JPH0213982Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a stylus device for a checker used for checking unit assemblies and printed boards provided on printed boards of electrical equipment and products.

Fig. 1 shows a conventional stylus device of this kind, Fig. 1a shows the tip of the stylus 1, which is formed into an annular serrated shape, and Fig. 1b shows the tip of the stylus 1. FIG. 1 is a front view showing the overall configuration of the needle, and the stylus shown in FIG. 1b will be described below as an example.

As is clear from FIG. 1c, the stylus 1 shown in FIG. 1b is formed into a spear shape, and has a reduced diameter portion 1a near its tip. A groove 1b is provided near the lower end of the small diameter portion 1a.

A coiled spring 2 is inserted into this small diameter portion 1a as shown in FIG.
It is locked to. Next to spring 2, the first
As shown in Figure e, a cylindrical metal fitting 3 is inserted into the small diameter portion 1a, and the lower end of the spring 2 is locked to the tip of this metal fitting 3. That is, the spring 2 is interposed between the metal fitting 3 and the collar portion 1c.

After the metal fitting 3 is inserted, as shown in FIG. 1f, a notched annular washer 4 is fitted into the groove 1b of the small diameter portion 1a to prevent the metal fitting 3 from coming off.

Next, the operation of the conventional stylus device configured as described above will be described. FIG. 2 is a cross-sectional view showing the usage state of the above-mentioned stylus device. As shown in FIG. There is a force pushing upwards.

Further, the washer 4 fitted in the groove 1b of the small diameter portion 1a of the stylus 1 prevents the stylus 1 from coming off upwardly on the bottom surface of the metal fitting 3 due to the expanding elastic force of the spring 2.

With this operation, when the printed board 6 is mounted on the top of the stylus 1, the spring 2 pushes the stylus 1 in the direction of pushing the land provided on the printed board 6.
act to make electrical contact.

However, this stylus 1 has a sharp tip and stands perpendicular to the printed board 6. and,
Since the solder fillet has an angle of 90 degrees or less with respect to the printed circuit board 6, the conventional stylus described above cannot make stable contact with the land of the component lead.

Since the conventional stylus is constructed as described above, a stylus land must be provided separately in the pattern of the printed board 6, which requires extra time for designing the drawing of the printed board 6.

Furthermore, if the stylus land is not completely covered with solder, the flux may act as an insulator between the land and the stylus, resulting in poor contact with the checker. Furthermore, as a result, the amount of solder used has also increased, albeit in a small amount.

This invention was made in order to eliminate the above-mentioned conventional drawbacks, and the purpose is to provide a stylus that can eliminate the stylus land on the printed board by changing the shape of the stylus. .

Hereinafter, embodiments of the stylus of this invention will be described based on the drawings.

FIG. 3 is a sectional view showing the configuration of one embodiment. In FIG. 3, reference numeral 11 denotes a stylus in the form of a flat plate, which is provided at the tip of the support rod 12. As shown in FIG. A groove is formed on the outer peripheral surface of the support rod 12 at a predetermined location, and a notched annular washer 13 similar to that shown in FIG. 1f is fitted into this groove.

The upper portion of this washer 13 and the stylus 11 are inserted into a bottomed cylindrical metal fitting 14. In this metal fitting 14, a coil-shaped spring 15 is wound around the outer peripheral surface of the support rod 12 between the stylus 11 and the bottom of the metal fitting 14. The stylus 11 provided at the tip of the support rod 12 is inserted into the support rod 12 so that the washer 13 is housed in the bottomed cylindrical fitting 14 when the spring 15 is in its maximum expanded state. It is set in.

Next, the operation of the stylus device of this invention constructed as described above will be described with reference to FIG. 4. FIG. 4 is a sectional view showing how the stylus of this invention is used. As shown in FIG. 4, the metal fitting 14 is fixed to the stand of the checker 16, and the stylus 11 is pushed upward by the expanding elastic force of the spring 15.

Also, since the washer 13 is attached to the groove of the support rod 12 that supports the stylus 11, this washer 13 prevents the stylus 11 from protruding from the upper edge of the metal fitting 14 due to the expanding force of the spring 15. It is positioned so that it does not.

As a result, the printed board 19 is placed above the stylus 11.
When the solder fillet and lead 17 of the component 18 to be mounted are on top, the stylus 11 is pushed down, but since the stylus 11 is always pushed upward by the spring 15, the stylus 11 is pushed upward. needle 11
contacts lead 17 or solder fillet of component 18. At this time, the lead 17 is connected to the printed board 1.
It does not necessarily protrude in a direction perpendicular to 9, but in many cases it protrudes in an inclined state with respect to the perpendicular direction. Therefore, stress does not act on the stylus 11 only in the axial direction of the support rod 12, but a component force also acts on the stylus 11 in a direction perpendicular to the axial direction of the support rod 12.

Therefore, force is repeatedly applied to the support rod 12 in a direction perpendicular to its axial direction, causing it to move up and down in the axial direction while exhibiting a so-called shaking action.

However, according to the configuration of this invention, the stylus 1
Since the stylus 1 is configured to be moved up and down within the cylindrical metal fitting 14, even if a component force is applied in a direction perpendicular to the axial direction of the support rod 12, the end edge of the stylus 11 is moved up and down within the cylindrical metal fitting 14. Since the stylus 14 slides on the inner wall surface of the stylus 14 and moves up and down, excessive swinging motion of the stylus 11 and the support rod 12 is prevented.

FIGS. 5 and 6 are views showing modified examples of the stylus of this invention, respectively. In the above embodiment, the stylus 11 was in the shape of a flat plate, but in this FIG. FIG. 6 shows a case in which it is formed into a semicircular dish shape. This fifth
It goes without saying that the same effects as in the above embodiment can be achieved in both cases shown in FIG.

As mentioned above, according to the stylus device of this invention,
The stylus has a flat plate shape and is always guided by a cylindrical metal fitting, so the stylus can be brought into contact with the land where the lead of the component is (solder fillet and lead part). It is possible.

This eliminates the need to provide a special land for measurement on the printed board, shortens the time required to design printed board drawings, reduces the amount of solder used, and improves the reliability of the contact between the circuit unit and the checker. can be done.

Furthermore, it is possible to prevent the so-called oscillating motion that occurs when the stylus contacts the lead of a component on a printed circuit board, thereby further increasing the durability of this type of stylus device that is used repeatedly.

[Brief explanation of the drawing]

Figure 1a is a front view showing the tip of a conventional stylus;
Fig. 1b is a front view showing the overall structure of a conventional stylus, Fig. 1c is a front view showing the stylus portion of Fig. 1b, and Fig. 1d is a front view of the stylus shown in Fig. 1b. Figure 1e is a perspective view of the spring used; Figure 1f is a perspective view of the metal fitting used in the stylus of Figure 1b; Figure 1f is the same as Figure 1b.
FIG. 2 is a cross-sectional view showing the usage state of the conventional stylus, and FIG. 3 is a cross-sectional view showing the configuration of an embodiment of the stylus of this invention. 4 are sectional views showing how the stylus of this invention is used, and FIGS. 5 and 6 are front views of other embodiments of the stylus of this invention. 11... Stylus, 12... Support rod, 13... Washer, 14... Metal fitting, 16... Checker, 17
...Lead, 18...Parts, 19...Printed board.

Claims (1)

[Scope of utility model registration request] a support member inserted into a bottomed cylindrical metal fitting; a stylus member provided at the tip of the support member and having a flat plate shape; A locking portion is provided on the outer peripheral surface of the support member to prevent the support member from separating from the metal fitting due to the expanding elastic force of the spring, and is provided at the tip of the support member. The stylus device is characterized in that the locking portion is provided on the support member so that the stylus member is housed in a bottomed cylindrical metal fitting when the spring is in its maximum expanded state. .