JPS5828328Y2 - semi-fixed resistor - Google Patents

Description

[Detailed description of the invention] The invention relates to a semi-fixed resistor, which is rotated by caulking a rotating shaft fixed to a movable plate onto a board provided with a hole having a counterbore. It is an object of the present invention to provide a semi-fixed resistor that can be easily and reliably adjusted by freely mounting it, is easy to connect to an external circuit, and can be configured compactly.

In the conventional semi-fixed resistor, for example, as shown in FIG. 1, a movable plate 1 provided with a sliding piece 1' is inserted and fixed onto a rotating shaft 2.
Rotatably installed on the printed circuit board 4 via the spacer 3,
The sliding piece 1' was configured to slide into contact with a resistor (not shown) on a substrate 4.

However, in this case, the movable plate 1 and the rotating shaft 2 are simply fixed by inserting the oval-shaped shaft 2a into the oval-shaped hole 1a, so it is easy to cause looseness, and the rotating shaft 2 is Since the ring 5 fixed to the lower end is configured to prevent the board 4 from coming off in the upward direction, the installation area of the board 4 is large and a certain amount of thickness is required, making it difficult to downsize. There were drawbacks.

Furthermore, since the lead wire 6 is provided on the board 4, it is difficult to downsize, is weak against mechanical shock, is difficult to connect to an external circuit, and is also difficult to rotate the rotation shaft 2. In order to do this, the rotating shaft 2 had to be machined into a special shape, and a special driver had to be used.

The present invention eliminates the above-mentioned drawbacks, and one embodiment thereof will be described with reference to FIGS.

FIGS. 2A and 2B show a plan view and a vertical sectional view, respectively, of an embodiment of a semi-fixed resistor according to the present invention.

In the figure, reference numeral 7 denotes an insulating printed circuit board, which has a circular hole 7a and a counterbore 7a' in its center, and a notch 7b in its side, and a ring-shaped resistor with an end on its upper surface. A pair of first electrode portions 7d and 7e are printed continuously on both ends of the 7C1 resistor 7C over the side and back surfaces, and the electrode portion 7
Preliminary solder parts 7d', 7 on the side and back surfaces of d, 7e.
e' has been applied.

Note that due to the presence of the notch portion 7b, the pair of electrode portions 7d,
7e is reliably separated, so when dipping the side surface of the board 7 with solder to form preliminary solder parts 7d' and 7e',
There is no possibility that the electrode parts 7d and 7e will be short-circuited by the preliminary solder part.

In addition, 7f and 7f' are a second electrode part and a preliminary solder part for positioning and mounting reinforcement, respectively, and are provided on a part of the back surface of the board 7 to ensure that the board 7 is mounted on another circuit board. Proper positioning and installation will provide additional reinforcement.

As described above, since the electrodes 7d and 7e are provided on the substrate 7, there is no need to provide lead wires as in the conventional example, and the structure can be made smaller than the conventional one, strong against mechanical shock, and suitable for external circuits. Can be easily connected.

Reference numeral 8 denotes an annealed rotating shaft, the upper end of which is a circular plate with a groove 8a for fitting a flathead screwdriver, and the lower end with a caulking hole 8b of an appropriate depth.
Its lower end is inserted into the hole 7a of the board 7, and the caulking hole 8b
The peripheral edge is caulked inside the counterbore portion 7a' of the substrate 7 so as not to protrude from the back surface of the substrate 7, and is rotatably attached to the substrate 7.

In this way, since the groove 8a is provided in the disc part of the rotating shaft 8, it is easy to adjust the rotation by applying a general flat head screwdriver, etc. There is no need to change the settings or use a special driver.

In addition, since the base plate 7 is provided with a counterbore 7a' and the lower end of the rotating shaft 8 is brought into direct contact therewith and caulked, the mounting area and thickness to the base plate 7 can be reduced compared to conventional ones. Board 7
Since there is no downwardly protruding part, it is easy to attach other members below the substrate 7, and furthermore, since there is no need to provide a conventional ring or an intervening ring for caulking, the number of parts can be reduced.

Reference numeral 9 denotes a movable plate integrally provided with an elastic sliding piece 9a, the upper surface of which is spot welded to the lower surface of the circular plate of the rotating shaft 8, and the sliding piece 9a is connected to the resistor 7C of the substrate 7. It is attached to the substrate 7 via a spacer 10 so that it can come into contact with and slide along.

Note that the movable plate 9 is electrically connected to, for example, the electrode portion 7d through a conductive film (not shown) provided at its central portion.

In this way, since the movable plate 9 is spot welded to the rotating shaft 8, there is no play between the movable plate and the rotating shaft unlike in the conventional case, and the movable plate 9 and the rotating shaft 8 are Compared to structures that require soldering, this method is easier to work with, easier to automate, and has greater mounting strength.

As mentioned above, in the semi-fixed resistor of the present invention, the rotating shaft is caulked by directly contacting the through hole of the board with the inner surface of the counterbore so as not to protrude to the back surface of the board, so that the overall thickness can be reduced. It can be made smaller, the number of parts can be reduced and the configuration can be simplified without requiring an extra ring for caulking, and since the movable plate is fixed to the disc part of the rotating shaft by welding, there is no installation play. The mounting strength can be improved without any problems, and the installation can be automated to reduce assembly man-hours. Also, since a second electrode part is provided on the back of the board for reinforcing the mounting, the board can be easily attached to other rotating boards. The positioning accuracy and mounting strength can be improved during installation, and since the first electrode part can be used for mounting and electrical connection with other circuit boards, there is no need to provide leads as in the past, and the structure can be made smaller. It is strong against mechanical shock, easy to connect to an external circuit, and requires a small mounting area to other circuit boards, and each first electrode part is reliably separated by a cutout between them. Therefore, there is no risk of short-circuiting even when forming a preliminary solder portion, and reliability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an example of a conventional semi-fixed resistor, and FIGS. 2A and 2B are a plan view and a longitudinal sectional view, respectively, of an embodiment of the semi-fixed resistor according to the present invention. 7...Printed circuit board, 7a...hole, 7
a'...Counterbore, 7C...Resistor,
7 d, 7 e...electrode section, 8...
Rotation shaft, 8a...groove, 8b...hole, 9
......Movable plate, 9a...Sliding piece, 10.
·····Spacer.

Claims (1)

[Scope of utility model registration request] A resistor on the front surface, a first electrode part that is individually connected to both ends of the resistor and extends from the front surface to the back surface via the side surface, and a second electrode for mounting reinforcement that is independently provided on the back surface. an insulating substrate having a vertical through hole having a cutout portion provided to separate the first electrode portion into a plurality of portions, and a counterbore portion on the back side; and the substrate inserted through the through hole. a rotating shaft having a disk portion at an upper end portion on the front surface side and being caulked by contacting the inner surface of the counterbore portion so that the lower end portion protruding into the counterbore portion does not protrude to the back surface of the substrate; A semi-fixed resistor comprising a movable plate that is fitted onto the rotating shaft and fixed to the lower surface of the disc by welding, and has a sliding piece that can slide into contact with the resistor.