a set constantly face to face to the hook parts 22a are installed at positions near and in the insides of the hook parts 22a in the insulating case 1. Moreover, an engaging face (the upper end face of the slit 1b) which elastically touches the hook parts 22a and restricts the initial positions of the hook parts 22a are installed in the insulating case 1 and an engaging piece 1e which elastically touches a terminal part 23 and restricts its installation position is also installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact structure for extracting an electric signal by making a contact spring member made of a torsion coil spring resiliently contact a detection object, for example, loading a digital video cassette as a detection object. The present invention relates to a contact structure provided in a digital video recording / reproducing apparatus to sometimes take out cassette identification information or the like.

[0002]

2. Description of the Related Art A digital video recording / reproducing apparatus has a plurality (for example, four) of contact spring members formed of a torsion coil spring for extracting electric signals such as cassette identification information of a digital video cassette loaded therein. A detection contact unit configured side by side is incorporated, and by contacting the contact spring member with a metal exposed portion (contact) of the digital video cassette at the time of loading, an electric signal is output from the video cassette. It can be taken out.

In such a contact unit, a torsion coil spring having a shape indicated by reference numeral 10 in FIG. 5 is usually used as a contact spring member, and a winding part 11 of the contact unit is provided with a fixing pin (not shown). It is fixed to the insulating case 15 through the intermediary. Further, a movable portion extending from one end of the winding portion 11 is formed as an elastic movable portion 12 which is depressed and bent when it comes into contact with the digital video cassette C (the object to be detected), and projects from the other end of the winding portion 11. The short portion is a terminal portion 13 connected to an external detection circuit. Further, the contact spring member 10 has a hook portion 12a formed by bending the distal end portion of the elastic movable portion 12 into a V-shape. When the video cassette C is not loaded, the hook portion 1a is formed.
2a is elastically contacted with the upper wall 15a of the insulating case 15, and the position is regulated. Furthermore, an intermediate portion of the elastic movable portion 12 is bent into a mountain shape to form a contact portion 12b disposed on an approach path of the video cassette C. When the video cassette C is loaded, the contact portion 12b is formed. 12b
However, since it is elastically in contact with the contact provided on the bottom surface of the casing portion of the cassette C and is pushed downward in the drawing, a desired contact pressure can be obtained.

In a conventional contact unit constructed using such a contact spring member 10, four winding portions 11 are arranged in series and mounted at a predetermined position in an insulating case 15.
Assembling is performed by sandwiching and positioning and fixing each of the winding portions 11 with the fixing pin and the insulating case 15 penetrating the winding portions 11, and as a result, the elastic movable portion 12 of each contact spring member 10 is It can be elastically deformed independently. When mounting such a conventional contact unit, the terminal 13 of each contact spring member 10 is soldered to an external detection circuit while the insulating case 15 is placed on a printed circuit board (not shown). . Then, the contact unit mounted on the printed circuit board is incorporated in the digital video recording / reproducing apparatus at a position where the approach path of the video cassette C is desired. As a result, when the video cassette C is inserted into the recording / reproducing apparatus, the contact provided on the bottom surface of the cassette C comes into contact with the elastic movable portion 12 of one of the contact spring members 10 and the Of the cassette C can be extracted from the terminal portion 13 of the contact spring member 10 while pressing and bending the contact portion 12b.

[0005]

In the above-mentioned conventional contact unit, when the digital video cassette C is inserted into the recording / reproducing apparatus and the elastic movable portion 12 of the contact spring member 10 is pressed and bent, Hook part 12
a is detached from the upper wall 15a of the insulating case 15, and the elastic movable portion 12 is in a free state. Therefore, when the cassette C is removed from the recording / reproducing apparatus, an external force such as a frictional force is generated. 12 contact points 12b
May be undesirably bent and cause plastic deformation. When such plastic deformation occurs in the elastic movable portion 12, even if the video cassette C is pulled out and the elastic movable portion 12 attempts to return to the initial position by its own elasticity,
As shown by a chain line in FIG.
a, and the initial position of the contact portion 12b is extremely displaced, so that accurate detection cannot be performed by the contact spring member 10, and therefore, the reliability of the contact unit itself is significantly impaired. It will be.

When assembling this type of conventional contact unit, each contact spring member 10 is not fixed to the insulating case 15 until the fixing pin is passed through the winding portion 11, so that this fixing pin is When assembling to the insulating case 15, it is necessary to carefully work while paying attention so that the contact spring members 10 do not shift or fall off. Therefore, the assembling work of correctly positioning and fixing the plurality of contact spring members 10 to the insulating case 15 is not easy, and improvement in assemblability has been desired.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the position of the distal end portion of the elastic movable portion of the contact spring member can always be regulated by the wall surface of the insulating case. Can be prevented. Further, in the present invention, not only the elastic movable portion but also the terminal portion is elastically contacted with the insulating case, so that the contact spring member can be temporarily fixed to the insulating case before the fixing pin is incorporated, thereby improving the assembling property.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the contact structure according to the present invention, as a contact spring member for contacting and separating a contact of an object to be detected, a winding portion incorporated in an insulating case and held by a fixing pin; And a torsion coil spring having an elastic movable portion that is extended from one end thereof and is deflected when abutting on the detection object, and a terminal portion that extends from the other end of the winding portion and is connected to an external circuit. In the contact structure, at the distal end portion of the elastic movable portion, a hook portion is formed by bending a distal end sideways with respect to a direction in which the elastic movable portion is deflected, and at a location inside and near the hook portion of the insulating case, A configuration is adopted in which a regulating wall that always faces the hook portion is provided.

Such a contact structure is provided with a hook provided at the distal end of the elastic movable portion even if a strong external force acts on the elastic movable portion of the contact spring member in the buckling direction due to friction with the object to be detected. Since the position of the elastic contact portion is regulated by contacting the regulating wall of the insulating case, undesired plastic deformation is less likely to occur in the elastic movable portion, so that the elastic movable portion is less likely to malfunction.

[0010] In addition to the above configuration, a first locking portion elastically contacts the insulating case to define the initial position of the hook portion and a second locking portion elastically contacts the terminal portion to define the mounting position. With the configuration provided with the second locking portion, the contact spring member can be temporarily fixed to the insulating case before the fixing pin for holding the winding portion is incorporated.
Even when a plurality of contact spring members are incorporated in the insulating case, the assemblability is improved.

[0011]

Embodiments will be described with reference to the drawings.
FIG. 1 is a perspective view of a contact unit according to one embodiment of the present invention,
FIG. 2 is a plan view of the contact unit shown in FIG. 1, and FIG.
2 is a front view of the contact unit shown in FIG. 2, and FIG. 4 is a side view of the contact unit shown in FIGS.

The contact unit shown in these figures is provided in a digital video recording / reproducing apparatus as a memory-in switch for extracting an electric signal such as cassette identification information of a loaded digital video cassette. Such a contact unit includes an insulating case 1 which is a molded product defining an outer shape and serves as a support base for each component described later, a contact spring member 2 composed of four torsion coil springs arranged side by side in the insulating case 1, and A fixing pin 3 which penetrates the four winding portions 21 arranged in a straight line of the contact spring member 2 and collectively holds the same, and an insulating case 1 for detecting opening / closing of an erroneous erasure prevention window of a digital video cassette to be loaded. And an erroneous erasure prevention detection switch 4 incorporated in the main part.

The contact spring member 2 has a winding portion 2 fixed between the insulating case 1 and the fixing pin 3.
1, an elastic movable portion 22 which extends from one end of the winding portion 21 and is deflected when it comes into contact with the digital video cassette (the object to be detected); and an extension portion which extends from the other end of the winding portion 21 to an external circuit. A torsion coil spring having a predetermined shape and a terminal portion 23 to be connected thereto is provided. A hook portion 22a is provided at a distal end portion of the elastic movable portion 22 with a distal end side bent laterally in a direction in which the elastic movable portion 22 is deflected. . In addition, a contact portion 22b that is bent into a mountain shape and disposed on an approach path of the video cassette is provided at an intermediate portion of the elastic movable portion 22. When the video cassette is loaded, the contact portion 22b is Since the cassette is resiliently contacted with the contact provided on the bottom surface of the housing and is pushed downward in FIG. 4, a desired contact pressure can be obtained.

On the other hand, the insulating case 1 has a portion inside and near the hook portion 22a of the elastic movable portion 22,
In other words, the regulation wall 1 that always faces the hook portion 22a is provided at a location that covers the distal end side (horizontal portion) of the hook portion 22a.
a is provided. In addition, the insulating case 1 has a slit 1b through which the base end of the hook portion 22a is inserted at a location adjacent to the regulating wall 1a, and a leading end of the hook portion 22a which communicates with the slit 1b during assembly. There is provided a notch 1c used when inserted into the back side of 1a, and the upper end surface of the slit 1b is an engaging surface 1d which elastically contacts the hook portion 22a and defines its initial position. Further, a locking piece 1e is provided at the bottom of the insulating case 1 for elastically contacting the terminal portion 23 and defining its mounting position. Reference numeral 5 in the drawing is a positioning pin for positioning the loaded video cassette.

When assembling the contact spring member 2 to the insulating case 1 in the process of assembling the contact unit, first,
By inserting the hook portion 22a of the elastic movable portion 22 into the notch 1c of the insulating case 1, the base end side of the hook portion 22a is inserted into the slit 1b, and the tip end side is restricted to the regulating wall 1a.
To the back surface of. Next, the terminal portion 23 is inserted toward the vicinity of the locking piece 1 e of the insulating case 1, and the winding portion 21 is arranged at a predetermined position in the insulating case 1. At this time, the contact spring member 2 composed of a torsion coil spring is assembled into the insulating case 1 in a slightly bent state,
2a resiliently contacts the locking surface 1d of the insulating case 1 to define its initial position, and the terminal portion 23 resiliently contacts the locking piece 1e of the insulating case 1 to define its mounting position. Therefore, the contact spring member 2 can be temporarily fixed to the insulating case 1 before the fixing pin 3 for holding the winding portion 21 is assembled.

When the contact spring member 2 can be temporarily fixed to the insulating case 1 in this manner, the fixing pin 3 can be assembled while the posture of the contact spring member 2 is stabilized, so that the workability during assembly is improved. That is, if the four contact spring members 2 are temporarily fixed to the insulating case 1 in the same procedure, the fixing pins 3 are attached to the four winding portions 21 arranged in series in a stable posture.
, The contact spring member 2 can be fully fixed by simply
Since there is no need to particularly worry about the displacement or dropout of each contact spring member 2, the assemblability is greatly improved. Then, by performing the main fixing by sandwiching the winding portion 21 between the fixing pin 3 and the insulating case 1, the elastic movable portions 22 of the respective contact spring members 2 can be elastically deformed independently.

When such a contact unit is mounted, the terminal 23 of each contact spring member 2 is connected to an external detection circuit while the insulating case 1 is mounted on a printed circuit board (not shown). Solder. Then, the contact unit mounted on the printed circuit board is incorporated in the digital video recording / reproducing apparatus at a position where the approach path of the digital video cassette (the object to be detected) is desired. Thus, when the video cassette is inserted into the recording / reproducing apparatus, the contact provided on the bottom of the cassette comes into contact with and pushes the elastic movable portion 22 of one of the contact spring members 2. Since it slides with respect to the contact portion 22b while bending, various electric signals relating to the cassette can be taken out from the terminal portion 23 of the contact spring member 2.

In the contact unit described above, a strong external force in the buckling direction is applied to the elastic movable portion 22 of the contact spring member 2 by an external force such as a frictional force generated when the video cassette is removed from the recording / reproducing apparatus. The hook 2 provided at the distal end of the elastic movable portion 22
The position of the elastic movable portion 22 guided to the slit 1b of the insulating case 1 is regulated by the contact of the elastic movable portion 2a with the regulating wall 1a of the insulating case 1. There is no risk that the portion 22a will come off the regulation wall 1a. Therefore, it is extremely unlikely that the elastic movable portion 22 will cause undesired plastic deformation due to the external force. In other words, the above-described contact unit has a structure in which malfunction of the elastic movable portion 22 due to plastic deformation is unlikely to occur, such that the initial position of the contact portion 22b is greatly disturbed and detection is hindered. Is growing.

[0019]

The present invention is embodied in the form described above, and has the following effects.

Even if a strong external force acts on the elastic movable portion of the contact spring member in the buckling direction due to friction with the object to be detected or the like, the hook provided at the distal end of the elastic movable portion is restricted by the restricting wall of the insulating case. , The position of the elastic movable part is less likely to be undesirably deformed. For this reason, malfunctions due to plastic deformation of the elastic movable portion can be prevented, and reliability is improved.

Further, if the contact spring member composed of the torsion coil spring is configured to be assembled with the elastic movable portion and the terminal portion elastically in contact with the insulating case, the contact spring member can be assembled before the fixing pin is assembled. Can be temporarily fixed to the insulating case, so that even when a plurality of contact spring members are incorporated in the insulating case, the assemblability is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a contact unit according to an embodiment of the present invention.

FIG. 2 is a plan view of the contact unit shown in FIG.

FIG. 3 is a front view of the contact unit shown in FIGS.

FIG. 4 is a side view of the contact unit shown in FIGS.

FIG. 5 is an explanatory diagram showing a main part of a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 insulating case 1a regulating wall 1b slit 1c notch 1d locking surface (first locking portion) 1e locking piece (second locking portion) 2 contact spring member 3 fixing pin 4 erroneous erasure prevention detection switch 21 turns Turning part 22 elastic movable part 22a hook part 22b contact part 23 terminal part

Claims (2)

[Claims] A wound part which is incorporated in an insulating case and held by a fixing pin as a contact spring member for bringing a contact of a detected body into and out of contact with the detected body, and extending from one end of the wound part to be detected. A contact structure using a torsion coil spring having an elastic movable portion that is depressed and bent when abutting against the terminal, and a terminal portion that extends from the other end of the winding portion and is connected to an external circuit. At the tip of the part, a hook is provided with the tip side bent laterally with respect to the direction in which it is deflected,
A contact structure in which a regulating wall which is always opposed to the hook portion is provided at a position inside and near the hook portion in the insulating case. 2. The insulating case according to claim 1, wherein the first engaging portion elastically contacts the hook portion to define an initial position thereof, and the insulating case elastically contacts the terminal portion to define an attachment position thereof. A contact structure, comprising: